The following call trace is seen when btrfs/031 test is executed in a loop,
[ 158.661848] ------------[ cut here ]------------
[ 158.662634] WARNING: CPU: 2 PID: 890 at /home/chandan/repos/linux/fs/btrfs/ioctl.c:558 create_subvol+0x3d1/0x6ea()
[ 158.664102] BTRFS: Transaction aborted (error -2)
[ 158.664774] Modules linked in:
[ 158.665266] CPU: 2 PID: 890 Comm: btrfs Not tainted 4.4.0-rc6-g511711a #2
[ 158.666251] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 158.667392] ffffffff81c0a6b0 ffff8806c7c4f8e8 ffffffff81431fc8 ffff8806c7c4f930
[ 158.668515] ffff8806c7c4f920 ffffffff81051aa1 ffff880c85aff000 ffff8800bb44d000
[ 158.669647] ffff8808863b5c98 0000000000000000 00000000fffffffe ffff8806c7c4f980
[ 158.670769] Call Trace:
[ 158.671153] [<ffffffff81431fc8>] dump_stack+0x44/0x5c
[ 158.671884] [<ffffffff81051aa1>] warn_slowpath_common+0x81/0xc0
[ 158.672769] [<ffffffff81051b27>] warn_slowpath_fmt+0x47/0x50
[ 158.673620] [<ffffffff813bc98d>] create_subvol+0x3d1/0x6ea
[ 158.674440] [<ffffffff813777c9>] btrfs_mksubvol.isra.30+0x369/0x520
[ 158.675376] [<ffffffff8108a4aa>] ? percpu_down_read+0x1a/0x50
[ 158.676235] [<ffffffff81377a81>] btrfs_ioctl_snap_create_transid+0x101/0x180
[ 158.677268] [<ffffffff81377b52>] btrfs_ioctl_snap_create+0x52/0x70
[ 158.678183] [<ffffffff8137afb4>] btrfs_ioctl+0x474/0x2f90
[ 158.678975] [<ffffffff81144b8e>] ? vma_merge+0xee/0x300
[ 158.679751] [<ffffffff8115be31>] ? alloc_pages_vma+0x91/0x170
[ 158.680599] [<ffffffff81123f62>] ? lru_cache_add_active_or_unevictable+0x22/0x70
[ 158.681686] [<ffffffff813d99cf>] ? selinux_file_ioctl+0xff/0x1d0
[ 158.682581] [<ffffffff8117b791>] do_vfs_ioctl+0x2c1/0x490
[ 158.683399] [<ffffffff813d3cde>] ? security_file_ioctl+0x3e/0x60
[ 158.684297] [<ffffffff8117b9d4>] SyS_ioctl+0x74/0x80
[ 158.685051] [<ffffffff819b2bd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
[ 158.685958] ---[ end trace 4b63312de5a2cb76 ]---
[ 158.686647] BTRFS: error (device loop0) in create_subvol:558: errno=-2 No such entry
[ 158.709508] BTRFS info (device loop0): forced readonly
[ 158.737113] BTRFS info (device loop0): disk space caching is enabled
[ 158.738096] BTRFS error (device loop0): Remounting read-write after error is not allowed
[ 158.851303] BTRFS error (device loop0): cleaner transaction attach returned -30
This occurs because,
Mount filesystem
Create subvol with ID 257
Unmount filesystem
Mount filesystem
Delete subvol with ID 257
btrfs_drop_snapshot()
Add root corresponding to subvol 257 into
btrfs_transaction->dropped_roots list
Create new subvol (i.e. create_subvol())
257 is returned as the next free objectid
btrfs_read_fs_root_no_name()
Finds the btrfs_root instance corresponding to the old subvol with ID 257
in btrfs_fs_info->fs_roots_radix.
Returns error since btrfs_root_item->refs has the value of 0.
To fix the issue the commit initializes tree root's and subvolume root's
highest_objectid when loading the roots from disk.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Replace the integers by enums for better readability. The value 2 does
not have any meaning since a717531942
"Btrfs: do less aggressive btree readahead" (2009-01-22).
Signed-off-by: David Sterba <dsterba@suse.com>
Cleanup the old facilities which use old btrfs_qgroup_reserve() function
call, replace them with the newer version, and remove the "__" prefix in
them.
Also, make btrfs_qgroup_reserve/free() functions private, as they are
now only used inside qgroup codes.
Now, the whole btrfs qgroup is swithed to use the new reserve facilities.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Use new __btrfs_delalloc_reserve_space() and
__btrfs_delalloc_release_space() to reserve and release space for
delalloc.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
While the inode cache caching kthread is calling btrfs_unpin_free_ino(),
we could have a concurrent call to btrfs_return_ino() that adds a new
entry to the root's free space cache of pinned inodes. This concurrent
call does not acquire the fs_info->commit_root_sem before adding a new
entry if the caching state is BTRFS_CACHE_FINISHED, which is a problem
because the caching kthread calls btrfs_unpin_free_ino() after setting
the caching state to BTRFS_CACHE_FINISHED and therefore races with
the task calling btrfs_return_ino(), which is adding a new entry, while
the former (caching kthread) is navigating the cache's rbtree, removing
and freeing nodes from the cache's rbtree without acquiring the spinlock
that protects the rbtree.
This race resulted in memory corruption due to double free of struct
btrfs_free_space objects because both tasks can end up doing freeing the
same objects. Note that adding a new entry can result in merging it with
other entries in the cache, in which case those entries are freed.
This is particularly important as btrfs_free_space structures are also
used for the block group free space caches.
This memory corruption can be detected by a debugging kernel, which
reports it with the following trace:
[132408.501148] slab error in verify_redzone_free(): cache `btrfs_free_space': double free detected
[132408.505075] CPU: 15 PID: 12248 Comm: btrfs-ino-cache Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1
[132408.505075] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
[132408.505075] ffff880023e7d320 ffff880163d73cd8 ffffffff8145eec7 ffffffff81095dce
[132408.505075] ffff880009735d40 ffff880163d73ce8 ffffffff81154e1e ffff880163d73d68
[132408.505075] ffffffff81155733 ffffffffa054a95a ffff8801b6099f00 ffffffffa0505b5f
[132408.505075] Call Trace:
[132408.505075] [<ffffffff8145eec7>] dump_stack+0x4f/0x7b
[132408.505075] [<ffffffff81095dce>] ? console_unlock+0x356/0x3a2
[132408.505075] [<ffffffff81154e1e>] __slab_error.isra.28+0x25/0x36
[132408.505075] [<ffffffff81155733>] __cache_free+0xe2/0x4b6
[132408.505075] [<ffffffffa054a95a>] ? __btrfs_add_free_space+0x2f0/0x343 [btrfs]
[132408.505075] [<ffffffffa0505b5f>] ? btrfs_unpin_free_ino+0x8e/0x99 [btrfs]
[132408.505075] [<ffffffff810f3b30>] ? time_hardirqs_off+0x15/0x28
[132408.505075] [<ffffffff81084d42>] ? trace_hardirqs_off+0xd/0xf
[132408.505075] [<ffffffff811563a1>] ? kfree+0xb6/0x14e
[132408.505075] [<ffffffff811563d0>] kfree+0xe5/0x14e
[132408.505075] [<ffffffffa0505b5f>] btrfs_unpin_free_ino+0x8e/0x99 [btrfs]
[132408.505075] [<ffffffffa0505e08>] caching_kthread+0x29e/0x2d9 [btrfs]
[132408.505075] [<ffffffffa0505b6a>] ? btrfs_unpin_free_ino+0x99/0x99 [btrfs]
[132408.505075] [<ffffffff8106698f>] kthread+0xef/0xf7
[132408.505075] [<ffffffff810f3b08>] ? time_hardirqs_on+0x15/0x28
[132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad
[132408.505075] [<ffffffff814653d2>] ret_from_fork+0x42/0x70
[132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad
[132408.505075] ffff880023e7d320: redzone 1:0x9f911029d74e35b, redzone 2:0x9f911029d74e35b.
[132409.501654] slab: double free detected in cache 'btrfs_free_space', objp ffff880023e7d320
[132409.503355] ------------[ cut here ]------------
[132409.504241] kernel BUG at mm/slab.c:2571!
Therefore fix this by having btrfs_unpin_free_ino() acquire the lock
that protects the rbtree while doing the searches and removing entries.
Fixes: 1c70d8fb4d ("Btrfs: fix inode caching vs tree log")
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
The free space entries are allocated using kmem_cache_zalloc(),
through __btrfs_add_free_space(), therefore we should use
kmem_cache_free() and not kfree() to avoid any confusion and
any potential problem. Looking at the kfree() definition at
mm/slab.c it has the following comment:
/*
* (...)
*
* Don't free memory not originally allocated by kmalloc()
* or you will run into trouble.
*/
So better be safe and use kmem_cache_free().
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
We loop through all of the dirty block groups during commit and write
the free space cache. In order to make sure the cache is currect, we do
this while no other writers are allowed in the commit.
If a large number of block groups are dirty, this can introduce long
stalls during the final stages of the commit, which can block new procs
trying to change the filesystem.
This commit changes the block group cache writeout to take appropriate
locks and allow it to run earlier in the commit. We'll still have to
redo some of the block groups, but it means we can get most of the work
out of the way without blocking the entire FS.
Signed-off-by: Chris Mason <clm@fb.com>
Trimming is completely transactionless, and the way it operates consists
of hiding free space entries from a block group, perform the trim/discard
and then make the free space entries visible again.
Therefore while a free space entry is being trimmed, we can have free space
cache writing running in parallel (as part of a transaction commit) which
will miss the free space entry. This means that an unmount (or crash/reboot)
after that transaction commit and mount again before another transaction
starts/commits after the discard finishes, we will have some free space
that won't be used again unless the free space cache is rebuilt. After the
unmount, fsck (btrfsck, btrfs check) reports the issue like the following
example:
*** fsck.btrfs output ***
checking extents
checking free space cache
There is no free space entry for 521764864-521781248
There is no free space entry for 521764864-1103101952
cache appears valid but isnt 29360128
Checking filesystem on /dev/sdc
UUID: b4789e27-4774-4626-98e9-ae8dfbfb0fb5
found 1235681286 bytes used err is -22
(...)
Another issue caused by this race is a crash while writing bitmap entries
to the cache, because while the cache writeout task accesses the bitmaps,
the trim task can be concurrently modifying the bitmap or worse might
be freeing the bitmap. The later case results in the following crash:
[55650.804460] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[55650.804835] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc loop parport_pc parport i2c_piix4 psmouse evdev pcspkr microcode processor i2ccore serio_raw thermal_sys button ext4 crc16 jbd2 mbcache sg sd_mod crc_t10dif sr_mod cdrom crct10dif_generic crct10dif_common ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring virtio scsi_mod e1000 [last unloaded: btrfs]
[55650.806169] CPU: 1 PID: 31002 Comm: btrfs-transacti Tainted: G W 3.17.0-rc5-btrfs-next-1+ #1
[55650.806493] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[55650.806867] task: ffff8800b12f6410 ti: ffff880071538000 task.ti: ffff880071538000
[55650.807166] RIP: 0010:[<ffffffffa037cf45>] [<ffffffffa037cf45>] write_bitmap_entries+0x65/0xbb [btrfs]
[55650.807514] RSP: 0018:ffff88007153bc30 EFLAGS: 00010246
[55650.807687] RAX: 000000005d1ec000 RBX: ffff8800a665df08 RCX: 0000000000000400
[55650.807885] RDX: ffff88005d1ec000 RSI: 6b6b6b6b6b6b6b6b RDI: ffff88005d1ec000
[55650.808017] RBP: ffff88007153bc58 R08: 00000000ddd51536 R09: 00000000000001e0
[55650.808017] R10: 0000000000000000 R11: 0000000000000037 R12: 6b6b6b6b6b6b6b6b
[55650.808017] R13: ffff88007153bca8 R14: 6b6b6b6b6b6b6b6b R15: ffff88007153bc98
[55650.808017] FS: 0000000000000000(0000) GS:ffff88023ec80000(0000) knlGS:0000000000000000
[55650.808017] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[55650.808017] CR2: 0000000002273b88 CR3: 00000000b18f6000 CR4: 00000000000006e0
[55650.808017] Stack:
[55650.808017] ffff88020e834e00 ffff880172d68db0 0000000000000000 ffff88019257c800
[55650.808017] ffff8801d42ea720 ffff88007153bd10 ffffffffa037d2fa ffff880224e99180
[55650.808017] ffff8801469a6188 ffff880224e99140 ffff880172d68c50 00000003000000b7
[55650.808017] Call Trace:
[55650.808017] [<ffffffffa037d2fa>] __btrfs_write_out_cache+0x1ea/0x37f [btrfs]
[55650.808017] [<ffffffffa037d959>] btrfs_write_out_cache+0xa1/0xd8 [btrfs]
[55650.808017] [<ffffffffa033936b>] btrfs_write_dirty_block_groups+0x4b5/0x505 [btrfs]
[55650.808017] [<ffffffffa03aa98e>] commit_cowonly_roots+0x15e/0x1f7 [btrfs]
[55650.808017] [<ffffffff813eb9c7>] ? _raw_spin_lock+0xe/0x10
[55650.808017] [<ffffffffa0346e46>] btrfs_commit_transaction+0x411/0x882 [btrfs]
[55650.808017] [<ffffffffa03432a4>] transaction_kthread+0xf2/0x1a4 [btrfs]
[55650.808017] [<ffffffffa03431b2>] ? btrfs_cleanup_transaction+0x3d8/0x3d8 [btrfs]
[55650.808017] [<ffffffff8105966b>] kthread+0xb7/0xbf
[55650.808017] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67
[55650.808017] [<ffffffff813ebeac>] ret_from_fork+0x7c/0xb0
[55650.808017] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67
[55650.808017] Code: 4c 89 ef 8d 70 ff e8 d4 fc ff ff 41 8b 45 34 41 39 45 30 7d 5c 31 f6 4c 89 ef e8 80 f6 ff ff 49 8b 7d 00 4c 89 f6 b9 00 04 00 00 <f3> a5 4c 89 ef 41 8b 45 30 8d 70 ff e8 a3 fc ff ff 41 8b 45 34
[55650.808017] RIP [<ffffffffa037cf45>] write_bitmap_entries+0x65/0xbb [btrfs]
[55650.808017] RSP <ffff88007153bc30>
[55650.815725] ---[ end trace 1c032e96b149ff86 ]---
Fix this by serializing both tasks in such a way that cache writeout
doesn't wait for the trim/discard of free space entries to finish and
doesn't miss any free space entry.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
The pending mount option(s) now share namespace and bits with the normal
options, and the existing one for (inode_cache) is unset unconditionally
at each transaction commit.
Introduce a separate namespace for pending changes and enhance the
descriptions of the intended change to use separate bits for each
action.
Signed-off-by: David Sterba <dsterba@suse.cz>
The naming is confusing, generic yet used for a specific cache. Add a
prefix 'ino_' or rename appropriately.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Currently, with inode cache enabled, we will reuse its inode id immediately
after unlinking file, we may hit something like following:
|->iput inode
|->return inode id into inode cache
|->create dir,fsync
|->power off
An easy way to reproduce this problem is:
mkfs.btrfs -f /dev/sdb
mount /dev/sdb /mnt -o inode_cache,commit=100
dd if=/dev/zero of=/mnt/data bs=1M count=10 oflag=sync
inode_id=`ls -i /mnt/data | awk '{print $1}'`
rm -f /mnt/data
i=1
while [ 1 ]
do
mkdir /mnt/dir_$i
test1=`stat /mnt/dir_$i | grep Inode: | awk '{print $4}'`
if [ $test1 -eq $inode_id ]
then
dd if=/dev/zero of=/mnt/dir_$i/data bs=1M count=1 oflag=sync
echo b > /proc/sysrq-trigger
fi
sleep 1
i=$(($i+1))
done
mount /dev/sdb /mnt
umount /dev/sdb
btrfs check /dev/sdb
We fix this problem by adding unlinked inode's id into pinned tree,
and we can not reuse them until committing transaction.
Cc: stable@vger.kernel.org
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Lets try this again. We can deadlock the box if we send on a box and try to
write onto the same fs with the app that is trying to listen to the send pipe.
This is because the writer could get stuck waiting for a transaction commit
which is being blocked by the send. So fix this by making sure looking at the
commit roots is always going to be consistent. We do this by keeping track of
which roots need to have their commit roots swapped during commit, and then
taking the commit_root_sem and swapping them all at once. Then make sure we
take a read lock on the commit_root_sem in cases where we search the commit root
to make sure we're always looking at a consistent view of the commit roots.
Previously we had problems with this because we would swap a fs tree commit root
and then swap the extent tree commit root independently which would cause the
backref walking code to screw up sometimes. With this patch we no longer
deadlock and pass all the weird send/receive corner cases. Thanks,
Reportedy-by: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source
code that outputs a more descriptive warnings. Also fix the styling
warning of redundant braces that came up as a result of this fix.
Signed-off-by: Dulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Due to an off-by-one error, it is possible to reproduce a bug
when the inode cache is used.
The same inode number is assigned twice, the second time this
leads to an EEXIST in btrfs_insert_empty_items().
The issue can happen when a file is removed right after a subvolume
is created and then a new inode number is created before the
inodes in free_inode_pinned are processed.
unlink() calls btrfs_return_ino() which calls start_caching() in this
case which adds [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID] by
searching for the highest inode (which already cannot find the
unlinked one anymore in btrfs_find_free_objectid()). So if this
unlinked inode's number is equal to the highest_ino + 1 (or >= this value
instead of > this value which was the off-by-one error), we mustn't add
the inode number to free_ino_pinned (caching_thread() does it right).
In this case we need to try directly to add the number to the inode_cache
which will fail in this case.
When this inode number is allocated while it is still in free_ino_pinned,
it is allocated and still added to the free inode cache when the
pinned inodes are processed, thus one of the following inode number
allocations will get an inode that is already in use and fail with EEXIST
in btrfs_insert_empty_items().
One example which was created with the reproducer below:
Create a snapshot, work in the newly created snapshot for the rest.
In unlink(inode 34284) call btrfs_return_ino() which calls start_caching().
start_caching() calls add_free_space [34284, 18446744073709517077].
In btrfs_return_ino(), call start_caching pinned [34284, 1] which is wrong.
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
btrfs_unpin_free_ino calls add_free_space [34284, 1].
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
EEXIST when the new inode is inserted.
One possible reproducer is this one:
#!/bin/sh
# preparation
TEST_DEV=/dev/sdc1
TEST_MNT=/mnt
umount ${TEST_MNT} 2>/dev/null || true
mkfs.btrfs -f ${TEST_DEV}
mount ${TEST_DEV} ${TEST_MNT} -o \
rw,relatime,compress=lzo,space_cache,inode_cache
btrfs subv create ${TEST_MNT}/s1
for i in `seq 34027`; do touch ${TEST_MNT}/s1/${i}; done
btrfs subv snap ${TEST_MNT}/s1 ${TEST_MNT}/s2
FILENAME=`find ${TEST_MNT}/s1/ -inum 4085 | sed 's|^.*/\([^/]*\)$|\1|'`
rm ${TEST_MNT}/s2/$FILENAME
touch ${TEST_MNT}/s2/$FILENAME
# the following steps can be repeated to reproduce the issue again and again
[ -e ${TEST_MNT}/s3 ] && btrfs subv del ${TEST_MNT}/s3
btrfs subv snap ${TEST_MNT}/s2 ${TEST_MNT}/s3
rm ${TEST_MNT}/s3/$FILENAME
touch ${TEST_MNT}/s3/$FILENAME
ls -alFi ${TEST_MNT}/s?/$FILENAME
touch ${TEST_MNT}/s3/_1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_1
touch ${TEST_MNT}/s3/_2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_2
touch ${TEST_MNT}/s3/__1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__1
touch ${TEST_MNT}/s3/__2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__2
# if the above is not enough, add the following loop:
for i in `seq 3 9`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
#for i in `seq 3 34027`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
# one of the touch(1) calls in s3 fail due to EEXIST because the inode is
# already in use that btrfs_find_ino_for_alloc() returns.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Not used for anything, and removing it avoids caller's need to
allocate a path structure.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
We're doing a unnecessary extra lookup of the ino cache's
inode when we already have it (and holding a reference)
during the process of saving the ino cache contents to disk.
Therefore remove this extra lookup.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The fact that btrfs_root_refs() returned 0 for the tree_root caused
bugs in the past, therefore it is set to 1 with this patch and
(hopefully) all affected code is adapted to this change.
I verified this change by temporarily adding WARN_ON() checks
everywhere where btrfs_root_refs() is used, checking whether the
logic of the code is changed by btrfs_root_refs() returning 1
instead of 0 for root->root_key.objectid == BTRFS_ROOT_TREE_OBJECTID.
With these added checks, I ran the xfstests './check -g auto'.
The two roots chunk_root and log_root_tree that are only referenced
by the superblock and the log_roots below the log_root_tree still
have btrfs_root_refs() == 0, only the tree_root is changed.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
It is very likely that there are lots of subvolumes/snapshots in the filesystem,
so if we use global block reservation to do inode cache truncation, we may hog
all the free space that is reserved in global rsv. So it is better that we do
the free space reservation for inode cache truncation by ourselves.
Cc: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The filesystem with inode cache was forced to be read-only when we umounted it.
Steps to reproduce:
# mkfs.btrfs -f ${DEV}
# mount -o inode_cache ${DEV} ${MNT}
# dd if=/dev/zero of=${MNT}/file1 bs=1M count=8192
# btrfs fi syn ${MNT}
# dd if=${MNT}/file1 of=/dev/null bs=1M
# rm -f ${MNT}/file1
# btrfs fi syn ${MNT}
# umount ${MNT}
It is because there was no enough space to do inode cache truncation, and then
we aborted the current transaction.
But no space error is not a serious problem when we write out the inode cache,
and it is safe that we just skip this step if we meet this problem. So we need
not abort the current transaction.
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: Josef Bacik <jbacik@fusionio.com>
In some places(such as: evicting inode), we just can not flush the reserved
space of delalloc, flushing the delayed directory index and delayed inode
is OK, but we don't try to flush those things and just go back when there is
no enough space to be reserved. This patch fixes this problem.
We defined 3 types of the flush operations: NO_FLUSH, FLUSH_LIMIT and FLUSH_ALL.
If we can in the transaction, we should not flush anything, or the deadlock
would happen, so use NO_FLUSH. If we flushing the reserved space of delalloc
would cause deadlock, use FLUSH_LIMIT. In the other cases, FLUSH_ALL is used,
and we will flush all things.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
o For space info, the type of space info is useful for debug.
o For transaction handle, its transid is useful.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
This in addition to a script in my btrfs-tracing tree will help track down space
leaks when we're getting space left over in block groups on umount. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
I-node cache forgets to reserve the space when writing out it. And when
we do some stress test, such as synctest, it will trigger WARN_ON() in
use_block_rsv().
WARNING: at fs/btrfs/extent-tree.c:5718 btrfs_alloc_free_block+0xbf/0x281 [btrfs]()
...
Call Trace:
[<ffffffff8104df86>] warn_slowpath_common+0x80/0x98
[<ffffffff8104dfb3>] warn_slowpath_null+0x15/0x17
[<ffffffffa0369c60>] btrfs_alloc_free_block+0xbf/0x281 [btrfs]
[<ffffffff810cbcb8>] ? __set_page_dirty_nobuffers+0xfe/0x108
[<ffffffffa035c040>] __btrfs_cow_block+0x118/0x3b5 [btrfs]
[<ffffffffa035c7ba>] btrfs_cow_block+0x103/0x14e [btrfs]
[<ffffffffa035e4c4>] btrfs_search_slot+0x249/0x6a4 [btrfs]
[<ffffffffa036d086>] btrfs_lookup_inode+0x2a/0x8a [btrfs]
[<ffffffffa03788b7>] btrfs_update_inode+0xaa/0x141 [btrfs]
[<ffffffffa036d7ec>] btrfs_save_ino_cache+0xea/0x202 [btrfs]
[<ffffffffa03a761e>] ? btrfs_update_reloc_root+0x17e/0x197 [btrfs]
[<ffffffffa0373867>] commit_fs_roots+0xaa/0x158 [btrfs]
[<ffffffffa03746a6>] btrfs_commit_transaction+0x405/0x731 [btrfs]
[<ffffffff810690df>] ? wake_up_bit+0x25/0x25
[<ffffffffa039d652>] ? btrfs_log_dentry_safe+0x43/0x51 [btrfs]
[<ffffffffa0381c5f>] btrfs_sync_file+0x16a/0x198 [btrfs]
[<ffffffff81122806>] ? mntput+0x21/0x23
[<ffffffff8112d150>] vfs_fsync_range+0x18/0x21
[<ffffffff8112d170>] vfs_fsync+0x17/0x19
[<ffffffff8112d316>] do_fsync+0x29/0x3e
[<ffffffff8112d348>] sys_fsync+0xb/0xf
[<ffffffff81468352>] system_call_fastpath+0x16/0x1b
Sometimes it causes BUG_ON() in the reservation code of the delayed inode
is triggered.
So we must reserve enough space for inode cache.
Note: If we can not reserve the enough space for inode cache, we will
give up writing out it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Since free space inodes now use normal checksumming we need to make sure to
account for their metadata use. So reserve metadata space, and then if we fail
to write out the metadata we can just release it, otherwise it will be freed up
when the io completes. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
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>
With xfstest 254 I can panic the box every time with the inode number caching
stuff on. This is because we clean the inodes out when we delete the subvolume,
but then we write out the inode cache which adds an inode to the subvolume inode
tree, and then when it gets evicted again the root gets added back on the dead
roots list and is deleted again, so we have a double free. To stop this from
happening just return 0 if refs is 0 (and we're not the tree root since tree
root always has refs of 0). With this fix 254 no longer panics. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Tested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This adds extra checks to make sure the inode map we are caching really
belongs to a FS root instead of a special relocation tree. It
prevents crashes during balancing operations.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
For a filesystem that has lots of files in it, the first time we mount
it with free ino caching support, it can take quite a long time to
setup the caching before we can create new files.
Here we fill the cache with [highest_ino, BTRFS_LAST_FREE_OBJECTID]
before we start the caching thread to search through the extent tree.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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>
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>
This patch changes some BUG_ON() to the error return.
(but, most callers still use BUG_ON())
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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>
A small warning popped up on ia64 because inode-map.c was comparing a
u64 object id with the ULL FIRST_FREE_OBJECTID. My first thought was
that all the OBJECTID constants should contain the u64 cast because
btrfs code deals entirely in u64s. But then I saw how large that was,
and figured I'd just fix the max() call.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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>
* 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>
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>
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>
btrfs_find_free_objectid may return a used objectid due to arithmetic
underflow. This bug may happen when parameter 'root' is tree root, so
it may cause serious problems when creating snapshot or sub-volume.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Almost none of the files including module.h need to do so,
remove them.
Include sched.h in extent-tree.c to silence a warning about cond_resched()
being undeclared.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
