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Struct bio has a reference count that controls when it can be freed.
Most uses cases is allocating the bio, which then returns with a
single reference to it, doing IO, and then dropping that single
reference. We can remove this atomic_dec_and_test() in the completion
path, if nobody else is holding a reference to the bio.
If someone does call bio_get() on the bio, then we flag the bio as
now having valid count and that we must properly honor the reference
count when it's being put.
Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"A few more btrfs fixes.
These range from corners Filipe found in the new free space cache
writeback to a grab bag of fixes from the list"
* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: btrfs_release_extent_buffer_page didn't free pages of dummy extent
Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.
btrfs: unlock i_mutex after attempting to delete subvolume during send
btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache
btrfs: fix race on ENOMEM in alloc_extent_buffer
btrfs: handle ENOMEM in btrfs_alloc_tree_block
Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
Btrfs: don't check for delalloc_bytes in cache_save_setup
Btrfs: fix deadlock when starting writeback of bg caches
Btrfs: fix race between start dirty bg cache writeout and bg deletion
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btrfs_release_extent_buffer_page() can't handle dummy extent that
allocated by btrfs_clone_extent_buffer() properly. That is because
reference count of pages that allocated by btrfs_clone_extent_buffer()
was 2, 1 by alloc_page(), and another by attach_extent_buffer_page().
Running following command repeatly can check this memory leak problem
btrfs inspect-internal inode-resolve 256 /mnt/btrfs
Signed-off-by: Chien-Kuan Yeh <ckya@synology.com>
Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Filipe hit two problems in my block group cache patches. We finalized
the fixes last week and ran through more tests"
* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: prevent list corruption during free space cache processing
Btrfs: fix inode cache writeout
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
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We need to fill inode when we found a node for it in delayed_nodes_tree.
But we did not fill the ->last_trans currently, it will cause the test
of xfstest/generic/311 fail. Scenario of the 311 is shown as below:
Problem:
(1). test_fd = open(fname, O_RDWR|O_DIRECT)
(2). pwrite(test_fd, buf, 4096, 0)
(3). close(test_fd)
(4). drop_all_caches() <-------- "echo 3 > /proc/sys/vm/drop_caches"
(5). test_fd = open(fname, O_RDWR|O_DIRECT)
(6). fsync(test_fd);
<-------- we did not get the correct log entry for the file
Reason:
When we re-open this file in (5), we would find a node
in delayed_nodes_tree and fill the inode we are lookup with the
information. But the ->last_trans is not filled, then the fsync()
will check the ->last_trans and found it's 0 then say this inode
is already in our tree which is commited, not recording the extents
for it.
Fix:
This patch fill the ->last_trans properly and set the
runtime_flags if needed in this situation. Then we can get the
log entries we expected after (6) and generic/311 passed.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Whenever the check for a send in progress introduced in commit
521e0546c970 (btrfs: protect snapshots from deleting during send) is
hit, we return without unlocking inode->i_mutex. This is easy to see
with lockdep enabled:
[ +0.000059] ================================================
[ +0.000028] [ BUG: lock held when returning to user space! ]
[ +0.000029] 4.0.0-rc5-00096-g3c435c1 #93 Not tainted
[ +0.000026] ------------------------------------------------
[ +0.000029] btrfs/211 is leaving the kernel with locks still held!
[ +0.000029] 1 lock held by btrfs/211:
[ +0.000023] #0: (&type->i_mutex_dir_key){+.+.+.}, at: [<ffffffff8135b8df>] btrfs_ioctl_snap_destroy+0x2df/0x7a0
Make sure we unlock it in the error path.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
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If io_ctl_prepare_pages fails, the pages in io_ctl.pages are not valid.
When we try to access them later, things will blow up in various ways.
Also fix the comment about the return value, which is an errno on error,
not -1, and update the cases where it was not.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Consider the following interleaving of overlapping calls to
alloc_extent_buffer:
Call 1:
- Successfully allocates a few pages with find_or_create_page
- find_or_create_page fails, goto free_eb
- Unlocks the allocated pages
Call 2:
- Calls find_or_create_page and gets a page in call 1's extent_buffer
- Finds that the page is already associated with an extent_buffer
- Grabs a reference to the half-written extent_buffer and calls
mark_extent_buffer_accessed on it
mark_extent_buffer_accessed will then try to call mark_page_accessed on
a null page and panic.
The fix is to decrement the reference count on the half-written
extent_buffer before unlocking the pages so call 2 won't use it. We
should also set exists = NULL in the case that we don't use exists to
avoid accidentally returning a freed extent_buffer in an error case.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
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This is one of the first places to give out when memory is tight. Handle
it properly rather than with a BUG_ON.
Also fix the comment about the return value, which is an ERR_PTR, not
NULL, on error.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
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If device tree has hole, find_free_dev_extent() cannot find available
address properly.
The problem can be reproduce by following script.
mntpath=/btrfs
loopdev=/dev/loop0
filepath=/home/forrest/image
umount $mntpath
losetup -d $loopdev
truncate --size 100g $filepath
losetup $loopdev $filepath
mkfs.btrfs -f $loopdev
mount $loopdev $mntpath
# make device tree with one big hole
for i in `seq 1 1 100`; do
fallocate -l 1g $mntpath/$i
done
sync
for i in `seq 1 1 95`; do
rm $mntpath/$i
done
sync
# wait cleaner thread remove unused block group
sleep 300
fallocate -l 1g $mntpath/aaa
# failed to allocate new chunk
fallocate -l 1g $mntpath/bbb
Above script will make device tree with one big hole, and can only allocate
just one chunk in a transaction, so failed to allocate new chunk for $mntpath/bbb
item 8 key (1 DEV_EXTENT 2185232384) itemoff 15859 itemsize 48
dev extent chunk_tree 3
chunk objectid 256 chunk offset 106292051968 length 1073741824
item 9 key (1 DEV_EXTENT 104190705664) itemoff 15811 itemsize 48
dev extent chunk_tree 3
chunk objectid 256 chunk offset 103108575232 length 1073741824
Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Now that we're doing free space cache writeback outside the critical
section in the commit, there is a bigger window for delalloc_bytes to
be added after a cache has been written. find_free_extent may do this
without putting the block group back into the dirty list, and also
without a transaction running.
Checking for delalloc_bytes in cache_save_setup means we might leave the
cache marked as written without invalidating it. Consistency checks
during mount will toss the cache, but it's better to get rid of the
check in cache_save_setup and let it get invalidated by the checks
already done during cache write out.
Signed-off-by: Chris Mason <clm@fb.com>
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While starting the writes of the dirty block group caches, if we don't
find a block group item in the extent tree we were leaving without
releasing our path, running delayed references and then looping again to
process any new dirty block groups. However this second iteration of the
loop could cause a deadlock because it tries to lock some other extent
tree node/leaf which another task already locked and it's blocked because
it's waiting for a lock on some node/leaf that is in our path that was not
released before.
We could also deadlock when running the delayed references - as we could
end up trying to lock the same nodes/leafs that we have in our local path
(with a different lock type).
Got into such case when running xfstests:
[20892.242791] ------------[ cut here ]------------
[20892.243776] WARNING: CPU: 0 PID: 13299 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[20892.245874] BTRFS: Transaction aborted (error -2)
(...)
[20892.269378] Call Trace:
[20892.269915] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.271097] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.272173] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.273386] [<ffffffffa0509a6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.274857] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[20892.275851] [<ffffffffa0509a6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.277341] [<ffffffffa0515e10>] write_one_cache_group+0x68/0xaf [btrfs]
[20892.278628] [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.280191] [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
(...)
[20892.291316] ---[ end trace 597f77e664245373 ]---
[20892.293955] BTRFS: error (device sdg) in write_one_cache_group:3184: errno=-2 No such entry
[20892.297390] BTRFS info (device sdg): forced readonly
[20892.298222] ------------[ cut here ]------------
[20892.299190] WARNING: CPU: 0 PID: 13299 at fs/btrfs/ctree.c:2683 btrfs_search_slot+0x7e/0x7d2 [btrfs]()
(...)
[20892.326253] Call Trace:
[20892.326904] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.329503] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.330815] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.332556] [<ffffffffa0510b73>] ? btrfs_search_slot+0x7e/0x7d2 [btrfs]
[20892.333955] [<ffffffff81045f62>] warn_slowpath_null+0x1a/0x1c
[20892.335562] [<ffffffffa0510b73>] btrfs_search_slot+0x7e/0x7d2 [btrfs]
[20892.336849] [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc
[20892.338222] [<ffffffffa051ad52>] ? cache_save_setup+0x43/0x2a5 [btrfs]
[20892.339823] [<ffffffffa051ad66>] ? cache_save_setup+0x57/0x2a5 [btrfs]
[20892.341275] [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46
[20892.342810] [<ffffffffa0515de7>] write_one_cache_group+0x3f/0xaf [btrfs]
[20892.344184] [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.347162] [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
(...)
[20892.361015] ---[ end trace 597f77e664245374 ]---
[21120.688097] INFO: task kworker/u8:17:29854 blocked for more than 120 seconds.
[21120.689881] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2
[21120.691384] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.703696] Call Trace:
[21120.704310] [<ffffffff8143107e>] schedule+0x74/0x83
[21120.705490] [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs]
[21120.706757] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.708156] [<ffffffffa054ac1e>] lock_extent_buffer_for_io+0x3e/0x194 [btrfs]
[21120.709892] [<ffffffffa054bb86>] ? btree_write_cache_pages+0x273/0x385 [btrfs]
[21120.711605] [<ffffffffa054bc42>] btree_write_cache_pages+0x32f/0x385 [btrfs]
[21120.723440] [<ffffffffa0527552>] btree_writepages+0x23/0x5c [btrfs]
[21120.724943] [<ffffffff8110c4c8>] do_writepages+0x23/0x2c
[21120.726008] [<ffffffff81176dde>] __writeback_single_inode+0x73/0x2fa
[21120.727230] [<ffffffff8117714a>] ? writeback_sb_inodes+0xe5/0x38b
[21120.728526] [<ffffffff811771fb>] ? writeback_sb_inodes+0x196/0x38b
[21120.729701] [<ffffffff8117726a>] writeback_sb_inodes+0x205/0x38b
(...)
[21120.747853] INFO: task btrfs:13282 blocked for more than 120 seconds.
[21120.749459] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2
[21120.751137] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.768457] Call Trace:
[21120.769039] [<ffffffff8143107e>] schedule+0x74/0x83
[21120.770107] [<ffffffffa052f25c>] btrfs_commit_transaction+0x315/0x9c9 [btrfs]
[21120.771558] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.773659] [<ffffffffa056fd8c>] prepare_to_relocate+0xcb/0xd2 [btrfs]
[21120.776257] [<ffffffffa05741da>] relocate_block_group+0x44/0x4a9 [btrfs]
[21120.777755] [<ffffffffa05747a0>] ? btrfs_relocate_block_group+0x161/0x288 [btrfs]
[21120.779459] [<ffffffffa05747a8>] btrfs_relocate_block_group+0x169/0x288 [btrfs]
[21120.781153] [<ffffffffa0550403>] btrfs_relocate_chunk.isra.29+0x3e/0xa7 [btrfs]
[21120.783918] [<ffffffffa05518fd>] btrfs_balance+0xaa4/0xc52 [btrfs]
[21120.785436] [<ffffffff8114306e>] ? cpu_cache_get.isra.39+0xe/0x1f
[21120.786434] [<ffffffffa0559252>] btrfs_ioctl_balance+0x23f/0x2b0 [btrfs]
(...)
[21120.889251] INFO: task fsstress:13288 blocked for more than 120 seconds.
[21120.890526] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2
[21120.891773] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.899960] Call Trace:
[21120.900743] [<ffffffff8143107e>] schedule+0x74/0x83
[21120.903004] [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs]
[21120.904383] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.905608] [<ffffffffa051125b>] btrfs_search_slot+0x766/0x7d2 [btrfs]
[21120.906812] [<ffffffff8114290e>] ? virt_to_head_page+0x9/0x2c
[21120.907874] [<ffffffff81144b7f>] ? cache_alloc_debugcheck_after.isra.42+0x16c/0x1cb
[21120.909551] [<ffffffffa05124e0>] btrfs_insert_empty_items+0x5d/0xa8 [btrfs]
[21120.910914] [<ffffffffa0512585>] btrfs_insert_item+0x5a/0xa5 [btrfs]
[21120.912181] [<ffffffffa0520271>] ? btrfs_create_pending_block_groups+0x96/0x130 [btrfs]
[21120.913784] [<ffffffffa052028a>] btrfs_create_pending_block_groups+0xaf/0x130 [btrfs]
[21120.915374] [<ffffffffa052ffc2>] __btrfs_end_transaction+0x84/0x366 [btrfs]
[21120.916735] [<ffffffffa05302b4>] btrfs_end_transaction+0x10/0x12 [btrfs]
[21120.917996] [<ffffffffa051ab26>] btrfs_check_data_free_space+0x11f/0x27c [btrfs]
[21120.919478] [<ffffffffa051ba25>] btrfs_delalloc_reserve_space+0x1e/0x51 [btrfs]
[21120.921226] [<ffffffffa05382f2>] btrfs_truncate_page+0x85/0x2c4 [btrfs]
[21120.923121] [<ffffffffa0538572>] btrfs_cont_expand+0x41/0x3ef [btrfs]
[21120.924449] [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs]
[21120.926602] [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc
[21120.927769] [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs]
[21120.929324] [<ffffffffa05410a0>] ? btrfs_file_write_iter+0x1a9/0x431 [btrfs]
[21120.930723] [<ffffffffa05410d9>] btrfs_file_write_iter+0x1e2/0x431 [btrfs]
[21120.931897] [<ffffffff81067d85>] ? get_parent_ip+0xe/0x3e
[21120.934446] [<ffffffff811534c3>] new_sync_write+0x7c/0xa0
[21120.935528] [<ffffffff81153b58>] vfs_write+0xb2/0x117
(...)
Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout
outside critical section in commit")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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While running xfstests I ran into the following:
[20892.242791] ------------[ cut here ]------------
[20892.243776] WARNING: CPU: 0 PID: 13299 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[20892.245874] BTRFS: Transaction aborted (error -2)
[20892.247329] Modules linked in: btrfs dm_snapshot dm_bufio dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse$
[20892.258488] CPU: 0 PID: 13299 Comm: fsstress Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2
[20892.262011] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[20892.264738] 0000000000000009 ffff880427f8bc18 ffffffff8142fa46 ffffffff8108b6a2
[20892.266244] ffff880427f8bc68 ffff880427f8bc58 ffffffff81045ea5 ffff880427f8bc48
[20892.267761] ffffffffa0509a6d 00000000fffffffe ffff8803545d6f40 ffffffffa05a15a0
[20892.269378] Call Trace:
[20892.269915] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.271097] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.272173] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.273386] [<ffffffffa0509a6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.274857] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[20892.275851] [<ffffffffa0509a6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.277341] [<ffffffffa0515e10>] write_one_cache_group+0x68/0xaf [btrfs]
[20892.278628] [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.280191] [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
[20892.281781] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[20892.282873] [<ffffffffa054163b>] btrfs_sync_file+0x313/0x387 [btrfs]
[20892.284111] [<ffffffff8117acad>] vfs_fsync_range+0x95/0xa4
[20892.285203] [<ffffffff810e603f>] ? time_hardirqs_on+0x15/0x28
[20892.286290] [<ffffffff8123960b>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[20892.287469] [<ffffffff8117acd8>] vfs_fsync+0x1c/0x1e
[20892.288412] [<ffffffff8117ae54>] do_fsync+0x34/0x4e
[20892.289348] [<ffffffff8117b07c>] SyS_fsync+0x10/0x14
[20892.290255] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17
[20892.291316] ---[ end trace 597f77e664245373 ]---
[20892.293955] BTRFS: error (device sdg) in write_one_cache_group:3184: errno=-2 No such entry
[20892.297390] BTRFS info (device sdg): forced readonly
This happens because in btrfs_start_dirty_block_groups() we splice the
transaction's list of dirty block groups into a local list and then we
keep extracting the first element of the list without holding the
cache_write_mutex mutex. This means that before we acquire that mutex
the first block group on the list might be removed by a conurrent task
running btrfs_remove_block_group(). So make sure we extract the first
element (and test the list emptyness) while holding that mutex.
Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout
outside critical section in commit")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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do_blockdev_direct_IO() increments and decrements the inode
->i_dio_count for each IO operation. It does this to protect against
truncate of a file. Block devices don't need this sort of protection.
For a capable multiqueue setup, this atomic int is the only shared
state between applications accessing the device for O_DIRECT, and it
presents a scaling wall for that. In my testing, as much as 30% of
system time is spent incrementing and decrementing this value. A mixed
read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with
better latencies too. Before:
clat percentiles (usec):
| 1.00th=[ 33], 5.00th=[ 34], 10.00th=[ 34], 20.00th=[ 34],
| 30.00th=[ 34], 40.00th=[ 34], 50.00th=[ 35], 60.00th=[ 35],
| 70.00th=[ 35], 80.00th=[ 35], 90.00th=[ 37], 95.00th=[ 80],
| 99.00th=[ 98], 99.50th=[ 151], 99.90th=[ 155], 99.95th=[ 155],
| 99.99th=[ 165]
After:
clat percentiles (usec):
| 1.00th=[ 95], 5.00th=[ 108], 10.00th=[ 129], 20.00th=[ 149],
| 30.00th=[ 155], 40.00th=[ 161], 50.00th=[ 167], 60.00th=[ 171],
| 70.00th=[ 177], 80.00th=[ 185], 90.00th=[ 201], 95.00th=[ 270],
| 99.00th=[ 390], 99.50th=[ 398], 99.90th=[ 418], 99.95th=[ 422],
| 99.99th=[ 438]
In other setups, Robert Elliott reported seeing good performance
improvements:
https://lkml.org/lkml/2015/4/3/557
The more applications accessing the device, the worse it gets.
Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells
do_blockdev_direct_IO() that it need not worry about incrementing
or decrementing the inode i_dio_count for this caller.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Elliott, Robert (Server Storage) <elliott@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
__btrfs_write_out_cache is holding the ctl->tree_lock while it prepares
a list of bitmaps to record in the free space cache. It was dropping
the lock while it worked on other components, which made a window for
free_bitmap() to free the bitmap struct without removing it from the
list.
This changes things to hold the lock the whole time, and also makes sure
we hold the lock during enospc cleanup.
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
"I've been running these through a longer set of load tests because my
commits change the free space cache writeout. It fixes commit stalls
on large filesystems (~20T space used and up) that we have been
triggering here. We were seeing new writers blocked for 10 seconds or
more during commits, which is far from good.
Josef and I fixed up ENOSPC aborts when deleting huge files (3T or
more), that are triggered because our metadata reservations were not
properly accounting for crcs and were not replenishing during the
truncate.
Also in this series, a number of qgroup fixes from Fujitsu and Dave
Sterba collected most of the pending cleanups from the list"
* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (93 commits)
btrfs: quota: Update quota tree after qgroup relationship change.
btrfs: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.
btrfs: qgroup: clear STATUS_FLAG_ON in disabling quota.
btrfs: Update btrfs qgroup status item when rescan is done.
btrfs: qgroup: Fix dead judgement on qgroup_rescan_leaf() return value.
btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created
btrfs: Check qgroup level in kernel qgroup assign.
btrfs: qgroup: allow to remove qgroup which has parent but no child.
btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
btrfs: qgroup: do a reservation in a higher level.
Btrfs: qgroup, Account data space in more proper timings.
Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
Btrfs: qgroup: free reserved in exceeding quota.
Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().
btrfs: qgroup: fix limit args override whole limit struct
btrfs: qgroup: update limit info in function btrfs_run_qgroups().
btrfs: qgroup: consolidate the parameter of fucntion update_qgroup_limit_item().
btrfs: qgroup: update qgroup in memory at the same time when we update it in btree.
btrfs: qgroup: inherit limit info from srcgroup in creating snapshot.
btrfs: Support busy loop of write and delete
...
|
|
The code to fix stalls during free spache cache IO wasn't using
the correct root when waiting on the IO for inode caches. This
is only a problem when the inode cache is enabled with
mount -o inode_cache
This fixes the inode cache writeout to preserve any error values and
makes sure not to override the root when inode cache writeout is done.
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Previous patch modified the in memory struct but it's not written in
quota tree until next commit.
So user will still get old data using "btrfs qgroup show" after
assign/remove.
This patch will call btrfs_run_qgroups in assign ioctl so it will be
updated to in memory quota trees and user will get up-to-date results.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
flags when assigning/deleting a qgroup relations.
Operation like qgroups assigning/deleting qgroup relations will mostly
cause qgroup data inconsistent, since it needs to do the full rescan to
determine whether shared extents are exclusive or still shared in
parent qgroups.
But there are some exceptions, like qgroup with only exclusive extents
(qgroup->excl == qgroup->rfer), in that case, we only needs to
modify all its parents' excl and rfer.
So this patch adds a quick path for such qgroup in qgroup
assign/remove routine, and if quick path failed, the qgroup status will
be marked INCONSISTENT, and return 1 to info user-land.
BTW since the quick path is much the same of qgroup_excl_accounting(),
so move the core of it to __qgroup_excl_accounting() and reuse it.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
we forgot to clear STATUS_FLAG_ON in quota_disable(), it
will cause a problem shown as below:
# mount /dev/sdc /mnt
# btrfs quota enable /mnt
# btrfs quota disable /mnt
# btrfs quota rescan /mnt
quota rescan started <--- expecting it fail here.
# echo $?
0
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Update qgroup status when rescan is done.
Before this patch, status item is not updated on rescan finish, which
causing the RESCAN and INCONSISTENT flags never cleared.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Old qgroup_rescan_leaf() comment indicates ret == 2 as complete and
cleared INCONSISTENT flag.
This is not true since it will never return 2, and inside it no codes
will clear INCONSISTENT flag.
The flag clearance is done in btrfs_qgroup_rescan_work().
This caused the bug that INCONSISTENT flag is never cleared.
So change the comment and fix the dead judgment.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Btrfs will create qgroup on subvolume creation if quota is enabled, but
qgroup uses the high bits(currently 16 bits) as level, to build the
inheritance.
However it is fully possible a subvolume can be created with a
subvolumeid larger than 1 << BTRFS_QGROUP_LEVEL_SHIFT, so it will be
considered as level 1 and can't be assigned to other qgroup in level 1.
This patch will prevent such things so qgroup inheritance will not be
screwed up.
The downside is very clear, btrfs subvolume number limit will decrease
from (u64 max - 256(fisrt free objectid) - 256(last free objectid)) to
(u48 max -256(first free objectid)).
But we still have near u48(that's 15 digits in dec), so that should not
be a huge problem.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Although we have qgroup level check in btrfs-progs, it's not enough
since other programe may still call ioctl directly not using
btrfs-progs. For example, systemd.
But it's btrfs-progs to be blame since we don't provide a
full-function(like subvolume create things) btrfs library with enough
check, and only rely on kernel ioctl.
So Add level checks in kernel too.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
When a qgroup has parents but no child, it should be removable in
Theory I think. But currently, we can not remove it when it has
either parent or child.
Example:
# btrfs quota enable /mnt
# btrfs qgroup create 1/0 /mnt
# btrfs qgroup create 2/0 /mnt
# btrfs qgroup assign 1/0 2/0 /mnt
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16384 16384 0 0 --- ---
1/0 0 0 0 0 2/0 ---
2/0 0 0 0 0 --- 1/0
At this time, there is no subvol or qgroup depending on it.
Just a qgroup 2/0 is its parent, but 2/0 can work well without
1/0. So I think 1/0 should be removalbe. But:
# btrfs qgroup destroy 1/0 /mnt
ERROR: unable to destroy quota group: Device or resource busy
This patch remove the check of qgroup->parent in removing it,
then we can remove a qgroup when it has a parent.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
When we create a subvol inheriting a qgroup, we need to check the level
of them. Otherwise, there is a chance a qgroup can inherit another qgroup
at the same level.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
There are two problems in qgroup:
a). The PAGE_CACHE is 4K, even when we are writing a data of 1K,
qgroup will reserve a 4K size. It will cause the last 3K in a qgroup
is not available to user.
b). When user is writing a inline data, qgroup will not reserve it,
it means this is a window we can exceed the limit of a qgroup.
The main idea of this patch is reserving the data size of write_bytes
rather than the reserve_bytes. It means qgroup will not care about
the data size btrfs will reserve for user, but only care about the
data size user is going to write. Then reserve it when user want to
write and release it in transaction committed.
In this way, qgroup can be released from the complex procedure in
btrfs and only do the reserve when user want to write and account
when the data is written in commit_transaction().
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Currenly, in data writing, ->reserved is accounted in
fill_delalloc(), but ->may_use is released in clear_bit_hook()
which is called by btrfs_finish_ordered_io(). That's too late,
that said, between fill_delalloc() and btrfs_finish_ordered_io(),
the data is doublely accounted by qgroup. It will cause some
unexpected -EDQUOT.
Example:
# btrfs quota enable /root/btrfs-auto-test/
# btrfs subvolume create /root/btrfs-auto-test//sub
Create subvolume '/root/btrfs-auto-test/sub'
# btrfs qgroup limit 1G /root/btrfs-auto-test//sub
dd if=/dev/zero of=/root/btrfs-auto-test//sub/file bs=1024 count=1500000
dd: error writing '/root/btrfs-auto-test//sub/file': Disk quota exceeded
681353+0 records in
681352+0 records out
697704448 bytes (698 MB) copied, 8.15563 s, 85.5 MB/s
It's (698 MB) when we got an -EDQUOT, but we limit it by 1G.
This patch move the btrfs_qgroup_reserve/free() for data from
btrfs_delalloc_reserve/release_metadata() to btrfs_check_data_free_space()
and btrfs_free_reserved_data_space(). Then the accounter in qgroup
will be updated at the same time with the accounter in space_info updated.
In this way, the unexpected -EDQUOT will be killed.
Reported-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Currently, for pre_alloc or delay_alloc, the bytes will be accounted
in space_info by the three guys.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
But on the other hand, in qgroup, there are only two counters to account the
bytes, qgroup->reserved and qgroup->excl. And qg->reserved accounts
bytes in space_info->bytes_may_use and qg->excl accounts bytes in
space_info->used. So the bytes in space_info->reserved is not accounted
in qgroup. If so, there is a window we can exceed the quota limit when
bytes is in space_info->reserved.
Example:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 20987904 20987904 0 10485760 --- ---
qg->excl is 20987904 larger than max_excl 10485760.
This patch introduce a new counter named may_use to qgroup, then
there are three counters in qgroup to account bytes in space_info
as below.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
qgroup->may_use --- qgroup->reserved --- qgroup->excl
With this patch applied:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
fallocate: /mnt/data9: fallocate failed: Disk quota exceeded
fallocate: /mnt/data10: fallocate failed: Disk quota exceeded
fallocate: /mnt/data11: fallocate failed: Disk quota exceeded
fallocate: /mnt/data12: fallocate failed: Disk quota exceeded
fallocate: /mnt/data13: fallocate failed: Disk quota exceeded
fallocate: /mnt/data14: fallocate failed: Disk quota exceeded
fallocate: /mnt/data15: fallocate failed: Disk quota exceeded
fallocate: /mnt/data16: fallocate failed: Disk quota exceeded
fallocate: /mnt/data17: fallocate failed: Disk quota exceeded
fallocate: /mnt/data18: fallocate failed: Disk quota exceeded
fallocate: /mnt/data19: fallocate failed: Disk quota exceeded
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 9453568 9453568 0 10485760 --- ---
Reported-by: Cyril SCETBON <cyril.scetbon@free.fr>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
When we exceed quota limit in writing, we will free
some reserved extent when we need to drop but not free
account in qgroup. It means, each time we exceed quota
in writing, there will be some remain space in qg->reserved
we can not use any more. If things go on like this, the
all space will be ate up.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
btrfs_limit_group use arg limit to override the old qgroup_limit of
corresponding qgroup. However, we should override part of old qgroup_limit
according to the bit which has been set in arg limit.
Signed-off-by: Fan Chengniang <fancn.fnst@cn.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
When we commit_transaction(), qgroups in btree should be updated.
But, limit info is not considered currently. It will cause a problem
when a qgroup of a snapshot inherit the limit info from srcqgroup,
then there is an inconsistency.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Cleanup: Change the parameter of update_qgroup_limit_item() to the family of
update_qgroup_xxx_item().
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
btree.
When we call btrfs_qgroup_inherit() with BTRFS_QGROUP_INHERIT_SET_LIMITS,
btrfs will update the limit info of qgroup in btree but forget to update
the qgroup in rbtree at the same time. It obviousely will cause an inconsistency.
This patch fix it by updating the rbtree at the same time.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Currently, when we snapshot a subvol, snapshot will not copy the limits
from srcqgroup.
This patch make the qgroup in snapshot inherit the limit info when create
a snapshot.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Reproduce:
while true; do
dd if=/dev/zero of=/mnt/btrfs/file count=[75% fs_size]
rm /mnt/btrfs/file
done
Then we can see above loop failed on NO_SPACE.
It it long-term problem since very beginning, because delayed-iput
after rm are not run.
We already have commit_transaction() in alloc_space code, but it is
not triggered in above case.
This patch trigger commit_transaction() to run delayed-iput and
reflash pinned-space to to make write success.
It is based on previous fix of delayed-iput in commit_transaction(),
need to be applied on top of:
btrfs: Fix NO_SPACE bug caused by delayed-iput
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Steps to reproduce:
while true; do
dd if=/dev/zero of=/btrfs_dir/file count=[fs_size * 75%]
rm /btrfs_dir/file
sync
done
And we'll see dd failed because btrfs return NO_SPACE.
Reason:
Normally, btrfs_commit_transaction() call btrfs_run_delayed_iputs()
in end to free fs space for next write, but sometimes it hadn't
done work on time, because btrfs-cleaner thread get delayed-iputs
from list before, but do iput() after next write.
This is log:
[ 2569.050776] comm=btrfs-cleaner func=btrfs_evict_inode() begin
[ 2569.084280] comm=sync func=btrfs_commit_transaction() call btrfs_run_delayed_iputs()
[ 2569.085418] comm=sync func=btrfs_commit_transaction() done btrfs_run_delayed_iputs()
[ 2569.087554] comm=sync func=btrfs_commit_transaction() end
[ 2569.191081] comm=dd begin
[ 2569.790112] comm=dd func=__btrfs_buffered_write() ret=-28
[ 2569.847479] comm=btrfs-cleaner func=add_pinned_bytes() 0 + 32677888 = 32677888
[ 2569.849530] comm=btrfs-cleaner func=add_pinned_bytes() 32677888 + 23834624 = 56512512
...
[ 2569.903893] comm=btrfs-cleaner func=add_pinned_bytes() 943976448 + 21762048 = 965738496
[ 2569.908270] comm=btrfs-cleaner func=btrfs_evict_inode() end
Fix:
Make btrfs_commit_transaction() wait current running btrfs-cleaner's
delayed-iputs() done in end.
Test:
Use script similar to above(more complex),
before patch:
7 failed in 100 * 20 loop.
after patch:
0 failed in 100 * 20 loop.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
space_info's value calculation is some complex and easy to cause
bug, add WARN_ON() to help debug.
Changelog v1->v2:
Put WARN_ON()s under the ENOSPC_DEBUG mount option.
Suggested by: David Sterba <dsterba@suse.cz>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Bug1:
space_info->bytes_readonly was set to very large(negative) value in
btrfs_remove_block_group().
Reason:
Current code set block_group_cache->pinned = 0 in btrfs_delete_unused_bgs(),
but above space was not counted to space_info->bytes_readonly.
Then in btrfs_remove_block_group():
block_group->space_info->bytes_readonly -= block_group->key.offset;
We can see following value in trace:
btrfs_remove_block_group: pid=2677 comm=btrfs-cleaner WARNING: bytes_readonly=12582912, key.offset=134217728
Bug2:
space_info->total_bytes_pinned grow to value larger than fs size.
In a 1.2G fs, we can get following trace log:
at first:
ZL_DEBUG: add_pinned_bytes: pid=2710 comm=sync change total_bytes_pinned flags=1 869793792 + 95944704 = 965738496
after some op:
ZL_DEBUG: add_pinned_bytes: pid=2770 comm=sync change total_bytes_pinned flags=1 1780178944 + 95944704 = 1876123648
after some op:
ZL_DEBUG: add_pinned_bytes: pid=3193 comm=sync change total_bytes_pinned flags=1 2924568576 + 95551488 = 3020120064
...
Reason:
Similar to bug1, we also need to adjust space_info->total_bytes_pinned
in above code block.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
If we have any chance to make a successful write, we should not give up.
This patch adjust commit-transaction condition from:
pinned >= wanted
to
left + pinned >= wanted
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
It is another reason for NO_SPACE case.
When we found enough free space in loop and saved them to
max_hole_start/size before, and tail space contains pending extent,
origional innocent max_hole_start/size are reset in retry.
As a result, find_free_dev_extent() returns less space than it can,
and cause NO_SPACE in user program.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Old code bypass commit transaction when we don't have enough
pinned space, but another case is there exist freed bgs in current
transction, it have possibility to make alloc_chunk success.
This patch modify the condition to:
if (have_free_bg || have_pinned_space) commit_transaction()
Confirmed above action by printk before and after patch.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Commit 0d97a64e0 creates a new variable but doesn't always set it up.
This puts it back to the original method (key.offset + 1) for the cases
not covered by Filipe's new logic.
Signed-off-by: Chris Mason <clm@fb.com>
|
|
If we attempt to clone a 0 length region into a file we can end up
inserting a range in the inode's extent_io tree with a start offset
that is greater then the end offset, which triggers immediately the
following warning:
[ 3914.619057] WARNING: CPU: 17 PID: 4199 at fs/btrfs/extent_io.c:435 insert_state+0x4b/0x10b [btrfs]()
[ 3914.620886] BTRFS: end < start 4095 4096
(...)
[ 3914.638093] Call Trace:
[ 3914.638636] [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[ 3914.639620] [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[ 3914.640789] [<ffffffffa03ca44f>] ? insert_state+0x4b/0x10b [btrfs]
[ 3914.642041] [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[ 3914.643236] [<ffffffffa03ca44f>] insert_state+0x4b/0x10b [btrfs]
[ 3914.644441] [<ffffffffa03ca729>] __set_extent_bit+0x107/0x3f4 [btrfs]
[ 3914.645711] [<ffffffffa03cb256>] lock_extent_bits+0x65/0x1bf [btrfs]
[ 3914.646914] [<ffffffff8142b2fb>] ? _raw_spin_unlock+0x28/0x33
[ 3914.648058] [<ffffffffa03cbac4>] ? test_range_bit+0xcc/0xde [btrfs]
[ 3914.650105] [<ffffffffa03cb3c3>] lock_extent+0x13/0x15 [btrfs]
[ 3914.651361] [<ffffffffa03db39e>] lock_extent_range+0x3d/0xcd [btrfs]
[ 3914.652761] [<ffffffffa03de1fe>] btrfs_ioctl_clone+0x278/0x388 [btrfs]
[ 3914.654128] [<ffffffff811226dd>] ? might_fault+0x58/0xb5
[ 3914.655320] [<ffffffffa03e0909>] btrfs_ioctl+0xb51/0x2195 [btrfs]
(...)
[ 3914.669271] ---[ end trace 14843d3e2e622fc1 ]---
This later makes the inode eviction handler enter an infinite loop that
keeps dumping the following warning over and over:
[ 3915.117629] WARNING: CPU: 22 PID: 4228 at fs/btrfs/extent_io.c:435 insert_state+0x4b/0x10b [btrfs]()
[ 3915.119913] BTRFS: end < start 4095 4096
(...)
[ 3915.137394] Call Trace:
[ 3915.137913] [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[ 3915.139154] [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[ 3915.140316] [<ffffffffa03ca44f>] ? insert_state+0x4b/0x10b [btrfs]
[ 3915.141505] [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[ 3915.142709] [<ffffffffa03ca44f>] insert_state+0x4b/0x10b [btrfs]
[ 3915.143849] [<ffffffffa03ca729>] __set_extent_bit+0x107/0x3f4 [btrfs]
[ 3915.145120] [<ffffffffa038c1e3>] ? btrfs_kill_super+0x17/0x23 [btrfs]
[ 3915.146352] [<ffffffff811548f6>] ? deactivate_locked_super+0x3b/0x50
[ 3915.147565] [<ffffffffa03cb256>] lock_extent_bits+0x65/0x1bf [btrfs]
[ 3915.148785] [<ffffffff8142b7e2>] ? _raw_write_unlock+0x28/0x33
[ 3915.149931] [<ffffffffa03bc325>] btrfs_evict_inode+0x196/0x482 [btrfs]
[ 3915.151154] [<ffffffff81168904>] evict+0xa0/0x148
[ 3915.152094] [<ffffffff811689e5>] dispose_list+0x39/0x43
[ 3915.153081] [<ffffffff81169564>] evict_inodes+0xdc/0xeb
[ 3915.154062] [<ffffffff81154418>] generic_shutdown_super+0x49/0xef
[ 3915.155193] [<ffffffff811546d1>] kill_anon_super+0x13/0x1e
[ 3915.156274] [<ffffffffa038c1e3>] btrfs_kill_super+0x17/0x23 [btrfs]
(...)
[ 3915.167404] ---[ end trace 14843d3e2e622fc2 ]---
So just bail out of the clone ioctl if the length of the region to clone
is zero, without locking any extent range, in order to prevent this issue
(same behaviour as a pwrite with a 0 length for example).
This is trivial to reproduce. For example, the steps for the test I just
made for fstests:
mkfs.btrfs -f SCRATCH_DEV
mount SCRATCH_DEV $SCRATCH_MNT
touch $SCRATCH_MNT/foo
touch $SCRATCH_MNT/bar
$CLONER_PROG -s 0 -d 4096 -l 0 $SCRATCH_MNT/foo $SCRATCH_MNT/bar
umount $SCRATCH_MNT
A test case for fstests follows soon.
CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
If we pass a length of 0 to the extent_same ioctl, we end up locking an
extent range with a start offset greater then its end offset (if the
destination file's offset is greater than zero). This results in a warning
from extent_io.c:insert_state through the following call chain:
btrfs_extent_same()
btrfs_double_lock()
lock_extent_range()
lock_extent(inode->io_tree, offset, offset + len - 1)
lock_extent_bits()
__set_extent_bit()
insert_state()
--> WARN_ON(end < start)
This leads to an infinite loop when evicting the inode. This is the same
problem that my previous patch titled
"Btrfs: fix inode eviction infinite loop after cloning into it" addressed
but for the extent_same ioctl instead of the clone ioctl.
CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
While searching for extents to clone we might find one where we only use
a part of it coming from its tail. If our destination inode is the same
the source inode, we end up removing the tail part of the extent item and
insert after a new one that point to the same extent with an adjusted
key file offset and data offset. After this we search for the next extent
item in the fs/subvol tree with a key that has an offset incremented by
one. But this second search leaves us at the new extent item we inserted
previously, and since that extent item has a non-zero data offset, it
it can make us call btrfs_drop_extents with an empty range (start == end)
which causes the following warning:
[23978.537119] WARNING: CPU: 6 PID: 16251 at fs/btrfs/file.c:550 btrfs_drop_extent_cache+0x43/0x385 [btrfs]()
(...)
[23978.557266] Call Trace:
[23978.557978] [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[23978.559191] [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[23978.560699] [<ffffffffa047f0ea>] ? btrfs_drop_extent_cache+0x43/0x385 [btrfs]
[23978.562389] [<ffffffff8104544d>] warn_slowpath_null+0x1a/0x1c
[23978.563613] [<ffffffffa047f0ea>] btrfs_drop_extent_cache+0x43/0x385 [btrfs]
[23978.565103] [<ffffffff810e3a18>] ? time_hardirqs_off+0x15/0x28
[23978.566294] [<ffffffff81079ff8>] ? trace_hardirqs_off+0xd/0xf
[23978.567438] [<ffffffffa047f73d>] __btrfs_drop_extents+0x6b/0x9e1 [btrfs]
[23978.568702] [<ffffffff8107c03f>] ? trace_hardirqs_on+0xd/0xf
[23978.569763] [<ffffffff811441c0>] ? ____cache_alloc+0x69/0x2eb
[23978.570817] [<ffffffff81142269>] ? virt_to_head_page+0x9/0x36
[23978.571872] [<ffffffff81143c15>] ? cache_alloc_debugcheck_after.isra.42+0x16c/0x1cb
[23978.573466] [<ffffffff811420d5>] ? kmemleak_alloc_recursive.constprop.52+0x16/0x18
[23978.574962] [<ffffffffa0480d07>] btrfs_drop_extents+0x66/0x7f [btrfs]
[23978.576179] [<ffffffffa049aa35>] btrfs_clone+0x516/0xaf5 [btrfs]
[23978.577311] [<ffffffffa04983dc>] ? lock_extent_range+0x7b/0xcd [btrfs]
[23978.578520] [<ffffffffa049b2a2>] btrfs_ioctl_clone+0x28e/0x39f [btrfs]
[23978.580282] [<ffffffffa049d9ae>] btrfs_ioctl+0xb51/0x219a [btrfs]
(...)
[23978.591887] ---[ end trace 988ec2a653d03ed3 ]---
Then we attempt to insert a new extent item with a key that already
exists, which makes btrfs_insert_empty_item return -EEXIST resulting in
abortion of the current transaction:
[23978.594355] WARNING: CPU: 6 PID: 16251 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
(...)
[23978.622589] Call Trace:
[23978.623181] [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[23978.624359] [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[23978.625573] [<ffffffffa044ab6c>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[23978.626971] [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[23978.628003] [<ffffffff8108a6c8>] ? vprintk_default+0x1d/0x1f
[23978.629138] [<ffffffffa044ab6c>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[23978.630528] [<ffffffffa049ad1b>] btrfs_clone+0x7fc/0xaf5 [btrfs]
[23978.631635] [<ffffffffa04983dc>] ? lock_extent_range+0x7b/0xcd [btrfs]
[23978.632886] [<ffffffffa049b2a2>] btrfs_ioctl_clone+0x28e/0x39f [btrfs]
[23978.634119] [<ffffffffa049d9ae>] btrfs_ioctl+0xb51/0x219a [btrfs]
(...)
[23978.647714] ---[ end trace 988ec2a653d03ed4 ]---
This is wrong because we should not process the extent item that we just
inserted previously, and instead process the extent item that follows it
in the tree
For example for the test case I wrote for fstests:
bs=$((64 * 1024))
mkfs.btrfs -f -l $bs -O ^no-holes /dev/sdc
mount /dev/sdc /mnt
xfs_io -f -c "pwrite -S 0xaa $(($bs * 2)) $(($bs * 2))" /mnt/foo
$CLONER_PROG -s $((3 * $bs)) -d $((267 * $bs)) -l 0 /mnt/foo /mnt/foo
$CLONER_PROG -s $((217 * $bs)) -d $((95 * $bs)) -l 0 /mnt/foo /mnt/foo
The second clone call fails with -EEXIST, because when we process the
first extent item (offset 262144), we drop part of it (counting from the
end) and then insert a new extent item with a key greater then the key we
found. The next time we search the tree we search for a key with offset
262144 + 1, which leaves us at the new extent item we have just inserted
but we think it refers to an extent that we need to clone.
Fix this by ensuring the next search key uses an offset corresponding to
the offset of the key we found previously plus the data length of the
corresponding extent item. This ensures we skip new extent items that we
inserted and works for the case of implicit holes too (NO_HOLES feature).
A test case for fstests follows soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
... avoiding write_iter/fcntl races.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
