Commit Graph

768 Commits

Author SHA1 Message Date
Josef Bacik bab39bf998 Btrfs: use a worker thread to do caching
A user reported a deadlock when copying a bunch of files.  This is because they
were low on memory and kthreadd got hung up trying to migrate pages for an
allocation when starting the caching kthread.  The page was locked by the person
starting the caching kthread.  To fix this we just need to use the async thread
stuff so that the threads are already created and we don't have to worry about
deadlocks.  Thanks,

Reported-by: Roman Mamedov <rm@romanrm.ru>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-07-27 12:46:25 -04:00
Christoph Hellwig 4e34e719e4 fs: take the ACL checks to common code
Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25 14:30:23 -04:00
Josef Bacik 02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00
Josef Bacik b26751575a Btrfs: implement our own ->llseek
In order to handle SEEK_HOLE/SEEK_DATA we need to implement our own llseek.
Basically for the normal SEEK_*'s we will just defer to the generic helper, and
for SEEK_HOLE/SEEK_DATA we will use our fiemap helper to figure out the nearest
hole or data.  Currently this helper doesn't check for delalloc bytes for
prealloc space, so for now treat prealloc as data until that is fixed.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:56 -04:00
Al Viro 0ee5dc676a btrfs: kill magical embedded struct superblock
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:20 -04:00
Al Viro 7e40145eb1 ->permission() sanitizing: don't pass flags to ->check_acl()
not used in the instances anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:21 -04:00
Josef Bacik fdb5effd5c Btrfs: serialize flushers in reserve_metadata_bytes
We keep having problems with early enospc, and that's because our method of
making space is inherently racy.  The problem is we can have one guy trying to
make space for himself, and in the meantime people come in and steal his
reservation.  In order to stop this we make a waitqueue and put anybody who
comes into reserve_metadata_bytes on that waitqueue if somebody is trying to
make more space.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-07-11 09:58:48 -04:00
Josef Bacik b5009945be Btrfs: do transaction space reservation before joining the transaction
We have to do weird things when handling enospc in the transaction joining code.
Because we've already joined the transaction we cannot commit the transaction
within the reservation code since it will deadlock, so we have to return EAGAIN
and then make sure we don't retry too many times.  Instead of doing this, just
do the reservation the normal way before we join the transaction, that way we
can do whatever we want to try and reclaim space, and then if it fails we know
for sure we are out of space and we can return ENOSPC.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-07-11 09:58:47 -04:00
Linus Torvalds 1acc9309eb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  btrfs: fix oops when doing space balance
  Btrfs: don't panic if we get an error while balancing V2
  btrfs: add missing options displayed in mount output
2011-07-08 23:25:45 -07:00
David Sterba 0942caa373 btrfs: add missing options displayed in mount output
There are three missed mount options settable by user which are not
currently displayed in mount output.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-07-06 18:46:43 -04:00
Jesper Juhl 46e4edbf7e Remove unneeded version.h includes from fs/
It was pointed out by 'make versioncheck' that some includes of
linux/version.h were not needed in fs/ (fs/btrfs/ctree.h and
fs/omfs/file.c).

This patch removes them.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-24 08:34:22 -07:00
Linus Torvalds 90a800de0a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: avoid delayed metadata items during commits
  btrfs: fix uninitialized return value
  btrfs: fix wrong reservation when doing delayed inode operations
  btrfs: Remove unused sysfs code
  btrfs: fix dereference of ERR_PTR value
  Btrfs: fix relocation races
  Btrfs: set no_trans_join after trying to expand the transaction
  Btrfs: protect the pending_snapshots list with trans_lock
  Btrfs: fix path leakage on subvol deletion
  Btrfs: drop the delalloc_bytes check in shrink_delalloc
  Btrfs: check the return value from set_anon_super
2011-06-20 08:58:53 -07:00
Maarten Lankhorst 9fe6a50fb7 btrfs: Remove unused sysfs code
Removes code no longer used. The sysfs file itself is kept, because the
btrfs developers expressed interest in putting new entries to sysfs.

Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-17 14:54:18 -04:00
Chris Mason 7585717f30 Btrfs: fix relocation races
The recent commit to get rid of our trans_mutex introduced
some races with block group relocation.  The problem is that relocation
needs to do some record keeping about each root, and it was relying
on the transaction mutex to coordinate things in subtle ways.

This fix adds a mutex just for the relocation code and makes sure
it doesn't have a big impact on normal operations.  The race is
really fixed in btrfs_record_root_in_trans, which is where we
step back and wait for the relocation code to finish accounting
setup.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-17 13:36:58 -04:00
Linus Torvalds e6ece70732 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (25 commits)
  btrfs: fix uninitialized variable warning
  btrfs: add helper for fs_info->closing
  Btrfs: add mount -o inode_cache
  btrfs: scrub: add explicit plugging
  btrfs: use btrfs_ino to access inode number
  Btrfs: don't save the inode cache if we are deleting this root
  btrfs: false BUG_ON when degraded
  Btrfs: don't save the inode cache in non-FS roots
  Btrfs: make sure we don't overflow the free space cache crc page
  Btrfs: fix uninit variable in the delayed inode code
  btrfs: scrub: don't reuse bios and pages
  Btrfs: leave spinning on lookup and map the leaf
  Btrfs: check for duplicate entries in the free space cache
  Btrfs: don't try to allocate from a block group that doesn't have enough space
  Btrfs: don't always do readahead
  Btrfs: try not to sleep as much when doing slow caching
  Btrfs: kill BTRFS_I(inode)->block_group
  Btrfs: don't look at the extent buffer level 3 times in a row
  Btrfs: map the node block when looking for readahead targets
  Btrfs: set range_start to the right start in count_range_bits
  ...
2011-06-05 06:17:23 +09:00
David Sterba 7841cb2898 btrfs: add helper for fs_info->closing
wrap checking of filesystem 'closing' flag and fix a few missing memory
barriers.

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-06-04 08:11:22 -04:00
Chris Mason 4b9465cb9e Btrfs: add mount -o inode_cache
This makes the inode map cache default to off until we
fix the overflow problem when the free space crcs don't fit
inside a single page.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-04 08:03:47 -04:00
Linus Torvalds 36947a7682 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (36 commits)
  Cache xattr security drop check for write v2
  fs: block_page_mkwrite should wait for writeback to finish
  mm: Wait for writeback when grabbing pages to begin a write
  configfs: remove unnecessary dentry_unhash on rmdir, dir rename
  fat: remove unnecessary dentry_unhash on rmdir, dir rename
  hpfs: remove unnecessary dentry_unhash on rmdir, dir rename
  minix: remove unnecessary dentry_unhash on rmdir, dir rename
  fuse: remove unnecessary dentry_unhash on rmdir, dir rename
  coda: remove unnecessary dentry_unhash on rmdir, dir rename
  afs: remove unnecessary dentry_unhash on rmdir, dir rename
  affs: remove unnecessary dentry_unhash on rmdir, dir rename
  9p: remove unnecessary dentry_unhash on rmdir, dir rename
  ncpfs: fix rename over directory with dangling references
  ncpfs: document dentry_unhash usage
  ecryptfs: remove unnecessary dentry_unhash on rmdir, dir rename
  hostfs: remove unnecessary dentry_unhash on rmdir, dir rename
  hfsplus: remove unnecessary dentry_unhash on rmdir, dir rename
  hfs: remove unnecessary dentry_unhash on rmdir, dir rename
  omfs: remove unnecessary dentry_unhash on rmdir, dir rneame
  udf: remove unnecessary dentry_unhash from rmdir, dir rename
  ...
2011-05-28 13:03:41 -07:00
Chris Mason ff5714cca9 Merge branch 'for-chris' of
git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into for-linus

Conflicts:
	fs/btrfs/disk-io.c
	fs/btrfs/extent-tree.c
	fs/btrfs/free-space-cache.c
	fs/btrfs/inode.c
	fs/btrfs/transaction.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-28 07:00:39 -04:00
Christoph Hellwig aa38572954 fs: pass exact type of data dirties to ->dirty_inode
Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.

This is just the prototype change with no user for it yet.  I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.

Also remove incorrect comments that ->dirty_inode can't block.  That
has been changed a long time ago, and many implementations rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27 07:04:40 -04:00
Chris Mason 4cb5300bc8 Btrfs: add mount -o auto_defrag
This will detect small random writes into files and
queue the up for an auto defrag process.  It isn't well suited to
database workloads yet, but works for smaller files such as rpm, sqlite
or bdb databases.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-26 17:52:15 -04:00
Chris Mason d6c0cb379c Merge branch 'cleanups_and_fixes' into inode_numbers
Conflicts:
	fs/btrfs/tree-log.c
	fs/btrfs/volumes.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23 14:37:47 -04:00
Andi Kleen 0956c798ef BTRFS: Remove unused node_lock
240f62c875 replaced the node_lock with rcu_read_lock, but forgot
to remove the actual lock in the data structure. Remove it here.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23 13:05:39 -04:00
Josef Bacik d82a6f1d7e Btrfs: kill BTRFS_I(inode)->block_group
Originally this was going to be used as a way to give hints to the allocator,
but frankly we can get much better hints elsewhere and it's not even used at all
for anything usefull.  In addition to be completely useless, when we initialize
an inode we try and find a freeish block group to set as the inodes block group,
and with a completely full 40gb fs this takes _forever_, so I imagine with say
1tb fs this is just unbearable.  So just axe the thing altoghether, we don't
need it and it saves us 8 bytes in the inode and saves us 500 microseconds per
inode lookup in my testcase.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:03:12 -04:00
Josef Bacik fcb80c2aff Btrfs: fix how we do space reservation for truncate
The ceph guys keep running into problems where we have space reserved in our
orphan block rsv when freeing it up.  This is because they tend to do snapshots
alot, so their truncates tend to use a bunch of space, so when we go to do
things like update the inode we have to steal reservation space in order to make
the reservation happen.  This happens because truncate can use as much space as
it freaking feels like, but we still have to hold space for removing the orphan
item and updating the inode, which will definitely always happen.  So in order
to fix this we need to split all of the reservation stuf up.  So with this patch
we have

1) The orphan block reserve which only holds the space for deleting our orphan
item when everything is over.

2) The truncate block reserve which gets allocated and used specifically for the
space that the truncate will use on a per truncate basis.

3) The transaction will always have 1 item's worth of data reserved so we can
update the inode normally.

Hopefully this will make the ceph problem go away.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:03:08 -04:00
Josef Bacik a4abeea41a Btrfs: kill trans_mutex
We use trans_mutex for lots of things, here's a basic list

1) To serialize trans_handles joining the currently running transaction
2) To make sure that no new trans handles are started while we are committing
3) To protect the dead_roots list and the transaction lists

Really the serializing trans_handles joining is not too hard, and can really get
bogged down in acquiring a reference to the transaction.  So replace the
trans_mutex with a trans_lock spinlock and use it to do the following

1) Protect fs_info->running_transaction.  All trans handles have to do is check
this, and then take a reference of the transaction and keep on going.
2) Protect the fs_info->trans_list.  This doesn't get used too much, basically
it just holds the current transactions, which will usually just be the currently
committing transaction and the currently running transaction at most.
3) Protect the dead roots list.  This is only ever processed by splicing the
list so this is relatively simple.
4) Protect the fs_info->reloc_ctl stuff.  This is very lightweight and was using
the trans_mutex before, so this is a pretty straightforward change.
5) Protect fs_info->no_trans_join.  Because we don't hold the trans_lock over
the entirety of the commit we need to have a way to block new people from
creating a new transaction while we're doing our work.  So we set no_trans_join
and in join_transaction we test to see if that is set, and if it is we do a
wait_on_commit.
6) Make the transaction use count atomic so we don't need to take locks to
modify it when we're dropping references.
7) Add a commit_lock to the transaction to make sure multiple people trying to
commit the same transaction don't race and commit at the same time.
8) Make open_ioctl_trans an atomic so we don't have to take any locks for ioctl
trans.

I have tested this with xfstests, but obviously it is a pretty hairy change so
lots of testing is greatly appreciated.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:00:57 -04:00
Chris Mason 712673339a Merge branch 'for-chris' of git://git.kernel.org/pub/scm/linux/kernel/git/arne/btrfs-unstable-arne into inode_numbers
Conflicts:
	fs/btrfs/Makefile
	fs/btrfs/ctree.h
	fs/btrfs/volumes.h

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23 06:30:52 -04:00
Chris Mason 945d8962ce Merge branch 'cleanups' of git://repo.or.cz/linux-2.6/btrfs-unstable into inode_numbers
Conflicts:
	fs/btrfs/extent-tree.c
	fs/btrfs/free-space-cache.c
	fs/btrfs/inode.c
	fs/btrfs/tree-log.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-22 12:33:42 -04:00
Chris Mason dcc6d07322 Merge branch 'delayed_inode' into inode_numbers
Conflicts:
	fs/btrfs/inode.c
	fs/btrfs/ioctl.c
	fs/btrfs/transaction.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-22 07:07:01 -04:00
Miao Xie 16cdcec736 btrfs: implement delayed inode items operation
Changelog V5 -> V6:
- Fix oom when the memory load is high, by storing the delayed nodes into the
  root's radix tree, and letting btrfs inodes go.

Changelog V4 -> V5:
- Fix the race on adding the delayed node to the inode, which is spotted by
  Chris Mason.
- Merge Chris Mason's incremental patch into this patch.
- Fix deadlock between readdir() and memory fault, which is reported by
  Itaru Kitayama.

Changelog V3 -> V4:
- Fix nested lock, which is reported by Itaru Kitayama, by updating space cache
  inode in time.

Changelog V2 -> V3:
- Fix the race between the delayed worker and the task which does delayed items
  balance, which is reported by Tsutomu Itoh.
- Modify the patch address David Sterba's comment.
- Fix the bug of the cpu recursion spinlock, reported by Chris Mason

Changelog V1 -> V2:
- break up the global rb-tree, use a list to manage the delayed nodes,
  which is created for every directory and file, and used to manage the
  delayed directory name index items and the delayed inode item.
- introduce a worker to deal with the delayed nodes.

Compare with Ext3/4, the performance of file creation and deletion on btrfs
is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
such as inode item, directory name item, directory name index and so on.

If we can do some delayed b+ tree insertion or deletion, we can improve the
performance, so we made this patch which implemented delayed directory name
index insertion/deletion and delayed inode update.

Implementation:
- introduce a delayed root object into the filesystem, that use two lists to
  manage the delayed nodes which are created for every file/directory.
  One is used to manage all the delayed nodes that have delayed items. And the
  other is used to manage the delayed nodes which is waiting to be dealt with
  by the work thread.
- Every delayed node has two rb-tree, one is used to manage the directory name
  index which is going to be inserted into b+ tree, and the other is used to
  manage the directory name index which is going to be deleted from b+ tree.
- introduce a worker to deal with the delayed operation. This worker is used
  to deal with the works of the delayed directory name index items insertion
  and deletion and the delayed inode update.
  When the delayed items is beyond the lower limit, we create works for some
  delayed nodes and insert them into the work queue of the worker, and then
  go back.
  When the delayed items is beyond the upper bound, we create works for all
  the delayed nodes that haven't been dealt with, and insert them into the work
  queue of the worker, and then wait for that the untreated items is below some
  threshold value.
- When we want to insert a directory name index into b+ tree, we just add the
  information into the delayed inserting rb-tree.
  And then we check the number of the delayed items and do delayed items
  balance. (The balance policy is above.)
- When we want to delete a directory name index from the b+ tree, we search it
  in the inserting rb-tree at first. If we look it up, just drop it. If not,
  add the key of it into the delayed deleting rb-tree.
  Similar to the delayed inserting rb-tree, we also check the number of the
  delayed items and do delayed items balance.
  (The same to inserting manipulation)
- When we want to update the metadata of some inode, we cached the data of the
  inode into the delayed node. the worker will flush it into the b+ tree after
  dealing with the delayed insertion and deletion.
- We will move the delayed node to the tail of the list after we access the
  delayed node, By this way, we can cache more delayed items and merge more
  inode updates.
- If we want to commit transaction, we will deal with all the delayed node.
- the delayed node will be freed when we free the btrfs inode.
- Before we log the inode items, we commit all the directory name index items
  and the delayed inode update.

I did a quick test by the benchmark tool[1] and found we can improve the
performance of file creation by ~15%, and file deletion by ~20%.

Before applying this patch:
Create files:
        Total files: 50000
        Total time: 1.096108
        Average time: 0.000022
Delete files:
        Total files: 50000
        Total time: 1.510403
        Average time: 0.000030

After applying this patch:
Create files:
        Total files: 50000
        Total time: 0.932899
        Average time: 0.000019
Delete files:
        Total files: 50000
        Total time: 1.215732
        Average time: 0.000024

[1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3

Many thanks for Kitayama-san's help!

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dave@jikos.cz>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-21 09:30:56 -04:00
Chris Mason 0965537308 Merge branch 'ino-alloc' of git://repo.or.cz/linux-btrfs-devel into inode_numbers
Conflicts:
	fs/btrfs/free-space-cache.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-21 09:27:38 -04:00
David Sterba 4ea028859b btrfs: use unsigned type for single bit bitfield
Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-12 18:14:53 +02:00
Arne Jansen 8628764e1a btrfs: add readonly flag
setting the readonly flag prevents writes in case an error is detected

Signed-off-by: Arne Jansen <sensille@gmx.net>
2011-05-12 14:48:31 +02:00
Jan Schmidt 475f63874d btrfs: new ioctls for scrub
adds ioctls necessary to start and cancel scrubs, to get current
progress and to get info about devices to be scrubbed.
Note that the scrub is done per-device and that the ioctl only
returns after the scrub for this devices is finished or has been
canceled.

Signed-off-by: Arne Jansen <sensille@gmx.net>
2011-05-12 14:45:38 +02:00
Arne Jansen a2de733c78 btrfs: scrub
This adds an initial implementation for scrub. It works quite
straightforward. The usermode issues an ioctl for each device in the
fs. For each device, it enumerates the allocated device chunks. For
each chunk, the contained extents are enumerated and the data checksums
fetched. The extents are read sequentially and the checksums verified.
If an error occurs (checksum or EIO), a good copy is searched for. If
one is found, the bad copy will be rewritten.
All enumerations happen from the commit roots. During a transaction
commit, the scrubs get paused and afterwards continue from the new
roots.

This commit is based on the series originally posted to linux-btrfs
with some improvements that resulted from comments from David Sterba,
Ilya Dryomov and Jan Schmidt.

Signed-off-by: Arne Jansen <sensille@gmx.net>
2011-05-12 14:45:20 +02:00
David Sterba f2a97a9dbd btrfs: remove all unused functions
Remove static and global declarations and/or definitions. Reduces size
of btrfs.ko by ~3.4kB.

  text    data     bss     dec     hex filename
402081    7464     200  409745   64091 btrfs.ko.base
398620    7144     200  405964   631cc btrfs.ko.remove-all

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-06 12:34:03 +02:00
David Sterba 621496f4fd btrfs: remove unused function prototypes
function prototypes without a body

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-04 14:01:26 +02:00
David Sterba b3b4aa74b5 btrfs: drop unused parameter from btrfs_release_path
parameter tree root it's not used since commit
5f39d397df ("Btrfs: Create extent_buffer
interface for large blocksizes")

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:22 +02:00
David Sterba 306e16ce13 btrfs: rename variables clashing with global function names
reported by gcc -Wshadow:
page_index, page_offset, new_inode, dev_name

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:19 +02:00
Lucas De Marchi e9c549998d Revert wrong fixes for common misspellings
These changes were incorrectly fixed by codespell. They were now
manually corrected.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-04-26 23:31:11 -07:00
Li Zefan 82d5902d9c Btrfs: Support reading/writing on disk free ino cache
This is similar to block group caching.

We dedicate a special inode in fs tree to save free ino cache.

At the very first time we create/delete a file after mount, the free ino
cache will be loaded from disk into memory. When the fs tree is commited,
the cache will be written back to disk.

To keep compatibility, we check the root generation against the generation
of the special inode when loading the cache, so the loading will fail
if the btrfs filesystem was mounted in an older kernel before.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:11 +08:00
Li Zefan 581bb05094 Btrfs: Cache free inode numbers in memory
Currently btrfs stores the highest objectid of the fs tree, and it always
returns (highest+1) inode number when we create a file, so inode numbers
won't be reclaimed when we delete files, so we'll run out of inode numbers
as we keep create/delete files in 32bits machines.

This fixes it, and it works similarly to how we cache free space in block
cgroups.

We start a kernel thread to read the file tree. By scanning inode items,
we know which chunks of inode numbers are free, and we cache them in
an rb-tree.

Because we are searching the commit root, we have to carefully handle the
cross-transaction case.

The rb-tree is a hybrid extent+bitmap tree, so if we have too many small
chunks of inode numbers, we'll use bitmaps. Initially we allow 16K ram
of extents, and a bitmap will be used if we exceed this threshold. The
extents threshold is adjusted in runtime.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:04 +08:00
Li Zefan 34d52cb6c5 Btrfs: Make free space cache code generic
So we can re-use the code to cache free inode numbers.

The change is quite straightforward. Two new structures are introduced.

- struct btrfs_free_space_ctl

  We move those variables that are used for caching free space from
  struct btrfs_block_group_cache to this new struct.

- struct btrfs_free_space_op

  We do block group specific work (e.g. calculation of extents threshold)
  through functions registered in this struct.

And then we can remove references to struct btrfs_block_group_cache.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:03 +08:00
Josef Bacik 6d74119f1a Btrfs: avoid taking the chunk_mutex in do_chunk_alloc
Everytime we try to allocate disk space we try and see if we can pre-emptively
allocate a chunk, but in the common case we don't allocate anything, so there is
no sense in taking the chunk_mutex at all.  So instead if we are allocating a
chunk, mark it in the space_info so we don't get two people trying to allocate
at the same time.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Reviewed-by: Liu Bo <liubo2009@cn.fujitsu.com>
2011-04-16 07:10:56 -04:00
Josef Bacik be1a12a0df Btrfs: deal with the case that we run out of space in the cache
Currently we don't handle running out of space in the cache, so to fix this we
keep track of how far in the cache we are.  Then we only dirty the pages if we
successfully modify all of them, otherwise if we have an error or run out of
space we can just drop them and not worry about the vm writing them out.
Thanks,

Tested-by Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-04-08 13:00:27 -04:00
Li Zefan 08fe4db170 Btrfs: Fix uninitialized root flags for subvolumes
root_item->flags and root_item->byte_limit are not initialized when
a subvolume is created. This bug is not revealed until we added
readonly snapshot support - now you mount a btrfs filesystem and you
may find the subvolumes in it are readonly.

To work around this problem, we steal a bit from root_item->inode_item->flags,
and use it to indicate if those fields have been properly initialized.
When we read a tree root from disk, we check if the bit is set, and if
not we'll set the flag and initialize the two fields of the root item.

Reported-by: Andreas Philipp <philipp.andreas@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Andreas Philipp <philipp.andreas@gmail.com>
cc: stable@kernel.org
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-04-05 01:20:24 -04:00
liubo c59021f846 Btrfs: fix OOPS of empty filesystem after balance
btrfs will remove unused block groups after balance.
When a empty filesystem is balanced, the block group with tag "DATA" may be
dropped, and after umount and mount again, it will not find "DATA" space_info
and lead to OOPS.
So we initial the necessary space_infos(DATA, SYSTEM, METADATA) to avoid OOPS.

Reported-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:53 -04:00
Li Dongyang f7039b1d5c Btrfs: add btrfs_trim_fs() to handle FITRIM
We take an free extent out from allocator, trim it, then put it back,
but before we trim the block group, we should make sure the block group is
cached, so plus a little change to make cache_block_group() run without a
transaction.

Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:47 -04:00
Li Dongyang 5378e60734 Btrfs: adjust btrfs_discard_extent() return errors and trimmed bytes
Callers of btrfs_discard_extent() should check if we are mounted with -o discard,
as we want to make fitrim to work even the fs is not mounted with -o discard.
Also we should use REQ_DISCARD to map the free extent to get a full mapping,
last we only return errors if
1. the error is not a EOPNOTSUPP
2. no device supports discard

Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:46 -04:00
Li Dongyang b4d00d569a Btrfs: make update_reserved_bytes() public
Make the function public as we should update the reserved extents calculations
after taking out an extent for trimming.

Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:43 -04:00
Liu Bo 75e7cb7fe0 Btrfs: Per file/directory controls for COW and compression
Data compression and data cow are controlled across the entire FS by mount
options right now.  ioctls are needed to set this on a per file or per
directory basis.  This has been proposed previously, but VFS developers
wanted us to use generic ioctls rather than btrfs-specific ones.

According to Chris's comment, there should be just one true compression
method(probably LZO) stored in the super.  However, before this, we would
wait for that one method is stable enough to be adopted into the super.
So I list it as a long term goal, and just store it in ram today.

After applying this patch, we can use the generic "FS_IOC_SETFLAGS" ioctl to
control file and directory's datacow and compression attribute.

NOTE:
 - The compression type is selected by such rules:
   If we mount btrfs with compress options, ie, zlib/lzo, the type is it.
   Otherwise, we'll use the default compress type (zlib today).

v1->v2:
- rebase to the latest btrfs.
v2->v3:
- fix a problem, i.e. when a file is set NOCOW via mount option, then this NOCOW
  will be screwed by inheritance from parent directory.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:41 -04:00
liubo 1abe9b8a13 Btrfs: add initial tracepoint support for btrfs
Tracepoints can provide insight into why btrfs hits bugs and be greatly
helpful for debugging, e.g
              dd-7822  [000]  2121.641088: btrfs_inode_request: root = 5(FS_TREE), gen = 4, ino = 256, blocks = 8, disk_i_size = 0, last_trans = 8, logged_trans = 0
              dd-7822  [000]  2121.641100: btrfs_inode_new: root = 5(FS_TREE), gen = 8, ino = 257, blocks = 0, disk_i_size = 0, last_trans = 0, logged_trans = 0
 btrfs-transacti-7804  [001]  2146.935420: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29368320 (orig_level = 0), cow_buf = 29388800 (cow_level = 0)
 btrfs-transacti-7804  [001]  2146.935473: btrfs_cow_block: root = 1(ROOT_TREE), refs = 2, orig_buf = 29364224 (orig_level = 0), cow_buf = 29392896 (cow_level = 0)
 btrfs-transacti-7804  [001]  2146.972221: btrfs_transaction_commit: root = 1(ROOT_TREE), gen = 8
   flush-btrfs-2-7821  [001]  2155.824210: btrfs_chunk_alloc: root = 3(CHUNK_TREE), offset = 1103101952, size = 1073741824, num_stripes = 1, sub_stripes = 0, type = DATA
   flush-btrfs-2-7821  [001]  2155.824241: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29388800 (orig_level = 0), cow_buf = 29396992 (cow_level = 0)
   flush-btrfs-2-7821  [001]  2155.824255: btrfs_cow_block: root = 4(DEV_TREE), refs = 2, orig_buf = 29372416 (orig_level = 0), cow_buf = 29401088 (cow_level = 0)
   flush-btrfs-2-7821  [000]  2155.824329: btrfs_cow_block: root = 3(CHUNK_TREE), refs = 2, orig_buf = 20971520 (orig_level = 0), cow_buf = 20975616 (cow_level = 0)
 btrfs-endio-wri-7800  [001]  2155.898019: btrfs_cow_block: root = 5(FS_TREE), refs = 2, orig_buf = 29384704 (orig_level = 0), cow_buf = 29405184 (cow_level = 0)
 btrfs-endio-wri-7800  [001]  2155.898043: btrfs_cow_block: root = 7(CSUM_TREE), refs = 2, orig_buf = 29376512 (orig_level = 0), cow_buf = 29409280 (cow_level = 0)

Here is what I have added:

1) ordere_extent:
        btrfs_ordered_extent_add
        btrfs_ordered_extent_remove
        btrfs_ordered_extent_start
        btrfs_ordered_extent_put

These provide critical information to understand how ordered_extents are
updated.

2) extent_map:
        btrfs_get_extent

extent_map is used in both read and write cases, and it is useful for tracking
how btrfs specific IO is running.

3) writepage:
        __extent_writepage
        btrfs_writepage_end_io_hook

Pages are cirtical resourses and produce a lot of corner cases during writeback,
so it is valuable to know how page is written to disk.

4) inode:
        btrfs_inode_new
        btrfs_inode_request
        btrfs_inode_evict

These can show where and when a inode is created, when a inode is evicted.

5) sync:
        btrfs_sync_file
        btrfs_sync_fs

These show sync arguments.

6) transaction:
        btrfs_transaction_commit

In transaction based filesystem, it will be useful to know the generation and
who does commit.

7) back reference and cow:
	btrfs_delayed_tree_ref
	btrfs_delayed_data_ref
	btrfs_delayed_ref_head
	btrfs_cow_block

Btrfs natively supports back references, these tracepoints are helpful on
understanding btrfs's COW mechanism.

8) chunk:
	btrfs_chunk_alloc
	btrfs_chunk_free

Chunk is a link between physical offset and logical offset, and stands for space
infomation in btrfs, and these are helpful on tracing space things.

9) reserved_extent:
	btrfs_reserved_extent_alloc
	btrfs_reserved_extent_free

These can show how btrfs uses its space.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:33 -04:00
Josef Bacik 4e69b598f6 Btrfs: cleanup how we setup free space clusters
This patch makes the free space cluster refilling code a little easier to
understand, and fixes some things with the bitmap part of it.  Currently we
either want to refill a cluster with

1) All normal extent entries (those without bitmaps)
2) A bitmap entry with enough space

The current code has this ugly jump around logic that will first try and fill up
the cluster with extent entries and then if it can't do that it will try and
find a bitmap to use.  So instead split this out into two functions, one that
tries to find only normal entries, and one that tries to find bitmaps.

This also fixes a suboptimal thing we would do with bitmaps.  If we used a
bitmap we would just tell the cluster that we were pointing at a bitmap and it
would do the tree search in the block group for that entry every time we tried
to make an allocation.  Instead of doing that now we just add it to the clusters
group.

I tested this with my ENOSPC tests and xfstests and it survived.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-25 19:08:08 -04:00
Josef Bacik 22a94d44bd Btrfs: add checks to verify dir items are correct
We need to make sure the dir items we get are valid dir items.  So any time we
try and read one check it with verify_dir_item, which will do various sanity
checks to make sure it looks sane.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:41 -04:00
Josef Bacik 66b4ffd110 Btrfs: handle errors in btrfs_orphan_cleanup
If we cannot truncate an inode for some reason we will never delete the orphan
item associated with that inode, which means that we will loop forever in
btrfs_orphan_cleanup.  Instead of doing this just return error so we fail to
mount.  It sucks, but hey it's better than hanging.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:26 -04:00
Josef Bacik a41ad394a0 Btrfs: convert to the new truncate sequence
->truncate() is going away, instead all of the work needs to be done in
->setattr().  So this converts us over to do this.  It's fairly straightforward,
just get rid of our .truncate inode operation and call btrfs_truncate() directly
from btrfs_setsize.  This works out better for us since truncate can technically
return ENOSPC, and before we had no way of letting anybody know.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:22 -04:00
Josef Bacik dc89e98244 Btrfs: use a slab for the free space entries
Since we alloc/free free space entries a whole lot, lets use a slab to keep
track of them.  This makes some of my tests slightly faster.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:20 -04:00
Linus Torvalds 0e5b88cd99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: break out of shrink_delalloc earlier
  btrfs: fix not enough reserved space
  btrfs: fix dip leak
  Btrfs: make sure not to return overlapping extents to fiemap
  Btrfs: deal with short returns from copy_from_user
  Btrfs: fix regressions in copy_from_user handling
2011-03-13 16:00:49 -07:00
Chris Mason 36e39c40b3 Btrfs: break out of shrink_delalloc earlier
Josef had changed shrink_delalloc to exit after three shrink
attempts, which wasn't quite enough because new writers could
race in and steal free space.

But it also fixed deadlocks and stalls as we tried to recover
delalloc reservations.  The code was tweaked to loop 1024
times, and would reset the counter any time a small amount
of progress was made.  This was too drastic, and with a
lot of writers we can end up stuck in shrink_delalloc forever.

The shrink_delalloc loop is fairly complex because the caller is looping
too, and the caller will go ahead and force a transaction commit to make
sure we reclaim space.

This reworks things to exit shrink_delalloc when we've forced some
writeback and the delalloc reservations have gone down.  This means
the writeback has not just started but has also finished at
least some of the metadata changes required to reclaim delalloc
space.

If we've got this wrong, we're returning ENOSPC too early, which
is a big improvement over the current behavior of hanging the machine.

Test 224 in xfstests hammers on this nicely, and with 1000 writers
trying to fill a 1GB drive we get our first ENOSPC at 93% full.  The
other writers are able to continue until we get 100%.

This is a worst case test for btrfs because the 1000 writers are doing
small IO, and the small FS size means we don't have a lot of room
for metadata chunks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-12 07:08:42 -05:00
Linus Torvalds 4660ba63f1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix fiemap bugs with delalloc
  Btrfs: set FMODE_EXCL in btrfs_device->mode
  Btrfs: make btrfs_rm_device() fail gracefully
  Btrfs: Avoid accessing unmapped kernel address
  Btrfs: Fix BTRFS_IOC_SUBVOL_SETFLAGS ioctl
  Btrfs: allow balance to explicitly allocate chunks as it relocates
  Btrfs: put ENOSPC debugging under a mount option
2011-02-25 14:03:39 -08:00
Chris Mason c87f08ca44 Btrfs: allow balance to explicitly allocate chunks as it relocates
Btrfs device shrinking and balancing ends up reallocating all the blocks
in order to allow COW to move them to new destinations.  It is somewhat
awkward in terms of ENOSPC because most of the enospc code is built
around the idea that some operation on a reference counted tree triggers
allocations in the non-reference counted trees.

This commit changes the balancing code to deal with enospc by trying to
allocate a new chunk.  If that allocation succeeds, we go ahead and
retry whatever failed due to enospc.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-16 15:28:47 -05:00
Chris Mason 91435650c2 Btrfs: put ENOSPC debugging under a mount option
ENOSPC in btrfs is getting to the point where the extra debugging isn't
required.  I've put it under mount -o enospc_debug just in case someone
is having difficult problems.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-16 15:28:36 -05:00
Linus Torvalds eee2a817df Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (25 commits)
  Btrfs: forced readonly mounts on errors
  btrfs: Require CAP_SYS_ADMIN for filesystem rebalance
  Btrfs: don't warn if we get ENOSPC in btrfs_block_rsv_check
  btrfs: Fix memory leak in btrfs_read_fs_root_no_radix()
  btrfs: check NULL or not
  btrfs: Don't pass NULL ptr to func that may deref it.
  btrfs: mount failure return value fix
  btrfs: Mem leak in btrfs_get_acl()
  btrfs: fix wrong free space information of btrfs
  btrfs: make the chunk allocator utilize the devices better
  btrfs: restructure find_free_dev_extent()
  btrfs: fix wrong calculation of stripe size
  btrfs: try to reclaim some space when chunk allocation fails
  btrfs: fix wrong data space statistics
  fs/btrfs: Fix build of ctree
  Btrfs: fix off by one while setting block groups readonly
  Btrfs: Add BTRFS_IOC_SUBVOL_GETFLAGS/SETFLAGS ioctls
  Btrfs: Add readonly snapshots support
  Btrfs: Refactor btrfs_ioctl_snap_create()
  btrfs: Extract duplicate decompress code
  ...
2011-01-17 14:43:43 -08:00
liubo acce952b02 Btrfs: forced readonly mounts on errors
This patch comes from "Forced readonly mounts on errors" ideas.

As we know, this is the first step in being more fault tolerant of disk
corruptions instead of just using BUG() statements.

The major content:
- add a framework for generating errors that should result in filesystems
  going readonly.
- keep FS state in disk super block.
- make sure that all of resource will be freed and released at umount time.
- make sure that fter FS is forced readonly on error, there will be no more
  disk change before FS is corrected. For this, we should stop write operation.

After this patch is applied, the conversion from BUG() to such a framework can
happen incrementally.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-17 15:13:08 -05:00
Stefan Schmidt f8b18087fd fs/btrfs: Fix build of ctree
Fix the build failure in some configurations:

     CC [M]  fs/btrfs/ctree.o
  In file included from fs/btrfs/ctree.c:21:0:
  fs/btrfs/ctree.h:1003:17: error: field 'super_kobj' has incomplete type
  fs/btrfs/ctree.h:1074:17: error: field 'root_kobj' has incomplete type
  make[2]: *** [fs/btrfs/ctree.o] Error 1
  make[1]: *** [fs/btrfs] Error 2
  make: *** [fs] Error 2

caused by commit 57cc7215b7 ("headers: kobject.h redux")

We need to include kobject.h here.

Reported-by: Jeff Garzik <jeff@garzik.org>
Fix-suggested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-16 12:59:42 -08:00
Miao Xie 6d07bcec96 btrfs: fix wrong free space information of btrfs
When we store data by raid profile in btrfs with two or more different size
disks, df command shows there is some free space in the filesystem, but the
user can not write any data in fact, df command shows the wrong free space
information of btrfs.

 # mkfs.btrfs -d raid1 /dev/sda9 /dev/sda10
 # btrfs-show
 Label: none  uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
 	Total devices 2 FS bytes used 28.00KB
 	devid    1 size 5.01GB used 2.03GB path /dev/sda9
 	devid    2 size 10.00GB used 2.01GB path /dev/sda10
 # btrfs device scan /dev/sda9 /dev/sda10
 # mount /dev/sda9 /mnt
 # dd if=/dev/zero of=tmpfile0 bs=4K count=9999999999
   (fill the filesystem)
 # sync
 # df -TH
 Filesystem	Type	Size	Used	Avail	Use%	Mounted on
 /dev/sda9	btrfs	17G	8.6G	5.4G	62%	/mnt
 # btrfs-show
 Label: none  uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
 	Total devices 2 FS bytes used 3.99GB
 	devid    1 size 5.01GB used 5.01GB path /dev/sda9
 	devid    2 size 10.00GB used 4.99GB path /dev/sda10

It is because btrfs cannot allocate chunks when one of the pairing disks has
no space, the free space on the other disks can not be used for ever, and should
be subtracted from the total space, but btrfs doesn't subtract this space from
the total. It is strange to the user.

This patch fixes it by calcing the free space that can be used to allocate
chunks.

Implementation:
1. get all the devices free space, and align them by stripe length.
2. sort the devices by the free space.
3. check the free space of the devices,
   3.1. if it is not zero, and then check the number of the devices that has
        more free space than this device,
        if the number of the devices is beyond the min stripe number, the free
        space can be used, and add into total free space.
        if the number of the devices is below the min stripe number, we can not
        use the free space, the check ends.
   3.2. if the free space is zero, check the next devices, goto 3.1

This implementation is just likely fake chunk allocation.

After appling this patch, df can show correct space information:
 # df -TH
 Filesystem	Type	Size	Used	Avail	Use%	Mounted on
 /dev/sda9	btrfs	17G	8.6G	0	100%	/mnt

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-16 11:30:19 -05:00
Stefan Schmidt f580eb0931 fs/btrfs: Fix build of ctree
CC [M]  fs/btrfs/ctree.o
In file included from fs/btrfs/ctree.c:21:0:
fs/btrfs/ctree.h:1003:17: error: field <91>super_kobj<92> has incomplete type
fs/btrfs/ctree.h:1074:17: error: field <91>root_kobj<92> has incomplete type
make[2]: *** [fs/btrfs/ctree.o] Error 1
make[1]: *** [fs/btrfs] Error 2
make: *** [fs] Error 2

We need to include kobject.h here.

Reported-by: Jeff Garzik <jeff@garzik.org>
Fix-suggested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-16 11:30:19 -05:00
Chris Mason f892436eb2 Merge branch 'lzo-support' of git://repo.or.cz/linux-btrfs-devel into btrfs-38 2011-01-16 11:25:54 -05:00
Nick Piggin b74c79e993 fs: provide rcu-walk aware permission i_ops
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:29 +11:00
Li Zefan b83cc9693f Btrfs: Add readonly snapshots support
Usage:

Set BTRFS_SUBVOL_RDONLY of btrfs_ioctl_vol_arg_v2->flags, and call
ioctl(BTRFS_I0CTL_SNAP_CREATE_V2).

Implementation:

- Set readonly bit of btrfs_root_item->flags.
- Add readonly checks in btrfs_permission (inode_permission),
btrfs_setattr, btrfs_set/remove_xattr and some ioctls.

Changelog for v3:

- Eliminate btrfs_root->readonly, but check btrfs_root->root_item.flags.
- Rename BTRFS_ROOT_SNAP_RDONLY to BTRFS_ROOT_SUBVOL_RDONLY.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-23 08:49:17 +08:00
Li Zefan a6fa6fae40 btrfs: Add lzo compression support
Lzo is a much faster compression algorithm than gzib, so would allow
more users to enable transparent compression, and some users can
choose from compression ratio and speed for different applications

Usage:

 # mount -t btrfs -o compress[=<zlib,lzo>] dev /mnt
or
 # mount -t btrfs -o compress-force[=<zlib,lzo>] dev /mnt

"-o compress" without argument is still allowed for compatability.

Compatibility:

If we mount a filesystem with lzo compression, it will not be able be
mounted in old kernels. One reason is, otherwise btrfs will directly
dump compressed data, which sits in inline extent, to user.

Performance:

The test copied a linux source tarball (~400M) from an ext4 partition
to the btrfs partition, and then extracted it.

(time in second)
           lzo        zlib        nocompress
copy:      10.6       21.7        14.9
extract:   70.1       94.4        66.6

(data size in MB)
           lzo        zlib        nocompress
copy:      185.87     108.69      394.49
extract:   193.80     132.36      381.21

Changelog:

v1 -> v2:
- Select LZO_COMPRESS and LZO_DECOMPRESS in btrfs Kconfig.
- Add incompability flag.
- Fix error handling in compress code.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-22 23:15:47 +08:00
Li Zefan 261507a02c btrfs: Allow to add new compression algorithm
Make the code aware of compression type, instead of always assuming
zlib compression.

Also make the zlib workspace function as common code for all
compression types.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-22 23:15:45 +08:00
Mariusz Kozlowski 0410c94aff btrfs: make 1-bit signed fileds unsigned
Fixes these sparse warnings:
fs/btrfs/ctree.h:811:17: error: dubious one-bit signed bitfield
fs/btrfs/ctree.h:812:20: error: dubious one-bit signed bitfield
fs/btrfs/ctree.h:813:19: error: dubious one-bit signed bitfield

Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:07 -05:00
Sage Weil 4260f7c751 Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed
Add a mount option user_subvol_rm_allowed that allows users to delete a
(potentially non-empty!) subvol when they would otherwise we allowed to do
an rmdir(2).  We duplicate the may_delete() checks from the core VFS code
to implement identical security checks (minus the directory size check).
We additionally require that the user has write+exec permission on the
subvol root inode.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 21:42:10 -04:00
Sage Weil bb9c12c945 Btrfs: async transaction commit
Add support for an async transaction commit that is ordered such that any
subsequent operations will join the following transaction, but does not
wait until the current commit is fully on disk.  This avoids much of the
latency associated with the btrfs_commit_transaction for callers concerned
with serialization and not safety.

The wait_for_unblock flag controls whether we wait for the 'middle' portion
of commit_transaction to complete, which is necessary if the caller expects
some of the modifications contained in the commit to be available (this is
the case for subvol/snapshot creation).

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:37:34 -04:00
Chris Mason 6b5b817f10 Merge branch 'bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work
Conflicts:
	fs/btrfs/extent-tree.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 09:27:49 -04:00
Josef Bacik 88c2ba3b06 Btrfs: Add a clear_cache mount option
If something goes wrong with the free space cache we need a way to make sure
it's not loaded on mount and that it's cleared for everybody.  When you pass the
clear_cache option it will make it so all block groups are setup to be cleared,
which keeps them from being loaded and then they will be truncated when the
transaction is committed.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-29 09:26:36 -04:00
Josef Bacik 67377734fd Btrfs: add support for mixed data+metadata block groups
There are just a few things that need to be fixed in the kernel to support mixed
data+metadata block groups.  Mostly we just need to make sure that if we are
using mixed block groups that we continue to allocate mixed block groups as we
need them.  Also we need to make sure __find_space_info will find our space info
if we search for DATA or METADATA only.  Tested this with xfstests and it works
nicely.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-29 09:26:36 -04:00
Josef Bacik 0cb59c9953 Btrfs: write out free space cache
This is a simple bit, just dump the free space cache out to our preallocated
inode when we're writing out dirty block groups.  There are a bunch of changes
in inode.c in order to account for special cases.  Mostly when we're doing the
writeout we're holding trans_mutex, so we need to use the nolock transacation
functions.  Also we can't do asynchronous completions since the async thread
could be blocked on already completed IO waiting for the transaction lock.  This
has been tested with xfstests and btrfs filesystem balance, as well as my ENOSPC
tests.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-29 09:26:29 -04:00
Josef Bacik 0af3d00bad Btrfs: create special free space cache inode
In order to save free space cache, we need an inode to hold the data, and we
need a special item to point at the right inode for the right block group.  So
first, create a special item that will point to the right inode, and the number
of extent entries we will have and the number of bitmaps we will have.  We
truncate and pre-allocate space everytime to make sure it's uptodate.

This feature will be turned on as soon as you mount with -o space_cache, however
it is safe to boot into old kernels, they will just generate the cache the old
fashion way.  When you boot back into a newer kernel we will notice that we
modified and not the cache and automatically discard the cache.

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-28 15:59:09 -04:00
Josef Bacik 8bb8ab2e93 Btrfs: rework how we reserve metadata bytes
With multi-threaded writes we were getting ENOSPC early because somebody would
come in, start flushing delalloc because they couldn't make their reservation,
and in the meantime other threads would come in and use the space that was
getting freed up, so when the original thread went to check to see if they had
space they didn't and they'd return ENOSPC.  So instead if we have some free
space but not enough for our reservation, take the reservation and then start
doing the flushing.  The only time we don't take reservations is when we've
already overcommitted our space, that way we don't have people who come late to
the party way overcommitting ourselves.  This also moves all of the retrying and
flushing code into reserve_metdata_bytes so it's all uniform.  This keeps my
fs_mark test from returning -ENOSPC as soon as it starts and actually lets me
fill up the disk.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-22 15:55:01 -04:00
Josef Bacik 0019f10db6 Btrfs: re-work delalloc flushing
Currently we try and flush delalloc, but we only do that in a sort of weak way,
which works fine in most cases but if we're under heavy pressure we need to be
able to wait for flushing to happen.  Also instead of checking the bytes
reserved in the block_rsv, check the space info since it is more accurate.  The
sync option will be used in a future patch.

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-22 15:54:58 -04:00
Josef Bacik 89a55897a2 Btrfs: fix df regression
The new ENOSPC stuff breaks out the raid types which breaks the way we were
reporting df to the system.  This fixes it back so that Available is the total
space available to data and used is the actual bytes used by the filesystem.
This means that Available is Total - data used - all of the metadata space.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-22 15:54:55 -04:00
Al Viro 45321ac543 Make ->drop_inode() just return whether inode needs to be dropped
... and let iput_final() do the actual eviction or retention

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:35 -04:00
Al Viro bd55597520 convert btrfs to ->evict_inode()
NB: do we want btrfs_wait_ordered_range() on eviction of
inodes with positive i_nlink on subvolume with zero root_refs?
If not, btrfs_evict_inode() can be simplified by unconditionally
bailing out in case of i_nlink > 0 in the very beginning...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:22 -04:00
Christoph Hellwig 7ea8085910 drop unused dentry argument to ->fsync
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:05:02 -04:00
Josef Bacik 4b46fce233 Btrfs: add basic DIO read/write support
This provides basic DIO support for reading and writing.  It does not do the
work to recover from mismatching checksums, that will come later.  A few design
changes have been made from Jim's code (sorry Jim!)

1) Use the generic direct-io code.  Jim originally re-wrote all the generic DIO
code in order to account for all of BTRFS's oddities, but thanks to that work it
seems like the best bet is to just ignore compression and such and just opt to
fallback on buffered IO.

2) Fallback on buffered IO for compressed or inline extents.  Jim's code did
it's own buffering to make dio with compressed extents work.  Now we just
fallback onto normal buffered IO.

3) Use ordered extents for the writes so that all of the

lock_extent()
lookup_ordered()

type checks continue to work.

4) Do the lock_extent() lookup_ordered() loop in readpage so we don't race with
DIO writes.

I've tested this with fsx and everything works great.  This patch depends on my
dio and filemap.c patches to work.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:57 -04:00
Yan, Zheng 3fd0a5585e Btrfs: Metadata ENOSPC handling for balance
This patch adds metadata ENOSPC handling for the balance code.
It is consisted by following major changes:

1. Avoid COW tree leave in the phrase of merging tree.

2. Handle interaction with snapshot creation.

3. make the backref cache can live across transactions.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:54 -04:00
Yan, Zheng efa5646456 Btrfs: Pre-allocate space for data relocation
Pre-allocate space for data relocation. This can detect ENOPSC
condition caused by fragmentation of free space.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:53 -04:00
Yan, Zheng d68fc57b7e Btrfs: Metadata reservation for orphan inodes
reserve metadata space for handling orphan inodes

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:52 -04:00
Yan, Zheng 8929ecfa50 Btrfs: Introduce global metadata reservation
Reserve metadata space for extent tree, checksum tree and root tree

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:52 -04:00
Yan, Zheng 0ca1f7ceb1 Btrfs: Update metadata reservation for delayed allocation
Introduce metadata reservation context for delayed allocation
and update various related functions.

This patch also introduces EXTENT_FIRST_DELALLOC control bit for
set/clear_extent_bit. It tells set/clear_bit_hook whether they
are processing the first extent_state with EXTENT_DELALLOC bit
set. This change is important if set/clear_extent_bit involves
multiple extent_state.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:51 -04:00
Yan, Zheng a22285a6a3 Btrfs: Integrate metadata reservation with start_transaction
Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.

Changes since V1:

Add code that check if unlink and rmdir will free space.

Add ENOSPC handling for clone ioctl.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:50 -04:00
Yan, Zheng f0486c68e4 Btrfs: Introduce contexts for metadata reservation
Introducing metadata reseravtion contexts has two major advantages.
First, it makes metadata reseravtion more traceable. Second, it can
reclaim freed space and re-add them to the itself after transaction
committed.

Besides add btrfs_block_rsv structure and related helper functions,
This patch contains following changes:

Move code that decides if freed tree block should be pinned into
btrfs_free_tree_block().

Make space accounting more accurate, mainly for handling read only
block groups.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:50 -04:00
Yan, Zheng 5da9d01b66 Btrfs: Shrink delay allocated space in a synchronized
Shrink delayed allocation space in a synchronized manner is more
controllable than flushing all delay allocated space in an async
thread.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:48 -04:00
Yan, Zheng 424499dbd0 Btrfs: Kill allocate_wait in space_info
We already have fs_info->chunk_mutex to avoid concurrent
chunk creation.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:48 -04:00
Yan, Zheng b742bb82f1 Btrfs: Link block groups of different raid types
The size of reserved space is stored in space_info. If block groups
of different raid types are linked to separate space_info, changing
allocation profile will corrupt reserved space accounting.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:47 -04:00
Linus Torvalds 795d580bae Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: add check for changed leaves in setup_leaf_for_split
  Btrfs: create snapshot references in same commit as snapshot
  Btrfs: fix small race with delalloc flushing waitqueue's
  Btrfs: use add_to_page_cache_lru, use __page_cache_alloc
  Btrfs: fix chunk allocate size calculation
  Btrfs: kill max_extent mount option
  Btrfs: fail to mount if we have problems reading the block groups
  Btrfs: check btrfs_get_extent return for IS_ERR()
  Btrfs: handle kmalloc() failure in inode lookup ioctl
  Btrfs: dereferencing freed memory
  Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk()
  Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree()
  Btrfs: Remove unnecessary finish_wait() in wait_current_trans()
  Btrfs: add NULL check for do_walk_down()
  Btrfs: remove duplicate include in ioctl.c

Fix trivial conflict in fs/btrfs/compression.c due to slab.h include
cleanups.
2010-04-05 13:21:15 -07:00
Josef Bacik 287a0ab91d Btrfs: kill max_extent mount option
As Yan pointed out, theres not much reason for all this complicated math to
account for file extents being split up into max_extent chunks, since they are
likely to all end up in the same leaf anyway.  Since there isn't much reason to
use max_extent, just remove the option altogether so we have one less thing we
need to test.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30 21:19:09 -04:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Linus Torvalds 441f4058a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (30 commits)
  Btrfs: fix the inode ref searches done by btrfs_search_path_in_tree
  Btrfs: allow treeid==0 in the inode lookup ioctl
  Btrfs: return keys for large items to the search ioctl
  Btrfs: fix key checks and advance in the search ioctl
  Btrfs: buffer results in the space_info ioctl
  Btrfs: use __u64 types in ioctl.h
  Btrfs: fix search_ioctl key advance
  Btrfs: fix gfp flags masking in the compression code
  Btrfs: don't look at bio flags after submit_bio
  btrfs: using btrfs_stack_device_id() get devid
  btrfs: use memparse
  Btrfs: add a "df" ioctl for btrfs
  Btrfs: cache the extent state everywhere we possibly can V2
  Btrfs: cache ordered extent when completing io
  Btrfs: cache extent state in find_delalloc_range
  Btrfs: change the ordered tree to use a spinlock instead of a mutex
  Btrfs: finish read pages in the order they are submitted
  btrfs: fix btrfs_mkdir goto for no free objectids
  Btrfs: flush data on snapshot creation
  Btrfs: make df be a little bit more understandable
  ...
2010-03-18 16:50:55 -07:00
Akinobu Mita 91748467a5 btrfs: use memparse
Use memparse() instead of its own private implementation.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 11:00:14 -04:00
Josef Bacik 2ac55d41b5 Btrfs: cache the extent state everywhere we possibly can V2
This patch just goes through and fixes everybody that does

lock_extent()
blah
unlock_extent()

to use

lock_extent_bits()
blah
unlock_extent_cached()

and pass around a extent_state so we only have to do the searches once per
function.  This gives me about a 3 mb/s boots on my random write test.  I have
not converted some things, like the relocation and ioctl's, since they aren't
heavily used and the relocation stuff is in the middle of being re-written.  I
also changed the clear_extent_bit() to only unset the cached state if we are
clearing EXTENT_LOCKED and related stuff, so we can do things like this

lock_extent_bits()
clear delalloc bits
unlock_extent_cached()

without losing our cached state.  I tested this thoroughly and turned on
LEAK_DEBUG to make sure we weren't leaking extent states, everything worked out
fine.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 11:00:13 -04:00
Chris Mason 1e701a3292 Btrfs: add new defrag-range ioctl.
The btrfs defrag ioctl was limited to doing the entire file.  This
commit adds a new interface that can defrag a specific range inside
the file.

It can also force compression on the file, allowing you to selectively
compress individual files after they were created, even when mount -o
compress isn't turned on.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 11:00:10 -04:00
Josef Bacik 6ef5ed0d38 Btrfs: add ioctl and incompat flag to set the default mount subvol
This patch needs to go along with my previous patch.  This lets us set the
default dir item's location to whatever root we want to use as our default
mounting subvol.  With this we don't have to use mount -o subvol=<tree id>
anymore to mount a different subvol, we can just set the new one and it will
just magically work.  I've done some moderate testing with this, mostly just
switching the default mount around, mounting subvols and the default mount at
the same time and such, everything seems to work.  Thanks,

Older kernels would generally be able to still mount the filesystem with the
default subvolume set, but it would result in a different volume being mounted,
which could be an even more unpleasant suprise for users.  So if you set your
default subvolume, you can't go back to older kernels.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 11:00:08 -04:00
Josef Bacik 73f73415ca Btrfs: change how we mount subvolumes
This work is in preperation for being able to set a different root as the
default mounting root.

There is currently a problem with how we mount subvolumes.  We cannot currently
mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the
default subvolume.  So say you take a snapshot of the default subvolume and call
it snap1, and then take a snapshot of snap1 and call it snap2, so now you have

/
/snap1
/snap1/snap2

as your available volumes.  Currently you can only mount / and /snap1,
you cannot mount /snap1/snap2.  To fix this problem instead of passing
subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is
the tree id that gets spit out via the subvolume listing you get from
the subvolume listing patches (btrfs filesystem list).  This allows us
to mount /, /snap1 and /snap1/snap2 as the root volume.

In addition to the above, we also now read the default dir item in the
tree root to get the root key that it points to.  For now this just
points at what has always been the default subvolme, but later on I plan
to change it to point at whatever root you want to be the new default
root, so you can just set the default mount and not have to mount with
-o subvolid=<treeid>.  I tested this out with the above scenario and it
worked perfectly.  Thanks,

mount -o subvol operates inside the selected subvolid.  For example:

mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt

/mnt will have the snap1 directory for the subvolume with id
256.

mount -o subvol=snap /dev/xxx /mnt

/mnt will be the snap directory of whatever the default subvolume
is.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 10:58:13 -04:00
Josef Bacik 12534832cb Btrfs: make set/get functions for the super compat_ro flags use compat_ro
Our set/get functions for compat_ro_flags actually look at compat_flags.  This
will mess any attempt to use compat flags up.  The fix is obvious.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 10:55:10 -04:00
Christoph Hellwig a9185b41a4 pass writeback_control to ->write_inode
This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-05 13:25:52 -05:00
Chris Mason a555f810af Btrfs: Add mount -o compress-force
The default btrfs mount -o compress mode will quickly back off
compressing a file if it notices that compression does not reduce the
size of the data being written.  This can save considerable CPU because
all future writes to the file go through uncompressed.

But some files are both very large and have mixed data stored in
them.  In that case, we want to add the ability to always try
compressing data before writing it.

This commit adds mount -o compress-force.  A later commit will add
a new inode flag that does the same thing.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-28 16:18:15 -05:00
Yan, Zheng 86b9f2eca5 Btrfs: Fix per root used space accounting
The bytes_used field in root item was originally planned to
trace the amount of used data and tree blocks. But it never
worked right since we can't trace freeing of data accurately.
This patch changes it to only trace the amount of tree blocks.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17 12:33:35 -05:00
Yan, Zheng 24bbcf0442 Btrfs: Add delayed iput
iput() can trigger new transactions if we are dropping the
final reference, so calling it in btrfs_commit_transaction
may end up deadlock. This patch adds delayed iput to avoid
the issue.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17 12:33:35 -05:00
Yan, Zheng f34f57a3ab Btrfs: Pass transaction handle to security and ACL initialization functions
Pass transaction handle down to security and ACL initialization
functions, so we can avoid starting nested transactions

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17 12:33:34 -05:00
Yan, Zheng c71bf099ab Btrfs: Avoid orphan inodes cleanup while replaying log
We do log replay in a single transaction, so it's not good to do unbound
operations. This patch cleans up orphan inodes cleanup after replaying
the log. It also avoids doing other unbound operations such as truncating
a file during replaying log. These unbound operations are postponed to
the orphan inode cleanup stage.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17 12:33:33 -05:00
Yan, Zheng 920bbbfb05 Btrfs: Rewrite btrfs_drop_extents
Rewrite btrfs_drop_extents by using btrfs_duplicate_item, so we can
avoid calling lock_extent within transaction.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-15 21:24:52 -05:00
Yan, Zheng ad48fd7546 Btrfs: Add btrfs_duplicate_item
btrfs_duplicate_item duplicates item with new key, guaranteeing
the source item and the new items are in the same tree leaf and
contiguous. It allows us to split file extent in place, without
using lock_extent to prevent bookend extent race.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-15 21:24:25 -05:00
Linus Torvalds dcbeb0bec5 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: always pin metadata in discard mode
  Btrfs: enable discard support
  Btrfs: add -o discard option
  Btrfs: properly wait log writers during log sync
  Btrfs: fix possible ENOSPC problems with truncate
  Btrfs: fix btrfs acl #ifdef checks
  Btrfs: streamline tree-log btree block writeout
  Btrfs: avoid tree log commit when there are no changes
  Btrfs: only write one super copy during fsync
2009-10-15 15:06:37 -07:00
Christoph Hellwig e244a0aeb6 Btrfs: add -o discard option
Enable discard by default is not a good idea given the the trim speed
of SSD prototypes we've seen, and the carecteristics for many high-end
arrays.  Turn of discards by default and require the -o discard option
to enable them on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-14 10:32:49 -04:00
Chris Mason 0eda294dfc Btrfs: fix btrfs acl #ifdef checks
The btrfs acl code was #ifdefing for a define
that didn't exist.  This correctly matches it
to the values used by the Kconfig file.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13 13:51:39 -04:00
Chris Mason 257c62e1bc Btrfs: avoid tree log commit when there are no changes
rpm has a habit of running fdatasync when the file hasn't
changed.  We already detect if a file hasn't been changed
in the current transaction but it might have been sent to
the tree-log in this transaction and not changed since
the last call to fsync.

In this case, we want to avoid a tree log sync, which includes
a number of synchronous writes and barriers.  This commit
extends the existing tracking of the last transaction to change
a file to also track the last sub-transaction.

The end result is that rpm -ivh and -Uvh are roughly twice as fast,
and on par with ext3.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13 13:35:12 -04:00
Linus Torvalds 474a503d4b Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix file clone ioctl for bookend extents
  Btrfs: fix uninit compiler warning in cow_file_range_nocow
  Btrfs: constify dentry_operations
  Btrfs: optimize back reference update during btrfs_drop_snapshot
  Btrfs: remove negative dentry when deleting subvolumne
  Btrfs: optimize fsync for the single writer case
  Btrfs: async delalloc flushing under space pressure
  Btrfs: release delalloc reservations on extent item insertion
  Btrfs: delay clearing EXTENT_DELALLOC for compressed extents
  Btrfs: cleanup extent_clear_unlock_delalloc flags
  Btrfs: fix possible softlockup in the allocator
  Btrfs: fix deadlock on async thread startup
2009-10-11 11:23:13 -07:00
Alexey Dobriyan 82d339d9b3 Btrfs: constify dentry_operations
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09 09:54:36 -04:00
Josef Bacik ff782e0a13 Btrfs: optimize fsync for the single writer case
This patch optimizes the tree logging stuff so it doesn't always wait 1 jiffie
for new people to join the logging transaction if there is only ever 1 writer.
This helps a little bit with latency where we have something like RPM where it
will fdatasync every file it writes, and so waiting the 1 jiffie for every
fdatasync really starts to add up.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08 15:30:04 -04:00
Josef Bacik e3ccfa9897 Btrfs: async delalloc flushing under space pressure
This patch moves the delalloc flushing that occurs when we are under space
pressure off to a async thread pool.  This helps since we only free up
metadata space when we actually insert the extent item, which means it takes
quite a while for space to be free'ed up if we wait on all ordered extents.
However, if space is freed up due to inline extents being inserted, we can
wake people who are waiting up early, and they can finish their work.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08 15:21:23 -04:00
Josef Bacik 32c00aff71 Btrfs: release delalloc reservations on extent item insertion
This patch fixes an issue with the delalloc metadata space reservation
code.  The problem is we used to free the reservation as soon as we
allocated the delalloc region.  The problem with this is if we are not
inserting an inline extent, we don't actually insert the extent item until
after the ordered extent is written out.  This patch does 3 things,

1) It moves the reservation clearing stuff into the ordered code, so when
we remove the ordered extent we remove the reservation.
2) It adds a EXTENT_DO_ACCOUNTING flag that gets passed when we clear
delalloc bits in the cases where we want to clear the metadata reservation
when we clear the delalloc extent, in the case that we do an inline extent
or we invalidate the page.
3) It adds another waitqueue to the space info so that when we start a fs
wide delalloc flush, anybody else who also hits that area will simply wait
for the flush to finish and then try to make their allocation.

This has been tested thoroughly to make sure we did not regress on
performance.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08 15:21:10 -04:00
Chris Mason 61d92c328c Btrfs: fix deadlock on async thread startup
The btrfs async worker threads are used for a wide variety of things,
including processing bio end_io functions.  This means that when
the endio threads aren't running, the rest of the FS isn't
able to do the final processing required to clear PageWriteback.

The endio threads also try to exit as they become idle and
start more as the work piles up.  The problem is that starting more
threads means kthreadd may need to allocate ram, and that allocation
may wait until the global number of writeback pages on the system is
below a certain limit.

The result of that throttling is that end IO threads wait on
kthreadd, who is waiting on IO to end, which will never happen.

This commit fixes the deadlock by handing off thread startup to a
dedicated thread.  It also fixes a bug where the on-demand thread
creation was creating far too many threads because it didn't take into
account threads being started by other procs.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-05 09:44:45 -04:00
Linus Torvalds 0efe5e32c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix data space leak fix
  Btrfs: remove duplicates of filemap_ helpers
  Btrfs: take i_mutex before generic_write_checks
  Btrfs: fix arguments to btrfs_wait_on_page_writeback_range
  Btrfs: fix deadlock with free space handling and user transactions
  Btrfs: fix error cases for ioctl transactions
  Btrfs: Use CONFIG_BTRFS_POSIX_ACL to enable ACL code
  Btrfs: introduce missing kfree
  Btrfs: Fix setting umask when POSIX ACLs are not enabled
  Btrfs: proper -ENOSPC handling
2009-10-01 20:23:15 -07:00
Alexey Dobriyan 828c09509b const: constify remaining file_operations
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00
Chris Ball 3baf0bed0a Btrfs: Use CONFIG_BTRFS_POSIX_ACL to enable ACL code
We've already defined CONFIG_BTRFS_POSIX_ACL in Kconfig, but we're
currently not using it and are testing CONFIG_FS_POSIX_ACL instead.
CONFIG_FS_POSIX_ACL states "Never use this symbol for ifdefs".

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-29 13:51:05 -04:00
Josef Bacik 9ed74f2dba Btrfs: proper -ENOSPC handling
At the start of a transaction we do a btrfs_reserve_metadata_space() and
specify how many items we plan on modifying.  Then once we've done our
modifications and such, just call btrfs_unreserve_metadata_space() for
the same number of items we reserved.

For keeping track of metadata needed for data I've had to add an extent_io op
for when we merge extents.  This lets us track space properly when we are doing
sequential writes, so we don't end up reserving way more metadata space than
what we need.

The only place where the metadata space accounting is not done is in the
relocation code.  This is because Yan is going to be reworking that code in the
near future, so running btrfs-vol -b could still possibly result in a ENOSPC
related panic.  This patch also turns off the metadata_ratio stuff in order to
allow users to more efficiently use their disk space.

This patch makes it so we track how much metadata we need for an inode's
delayed allocation extents by tracking how many extents are currently
waiting for allocation.  It introduces two new callbacks for the
extent_io tree's, merge_extent_hook and split_extent_hook.  These help
us keep track of when we merge delalloc extents together and split them
up.  Reservations are handled prior to any actually dirty'ing occurs,
and then we unreserve after we dirty.

btrfs_unreserve_metadata_for_delalloc() will make the appropriate
unreservations as needed based on the number of reservations we
currently have and the number of extents we currently have.  Doing the
reservation outside of doing any of the actual dirty'ing lets us do
things like filemap_flush() the inode to try and force delalloc to
happen, or as a last resort actually start allocation on all delalloc
inodes in the fs.  This has survived dbench, fs_mark and an fsx torture
test.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-28 16:29:42 -04:00
Josef Bacik 1b2da372b0 Btrfs: account for space used by the super mirrors
As we get closer to proper -ENOSPC handling in btrfs, we need more accurate
space accounting for the space info's.  Currently we exclude the free space for
the super mirrors, but the space they take up isn't accounted for in any of the
counters.  This patch introduces bytes_super, which keeps track of the amount
of bytes used for a super mirror in the block group cache and space info.  This
makes sure that our free space caclucations will be completely accurate.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21 19:23:50 -04:00
Josef Bacik ba1bf4818b Btrfs: make balance code choose more wisely when relocating
Currently, we can panic the box if the first block group we go to move is of a
type where there is no space left to move those extents.  For example, if we
fill the disk up with data, and then we try to balance and we have no room to
move the data nor room to allocate new chunks, we will panic.  Change this by
checking to see if we have room to move this chunk around, and if not, return
-ENOSPC and move on to the next chunk.  This will make sure we remove block
groups that are moveable, like if we have alot of empty metadata block groups,
and then that way we make room to be able to balance our data chunks as well.
Tested this with an fs that would panic on btrfs-vol -b normally, but no longer
panics with this patch.

V1->V2:
-actually search for a free extent on the device to make sure we can allocate a
chunk if need be.

-fix btrfs_shrink_device to make sure we actually try to relocate all the
chunks, and then if we can't return -ENOSPC so if we are doing a btrfs-vol -r
we don't remove the device with data still on it.

-check to make sure the block group we are going to relocate isn't the last one
in that particular space

-fix a bug in btrfs_shrink_device where we would change the device's size and
not fix it if we fail to do our relocate

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21 19:23:48 -04:00
Yan, Zheng 76dda93c6a Btrfs: add snapshot/subvolume destroy ioctl
This patch adds snapshot/subvolume destroy ioctl.  A subvolume that isn't being
used and doesn't contains links to other subvolumes can be destroyed.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21 16:00:26 -04:00
Yan, Zheng 4df27c4d5c Btrfs: change how subvolumes are organized
btrfs allows subvolumes and snapshots anywhere in the directory tree.
If we snapshot a subvolume that contains a link to other subvolume
called subvolA, subvolA can be accessed through both the original
subvolume and the snapshot. This is similar to creating hard link to
directory, and has the very similar problems.

The aim of this patch is enforcing there is only one access point to
each subvolume. Only the first directory entry (the one added when
the subvolume/snapshot was created) is treated as valid access point.
The first directory entry is distinguished by checking root forward
reference. If the corresponding root forward reference is missing,
we know the entry is not the first one.

This patch also adds snapshot/subvolume rename support, the code
allows rename subvolume link across subvolumes.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21 15:56:00 -04:00
Yan, Zheng 13a8a7c8c4 Btrfs: do not reuse objectid of deleted snapshot/subvol
The new back reference format does not allow reusing objectid of
deleted snapshot/subvol. So we use ++highest_objectid to allocate
objectid for new snapshot/subvol.

Now we use ++highest_objectid to allocate objectid for both new inode
and new snapshot/subvolume, so this patch removes 'find hole' code in
btrfs_find_free_objectid.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21 15:56:00 -04:00
Yan Zheng 11833d66be Btrfs: improve async block group caching
This patch gets rid of two limitations of async block group caching.
The old code delays handling pinned extents when block group is in
caching. To allocate logged file extents, the old code need wait
until block group is fully cached. To get rid of the limitations,
This patch introduces a data structure to track the progress of
caching. Base on the caching progress, we know which extents should
be added to the free space cache when handling the pinned extents.
The logged file extents are also handled in a similar way.

This patch also changes how pinned extents are tracked. The old
code uses one tree to track pinned extents, and copy the pinned
extents tree at transaction commit time. This patch makes it use
two trees to track pinned extents. One tree for extents that are
pinned in the running transaction, one tree for extents that can
be unpinned. At transaction commit time, we swap the two trees.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-17 15:47:36 -04:00
Chris Mason 83ebade34b Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2009-09-11 19:07:25 -04:00
Chris Mason a1ed835e1a Btrfs: Fix extent replacment race
Data COW means that whenever we write to a file, we replace any old
extent pointers with new ones.  There was a window where a readpage
might find the old extent pointers on disk and cache them in the
extent_map tree in ram in the middle of a given write replacing them.

Even though both the readpage and the write had their respective bytes
in the file locked, the extent readpage inserts may cover more bytes than
it had locked down.

This commit closes the race by keeping the new extent pinned in the extent
map tree until after the on-disk btree is properly setup with the new
extent pointers.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11 13:31:07 -04:00
Linus Torvalds ec6a8679fa Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: be more polite in the async caching threads
  Btrfs: preserve commit_root for async caching
2009-07-30 16:46:48 -07:00
Yan Zheng 276e680d19 Btrfs: preserve commit_root for async caching
The async block group caching code uses the commit_root pointer
to get a stable version of the extent allocation tree for scanning.
This copy of the tree root isn't going to change and it significantly
reduces the complexity of the scanning code.

During a commit, we have a loop where we update the extent allocation
tree root.  We need to loop because updating the root pointer in
the tree of tree roots may allocate blocks which may change the
extent allocation tree.

Right now the commit_root pointer is changed inside this loop.  It
is more correct to change the commit_root pointer only after all the
looping is done.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-30 09:40:40 -04:00
Linus Torvalds 655c5d8fc1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (22 commits)
  Btrfs: Fix async caching interaction with unmount
  Btrfs: change how we unpin extents
  Btrfs: Correct redundant test in add_inode_ref
  Btrfs: find smallest available device extent during chunk allocation
  Btrfs: clear all space_info->full after removing a block group
  Btrfs: make flushoncommit mount option correctly wait on ordered_extents
  Btrfs: Avoid delayed reference update looping
  Btrfs: Fix ordering of key field checks in btrfs_previous_item
  Btrfs: find_free_dev_extent doesn't handle holes at the start of the device
  Btrfs: Remove code duplication in comp_keys
  Btrfs: async block group caching
  Btrfs: use hybrid extents+bitmap rb tree for free space
  Btrfs: Fix crash on read failures at mount
  Btrfs: remove of redundant btrfs_header_level
  Btrfs: adjust NULL test
  Btrfs: Remove broken sanity check from btrfs_rmap_block()
  Btrfs: convert nested spin_lock_irqsave to spin_lock
  Btrfs: make sure all dirty blocks are written at commit time
  Btrfs: fix locking issue in btrfs_find_next_key
  Btrfs: fix double increment of path->slots[0] in btrfs_next_leaf
  ...
2009-07-28 14:27:06 -07:00
Josef Bacik 68b38550dd Btrfs: change how we unpin extents
We are racy with async block caching and unpinning extents.  This patch makes
things much less complicated by only unpinning the extent if the block group is
cached.  We check the block_group->cached var under the block_group->lock spin
lock.  If it is set to BTRFS_CACHE_FINISHED then we update the pinned counters,
and unpin the extent and add the free space back.  If it is not set to this, we
start the caching of the block group so the next time we unpin extents we can
unpin the extent.  This keeps us from racing with the async caching threads,
lets us kill the fs wide async thread counter, and keeps us from having to set
DELALLOC bits for every extent we hit if there are caching kthreads going.

One thing that needed to be changed was btrfs_free_super_mirror_extents.  Now
instead of just looking for LOCKED extents, we also look for DIRTY extents,
since we could have left some extents pinned in the previous transaction that
will never get freed now that we are unmounting, which would cause us to leak
memory.  So btrfs_free_super_mirror_extents has been changed to
btrfs_free_pinned_extents, and it will clear the extents locked for the super
mirror, and any remaining pinned extents that may be present.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-27 13:57:01 -04:00
Josef Bacik 817d52f8db Btrfs: async block group caching
This patch moves the caching of the block group off to a kthread in order to
allow people to allocate sooner.  Instead of blocking up behind the caching
mutex, we instead kick of the caching kthread, and then attempt to make an
allocation.  If we cannot, we wait on the block groups caching waitqueue, which
the caching kthread will wake the waiting threads up everytime it finds 2 meg
worth of space, and then again when its finished caching.  This is how I tested
the speedup from this

mkfs the disk
mount the disk
fill the disk up with fs_mark
unmount the disk
mount the disk
time touch /mnt/foo

Without my changes this took 11 seconds on my box, with these changes it now
takes 1 second.

Another change thats been put in place is we lock the super mirror's in the
pinned extent map in order to keep us from adding that stuff as free space when
caching the block group.  This doesn't really change anything else as far as the
pinned extent map is concerned, since for actual pinned extents we use
EXTENT_DIRTY, but it does mean that when we unmount we have to go in and unlock
those extents to keep from leaking memory.

I've also added a check where when we are reading block groups from disk, if the
amount of space used == the size of the block group, we go ahead and mark the
block group as cached.  This drastically reduces the amount of time it takes to
cache the block groups.  Using the same test as above, except doing a dd to a
file and then unmounting, it used to take 33 seconds to umount, now it takes 3
seconds.

This version uses the commit_root in the caching kthread, and then keeps track
of how many async caching threads are running at any given time so if one of the
async threads is still running as we cross transactions we can wait until its
finished before handling the pinned extents.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24 09:23:39 -04:00
Josef Bacik 9630308170 Btrfs: use hybrid extents+bitmap rb tree for free space
Currently btrfs has a problem where it can use a ridiculous amount of RAM simply
tracking free space.  As free space gets fragmented, we end up with thousands of
entries on an rb-tree per block group, which usually spans 1 gig of area.  Since
we currently don't ever flush free space cache back to disk this gets to be a
bit unweildly on large fs's with lots of fragmentation.

This patch solves this problem by using PAGE_SIZE bitmaps for parts of the free
space cache.  Initially we calculate a threshold of extent entries we can
handle, which is however many extent entries we can cram into 16k of ram.  The
maximum amount of RAM that should ever be used to track 1 gigabyte of diskspace
will be 32k of RAM, which scales much better than we did before.

Once we pass the extent threshold, we start adding bitmaps and using those
instead for tracking the free space.  This patch also makes it so that any free
space thats less than 4 * sectorsize we go ahead and put into a bitmap.  This is
nice since we try and allocate out of the front of a block group, so if the
front of a block group is heavily fragmented and then has a huge chunk of free
space at the end, we go ahead and add the fragmented areas to bitmaps and use a
normal extent entry to track the big chunk at the back of the block group.

I've also taken the opportunity to revamp how we search for free space.
Previously we indexed free space via an offset indexed rb tree and a bytes
indexed rb tree.  I've dropped the bytes indexed rb tree and use only the offset
indexed rb tree.  This cuts the number of tree operations we were doing
previously down by half, and gives us a little bit of a better allocation
pattern since we will always start from a specific offset and search forward
from there, instead of searching for the size we need and try and get it as
close as possible to the offset we want.

I've given this a healthy amount of testing pre-new format stuff, as well as
post-new format stuff.  I've booted up my fedora box which is installed on btrfs
with this patch and ran with it for a few days without issues.  I've not seen
any performance regressions in any of my tests.

Since the last patch Yan Zheng fixed a problem where we could have overlapping
entries, so updating their offset inline would cause problems.  Thanks,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24 09:23:30 -04:00
Yan Zheng 1bec1aed1e Btrfs: fix definition of struct btrfs_extent_inline_ref
use __le64 instead of u64 in on-disk structure definition.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22 09:59:00 -04:00
Linus Torvalds 5291a12f05 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix error message formatting
  Btrfs: fix use after free in btrfs_start_workers fail path
  Btrfs: honor nodatacow/sum mount options for new files
  Btrfs: update backrefs while dropping snapshot
  Btrfs: account for space we may use in fallocate
  Btrfs: fix the file clone ioctl for preallocated extents
  Btrfs: don't log the inode in file_write while growing the file
2009-07-02 16:52:38 -07:00
Yan Zheng 2c47e605a9 Btrfs: update backrefs while dropping snapshot
The new backref format has restriction on type of backref item.  If a tree
block isn't referenced by its owner tree, full backrefs must be used for the
pointers in it. When a tree block loses its owner tree's reference, backrefs
for the pointers in it should be updated to full backrefs. Current
btrfs_drop_snapshot misses the code that updates backrefs, so it's unsafe for
general use.

This patch adds backrefs update code to btrfs_drop_snapshot.  It isn't a
problem in the restricted form btrfs_drop_snapshot is used today, but for
general snapshot deletion this update is required.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02 13:41:17 -04:00
Al Viro 5affd88a10 switch btrfs to inode->i_acl
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:17:05 -04:00
Al Viro 7df336ec12 Fix btrfs when ACLs are configured out
... otherwise generic_permission() will allow *anything* for all
files you don't own and that have some group permissions.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:36:43 -04:00
Christoph Hellwig 6cbff00f46 Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSION
Add support for the standard attributes set via chattr and read via
lsattr.  Currently we store the attributes in the flags value in
the btrfs inode, but I wonder whether we should split it into two so
that we don't have to keep converting between the two formats.

Remove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros
as they were confusing the existing code and got in the way of the
new additions.

Also add the FS_IOC_GETVERSION ioctl for getting i_generation as it's
trivial.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:29:52 -04:00
Chris Mason c289811cc0 Btrfs: autodetect SSD devices
During mount, btrfs will check the queue nonrot flag
for all the devices found in the FS.  If they are all
non-rotating, SSD mode is enabled by default.

If the FS was mounted with -o nossd, the non-rotating
flag is ignored.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:29:52 -04:00
Chris Mason 451d7585a8 Btrfs: add mount -o ssd_spread to spread allocations out
Some SSDs perform best when reusing block numbers often, while
others perform much better when clustering strictly allocates
big chunks of unused space.

The default mount -o ssd will find rough groupings of blocks
where there are a bunch of free blocks that might have some
allocated blocks mixed in.

mount -o ssd_spread will make sure there are no allocated blocks
mixed in.  It should perform better on lower end SSDs.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:29:52 -04:00
Yan Zheng 5d4f98a28c Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)
This commit introduces a new kind of back reference for btrfs metadata.
Once a filesystem has been mounted with this commit, IT WILL NO LONGER
BE MOUNTABLE BY OLDER KERNELS.

When a tree block in subvolume tree is cow'd, the reference counts of all
extents it points to are increased by one.  At transaction commit time,
the old root of the subvolume is recorded in a "dead root" data structure,
and the btree it points to is later walked, dropping reference counts
and freeing any blocks where the reference count goes to 0.

The increments done during cow and decrements done after commit cancel out,
and the walk is a very expensive way to go about freeing the blocks that
are no longer referenced by the new btree root.  This commit reduces the
transaction overhead by avoiding the need for dead root records.

When a non-shared tree block is cow'd, we free the old block at once, and the
new block inherits old block's references. When a tree block with reference
count > 1 is cow'd, we increase the reference counts of all extents
the new block points to by one, and decrease the old block's reference count by
one.

This dead tree avoidance code removes the need to modify the reference
counts of lower level extents when a non-shared tree block is cow'd.
But we still need to update back ref for all pointers in the block.
This is because the location of the block is recorded in the back ref
item.

We can solve this by introducing a new type of back ref. The new
back ref provides information about pointer's key, level and in which
tree the pointer lives. This information allow us to find the pointer
by searching the tree. The shortcoming of the new back ref is that it
only works for pointers in tree blocks referenced by their owner trees.

This is mostly a problem for snapshots, where resolving one of these
fuzzy back references would be O(number_of_snapshots) and quite slow.
The solution used here is to use the fuzzy back references in the common
case where a given tree block is only referenced by one root,
and use the full back references when multiple roots have a reference
on a given block.

This commit adds per subvolume red-black tree to keep trace of cached
inodes. The red-black tree helps the balancing code to find cached
inodes whose inode numbers within a given range.

This commit improves the balancing code by introducing several data
structures to keep the state of balancing. The most important one
is the back ref cache. It caches how the upper level tree blocks are
referenced. This greatly reduce the overhead of checking back ref.

The improved balancing code scales significantly better with a large
number of snapshots.

This is a very large commit and was written in a number of
pieces.  But, they depend heavily on the disk format change and were
squashed together to make sure git bisect didn't end up in a
bad state wrt space balancing or the format change.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:29:46 -04:00
Chris Mason e980b50cda Btrfs: fix fallocate deadlock on inode extent lock
The btrfs fallocate call takes an extent lock on the entire range
being fallocated, and then runs through insert_reserved_extent on each
extent as they are allocated.

The problem with this is that btrfs_drop_extents may decide to try
and take the same extent lock fallocate was already holding.  The solution
used here is to push down knowledge of the range that is already locked
going into btrfs_drop_extents.

It turns out that at least one other caller had the same bug.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:05 -04:00
Josef Bacik 97e728d435 Btrfs: try to keep a healthy ratio of metadata vs data block groups
This patch makes the chunk allocator keep a good ratio of metadata vs data
block groups.  By default for every 8 data block groups, we'll allocate 1
metadata chunk, or about 12% of the disk will be allocated for metadata.  This
can be changed by specifying the metadata_ratio mount option.

This is simply the number of data block groups that have to be allocated to
force a metadata chunk allocation.  By making sure we allocate metadata chunks
more often, we are less likely to get into situations where the whole disk
has been allocated as data block groups.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:02 -04:00
Linus Torvalds b983471794 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: BUG to BUG_ON changes
  Btrfs: remove dead code
  Btrfs: remove dead code
  Btrfs: fix typos in comments
  Btrfs: remove unused ftrace include
  Btrfs: fix __ucmpdi2 compile bug on 32 bit builds
  Btrfs: free inode struct when btrfs_new_inode fails
  Btrfs: fix race in worker_loop
  Btrfs: add flushoncommit mount option
  Btrfs: notreelog mount option
  Btrfs: introduce btrfs_show_options
  Btrfs: rework allocation clustering
  Btrfs: Optimize locking in btrfs_next_leaf()
  Btrfs: break up btrfs_search_slot into smaller pieces
  Btrfs: kill the pinned_mutex
  Btrfs: kill the block group alloc mutex
  Btrfs: clean up find_free_extent
  Btrfs: free space cache cleanups
  Btrfs: unplug in the async bio submission threads
  Btrfs: keep processing bios for a given bdev if our proc is batching
2009-04-03 15:14:44 -07:00
Wu Fengguang d4a789474a Btrfs: fix typos in comments
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Sage Weil dccae99995 Btrfs: add flushoncommit mount option
The 'flushoncommit' mount option forces any data dirtied by a write in a
prior transaction to commit as part of the current commit.  This makes
the committed state a fully consistent view of the file system from the
application's perspective (i.e., it includes all completed file system
operations).  This was previously the behavior only when a snapshot is
created.

This is used by Ceph to ensure that completed writes make it to the
platter along with the metadata operations they are bound to (by
BTRFS_IOC_TRANS_{START,END}).

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:59:01 -04:00
Sage Weil 3a5e14048a Btrfs: notreelog mount option
Add a 'notreelog' mount option to disable the tree log (used by fsync,
O_SYNC writes).  This is much slower, but the tree logging produces
inconsistent views into the FS for ceph.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:49:40 -04:00
Chris Mason fa9c0d795f Btrfs: rework allocation clustering
Because btrfs is copy-on-write, we end up picking new locations for
blocks very often.  This makes it fairly difficult to maintain perfect
read patterns over time, but we can at least do some optimizations
for writes.

This is done today by remembering the last place we allocated and
trying to find a free space hole big enough to hold more than just one
allocation.  The end result is that we tend to write sequentially to
the drive.

This happens all the time for metadata and it happens for data
when mounted -o ssd.  But, the way we record it is fairly racey
and it tends to fragment the free space over time because we are trying
to allocate fairly large areas at once.

This commit gets rid of the races by adding a free space cluster object
with dedicated locking to make sure that only one process at a time
is out replacing the cluster.

The free space fragmentation is somewhat solved by allowing a cluster
to be comprised of smaller free space extents.  This part definitely
adds some CPU time to the cluster allocations, but it allows the allocator
to consume the small holes left behind by cow.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 09:47:43 -04:00
Josef Bacik 04018de5d4 Btrfs: kill the pinned_mutex
This patch removes the pinned_mutex.  The extent io map has an internal tree
lock that protects the tree itself, and since we only copy the extent io map
when we are committing the transaction we don't need it there.  We also don't
need it when caching the block group since searching through the tree is also
protected by the internal map spin lock.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:18 -04:00
Josef Bacik 6226cb0a5e Btrfs: kill the block group alloc mutex
This patch removes the block group alloc mutex used to protect the free space
tree for allocations and replaces it with a spin lock which is used only to
protect the free space rb tree.  This means we only take the lock when we are
directly manipulating the tree, which makes us a touch faster with
multi-threaded workloads.

This patch also gets rid of btrfs_find_free_space and replaces it with
btrfs_find_space_for_alloc, which takes the number of bytes you want to
allocate, and empty_size, which is used to indicate how much free space should
be at the end of the allocation.

It will return an offset for the allocator to use.  If we don't end up using it
we _must_ call btrfs_add_free_space to put it back.  This is the tradeoff to
kill the alloc_mutex, since we need to make sure nobody else comes along and
takes our space.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:18 -04:00
Linus Torvalds c226fd659f Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: try to free metadata pages when we free btree blocks
  Btrfs: add extra flushing for renames and truncates
  Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod
  Btrfs: optimize fsyncs on old files
  Btrfs: tree logging unlink/rename fixes
  Btrfs: Make sure i_nlink doesn't hit zero too soon during log replay
  Btrfs: limit balancing work while flushing delayed refs
  Btrfs: readahead checksums during btrfs_finish_ordered_io
  Btrfs: leave btree locks spinning more often
  Btrfs: Only let very young transactions grow during commit
  Btrfs: Check for a blocking lock before taking the spin
  Btrfs: reduce stack in cow_file_range
  Btrfs: reduce stalls during transaction commit
  Btrfs: process the delayed reference queue in clusters
  Btrfs: try to cleanup delayed refs while freeing extents
  Btrfs: reduce stack usage in some crucial tree balancing functions
  Btrfs: do extent allocation and reference count updates in the background
  Btrfs: don't preallocate metadata blocks during btrfs_search_slot
2009-04-01 10:20:44 -07:00
Nick Piggin c2ec175c39 mm: page_mkwrite change prototype to match fault
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:14 -07:00
Chris Mason 5a3f23d515 Btrfs: add extra flushing for renames and truncates
Renames and truncates are both common ways to replace old data with new
data.  The filesystem can make an effort to make sure the new data is
on disk before actually replacing the old data.

This is especially important for rename, which many application use as
though it were atomic for both the data and the metadata involved.  The
current btrfs code will happily replace a file that is fully on disk
with one that was just created and still has pending IO.

If we crash after transaction commit but before the IO is done, we'll end
up replacing a good file with a zero length file.  The solution used
here is to create a list of inodes that need special ordering and force
them to disk before the commit is done.  This is similar to the
ext3 style data=ordering, except it is only done on selected files.

Btrfs is able to get away with this because it does not wait on commits
very often, even for fsync (which use a sub-commit).

For renames, we order the file when it wasn't already
on disk and when it is replacing an existing file.  Larger files
are sent to filemap_flush right away (before the transaction handle is
opened).

For truncates, we order if the file goes from non-zero size down to
zero size.  This is a little different, because at the time of the
truncate the file has no dirty bytes to order.  But, we flag the inode
so that it is added to the ordered list on close (via release method).  We
also immediately add it to the ordered list of the current transaction
so that we can try to flush down any writes the application sneaks in
before commit.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-31 14:27:58 -04:00
Chris Mason 12fcfd22fe Btrfs: tree logging unlink/rename fixes
The tree logging code allows individual files or directories to be logged
without including operations on other files and directories in the FS.
It tries to commit the minimal set of changes to disk in order to
fsync the single file or directory that was sent to fsync or O_SYNC.

The tree logging code was allowing files and directories to be unlinked
if they were part of a rename operation where only one directory
in the rename was in the fsync log.  This patch adds a few new rules
to the tree logging.

1) on rename or unlink, if the inode being unlinked isn't in the fsync
log, we must force a full commit before doing an fsync of the directory
where the unlink was done.  The commit isn't done during the unlink,
but it is forced the next time we try to log the parent directory.

Solution: record transid of last unlink/rename per directory when the
directory wasn't already logged.  For renames this is only done when
renaming to a different directory.

mkdir foo/some_dir
normal commit
rename foo/some_dir foo2/some_dir
mkdir foo/some_dir
fsync foo/some_dir/some_file

The fsync above will unlink the original some_dir without recording
it in its new location (foo2).  After a crash, some_dir will be gone
unless the fsync of some_file forces a full commit

2) we must log any new names for any file or dir that is in the fsync
log.  This way we make sure not to lose files that are unlinked during
the same transaction.

2a) we must log any new names for any file or dir during rename
when the directory they are being removed from was logged.

2a is actually the more important variant.  Without the extra logging
a crash might unlink the old name without recreating the new one

3) after a crash, we must go through any directories with a link count
of zero and redo the rm -rf

mkdir f1/foo
normal commit
rm -rf f1/foo
fsync(f1)

The directory f1 was fully removed from the FS, but fsync was never
called on f1, only its parent dir.  After a crash the rm -rf must
be replayed.  This must be able to recurse down the entire
directory tree.  The inode link count fixup code takes care of the
ugly details.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 16:14:52 -04:00
Chris Mason b9473439d3 Btrfs: leave btree locks spinning more often
btrfs_mark_buffer dirty would set dirty bits in the extent_io tree
for the buffers it was dirtying.  This may require a kmalloc and it
was not atomic.  So, anyone who called btrfs_mark_buffer_dirty had to
set any btree locks they were holding to blocking first.

This commit changes dirty tracking for extent buffers to just use a flag
in the extent buffer.  Now that we have one and only one extent buffer
per page, this can be safely done without losing dirty bits along the way.

This also introduces a path->leave_spinning flag that callers of
btrfs_search_slot can use to indicate they will properly deal with a
path returned where all the locks are spinning instead of blocking.

Many of the btree search callers now expect spinning paths,
resulting in better btree concurrency overall.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 16:14:28 -04:00
Chris Mason c3e69d58e8 Btrfs: process the delayed reference queue in clusters
The delayed reference queue maintains pending operations that need to
be done to the extent allocation tree.  These are processed by
finding records in the tree that are not currently being processed one at
a time.

This is slow because it uses lots of time searching through the rbtree
and because it creates lock contention on the extent allocation tree
when lots of different procs are running delayed refs at the same time.

This commit changes things to grab a cluster of refs for processing,
using a cursor into the rbtree as the starting point of the next search.
This way we walk smoothly through the rbtree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 16:14:26 -04:00
Chris Mason 56bec294de Btrfs: do extent allocation and reference count updates in the background
The extent allocation tree maintains a reference count and full
back reference information for every extent allocated in the
filesystem.  For subvolume and snapshot trees, every time
a block goes through COW, the new copy of the block adds a reference
on every block it points to.

If a btree node points to 150 leaves, then the COW code needs to go
and add backrefs on 150 different extents, which might be spread all
over the extent allocation tree.

These updates currently happen during btrfs_cow_block, and most COWs
happen during btrfs_search_slot.  btrfs_search_slot has locks held
on both the parent and the node we are COWing, and so we really want
to avoid IO during the COW if we can.

This commit adds an rbtree of pending reference count updates and extent
allocations.  The tree is ordered by byte number of the extent and byte number
of the parent for the back reference.  The tree allows us to:

1) Modify back references in something close to disk order, reducing seeks
2) Significantly reduce the number of modifications made as block pointers
are balanced around
3) Do all of the extent insertion and back reference modifications outside
of the performance critical btrfs_search_slot code.

#3 has the added benefit of greatly reducing the btrfs stack footprint.
The extent allocation tree modifications are done without the deep
(and somewhat recursive) call chains used in the past.

These delayed back reference updates must be done before the transaction
commits, and so the rbtree is tied to the transaction.  Throttling is
implemented to help keep the queue of backrefs at a reasonable size.

Since there was a similar mechanism in place for the extent tree
extents, that is removed and replaced by the delayed reference tree.

Yan Zheng <yan.zheng@oracle.com> helped review and fixup this code.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 16:14:25 -04:00
Chris Mason 9fa8cfe706 Btrfs: don't preallocate metadata blocks during btrfs_search_slot
In order to avoid doing expensive extent management with tree locks held,
btrfs_search_slot will preallocate tree blocks for use by COW without
any tree locks held.

A later commit moves all of the extent allocation work for COW into
a delayed update mechanism, and this preallocation will no longer be
required.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 16:14:25 -04:00
Chris Mason 4184ea7f90 Btrfs: Fix locking around adding new space_info
Storage allocated to different raid levels in btrfs is tracked by
a btrfs_space_info structure, and all of the current space_infos are
collected into a list_head.

Most filesystems have 3 or 4 of these structs total, and the list is
only changed when new raid levels are added or at unmount time.

This commit adds rcu locking on the list head, and properly frees
things at unmount time.  It also clears the space_info->full flag
whenever new space is added to the FS.

The locking for the space info list goes like this:

reads: protected by rcu_read_lock()
writes: protected by the chunk_mutex

At unmount time we don't need special locking because all the readers
are gone.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10 12:39:20 -04:00
Josef Bacik 6a63209fc0 Btrfs: add better -ENOSPC handling
This is a step in the direction of better -ENOSPC handling.  Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.

If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC.  This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.

bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line. 

bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point.  When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter.  This keeps us from
not actually being able to allocate space for any delalloc bytes.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-02-20 11:00:09 -05:00
Chris Mason 4008c04a07 Btrfs: make a lockdep class for the extent buffer locks
Btrfs is currently using spin_lock_nested with a nested value based
on the tree depth of the block.  But, this doesn't quite work because
the max tree depth is bigger than what spin_lock_nested can deal with,
and because locks are sometimes taken before the level field is filled in.

The solution here is to use lockdep_set_class_and_name instead, and to
set the class before unlocking the pages when the block is read from the
disk and just after init of a freshly allocated tree block.

btrfs_clear_path_blocking is also changed to take the locks in the proper
order, and it also makes sure all the locks currently held are properly
set to blocking before it tries to retake the spinlocks.  Otherwise, lockdep
gets upset about bad lock orderin.

The lockdep magic cam from Peter Zijlstra <peterz@infradead.org>

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12 14:09:45 -05:00
Jeff Mahoney e00f730865 Btrfs: remove btrfs_init_path
btrfs_init_path was initially used when the path objects were on the
stack.  Now all the work is done by btrfs_alloc_path and btrfs_init_path
isn't required.

This patch removes it, and just uses kmem_cache_zalloc to zero out the object.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12 14:11:25 -05:00
Chris Mason b4ce94de9b Btrfs: Change btree locking to use explicit blocking points
Most of the btrfs metadata operations can be protected by a spinlock,
but some operations still need to schedule.

So far, btrfs has been using a mutex along with a trylock loop,
most of the time it is able to avoid going for the full mutex, so
the trylock loop is a big performance gain.

This commit is step one for getting rid of the blocking locks entirely.
btrfs_tree_lock takes a spinlock, and the code explicitly switches
to a blocking lock when it starts an operation that can schedule.

We'll be able get rid of the blocking locks in smaller pieces over time.
Tracing allows us to find the most common cause of blocking, so we
can start with the hot spots first.

The basic idea is:

btrfs_tree_lock() returns with the spin lock held

btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in
the extent buffer flags, and then drops the spin lock.  The buffer is
still considered locked by all of the btrfs code.

If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops
the spin lock and waits on a wait queue for the blocking bit to go away.

Much of the code that needs to set the blocking bit finishes without actually
blocking a good percentage of the time.  So, an adaptive spin is still
used against the blocking bit to avoid very high context switch rates.

btrfs_clear_lock_blocking() clears the blocking bit and returns
with the spinlock held again.

btrfs_tree_unlock() can be called on either blocking or spinning locks,
it does the right thing based on the blocking bit.

ctree.c has a helper function to set/clear all the locked buffers in a
path as blocking.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04 09:25:08 -05:00
Chris Mason c487685d7c Btrfs: hash_lock is no longer needed
Before metadata is written to disk, it is updated to reflect that writeout
has begun.  Once this update is done, the block must be cow'd before it
can be modified again.

This update was originally synchronized by using a per-fs spinlock.  Today
the buffers for the metadata blocks are locked before writeout begins,
and everyone that tests the flag has the buffer locked as well.

So, the per-fs spinlock (called hash_lock for no good reason) is no
longer required.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04 09:24:25 -05:00
Yan Zheng 7237f18336 Btrfs: fix tree logs parallel sync
To improve performance, btrfs_sync_log merges tree log sync
requests. But it wrongly merges sync requests for different
tree logs. If multiple tree logs are synced at the same time,
only one of them actually gets synced.

This patch has following changes to fix the bug:

Move most tree log related fields in btrfs_fs_info to
btrfs_root. This allows merging sync requests separately
for each tree log.

Don't insert root item into the log root tree immediately
after log tree is allocated. Root item for log tree is
inserted when log tree get synced for the first time. This
allows syncing the log root tree without first syncing all
log trees.

At tree-log sync, btrfs_sync_log first sync the log tree;
then updates corresponding root item in the log root tree;
sync the log root tree; then update the super block.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-01-21 12:54:03 -05:00
Jan Engelhardt 95029d7d59 Btrfs: change/remove typedef
Change one typedef to a regular enum, and remove an unused one.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21 10:49:16 -05:00
Chris Mason d397712bcc Btrfs: Fix checkpatch.pl warnings
There were many, most are fixed now.  struct-funcs.c generates some warnings
but these are bogus.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05 21:25:51 -05:00
Chris Mason cad321ad52 Btrfs: shift all end_io work to thread pools
bio_end_io for reads without checksumming on and btree writes were
happening without using async thread pools.  This means the extent_io.c
code had to use spin_lock_irq and friends on the rb tree locks for
extent state.

There were some irq safe vs unsafe lock inversions between the delallock
lock and the extent state locks.  This patch gets rid of them by moving
all end_io code into the thread pools.

To avoid contention and deadlocks between the data end_io processing and the
metadata end_io processing yet another thread pool is added to finish
off metadata writes.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-17 14:51:42 -05:00
Yan Zheng 17d217fe97 Btrfs: fix nodatasum handling in balancing code
Checksums on data can be disabled by mount option, so it's
possible some data extents don't have checksums or have
invalid checksums. This causes trouble for data relocation.
This patch contains following things to make data relocation
work.

1) make nodatasum/nodatacow mount option only affects new
files. Checksums and COW on data are only controlled by the
inode flags.

2) check the existence of checksum in the nodatacow checker.
If checksums exist, force COW the data extent. This ensure that
checksum for a given block is either valid or does not exist.

3) update data relocation code to properly handle the case
of checksum missing.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-12 10:03:38 -05:00
Yan Zheng d2fb3437e4 Btrfs: fix leaking block group on balance
The block group structs are referenced in many different
places, and it's not safe to free while balancing.  So, those block
group structs were simply leaked instead.

This patch replaces the block group pointer in the inode with the starting byte
offset of the block group and adds reference counting to the block group
struct.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-11 16:30:39 -05:00
Chris Mason 459931eca5 Btrfs: Delete csum items when freeing extents
This finishes off the new checksumming code by removing csum items
for extents that are no longer in use.

The trick is doing it without racing because a single csum item may
hold csums for more than one extent.  Extra checks are added to
btrfs_csum_file_blocks to make sure that we are using the correct
csum item after dropping locks.

A new btrfs_split_item is added to split a single csum item so it
can be split without dropping the leaf lock.  This is used to
remove csum bytes from the middle of an item.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-10 09:10:46 -05:00
Chris Mason c3027eb552 Btrfs: Add inode sequence number for NFS and reserved space in a few structs
This adds a sequence number to the btrfs inode that is increased on
every update.  NFS will be able to use that to detect when an inode has
changed, without relying on inaccurate time fields.

While we're here, this also:

Puts reserved space into the super block and inode

Adds a log root transid to the super so we can pick the newest super
based on the fsync log as well as the main transaction ID.  For now
the log root transid is always zero, but that'll get fixed.

Adds a starting offset to the dev_item.  This will let us do better
alignment calculations if we know the start of a partition on the disk.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 16:40:21 -05:00
Chris Mason d20f7043fa Btrfs: move data checksumming into a dedicated tree
Btrfs stores checksums for each data block.  Until now, they have
been stored in the subvolume trees, indexed by the inode that is
referencing the data block.  This means that when we read the inode,
we've probably read in at least some checksums as well.

But, this has a few problems:

* The checksums are indexed by logical offset in the file.  When
compression is on, this means we have to do the expensive checksumming
on the uncompressed data.  It would be faster if we could checksum
the compressed data instead.

* If we implement encryption, we'll be checksumming the plain text and
storing that on disk.  This is significantly less secure.

* For either compression or encryption, we have to get the plain text
back before we can verify the checksum as correct.  This makes the raid
layer balancing and extent moving much more expensive.

* It makes the front end caching code more complex, as we have touch
the subvolume and inodes as we cache extents.

* There is potentitally one copy of the checksum in each subvolume
referencing an extent.

The solution used here is to store the extent checksums in a dedicated
tree.  This allows us to index the checksums by phyiscal extent
start and length.  It means:

* The checksum is against the data stored on disk, after any compression
or encryption is done.

* The checksum is stored in a central location, and can be verified without
following back references, or reading inodes.

This makes compression significantly faster by reducing the amount of
data that needs to be checksummed.  It will also allow much faster
raid management code in general.

The checksums are indexed by a key with a fixed objectid (a magic value
in ctree.h) and offset set to the starting byte of the extent.  This
allows us to copy the checksum items into the fsync log tree directly (or
any other tree), without having to invent a second format for them.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 16:58:54 -05:00
Chris Mason 2a7108ad89 Btrfs: rev the disk format for the inode compat and csum selection changes
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-02 09:58:02 -05:00
Josef Bacik 607d432da0 Btrfs: add support for multiple csum algorithms
This patch gives us the space we will need in order to have different csum
algorithims at some point in the future.  We save the csum algorithim type
in the superblock, and use those instead of define's.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-12-02 07:17:45 -05:00
Josef Bacik f2b636e80d Btrfs: add support for compat flags to btrfs
This adds the necessary disk format for handling compatibility flags
in the future to handle disk format changes.  We have a compat_flags,
compat_ro_flags and incompat_flags set for the super block.  Compat
flags will be to hold the features that are compatible with older
versions of btrfs, compat_ro flags have features that are compatible
with older versions of btrfs if the fs is mounted read only, and
incompat_flags has features that are incompatible with older versions
of btrfs.  This also axes the compat_flags field for the inode and
just makes the flags field a 64bit field, and changes the root item
flags field to 64bit.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-12-02 06:36:08 -05:00
Josef Bacik ea6a478ed9 Btrfs: Fix for lockdep warnings with alloc_mutex and pinned_mutex
This the lockdep complaint by having a different mutex to gaurd caching the
block group, so you don't end up with this backwards dependancy.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-11-20 12:16:16 -05:00
Chris Mason 73e9f5beb1 Btrfs: Update the disk format for the seed device and new root code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-18 11:50:33 -05:00
Chris Mason ea9e8b11bd Btrfs: prevent loops in the directory tree when creating snapshots
For a directory tree:

/mnt/subvolA/subvolB

btrfsctl -s /mnt/subvolA/subvolB /mnt

Will create a directory loop with subvolA under subvolB.  This
commit uses the forward refs for each subvol and snapshot to error out
before creating the loop.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17 21:14:24 -05:00
Chris Mason 0660b5af3f Btrfs: Add backrefs and forward refs for subvols and snapshots
Subvols and snapshots can now be referenced from any point in the directory
tree.  We need to maintain back refs for them so we can find lost
subvols.

Forward refs are added so that we know all of the subvols and
snapshots referenced anywhere in the directory tree of a single subvol.  This
can be used to do recursive snapshotting (but they aren't yet) and it is
also used to detect and prevent directory loops when creating new snapshots.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17 20:37:39 -05:00
Chris Mason 3394e1607e Btrfs: Give each subvol and snapshot their own anonymous devid
Each subvolume has its own private inode number space, and so we need
to fill in different device numbers for each subvolume to avoid confusing
applications.

This commit puts a struct super_block into struct btrfs_root so it can
call set_anon_super() and get a different device number generated for
each root.

btrfs_rename is changed to prevent renames across subvols.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17 20:42:26 -05:00
Chris Mason 3de4586c52 Btrfs: Allow subvolumes and snapshots anywhere in the directory tree
Before, all snapshots and subvolumes lived in a single flat directory.  This
was awkward and confusing because the single flat directory was only writable
with the ioctls.

This commit changes the ioctls to create subvols and snapshots at any
point in the directory tree.  This requires making separate ioctls for
snapshot and subvol creation instead of a combining them into one.

The subvol ioctl does:

btrfsctl -S subvol_name parent_dir

After the ioctl is done subvol_name lives inside parent_dir.

The snapshot ioctl does:

btrfsctl -s path_for_snapshot root_to_snapshot

path_for_snapshot can be an absolute or relative path.  btrfsctl breaks it up
into directory and basename components.

root_to_snapshot can be any file or directory in the FS.  The snapshot
is taken of the entire root where that file lives.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17 21:02:50 -05:00
Yan Zheng 2b82032c34 Btrfs: Seed device support
Seed device is a special btrfs with SEEDING super flag
set and can only be mounted in read-only mode. Seed
devices allow people to create new btrfs on top of it.

The new FS contains the same contents as the seed device,
but it can be mounted in read-write mode.

This patch does the following:

1) split code in btrfs_alloc_chunk into two parts. The first part does makes
the newly allocated chunk usable, but does not do any operation that modifies
the chunk tree. The second part does the the chunk tree modifications. This
division is for the bootstrap step of adding storage to the seed device.

2) Update device management code to handle seed device.
The basic idea is: For an FS grown from seed devices, its
seed devices are put into a list. Seed devices are
opened on demand at mounting time. If any seed device is
missing or has been changed, btrfs kernel module will
refuse to mount the FS.

3) make btrfs_find_block_group not return NULL when all
block groups are read-only.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-17 21:11:30 -05:00
Yan Zheng c146afad2c Btrfs: mount ro and remount support
This patch adds mount ro and remount support. The main
changes in patch are: adding btrfs_remount and related
helper function; splitting the transaction related code
out of close_ctree into btrfs_commit_super; updating
allocator to properly handle read only block group.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-12 14:34:12 -05:00
Josef Bacik f3465ca44e Btrfs: batch extent inserts/updates/deletions on the extent root
While profiling the allocator I noticed a good amount of time was being spent in
finish_current_insert and del_pending_extents, and as the filesystem filled up
more and more time was being spent in those functions.  This patch aims to try
and reduce that problem.  This happens two ways

1) track if we tried to delete an extent that we are going to update or insert.
Once we get into finish_current_insert we discard any of the extents that were
marked for deletion.  This saves us from doing unnecessary work almost every
time finish_current_insert runs.

2) Batch insertion/updates/deletions.  Instead of doing a btrfs_search_slot for
each individual extent and doing the needed operation, we instead keep the leaf
around and see if there is anything else we can do on that leaf.  On the insert
case I introduced a btrfs_insert_some_items, which will take an array of keys
with an array of data_sizes and try and squeeze in as many of those keys as
possible, and then return how many keys it was able to insert.  In the update
case we search for an extent ref, update the ref and then loop through the leaf
to see if any of the other refs we are looking to update are on that leaf, and
then once we are done we release the path and search for the next ref we need to
update.  And finally for the deletion we try and delete the extent+ref in pairs,
so we will try to find extent+ref pairs next to the extent we are trying to free
and free them in bulk if possible.

This along with the other cluster fix that Chris pushed out a bit ago helps make
the allocator preform more uniformly as it fills up the disk.  There is still a
slight drop as we fill up the disk since we start having to stick new blocks in
odd places which results in more COW's than on a empty fs, but the drop is not
nearly as severe as it was before.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-11-12 14:19:50 -05:00
Chris Mason 771ed689d2 Btrfs: Optimize compressed writeback and reads
When reading compressed extents, try to put pages into the page cache
for any pages covered by the compressed extent that readpages didn't already
preload.

Add an async work queue to handle transformations at delayed allocation processing
time.  Right now this is just compression.  The workflow is:

1) Find offsets in the file marked for delayed allocation
2) Lock the pages
3) Lock the state bits
4) Call the async delalloc code

The async delalloc code clears the state lock bits and delalloc bits.  It is
important this happens before the range goes into the work queue because
otherwise it might deadlock with other work queue items that try to lock
those extent bits.

The file pages are compressed, and if the compression doesn't work the
pages are written back directly.

An ordered work queue is used to make sure the inodes are written in the same
order that pdflush or writepages sent them down.

This changes extent_write_cache_pages to let the writepage function
update the wbc nr_written count.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-06 22:02:51 -05:00
Chris Mason 537fb06715 Btrfs: rev the disk format for fallocate
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-31 12:54:14 -04:00
Yan Zheng d899e05215 Btrfs: Add fallocate support v2
This patch updates btrfs-progs for fallocate support.

fallocate is a little different in Btrfs because we need to tell the
COW system that a given preallocated extent doesn't need to be
cow'd as long as there are no snapshots of it.  This leverages the
-o nodatacow checks.
 
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30 14:25:28 -04:00
Yan Zheng 80ff385665 Btrfs: update nodatacow code v2
This patch simplifies the nodatacow checker. If all references
were created after the latest snapshot, then we can avoid COW
safely. This patch also updates run_delalloc_nocow to do more
fine-grained checking.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30 14:20:02 -04:00
Yan Zheng 9036c10208 Btrfs: update hole handling v2
This patch splits the hole insertion code out of btrfs_setattr
into btrfs_cont_expand and updates btrfs_get_extent to properly
handle the case that file extent items are not continuous.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30 14:19:41 -04:00
Chris Mason 09fde3c9ba Btrfs: Rev the disk format for compression and root pointer generation fields 2008-10-29 14:49:04 -04:00
Yan Zheng 84234f3a1f Btrfs: Add root tree pointer transaction ids
This patch adds transaction IDs to root tree pointers.
Transaction IDs in tree pointers are compared with the
generation numbers in block headers when reading root
blocks of trees. This can detect some types of IO errors.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-29 14:49:05 -04:00
Josef Bacik 2517920135 Btrfs: nuke fs wide allocation mutex V2
This patch removes the giant fs_info->alloc_mutex and replaces it with a bunch
of little locks.

There is now a pinned_mutex, which is used when messing with the pinned_extents
extent io tree, and the extent_ins_mutex which is used with the pending_del and
extent_ins extent io trees.

The locking for the extent tree stuff was inspired by a patch that Yan Zheng
wrote to fix a race condition, I cleaned it up some and changed the locking
around a little bit, but the idea remains the same.  Basically instead of
holding the extent_ins_mutex throughout the processing of an extent on the
extent_ins or pending_del trees, we just hold it while we're searching and when
we clear the bits on those trees, and lock the extent for the duration of the
operations on the extent.

Also to keep from getting hung up waiting to lock an extent, I've added a
try_lock_extent so if we cannot lock the extent, move on to the next one in the
tree and we'll come back to that one.  I have tested this heavily and it does
not appear to break anything.  This has to be applied on top of my
find_free_extent redo patch.

I tested this patch on top of Yan's space reblancing code and it worked fine.
The only thing that has changed since the last version is I pulled out all my
debugging stuff, apparently I forgot to run guilt refresh before I sent the
last patch out.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-10-29 14:49:05 -04:00
Josef Bacik 80eb234af0 Btrfs: fix enospc when there is plenty of space
So there is an odd case where we can possibly return -ENOSPC when there is in
fact space to be had.  It only happens with Metadata writes, and happens _very_
infrequently.  What has to happen is we have to allocate have allocated out of
the first logical byte on the disk, which would set last_alloc to
first_logical_byte(root, 0), so search_start == orig_search_start.  We then
need to allocate for normal metadata, so BTRFS_BLOCK_GROUP_METADATA |
BTRFS_BLOCK_GROUP_DUP.  We will do a block lookup for the given search_start,
block_group_bits() won't match and we'll go to choose another block group.
However because search_start matches orig_search_start we go to see if we can
allocate a chunk.

If we are in the situation that we cannot allocate a chunk, we fail and ENOSPC.
This is kind of a big flaw of the way find_free_extent works, as it along with
find_free_space loop through _all_ of the block groups, not just the ones that
we want to allocate out of.  This patch completely kills find_free_space and
rolls it into find_free_extent.  I've introduced a sort of state machine into
this, which will make it easier to get cache miss information out of the
allocator, and will work well with my locking changes.

The basic flow is this:  We have the variable loop which is 0, meaning we are
in the hint phase.  We lookup the block group for the hint, and lookup the
space_info for what we want to allocate out of.  If the block group we were
pointed at by the hint either isn't of the correct type, or just doesn't have
the space we need, we set head to space_info->block_groups, so we start at the
beginning of the block groups for this particular space info, and loop through.

This is also where we add the empty_cluster to total_needed.  At this point
loop is set to 1 and we just loop through all of the block groups for this
particular space_info looking for the space we need, just as find_free_space
would have done, except we only hit the block groups we want and not _all_ of
the block groups.  If we come full circle we see if we can allocate a chunk.
If we cannot of course we exit with -ENOSPC and we are good.  If not we start
over at space_info->block_groups and loop through again, with loop == 2.  If we
come full circle and haven't found what we need then we exit with -ENOSPC.
I've been running this for a couple of days now and it seems stable, and I
haven't yet hit a -ENOSPC when there was plenty of space left.

Also I've made a groups_sem to handle the group list for the space_info.  This
is part of my locking changes, but is relatively safe and seems better than
holding the space_info spinlock over that entire search time.  Thanks,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-10-29 14:49:05 -04:00
Yan Zheng f82d02d9d8 Btrfs: Improve space balancing code
This patch improves the space balancing code to keep more sharing
of tree blocks. The only case that breaks sharing of tree blocks is
data extents get fragmented during balancing. The main changes in
this patch are:

Add a 'drop sub-tree' function. This solves the problem in old code
that BTRFS_HEADER_FLAG_WRITTEN check breaks sharing of tree block.

Remove relocation mapping tree. Relocation mappings are stored in
struct btrfs_ref_path and updated dynamically during walking up/down
the reference path. This reduces CPU usage and simplifies code.

This patch also fixes a bug. Root items for reloc trees should be
updated in btrfs_free_reloc_root.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-29 14:49:05 -04:00
Chris Mason c8b978188c Btrfs: Add zlib compression support
This is a large change for adding compression on reading and writing,
both for inline and regular extents.  It does some fairly large
surgery to the writeback paths.

Compression is off by default and enabled by mount -o compress.  Even
when the -o compress mount option is not used, it is possible to read
compressed extents off the disk.

If compression for a given set of pages fails to make them smaller, the
file is flagged to avoid future compression attempts later.

* While finding delalloc extents, the pages are locked before being sent down
to the delalloc handler.  This allows the delalloc handler to do complex things
such as cleaning the pages, marking them writeback and starting IO on their
behalf.

* Inline extents are inserted at delalloc time now.  This allows us to compress
the data before inserting the inline extent, and it allows us to insert
an inline extent that spans multiple pages.

* All of the in-memory extent representations (extent_map.c, ordered-data.c etc)
are changed to record both an in-memory size and an on disk size, as well
as a flag for compression.

From a disk format point of view, the extent pointers in the file are changed
to record the on disk size of a given extent and some encoding flags.
Space in the disk format is allocated for compression encoding, as well
as encryption and a generic 'other' field.  Neither the encryption or the
'other' field are currently used.

In order to limit the amount of data read for a single random read in the
file, the size of a compressed extent is limited to 128k.  This is a
software only limit, the disk format supports u64 sized compressed extents.

In order to limit the ram consumed while processing extents, the uncompressed
size of a compressed extent is limited to 256k.  This is a software only limit
and will be subject to tuning later.

Checksumming is still done on compressed extents, and it is done on the
uncompressed version of the data.  This way additional encodings can be
layered on without having to figure out which encoding to checksum.

Compression happens at delalloc time, which is basically singled threaded because
it is usually done by a single pdflush thread.  This makes it tricky to
spread the compression load across all the cpus on the box.  We'll have to
look at parallel pdflush walks of dirty inodes at a later time.

Decompression is hooked into readpages and it does spread across CPUs nicely.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
Christoph Hellwig cb8e70901d Btrfs: Fix subvolume creation locking rules
Creating a subvolume is in many ways like a normal VFS ->mkdir, and we
really need to play with the VFS topology locking rules.  So instead of
just creating the snapshot on disk and then later getting rid of
confliting aliases do it correctly from the start.  This will become
especially important once we allow for subvolumes anywhere in the tree,
and not just below a hidden root.

Note that snapshots will need the same treatment, but do to the delay
in creating them we can't do it currently.  Chris promised to fix that
issue, so I'll wait on that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-10-09 13:39:39 -04:00
Chris Mason 833023e46c Btrfs: Rev the disk format for the new back reference format
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-09 11:55:03 -04:00
Yan Zheng 3bb1a1bc42 Btrfs: Remove offset field from struct btrfs_extent_ref
The offset field in struct btrfs_extent_ref records the position
inside file that file extent is referenced by. In the new back
reference system, tree leaves holding references to file extent
are recorded explicitly. We can scan these tree leaves very quickly, so the
offset field is not required.

This patch also makes the back reference system check the objectid
when extents are in deleting.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-09 11:46:24 -04:00
Yan Zheng a76a3cd40c Btrfs: Count space allocated to file in bytes
This patch makes btrfs count space allocated to file in bytes instead
of 512 byte sectors.

Everything else in btrfs uses a byte count instead of sector sizes or
blocks sizes, so this fits better.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-09 11:46:29 -04:00
Chris Mason 30c43e2444 Btrfs: remove last_log_alloc allocator optimization
The tree logging code was trying to separate tree log allocations
from normal metadata allocations to improve writeback patterns during
an fsync.

But, the code was not effective and ended up just mixing tree log
blocks with regular metadata.  That seems to be working fairly well,
so the last_log_alloc code can be removed.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-03 12:24:01 -04:00
Chris Mason 323ac95bce Btrfs: don't read leaf blocks containing only checksums during truncate
Checksum items take up a significant portion of the metadata for large files.
It is possible to avoid reading them during truncates by checking the keys in
the higher level nodes.

If a given leaf is followed by another leaf where the lowest key is a checksum
item from the same file, we know we can safely delete the leaf without
reading it.

For a 32GB file on a 6 drive raid0 array, Btrfs needs 8s to delete
the file with a cold cache.  It is read bound during the run.

With this change, Btrfs is able to delete the file in 0.5s

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-01 19:05:46 -04:00
Chris Mason d352ac6814 Btrfs: add and improve comments
This improves the comments at the top of many functions.  It didn't
dive into the guts of functions because I was trying to
avoid merging problems with the new allocator and back reference work.

extent-tree.c and volumes.c were both skipped, and there is definitely
more work todo in cleaning and commenting the code.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-29 15:18:18 -04:00
Chris Mason 8c8bee1d7c Btrfs: Wait for IO on the block device inodes of newly added devices
btrfs-vol -a /dev/xxx will zero the first and last two MB of the device.
The kernel code needs to wait for this IO to finish before it adds
the device.

btrfs metadata IO does not happen through the block device inode.  A
separate address space is used, allowing the zero filled buffer heads in
the block device inode to be written to disk after FS metadata starts
going down to the disk via the btrfs metadata inode.

The end result is zero filled metadata blocks after adding new devices
into the filesystem.

The fix is a simple filemap_write_and_wait on the block device inode
before actually inserting it into the pool of available devices.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-29 11:19:10 -04:00
Zheng Yan 1a40e23b95 Btrfs: update space balancing code
This patch updates the space balancing code to utilize the new
backref format.  Before, btrfs-vol -b would break any COW links
on data blocks or metadata.  This was slow and caused the amount
of space used to explode if a large number of snapshots were present.

The new code can keeps the sharing of all data extents and
most of the tree blocks.

To maintain the sharing of data extents, the space balance code uses
a seperate inode hold data extent pointers, then updates the references
to point to the new location.

To maintain the sharing of tree blocks, the space balance code uses
reloc trees to relocate tree blocks in reference counted roots.
There is one reloc tree for each subvol, and all reloc trees share
same root key objectid. Reloc trees are snapshots of the latest
committed roots of subvols (root->commit_root).

To relocate a tree block referenced by a subvol, there are two steps.
COW the block through subvol's reloc tree, then update block pointer in
the subvol to point to the new block. Since all reloc trees share
same root key objectid, doing special handing for tree blocks
owned by them is easy. Once a tree block has been COWed in one
reloc tree, we can use the resulting new block directly when the
same block is required to COW again through other reloc trees.
In this way, relocated tree blocks are shared between reloc trees,
so they are also shared between subvols.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-26 10:09:34 -04:00
Zheng Yan 5b21f2ed3f Btrfs: extent_map and data=ordered fixes for space balancing
* Add an EXTENT_BOUNDARY state bit to keep the writepage code
from merging data extents that are in the process of being
relocated.  This allows us to do accounting for them properly.

* The balancing code relocates data extents indepdent of the underlying
inode.  The extent_map code was modified to properly account for
things moving around (invalidating extent_map caches in the inode).

* Don't take the drop_mutex in the create_subvol ioctl.  It isn't
required.

* Fix walking of the ordered extent list to avoid races with sys_unlink

* Change the lock ordering rules.  Transaction start goes outside
the drop_mutex.  This allows btrfs_commit_transaction to directly
drop the relocation trees.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-26 10:05:38 -04:00
Zheng Yan e465768938 Btrfs: Add shared reference cache
Btrfs has a cache of reference counts in leaves, allowing it to
avoid reading tree leaves while deleting snapshots.  To reduce
contention with multiple subvolumes, this cache is private to each
subvolume.

This patch adds shared reference cache support. The new space
balancing code plays with multiple subvols at the same time, So
the old per-subvol reference cache is not well suited.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-26 10:04:53 -04:00
Zheng Yan e856981384 Btrfs: allocator fixes for space balancing update
* Reserved extent accounting:  reserved extents have been
allocated in the rbtrees that track free space but have not
been allocated on disk.  They were never properly accounted for
in the past, making it hard to know how much space was really free.

* btrfs_find_block_group used to return NULL for block groups that
had been removed by the space balancing code.  This made it hard
to account for space during the final stages of a balance run.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-26 10:05:48 -04:00
Chris Mason 2b1f55b0f0 Remove Btrfs compat code for older kernels
Btrfs had compatibility code for kernels back to 2.6.18.  These have
been removed, and will be maintained in a separate backport
git tree from now on.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 15:41:59 -04:00
Zheng Yan 31840ae1a6 Btrfs: Full back reference support
This patch makes the back reference system to explicit record the
location of parent node for all types of extents. The location of
parent node is placed into the offset field of backref key. Every
time a tree block is balanced, the back references for the affected
lower level extents are updated.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Josef Bacik 0f9dd46cda Btrfs: free space accounting redo
1) replace the per fs_info extent_io_tree that tracked free space with two
rb-trees per block group to track free space areas via offset and size.  The
reason to do this is because most allocations come with a hint byte where to
start, so we can usually find a chunk of free space at that hint byte to satisfy
the allocation and get good space packing.  If we cannot find free space at or
after the given offset we fall back on looking for a chunk of the given size as
close to that given offset as possible.  When we fall back on the size search we
also try to find a slot as close to the size we want as possible, to avoid
breaking small chunks off of huge areas if possible.

2) remove the extent_io_tree that tracked the block group cache from fs_info and
replaced it with an rb-tree thats tracks block group cache via offset.  also
added a per space_info list that tracks the block group cache for the particular
space so we can lookup related block groups easily.

3) cleaned up the allocation code to make it a little easier to read and a
little less complicated.  Basically there are 3 steps, first look from our
provided hint.  If we couldn't find from that given hint, start back at our
original search start and look for space from there.  If that fails try to
allocate space if we can and start looking again.  If not we're screwed and need
to start over again.

4) small fixes.  there were some issues in volumes.c where we wouldn't allocate
the rest of the disk.  fixed cow_file_range to actually pass the alloc_hint,
which has helped a good bit in making the fs_mark test I run have semi-normal
results as we run out of space.  Generally with data allocations we don't track
where we last allocated from, so everytime we did a data allocation we'd search
through every block group that we have looking for free space.  Now searching a
block group with no free space isn't terribly time consuming, it was causing a
slight degradation as we got more data block groups.  The alloc_hint has fixed
this slight degredation and made things semi-normal.

There is still one nagging problem I'm working on where we will get ENOSPC when
there is definitely plenty of space.  This only happens with metadata
allocations, and only when we are almost full.  So you generally hit the 85%
mark first, but sometimes you'll hit the BUG before you hit the 85% wall.  I'm
still tracking it down, but until then this seems to be pretty stable and make a
significant performance gain.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Chris Mason d0c803c404 Btrfs: Record dirty pages tree-log pages in an extent_io tree
This is the same way the transaction code makes sure that all the
other tree blocks are safely on disk.  There's an extent_io tree
for each root, and any blocks allocated to the tree logs are
recorded in that tree.

At tree-log sync, the extent_io tree is walked to flush down the
dirty pages and wait for them.

The main benefit is less time spent walking the tree log and skipping
clean pages, and getting sequential IO down to the drive.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Zheng Yan 6527cdbe68 Btrfs: Update find free objectid function for orphan cleanup code
Orphan items use BTRFS_ORPHAN_OBJECTID (-5UUL) as key objectid. This
affects the find free objectid functions, inode objectid can easily
overflow after orphan file cleanup.

---

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Christoph Hellwig a237d2a2bd remove unused function btrfs_ilookup
btrfs_ilookup is unused, which is good because a normal filesystem
should never have to use ilookup anyway.  Remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Chris Mason 91c0827de2 Btrfs: Rev the disk format
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Chris Mason e02119d5a7 Btrfs: Add a write ahead tree log to optimize synchronous operations
File syncs and directory syncs are optimized by copying their
items into a special (copy-on-write) log tree.  There is one log tree per
subvolume and the btrfs super block points to a tree of log tree roots.

After a crash, items are copied out of the log tree and back into the
subvolume.  See tree-log.c for all the details.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:07 -04:00
Chris Mason f3f9931e3d Btrfs: Rev the disk format
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Balaji Rao 1a54ef8c11 Introduce btrfs_iget helper
Date: Mon, 21 Jul 2008 02:01:04 +0530
This patch introduces a btrfs_iget helper to be used in NFS support.

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason 4854ddd0ed Btrfs: Wait for kernel threads to make progress during async submission
Before this change, btrfs would use a bdi congestion function to make
sure there weren't too many pending async checksum work items.

This change makes the process creating async work items wait instead,
leading to fewer congestion returns from the bdi.  This improves
pdflush background_writeout scanning.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason 0986fe9eac Btrfs: Count async bios separately from async checksum work items
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Eric Sandeen 5036f53868 Btrfs: fix RHEL test for ClearPageFsMisc
Newer RHEL5 kernels define both ClearPageFSMisc and
ClearPageChecked, so test for both before redefining.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Yan Zheng 7ea394f119 Btrfs: Fix nodatacow for the new data=ordered mode
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason ea8c281947 Btrfs: Maintain a list of inodes that are delalloc and a way to wait on them
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Sage Weil 9ca9ee09c1 Btrfs: fix ioctl-initiated transactions vs wait_current_trans()
Commit 597:466b27332893 (btrfs_start_transaction: wait for commits in
progress) breaks the transaction start/stop ioctls by making
btrfs_start_transaction conditionally wait for the next transaction to
start.  If an application artificially is holding a transaction open,
things deadlock.

This workaround maintains a count of open ioctl-initiated transactions in
fs_info, and avoids wait_current_trans() if any are currently open (in
start_transaction() and btrfs_throttle()).  The start transaction ioctl
uses a new btrfs_start_ioctl_transaction() that _does_ call
wait_current_trans(), effectively pushing the join/wait decision to the
outer ioctl-initiated transaction.

This more or less neuters btrfs_throttle() when ioctl-initiated
transactions are in use, but that seems like a pretty fundamental
consequence of wrapping lots of write()'s in a transaction.  Btrfs has no
way to tell if the application considers a given operation as part of it's
transaction.

Obviously, if the transaction start/stop ioctls aren't being used, there
is no effect on current behavior.

Signed-off-by: Sage Weil <sage@newdream.net>
---
 ctree.h       |    1 +
 ioctl.c       |   12 +++++++++++-
 transaction.c |   18 +++++++++++++-----
 transaction.h |    2 ++
 4 files changed, 27 insertions(+), 6 deletions(-)

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason 65b51a009e btrfs_search_slot: reduce lock contention by cowing in two stages
A btree block cow has two parts, the first is to allocate a destination
block and the second is to copy the old bock over.

The first part needs locks in the extent allocation tree, and may need to
do IO.  This changeset splits that into a separate function that can be
called without any tree locks held.

btrfs_search_slot is changed to drop its path and start over if it has
to COW a contended block.  This often means that many writers will
pre-alloc a new destination for a the same contended block, but they
cache their prealloc for later use on lower levels in the tree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason 61b4944018 Btrfs: Fix streaming read performance with checksumming on
Large streaming reads make for large bios, which means each entry on the
list async work queues represents a large amount of data.  IO
congestion throttling on the device was kicking in before the async
worker threads decided a single thread was busy and needed some help.

The end result was that a streaming read would result in a single CPU
running at 100% instead of balancing the work off to other CPUs.

This patch also changes the pre-IO checksum lookup done by reads to
work on a per-bio basis instead of a per-page.  This results in many
extra btree lookups on large streaming reads.  Doing the checksum lookup
right before bio submit allows us to reuse searches while processing
adjacent offsets.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Yan bcc63abbf3 Btrfs: implement memory reclaim for leaf reference cache
The memory reclaiming issue happens when snapshot exists. In that
case, some cache entries may not be used during old snapshot dropping,
so they will remain in the cache until umount.

The patch adds a field to struct btrfs_leaf_ref to record create time. Besides,
the patch makes all dead roots of a given snapshot linked together in order of
create time. After a old snapshot was completely dropped, we check the dead
root list and remove all cache entries created before the oldest dead root in
the list.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Yan Zheng f321e49103 Btrfs: Update and fix mount -o nodatacow
To check whether a given file extent is referenced by multiple snapshots, the
checker walks down the fs tree through dead root and checks all tree blocks in
the path.

We can easily detect whether a given tree block is directly referenced by other
snapshot. We can also detect any indirect reference from other snapshot by
checking reference's generation. The checker can always detect multiple
references, but can't reliably detect cases of single reference. So btrfs may
do file data cow even there is only one reference.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason ab78c84de1 Btrfs: Throttle operations if the reference cache gets too large
A large reference cache is directly related to a lot of work pending
for the cleaner thread.  This throttles back new operations based on
the size of the reference cache so the cleaner thread will be able to keep
up.

Overall, this actually makes the FS faster because the cleaner thread will
be more likely to find things in cache.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 017e5369eb Btrfs: Leaf reference cache update
This changes the reference cache to make a single cache per root
instead of one cache per transaction, and to key by the byte number
of the disk block instead of the keys inside.

This makes it much less likely to have cache misses if a snapshot
or something has an extra reference on a higher node or a leaf while
the first transaction that added the leaf into the cache is dropping.

Some throttling is added to functions that free blocks heavily so they
wait for old transactions to drop.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Yan Zheng 31153d8128 Btrfs: Add a leaf reference cache
Much of the IO done while dropping snapshots is done looking up
leaves in the filesystem trees to see if they point to any extents and
to drop the references on any extents found.

This creates a cache so that IO isn't required.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 3a115f520f Btrfs: Rev the disk format magic
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Josef Bacik 7b12876623 Btrfs: Create orphan inode records to prevent lost files after a crash
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Josef Bacik 33268eaf0b Btrfs: Add ACL support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Josef Bacik 6099afe88f Btrfs: Remove unused xattr code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Josef Bacik aec7477b3b Btrfs: Implement new dir index format
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 3eaa288527 Btrfs: Fix the defragmention code and the block relocation code for data=ordered
Before setting an extent to delalloc, the code needs to wait for
pending ordered extents.

Also, the relocation code needs to wait for ordered IO before scanning
the block group again.  This is because the extents are not removed
until the IO for the new extents is finished

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 4881ee5a2e Btrfs: Fix some build problems on 2.6.18 based enterprise kernels
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason c286ac48ed Btrfs: alloc_mutex latency reduction
This releases the alloc_mutex in a few places that hold it for over long
operations.  btrfs_lookup_block_group is changed so that it doesn't need
the mutex at all.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 6dddcbeb28 Btrfs: Use mutex_lock_nested for tree locking
Lockdep has the notion of locking subclasses so that you can identify
locks you expect to be taken after other locks of the same class.  This
changes the per-extent buffer btree locking routines to use a subclass based
on the level in the tree.

Unfortunately, lockdep can only handle 8 total subclasses, and the btrfs
max level is also 8.  So when lockdep is on, use a lower max level.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason f421950f86 Btrfs: Fix some data=ordered related data corruptions
Stress testing was showing data checksum errors, most of which were caused
by a lookup bug in the extent_map tree.  The tree was caching the last
pointer returned, and searches would check the last pointer first.

But, search callers also expect the search to return the very first
matching extent in the range, which wasn't always true with the last
pointer usage.

For now, the code to cache the last return value is just removed.  It is
easy to fix, but I think lookups are rare enough that it isn't required anymore.

This commit also replaces do_sync_mapping_range with a local copy of the
related functions.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason 3edf7d33f4 Btrfs: Handle data checksumming on bios that span multiple ordered extents
Data checksumming is done right before the bio is sent down the IO stack,
which means a single bio might span more than one ordered extent.  In
this case, the checksumming data is split between two ordered extents.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason f929574938 btrfs_start_transaction: wait for commits in progress to finish
btrfs_commit_transaction has to loop waiting for any writers in the
transaction to finish before it can proceed.  btrfs_start_transaction
should be polite and not join a transaction that is in the process
of being finished off.

There are a few places that can't wait, basically the ones doing IO that
might be needed to finish the transaction.  For them, btrfs_join_transaction
is added.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00
Chris Mason 247e743cbe Btrfs: Use async helpers to deal with pages that have been improperly dirtied
Higher layers sometimes call set_page_dirty without asking the filesystem
to help.  This causes many problems for the data=ordered and cow code.
This commit detects pages that haven't been properly setup for IO and
kicks off an async helper to deal with them.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00
Chris Mason e6dcd2dc9c Btrfs: New data=ordered implementation
The old data=ordered code would force commit to wait until
all the data extents from the transaction were fully on disk.  This
introduced large latencies into the commit and stalled new writers
in the transaction for a long time.

The new code changes the way data allocations and extents work:

* When delayed allocation is filled, data extents are reserved, and
  the extent bit EXTENT_ORDERED is set on the entire range of the extent.
  A struct btrfs_ordered_extent is allocated an inserted into a per-inode
  rbtree to track the pending extents.

* As each page is written EXTENT_ORDERED is cleared on the bytes corresponding
  to that page.

* When all of the bytes corresponding to a single struct btrfs_ordered_extent
  are written, The previously reserved extent is inserted into the FS
  btree and into the extent allocation trees.  The checksums for the file
  data are also updated.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00
Chris Mason 7d9eb12c87 Btrfs: Add locking around volume management (device add/remove/balance)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00
Chris Mason 3f157a2fd2 Btrfs: Online btree defragmentation fixes
The btree defragger wasn't making forward progress because the new key wasn't
being saved by the btrfs_search_forward function.

This also disables the automatic btree defrag, it wasn't scaling well to
huge filesystems.  The auto-defrag needs to be done differently.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00
Chris Mason e7a84565bc Btrfs: Add btree locking to the tree defragmentation code
The online btree defragger is simplified and rewritten to use
standard btree searches instead of a walk up / down mechanism.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason a74a4b97b6 Btrfs: Replace the transaction work queue with kthreads
This creates one kthread for commits and one kthread for
deleting old snapshots.  All the work queues are removed.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 5cd57b2cbb Btrfs: Add a skip_locking parameter to struct path, and make various funcs honor it
Allocations may need to read in block groups from the extent allocation tree,
which will require a tree search and take locks on the extent allocation
tree.  But, those locks might already be held in other places, leading
to deadlocks.

Since the alloc_mutex serializes everything right now, it is safe to
skip the btree locking while caching block groups.  A better fix will be
to either create a recursive lock or find a way to back off existing
locks while caching block groups.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 051e1b9f74 Drop locks in btrfs_search_slot when reading a tree block.
One lock per btree block can make for significant congestion if everyone
has to wait for IO at the high levels of the btree.  This drops
locks held by a path when doing reads during a tree search.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason a213501153 Btrfs: Replace the big fs_mutex with a collection of other locks
Extent alloctions are still protected by a large alloc_mutex.
Objectid allocations are covered by a objectid mutex
Other btree operations are protected by a lock on individual btree nodes

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 925baeddc5 Btrfs: Start btree concurrency work.
The allocation trees and the chunk trees are serialized via their own
dedicated mutexes.  This means allocation location is still not very
fine grained.

The main FS btree is protected by locks on each block in the btree.  Locks
are taken top / down, and as processing finishes on a given level of the
tree, the lock is released after locking the lower level.

The end result of a search is now a path where only the lowest level
is locked.  Releasing or freeing the path drops any locks held.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 1cc127b5d1 Btrfs: Add a thread pool just for submit_bio
If a bio submission is after a lock holder waiting for the bio
on the work queue, it is possible to deadlock.  Move the bios
into their own pool.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Christoph Hellwig f46b5a66b3 Btrfs: split out ioctl.c
Split the ioctl handling out of inode.c into a file of it's own.
Also fix up checkpatch.pl warnings for the moved code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 4543df7ecc Btrfs: Add a mount option to control worker thread pool size
mount -o thread_pool_size changes the default, which is
min(num_cpus + 2, 8).  Larger thread pools would make more sense on
very large disk arrays.

This mount option controls the max size of each thread pool.  There
are multiple thread pools, so the total worker count will be larger
than the mount option.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 8b71284292 Btrfs: Add async worker threads for pre and post IO checksumming
Btrfs has been using workqueues to spread the checksumming load across
other CPUs in the system.  But, workqueues only schedule work on the
same CPU that queued the work, giving them a limited benefit for systems with
higher CPU counts.

This code adds a generic facility to schedule work with pools of kthreads,
and changes the bio submission code to queue bios up.  The queueing is
important to make sure large numbers of procs on the system don't
turn streaming workloads into random workloads by sending IO down
concurrently.

The end result of all of this is much higher performance (and CPU usage) when
doing checksumming on large machines.  Two worker pools are created,
one for writes and one for endio processing.  The two could deadlock if
we tried to service both from a single pool.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Christoph Hellwig edf24abe51 btrfs: sanity mount option parsing and early mount code
Also adds lots of comments to describe what's going on here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Sage Weil 6bf13c0cc8 Btrfs: transaction ioctls
These ioctls let a user application hold a transaction open while it
performs a series of operations.  A final ioctl does a sync on the fs
(closing the current transaction).  This is the main requirement for
Ceph's OSD to be able to keep the data it's storing in a btrfs volume
consistent, and AFAICS it works just fine.  The application would do
something like

	fd = ::open("some/file", O_RDONLY);
	::ioctl(fd, BTRFS_IOC_TRANS_START);
	/* do a bunch of stuff */
	::ioctl(fd, BTRFS_IOC_TRANS_END);
or just
	::close(fd);

And to ensure it commits to disk,

	::ioctl(fd, BTRFS_IOC_SYNC);

When a transaction is held open, the trans_handle is attached to the
struct file (via private_data) so that it will get cleaned up if the
process dies unexpectedly.  A held transaction is also ended on fsync() to
avoid a deadlock.

A misbehaving application could also deliberately hold a transaction open,
effectively locking up the FS, so it may make sense to restrict something
like this to root or something.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Sven Wegener 3b96362cc8 Btrfs: Invalidate dcache entry after creating snapshot and
We need to invalidate an existing dcache entry after creating a new
snapshot or subvolume, because a negative dache entry will stop us from
accessing the new snapshot or subvolume.

---
  ctree.h       |   23 +++++++++++++++++++++++
  inode.c       |    4 ++++
  transaction.c |    4 ++++
  3 files changed, 31 insertions(+)

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason 0ef3e66b67 Btrfs: Allocator fix variety pack
* Force chunk allocation when find_free_extent has to do a full scan
* Record the max key at the start of defrag so it doesn't run forever
* Block groups might not be contiguous, make a forward search for the
  next block group in extent-tree.c
* Get rid of extra checks for total fs size
* Fix relocate_one_reference to avoid relocating the same file data block
  twice when referenced by an older transaction
* Use the open device count when allocating chunks so that we don't
  try to allocate from devices that don't exist

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason cb03c743c6 Btrfs: Change the congestion functions to meter the number of async submits as well
The async submit workqueue was absorbing too many requests, leading to long
stalls where the async submitters were stalling.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason dfe2502068 Btrfs: Add mount -o degraded to allow mounts to continue with missing devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason a68d5933a0 Btrfs: Update nodatacow mode to support cloned single files and resizing
Before, nodatacow only checked to make sure multiple roots didn't have
references on a single extent.  This check makes sure that multiple
inodes don't have references.

nodatacow needed an extra check to see if the block group was currently
readonly.  This way cows forced by the chunk relocation code are honored.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason bf4ef67924 Btrfs: Properly find the root for snapshotted blocks during chunk relocation
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason a061fc8da7 Btrfs: Add support for online device removal
This required a few structural changes to the code that manages bdev pointers:

The VFS super block now gets an anon-bdev instead of a pointer to the
lowest bdev.  This allows us to avoid swapping the super block bdev pointer
around at run time.

The code to read in the super block no longer goes through the extent
buffer interface.  Things got ugly keeping the mapping constant.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Sage Weil f2eb0a241f Btrfs: Clone file data ioctl
Add a new ioctl to clone file data

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason ec44a35cbe Btrfs: Add balance ioctl to restripe the chunks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason 788f20eb5a Btrfs: Add new ioctl to add devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason 8f18cf1339 Btrfs: Make the resizer work based on shrinking and growing devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason 7ae9c09d8f Btrfs: Add support for labels in the super block
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason a443755f1c Btrfs: Check device uuids along with devids
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason e015640f9c Btrfs: Write bio checksumming outside the FS mutex
This significantly improves streaming write performance by allowing
concurrency in the data checksumming.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 44b8bd7edd Btrfs: Create a work queue for bio writes
This allows checksumming to happen in parallel among many cpus, and
keeps us from bogging down pdflush with the checksumming code.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 321aecc656 Btrfs: Add RAID10 support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason e17cade25f Btrfs: Add chunk uuids and update multi-device back references
Block headers now store the chunk tree uuid

Chunk items records the device uuid for each stripes

Device extent items record better back refs to the chunk tree

Block groups record better back refs to the chunk tree

The chunk tree format has also changed.  The objectid of BTRFS_CHUNK_ITEM_KEY
used to be the logical offset of the chunk.  Now it is a chunk tree id,
with the logical offset being stored in the offset field of the key.

This allows a single chunk tree to record multiple logical address spaces,
upping the number of bytes indexed by a chunk tree from 2^64 to
2^128.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 98d20f67cf Add a min size parameter to btrfs_alloc_extent
On huge machines, delayed allocation may try to allocate massive extents.
This change allows btrfs_alloc_extent to return something smaller than
the caller asked for, and the data allocation routines will loop over
the allocations until it fills the whole delayed alloc.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason ce9adaa5a7 Btrfs: Do metadata checksums for reads via a workqueue
Before, metadata checksumming was done by the callers of read_tree_block,
which would set EXTENT_CSUM bits in the extent tree to show that a given
range of pages was already checksummed and didn't need to be verified
again.

But, those bits could go away via try_to_releasepage, and the end
result was bogus checksum failures on pages that never left the cache.

The new code validates checksums when the page is read.  It is a little
tricky because metadata blocks can span pages and a single read may
end up going via multiple bios.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason d18a2c4475 Btrfs: Fix allocation profile init
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 611f0e00a2 Btrfs: Add support for duplicate blocks on a single spindle
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 8790d502e4 Btrfs: Add support for mirroring across drives
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 63b10fc487 Reorder the flags field in struct btrfs_header and record a flag on writeout
This allows detection of blocks that have already been written in the
running transaction so they can be recowed instead of modified again.
It is step one in trusting the transid field of the block pointers.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 0416008814 Create a btrfs backing dev info
This allows intelligent versions of unplug and congestion functions

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 593060d756 Btrfs: Implement raid0 when multiple devices are present
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 8a4b83cc8b Btrfs: Add support for device scanning and detection ioctls
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 239b14b32d Btrfs: Bring back mount -o ssd optimizations
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 0d81ba5dbe Btrfs: Move device information into the super block so it can be scanned
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason e085def2c4 Btrfs: Make the FS tree the last objectid in the tree of tree roots
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 6324fbf334 Btrfs: Dynamic chunk and block group allocation
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 0b86a832a1 Btrfs: Add support for multiple devices per filesystem
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 065631f6dc Btrfs: checksum file data at bio submission time instead of during writepage
When we checkum file data during writepage, the checksumming is done one
page at a time, making it difficult to do bulk metadata modifications
to insert checksums for large ranges of the file at once.

This patch changes btrfs to checksum on a per-bio basis instead.  The
bios are checksummed before they are handed off to the block layer, so
each bio is contiguous and only has pages from the same inode.

Checksumming on a bio basis allows us to insert and modify the file
checksum items in large groups.  It also allows the checksumming to
be done more easily by async worker threads.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
David Miller df68b8a7ad Btrfs: unaligned access fixes
Btrfs set/get macros lose type information needed to avoid
unaligned accesses on sparc64.
ere is a patch for the kernel bits which fixes most of the
unaligned accesses on sparc64.

btrfs_name_hash is modified to return the hash value instead
of getting a return location via a (potentially unaligned)
pointer.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 9069218d44 Btrfs: Fix i_blocks accounting
Now that delayed allocation accounting works, i_blocks accounting is changed
to only modify i_blocks when extents inserted or removed.

The fillattr call is changed to include the delayed allocation byte count
in the i_blocks result.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 47b0c4f8c7 Btrfs: Update magic
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 4529ba495c Btrfs: Add data block hints to SSD mode too
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 6f568d35a0 Btrfs: mount -o max_inline=size to control the maximum inline extent size
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 9c58309d6c Btrfs: Add inode item and backref in one insert, reducing cpu usage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason 85e21bac16 Btrfs: During deletes and truncate, remove many items at once from the tree
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00
Chris Mason d1310b2e0c Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.

The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller.  This allows a few performance
optimizations and is easier to use.

A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 5f56406aab Btrfs: Fix hole insertion corner cases
There were a few places that could cause duplicate extent insertion,
this adjusts the code that creates holes to avoid it.

lookup_extent_map is changed to correctly return all of the extents in a
range, even when there are none matching at the start of the range.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason e18e4809b1 Btrfs: Add mount -o ssd, which includes optimizations for seek free storage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 2da98f003f Btrfs: Run igrab on data=ordered inodes to prevent deadlocks during writeout
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason cee36a03e8 Rework btrfs_drop_inode to avoid scheduling
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 61295eb866 Btrfs: Add drop inode func to avoid data=ordered deadlock
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 69a32ac517 Btrfs: Change magic string to reflect new format
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Yan fdebe2bd70 Btrfs: Add readonly inode flag
This patch adds readonly inode flag support.  A file with this flag
can't be modified, but can be deleted.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 21ad10cf3e Btrfs: Add flush barriers on commit
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Yan b98b6767a0 Btrfs: Add inode flags support
This patch adds NODATASUM & NODATACOW inode flags support.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason e2008b6140 Btrfs: Add some simple throttling to wait for data=ordered and snapshot deletion
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason dc17ff8f11 Btrfs: Add data=ordered support
This forces file data extents down the disk along with the metadata that
references them.  The current implementation is fairly simple, and just
writes out all of the dirty pages in an inode before the commit.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason 4313b3994d Btrfs: Reduce stack usage in the resizer, fix 32 bit compiles
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 8f662a76c6 Btrfs: Add readahead to the online shrinker, and a mount -o alloc_start= for testing
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason edbd8d4efe Btrfs: Support for online FS resize (grow and shrink)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 1832a6d5ee Btrfs: Implement basic support for -ENOSPC
This is intended to prevent accidentally filling the drive.  A determined
user can still make things oops.

It includes some accounting of the current bytes under delayed allocation,
but this will change as things get optimized

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 6da6abae02 Btrfs: Back port to 2.6.18-el kernels
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason c59f8951d4 Btrfs: Add mount option to enforce a max extent size
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason be20aa9dba Btrfs: Add mount option to turn off data cow
A number of workloads do not require copy on write data or checksumming.
mount -o nodatasum to disable checksums and -o nodatacow to disable
both copy on write and checksumming.

In nodatacow mode, copy on write is still performed when a given extent
is under snapshot.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason b6cda9bcb4 Btrfs: Add mount -o nodatasum to turn of file data checksumming
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason f6dbff55d7 Btrfs: Reorder extent back refs to differentiate btree blocks from file data
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 3954401fa6 Btrfs: Add back pointers from the inode to the directory that references it
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 7bb86316c3 Btrfs: Add back pointers from extents to the btree or file referencing them
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 74493f7a59 Btrfs: Implement generation numbers in block pointers
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 87ee04eb0f Btrfs: Add simple stripe size parameter
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason 00f5c795fc btrfs_drop_extents: make sure the item is getting smaller before truncate
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Yan 324ae4df00 Btrfs: Add block group pinned accounting back
This patch adds a helper function 'update_pinned_extents' to
extent-tree.c. The usage of the helper function is similar to
'update_block_group',  the last parameter of the function indicates
pin vs unpin.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Josef Bacik 5103e947b9 xattr support for btrfs
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason e644d021e3 Fix recursive KM_USER1 usage in btrfs_realloc_node
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason f84a8b362d Btrfs: Optimize allocations as we need to mix data and metadata into one group
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason 179e29e488 Btrfs: Fix a number of inline extent problems that Yan Zheng reported.
The fixes do a number of things:

1) Most btrfs_drop_extent callers will try to leave the inline extents in
place.  It can truncate bytes off the beginning of the inline extent if
required.

2) writepage can now update the inline extent, allowing mmap writes to
go directly into the inline extent.

3) btrfs_truncate_in_transaction truncates inline extents

4) extent_map.c fixed to not merge inline extent mappings and hole
mappings together

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason f578d4bd7e Btrfs: Optimize csum insertion to create larger items when possible
This reduces the number of calls to btrfs_extend_item and greatly lowers
the cpu usage while writing large files.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason 6d7231f7d3 Btrfs: Fix typo: owner is a 64 bit field
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason a6b6e75e09 Btrfs: Defrag only leaves, and only when the parent node has a single objectid
This allows us to defrag huge directories, but skip the expensive defrag
case in more common usage, where it does not help as much.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason 19c00ddcc3 Btrfs: Add back metadata checksumming
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason 0f82731fc5 Breakout BTRFS_SETGET_FUNCS into a separate C file, the inlines were too big.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason 810191ff30 Btrfs: extent_map optimizations to cut down on CPU usage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason 3326d1b07c Btrfs: Allow tails larger than one page
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason 14048ed0c4 Btrfs: Cache extent buffer mappings
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason db94535db7 Btrfs: Allow tree blocks larger than the page size
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason 1a5bc167f6 Btrfs: Change the remaining radix trees used by extent-tree.c to extent_map trees
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00