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Filipe Manana [Tue, 18 Jan 2022 13:39:34 +0000 (13:39 +0000)]
btrfs: skip reserved bytes warning on unmount after log cleanup failure
After the recent changes made by commit
c2e39305299f01 ("btrfs: clear
extent buffer uptodate when we fail to write it") and its followup fix,
commit
651740a5024117 ("btrfs: check WRITE_ERR when trying to read an
extent buffer"), we can now end up not cleaning up space reservations of
log tree extent buffers after a transaction abort happens, as well as not
cleaning up still dirty extent buffers.
This happens because if writeback for a log tree extent buffer failed,
then we have cleared the bit EXTENT_BUFFER_UPTODATE from the extent buffer
and we have also set the bit EXTENT_BUFFER_WRITE_ERR on it. Later on,
when trying to free the log tree with free_log_tree(), which iterates
over the tree, we can end up getting an -EIO error when trying to read
a node or a leaf, since read_extent_buffer_pages() returns -EIO if an
extent buffer does not have EXTENT_BUFFER_UPTODATE set and has the
EXTENT_BUFFER_WRITE_ERR bit set. Getting that -EIO means that we return
immediately as we can not iterate over the entire tree.
In that case we never update the reserved space for an extent buffer in
the respective block group and space_info object.
When this happens we get the following traces when unmounting the fs:
[174957.284509] BTRFS: error (device dm-0) in cleanup_transaction:1913: errno=-5 IO failure
[174957.286497] BTRFS: error (device dm-0) in free_log_tree:3420: errno=-5 IO failure
[174957.399379] ------------[ cut here ]------------
[174957.402497] WARNING: CPU: 2 PID:
3206883 at fs/btrfs/block-group.c:127 btrfs_put_block_group+0x77/0xb0 [btrfs]
[174957.407523] Modules linked in: btrfs overlay dm_zero (...)
[174957.424917] CPU: 2 PID:
3206883 Comm: umount Tainted: G W 5.16.0-rc5-btrfs-next-109 #1
[174957.426689] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[174957.428716] RIP: 0010:btrfs_put_block_group+0x77/0xb0 [btrfs]
[174957.429717] Code: 21 48 8b bd (...)
[174957.432867] RSP: 0018:
ffffb70d41cffdd0 EFLAGS:
00010206
[174957.433632] RAX:
0000000000000001 RBX:
ffff8b09c3848000 RCX:
ffff8b0758edd1c8
[174957.434689] RDX:
0000000000000001 RSI:
ffffffffc0b467e7 RDI:
ffff8b0758edd000
[174957.436068] RBP:
ffff8b0758edd000 R08:
0000000000000000 R09:
0000000000000000
[174957.437114] R10:
0000000000000246 R11:
0000000000000000 R12:
ffff8b09c3848148
[174957.438140] R13:
ffff8b09c3848198 R14:
ffff8b0758edd188 R15:
dead000000000100
[174957.439317] FS:
00007f328fb82800(0000) GS:
ffff8b0a2d200000(0000) knlGS:
0000000000000000
[174957.440402] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[174957.441164] CR2:
00007fff13563e98 CR3:
0000000404f4e005 CR4:
0000000000370ee0
[174957.442117] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[174957.443076] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[174957.443948] Call Trace:
[174957.444264] <TASK>
[174957.444538] btrfs_free_block_groups+0x255/0x3c0 [btrfs]
[174957.445238] close_ctree+0x301/0x357 [btrfs]
[174957.445803] ? call_rcu+0x16c/0x290
[174957.446250] generic_shutdown_super+0x74/0x120
[174957.446832] kill_anon_super+0x14/0x30
[174957.447305] btrfs_kill_super+0x12/0x20 [btrfs]
[174957.447890] deactivate_locked_super+0x31/0xa0
[174957.448440] cleanup_mnt+0x147/0x1c0
[174957.448888] task_work_run+0x5c/0xa0
[174957.449336] exit_to_user_mode_prepare+0x1e5/0x1f0
[174957.449934] syscall_exit_to_user_mode+0x16/0x40
[174957.450512] do_syscall_64+0x48/0xc0
[174957.450980] entry_SYSCALL_64_after_hwframe+0x44/0xae
[174957.451605] RIP: 0033:0x7f328fdc4a97
[174957.452059] Code: 03 0c 00 f7 (...)
[174957.454320] RSP: 002b:
00007fff13564ec8 EFLAGS:
00000246 ORIG_RAX:
00000000000000a6
[174957.455262] RAX:
0000000000000000 RBX:
00007f328feea264 RCX:
00007f328fdc4a97
[174957.456131] RDX:
0000000000000000 RSI:
0000000000000000 RDI:
0000560b8ae51dd0
[174957.457118] RBP:
0000560b8ae51ba0 R08:
0000000000000000 R09:
00007fff13563c40
[174957.458005] R10:
00007f328fe49fc0 R11:
0000000000000246 R12:
0000000000000000
[174957.459113] R13:
0000560b8ae51dd0 R14:
0000560b8ae51cb0 R15:
0000000000000000
[174957.460193] </TASK>
[174957.460534] irq event stamp: 0
[174957.461003] hardirqs last enabled at (0): [<
0000000000000000>] 0x0
[174957.461947] hardirqs last disabled at (0): [<
ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.463147] softirqs last enabled at (0): [<
ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.465116] softirqs last disabled at (0): [<
0000000000000000>] 0x0
[174957.466323] ---[ end trace
bc7ee0c490bce3af ]---
[174957.467282] ------------[ cut here ]------------
[174957.468184] WARNING: CPU: 2 PID:
3206883 at fs/btrfs/block-group.c:3976 btrfs_free_block_groups+0x330/0x3c0 [btrfs]
[174957.470066] Modules linked in: btrfs overlay dm_zero (...)
[174957.483137] CPU: 2 PID:
3206883 Comm: umount Tainted: G W 5.16.0-rc5-btrfs-next-109 #1
[174957.484691] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[174957.486853] RIP: 0010:btrfs_free_block_groups+0x330/0x3c0 [btrfs]
[174957.488050] Code: 00 00 00 ad de (...)
[174957.491479] RSP: 0018:
ffffb70d41cffde0 EFLAGS:
00010206
[174957.492520] RAX:
ffff8b08d79310b0 RBX:
ffff8b09c3848000 RCX:
0000000000000000
[174957.493868] RDX:
0000000000000001 RSI:
fffff443055ee600 RDI:
ffffffffb1131846
[174957.495183] RBP:
ffff8b08d79310b0 R08:
0000000000000000 R09:
0000000000000000
[174957.496580] R10:
0000000000000001 R11:
0000000000000000 R12:
ffff8b08d7931000
[174957.498027] R13:
ffff8b09c38492b0 R14:
dead000000000122 R15:
dead000000000100
[174957.499438] FS:
00007f328fb82800(0000) GS:
ffff8b0a2d200000(0000) knlGS:
0000000000000000
[174957.500990] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[174957.502117] CR2:
00007fff13563e98 CR3:
0000000404f4e005 CR4:
0000000000370ee0
[174957.503513] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[174957.504864] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[174957.506167] Call Trace:
[174957.506654] <TASK>
[174957.507047] close_ctree+0x301/0x357 [btrfs]
[174957.507867] ? call_rcu+0x16c/0x290
[174957.508567] generic_shutdown_super+0x74/0x120
[174957.509447] kill_anon_super+0x14/0x30
[174957.510194] btrfs_kill_super+0x12/0x20 [btrfs]
[174957.511123] deactivate_locked_super+0x31/0xa0
[174957.511976] cleanup_mnt+0x147/0x1c0
[174957.512610] task_work_run+0x5c/0xa0
[174957.513309] exit_to_user_mode_prepare+0x1e5/0x1f0
[174957.514231] syscall_exit_to_user_mode+0x16/0x40
[174957.515069] do_syscall_64+0x48/0xc0
[174957.515718] entry_SYSCALL_64_after_hwframe+0x44/0xae
[174957.516688] RIP: 0033:0x7f328fdc4a97
[174957.517413] Code: 03 0c 00 f7 d8 (...)
[174957.521052] RSP: 002b:
00007fff13564ec8 EFLAGS:
00000246 ORIG_RAX:
00000000000000a6
[174957.522514] RAX:
0000000000000000 RBX:
00007f328feea264 RCX:
00007f328fdc4a97
[174957.523950] RDX:
0000000000000000 RSI:
0000000000000000 RDI:
0000560b8ae51dd0
[174957.525375] RBP:
0000560b8ae51ba0 R08:
0000000000000000 R09:
00007fff13563c40
[174957.526763] R10:
00007f328fe49fc0 R11:
0000000000000246 R12:
0000000000000000
[174957.528058] R13:
0000560b8ae51dd0 R14:
0000560b8ae51cb0 R15:
0000000000000000
[174957.529404] </TASK>
[174957.529843] irq event stamp: 0
[174957.530256] hardirqs last enabled at (0): [<
0000000000000000>] 0x0
[174957.531061] hardirqs last disabled at (0): [<
ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.532075] softirqs last enabled at (0): [<
ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.533083] softirqs last disabled at (0): [<
0000000000000000>] 0x0
[174957.533865] ---[ end trace
bc7ee0c490bce3b0 ]---
[174957.534452] BTRFS info (device dm-0): space_info 4 has
1070841856 free, is not full
[174957.535404] BTRFS info (device dm-0): space_info total=
1073741824, used=
2785280, pinned=0, reserved=49152, may_use=0, readonly=65536 zone_unusable=0
[174957.537029] BTRFS info (device dm-0): global_block_rsv: size 0 reserved 0
[174957.537859] BTRFS info (device dm-0): trans_block_rsv: size 0 reserved 0
[174957.538697] BTRFS info (device dm-0): chunk_block_rsv: size 0 reserved 0
[174957.539552] BTRFS info (device dm-0): delayed_block_rsv: size 0 reserved 0
[174957.540403] BTRFS info (device dm-0): delayed_refs_rsv: size 0 reserved 0
This also means that in case we have log tree extent buffers that are
still dirty, we can end up not cleaning them up in case we find an
extent buffer with EXTENT_BUFFER_WRITE_ERR set on it, as in that case
we have no way for iterating over the rest of the tree.
This issue is very often triggered with test cases generic/475 and
generic/648 from fstests.
The issue could almost be fixed by iterating over the io tree attached to
each log root which keeps tracks of the range of allocated extent buffers,
log_root->dirty_log_pages, however that does not work and has some
inconveniences:
1) After we sync the log, we clear the range of the extent buffers from
the io tree, so we can't find them after writeback. We could keep the
ranges in the io tree, with a separate bit to signal they represent
extent buffers already written, but that means we need to hold into
more memory until the transaction commits.
How much more memory is used depends a lot on whether we are able to
allocate contiguous extent buffers on disk (and how often) for a log
tree - if we are able to, then a single extent state record can
represent multiple extent buffers, otherwise we need multiple extent
state record structures to track each extent buffer.
In fact, my earlier approach did that:
https://lore.kernel.org/linux-btrfs/
3aae7c6728257c7ce2279d6660ee2797e5e34bbd.
1641300250.git.fdmanana@suse.com/
However that can cause a very significant negative impact on
performance, not only due to the extra memory usage but also because
we get a larger and deeper dirty_log_pages io tree.
We got a report that, on beefy machines at least, we can get such
performance drop with fsmark for example:
https://lore.kernel.org/linux-btrfs/
20220117082426.GE32491@xsang-OptiPlex-9020/
2) We would be doing it only to deal with an unexpected and exceptional
case, which is basically failure to read an extent buffer from disk
due to IO failures. On a healthy system we don't expect transaction
aborts to happen after all;
3) Instead of relying on iterating the log tree or tracking the ranges
of extent buffers in the dirty_log_pages io tree, using the radix
tree that tracks extent buffers (fs_info->buffer_radix) to find all
log tree extent buffers is not reliable either, because after writeback
of an extent buffer it can be evicted from memory by the release page
callback of the btree inode (btree_releasepage()).
Since there's no way to be able to properly cleanup a log tree without
being able to read its extent buffers from disk and without using more
memory to track the logical ranges of the allocated extent buffers do
the following:
1) When we fail to cleanup a log tree, setup a flag that indicates that
failure;
2) Trigger writeback of all log tree extent buffers that are still dirty,
and wait for the writeback to complete. This is just to cleanup their
state, page states, page leaks, etc;
3) When unmounting the fs, ignore if the number of bytes reserved in a
block group and in a space_info is not 0 if, and only if, we failed to
cleanup a log tree. Also ignore only for metadata block groups and the
metadata space_info object.
This is far from a perfect solution, but it serves to silence test
failures such as those from generic/475 and generic/648. However having
a non-zero value for the reserved bytes counters on unmount after a
transaction abort, is not such a terrible thing and it's completely
harmless, it does not affect the filesystem integrity in any way.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Tom Rix [Fri, 21 Jan 2022 13:45:22 +0000 (05:45 -0800)]
btrfs: fix use of uninitialized variable at rm device ioctl
Clang static analysis reports this problem
ioctl.c:3333:8: warning: 3rd function call argument is an
uninitialized value
ret = exclop_start_or_cancel_reloc(fs_info,
cancel is only set in one branch of an if-check and is always used. So
initialize to false.
Fixes:
1a15eb724aae ("btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Fri, 21 Jan 2022 15:44:39 +0000 (15:44 +0000)]
btrfs: fix use-after-free after failure to create a snapshot
At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and
then attach it to the transaction's list of pending snapshots. After that
we call btrfs_commit_transaction(), and if that returns an error we jump
to 'fail' label, where we kfree() the pending snapshot structure. This can
result in a later use-after-free of the pending snapshot:
1) We allocated the pending snapshot and added it to the transaction's
list of pending snapshots;
2) We call btrfs_commit_transaction(), and it fails either at the first
call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups().
In both cases, we don't abort the transaction and we release our
transaction handle. We jump to the 'fail' label and free the pending
snapshot structure. We return with the pending snapshot still in the
transaction's list;
3) Another task commits the transaction. This time there's no error at
all, and then during the transaction commit it accesses a pointer
to the pending snapshot structure that the snapshot creation task
has already freed, resulting in a user-after-free.
This issue could actually be detected by smatch, which produced the
following warning:
fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list
So fix this by not having the snapshot creation ioctl directly add the
pending snapshot to the transaction's list. Instead add the pending
snapshot to the transaction handle, and then at btrfs_commit_transaction()
we add the snapshot to the list only when we can guarantee that any error
returned after that point will result in a transaction abort, in which
case the ioctl code can safely free the pending snapshot and no one can
access it anymore.
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Su Yue [Fri, 21 Jan 2022 09:33:35 +0000 (17:33 +0800)]
btrfs: tree-checker: check item_size for dev_item
Check item size before accessing the device item to avoid out of bound
access, similar to inode_item check.
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Su Yue [Fri, 21 Jan 2022 09:33:34 +0000 (17:33 +0800)]
btrfs: tree-checker: check item_size for inode_item
while mounting the crafted image, out-of-bounds access happens:
[350.429619] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
[350.429636] index
1048096 is out of range for type 'page *[16]'
[350.429650] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4 #1
[350.429652] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[350.429653] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
[350.429772] Call Trace:
[350.429774] <TASK>
[350.429776] dump_stack_lvl+0x47/0x5c
[350.429780] ubsan_epilogue+0x5/0x50
[350.429786] __ubsan_handle_out_of_bounds+0x66/0x70
[350.429791] btrfs_get_16+0xfd/0x120 [btrfs]
[350.429832] check_leaf+0x754/0x1a40 [btrfs]
[350.429874] ? filemap_read+0x34a/0x390
[350.429878] ? load_balance+0x175/0xfc0
[350.429881] validate_extent_buffer+0x244/0x310 [btrfs]
[350.429911] btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
[350.429935] end_bio_extent_readpage+0x3af/0x850 [btrfs]
[350.429969] ? newidle_balance+0x259/0x480
[350.429972] end_workqueue_fn+0x29/0x40 [btrfs]
[350.429995] btrfs_work_helper+0x71/0x330 [btrfs]
[350.430030] ? __schedule+0x2fb/0xa40
[350.430033] process_one_work+0x1f6/0x400
[350.430035] ? process_one_work+0x400/0x400
[350.430036] worker_thread+0x2d/0x3d0
[350.430037] ? process_one_work+0x400/0x400
[350.430038] kthread+0x165/0x190
[350.430041] ? set_kthread_struct+0x40/0x40
[350.430043] ret_from_fork+0x1f/0x30
[350.430047] </TASK>
[350.430077] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start
20975616 member offset
4293005178 size 2
check_leaf() is checking the leaf:
corrupt leaf: root=4 block=
29396992 slot=1, bad key order, prev (
16140901064495857664 1 0) current (1 204
12582912)
leaf
29396992 items 6 free space 3565 generation 6 owner DEV_TREE
leaf
29396992 flags 0x1(WRITTEN) backref revision 1
fs uuid
a62e00e8-e94e-4200-8217-
12444de93c2e
chunk uuid
cecbd0f7-9ca0-441e-ae9f-
f782f9732bd8
item 0 key (
16140901064495857664 INODE_ITEM 0) itemoff 3955 itemsize 40
generation 0 transid 0 size 0 nbytes
17592186044416
block group 0 mode 52667 links 33 uid 0 gid
2104132511 rdev
94223634821136
sequence 100305 flags 0x2409000(none)
atime 0.0 (1970-01-01 08:00:00)
ctime
2973280098083405823.
4294967295 (-
269783007-01-01 21:37:03)
mtime
18446744071572723616.
4026825121 (1902-04-16 12:40:00)
otime
9249929404488876031.
4294967295 (
622322949-04-16 04:25:58)
item 1 key (1 DEV_EXTENT
12582912) itemoff 3907 itemsize 48
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset
12582912 length
8388608
chunk_tree_uuid
cecbd0f7-9ca0-441e-ae9f-
f782f9732bd8
The corrupted leaf of device tree has an inode item. The leaf passed
checksum and others checks in validate_extent_buffer until check_leaf_item().
Because of the key type BTRFS_INODE_ITEM, check_inode_item() is called even we
are in the device tree. Since the
item offset + sizeof(struct btrfs_inode_item) > eb->len, out-of-bounds access
is triggered.
The item end vs leaf boundary check has been done before
check_leaf_item(), so fix it by checking item size in check_inode_item()
before access of the inode item in extent buffer.
Other check functions except check_dev_item() in check_leaf_item()
have their item size checks.
The commit for check_dev_item() is followed.
No regression observed during running fstests.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
CC: stable@vger.kernel.org # 5.10+
CC: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Shin'ichiro Kawasaki [Thu, 20 Jan 2022 11:09:16 +0000 (20:09 +0900)]
btrfs: fix deadlock between quota disable and qgroup rescan worker
Quota disable ioctl starts a transaction before waiting for the qgroup
rescan worker completes. However, this wait can be infinite and results
in deadlock because of circular dependency among the quota disable
ioctl, the qgroup rescan worker and the other task with transaction such
as block group relocation task.
The deadlock happens with the steps following:
1) Task A calls ioctl to disable quota. It starts a transaction and
waits for qgroup rescan worker completes.
2) Task B such as block group relocation task starts a transaction and
joins to the transaction that task A started. Then task B commits to
the transaction. In this commit, task B waits for a commit by task A.
3) Task C as the qgroup rescan worker starts its job and starts a
transaction. In this transaction start, task C waits for completion
of the transaction that task A started and task B committed.
This deadlock was found with fstests test case btrfs/115 and a zoned
null_blk device. The test case enables and disables quota, and the
block group reclaim was triggered during the quota disable by chance.
The deadlock was also observed by running quota enable and disable in
parallel with 'btrfs balance' command on regular null_blk devices.
An example report of the deadlock:
[372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds.
[372.479944] Not tainted 5.16.0-rc8 #7
[372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[372.493898] task:kworker/u16:6 state:D stack: 0 pid: 103 ppid: 2 flags:0x00004000
[372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs]
[372.510782] Call Trace:
[372.514092] <TASK>
[372.521684] __schedule+0xb56/0x4850
[372.530104] ? io_schedule_timeout+0x190/0x190
[372.538842] ? lockdep_hardirqs_on+0x7e/0x100
[372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[372.555591] schedule+0xe0/0x270
[372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs]
[372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
[372.578875] ? free_unref_page+0x3f2/0x650
[372.585484] ? finish_wait+0x270/0x270
[372.591594] ? release_extent_buffer+0x224/0x420 [btrfs]
[372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs]
[372.607157] ? lock_release+0x3a9/0x6d0
[372.613054] ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs]
[372.620960] ? do_raw_spin_lock+0x11e/0x250
[372.627137] ? rwlock_bug.part.0+0x90/0x90
[372.633215] ? lock_is_held_type+0xe4/0x140
[372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs]
[372.646268] process_one_work+0x7e9/0x1320
[372.652321] ? lock_release+0x6d0/0x6d0
[372.658081] ? pwq_dec_nr_in_flight+0x230/0x230
[372.664513] ? rwlock_bug.part.0+0x90/0x90
[372.670529] worker_thread+0x59e/0xf90
[372.676172] ? process_one_work+0x1320/0x1320
[372.682440] kthread+0x3b9/0x490
[372.687550] ? _raw_spin_unlock_irq+0x24/0x50
[372.693811] ? set_kthread_struct+0x100/0x100
[372.700052] ret_from_fork+0x22/0x30
[372.705517] </TASK>
[372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds.
[372.729827] Not tainted 5.16.0-rc8 #7
[372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[372.767106] task:btrfs-transacti state:D stack: 0 pid: 2347 ppid: 2 flags:0x00004000
[372.787776] Call Trace:
[372.801652] <TASK>
[372.812961] __schedule+0xb56/0x4850
[372.830011] ? io_schedule_timeout+0x190/0x190
[372.852547] ? lockdep_hardirqs_on+0x7e/0x100
[372.871761] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[372.886792] schedule+0xe0/0x270
[372.901685] wait_current_trans+0x22c/0x310 [btrfs]
[372.919743] ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs]
[372.938923] ? finish_wait+0x270/0x270
[372.959085] ? join_transaction+0xc75/0xe30 [btrfs]
[372.977706] start_transaction+0x938/0x10a0 [btrfs]
[372.997168] transaction_kthread+0x19d/0x3c0 [btrfs]
[373.013021] ? btrfs_cleanup_transaction.isra.0+0xfc0/0xfc0 [btrfs]
[373.031678] kthread+0x3b9/0x490
[373.047420] ? _raw_spin_unlock_irq+0x24/0x50
[373.064645] ? set_kthread_struct+0x100/0x100
[373.078571] ret_from_fork+0x22/0x30
[373.091197] </TASK>
[373.105611] INFO: task btrfs:3145 blocked for more than 123 seconds.
[373.114147] Not tainted 5.16.0-rc8 #7
[373.120401] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[373.130393] task:btrfs state:D stack: 0 pid: 3145 ppid: 3141 flags:0x00004000
[373.140998] Call Trace:
[373.145501] <TASK>
[373.149654] __schedule+0xb56/0x4850
[373.155306] ? io_schedule_timeout+0x190/0x190
[373.161965] ? lockdep_hardirqs_on+0x7e/0x100
[373.168469] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[373.175468] schedule+0xe0/0x270
[373.180814] wait_for_commit+0x104/0x150 [btrfs]
[373.187643] ? test_and_set_bit+0x20/0x20 [btrfs]
[373.194772] ? kmem_cache_free+0x124/0x550
[373.201191] ? btrfs_put_transaction+0x69/0x3d0 [btrfs]
[373.208738] ? finish_wait+0x270/0x270
[373.214704] ? __btrfs_end_transaction+0x347/0x7b0 [btrfs]
[373.222342] btrfs_commit_transaction+0x44d/0x2610 [btrfs]
[373.230233] ? join_transaction+0x255/0xe30 [btrfs]
[373.237334] ? btrfs_record_root_in_trans+0x4d/0x170 [btrfs]
[373.245251] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
[373.253296] relocate_block_group+0x105/0xc20 [btrfs]
[373.260533] ? mutex_lock_io_nested+0x1270/0x1270
[373.267516] ? btrfs_wait_nocow_writers+0x85/0x180 [btrfs]
[373.275155] ? merge_reloc_roots+0x710/0x710 [btrfs]
[373.283602] ? btrfs_wait_ordered_extents+0xd30/0xd30 [btrfs]
[373.291934] ? kmem_cache_free+0x124/0x550
[373.298180] btrfs_relocate_block_group+0x35c/0x930 [btrfs]
[373.306047] btrfs_relocate_chunk+0x85/0x210 [btrfs]
[373.313229] btrfs_balance+0x12f4/0x2d20 [btrfs]
[373.320227] ? lock_release+0x3a9/0x6d0
[373.326206] ? btrfs_relocate_chunk+0x210/0x210 [btrfs]
[373.333591] ? lock_is_held_type+0xe4/0x140
[373.340031] ? rcu_read_lock_sched_held+0x3f/0x70
[373.346910] btrfs_ioctl_balance+0x548/0x700 [btrfs]
[373.354207] btrfs_ioctl+0x7f2/0x71b0 [btrfs]
[373.360774] ? lockdep_hardirqs_on_prepare+0x410/0x410
[373.367957] ? lockdep_hardirqs_on_prepare+0x410/0x410
[373.375327] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
[373.383841] ? find_held_lock+0x2c/0x110
[373.389993] ? lock_release+0x3a9/0x6d0
[373.395828] ? mntput_no_expire+0xf7/0xad0
[373.402083] ? lock_is_held_type+0xe4/0x140
[373.408249] ? vfs_fileattr_set+0x9f0/0x9f0
[373.414486] ? selinux_file_ioctl+0x349/0x4e0
[373.420938] ? trace_raw_output_lock+0xb4/0xe0
[373.427442] ? selinux_inode_getsecctx+0x80/0x80
[373.434224] ? lockdep_hardirqs_on+0x7e/0x100
[373.440660] ? force_qs_rnp+0x2a0/0x6b0
[373.446534] ? lock_is_held_type+0x9b/0x140
[373.452763] ? __blkcg_punt_bio_submit+0x1b0/0x1b0
[373.459732] ? security_file_ioctl+0x50/0x90
[373.466089] __x64_sys_ioctl+0x127/0x190
[373.472022] do_syscall_64+0x3b/0x90
[373.477513] entry_SYSCALL_64_after_hwframe+0x44/0xae
[373.484823] RIP: 0033:0x7f8f4af7e2bb
[373.490493] RSP: 002b:
00007ffcbf936178 EFLAGS:
00000246 ORIG_RAX:
0000000000000010
[373.500197] RAX:
ffffffffffffffda RBX:
0000000000000003 RCX:
00007f8f4af7e2bb
[373.509451] RDX:
00007ffcbf936220 RSI:
00000000c4009420 RDI:
0000000000000003
[373.518659] RBP:
00007ffcbf93774a R08:
0000000000000013 R09:
00007f8f4b02d4e0
[373.527872] R10:
00007f8f4ae87740 R11:
0000000000000246 R12:
0000000000000001
[373.537222] R13:
00007ffcbf936220 R14:
0000000000000000 R15:
0000000000000002
[373.546506] </TASK>
[373.550878] INFO: task btrfs:3146 blocked for more than 123 seconds.
[373.559383] Not tainted 5.16.0-rc8 #7
[373.565748] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[373.575748] task:btrfs state:D stack: 0 pid: 3146 ppid: 2168 flags:0x00000000
[373.586314] Call Trace:
[373.590846] <TASK>
[373.595121] __schedule+0xb56/0x4850
[373.600901] ? __lock_acquire+0x23db/0x5030
[373.607176] ? io_schedule_timeout+0x190/0x190
[373.613954] schedule+0xe0/0x270
[373.619157] schedule_timeout+0x168/0x220
[373.625170] ? usleep_range_state+0x150/0x150
[373.631653] ? mark_held_locks+0x9e/0xe0
[373.637767] ? do_raw_spin_lock+0x11e/0x250
[373.643993] ? lockdep_hardirqs_on_prepare+0x17b/0x410
[373.651267] ? _raw_spin_unlock_irq+0x24/0x50
[373.657677] ? lockdep_hardirqs_on+0x7e/0x100
[373.664103] wait_for_completion+0x163/0x250
[373.670437] ? bit_wait_timeout+0x160/0x160
[373.676585] btrfs_quota_disable+0x176/0x9a0 [btrfs]
[373.683979] ? btrfs_quota_enable+0x12f0/0x12f0 [btrfs]
[373.691340] ? down_write+0xd0/0x130
[373.696880] ? down_write_killable+0x150/0x150
[373.703352] btrfs_ioctl+0x3945/0x71b0 [btrfs]
[373.710061] ? find_held_lock+0x2c/0x110
[373.716192] ? lock_release+0x3a9/0x6d0
[373.722047] ? __handle_mm_fault+0x23cd/0x3050
[373.728486] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
[373.737032] ? set_pte+0x6a/0x90
[373.742271] ? do_raw_spin_unlock+0x55/0x1f0
[373.748506] ? lock_is_held_type+0xe4/0x140
[373.754792] ? vfs_fileattr_set+0x9f0/0x9f0
[373.761083] ? selinux_file_ioctl+0x349/0x4e0
[373.767521] ? selinux_inode_getsecctx+0x80/0x80
[373.774247] ? __up_read+0x182/0x6e0
[373.780026] ? count_memcg_events.constprop.0+0x46/0x60
[373.787281] ? up_write+0x460/0x460
[373.792932] ? security_file_ioctl+0x50/0x90
[373.799232] __x64_sys_ioctl+0x127/0x190
[373.805237] do_syscall_64+0x3b/0x90
[373.810947] entry_SYSCALL_64_after_hwframe+0x44/0xae
[373.818102] RIP: 0033:0x7f1383ea02bb
[373.823847] RSP: 002b:
00007fffeb4d71f8 EFLAGS:
00000202 ORIG_RAX:
0000000000000010
[373.833641] RAX:
ffffffffffffffda RBX:
0000000000000000 RCX:
00007f1383ea02bb
[373.842961] RDX:
00007fffeb4d7210 RSI:
00000000c0109428 RDI:
0000000000000003
[373.852179] RBP:
0000000000000003 R08:
0000000000000003 R09:
0000000000000078
[373.861408] R10:
00007f1383daec78 R11:
0000000000000202 R12:
00007fffeb4d874a
[373.870647] R13:
0000000000493099 R14:
0000000000000001 R15:
0000000000000000
[373.879838] </TASK>
[373.884018]
Showing all locks held in the system:
[373.894250] 3 locks held by kworker/4:1/58:
[373.900356] 1 lock held by khungtaskd/63:
[373.906333] #0:
ffffffff8945ff60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260
[373.917307] 3 locks held by kworker/u16:6/103:
[373.923938] #0:
ffff888127b4f138 ((wq_completion)btrfs-qgroup-rescan){+.+.}-{0:0}, at: process_one_work+0x712/0x1320
[373.936555] #1:
ffff88810b817dd8 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x73f/0x1320
[373.951109] #2:
ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_qgroup_rescan_worker+0x1f6/0x10c0 [btrfs]
[373.964027] 2 locks held by less/1803:
[373.969982] #0:
ffff88813ed56098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80
[373.981295] #1:
ffffc90000b3b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9e2/0x1060
[373.992969] 1 lock held by btrfs-transacti/2347:
[373.999893] #0:
ffff88813d4887a8 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0xe3/0x3c0 [btrfs]
[374.015872] 3 locks held by btrfs/3145:
[374.022298] #0:
ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl_balance+0xc3/0x700 [btrfs]
[374.034456] #1:
ffff88813d48a0a0 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0xfe5/0x2d20 [btrfs]
[374.047646] #2:
ffff88813d488838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x354/0x930 [btrfs]
[374.063295] 4 locks held by btrfs/3146:
[374.069647] #0:
ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl+0x38b1/0x71b0 [btrfs]
[374.081601] #1:
ffff88813d488bb8 (&fs_info->subvol_sem){+.+.}-{3:3}, at: btrfs_ioctl+0x38fd/0x71b0 [btrfs]
[374.094283] #2:
ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_disable+0xc8/0x9a0 [btrfs]
[374.106885] #3:
ffff88813d489800 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_disable+0xd5/0x9a0 [btrfs]
[374.126780] =============================================
To avoid the deadlock, wait for the qgroup rescan worker to complete
before starting the transaction for the quota disable ioctl. Clear
BTRFS_FS_QUOTA_ENABLE flag before the wait and the transaction to
request the worker to complete. On transaction start failure, set the
BTRFS_FS_QUOTA_ENABLE flag again. These BTRFS_FS_QUOTA_ENABLE flag
changes can be done safely since the function btrfs_quota_disable is not
called concurrently because of fs_info->subvol_sem.
Also check the BTRFS_FS_QUOTA_ENABLE flag in qgroup_rescan_init to avoid
another qgroup rescan worker to start after the previous qgroup worker
completed.
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 16 Dec 2021 11:47:35 +0000 (19:47 +0800)]
btrfs: don't start transaction for scrub if the fs is mounted read-only
[BUG]
The following super simple script would crash btrfs at unmount time, if
CONFIG_BTRFS_ASSERT() is set.
mkfs.btrfs -f $dev
mount $dev $mnt
xfs_io -f -c "pwrite 0 4k" $mnt/file
umount $mnt
mount -r ro $dev $mnt
btrfs scrub start -Br $mnt
umount $mnt
This will trigger the following ASSERT() introduced by commit
0a31daa4b602 ("btrfs: add assertion for empty list of transactions at
late stage of umount").
That patch is definitely not the cause, it just makes enough noise for
developers.
[CAUSE]
We will start transaction for the following call chain during scrub:
scrub_enumerate_chunks()
|- btrfs_inc_block_group_ro()
|- btrfs_join_transaction()
However for RO mount, there is no running transaction at all, thus
btrfs_join_transaction() will start a new transaction.
Furthermore, since it's read-only mount, btrfs_sync_fs() will not call
btrfs_commit_super() to commit the new but empty transaction.
And leads to the ASSERT().
The bug has been there for a long time. Only the new ASSERT() makes it
noisy enough to be noticed.
[FIX]
For read-only scrub on read-only mount, there is no need to start a
transaction nor to allocate new chunks in btrfs_inc_block_group_ro().
Just do extra read-only mount check in btrfs_inc_block_group_ro(), and
if it's read-only, skip all chunk allocation and go inc_block_group_ro()
directly.
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 20 Jan 2022 17:41:17 +0000 (17:41 +0000)]
btrfs: update writeback index when starting defrag
When starting a defrag, we should update the writeback index of the
inode's mapping in case it currently has a value beyond the start of the
range we are defragging. This can help performance and often result in
getting less extents after writeback - for e.g., if the current value
of the writeback index sits somewhere in the middle of a range that
gets dirty by the defrag, then after writeback we can get two smaller
extents instead of a single, larger extent.
We used to have this before the refactoring in 5.16, but it was removed
without any reason to do so. Originally it was added in kernel 3.1, by
commit
2a0f7f5769992b ("Btrfs: fix recursive auto-defrag"), in order to
fix a loop with autodefrag resulting in dirtying and writing pages over
and over, but some testing on current code did not show that happening,
at least with the test described in that commit.
So add back the behaviour, as at the very least it is a nice to have
optimization.
Fixes:
7b508037d4cac3 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 20 Jan 2022 17:11:52 +0000 (17:11 +0000)]
btrfs: add back missing dirty page rate limiting to defrag
A defrag operation can dirty a lot of pages, specially if operating on
the entire file or a large file range. Any task dirtying pages should
periodically call balance_dirty_pages_ratelimited(), as stated in that
function's comments, otherwise they can leave too many dirty pages in
the system. This is what we did before the refactoring in 5.16, and
it should have remained, just like in the buffered write path and
relocation. So restore that behaviour.
Fixes:
7b508037d4cac3 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 20 Jan 2022 14:27:56 +0000 (14:27 +0000)]
btrfs: fix deadlock when reserving space during defrag
When defragging we can end up collecting a range for defrag that has
already pages under delalloc (dirty), as long as the respective extent
map for their range is not mapped to a hole, a prealloc extent or
the extent map is from an old generation.
Most of the time that is harmless from a functional perspective at
least, however it can result in a deadlock:
1) At defrag_collect_targets() we find an extent map that meets all
requirements but there's delalloc for the range it covers, and we add
its range to list of ranges to defrag;
2) The defrag_collect_targets() function is called at defrag_one_range(),
after it locked a range that overlaps the range of the extent map;
3) At defrag_one_range(), while the range is still locked, we call
defrag_one_locked_target() for the range associated to the extent
map we collected at step 1);
4) Then finally at defrag_one_locked_target() we do a call to
btrfs_delalloc_reserve_space(), which will reserve data and metadata
space. If the space reservations can not be satisfied right away, the
flusher might be kicked in and start flushing delalloc and wait for
the respective ordered extents to complete. If this happens we will
deadlock, because both flushing delalloc and finishing an ordered
extent, requires locking the range in the inode's io tree, which was
already locked at defrag_collect_targets().
So fix this by skipping extent maps for which there's already delalloc.
Fixes:
eb793cf857828d ("btrfs: defrag: introduce helper to collect target file extents")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 18 Jan 2022 11:53:52 +0000 (19:53 +0800)]
btrfs: defrag: properly update range->start for autodefrag
[BUG]
After commit
7b508037d4ca ("btrfs: defrag: use defrag_one_cluster() to
implement btrfs_defrag_file()") autodefrag no longer properly re-defrag
the file from previously finished location.
[CAUSE]
The recent refactoring of defrag only focuses on defrag ioctl subpage
support, doesn't take autodefrag into consideration.
There are two problems involved which prevents autodefrag to restart its
scan:
- No range.start update
Previously when one defrag target is found, range->start will be
updated to indicate where next search should start from.
But now btrfs_defrag_file() doesn't update it anymore, making all
autodefrag to rescan from file offset 0.
This would also make autodefrag to mark the same range dirty again and
again, causing extra IO.
- No proper quick exit for defrag_one_cluster()
Currently if we reached or exceed @max_sectors limit, we just exit
defrag_one_cluster(), and let next defrag_one_cluster() call to do a
quick exit.
This makes @cur increase, thus no way to properly know which range is
defragged and which range is skipped.
[FIX]
The fix involves two modifications:
- Update range->start to next cluster start
This is a little different from the old behavior.
Previously range->start is updated to the next defrag target.
But in the end, the behavior should still be pretty much the same,
as now we skip to next defrag target inside btrfs_defrag_file().
Thus if auto-defrag determines to re-scan, then we still do the skip,
just at a different timing.
- Make defrag_one_cluster() to return >0 to indicate a quick exit
So that btrfs_defrag_file() can also do a quick exit, without
increasing @cur to the range end, and re-use @cur to update
@range->start.
- Add comment for btrfs_defrag_file() to mention the range->start update
Currently only autodefrag utilize this behavior, as defrag ioctl won't
set @max_to_defrag parameter, thus unless interrupted it will always
try to defrag the whole range.
Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes:
7b508037d4ca ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 18 Jan 2022 07:19:04 +0000 (15:19 +0800)]
btrfs: defrag: fix wrong number of defragged sectors
[BUG]
There are users using autodefrag mount option reporting obvious increase
in IO:
> If I compare the write average (in total, I don't have it per process)
> when taking idle periods on the same machine:
> Linux 5.16:
> without autodefrag: ~ 10KiB/s
> with autodefrag: between 1 and 2MiB/s.
>
> Linux 5.15:
> with autodefrag:~ 10KiB/s (around the same as without
> autodefrag on 5.16)
[CAUSE]
When autodefrag mount option is enabled, btrfs_defrag_file() will be
called with @max_sectors = BTRFS_DEFRAG_BATCH (1024) to limit how many
sectors we can defrag in one try.
And then use the number of sectors defragged to determine if we need to
re-defrag.
But commit
b18c3ab2343d ("btrfs: defrag: introduce helper to defrag one
cluster") uses wrong unit to increase @sectors_defragged, which should
be in unit of sector, not byte.
This means, if we have defragged any sector, then @sectors_defragged
will be >= sectorsize (normally 4096), which is larger than
BTRFS_DEFRAG_BATCH.
This makes the @max_sectors check in defrag_one_cluster() to underflow,
rendering the whole @max_sectors check useless.
Thus causing way more IO for autodefrag mount options, as now there is
no limit on how many sectors can really be defragged.
[FIX]
Fix the problems by:
- Use sector as unit when increasing @sectors_defragged
- Include @sectors_defragged > @max_sectors case to break the loop
- Add extra comment on the return value of btrfs_defrag_file()
Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Fixes:
b18c3ab2343d ("btrfs: defrag: introduce helper to defrag one cluster")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 18 Jan 2022 13:43:31 +0000 (13:43 +0000)]
btrfs: allow defrag to be interruptible
During defrag, at btrfs_defrag_file(), we have this loop that iterates
over a file range in steps no larger than 256K subranges. If the range
is too long, there's no way to interrupt it. So make the loop check in
each iteration if there's signal pending, and if there is, break and
return -AGAIN to userspace.
Before kernel 5.16, we used to allow defrag to be cancelled through a
signal, but that was lost with commit
7b508037d4cac3 ("btrfs: defrag:
use defrag_one_cluster() to implement btrfs_defrag_file()").
This change adds back the possibility to cancel a defrag with a signal
and keeps the same semantics, returning -EAGAIN to user space (and not
the usually more expected -EINTR).
This is also motivated by a recent bug on 5.16 where defragging a 1 byte
file resulted in iterating from file range 0 to (u64)-1, as hitting the
bug triggered a too long loop, basically requiring one to reboot the
machine, as it was not possible to cancel defrag.
Fixes:
7b508037d4cac3 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 17 Jan 2022 16:28:29 +0000 (16:28 +0000)]
btrfs: fix too long loop when defragging a 1 byte file
When attempting to defrag a file with a single byte, we can end up in a
too long loop, which is nearly infinite because at btrfs_defrag_file()
we end up with the variable last_byte assigned with a value of
18446744073709551615 (which is (u64)-1). The problem comes from the fact
we end up doing:
last_byte = round_up(last_byte, fs_info->sectorsize) - 1;
So if last_byte was assigned 0, which is i_size - 1, we underflow and
end up with the value
18446744073709551615.
This is trivial to reproduce and the following script triggers it:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
echo -n "X" > $MNT/foobar
btrfs filesystem defragment $MNT/foobar
umount $MNT
So fix this by not decrementing last_byte by 1 before doing the sector
size round up. Also, to make it easier to follow, make the round up right
after computing last_byte.
Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Fixes:
7b508037d4cac3 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 16 Dec 2021 11:47:36 +0000 (19:47 +0800)]
btrfs: output more debug messages for uncommitted transaction
Print extra information about how many dirty bytes an uncommitted
has at the end of mount.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 16 Dec 2021 15:00:32 +0000 (15:00 +0000)]
btrfs: respect the max size in the header when activating swap file
If we extended the size of a swapfile after its header was created (by the
mkswap utility) and then try to activate it, we will map the entire file
when activating the swap file, instead of limiting to the max size defined
in the swap file's header.
Currently test case generic/643 from fstests fails because we do not
respect that size limit defined in the swap file's header.
So fix this by not mapping file ranges beyond the max size defined in the
swap header.
This is the same type of bug that iomap used to have, and was fixed in
commit
36ca7943ac18ae ("mm/swap: consider max pages in
iomap_swapfile_add_extent").
Fixes:
ed46ff3d423780 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-and-tested-by: Josef Bacik <josef@toxicpanda.com
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Yang Li [Mon, 20 Dec 2021 07:23:06 +0000 (15:23 +0800)]
btrfs: fix argument list that the kdoc format and script verified
The warnings were found by running scripts/kernel-doc, which is
caused by using 'make W=1'.
fs/btrfs/extent_io.c:3210: warning: Function parameter or member
'bio_ctrl' not described in 'btrfs_bio_add_page'
fs/btrfs/extent_io.c:3210: warning: Excess function parameter 'bio'
description in 'btrfs_bio_add_page'
fs/btrfs/extent_io.c:3210: warning: Excess function parameter
'prev_bio_flags' description in 'btrfs_bio_add_page'
fs/btrfs/space-info.c:1602: warning: Excess function parameter 'root'
description in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1602: warning: Function parameter or member
'fs_info' not described in 'btrfs_reserve_metadata_bytes'
Note: this is fixing only the warnings regarding parameter list, the
first line is not strictly conforming to the kdoc format as the btrfs
codebase does not stick to that and keeps the first line more free form
(because it's only for internal use).
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Su Yue [Mon, 27 Dec 2021 10:18:39 +0000 (18:18 +0800)]
btrfs: remove unnecessary parameter type from compression_decompress_bio
btrfs_decompress_bio, the only caller of compression_decompress_bio gets
type from @cb and passes it to compression_decompress_bio.
However, compression_decompress_bio can get compression type directly
from @cb.
So remove the parameter and access it through @cb. No functional
change.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 30 Dec 2021 08:45:13 +0000 (16:45 +0800)]
btrfs: selftests: dump extent io tree if extent-io-tree test failed
When code modifying extent-io-tree get modified and got that selftest
failed, it can take some time to pin down the cause.
To make it easier to expose the problem, dump the extent io tree if the
selftest failed.
This can save developers debug time, especially since the selftest we
can not use the trace events, thus have to manually add debug trace
points.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 15 Dec 2021 06:59:42 +0000 (14:59 +0800)]
btrfs: scrub: cleanup the argument list of scrub_stripe()
The argument list of btrfs_stripe() has similar problems of
scrub_chunk():
- Duplicated and ambiguous @base argument
Can be fetched from btrfs_block_group::bg.
- Ambiguous argument @length
It's again device extent length
- Ambiguous argument @num
The instinctive guess would be mirror number, but in fact it's stripe
index.
Fix it by:
- Remove @base parameter
- Rename @length to @dev_extent_len
- Rename @num to @stripe_index
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 15 Dec 2021 06:59:41 +0000 (14:59 +0800)]
btrfs: scrub: cleanup the argument list of scrub_chunk()
The argument list of scrub_chunk() has the following problems:
- Duplicated @chunk_offset
It is the same as btrfs_block_group::start.
- Confusing @length
The most instinctive guess is chunk length, and one may want to delete
it, but the truth is, it's the device extent length.
Fix this by:
- Remove @chunk_offset
Use btrfs_block_group::start instead.
- Rename @length to @dev_extent_len
Also rename the caller to remove the ambiguous naming.
- Rename @cache to @bg
The "_cache" suffix for btrfs_block_group has been removed for a while.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 14 Dec 2021 13:01:45 +0000 (21:01 +0800)]
btrfs: remove reada infrastructure
Currently there is only one user for btrfs metadata readahead, and
that's scrub.
But even for the single user, it's not providing the correct
functionality it needs, as scrub needs reada for commit root, which
current readahead can't provide. (Although it's pretty easy to add such
feature).
Despite this, there are some extra problems related to metadata
readahead:
- Duplicated feature with btrfs_path::reada
- Partly duplicated feature of btrfs_fs_info::buffer_radix
Btrfs already caches its metadata in buffer_radix, while readahead
tries to read the tree block no matter if it's already cached.
- Poor layer separation
Metadata readahead works kinda at device level.
This is definitely not the correct layer it should be, since metadata
is at btrfs logical address space, it should not bother device at all.
This brings extra chance for bugs to sneak in, while brings
unnecessary complexity.
- Dead code
In the very beginning of scrub.c we have #undef DEBUG, rendering all
the debug related code useless and unable to test.
Thus here I purpose to remove the metadata readahead mechanism
completely.
[BENCHMARK]
There is a full benchmark for the scrub performance difference using the
old btrfs_reada_add() and btrfs_path::reada.
For the worst case (no dirty metadata, slow HDD), there could be a 5%
performance drop for scrub.
For other cases (even SATA SSD), there is no distinguishable performance
difference.
The number is reported scrub speed, in MiB/s.
The resolution is limited by the reported duration, which only has a
resolution of 1 second.
Old New Diff
SSD 455.3 466.332 +2.42%
HDD 103.927 98.012 -5.69%
Comprehensive test methodology is in the cover letter of the patch.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 14 Dec 2021 13:01:44 +0000 (21:01 +0800)]
btrfs: scrub: use btrfs_path::reada for extent tree readahead
For scrub, we trigger two readaheads for two trees, extent tree to get
where to scrub, and csum tree to get the data checksum.
For csum tree we already trigger readahead in
btrfs_lookup_csums_range(), by setting path->reada.
But for extent tree we don't have any path based readahead.
Add the readahead for extent tree as well, so we can later remove the
btrfs_reada_add() based readahead.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 14 Dec 2021 13:01:43 +0000 (21:01 +0800)]
btrfs: scrub: remove the unnecessary path parameter for scrub_raid56_parity()
In function scrub_stripe() we allocated two btrfs_path's, one @path for
extent tree search and another @ppath for full stripe extent tree search
for RAID56.
This is totally umncessary, as the @ppath usage is completely inside
scrub_raid56_parity(), thus we can move the path allocation into
scrub_raid56_parity() completely.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 14 Dec 2021 13:39:39 +0000 (15:39 +0200)]
btrfs: refactor unlock_up
The purpose of this function is to unlock all nodes in a btrfs path
which are above 'lowest_unlock' and whose slot used is different than 0.
As such it used slightly awkward structure of 'if' as well as somewhat
cryptic "no_skip" control variable which denotes whether we should
check the current level of skipability or no.
This patch does the following (cosmetic) refactorings:
* Renames 'no_skip' to 'check_skip' and makes it a boolean. This
variable controls whether we are below the lowest_unlock/skip_level
levels.
* Consolidates the 2 conditions which warrant checking whether the
current level should be skipped under 1 common if (check_skip) branch,
this increase indentation level but is not critical.
* Consolidates the 'skip_level < i && i >= lowest_unlock' and
'i >= lowest_unlock && i > skip_level' condition into a common branch
since those are identical.
* Eliminates the local extent_buffer variable as in this case it doesn't
bring anything to function readability.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 13 Dec 2021 08:45:14 +0000 (08:45 +0000)]
btrfs: skip transaction commit after failure to create subvolume
At ioctl.c:create_subvol(), when we fail to create a subvolume we always
commit the transaction. In most cases this is a no-op, since all the error
paths, except for one, abort the transaction - the only exception is when
we fail to insert the new root item into the root tree, in that case we
don't abort the transaction because we didn't do anything that is
irreversible - however we end up committing the transaction which although
is not a functional problem, it adds unnecessary rotation of the backup
roots in the superblock and unnecessary work.
So change that to commit a transaction only when no error happened,
otherwise just call btrfs_end_transaction() to release our reference on
the transaction.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 7 Dec 2021 15:35:49 +0000 (00:35 +0900)]
btrfs: zoned: fix chunk allocation condition for zoned allocator
The ZNS specification defines a limit on the number of "active"
zones. That limit impose us to limit the number of block groups which
can be used for an allocation at the same time. Not to exceed the
limit, we reuse the existing active block groups as much as possible
when we can't activate any other zones without sacrificing an already
activated block group in commit
a85f05e59bc1 ("btrfs: zoned: avoid
chunk allocation if active block group has enough space").
However, the check is wrong in two ways. First, it checks the
condition for every raid index (ffe_ctl->index). Even if it reaches
the condition and "ffe_ctl->max_extent_size >=
ffe_ctl->min_alloc_size" is met, there can be other block groups
having enough space to hold ffe_ctl->num_bytes. (Actually, this won't
happen in the current zoned code as it only supports SINGLE
profile. But, it can happen once it enables other RAID types.)
Second, it checks the active zone availability depending on the
raid index. The raid index is just an index for
space_info->block_groups, so it has nothing to do with chunk allocation.
These mistakes are causing a faulty allocation in a certain
situation. Consider we are running zoned btrfs on a device whose
max_active_zone == 0 (no limit). And, suppose no block group have a
room to fit ffe_ctl->num_bytes but some room to meet
ffe_ctl->min_alloc_size (i.e. max_extent_size > num_bytes >=
min_alloc_size).
In this situation, the following occur:
- With SINGLE raid_index, it reaches the chunk allocation checking
code
- The check returns true because we can activate a new zone (no limit)
- But, before allocating the chunk, it iterates to the next raid index
(RAID5)
- Since there are no RAID5 block groups on zoned mode, it again
reaches the check code
- The check returns false because of btrfs_can_activate_zone()'s "if
(raid_index != BTRFS_RAID_SINGLE)" part
- That results in returning -ENOSPC without allocating a new chunk
As a result, we end up hitting -ENOSPC too early.
Move the check to the right place in the can_allocate_chunk() hook,
and do the active zone check depending on the allocation flag, not on
the raid index.
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 7 Dec 2021 15:35:48 +0000 (00:35 +0900)]
btrfs: add extent allocator hook to decide to allocate chunk or not
Introduce a new hook for an extent allocator policy. With the new
hook, a policy can decide to allocate a new block group or not. If
not, it will return -ENOSPC, so btrfs_reserve_extent() will cut the
allocation size in half and retry the allocation if min_alloc_size is
large enough.
The hook has a place holder and will be replaced with the real
implementation in the next patch.
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 7 Dec 2021 15:35:47 +0000 (00:35 +0900)]
btrfs: zoned: unset dedicated block group on allocation failure
Allocating an extent from a block group can fail for various reasons.
When an allocation from a dedicated block group (for tree-log or
relocation data) fails, we need to unregister it as a dedicated one so
that we can allocate a new block group for the dedicated one.
However, we are returning early when the block group in case it is
read-only, fully used, or not be able to activate the zone. As a result,
we keep the non-usable block group as a dedicated one, leading to
further allocation failure. With many block groups, the allocator will
iterate hopeless loop to find a free extent, results in a hung task.
Fix the issue by delaying the return and doing the proper cleanups.
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Tue, 7 Dec 2021 14:28:37 +0000 (06:28 -0800)]
btrfs: zoned: drop redundant check for REQ_OP_ZONE_APPEND and btrfs_is_zoned
REQ_OP_ZONE_APPEND can only work on zoned devices, so it is redundant to
check if the filesystem is zoned when REQ_OP_ZONE_APPEND is set as the
bio's bio_op.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Tue, 7 Dec 2021 14:28:36 +0000 (06:28 -0800)]
btrfs: zoned: sink zone check into btrfs_repair_one_zone
Sink zone check into btrfs_repair_one_zone() so we don't need to do it
in all callers.
Also as btrfs_repair_one_zone() doesn't return a sensible error, make it
a boolean function and return false in case it got called on a non-zoned
filesystem and true on a zoned filesystem.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Tue, 7 Dec 2021 14:28:35 +0000 (06:28 -0800)]
btrfs: zoned: simplify btrfs_check_meta_write_pointer
btrfs_check_meta_write_pointer() will always be called with a NULL
'cache_ret' argument.
As there's no need to check if we have a valid block_group passed in
remove these checks.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Tue, 7 Dec 2021 14:28:34 +0000 (06:28 -0800)]
btrfs: zoned: encapsulate inode locking for zoned relocation
Encapsulate the inode lock needed for serializing the data relocation
writes on a zoned filesystem into a helper.
This streamlines the code reading flow and hides special casing for
zoned filesystems.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Thu, 21 Oct 2021 15:31:17 +0000 (23:31 +0800)]
btrfs: sysfs: add devinfo/fsid to retrieve actual fsid from the device
In the case of the seed device, the fsid can be different from the mounted
sprout fsid. The userland has to read the device superblock to know the
fsid but, that idea fails if the device is missing. So add a sysfs
interface devinfo/<devid>/fsid to show the fsid of the device.
For example:
$ cd /sys/fs/btrfs/
b10b02a5-f9de-4276-b9e8-
2bfd09a578a8
$ cat devinfo/1/fsid
c44d771f-639d-4df3-99ec-
5bc7ad2af93b
$ cat devinfo/3/fsid
b10b02a5-f9de-4276-b9e8-
2bfd09a578a8
Though it's related to seeding, the name of the sysfs file is plain fsid as it
matches what blkid says. A path to the device's fsid will aid scripting.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Thu, 2 Dec 2021 20:34:32 +0000 (15:34 -0500)]
btrfs: reserve extra space for the free space tree
Filipe reported a problem where sometimes he'd get an ENOSPC abort when
running delayed refs with generic/619 and the free space tree enabled.
This is partly because we do not reserve space for modifying the free
space tree, nor do we have a block rsv associated with that tree.
The delayed_refs_rsv tracks the amount of space required to run delayed
refs. This means 1 modification means 1 change to the extent root.
With the free space tree this turns into 2 changes, because modifying 1
extent means updating the extent tree and potentially updating the free
space tree to either remove that entry or add the free space. Thus if
we have the FST enabled, simply double the reservation size for our
modification.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Thu, 2 Dec 2021 20:34:31 +0000 (15:34 -0500)]
btrfs: include the free space tree in the global rsv minimum calculation
Filipe reported a problem where generic/619 was failing with an ENOSPC
abort while running delayed refs, like the following
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 3 PID: 522920 at fs/btrfs/free-space-tree.c:1049 add_to_free_space_tree+0xe5/0x110 [btrfs]
CPU: 3 PID: 522920 Comm: kworker/u16:19 Tainted: G W 5.16.0-rc2-btrfs-next-106 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
RIP: 0010:add_to_free_space_tree+0xe5/0x110 [btrfs]
RSP: 0000:
ffffa65087fb7b20 EFLAGS:
00010282
RAX:
0000000000000000 RBX:
0000000000001000 RCX:
0000000000000000
RDX:
0000000000000001 RSI:
ffffffff9131eeaa RDI:
00000000ffffffff
RBP:
ffff8d62e26481b8 R08:
ffffffff9ad97ce0 R09:
0000000000000001
R10:
0000000000000000 R11:
0000000000000001 R12:
00000000ffffffe4
R13:
ffff8d61c25fe688 R14:
ffff8d61ebd88800 R15:
ffff8d61ebd88a90
FS:
0000000000000000(0000) GS:
ffff8d64ed400000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007fa46a8b1000 CR3:
0000000148d18003 CR4:
0000000000370ee0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
<TASK>
__btrfs_free_extent+0x516/0x950 [btrfs]
__btrfs_run_delayed_refs+0x2b1/0x1250 [btrfs]
btrfs_run_delayed_refs+0x86/0x210 [btrfs]
flush_space+0x403/0x630 [btrfs]
? call_rcu_tasks_generic+0x50/0x80
? lock_release+0x223/0x4a0
? btrfs_get_alloc_profile+0xb5/0x290 [btrfs]
? do_raw_spin_unlock+0x4b/0xa0
btrfs_async_reclaim_metadata_space+0x139/0x320 [btrfs]
process_one_work+0x24c/0x5b0
worker_thread+0x55/0x3c0
? process_one_work+0x5b0/0x5b0
kthread+0x17c/0x1a0
? set_kthread_struct+0x40/0x40
ret_from_fork+0x22/0x30
There's a couple of reasons for this, but in generic/619's case the
largest reason is because it is a very small file system, ad we do not
reserve enough space for the global reserve.
With the free space tree we now have the free space tree that we need to
modify when running delayed refs. This means we need the global reserve
to take this into account when it calculates the minimum size it needs
to be. This is especially important for very small file systems.
Fix this by adjusting the minimum global block rsv size math to include
the size of the free space tree when calculating the size.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Mon, 6 Dec 2021 05:52:58 +0000 (13:52 +0800)]
btrfs: scrub: merge SCRUB_PAGES_PER_RD_BIO and SCRUB_PAGES_PER_WR_BIO
These two values were introduced in commit
ff023aac3119 ("Btrfs: add code
to scrub to copy read data to another disk") as an optimization.
But the truth is, block layer scheduler can do whatever it wants to
merge/split bios to improve performance.
Doing such "optimization" is not really going to affect much, especially
considering how good current block layer optimizations are doing.
Remove such old and immature optimization from our code.
Since we're here, also change BUG_ON()s using these two macros to use
ASSERT()s.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Mon, 6 Dec 2021 05:52:57 +0000 (13:52 +0800)]
btrfs: update SCRUB_MAX_PAGES_PER_BLOCK
Use BTRFS_MAX_METADATA_BLOCKSIZE and SZ_4K (minimal sectorsize) to
calculate this value.
And remove one stale comment on the value, in fact with recent subpage
support, BTRFS_MAX_METADATA_BLOCKSIZE * PAGE_SIZE is already beyond
BTRFS_STRIPE_LEN, just we don't use the full page.
Also since we're here, update the BUG_ON() related to
SCRUB_MAX_PAGES_PER_BLOCK to ASSERT().
As those ASSERT() are really only for developers to catch early obvious
bugs, not to let end users suffer.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:20 +0000 (17:18 -0500)]
btrfs: do not check -EAGAIN when truncating inodes in the log root
We only throttle the btrfs_truncate_inode_items if the root is
SHAREABLE, which isn't set on the log root, which means this loop is
unnecessary.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:19 +0000 (17:18 -0500)]
btrfs: make should_throttle loop local in btrfs_truncate_inode_items
We reset this bool on every loop through the truncate loop, make this
variable local to the loop.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:18 +0000 (17:18 -0500)]
btrfs: combine extra if statements in btrfs_truncate_inode_items
We have
if (del_item)
// do something
else
// something else
if (del_item)
// do yet another thing
else
// something else entirely
back to back in btrfs_truncate_inode_items, collapse these two sets of
if statements into one.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:17 +0000 (17:18 -0500)]
btrfs: convert BUG() for pending_del_nr into an ASSERT
This is a logic correctness check, convert it into an ASSERT() instead
of a BUG().
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:16 +0000 (17:18 -0500)]
btrfs: convert BUG_ON() in btrfs_truncate_inode_items to ASSERT
We have a correctness BUG_ON() in btrfs_truncate_inode_items to make
sure that we're always using min_type == BTRFS_EXTENT_DATA_KEY if
new_size is > 0. Convert this to an ASSERT.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:15 +0000 (17:18 -0500)]
btrfs: add inode to truncate control
In the future we're going to want to use btrfs_truncate_inode_items
without looking up the associated inode. In order to accommodate this
add the inode to btrfs_truncate_control and handle the case where
control->inode is NULL appropriately. This is fairly straightforward,
we simply need to add a helper for the trace points, as the file extent
map update is controlled by a flag on btrfs_truncate_control.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:14 +0000 (17:18 -0500)]
btrfs: pass the ino via truncate control
In the future we are going to want to truncate inode items without
needing to have an btrfs_inode to pass in, so add ino to the
btrfs_truncate_control and use that to look up the inode items to
truncate.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:13 +0000 (17:18 -0500)]
btrfs: use a flag to control when to clear the file extent range
We only care about updating the file extent range when we are doing a
normal truncation. We skip this for tree logging currently, but we can
also skip this for eviction as well. Using a flag makes it more
explicit when we want to do this work.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:12 +0000 (17:18 -0500)]
btrfs: control extent reference updates with a control flag for truncate
We've had weird bugs in the past where we forgot to adjust the truncate
path to deal with the fact that we can be called by the tree log path.
Instead of checking if our root is a LOG_ROOT use a flag on the
btrfs_truncate_control to indicate that we don't want to do extent
reference updates during this truncate.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:11 +0000 (17:18 -0500)]
btrfs: only call inode_sub_bytes in truncate paths that care
We currently have a bunch of awkward checks to make sure we only update
the inode i_bytes if we're truncating the real inode. Instead keep
track of the number of bytes we need to sub in the
btrfs_truncate_control, and then do the appropriate adjustment in the
truncate paths that care.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:10 +0000 (17:18 -0500)]
btrfs: only update i_size in truncate paths that care
We currently will update the i_size of the inode as we truncate it down,
however we skip this if we're calling btrfs_truncate_inode_items from
the tree log code. However we also don't care about this in the case of
evict. Instead keep track of this value in the btrfs_truncate_control
and then have btrfs_truncate() and the free space cache truncate path
both do the i_size update themselves.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:09 +0000 (17:18 -0500)]
btrfs: add truncate control struct
I'm going to be adding more arguments and counters to
btrfs_truncate_inode_items, so add a control struct to handle all of the
extra arguments to make it easier to follow.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:08 +0000 (17:18 -0500)]
btrfs: remove found_extent from btrfs_truncate_inode_items
We only set this if we find a normal file extent, del_item == 1, and the
file extent points to a real extent and isn't a hole extent. We can use
del_item == 1 && extent_start != 0 to get the same information that
found_extent provides, so remove this variable and use the other
variables instead.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:07 +0000 (17:18 -0500)]
btrfs: move btrfs_kill_delayed_inode_items into evict
We have a special case in btrfs_truncate_inode_items() to call
btrfs_kill_delayed_inode_items() if min_type == 0, which is only called
during evict.
Instead move this out into evict proper, and add some comments because I
erroneously attempted to remove this code altogether without
understanding what we were doing.
Evict is updating the inode only because we only care about making sure
the i_nlink count has hit disk. If we had pending deletions we don't
want to process those via the delayed inode updates, we simply want to
drop all of them and reclaim the reserved metadata space. Then from
there the btrfs_truncate_inode_items() will do the work to remove all of
the items as appropriate.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:06 +0000 (17:18 -0500)]
btrfs: remove free space cache inode check in btrfs_truncate_inode_items
We no longer have inode cache feature, so this check is extraneous as
the only inode cache is in the tree_root, which is not marked as
SHAREABLE.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:05 +0000 (17:18 -0500)]
btrfs: move extent locking outside of btrfs_truncate_inode_items
Currently we are locking the extent and dropping the extent cache for
any inodes we truncate, unless they're in the tree log. We call this
helper from:
- truncate
- evict
- tree log
- free space cache truncation
For evict we've already dropped all of the extent cache for this inode
once we've gotten here, and we're the only one accessing this inode, so
this step is unnecessary.
For the tree log code we already skip this part.
Pull this work into the truncate path and the free space cache
truncation path.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:04 +0000 (17:18 -0500)]
btrfs: move btrfs_truncate_inode_items to inode-item.c
This is an inode item related manipulation with a few vfs related
adjustments. I'm going to remove the vfs related code from this helper
and simplify it a lot, but I want those changes to be easily seen via
git blame, so move this function now and then the simplification work
can be done.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 3 Dec 2021 22:18:03 +0000 (17:18 -0500)]
btrfs: add an inode-item.h
We have a few helpers in inode-item.c, and I'm going to make a few
changes to how we do truncate in the future, so break out these
definitions into their own header file to trim down ctree.h some and
make it easier to do the work on truncate in the future.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:40 +0000 (10:30 +0000)]
btrfs: remove stale comment about locking at btrfs_search_slot()
The comment refers to the old extent buffer locking code, where we used to
have custom locks that had blocking and spinning behaviour modes. That is
not the case anymore, since we have transitioned to rw semaphores, so the
comment does not offer any value anymore. Remove it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:39 +0000 (10:30 +0000)]
btrfs: remove BUG_ON() after splitting leaf
After calling split_leaf() we BUG_ON() if the returned value is greater
than zero. However split_leaf() only returns 0, in case of success, or a
negative value in case of an error.
The reason for the BUG_ON() is that if we ever get a positive return
value from split_leaf(), we can not simply propagate it to the callers
of btrfs_search_slot(), as that would be interpreted as "key not found"
and not as an error. That means it could result in callers ending up
causing some potential silent corruption.
So change the BUG_ON() to an ASSERT(), and in case assertions are
disabled, produce a warning and set the return value to an error, to make
it not possible to get into a silent corruption and having the error not
noticed.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:38 +0000 (10:30 +0000)]
btrfs: move leaf search logic out of btrfs_search_slot()
There's quite a significant amount of code for doing the key search for a
leaf at btrfs_search_slot(), with a couple labels and gotos in it, plus
btrfs_search_slot() is already big enough.
So move the logic that does the key search on a leaf into a new helper
function. This makes it better organized, removing the need for the labels
and the gotos, as well as reducing the indentation level and the size of
btrfs_search_slot().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:37 +0000 (10:30 +0000)]
btrfs: remove useless condition check before splitting leaf
When inserting a key, we check if the write_lock_level is less than 1,
and if so we set it to 1, release the path and retry the tree traversal.
However that is unnecessary, because when ins_len is greater than 0, we
know that write_lock_level can never be less than 1.
The logic to retry is also buggy, because in case ins_len was decremented,
due to an exact key match and the search is not meant for item extension
(path->search_for_extension is 0), we retry without incrementing ins_len,
which would make the next retry decrement it again by the same amount.
So remove the check for write_lock_level being less than 1 and add an
assertion to assert it's always >= 1.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:36 +0000 (10:30 +0000)]
btrfs: try to unlock parent nodes earlier when inserting a key
When inserting a new key, we release the write lock on the leaf's parent
only after doing the binary search on the leaf. This is because if the
key ends up at slot 0, we will have to update the key at slot 0 of the
parent node. The same reasoning applies to any other upper level nodes
when their slot is 0. We also need to keep the parent locked in case the
leaf does not have enough free space to insert the new key/item, because
in that case we will split the leaf and we will need to add a new key to
the parent due to a new leaf resulting from the split operation.
However if the leaf has enough space for the new key and the key does not
end up at slot 0 of the leaf we could release our write lock on the parent
before doing the binary search on the leaf to figure out the destination
slot. That leads to reducing the amount of time other tasks are blocked
waiting to lock the parent, therefore increasing parallelism when there
are other tasks that are trying to access other leaves accessible through
the same parent. This also applies to other upper nodes besides the
immediate parent, when their slot is 0, since we keep locks on them until
we figure out if the leaf slot is slot 0 or not.
In fact, having the key ending at up slot 0 when is rare. Typically it
only happens when the key is less than or equals to the smallest, the
"left most", key of the entire btree, during a split attempt when we try
to push to the right sibling leaf or when the caller just wants to update
the item of an existing key. It's also very common that a leaf has enough
space to insert a new key, since after a split we move about half of the
keys from one into the new leaf.
So unlock the parent, and any other upper level nodes, when during a key
insertion we notice the key is greater then the first key in the leaf and
the leaf has enough free space. After unlocking the upper level nodes, do
the binary search using a low boundary of slot 1 and not slot 0, to figure
out the slot where the key will be inserted (or where the key already is
in case it exists and the caller wants to modify its item data).
This extra comparison, with the first key, is cheap and the key is very
likely already in a cache line because it immediately follows the header
of the extent buffer and we have recently read the level field of the
header (which in fact is the last field of the header).
The following fs_mark test was run on a non-debug kernel (debian's default
kernel config), with a 12 cores intel CPU, and using a NVMe device:
$ cat run-fsmark.sh
#!/bin/bash
DEV=/dev/nvme0n1
MNT=/mnt/nvme0n1
MOUNT_OPTIONS="-o ssd"
MKFS_OPTIONS="-O no-holes -R free-space-tree"
FILES=100000
THREADS=$(nproc --all)
FILE_SIZE=0
echo "performance" | \
tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
mkfs.btrfs -f $MKFS_OPTIONS $DEV
mount $MOUNT_OPTIONS $DEV $MNT
OPTS="-S 0 -L 10 -n $FILES -s $FILE_SIZE -t $THREADS -k"
for ((i = 1; i <= $THREADS; i++)); do
OPTS="$OPTS -d $MNT/d$i"
done
fs_mark $OPTS
umount $MNT
Before this change:
FSUse% Count Size Files/sec App Overhead
0
1200000 0 165273.6
5958381
0
2400000 0 190938.3
6284477
0
3600000 0 181429.1
6044059
0
4800000 0 173979.2
6223418
0
6000000 0 139288.0
6384560
0
7200000 0 163000.4
6520083
1
8400000 0 57799.2
5388544
1
9600000 0 66461.6
5552969
2
10800000 0 49593.5
5163675
2
12000000 0 57672.1
4889398
After this change:
FSUse% Count Size Files/sec App Overhead
0
1200000 0 167987.3 (+1.6%)
6272730
0
2400000 0 198563.9 (+4.0%)
6048847
0
3600000 0 197436.6 (+8.8%)
6163637
0
4800000 0 202880.7 (+16.6%)
6371771
1
6000000 0 167275.9 (+20.1%)
6556733
1
7200000 0 204051.2 (+25.2%)
6817091
1
8400000 0 69622.8 (+20.5%)
5525675
1
9600000 0 69384.5 (+4.4%)
5700723
1
10800000 0 61454.1 (+23.9%)
5363754
3
12000000 0 61908.7 (+7.3%)
5370196
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 2 Dec 2021 10:30:35 +0000 (10:30 +0000)]
btrfs: allow generic_bin_search() to take low boundary as an argument
Right now generic_bin_search() always uses a low boundary slot of 0, but
in the next patch we'll want to often skip slot 0 when searching for a
key. So make generic_bin_search() have the low boundary slot specified
as an argument, and move the check for the extent buffer level from
btrfs_bin_search() to generic_bin_search() to avoid adding another
wrapper around generic_bin_search().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 24 Nov 2021 19:14:24 +0000 (14:14 -0500)]
btrfs: check the root node for uptodate before returning it
Now that we clear the extent buffer uptodate if we fail to write it out
we need to check to see if our root node is uptodate before we search
down it. Otherwise we could return stale data (or potentially corrupt
data that was caught by the write verification step) and think that the
path is OK to search down.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Thu, 25 Nov 2021 09:14:43 +0000 (11:14 +0200)]
btrfs: allow device add if balance is paused
Currently paused balance precludes adding a device since they are both
considered exclusive ops and we can have at most one running at a time.
This is problematic in case a filesystem encounters an ENOSPC situation
while balance is running, in this case the only thing the user can do
is mount the fs with "skip_balance" which pauses balance and delete some
data to free up space for balance. However, it should be possible to add
a new device when balance is paused.
Fix this by allowing device add to proceed when balance is paused.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Thu, 25 Nov 2021 09:14:42 +0000 (11:14 +0200)]
btrfs: make device add compatible with paused balance in btrfs_exclop_start_try_lock
This is needed to enable device add to work in cases when a file system
has been mounted with 'skip_balance' mount option.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Thu, 25 Nov 2021 09:14:41 +0000 (11:14 +0200)]
btrfs: introduce exclusive operation BALANCE_PAUSED state
Current set of exclusive operation states is not sufficient to handle
all practical use cases. In particular there is a need to be able to add
a device to a filesystem that have paused balance. Currently there is no
way to distinguish between a running and a paused balance. Fix this by
introducing BTRFS_EXCLOP_BALANCE_PAUSED which is going to be set in 2
occasions:
1. When a filesystem is mounted with skip_balance and there is an
unfinished balance it will now be into BALANCE_PAUSED instead of
simply BALANCE state.
2. When a running balance is paused.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 22 Nov 2021 12:03:38 +0000 (12:03 +0000)]
btrfs: make send work with concurrent block group relocation
We don't allow send and balance/relocation to run in parallel in order
to prevent send failing or silently producing some bad stream. This is
because while send is using an extent (specially metadata) or about to
read a metadata extent and expecting it belongs to a specific parent
node, relocation can run, the transaction used for the relocation is
committed and the extent gets reallocated while send is still using the
extent, so it ends up with a different content than expected. This can
result in just failing to read a metadata extent due to failure of the
validation checks (parent transid, level, etc), failure to find a
backreference for a data extent, and other unexpected failures. Besides
reallocation, there's also a similar problem of an extent getting
discarded when it's unpinned after the transaction used for block group
relocation is committed.
The restriction between balance and send was added in commit
9e967495e0e0
("Btrfs: prevent send failures and crashes due to concurrent relocation"),
kernel 5.3, while the more general restriction between send and relocation
was added in commit
1cea5cf0e664 ("btrfs: ensure relocation never runs
while we have send operations running"), kernel 5.14.
Both send and relocation can be very long running operations. Relocation
because it has to do a lot of IO and expensive backreference lookups in
case there are many snapshots, and send due to read IO when operating on
very large trees. This makes it inconvenient for users and tools to deal
with scheduling both operations.
For zoned filesystem we also have automatic block group relocation, so
send can fail with -EAGAIN when users least expect it or send can end up
delaying the block group relocation for too long. In the future we might
also get the automatic block group relocation for non zoned filesystems.
This change makes it possible for send and relocation to run in parallel.
This is achieved the following way:
1) For all tree searches, send acquires a read lock on the commit root
semaphore;
2) After each tree search, and before releasing the commit root semaphore,
the leaf is cloned and placed in the search path (struct btrfs_path);
3) After releasing the commit root semaphore, the changed_cb() callback
is invoked, which operates on the leaf and writes commands to the pipe
(or file in case send/receive is not used with a pipe). It's important
here to not hold a lock on the commit root semaphore, because if we did
we could deadlock when sending and receiving to the same filesystem
using a pipe - the send task blocks on the pipe because it's full, the
receive task, which is the only consumer of the pipe, triggers a
transaction commit when attempting to create a subvolume or reserve
space for a write operation for example, but the transaction commit
blocks trying to write lock the commit root semaphore, resulting in a
deadlock;
4) Before moving to the next key, or advancing to the next change in case
of an incremental send, check if a transaction used for relocation was
committed (or is about to finish its commit). If so, release the search
path(s) and restart the search, to where we were before, so that we
don't operate on stale extent buffers. The search restarts are always
possible because both the send and parent roots are RO, and no one can
add, remove of update keys (change their offset) in RO trees - the
only exception is deduplication, but that is still not allowed to run
in parallel with send;
5) Periodically check if there is contention on the commit root semaphore,
which means there is a transaction commit trying to write lock it, and
release the semaphore and reschedule if there is contention, so as to
avoid causing any significant delays to transaction commits.
This leaves some room for optimizations for send to have less path
releases and re searching the trees when there's relocation running, but
for now it's kept simple as it performs quite well (on very large trees
with resulting send streams in the order of a few hundred gigabytes).
Test case btrfs/187, from fstests, stresses relocation, send and
deduplication attempting to run in parallel, but without verifying if send
succeeds and if it produces correct streams. A new test case will be added
that exercises relocation happening in parallel with send and then checks
that send succeeds and the resulting streams are correct.
A final note is that for now this still leaves the mutual exclusion
between send operations and deduplication on files belonging to a root
used by send operations. A solution for that will be slightly more complex
but it will eventually be built on top of this change.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 23 Nov 2021 12:44:22 +0000 (14:44 +0200)]
btrfs: change name and type of private member of btrfs_free_space_ctl
btrfs_free_space_ctl::private is either unset or it always points to
struct btrfs_block_group when it is set. So there's no point in keeping
the unhelpful 'private' name and keeping it an untyped pointer. Change
both the type and name to be self-describing. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 23 Nov 2021 12:44:21 +0000 (14:44 +0200)]
btrfs: make __btrfs_add_free_space take just block group reference
There is no point in the function taking an fs_info and a
btrfs_free_space because the ctl passed always belongs to the block
group. Furthermore fs_info can be referenced from the block group. No
functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 23 Nov 2021 12:44:20 +0000 (14:44 +0200)]
btrfs: consolidate unlink_free_space/__unlink_free_space functions
The only difference between the two is whether btrfs_free_space::bytes
is adjusted. Instead of having 2 separate functions control this
behavior via an additional parameter and make them one function instead.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 23 Nov 2021 12:44:19 +0000 (14:44 +0200)]
btrfs: consolidate bitmap_clear_bits/__bitmap_clear_bits
The only difference is the former adjusts btrfs_free_space::bytes
member. Consolidate the two function into 1 and add a bool parameter
which controls whether the adjustment is made or not. No functional
changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:51 +0000 (16:45 -0400)]
btrfs: track the csum, extent, and free space trees in a rb tree
In the future we are going to have multiple copies of these trees. To
facilitate this we need a way to lookup the different roots we are
looking for. Handle this by adding a global root rb tree that is
indexed on the root->root_key. Then instead of loading the roots at
mount time with individually targeted keys, simply search the tree_root
for anything with the specific objectid we want. This will make it
straightforward to support both old style and new style file systems.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:50 +0000 (16:45 -0400)]
btrfs: remove useless WARN_ON in record_root_in_trans
We don't set SHAREABLE on the extent root, we don't need to have this
safety check here.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:49 +0000 (16:45 -0400)]
btrfs: stop accessing ->free_space_root directly
We're going to have multiple free space roots in the future, so adjust
all the users of the free space root to use a helper to access the root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:48 +0000 (16:45 -0400)]
btrfs: stop accessing ->csum_root directly
We are going to have multiple csum roots in the future, so convert all
users of ->csum_root to btrfs_csum_root() and rename ->csum_root to
->_csum_root so we can easily find remaining users in the future.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:47 +0000 (16:45 -0400)]
btrfs: set BTRFS_FS_STATE_NO_CSUMS if we fail to load the csum root
We have a few places where we skip doing csums if we mounted with one of
the rescue options that ignores bad csum roots. In the future when
there are multiple csum roots it'll be costly to check and see if there
are any missing csum roots, so simply add a flag to indicate the fs
should skip loading csums in case of errors.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:46 +0000 (16:45 -0400)]
btrfs: fix csum assert to check objectid of the root
In the future we may have multiple csum roots, so simply check the
objectid is for a csum root instead of checking against ->csum_root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:45 +0000 (16:45 -0400)]
btrfs: stop accessing ->extent_root directly
When we start having multiple extent roots we'll need to use a helper to
get to the correct extent_root. Rename fs_info->extent_root to
_extent_root and convert all of the users of the extent root to using
the btrfs_extent_root() helper. This will allow us to easily clean up
the remaining direct accesses in the future.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:44 +0000 (16:45 -0400)]
btrfs: init root block_rsv at init root time
In the future we're going to have multiple csum and extent root trees,
so init the roots block_rsv at setup_root time based on their root key
objectid.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:43 +0000 (16:45 -0400)]
btrfs: don't use the extent_root in flush_space
We only need the root to start a transaction, and since it's a global
root we can pick anything, change to the tree_root as we'll have a lot
of extent roots in the future.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:42 +0000 (16:45 -0400)]
btrfs: don't use extent_root in iterate_extent_inodes
We are going to have many extent_roots soon, and we don't need a root
here necessarily as we're not modifying anything, we're just getting the
trans handle so we can have an accurate view of references, so use the
tree_root here.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:41 +0000 (16:45 -0400)]
btrfs: don't use the extent root in btrfs_chunk_alloc_add_chunk_item
We're just using the extent_root to set the chunk owner to
root_key->objectid, which is BTRFS_EXTENT_TREE_OBJECTID, so use that
directly instead of using the root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:40 +0000 (16:45 -0400)]
btrfs: remove unnecessary extent root check in btrfs_defrag_leaves
We only defrag leaves on roots that have SHAREABLE set, so we don't need
to check if we're the extent root as it doesn't have SHAREABLE set.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:39 +0000 (16:45 -0400)]
btrfs: do not special case the extent root for switch commit roots
This is a leftover from when we used to independently swap the extent
root's commit root and the fs tree commit roots. At the time I simply
changed the helper to a list_add. There's actually no reason to not add
the extent root to the switch commit root at this point, we don't care
about the order we do the switching since it's all done under the
commit_root_sem.
If we re-mark the extent root dirty after adding it to the
switch_commits list we'll see that BTRFS_ROOT_DIRTY isn't set and then
list_move it back onto the dirty list, and then we'll redo the tree
update and everything will be ok.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:38 +0000 (16:45 -0400)]
btrfs: use chunk_root in find_free_extent_update_loop
We're only using this to start the transaction with to possibly allocate
a chunk. It doesn't really matter which root to use, but with extent
tree v2 we'll need a bytenr to look up a extent root which makes the
usage of the extent_root awkward here. Simply change it to the
chunk_root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:37 +0000 (16:45 -0400)]
btrfs: make remove_extent_backref pass the root
With extent tree v2 we'll have a different extent root based on where
the bytenr is located, so adjust the remove_extent_backref() helper and
it's helpers to pass the extent_root around.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:36 +0000 (16:45 -0400)]
btrfs: add a btrfs_block_group_root() helper
With extent tree v2 we will have a separate root to hold the block group
items. Add a btrfs_block_group_root() that will return the appropriate
root given the flags of the fs, and convert all functions that need to
modify block group items to use the helper.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:35 +0000 (16:45 -0400)]
btrfs: remove BUG_ON(!eie) in find_parent_nodes
If we're looking for leafs that point to a data extent we want to record
the extent items that point at our bytenr. At this point we have the
reference and we know for a fact that this leaf should have a reference
to our bytenr. However if there's some sort of corruption we may not
find any references to our leaf, and thus could end up with eie == NULL.
Replace this BUG_ON() with an ASSERT() and then return -EUCLEAN for the
mortals.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:34 +0000 (16:45 -0400)]
btrfs: remove BUG_ON() in find_parent_nodes()
We search for an extent entry with .offset = -1, which shouldn't be a
thing, but corruption happens. Add an ASSERT() for the developers,
return -EUCLEAN for mortals.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:33 +0000 (16:45 -0400)]
btrfs: remove SANITY_TESTS check form find_parent_nodes
We define __TRANS_DUMMY always, so this extra ifdef stuff is not needed.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:32 +0000 (16:45 -0400)]
btrfs: move comment in find_parent_nodes()
This comment was much closer to the related code when it was originally
added, but has slowly migrated north far from its ancestral lands. Move
it back down with its people.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:31 +0000 (16:45 -0400)]
btrfs: pass the root to add_keyed_refs
We pass in the path, but use btrfs_next_item() using the root we
searched with. Pass the root down to add_keyed_refs() instead of the
fs_info so we can continue to use the same root we searched with.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:30 +0000 (16:45 -0400)]
btrfs: remove trans_handle->root
Nobody is using this anymore, remove it.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:29 +0000 (16:45 -0400)]
btrfs: pass fs_info to trace_btrfs_transaction_commit
The root on the trans->root can be anything, and generally we're
committing from the transaction kthread so it's usually the tree_root.
Change this to just take an fs_info, and to maintain compatibility
simply put the ROOT_TREE_OBJECTID as the root objectid for the
tracepoint. This will allow use to remove trans->root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:28 +0000 (16:45 -0400)]
btrfs: rework async transaction committing
Currently we do this awful thing where we get another ref on a trans
handle, async off that handle and commit the transaction from that work.
Because we do this we have to mess with current->journal_info and the
freeze counting stuff.
We already have an async thing to kick for the transaction commit, the
transaction kthread. Replace this work struct with a flag on the
fs_info to tell the kthread to go ahead and commit even if it's before
our timeout. Then we can drastically simplify the async transaction
commit path.
Note: this can be simplified and functionality based on the pending
operation COMMIT.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add note ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 5 Nov 2021 20:45:27 +0000 (16:45 -0400)]
btrfs: remove unused BTRFS_FS_BARRIER flag
This is no longer used, the -o nobarrier is handled by
BTRFS_MOUNT_NOBARRIER. Remove the flag.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Tue, 23 Nov 2021 07:23:42 +0000 (09:23 +0200)]
btrfs: eliminate if in main loop in tree_search_offset
Reshuffle the code inside the first loop of tree_search_offset so that
one if() is eliminated and the becomes more linear.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Fri, 19 Nov 2021 06:19:33 +0000 (14:19 +0800)]
btrfs: don't check stripe length if the profile is not stripe based
[BUG]
When debugging calc_bio_boundaries(), I found that even for RAID1
metadata, we're following stripe length to calculate stripe boundary.
# mkfs.btrfs -m raid1 -d raid1 /dev/test/scratch[12]
# mount /dev/test/scratch /mnt/btrfs
# xfs_io -f -c "pwrite 0 64K" /mnt/btrfs/file
# umount
Above very basic operations will make calc_bio_boundaries() to report
the following result:
submit_extent_page: r/i=1/1 file_offset=
22036480 len_to_stripe_boundary=49152
submit_extent_page: r/i=1/1 file_offset=
30474240 len_to_stripe_boundary=65536
...
submit_extent_page: r/i=1/1 file_offset=
30523392 len_to_stripe_boundary=16384
submit_extent_page: r/i=1/1 file_offset=
30457856 len_to_stripe_boundary=16384
submit_extent_page: r/i=5/257 file_offset=0 len_to_stripe_boundary=65536
submit_extent_page: r/i=5/257 file_offset=65536 len_to_stripe_boundary=65536
submit_extent_page: r/i=1/1 file_offset=
30490624 len_to_stripe_boundary=49152
submit_extent_page: r/i=1/1 file_offset=
30507008 len_to_stripe_boundary=32768
Where "r/i" is the rootid and inode, 1/1 means they metadata.
The remaining names match the member used in kernel.
Even all data/metadata are using RAID1, we're still following stripe
length.
[CAUSE]
This behavior is caused by a wrong condition in btrfs_get_io_geometry():
if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
/* Fill using stripe_len */
len = min_t(u64, em->len - offset, max_len);
} else {
len = em->len - offset;
}
This means, only for SINGLE we will not follow stripe_len.
However for profiles like RAID1*, DUP, they don't need to bother
stripe_len.
This can lead to unnecessary bio split for RAID1*/DUP profiles, and can
even be a blockage for future zoned RAID support.
[FIX]
Introduce one single-use macro, BTRFS_BLOCK_GROUP_STRIPE_MASK, and
change the condition to only calculate the length using stripe length
for stripe based profiles.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Mon, 22 Nov 2021 15:16:46 +0000 (17:16 +0200)]
btrfs: get next entry in tree_search_offset before doing checks
This is a small optimisation since the currently 'entry' is already
checked in the if () {} else if {} construct above the loop. In essence
the first iteration of the final while loop is redundant. To eliminate
this extra check simply get the next entry at the beginning of the loop.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Thu, 18 Nov 2021 21:33:16 +0000 (16:33 -0500)]
btrfs: add self test for bytes_index free space cache
I noticed a few corner cases when looking at my bytes_index patch for
obvious bugs, so add a bunch of tests to validate proper behavior of the
bytes_index tree. A couple of basic tests to make sure it puts things
in the correct order, and then more complicated tests to make sure it
re-arranges bitmap entries properly and does the right thing when we try
to make allocations.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>