Commit Graph

1427 Commits

Author SHA1 Message Date
Chris Mason 65e5341b9a Btrfs: fix off by one while setting block groups readonly
When we read in block groups, we'll set non-redundant groups
readonly if we find a raid1, DUP or raid10 group.  But the
ro code has an off by one bug in the math around testing to
make sure out accounting doesn't go wrong.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-04 16:41:39 -05:00
Chris Mason 83a50de97f Btrfs: prevent RAID level downgrades when space is low
The extent allocator has code that allows us to fill
allocations from any available block group, even if it doesn't
match the raid level we've requested.

This was put in because adding a new drive to a filesystem
made with the default mkfs options actually upgrades the metadata from
single spindle dup to full RAID1.

But, the code also allows us to allocate from a raid0 chunk when we
really want a raid1 or raid10 chunk.  This can cause big trouble because
mkfs creates a small (4MB) raid0 chunk for data and metadata which then
goes unused for raid1/raid10 installs.

The allocator will happily wander in and allocate from that chunk when
things get tight, which is not correct.

The fix here is to make sure that we provide duplication when the
caller has asked for it.  It does all the dups to be any raid level,
which preserves the dup->raid1 upgrade abilities.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-13 20:07:01 -05:00
Chris Mason cd02dca564 Btrfs: account for missing devices in RAID allocation profiles
When we mount in RAID degraded mode without adding a new device to
replace the failed one, we can end up using the wrong RAID flags for
allocations.

This results in strange combinations of block groups (raid1 in a raid10
filesystem) and corruptions when we try to allocate blocks from single
spindle chunks on drives that are actually missing.

The first device has two small 4MB chunks in it that mkfs creates and
these are usually unused in a raid1 or raid10 setup.  But, in -o degraded,
the allocator will fall back to these because the mask of desired raid groups
isn't correct.

The fix here is to count the missing devices as we build up the list
of devices in the system.  This count is used when picking the
raid level to make sure we continue using the same levels that were
in place before we lost a drive.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-13 20:06:52 -05:00
Chris Mason 68433b73b1 Btrfs: EIO when we fail to read tree roots
If we just get a plain IO error when we read tree roots, the code
wasn't properly sending that error up the chain.  This allowed mounts to
continue when they should failed, and allowed operations
on partially setup root structs.  The end result was usually oopsen
on spinlocks that hadn't been spun up correctly.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-13 14:47:58 -05:00
Jan Beulich 3dd1462e82 Btrfs: fix compiler warnings
... regarding an unused function when !MIGRATION, and regarding a
printk() format string vs argument mismatch.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:11 -05:00
Li Zefan fdfb1e4f6c Btrfs: Make async snapshot ioctl more generic
If we had reserved some bytes in struct btrfs_ioctl_vol_args, we
wouldn't have to create a new structure for async snapshot creation.

Here we convert async snapshot ioctl to use a more generic ABI, as
we'll add more ioctls for snapshots/subvolumes in the future, readonly
snapshots for example.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:11 -05:00
Xin Zhong 914ee295af Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
This problem is found in meego testing:
http://bugs.meego.com/show_bug.cgi?id=6672
A file in btrfs is mmaped and the mmaped buffer is passed to pwrite to write to the same page
of the same file. In btrfs_file_aio_write(), the pages is locked by prepare_pages(). So when
btrfs_copy_from_user() is called, page fault happens and the same page needs to be locked again
in filemap_fault(). The fix is to move iov_iter_fault_in_readable() before prepage_pages() to make page
fault happen before pages are locked. And also disable page fault in critical region in
btrfs_copy_from_user().

Reviewed-by: Yan, Zheng<zheng.z.yan@intel.com>
Signed-off-by: Zhong, Xin <xin.zhong@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:10 -05:00
Li Zefan f106e82caa Btrfs: Fix a crash when mounting a subvolume
We should drop dentry before deactivating the superblock, otherwise
we can hit this bug:

BUG: Dentry f349a690{i=100,n=/} still in use (1) [unmount of btrfs loop1]
...

Steps to reproduce the bug:

  # mount /dev/loop1 /mnt
  # mkdir save
  # btrfs subvolume snapshot /mnt save/snap1
  # umount /mnt
  # mount -o subvol=save/snap1 /dev/loop1 /mnt
  (crash)

Reported-by: Michael Niederle <mniederle@gmx.at>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:10 -05:00
Sage Weil 75eaa0e22c Btrfs: fix sync subvol/snapshot creation
We were incorrectly taking the async path even for the sync ioctls by
passing in &transid unconditionally.

There's ample room for further cleanup here, but this keeps the fix simple.

Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:10 -05:00
Yan, Zheng 24ae63656a Btrfs: Fix page leak in compressed writeback path
"start + num_bytes >= actual_end" can happen when compressed page writeback races
with file truncation. In that case we need unlock and release pages past the end
of file.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:09 -05:00
Josef Bacik 84cd948cb1 Btrfs: do not BUG if we fail to remove the orphan item for dead snapshots
Not being able to delete an orphan item isn't a horrible thing.  The worst that
happens is the next time around we try and do the orphan cleanup and we can't
find the referenced object and just delete the item and move on.

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-12-10 16:29:04 -05:00
Josef Bacik 7e1fea731d Btrfs: fixup return code for btrfs_del_orphan_item
If the orphan item doesn't exist, we return 1, which doesn't make any sense to
the callers.  Instead return -ENOENT if we didn't find the item.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-12-09 13:57:15 -05:00
Josef Bacik b8399dee47 Btrfs: do not do fast caching if we are allocating blocks for tree_root
Since the fast caching uses normal tree locking, we can possibly deadlock if we
get to the caching via a btrfs_search_slot() on the tree_root.  So just check to
see if the root we are on is the tree root, and just don't do the fast caching.

Reported-by: Sage Weil <sage@newdream.net>
Signed-off-by: Josef Bacik <josef@redhat.com>
2010-12-09 13:57:13 -05:00
Josef Bacik 2b20982e31 Btrfs: deal with space cache errors better
Currently if the space cache inode generation number doesn't match the
generation number in the space cache header we will just fail to load the space
cache, but we won't mark the space cache as an error, so we'll keep getting that
error each time somebody tries to cache that block group until we actually clear
the thing.  Fix this by marking the space cache as having an error so we only
get the message once.  This patch also makes it so that we don't try and setup
space cache for a block group that isn't cached, since we won't be able to write
it out anyway.  None of these problems are actual problems, they are just
annoying and sub-optimal.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-12-09 13:57:12 -05:00
Josef Bacik 955256f2c3 Btrfs: fix use after free in O_DIRECT
This fixes a bug where we use dip after we have freed it.  Instead just use the
file_offset that was passed to the function.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-12-09 13:57:10 -05:00
Chris Mason 5a92bc88ce Btrfs: don't use migrate page without CONFIG_MIGRATION
Fixes compile error

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-29 09:49:11 -05:00
Chris Mason 163cf09c2a Btrfs: deal with DIO bios that span more than one ordered extent
The new DIO bio splitting code has problems when the bio
spans more than one ordered extent.  This will happen as the
generic DIO code merges our get_blocks calls together into
a bigger single bio.

This fixes things by walking forward in the ordered extent
code finding all the overlapping ordered extents and completing them
all at once.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-28 19:56:33 -05:00
Josef Bacik 450ba0ea06 Btrfs: setup blank root and fs_info for mount time
There is a problem with how we use sget, it searches through the list of supers
attached to the fs_type looking for a super with the same fs_devices as what
we're trying to mount.  This depends on sb->s_fs_info being filled, but we don't
fill that in until we get to btrfs_fill_super, so we could hit supers on the
fs_type super list that have a null s_fs_info.  In order to fix that we need to
go ahead and setup a blank root with a blank fs_info to hold fs_devices, that
way our test will work out right and then we can set s_fs_info in
btrfs_set_super, and then open_ctree will simply use our pre-allocated root and
fs_info when setting everything up.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 13:37:51 -05:00
Josef Bacik 975f84fee2 Btrfs: fix fiemap
There are two big problems currently with FIEMAP

1) We return extents for holes.  This isn't supposed to happen, we just don't
return extents for holes and then userspace interprets the lack of an extent as
a hole.

2) We sometimes don't set FIEMAP_EXTENT_LAST properly.  This is because we wait
to see a EXTENT_FLAG_VACANCY flag on the em, but this won't happen if say we ask
fiemap to map up to the last extent in a file, and there is nothing but holes up
to the i_size.  To fix this we need to lookup the last extent in this file and
save the logical offset, so if we happen to try and map that extent we can be
sure to set FIEMAP_EXTENT_LAST.

With this patch we now pass xfstest 225, which we never have before.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 13:37:50 -05:00
Ian Kent 619c8c7639 Btrfs - fix race between btrfs_get_sb() and umount
When mounting a btrfs file system btrfs_test_super() may attempt to
use sb->s_fs_info, the btrfs root, of a super block that is going away
and that has had the btrfs root set to NULL in its ->put_super(). But
if the super block is going away it cannot be an existing super block
so we can return false in this case.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 13:37:44 -05:00
Josef Bacik bc1cbf1f86 Btrfs: update inode ctime when using links
Currently we fail xfstest 236 because we're not updating the inode ctime on
link.  This is a simple fix, and makes it so we pass 236 now.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 13:00:07 -05:00
Josef Bacik 0ed42a63f3 Btrfs: make sure new inode size is ok in fallocate
We have been failing xfstest 228 forever, because we don't check to make sure
the new inode size is acceptable as far as RLIMIT is concerned.  Just check to
make sure it's ok to create a inode with this new size and error out if not.
With this patch we now pass 228.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 13:00:07 -05:00
Josef Bacik 55a61d1d06 Btrfs: fix typo in fallocate to make it honor actual size
There is a typo in __btrfs_prealloc_file_range() where we set the i_size to
actual_len/cur_offset, and then just set it to cur_offset again, and do the same
with btrfs_ordered_update_i_size().  This fixes it back to keeping i_size in a
local variable and then updating i_size properly.  Tested this with

xfs_io -F -f -c "falloc 0 1" -c "pwrite 0 1" foo

stat'ing foo gives us a size of 1 instead of 4096 like it was.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-27 12:59:16 -05:00
Chris Mason 45f49bce99 Btrfs: avoid NULL pointer deref in try_release_extent_buffer
If we fail to find a pointer in the radix tree, don't try
to deref the NULL one we do have.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:27:44 -05:00
Josef Bacik a1b075d28d Btrfs: make btrfs_add_nondir take parent inode as an argument
Everybody who calls btrfs_add_nondir just passes in the dentry of the new file
and then dereference dentry->d_parent->d_inode, but everybody who calls
btrfs_add_nondir() are already passed the parent's inode.  So instead of
dereferencing dentry->d_parent, just make btrfs_add_nondir take the dir inode as
an argument and pass that along so we don't have to worry about d_parent.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:10 -05:00
Josef Bacik 495e86779f Btrfs: hold i_mutex when calling btrfs_log_dentry_safe
Since we walk up the path logging all of the parts of the inode's path, we need
to hold i_mutex to make sure that the inode is not renamed while we're logging
everything.  btrfs_log_dentry_safe does dget_parent and all of that jazz, but we
may get unexpected results if the rename changes the inode's location while
we're higher up the path logging those dentries, so do this for safety reasons.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:09 -05:00
Josef Bacik 6a91221304 Btrfs: use dget_parent where we can UPDATED
There are lots of places where we do dentry->d_parent->d_inode without holding
the dentry->d_lock.  This could cause problems with rename.  So instead we need
to use dget_parent() and hold the reference to the parent as long as we are
going to use it's inode and then dput it at the end.

Signed-off-by: Josef Bacik <josef@redhat.com>
Cc: raven@themaw.net
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:09 -05:00
Josef Bacik 7619585390 Btrfs: fix more ESTALE problems with NFS
When creating new inodes we don't setup inode->i_generation.  So if we generate
an fh with a newly created inode we save the generation of 0, but if we flush
the inode to disk and have to read it back when getting the inode on the server
we'll have the right i_generation, so gens wont match and we get ESTALE.  This
patch properly sets inode->i_generation when we create the new inode and now I'm
no longer getting ESTALE.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:08 -05:00
Josef Bacik 2ede0daf01 Btrfs: handle NFS lookups properly
People kept reporting NFS issues, specifically getting ESTALE alot.  I figured
out how to reproduce the problem

SERVER
mkfs.btrfs /dev/sda1
mount /dev/sda1 /mnt/btrfs-test
<add /mnt/btrfs-test to /etc/exports>
btrfs subvol create /mnt/btrfs-test/foo
service nfs start

CLIENT
mount server:/mnt/btrfs /mnt/test
cd /mnt/test/foo
ls

SERVER
echo 3 > /proc/sys/vm/drop_caches

CLIENT
ls			<-- get an ESTALE here

This is because the standard way to lookup a name in nfsd is to use readdir, and
what it does is do a readdir on the parent directory looking for the inode of
the child.  So in this case the parent being / and the child being foo.  Well
subvols all have the same inode number, so doing a readdir of / looking for
inode 256 will return '.', which obviously doesn't match foo.  So instead we
need to have our own .get_name so that we can find the right name.

Our .get_name will either lookup the inode backref or the root backref,
whichever we're looking for, and return the name we find.  Running the above
reproducer with this patch results in everything acting the way its supposed to.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:08 -05:00
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
Li Zefan f209561ad8 btrfs: Show device attr correctly for symlinks
Symlinks and files of other types show different device numbers, though
they are on the same partition:

 $ touch tmp; ln -s tmp tmp2; stat tmp tmp2
   File: `tmp'
   Size: 0         	Blocks: 0          IO Block: 4096   regular empty file
 Device: 15h/21d	Inode: 984027      Links: 1
 --- snip ---
   File: `tmp2' -> `tmp'
   Size: 3         	Blocks: 0          IO Block: 4096   symbolic link
 Device: 13h/19d	Inode: 984028      Links: 1

Reported-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:07 -05:00
Li Zefan 5f3888ff6f btrfs: Set file size correctly in file clone
Set src_offset = 0, src_length = 20K, dest_offset = 20K. And the
original filesize of the dest file 'file2' is 30K:

  # ls -l /mnt/file2
  -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2

Now clone file1 to file2, the dest file should be 40K, but it
still shows 30K:

  # ls -l /mnt/file2
  -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:06 -05:00
Li Zefan 2a6b8daeda btrfs: Check if dest_offset is block-size aligned before cloning file
We've done the check for src_offset and src_length, and We should
also check dest_offset, otherwise we'll corrupt the destination
file:

  (After cloning file1 to file2 with unaligned dest_offset)
  # cat /mnt/file2
  cat: /mnt/file2: Input/output error

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:05 -05:00
Josef Bacik 0de90876c6 Btrfs: handle the space_cache option properly
When I added the clear_cache option I screwed up and took the break out of
the space_cache case statement, so whenever you mount with space_cache you also
get clear_cache, which does you no good if you say set space_cache in fstab so
it always gets set.  This patch adds the break back in properly.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:05 -05:00
Arne Jansen 6f33434850 btrfs: Fix early enospc because 'unused' calculated with wrong sign.
'unused' calculated with wrong sign in reserve_metadata_bytes().
This might have lead to unwanted over-reservations.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:04 -05:00
Miao Xie e65e153554 btrfs: fix panic caused by direct IO
btrfs paniced when we write >64KB data by direct IO at one time.

Reproduce steps:
 # mkfs.btrfs /dev/sda5 /dev/sda6
 # mount /dev/sda5 /mnt
 # dd if=/dev/zero of=/mnt/tmpfile bs=100K count=1 oflag=direct

Then btrfs paniced:
mapping failed logical 1103155200 bio len 69632 len 12288
------------[ cut here ]------------
kernel BUG at fs/btrfs/volumes.c:3010!
[SNIP]
Pid: 1992, comm: btrfs-worker-0 Not tainted 2.6.37-rc1 #1 D2399/PRIMERGY
RIP: 0010:[<ffffffffa03d1462>]  [<ffffffffa03d1462>] btrfs_map_bio+0x202/0x210 [btrfs]
[SNIP]
Call Trace:
 [<ffffffffa03ab3eb>] __btrfs_submit_bio_done+0x1b/0x20 [btrfs]
 [<ffffffffa03a35ff>] run_one_async_done+0x9f/0xb0 [btrfs]
 [<ffffffffa03d3d20>] run_ordered_completions+0x80/0xc0 [btrfs]
 [<ffffffffa03d45a4>] worker_loop+0x154/0x5f0 [btrfs]
 [<ffffffffa03d4450>] ? worker_loop+0x0/0x5f0 [btrfs]
 [<ffffffffa03d4450>] ? worker_loop+0x0/0x5f0 [btrfs]
 [<ffffffff81083216>] kthread+0x96/0xa0
 [<ffffffff8100cec4>] kernel_thread_helper+0x4/0x10
 [<ffffffff81083180>] ? kthread+0x0/0xa0
 [<ffffffff8100cec0>] ? kernel_thread_helper+0x0/0x10

We fix this problem by splitting bios when we submit bios.

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>
2010-11-21 22:26:04 -05:00
Miao Xie 88f794ede7 btrfs: cleanup duplicate bio allocating functions
extent_bio_alloc() and compressed_bio_alloc() are similar, cleanup
similar source code.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:03 -05:00
Miao Xie 0c56fa9662 btrfs: fix free dip and dip->csums twice
bio_endio() will free dip and dip->csums, so dip and dip->csums twice will
be freed twice. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:02 -05:00
Chris Mason 784b4e29a2 Btrfs: add migrate page for metadata inode
Migrate page will directly call the btrfs btree writepage function,
which isn't actually allowed.

Our writepage assumes that you have locked the extent_buffer and
flagged the block as written.  Without doing these steps, we can
corrupt metadata blocks.

A later commit will remove the btree writepage function since
it is really only safely used internally by btrfs.  We
use writepages for everything else.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21 22:26:02 -05:00
Chris Mason 6418c96107 Btrfs: deal with errors from updating the tree log
During unlink we remove any references to the inode from
the tree log.  It can return -ENOENT and other errors,
and this changes the unlink code to deal with it.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-30 07:34:24 -04:00
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 531cb13f1e Btrfs: make SNAP_DESTROY async
There is no reason to force an immediate commit when deleting a snapshot.
Users have some expectation that space from a deleted snapshot be freed
immediately, but even if we do commit the reclaim is a background process.

If users _do_ want the deletion to be durable, they can call 'sync'.

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 72fd032e94 Btrfs: add SNAP_CREATE_ASYNC ioctl
Create a snap without waiting for it to commit to disk.  The ioctl is
ordered such that subsequent operations will not be contained by the
created snapshot, and the commit is initiated, but the ioctl does not
wait for the snapshot to commit to disk.

We return the specific transid to userspace so that an application can wait
for this specific snapshot creation to commit via the WAIT_SYNC ioctl.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 21:41:57 -04:00
Sage Weil 462045928b Btrfs: add START_SYNC, WAIT_SYNC ioctls
START_SYNC will start a sync/commit, but not wait for it to
complete.  Any modification started after the ioctl returns is
guaranteed not to be included in the commit.  If a non-NULL
pointer is passed, the transaction id will be returned to
userspace.

WAIT_SYNC will wait for any in-progress commit to complete.  If a
transaction id is specified, the ioctl will block and then
return (success) when the specified transaction has committed.
If it has already committed when we call the ioctl, it returns
immediately.  If the specified transaction doesn't exist, it
returns EINVAL.

If no transaction id is specified, WAIT_SYNC will wait for the
currently committing transaction to finish it's commit to disk.
If there is no currently committing transaction, it returns
success.

These ioctls are useful for applications which want to impose an
ordering on when fs modifications reach disk, but do not want to
wait for the full (slow) commit process to do so.

Picky callers can take the transid returned by START_SYNC and
feed it to WAIT_SYNC, and be certain to wait only as long as
necessary for the transaction _they_ started to reach disk.

Sloppy callers can START_SYNC and WAIT_SYNC without a transid,
and provided they didn't wait too long between the calls, they
will get the same result.  However, if a second commit starts
before they call WAIT_SYNC, they may end up waiting longer for
it to commit as well.  Even so, a START_SYNC+WAIT_SYNC still
guarantees that any operation completed before the START_SYNC
reaches disk.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:41:32 -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
Sage Weil 99d16cbcaf Btrfs: fix deadlock in btrfs_commit_transaction
We calculate timeout (either 1 or MAX_SCHEDULE_TIMEOUT) based on whether
num_writers > 1 or should_grow at the top of the loop.  Then, much much
later, we wait for that timeout if either num_writers or should_grow is
true.  However, it's possible for a racing process (calling
btrfs_end_transaction()) to decrement num_writers such that we wait
forever instead of for 1.

Fix this by deciding how long to wait when we wait.  Include a smp_mb()
before checking if the waitqueue is active to ensure the num_writers
is visible.

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
Sage Weil fccdae435c Btrfs: fix lockdep warning on clone ioctl
I'm no lockdep expert, but this appears to make the lockdep warning go
away for the i_mutex locking in the clone ioctl.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:37:33 -04:00
Sage Weil 050006a753 Btrfs: fix clone ioctl where range is adjacent to extent
We had an edge case issue where the requested range was just
following an existing extent. Instead of skipping to the next
extent, we used the previous one which lead to having zero
sized extents.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:37:33 -04:00
Sage Weil 9a019196ec Btrfs: fix delalloc checks in clone ioctl
The lookup_first_ordered_extent() was done on the wrong inode, and the
->delalloc_bytes test was wrong, as the following
btrfs_wait_ordered_range() would only invoke a range write and wouldn't
write the entire file data range. Also, a bad parameter was passed to
btrfs_wait_ordered_range().

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:37:33 -04:00
Chris Mason d8e39c457b Btrfs: drop unused variable in block_alloc_rsv
The alloc_target variable is not really used.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:17:41 -04:00