Commit Graph

233 Commits

Author SHA1 Message Date
Linus Torvalds 6a6662ced4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (114 commits)
  Btrfs: check for a null fs root when writing to the backup root log
  Btrfs: fix race during transaction joins
  Btrfs: fix a potential btrfs_bio leak on scrub fixups
  Btrfs: rename btrfs_bio multi -> bbio for consistency
  Btrfs: stop leaking btrfs_bios on readahead
  Btrfs: stop the readahead threads on failed mount
  Btrfs: fix extent_buffer leak in the metadata IO error handling
  Btrfs: fix the new inspection ioctls for 32 bit compat
  Btrfs: fix delayed insertion reservation
  Btrfs: ClearPageError during writepage and clean_tree_block
  Btrfs: be smarter about committing the transaction in reserve_metadata_bytes
  Btrfs: make a delayed_block_rsv for the delayed item insertion
  Btrfs: add a log of past tree roots
  btrfs: separate superblock items out of fs_info
  Btrfs: use the global reserve when truncating the free space cache inode
  Btrfs: release metadata from global reserve if we have to fallback for unlink
  Btrfs: make sure to flush queued bios if write_cache_pages waits
  Btrfs: fix extent pinning bugs in the tree log
  Btrfs: make sure btrfs_remove_free_space doesn't leak EAGAIN
  Btrfs: don't wait as long for more batches during SSD log commit
  ...
2011-11-06 20:03:41 -08:00
Andi Kleen ef3d0fd27e vfs: do (nearly) lockless generic_file_llseek
The i_mutex lock use of generic _file_llseek hurts.  Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.

Under high utilization this can cause llseek to scale very poorly on larger
systems.

This patch does some rethinking of the llseek locking model:

First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.

Let's look at the different seek variants:

SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.

For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now.  The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.

=> Don't need a lock.

SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.

Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET.  On non atomic 32bit it's the same
as SEEK_SET.

=> Don't need a lock, but need to use i_size_read()

SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.

=> So still need a lock, but can use a f_lock.

This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-10-28 14:58:58 +02:00
Josef Bacik 3b16a4e3c3 Btrfs: use the inode's mapping mask for allocating pages
Johannes pointed out we were allocating only kernel pages for doing writes,
which is kind of a big deal if you are on 32bit and have more than a gig of ram.
So fix our allocations to use the mapping's gfp but still clear __GFP_FS so we
don't re-enter.  Thanks,

Reported-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:45 -04:00
Josef Bacik 1b9c332b6c Btrfs: only reserve space in fallocate if we have to do a preallocate
Lukas found a problem where if he tries to fallocate over the same region twice
and the first fallocate took up all the space we would fail with ENOSPC.  This
is because we reserve the total space we want to use for fallocate, regardless
of wether or not we will have to actually preallocate.  So instead move the
check into the loop where we actually have to do the preallocate.  Thanks,

Tested-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:36 -04:00
Linus Torvalds 7fd21be75d Merge branch 'btrfs-3.0' of git://github.com/chrismason/linux
* 'btrfs-3.0' of git://github.com/chrismason/linux:
  Btrfs: force a page fault if we have a shorty copy on a page boundary
2011-10-03 12:17:44 -07:00
Josef Bacik b6316429af Btrfs: force a page fault if we have a shorty copy on a page boundary
A user reported a problem where ceph was getting into 100% cpu usage while doing
some writing.  It turns out it's because we were doing a short write on a not
uptodate page, which means we'd fall back at one page at a time and fault the
page in.  The problem is our position is on the page boundary, so our fault in
logic wasn't actually reading the page, so we'd just spin forever or until the
page got read in by somebody else.  This will force a readpage if we end up
doing a short copy.  Alexandre could reproduce this easily with ceph and reports
it fixes his problem.  I also wrote a reproducer that no longer hangs my box
with this patch.  Thanks,

Reported-and-tested-by: Alexandre Oliva <aoliva@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-09-30 15:23:54 -04:00
Jeff Liu 48802c8ae2 BTRFS: Fix lseek return value for error
The recent reworking of btrfs' lseek lead to incorrect
values being returned.  This adds checks for seeking
beyond EOF in SEEK_HOLE and makes sure the error
values come back correct.

Andi Kleen also sent in similar patches.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-09-18 10:34:02 -04:00
Linus Torvalds 0b001b2eda Merge branch 'for-linus' of git://github.com/chrismason/linux
* 'for-linus' of git://github.com/chrismason/linux:
  Btrfs: add dummy extent if dst offset excceeds file end in
  Btrfs: calc file extent num_bytes correctly in file clone
  btrfs: xattr: fix attribute removal
  Btrfs: fix wrong nbytes information of the inode
  Btrfs: fix the file extent gap when doing direct IO
  Btrfs: fix unclosed transaction handle in btrfs_cont_expand
  Btrfs: fix misuse of trans block rsv
  Btrfs: reset to appropriate block rsv after orphan operations
  Btrfs: skip locking if searching the commit root in csum lookup
  btrfs: fix warning in iput for bad-inode
  Btrfs: fix an oops when deleting snapshots
2011-09-12 11:47:49 -07:00
Miao Xie 0c1a98c814 Btrfs: fix the file extent gap when doing direct IO
When we write some data to the place that is beyond the end of the file
in direct I/O mode, a data hole will be created. And Btrfs should insert
a file extent item that point to this hole into the fs tree. But unfortunately
Btrfs forgets doing it.

The following is a simple way to reproduce it:
 # mkfs.btrfs /dev/sdc2
 # mount /dev/sdc2 /test4
 # touch /test4/a
 # dd if=/dev/zero of=/test4/a seek=8 count=1 bs=4K oflag=direct conv=nocreat,notrunc
 # umount /test4
 # btrfsck /dev/sdc2
 root 5 inode 257 errors 100

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-09-11 10:52:24 -04:00
Chris Mason 81d86e1b70 Merge branch 'btrfs-3.0' into for-linus 2011-08-18 10:38:03 -04:00
Josef Bacik f1e490a7eb Btrfs: set i_size properly when fallocating and we already
xfstests exposed a problem with preallocate when it fallocates a range that
already has an extent.  We don't set the new i_size properly because we see that
we already have an extent.  This isn't right and we should update i_size if the
space already exists.  With this patch we now pass xfstests 075.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-18 10:36:39 -04:00
Dan Carpenter 9a4327ca1f btrfs: unlock on error in btrfs_file_llseek()
There were some unlocks on error missing in a recent patch to
btrfs_file_llseek().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-18 10:16:05 -04:00
Dan Carpenter f4ac904c41 btrfs: memory leak in btrfs_add_inode_defrag()
We don't use the defrag struct on this path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-16 21:09:15 -04:00
Linus Torvalds ed8f37370d 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: (31 commits)
  Btrfs: don't call writepages from within write_full_page
  Btrfs: Remove unused variable 'last_index' in file.c
  Btrfs: clean up for find_first_extent_bit()
  Btrfs: clean up for wait_extent_bit()
  Btrfs: clean up for insert_state()
  Btrfs: remove unused members from struct extent_state
  Btrfs: clean up code for merging extent maps
  Btrfs: clean up code for extent_map lookup
  Btrfs: clean up search_extent_mapping()
  Btrfs: remove redundant code for dir item lookup
  Btrfs: make acl functions really no-op if acl is not enabled
  Btrfs: remove remaining ref-cache code
  Btrfs: remove a BUG_ON() in btrfs_commit_transaction()
  Btrfs: use wait_event()
  Btrfs: check the nodatasum flag when writing compressed files
  Btrfs: copy string correctly in INO_LOOKUP ioctl
  Btrfs: don't print the leaf if we had an error
  btrfs: make btrfs_set_root_node void
  Btrfs: fix oops while writing data to SSD partitions
  Btrfs: Protect the readonly flag of block group
  ...

Fix up trivial conflicts (due to acl and writeback cleanups) in
 - fs/btrfs/acl.c
 - fs/btrfs/ctree.h
 - fs/btrfs/extent_io.c
2011-08-02 21:14:05 -10:00
Mitch Harder 341d14f161 Btrfs: Remove unused variable 'last_index' in file.c
The variable 'last_index' is calculated in the __btrfs_buffered_write
function and passed as a parameter to the prepare_pages function,
but is not used anywhere in the prepare_pages function.

Remove instances of 'last_index' in these functions.

Signed-off-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-01 14:32:39 -04:00
Wanlong Gao a0f98dde11 Btrfs:don't check the return value of __btrfs_add_inode_defrag
Don't need to check the return value of __btrfs_add_inode_defrag(),
since it will always return 0.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-01 14:30:41 -04:00
Chris Mason b43b31bdf2 Merge branch 'alloc_path' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/btrfs-error-handling into for-linus 2011-08-01 14:27:34 -04:00
Linus Torvalds 22712200e1 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: make sure reserve_metadata_bytes doesn't leak out strange errors
  Btrfs: use the commit_root for reading free_space_inode crcs
  Btrfs: reduce extent_state lock contention for metadata
  Btrfs: remove lockdep magic from btrfs_next_leaf
  Btrfs: make a lockdep class for each root
  Btrfs: switch the btrfs tree locks to reader/writer
  Btrfs: fix deadlock when throttling transactions
  Btrfs: stop using highmem for extent_buffers
  Btrfs: fix BUG_ON() caused by ENOSPC when relocating space
  Btrfs: tag pages for writeback in sync
  Btrfs: fix enospc problems with delalloc
  Btrfs: don't flush delalloc arbitrarily
  Btrfs: use find_or_create_page instead of grab_cache_page
  Btrfs: use a worker thread to do caching
  Btrfs: fix how we merge extent states and deal with cached states
  Btrfs: use the normal checksumming infrastructure for free space cache
  Btrfs: serialize flushers in reserve_metadata_bytes
  Btrfs: do transaction space reservation before joining the transaction
  Btrfs: try to only do one btrfs_search_slot in do_setxattr
2011-07-27 16:43:52 -07:00
Josef Bacik 9e0baf60de Btrfs: fix enospc problems with delalloc
So I had this brilliant idea to use atomic counters for outstanding and reserved
extents, but this turned out to be a bad idea.  Consider this where we have 1
outstanding extent and 1 reserved extent

Reserver				Releaser
					atomic_dec(outstanding) now 0
atomic_read(outstanding)+1 get 1
atomic_read(reserved) get 1
don't actually reserve anything because
they are the same
					atomic_cmpxchg(reserved, 1, 0)
atomic_inc(outstanding)
atomic_add(0, reserved)
					free reserved space for 1 extent

Then the reserver now has no actual space reserved for it, and when it goes to
finish the ordered IO it won't have enough space to do it's allocation and you
get those lovely warnings.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-07-27 12:46:44 -04:00
Josef Bacik a94733d0bc Btrfs: use find_or_create_page instead of grab_cache_page
grab_cache_page will use mapping_gfp_mask(), which for all inodes is set to
GFP_HIGHUSER_MOVABLE.  So instead use find_or_create_page in all cases where we
need GFP_NOFS so we don't deadlock.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-07-27 12:46:43 -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
Mark Fasheh d8926bb3ba btrfs: don't BUG_ON btrfs_alloc_path() errors
This patch fixes many callers of btrfs_alloc_path() which BUG_ON allocation
failure. All the sites that are fixed in this patch were checked by me to
be fairly trivial to fix because of at least one of two criteria:

 - Callers of the function catch errors from it already so bubbling the
   error up will be handled.
 - Callers of the function might BUG_ON any nonzero return code in which
   case there is no behavior changed (but we still got to remove a BUG_ON)

The following functions were updated:

btrfs_lookup_extent, alloc_reserved_tree_block, btrfs_remove_block_group,
btrfs_lookup_csums_range, btrfs_csum_file_blocks, btrfs_mark_extent_written,
btrfs_inode_by_name, btrfs_new_inode, btrfs_symlink,
insert_reserved_file_extent, and run_delalloc_nocow

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2011-07-14 14:14:44 -07:00
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
David Sterba a4689d2bd3 btrfs: use btrfs_ino to access inode number
commit 4cb5300bc ("Btrfs: add mount -o auto_defrag") accesses inode
number directly while it should use the helper with the new inode
number allocator.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-04 08:03:46 -04:00
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
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
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 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
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 172ddd60a6 btrfs: drop gfp parameter from alloc_extent_map
pass GFP_NOFS directly to kmem_cache_alloc

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:21 +02:00
David Sterba c704005d88 btrfs: unify checking of IS_ERR and null
use IS_ERR_OR_NULL when possible, done by this coccinelle script:

@ match @
identifier id;
@@
(
- BUG_ON(IS_ERR(id) || !id);
+ BUG_ON(IS_ERR_OR_NULL(id));
|
- IS_ERR(id) || !id
+ IS_ERR_OR_NULL(id)
|
- !id || IS_ERR(id)
+ IS_ERR_OR_NULL(id)
)

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:20 +02:00
Li Zefan 33345d0152 Btrfs: Always use 64bit inode number
There's a potential problem in 32bit system when we exhaust 32bit inode
numbers and start to allocate big inode numbers, because btrfs uses
inode->i_ino in many places.

So here we always use BTRFS_I(inode)->location.objectid, which is an
u64 variable.

There are 2 exceptions that BTRFS_I(inode)->location.objectid !=
inode->i_ino: the btree inode (0 vs 1) and empty subvol dirs (256 vs 2),
and inode->i_ino will be used in those cases.

Another reason to make this change is I'm going to use a special inode
to save free ino cache, and the inode number must be > (u64)-256.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:09 +08:00
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
Tsutomu Itoh c9149235a4 Btrfs: fix compiler warning in file.c
While compiling Btrfs, I got following messages:

  CC [M]  fs/btrfs/file.o
fs/btrfs/file.c: In function '__btrfs_buffered_write':
fs/btrfs/file.c:909: warning: 'ret' may be used uninitialized in this function
  CC [M]  fs/btrfs/tree-defrag.o

This patch fixes compiler warning.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-04-05 01:19:41 -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 41415730a1 Btrfs: check return value of btrfs_search_slot properly
Doing an audit of where we use btrfs_search_slot only showed one place where we
don't check the return value of btrfs_search_slot properly.  Just fix
mark_extent_written to see if btrfs_search_slot failed and act accordingly.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:39 -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 4a64001f00 Btrfs: fix how we deal with the pages array in the write path
Really we don't need to memset the pages array at all, since we know how many
pages we're going to use in the array and pass that around.  So don't memset,
just trust we're not idiots and we pass num_pages around properly.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:16 -04:00
Josef Bacik d0215f3e5e Btrfs: simplify our write path
Our aio_write function is huge and kind of hard to follow at times.  So this
patch fixes this by breaking out the buffered and direct write paths out into
seperate functions so it's a little clearer what's going on.  I've also fixed
some wrong typing that we had and added the ability to handle getting an error
back from btrfs_set_extent_delalloc.  Tested this with xfstests and everything
came out fine.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:15 -04:00
Josef Bacik 9f570b8d48 Btrfs: fix formatting in file.c
Sorry, but these were bugging me.  Just cleanup some of the formatting in
file.c.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:13 -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 31339acd07 Btrfs: deal with short returns from copy_from_user
When copy_from_user is only able to copy some of the bytes we requested,
we may end up creating a partially up to date page.  To avoid garbage in
the page, we need to treat a partial copy as a zero length copy.

This makes the rest of the file_write code drop the page and
retry the whole copy instead of marking the partially up to
date page as dirty.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
cc: stable@kernel.org
2011-03-07 11:10:24 -05:00
Chris Mason b1bf862e9d Btrfs: fix regressions in copy_from_user handling
Commit 914ee295af fixed deadlocks in
btrfs_file_write where we would catch page faults on pages we had
locked.

But, there were a few problems:

1) The x86-32 iov_iter_copy_from_user_atomic code always fails to copy
data when the amount to copy is more than 4K and the offset to start
copying from is not page aligned.  The result was btrfs_file_write
looping forever retrying the iov_iter_copy_from_user_atomic

We deal with this by changing btrfs_file_write to drop down to single
page copies when iov_iter_copy_from_user_atomic starts returning failure.

2) The btrfs_file_write code was leaking delalloc reservations when
iov_iter_copy_from_user_atomic returned zero.  The looping above would
result in the entire filesystem running out of delalloc reservations and
constantly trying to flush things to disk.

3) btrfs_file_write will lock down page cache pages, make sure
any writeback is finished, do the copy_from_user and then release them.
Before the loop runs we check the first and last pages in the write to
see if they are only being partially modified.  If the start or end of
the write isn't aligned, we make sure the corresponding pages are
up to date so that we don't introduce garbage into the file.

With the copy_from_user changes, we're allowing the VM to reclaim the
pages after a partial update from copy_from_user, but we're not
making sure the page cache page is up to date when we loop around to
resume the write.

We deal with this by pushing the up to date checks down into the page
prep code.  This fits better with how the rest of file_write works.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
cc: stable@kernel.org
2011-03-07 10:42:27 -05:00
Linus Torvalds 007a14af26 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: check return value of alloc_extent_map()
  Btrfs - Fix memory leak in btrfs_init_new_device()
  btrfs: prevent heap corruption in btrfs_ioctl_space_info()
  Btrfs: Fix balance panic
  Btrfs: don't release pages when we can't clear the uptodate bits
  Btrfs: fix page->private races
2011-02-15 08:00:35 -08:00
Tsutomu Itoh c26a920373 Btrfs: check return value of alloc_extent_map()
I add the check on the return value of alloc_extent_map() to several places.
In addition, alloc_extent_map() returns only the address or NULL.
Therefore, check by IS_ERR() is unnecessary. So, I remove IS_ERR() checking.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:21:37 -05:00
Linus Torvalds cb5520f02c 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: (33 commits)
  Btrfs: Fix page count calculation
  btrfs: Drop __exit attribute on btrfs_exit_compress
  btrfs: cleanup error handling in btrfs_unlink_inode()
  Btrfs: exclude super blocks when we read in block groups
  Btrfs: make sure search_bitmap finds something in remove_from_bitmap
  btrfs: fix return value check of btrfs_start_transaction()
  btrfs: checking NULL or not in some functions
  Btrfs: avoid uninit variable warnings in ordered-data.c
  Btrfs: catch errors from btrfs_sync_log
  Btrfs: make shrink_delalloc a little friendlier
  Btrfs: handle no memory properly in prepare_pages
  Btrfs: do error checking in btrfs_del_csums
  Btrfs: use the global block reserve if we cannot reserve space
  Btrfs: do not release more reserved bytes to the global_block_rsv than we need
  Btrfs: fix check_path_shared so it returns the right value
  btrfs: check return value of btrfs_start_ioctl_transaction() properly
  btrfs: fix return value check of btrfs_join_transaction()
  fs/btrfs/inode.c: Add missing IS_ERR test
  btrfs: fix missing break in switch phrase
  btrfs: fix several uncheck memory allocations
  ...
2011-02-07 14:06:18 -08:00
Yan, Zheng 3a90983dbd Btrfs: Fix page count calculation
take offset of start position into account when calculating page count.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-07 14:13:51 -05:00
Josef Bacik 7adf5dfbb3 Btrfs: handle no memory properly in prepare_pages
Instead of doing a BUG_ON(1) in prepare_pages if grab_cache_page() fails, just
loop through the pages we've already grabbed and unlock and release them, then
return -ENOMEM like we should.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-28 16:42:34 -05:00
liubo 2a29edc6b6 btrfs: fix several uncheck memory allocations
To make btrfs more stable, add several missing necessary memory allocation
checks, and when no memory, return proper errno.

We've checked that some of those -ENOMEM errors will be returned to
userspace, and some will be catched by BUG_ON() in the upper callers,
and none will be ignored silently.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-28 16:40:36 -05:00