Commit 38d715f494 ("btrfs: use btrfs_start_delalloc_roots in
shrink_delalloc") cleaned up how we do delalloc shrinking by utilizing
some infrastructure we have in place to flush inodes that we use for
device replace and snapshot. However this introduced a pretty serious
performance regression. To reproduce the user untarred the source
tarball of Firefox (360MiB xz compressed/1.5GiB uncompressed), and would
see it take anywhere from 5 to 20 times as long to untar in 5.10
compared to 5.9. This was observed on fast devices (SSD and better) and
not on HDD.
The root cause is because before we would generally use the normal
writeback path to reclaim delalloc space, and for this we would provide
it with the number of pages we wanted to flush. The referenced commit
changed this to flush that many inodes, which drastically increased the
amount of space we were flushing in certain cases, which severely
affected performance.
We cannot revert this patch unfortunately because of 3d45f221ce
("btrfs: fix deadlock when cloning inline extent and low on free
metadata space") which requires the ability to skip flushing inodes that
are being cloned in certain scenarios, which means we need to keep using
our flushing infrastructure or risk re-introducing the deadlock.
Instead to fix this problem we can go back to providing
btrfs_start_delalloc_roots with a number of pages to flush, and then set
up a writeback_control and utilize sync_inode() to handle the flushing
for us. This gives us the same behavior we had prior to the fix, while
still allowing us to avoid the deadlock that was fixed by Filipe. I
redid the users original test and got the following results on one of
our test machines (256GiB of ram, 56 cores, 2TiB Intel NVMe drive)
5.9 0m54.258s
5.10 1m26.212s
5.10+patch 0m38.800s
5.10+patch is significantly faster than plain 5.9 because of my patch
series "Change data reservations to use the ticketing infra" which
contained the patch that introduced the regression, but generally
improved the overall ENOSPC flushing mechanisms.
Additional testing on consumer-grade SSD (8GiB ram, 8 CPU) confirm
the results:
5.10.5 4m00s
5.10.5+patch 1m08s
5.11-rc2 5m14s
5.11-rc2+patch 1m30s
Reported-by: René Rebe <rene@exactcode.de>
Fixes: 38d715f494 ("btrfs: use btrfs_start_delalloc_roots in shrink_delalloc")
CC: stable@vger.kernel.org # 5.10
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: David Sterba <dsterba@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add my test results ]
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There are several bug reports about recent kernel unable to relocate
certain data block groups.
Sometimes the error just goes away, but there is one reporter who can
reproduce it reliably.
The dmesg would look like:
[438.260483] BTRFS info (device dm-10): balance: start -dvrange=34625344765952..34625344765953
[438.269018] BTRFS info (device dm-10): relocating block group 34625344765952 flags data|raid1
[450.439609] BTRFS info (device dm-10): found 167 extents, stage: move data extents
[463.501781] BTRFS info (device dm-10): balance: ended with status: -2
[CAUSE]
The ENOENT error is returned from the following call chain:
add_data_references()
|- delete_v1_space_cache();
|- if (!found)
return -ENOENT;
The variable @found is set to true if we find a data extent whose
disk bytenr matches parameter @data_bytes.
With extra debugging, the offending tree block looks like this:
leaf bytenr = 42676709441536, data_bytenr = 34626327621632
ctime 1567904822.739884119 (2019-09-08 03:07:02)
mtime 0.0 (1970-01-01 01:00:00)
otime 0.0 (1970-01-01 01:00:00)
item 27 key (51933 EXTENT_DATA 0) itemoff 9854 itemsize 53
generation 1517381 type 2 (prealloc)
prealloc data disk byte 34626327621632 nr 262144 <<<
prealloc data offset 0 nr 262144
item 28 key (52262 ROOT_ITEM 0) itemoff 9415 itemsize 439
generation 2618893 root_dirid 256 bytenr 42677048360960 level 3 refs 1
lastsnap 2618893 byte_limit 0 bytes_used 5557338112 flags 0x0(none)
uuid d0d4361f-d231-6d40-8901-fe506e4b2b53
Although item 27 has disk bytenr 34626327621632, which matches the
data_bytenr, its type is prealloc, not reg.
This makes the existing code skip that item, and return ENOENT.
[FIX]
The code is modified in commit 19b546d7a1 ("btrfs: relocation: Use
btrfs_find_all_leafs to locate data extent parent tree leaves"), before
that commit, we use something like
"if (type == BTRFS_FILE_EXTENT_INLINE) continue;"
But in that offending commit, we use (type == BTRFS_FILE_EXTENT_REG),
ignoring BTRFS_FILE_EXTENT_PREALLOC.
Fix it by also checking BTRFS_FILE_EXTENT_PREALLOC.
Reported-by: Stéphane Lesimple <stephane_btrfs2@lesimple.fr>
Link: https://lore.kernel.org/linux-btrfs/505cabfa88575ed6dbe7cb922d8914fb@lesimple.fr
Fixes: 19b546d7a1 ("btrfs: relocation: Use btrfs_find_all_leafs to locate data extent parent tree leaves")
CC: stable@vger.kernel.org # 5.6+
Tested-By: Stéphane Lesimple <stephane_btrfs2@lesimple.fr>
Reviewed-by: Su Yue <l@damenly.su>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Some extent io trees are initialized with NULL private member (e.g.
btrfs_device::alloc_state and btrfs_fs_info::excluded_extents).
Dereference of a NULL tree->private as inode pointer will cause panic.
Pass tree->fs_info as it's known to be valid in all cases.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208929
Fixes: 05912a3c04 ("btrfs: drop extent_io_ops::tree_fs_info callback")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're supposed to print the root_key.offset in btrfs_root_name in the
case of a reloc root, not the objectid. Fix this helper to take the key
so we have access to the offset when we need it.
Fixes: 457f1864b5 ("btrfs: pretty print leaked root name")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@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>
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Merge tag 'for-5.11-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more fixes that arrived before the end of the year:
- a bunch of fixes related to transaction handle lifetime wrt various
operations (umount, remount, qgroup scan, orphan cleanup)
- async discard scheduling fixes
- fix item size calculation when item keys collide for extend refs
(hardlinks)
- fix qgroup flushing from running transaction
- fix send, wrong file path when there is an inode with a pending
rmdir
- fix deadlock when cloning inline extent and low on free metadata
space"
* tag 'for-5.11-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: run delayed iputs when remounting RO to avoid leaking them
btrfs: add assertion for empty list of transactions at late stage of umount
btrfs: fix race between RO remount and the cleaner task
btrfs: fix transaction leak and crash after cleaning up orphans on RO mount
btrfs: fix transaction leak and crash after RO remount caused by qgroup rescan
btrfs: merge critical sections of discard lock in workfn
btrfs: fix racy access to discard_ctl data
btrfs: fix async discard stall
btrfs: tests: initialize test inodes location
btrfs: send: fix wrong file path when there is an inode with a pending rmdir
btrfs: qgroup: don't try to wait flushing if we're already holding a transaction
btrfs: correctly calculate item size used when item key collision happens
btrfs: fix deadlock when cloning inline extent and low on free metadata space
When remounting RO, after setting the superblock with the RO flag, the
cleaner task will start sleeping and do nothing, since the call to
btrfs_need_cleaner_sleep() keeps returning 'true'. However, when the
cleaner task goes to sleep, the list of delayed iputs may not be empty.
As long as we are in RO mode, the cleaner task will keep sleeping and
never run the delayed iputs. This means that if a filesystem unmount
is started, we get into close_ctree() with a non-empty list of delayed
iputs, and because the filesystem is in RO mode and is not in an error
state (or a transaction aborted), btrfs_error_commit_super() and
btrfs_commit_super(), which run the delayed iputs, are never called,
and later we fail the assertion that checks if the delayed iputs list
is empty:
assertion failed: list_empty(&fs_info->delayed_iputs), in fs/btrfs/disk-io.c:4049
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3153!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 1 PID: 3780621 Comm: umount Tainted: G L 5.6.0-rc2-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
RIP: 0010:assertfail.constprop.0+0x18/0x26 [btrfs]
Code: 8b 7b 58 48 85 ff 74 (...)
RSP: 0018:ffffb748c89bbdf8 EFLAGS: 00010246
RAX: 0000000000000051 RBX: ffff9608f2584000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff91998988 RDI: 00000000ffffffff
RBP: ffff9608f25870d8 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffc0cbc500
R13: ffffffff92411750 R14: 0000000000000000 R15: ffff9608f2aab250
FS: 00007fcbfaa66c80(0000) GS:ffff960936c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc2c2dd38 CR3: 0000000235e54002 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
close_ctree+0x1a2/0x2e6 [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x93/0xc0
exit_to_usermode_loop+0xf9/0x100
do_syscall_64+0x20d/0x260
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fcbfaca6307
Code: eb 0b 00 f7 d8 64 89 (...)
RSP: 002b:00007fffc2c2ed68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000558203b559b0 RCX: 00007fcbfaca6307
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000558203b55bc0
RBP: 0000000000000000 R08: 0000000000000001 R09: 00007fffc2c2dad0
R10: 0000558203b55bf0 R11: 0000000000000246 R12: 0000558203b55bc0
R13: 00007fcbfadcc204 R14: 0000558203b55aa8 R15: 0000000000000000
Modules linked in: btrfs dm_flakey dm_log_writes (...)
---[ end trace d44d303790049ef6 ]---
So fix this by making the remount RO path run any remaining delayed iputs
after waiting for the cleaner to become inactive.
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>
Add an assertion to close_ctree(), after destroying all the work queues,
to verify we do not have any transaction still open or committing at that
at that point. If we have any, it means something is seriously wrong and
that can cause memory leaks and use-after-free problems. This is motivated
by the previous patches that fixed bugs where we ended up leaking an open
transaction after unmounting the filesystem.
Tested-by: Fabian Vogt <fvogt@suse.com>
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>
When we are remounting a filesystem in RO mode we can race with the cleaner
task and result in leaking a transaction if the filesystem is unmounted
shortly after, before the transaction kthread had a chance to commit that
transaction. That also results in a crash during unmount, due to a
use-after-free, if hardware acceleration is not available for crc32c.
The following sequence of steps explains how the race happens.
1) The filesystem is mounted in RW mode and the cleaner task is running.
This means that currently BTRFS_FS_CLEANER_RUNNING is set at
fs_info->flags;
2) The cleaner task is currently running delayed iputs for example;
3) A filesystem RO remount operation starts;
4) The RO remount task calls btrfs_commit_super(), which commits any
currently open transaction, and it finishes;
5) At this point the cleaner task is still running and it creates a new
transaction by doing one of the following things:
* When running the delayed iput() for an inode with a 0 link count,
in which case at btrfs_evict_inode() we start a transaction through
the call to evict_refill_and_join(), use it and then release its
handle through btrfs_end_transaction();
* When deleting a dead root through btrfs_clean_one_deleted_snapshot(),
a transaction is started at btrfs_drop_snapshot() and then its handle
is released through a call to btrfs_end_transaction_throttle();
* When the remount task was still running, and before the remount task
called btrfs_delete_unused_bgs(), the cleaner task also called
btrfs_delete_unused_bgs() and it picked and removed one block group
from the list of unused block groups. Before the cleaner task started
a transaction, through btrfs_start_trans_remove_block_group() at
btrfs_delete_unused_bgs(), the remount task had already called
btrfs_commit_super();
6) So at this point the filesystem is in RO mode and we have an open
transaction that was started by the cleaner task;
7) Shortly after a filesystem unmount operation starts. At close_ctree()
we stop the transaction kthread before it had a chance to commit the
transaction, since less than 30 seconds (the default commit interval)
have elapsed since the last transaction was committed;
8) We end up calling iput() against the btree inode at close_ctree() while
there is an open transaction, and since that transaction was used to
update btrees by the cleaner, we have dirty pages in the btree inode
due to COW operations on metadata extents, and therefore writeback is
triggered for the btree inode.
So btree_write_cache_pages() is invoked to flush those dirty pages
during the final iput() on the btree inode. This results in creating a
bio and submitting it, which makes us end up at
btrfs_submit_metadata_bio();
9) At btrfs_submit_metadata_bio() we end up at the if-then-else branch
that calls btrfs_wq_submit_bio(), because check_async_write() returned
a value of 1. This value of 1 is because we did not have hardware
acceleration available for crc32c, so BTRFS_FS_CSUM_IMPL_FAST was not
set in fs_info->flags;
10) Then at btrfs_wq_submit_bio() we call btrfs_queue_work() against the
workqueue at fs_info->workers, which was already freed before by the
call to btrfs_stop_all_workers() at close_ctree(). This results in an
invalid memory access due to a use-after-free, leading to a crash.
When this happens, before the crash there are several warnings triggered,
since we have reserved metadata space in a block group, the delayed refs
reservation, etc:
------------[ cut here ]------------
WARNING: CPU: 4 PID: 1729896 at fs/btrfs/block-group.c:125 btrfs_put_block_group+0x63/0xa0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 4 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_put_block_group+0x63/0xa0 [btrfs]
Code: f0 01 00 00 48 39 c2 75 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: ffff947ed73e4000 RCX: ffff947ebc8b29c8
RDX: 0000000000000001 RSI: ffffffffc0b150a0 RDI: ffff947ebc8b2800
RBP: ffff947ebc8b2800 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e4160 R14: ffff947ebc8b2988 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37e2893320 CR3: 0000000138f68001 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x17f/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 48 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c6 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-rsv.c:459 btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 2 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Code: 48 83 bb b0 03 00 00 00 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 000000000033c000 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffc0b0d8c1 RDI: 00000000ffffffff
RBP: ffff947ebc8b7000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481aca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561a79f76e20 CR3: 0000000138f68006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x24c/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c7 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-group.c:3377 btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 5 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Code: ad de 49 be 22 01 00 (...)
RSP: 0018:ffffb270826bbde8 EFLAGS: 00010206
RAX: ffff947ebeae1d08 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff947e9d823ae8 RDI: 0000000000000246
RBP: ffff947ebeae1d08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ebeae1c00
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1475d98ea8 CR3: 0000000138f68005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c8 ]---
BTRFS info (device sdc): space_info 4 has 268238848 free, is not full
BTRFS info (device sdc): space_info total=268435456, used=114688, pinned=0, reserved=16384, may_use=0, readonly=65536
BTRFS info (device sdc): global_block_rsv: size 0 reserved 0
BTRFS info (device sdc): trans_block_rsv: size 0 reserved 0
BTRFS info (device sdc): chunk_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_refs_rsv: size 524288 reserved 0
And the crash, which only happens when we do not have crc32c hardware
acceleration, produces the following trace immediately after those
warnings:
stack segment: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 2 PID: 1749129 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_queue_work+0x36/0x190 [btrfs]
Code: 54 55 53 48 89 f3 (...)
RSP: 0018:ffffb27082443ae8 EFLAGS: 00010282
RAX: 0000000000000004 RBX: ffff94810ee9ad90 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff94810ee9ad90 RDI: ffff947ed8ee75a0
RBP: a56b6b6b6b6b6b6b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000001 R12: ffff947fa9b435a8
R13: ffff94810ee9ad90 R14: 0000000000000000 R15: ffff947e93dc0000
FS: 00007f3cfe974840(0000) GS:ffff9481ac600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b42995a70 CR3: 0000000127638003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_wq_submit_bio+0xb3/0xd0 [btrfs]
btrfs_submit_metadata_bio+0x44/0xc0 [btrfs]
submit_one_bio+0x61/0x70 [btrfs]
btree_write_cache_pages+0x414/0x450 [btrfs]
? kobject_put+0x9a/0x1d0
? trace_hardirqs_on+0x1b/0xf0
? _raw_spin_unlock_irqrestore+0x3c/0x60
? free_debug_processing+0x1e1/0x2b0
do_writepages+0x43/0xe0
? lock_acquired+0x199/0x490
__writeback_single_inode+0x59/0x650
writeback_single_inode+0xaf/0x120
write_inode_now+0x94/0xd0
iput+0x187/0x2b0
close_ctree+0x2c6/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f3cfebabee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffc9c9a05f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3cfecd1264 RCX: 00007f3cfebabee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 0000562b6b478000
RBP: 0000562b6b473a30 R08: 0000000000000000 R09: 00007f3cfec6cbe0
R10: 0000562b6b479fe0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000562b6b478000 R14: 0000562b6b473b40 R15: 0000562b6b473c60
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
---[ end trace dd74718fef1ed5cc ]---
Finally when we remove the btrfs module (rmmod btrfs), there are several
warnings about objects that were allocated from our slabs but were never
freed, consequence of the transaction that was never committed and got
leaked:
=============================================================================
BUG btrfs_delayed_ref_head (Tainted: G B W ): Objects remaining in btrfs_delayed_ref_head on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x0000000094c2ae56 objects=24 used=2 fp=0x000000002bfa2521 flags=0x17fffc000010200
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? lock_release+0x20e/0x4c0
kmem_cache_destroy+0x55/0x120
btrfs_delayed_ref_exit+0x11/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x0000000050cbdd61 @offset=12104
INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1894 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs]
btrfs_free_tree_block+0x128/0x360 [btrfs]
__btrfs_cow_block+0x489/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=4292 cpu=2 pid=1729526
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x1117/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
sync_filesystem+0x74/0x90
generic_shutdown_super+0x22/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
INFO: Object 0x0000000086e9b0ff @offset=12776
INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1900 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs]
btrfs_alloc_tree_block+0x2bf/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=3141 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x1117/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
btrfs_write_dirty_block_groups+0x17d/0x3d0 [btrfs]
commit_cowonly_roots+0x248/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_ref_head: Slab cache still has objects
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
btrfs_delayed_ref_exit+0x11/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 0b (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
=============================================================================
BUG btrfs_delayed_tree_ref (Tainted: G B W ): Objects remaining in btrfs_delayed_tree_ref on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x0000000011f78dc0 objects=37 used=2 fp=0x0000000032d55d91 flags=0x17fffc000010200
CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? lock_release+0x20e/0x4c0
kmem_cache_destroy+0x55/0x120
btrfs_delayed_ref_exit+0x1d/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x000000001a340018 @offset=4408
INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1917 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs]
btrfs_free_tree_block+0x128/0x360 [btrfs]
__btrfs_cow_block+0x489/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=4167 cpu=4 pid=1729795
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x63d/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
btrfs_commit_transaction+0x60/0xc40 [btrfs]
create_subvol+0x56a/0x990 [btrfs]
btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
__btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
btrfs_ioctl_snap_create+0x58/0x80 [btrfs]
btrfs_ioctl+0x1a92/0x36f0 [btrfs]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
INFO: Object 0x000000002b46292a @offset=13648
INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1923 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs]
btrfs_alloc_tree_block+0x2bf/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=3164 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x63d/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_tree_ref: Slab cache still has objects
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
btrfs_delayed_ref_exit+0x1d/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
=============================================================================
BUG btrfs_delayed_extent_op (Tainted: G B W ): Objects remaining in btrfs_delayed_extent_op on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x00000000f145ce2f objects=22 used=1 fp=0x00000000af0f92cf flags=0x17fffc000010200
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? __mutex_unlock_slowpath+0x45/0x2a0
kmem_cache_destroy+0x55/0x120
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x000000004cf95ea8 @offset=6264
INFO: Allocated in btrfs_alloc_tree_block+0x1e0/0x360 [btrfs] age=1931 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_alloc_tree_block+0x1e0/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0xabd/0x1290 [btrfs] age=3173 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0xabd/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_extent_op: Slab cache still has objects
CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
BTRFS: state leak: start 30408704 end 30425087 state 1 in tree 1 refs 1
So fix this by making the remount path to wait for the cleaner task before
calling btrfs_commit_super(). The remount path now waits for the bit
BTRFS_FS_CLEANER_RUNNING to be cleared from fs_info->flags before calling
btrfs_commit_super() and this ensures the cleaner can not start a
transaction after that, because it sleeps when the filesystem is in RO
mode and we have already flagged the filesystem as RO before waiting for
BTRFS_FS_CLEANER_RUNNING to be cleared.
This also introduces a new flag BTRFS_FS_STATE_RO to be used for
fs_info->fs_state when the filesystem is in RO mode. This is because we
were doing the RO check using the flags of the superblock and setting the
RO mode simply by ORing into the superblock's flags - those operations are
not atomic and could result in the cleaner not seeing the update from the
remount task after it clears BTRFS_FS_CLEANER_RUNNING.
Tested-by: Fabian Vogt <fvogt@suse.com>
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>
btrfs_discard_workfn() drops discard_ctl->lock just to take it again in
a moment in btrfs_discard_schedule_work(). Avoid that and also reuse
ktime.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Because only one discard worker may be running at any given point, it
could have been safe to modify ->prev_discard, etc. without
synchronization, if not for @override flag in
btrfs_discard_schedule_work() and delayed_work_pending() returning false
while workfn is running.
That may lead to torn reads of u64 for some architectures, but that's
not a big problem as only slightly affects the discard rate.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Might happen that bg->discard_eligible_time was changed without
rescheduling, so btrfs_discard_workfn() wakes up earlier than that new
time, peek_discard_list() returns NULL, and all work halts and goes to
sleep without further rescheduling even there are block groups to
discard.
It happens pretty often, but not so visible from the userspace because
after some time it usually will be kicked off anyway by someone else
calling btrfs_discard_reschedule_work().
Fix it by continue rescheduling if block group discard lists are not
empty.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I noticed that sometimes the module failed to load because the self
tests failed like this:
BTRFS: selftest: fs/btrfs/tests/inode-tests.c:963 miscount, wanted 1, got 0
This turned out to be because sometimes the btrfs ino would be the btree
inode number, and thus we'd skip calling the set extent delalloc bit
helper, and thus not adjust ->outstanding_extents.
Fix this by making sure we initialize test inodes with a valid inode
number so that we don't get random failures during self tests.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing an incremental send, if we have a new inode that happens to
have the same number that an old directory inode had in the base snapshot
and that old directory has a pending rmdir operation, we end up computing
a wrong path for the new inode, causing the receiver to fail.
Example reproducer:
$ cat test-send-rmdir.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
mkfs.btrfs -f $DEV >/dev/null
mount $DEV $MNT
mkdir $MNT/dir
touch $MNT/dir/file1
touch $MNT/dir/file2
touch $MNT/dir/file3
# Filesystem looks like:
#
# . (ino 256)
# |----- dir/ (ino 257)
# |----- file1 (ino 258)
# |----- file2 (ino 259)
# |----- file3 (ino 260)
#
btrfs subvolume snapshot -r $MNT $MNT/snap1
btrfs send -f /tmp/snap1.send $MNT/snap1
# Now remove our directory and all its files.
rm -fr $MNT/dir
# Unmount the filesystem and mount it again. This is to ensure that
# the next inode that is created ends up with the same inode number
# that our directory "dir" had, 257, which is the first free "objectid"
# available after mounting again the filesystem.
umount $MNT
mount $DEV $MNT
# Now create a new file (it could be a directory as well).
touch $MNT/newfile
# Filesystem now looks like:
#
# . (ino 256)
# |----- newfile (ino 257)
#
btrfs subvolume snapshot -r $MNT $MNT/snap2
btrfs send -f /tmp/snap2.send -p $MNT/snap1 $MNT/snap2
# Now unmount the filesystem, create a new one, mount it and try to apply
# both send streams to recreate both snapshots.
umount $DEV
mkfs.btrfs -f $DEV >/dev/null
mount $DEV $MNT
btrfs receive -f /tmp/snap1.send $MNT
btrfs receive -f /tmp/snap2.send $MNT
umount $MNT
When running the test, the receive operation for the incremental stream
fails:
$ ./test-send-rmdir.sh
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap1'
At subvol /mnt/sdi/snap1
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap2'
At subvol /mnt/sdi/snap2
At subvol snap1
At snapshot snap2
ERROR: chown o257-9-0 failed: No such file or directory
So fix this by tracking directories that have a pending rmdir by inode
number and generation number, instead of only inode number.
A test case for fstests follows soon.
Reported-by: Massimo B. <massimo.b@gmx.net>
Tested-by: Massimo B. <massimo.b@gmx.net>
Link: https://lore.kernel.org/linux-btrfs/6ae34776e85912960a253a8327068a892998e685.camel@gmx.net/
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a chance of racing for qgroup flushing which may lead to
deadlock:
Thread A | Thread B
(not holding trans handle) | (holding a trans handle)
--------------------------------+--------------------------------
__btrfs_qgroup_reserve_meta() | __btrfs_qgroup_reserve_meta()
|- try_flush_qgroup() | |- try_flush_qgroup()
|- QGROUP_FLUSHING bit set | |
| | |- test_and_set_bit()
| | |- wait_event()
|- btrfs_join_transaction() |
|- btrfs_commit_transaction()|
!!! DEAD LOCK !!!
Since thread A wants to commit transaction, but thread B is holding a
transaction handle, blocking the commit.
At the same time, thread B is waiting for thread A to finish its commit.
This is just a hot fix, and would lead to more EDQUOT when we're near
the qgroup limit.
The proper fix would be to make all metadata/data reservations happen
without holding a transaction handle.
CC: stable@vger.kernel.org # 5.9+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.
item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.
When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.
And split_leaf return EOVERFLOW from following code:
if (extend && data_size + btrfs_item_size_nr(l, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.
However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:
data_size = sizeof(*di) + name_len;
if (data_size + btrfs_item_size_nr(leaf, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.
The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly
[436149.586170] ------------[ cut here ]------------
[436149.586173] BTRFS: Transaction aborted (error -75)
[436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G D 4.18.0-rc5+ #1
[436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
[436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
[436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
[436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
[436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
[436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
[436149.586260] FS: 00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
[436149.586261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
[436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[436149.586296] Call Trace:
[436149.586311] vfs_rename+0x383/0x920
[436149.586313] ? vfs_rename+0x383/0x920
[436149.586315] do_renameat2+0x4ca/0x590
[436149.586317] __x64_sys_rename+0x20/0x30
[436149.586324] do_syscall_64+0x5a/0x120
[436149.586330] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[436149.586332] RIP: 0033:0x7fa3133b1d37
[436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
[436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
[436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
[436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00
Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction. It simply
creates files and rename them to forged names that leads to
hash collision.
There are two ways to fix this. One is to simply revert the patch
878f2d2cb3 ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.
The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.
1. extent-tree.c: lookup_inline_extent_backref
2. file-item.c: btrfs_csum_file_blocks
to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.
This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When cloning an inline extent there are cases where we can not just copy
the inline extent from the source range to the target range (e.g. when the
target range starts at an offset greater than zero). In such cases we copy
the inline extent's data into a page of the destination inode and then
dirty that page. However, after that we will need to start a transaction
for each processed extent and, if we are ever low on available metadata
space, we may need to flush existing delalloc for all dirty inodes in an
attempt to release metadata space - if that happens we may deadlock:
* the async reclaim task queued a delalloc work to flush delalloc for
the destination inode of the clone operation;
* the task executing that delalloc work gets blocked waiting for the
range with the dirty page to be unlocked, which is currently locked
by the task doing the clone operation;
* the async reclaim task blocks waiting for the delalloc work to complete;
* the cloning task is waiting on the waitqueue of its reservation ticket
while holding the range with the dirty page locked in the inode's
io_tree;
* if metadata space is not released by some other task (like delalloc for
some other inode completing for example), the clone task waits forever
and as a consequence the delalloc work and async reclaim tasks will hang
forever as well. Releasing more space on the other hand may require
starting a transaction, which will hang as well when trying to reserve
metadata space, resulting in a deadlock between all these tasks.
When this happens, traces like the following show up in dmesg/syslog:
[87452.323003] INFO: task kworker/u16:11:1810830 blocked for more than 120 seconds.
[87452.323644] Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
[87452.324248] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[87452.324852] task:kworker/u16:11 state:D stack: 0 pid:1810830 ppid: 2 flags:0x00004000
[87452.325520] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[87452.326136] Call Trace:
[87452.326737] __schedule+0x5d1/0xcf0
[87452.327390] schedule+0x45/0xe0
[87452.328174] lock_extent_bits+0x1e6/0x2d0 [btrfs]
[87452.328894] ? finish_wait+0x90/0x90
[87452.329474] btrfs_invalidatepage+0x32c/0x390 [btrfs]
[87452.330133] ? __mod_memcg_state+0x8e/0x160
[87452.330738] __extent_writepage+0x2d4/0x400 [btrfs]
[87452.331405] extent_write_cache_pages+0x2b2/0x500 [btrfs]
[87452.332007] ? lock_release+0x20e/0x4c0
[87452.332557] ? trace_hardirqs_on+0x1b/0xf0
[87452.333127] extent_writepages+0x43/0x90 [btrfs]
[87452.333653] ? lock_acquire+0x1a3/0x490
[87452.334177] do_writepages+0x43/0xe0
[87452.334699] ? __filemap_fdatawrite_range+0xa4/0x100
[87452.335720] __filemap_fdatawrite_range+0xc5/0x100
[87452.336500] btrfs_run_delalloc_work+0x17/0x40 [btrfs]
[87452.337216] btrfs_work_helper+0xf1/0x600 [btrfs]
[87452.337838] process_one_work+0x24e/0x5e0
[87452.338437] worker_thread+0x50/0x3b0
[87452.339137] ? process_one_work+0x5e0/0x5e0
[87452.339884] kthread+0x153/0x170
[87452.340507] ? kthread_mod_delayed_work+0xc0/0xc0
[87452.341153] ret_from_fork+0x22/0x30
[87452.341806] INFO: task kworker/u16:1:2426217 blocked for more than 120 seconds.
[87452.342487] Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
[87452.343274] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[87452.344049] task:kworker/u16:1 state:D stack: 0 pid:2426217 ppid: 2 flags:0x00004000
[87452.344974] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
[87452.345655] Call Trace:
[87452.346305] __schedule+0x5d1/0xcf0
[87452.346947] ? kvm_clock_read+0x14/0x30
[87452.347676] ? wait_for_completion+0x81/0x110
[87452.348389] schedule+0x45/0xe0
[87452.349077] schedule_timeout+0x30c/0x580
[87452.349718] ? _raw_spin_unlock_irqrestore+0x3c/0x60
[87452.350340] ? lock_acquire+0x1a3/0x490
[87452.351006] ? try_to_wake_up+0x7a/0xa20
[87452.351541] ? lock_release+0x20e/0x4c0
[87452.352040] ? lock_acquired+0x199/0x490
[87452.352517] ? wait_for_completion+0x81/0x110
[87452.353000] wait_for_completion+0xab/0x110
[87452.353490] start_delalloc_inodes+0x2af/0x390 [btrfs]
[87452.353973] btrfs_start_delalloc_roots+0x12d/0x250 [btrfs]
[87452.354455] flush_space+0x24f/0x660 [btrfs]
[87452.355063] btrfs_async_reclaim_metadata_space+0x1bb/0x480 [btrfs]
[87452.355565] process_one_work+0x24e/0x5e0
[87452.356024] worker_thread+0x20f/0x3b0
[87452.356487] ? process_one_work+0x5e0/0x5e0
[87452.356973] kthread+0x153/0x170
[87452.357434] ? kthread_mod_delayed_work+0xc0/0xc0
[87452.357880] ret_from_fork+0x22/0x30
(...)
< stack traces of several tasks waiting for the locks of the inodes of the
clone operation >
(...)
[92867.444138] RSP: 002b:00007ffc3371bbe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[92867.444624] RAX: ffffffffffffffda RBX: 00007ffc3371bea0 RCX: 00007f61efe73f97
[92867.445116] RDX: 0000000000000000 RSI: 0000560fbd5d7a40 RDI: 0000560fbd5d8960
[92867.445595] RBP: 00007ffc3371beb0 R08: 0000000000000001 R09: 0000000000000003
[92867.446070] R10: 00007ffc3371b996 R11: 0000000000000246 R12: 0000000000000000
[92867.446820] R13: 000000000000001f R14: 00007ffc3371bea0 R15: 00007ffc3371beb0
[92867.447361] task:fsstress state:D stack: 0 pid:2508238 ppid:2508153 flags:0x00004000
[92867.447920] Call Trace:
[92867.448435] __schedule+0x5d1/0xcf0
[92867.448934] ? _raw_spin_unlock_irqrestore+0x3c/0x60
[92867.449423] schedule+0x45/0xe0
[92867.449916] __reserve_bytes+0x4a4/0xb10 [btrfs]
[92867.450576] ? finish_wait+0x90/0x90
[92867.451202] btrfs_reserve_metadata_bytes+0x29/0x190 [btrfs]
[92867.451815] btrfs_block_rsv_add+0x1f/0x50 [btrfs]
[92867.452412] start_transaction+0x2d1/0x760 [btrfs]
[92867.453216] clone_copy_inline_extent+0x333/0x490 [btrfs]
[92867.453848] ? lock_release+0x20e/0x4c0
[92867.454539] ? btrfs_search_slot+0x9a7/0xc30 [btrfs]
[92867.455218] btrfs_clone+0x569/0x7e0 [btrfs]
[92867.455952] btrfs_clone_files+0xf6/0x150 [btrfs]
[92867.456588] btrfs_remap_file_range+0x324/0x3d0 [btrfs]
[92867.457213] do_clone_file_range+0xd4/0x1f0
[92867.457828] vfs_clone_file_range+0x4d/0x230
[92867.458355] ? lock_release+0x20e/0x4c0
[92867.458890] ioctl_file_clone+0x8f/0xc0
[92867.459377] do_vfs_ioctl+0x342/0x750
[92867.459913] __x64_sys_ioctl+0x62/0xb0
[92867.460377] do_syscall_64+0x33/0x80
[92867.460842] entry_SYSCALL_64_after_hwframe+0x44/0xa9
(...)
< stack traces of more tasks blocked on metadata reservation like the clone
task above, because the async reclaim task has deadlocked >
(...)
Another thing to notice is that the worker task that is deadlocked when
trying to flush the destination inode of the clone operation is at
btrfs_invalidatepage(). This is simply because the clone operation has a
destination offset greater than the i_size and we only update the i_size
of the destination file after cloning an extent (just like we do in the
buffered write path).
Since the async reclaim path uses btrfs_start_delalloc_roots() to trigger
the flushing of delalloc for all inodes that have delalloc, add a runtime
flag to an inode to signal it should not be flushed, and for inodes with
that flag set, start_delalloc_inodes() will simply skip them. When the
cloning code needs to dirty a page to copy an inline extent, set that flag
on the inode and then clear it when the clone operation finishes.
This could be sporadically triggered with test case generic/269 from
fstests, which exercises many fsstress processes running in parallel with
several dd processes filling up the entire filesystem.
CC: stable@vger.kernel.org # 5.9+
Fixes: 05a5a7621c ("Btrfs: implement full reflink support for inline extents")
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>
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Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"Another series of killing more code than what is being added, again
thanks to Christoph's relentless cleanups and tech debt tackling.
This contains:
- blk-iocost improvements (Baolin Wang)
- part0 iostat fix (Jeffle Xu)
- Disable iopoll for split bios (Jeffle Xu)
- block tracepoint cleanups (Christoph Hellwig)
- Merging of struct block_device and hd_struct (Christoph Hellwig)
- Rework/cleanup of how block device sizes are updated (Christoph
Hellwig)
- Simplification of gendisk lookup and removal of block device
aliasing (Christoph Hellwig)
- Block device ioctl cleanups (Christoph Hellwig)
- Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)
- Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)
- sbitmap improvements (Pavel Begunkov)
- Hybrid polling fix (Pavel Begunkov)
- bvec iteration improvements (Pavel Begunkov)
- Zone revalidation fixes (Damien Le Moal)
- blk-throttle limit fix (Yu Kuai)
- Various little fixes"
* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
blk-mq: fix msec comment from micro to milli seconds
blk-mq: update arg in comment of blk_mq_map_queue
blk-mq: add helper allocating tagset->tags
Revert "block: Fix a lockdep complaint triggered by request queue flushing"
nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
block: disable iopoll for split bio
block: Improve blk_revalidate_disk_zones() checks
sbitmap: simplify wrap check
sbitmap: replace CAS with atomic and
sbitmap: remove swap_lock
sbitmap: optimise sbitmap_deferred_clear()
blk-mq: skip hybrid polling if iopoll doesn't spin
blk-iocost: Factor out the base vrate change into a separate function
blk-iocost: Factor out the active iocgs' state check into a separate function
blk-iocost: Move the usage ratio calculation to the correct place
blk-iocost: Remove unnecessary advance declaration
blk-iocost: Fix some typos in comments
blktrace: fix up a kerneldoc comment
block: remove the request_queue to argument request based tracepoints
...
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Merge tag 'for-5.11-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"We have a mix of all kinds of changes, feature updates, core stuff,
performance improvements and lots of cleanups and preparatory changes.
User visible:
- export filesystem generation in sysfs
- new features for mount option 'rescue':
- what's currently supported is exported in sysfs
- 'ignorebadroots'/'ibadroots' - continue even if some essential
tree roots are not usable (extent, uuid, data reloc, device,
csum, free space)
- 'ignoredatacsums'/'idatacsums' - skip checksum verification on
data
- 'all' - now enables 'ignorebadroots' + 'ignoredatacsums' +
'nologreplay'
- export read mirror policy settings to sysfs, new policies will be
added in the future
- remove inode number cache feature (mount -o inode_cache), obsoleted
in 5.9
User visible fixes:
- async discard scheduling fixes on high loads
- update inode byte counter atomically so stat() does not report
wrong value in some cases
- free space tree fixes:
- correctly report status of v2 after remount
- clear v1 cache inodes when v2 is newly enabled after remount
Core:
- switch own tree lock implementation to standard rw semaphore:
- one-level lock nesting is not required anymore, the last use of
this was in free space that's now loaded asynchronously
- own implementation of adaptive spinning before taking mutex has
been part of rwsem
- performance seems to be better in general, much better (+tens
of percents) for some workloads
- lockdep does not complain
- finish direct IO conversion to iomap infrastructure, remove
temporary workaround for DSYNC after iomap API updates
- preparatory work to support data and metadata blocks smaller than
page:
- generalize code that assumes sectorsize == PAGE_SIZE, lots of
refactoring
- planned namely for 64K pages (eg. arm64, ppc64)
- scrub read-only support
- preparatory work for zoned allocation mode (SMR/ZBC/ZNS friendly):
- disable incompatible features
- round-robin superblock write
- free space cache (v1) is loaded asynchronously, remove tree path
recursion
- slightly improved time tacking for transaction kthread wake ups
Performance improvements (note that the numbers depend on load type or
other features and weren't run on the same machine):
- skip unnecessary work:
- do not start readahead for csum tree when scrubbing non-data
block groups
- do not start and wait for delalloc on snapshot roots on
transaction commit
- fix race when defragmenting leads to unnecessary IO
- dbench speedups (+throughput%/-max latency%):
- skip unnecessary searches for xattrs when logging an inode
(+10.8/-8.2)
- stop incrementing log batch when joining log transaction (1-2)
- unlock path before checking if extent is shared during nocow
writeback (+5.0/-20.5), on fio load +9.7% throughput/-9.8%
runtime
- several tree log improvements, eg. removing unnecessary
operations, fixing races that lead to additional work
(+12.7/-8.2)
- tree-checker error branches annotated with unlikely() (+3%
throughput)
Other:
- cleanups
- lockdep fixes
- more btrfs_inode conversions
- error variable cleanups"
* tag 'for-5.11-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (198 commits)
btrfs: scrub: allow scrub to work with subpage sectorsize
btrfs: scrub: support subpage data scrub
btrfs: scrub: support subpage tree block scrub
btrfs: scrub: always allocate one full page for one sector for RAID56
btrfs: scrub: reduce width of extent_len/stripe_len from 64 to 32 bits
btrfs: refactor btrfs_lookup_bio_sums to handle out-of-order bvecs
btrfs: remove btrfs_find_ordered_sum call from btrfs_lookup_bio_sums
btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors
btrfs: update num_extent_pages to support subpage sized extent buffer
btrfs: don't allow tree block to cross page boundary for subpage support
btrfs: calculate inline extent buffer page size based on page size
btrfs: factor out btree page submission code to a helper
btrfs: make btrfs_verify_data_csum follow sector size
btrfs: pass bio_offset to check_data_csum() directly
btrfs: rename bio_offset of extent_submit_bio_start_t to dio_file_offset
btrfs: fix lockdep warning when creating free space tree
btrfs: skip space_cache v1 setup when not using it
btrfs: remove free space items when disabling space cache v1
btrfs: warn when remount will not change the free space tree
btrfs: use superblock state to print space_cache mount option
...
- Consolidate all kmap_atomic() internals into a generic implementation
which builds the base for the kmap_local() API and make the
kmap_atomic() interface wrappers which handle the disabling/enabling of
preemption and pagefaults.
- Switch the storage from per-CPU to per task and provide scheduler
support for clearing mapping when scheduling out and restoring them
when scheduling back in.
- Merge the migrate_disable/enable() code, which is also part of the
scheduler pull request. This was required to make the kmap_local()
interface available which does not disable preemption when a mapping
is established. It has to disable migration instead to guarantee that
the virtual address of the mapped slot is the same accross preemption.
- Provide better debug facilities: guard pages and enforced utilization
of the mapping mechanics on 64bit systems when the architecture allows
it.
- Provide the new kmap_local() API which can now be used to cleanup the
kmap_atomic() usage sites all over the place. Most of the usage sites
do not require the implicit disabling of preemption and pagefaults so
the penalty on 64bit and 32bit non-highmem systems is removed and quite
some of the code can be simplified. A wholesale conversion is not
possible because some usage depends on the implicit side effects and
some need to be cleaned up because they work around these side effects.
The migrate disable side effect is only effective on highmem systems
and when enforced debugging is enabled. On 64bit and 32bit non-highmem
systems the overhead is completely avoided.
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Merge tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull kmap updates from Thomas Gleixner:
"The new preemtible kmap_local() implementation:
- Consolidate all kmap_atomic() internals into a generic
implementation which builds the base for the kmap_local() API and
make the kmap_atomic() interface wrappers which handle the
disabling/enabling of preemption and pagefaults.
- Switch the storage from per-CPU to per task and provide scheduler
support for clearing mapping when scheduling out and restoring them
when scheduling back in.
- Merge the migrate_disable/enable() code, which is also part of the
scheduler pull request. This was required to make the kmap_local()
interface available which does not disable preemption when a
mapping is established. It has to disable migration instead to
guarantee that the virtual address of the mapped slot is the same
across preemption.
- Provide better debug facilities: guard pages and enforced
utilization of the mapping mechanics on 64bit systems when the
architecture allows it.
- Provide the new kmap_local() API which can now be used to cleanup
the kmap_atomic() usage sites all over the place. Most of the usage
sites do not require the implicit disabling of preemption and
pagefaults so the penalty on 64bit and 32bit non-highmem systems is
removed and quite some of the code can be simplified. A wholesale
conversion is not possible because some usage depends on the
implicit side effects and some need to be cleaned up because they
work around these side effects.
The migrate disable side effect is only effective on highmem
systems and when enforced debugging is enabled. On 64bit and 32bit
non-highmem systems the overhead is completely avoided"
* tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
ARM: highmem: Fix cache_is_vivt() reference
x86/crashdump/32: Simplify copy_oldmem_page()
io-mapping: Provide iomap_local variant
mm/highmem: Provide kmap_local*
sched: highmem: Store local kmaps in task struct
x86: Support kmap_local() forced debugging
mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL
microblaze/mm/highmem: Add dropped #ifdef back
xtensa/mm/highmem: Make generic kmap_atomic() work correctly
mm/highmem: Take kmap_high_get() properly into account
highmem: High implementation details and document API
Documentation/io-mapping: Remove outdated blurb
io-mapping: Cleanup atomic iomap
mm/highmem: Remove the old kmap_atomic cruft
highmem: Get rid of kmap_types.h
xtensa/mm/highmem: Switch to generic kmap atomic
sparc/mm/highmem: Switch to generic kmap atomic
powerpc/mm/highmem: Switch to generic kmap atomic
nds32/mm/highmem: Switch to generic kmap atomic
...
Since btrfs scrub is utilizing its own infrastructure to submit
read/write, scrub is independent from all other routines.
This brings one very neat feature, allow us to read 4K data into offset
0 of a 64K page. So is the writeback routine.
This makes scrub on subpage sector size much easier to implement, and
thanks to previous commits which just changed the implementation to
always do scrub based on sector size, now scrub can handle subpage
filesystem without any problem.
This patch will just remove the restriction on
(sectorsize != PAGE_SIZE), to make scrub finally work on subpage
filesystems.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs scrub is more flexible than buffered data write path, as we can
read an unaligned subpage data into page offset 0.
This ability makes subpage support much easier, we just need to check
each scrub_page::page_len and ensure we only calculate hash for [0,
page_len) of a page.
There is a small thing to notice: for subpage case, we still do sector
by sector scrub. This means we will submit a read bio for each sector
to scrub, resulting in the same amount of read bios, just like on the 4K
page systems.
This behavior can be considered as a good thing, if we want everything
to be the same as 4K page systems. But this also means, we're wasting
the possibility to submit larger bio using 64K page size. This is
another problem to consider in the future.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To support subpage tree block scrub, scrub_checksum_tree_block() only
needs to learn 2 new tricks:
- Follow sector size
Now scrub_page only represents one sector, we need to follow it
properly.
- Run checksum on all sectors
Since scrub_page only represents one sector, we need to run checksum
on all sectors, not only (nodesize >> PAGE_SIZE).
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For scrub_pages() and scrub_pages_for_parity(), we currently allocate
one scrub_page structure for one page.
This is fine if we only read/write one sector one time. But for cases
like scrubbing RAID56, we need to read/write the full stripe, which is
in 64K size for now.
For subpage size, we will submit the read in just one page, which is
normally a good thing, but for RAID56 case, it only expects to see one
sector, not the full stripe in its endio function.
This could lead to wrong parity checksum for RAID56 on subpage.
To make the existing code work well for subpage case, here we take a
shortcut by always allocating a full page for one sector.
This should provide the base to make RAID56 work for subpage case.
The cost is pretty obvious now, for one RAID56 stripe now we always need
16 pages. For support subpage situation (64K page size, 4K sector size),
this means we need full one megabyte to scrub just one RAID56 stripe.
And for data scrub, each 4K sector will also need one 64K page.
This is mostly just a workaround, the proper fix for this is a much
larger project, using scrub_block to replace scrub_page, and allow
scrub_block to handle multi pages, csums, and csum_bitmap to avoid
allocating one page for each sector.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs on-disk format chose to use u64 for almost everything, but there
are a other restrictions that won't let us use more than u32 for things
like extent length (the maximum length is 128MiB for non-hole extents),
or stripe length (we have device number limit).
This means if we don't have extra handling to convert u64 to u32, we
will always have some questionable operations like
"u32 = u64 >> sectorsize_bits" in the code.
This patch will try to address the problem by reducing the width for the
following members/parameters:
- scrub_parity::stripe_len
- @len of scrub_pages()
- @extent_len of scrub_remap_extent()
- @len of scrub_parity_mark_sectors_error()
- @len of scrub_parity_mark_sectors_data()
- @len of scrub_extent()
- @len of scrub_pages_for_parity()
- @len of scrub_extent_for_parity()
For members extracted from on-disk structure, like map->stripe_len, they
will be kept as is. Since that modification would require on-disk format
change.
There will be cases like "u32 = u64 - u64" or "u32 = u64", for such call
sites, extra ASSERT() is added to be extra safe for debug builds.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Refactor btrfs_lookup_bio_sums() by:
- Remove the @file_offset parameter
There are two factors making the @file_offset parameter useless:
* For csum lookup in csum tree, file offset makes no sense
We only need disk_bytenr, which is unrelated to file_offset
* page_offset (file offset) of each bvec is not contiguous.
Pages can be added to the same bio as long as their on-disk bytenr
is contiguous, meaning we could have pages at different file offsets
in the same bio.
Thus passing file_offset makes no sense any more.
The only user of file_offset is for data reloc inode, we will use
a new function, search_file_offset_in_bio(), to handle it.
- Extract the csum tree lookup into search_csum_tree()
The new function will handle the csum search in csum tree.
The return value is the same as btrfs_find_ordered_sum(), returning
the number of found sectors which have checksum.
- Change how we do the main loop
The only needed info from bio is:
* the on-disk bytenr
* the length
After extracting the above info, we can do the search without bio
at all, which makes the main loop much simpler:
for (cur_disk_bytenr = orig_disk_bytenr;
cur_disk_bytenr < orig_disk_bytenr + orig_len;
cur_disk_bytenr += count * sectorsize) {
/* Lookup csum tree */
count = search_csum_tree(fs_info, path, cur_disk_bytenr,
search_len, csum_dst);
if (!count) {
/* Csum hole handling */
}
}
- Use single variable as the source to calculate all other offsets
Instead of all different type of variables, we use only one main
variable, cur_disk_bytenr, which represents the current disk bytenr.
All involved values can be calculated from that variable, and
all those variable will only be visible in the inner loop.
The above refactoring makes btrfs_lookup_bio_sums() way more robust than
it used to be, especially related to the file offset lookup. Now
file_offset lookup is only related to data reloc inode, otherwise we
don't need to bother file_offset at all.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function btrfs_lookup_bio_sums() is only called for read bios.
While btrfs_find_ordered_sum() is to search ordered extent sums, which
is only for write path.
This means to read a page we either:
- Submit read bio if it's not uptodate
This means we only need to search csum tree for checksums.
- The page is already uptodate
It can be marked uptodate for previous read, or being marked dirty.
As we always mark page uptodate for dirty page.
In that case, we don't need to submit read bio at all, thus no need
to search any checksums.
Remove the btrfs_find_ordered_sum() call in btrfs_lookup_bio_sums().
And since btrfs_lookup_bio_sums() is the only caller for
btrfs_find_ordered_sum(), also remove the implementation.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To support sectorsize < PAGE_SIZE case, we need to take extra care of
extent buffer accessors.
Since sectorsize is smaller than PAGE_SIZE, one page can contain
multiple tree blocks, we must use eb->start to determine the real offset
to read/write for extent buffer accessors.
This patch introduces two helpers to do this:
- get_eb_page_index()
This is to calculate the index to access extent_buffer::pages.
It's just a simple wrapper around "start >> PAGE_SHIFT".
For sectorsize == PAGE_SIZE case, nothing is changed.
For sectorsize < PAGE_SIZE case, we always get index as 0, and
the existing page shift also works.
- get_eb_offset_in_page()
This is to calculate the offset to access extent_buffer::pages.
This needs to take extent_buffer::start into consideration.
For sectorsize == PAGE_SIZE case, extent_buffer::start is always
aligned to PAGE_SIZE, thus adding extent_buffer::start to
offset_in_page() won't change the result.
For sectorsize < PAGE_SIZE case, adding extent_buffer::start gives
us the correct offset to access.
This patch will touch the following parts to cover all extent buffer
accessors:
- BTRFS_SETGET_HEADER_FUNCS()
- read_extent_buffer()
- read_extent_buffer_to_user()
- memcmp_extent_buffer()
- write_extent_buffer_chunk_tree_uuid()
- write_extent_buffer_fsid()
- write_extent_buffer()
- memzero_extent_buffer()
- copy_extent_buffer_full()
- copy_extent_buffer()
- memcpy_extent_buffer()
- memmove_extent_buffer()
- btrfs_get_token_##bits()
- btrfs_get_##bits()
- btrfs_set_token_##bits()
- btrfs_set_##bits()
- generic_bin_search()
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For subpage sized extent buffer, we have ensured no extent buffer will
cross page boundary, thus we would only need one page for any extent
buffer.
Update function num_extent_pages to handle such case. Now
num_extent_pages() returns 1 for subpage sized extent buffer.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As a preparation for subpage sector size support (allowing filesystem
with sector size smaller than page size to be mounted) if the sector
size is smaller than page size, we don't allow tree block to be read if
it crosses 64K(*) boundary.
The 64K is selected because:
- we are only going to support 64K page size for subpage for now
- 64K is also the maximum supported node size
This ensures that tree blocks are always contained in one page for a
system with 64K page size, which can greatly simplify the handling.
Otherwise we would have to do complex multi-page handling of tree
blocks. Currently there is no way to create such tree blocks.
In kernel we have avoided such tree blocks allocation even on 4K page
size, as it can lead to RAID56 stripe scrubbing.
While btrfs-progs have fixed its chunk allocator since 2016 for convert,
and has extra checks to do the same behavior as the kernel.
Just add such graceful checks in case of an ancient filesystem.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs only support 64K as maximum node size, thus for 4K page system, we
would have at most 16 pages for one extent buffer.
For a system using 64K page size, we would really have just one page.
While we always use 16 pages for extent_buffer::pages, this means for
systems using 64K pages, we are wasting memory for 15 page pointers
which will never be used.
Calculate the array size based on page size and the node size maximum.
- for systems using 4K page size, it will stay 16 pages
- for systems using 64K page size, it will be 1 page
Move the definition of BTRFS_MAX_METADATA_BLOCKSIZE to btrfs_tree.h, to
avoid circular inclusion of ctree.h.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btree_write_cache_pages() we have a btree page submission routine
buried deeply in a nested loop.
This patch will extract that part of code into a helper function,
submit_eb_page(), to do the same work.
Since submit_eb_page() now can return >0 for successful extent
buffer submission, remove the "ASSERT(ret <= 0);" line.
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>
Currently btrfs_verify_data_csum() just passes the whole page to
check_data_csum(), which is fine since we only support sectorsize ==
PAGE_SIZE.
To support subpage, we need to properly honor per-sector
checksum verification, just like what we did in dio read path.
This patch will do the csum verification in a for loop, starts with
pg_off == start - page_offset(page), with sectorsize increase for
each loop.
For sectorsize == PAGE_SIZE case, the pg_off will always be 0, and we
will only loop once.
For subpage case, we do the iterate over each sector and if we found any
error, we return error.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Parameter icsum for check_data_csum() is a little hard to understand.
So is the phy_offset for btrfs_verify_data_csum().
Both parameters are calculated values for csum lookup.
Instead of some calculated value, just pass bio_offset and let the
final and only user, check_data_csum(), calculate whatever it needs.
Since we are here, also make the bio_offset parameter and some related
variables to be u32 (unsigned int).
As bio size is limited by its bi_size, which is unsigned int, and has
extra size limit check during various bio operations.
Thus we are ensured that bio_offset won't overflow u32.
Thus for all involved functions, not only rename the parameter from
@phy_offset to @bio_offset, but also reduce its width to u32, so we
won't have suspicious "u32 = u64 >> sector_bits;" lines anymore.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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>
The parameter bio_offset of extent_submit_bio_start_t is very confusing.
If it's really bio_offset (offset to bio), then it should be u32. But
in fact, it's only utilized by dio read, and that member is used as file
offset, which must be u64.
Rename it to dio_file_offset since the only user uses it as file offset,
and add comment for who is using it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A lock dependency loop exists between the root tree lock, the extent tree
lock, and the free space tree lock.
The root tree lock depends on the free space tree lock because
btrfs_create_tree holds the new tree's lock while adding it to the root
tree.
The extent tree lock depends on the root tree lock because during
umount, we write out space cache v1, which writes inodes in the root
tree, which results in holding the root tree lock while doing a lookup
in the extent tree.
Finally, the free space tree depends on the extent tree because
populate_free_space_tree holds a locked path in the extent tree and then
does a lookup in the free space tree to add the new item.
The simplest of the three to break is the one during tree creation: we
unlock the leaf before inserting the tree node into the root tree, which
fixes the lockdep warning.
[30.480136] ======================================================
[30.480830] WARNING: possible circular locking dependency detected
[30.481457] 5.9.0-rc8+ #76 Not tainted
[30.481897] ------------------------------------------------------
[30.482500] mount/520 is trying to acquire lock:
[30.483064] ffff9babebe03908 (btrfs-free-space-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
[30.484054]
but task is already holding lock:
[30.484637] ffff9babebe24468 (btrfs-extent-01#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
[30.485581]
which lock already depends on the new lock.
[30.486397]
the existing dependency chain (in reverse order) is:
[30.487205]
-> #2 (btrfs-extent-01#2){++++}-{3:3}:
[30.487825] down_read_nested+0x43/0x150
[30.488306] __btrfs_tree_read_lock+0x39/0x180
[30.488868] __btrfs_read_lock_root_node+0x3a/0x50
[30.489477] btrfs_search_slot+0x464/0x9b0
[30.490009] check_committed_ref+0x59/0x1d0
[30.490603] btrfs_cross_ref_exist+0x65/0xb0
[30.491108] run_delalloc_nocow+0x405/0x930
[30.491651] btrfs_run_delalloc_range+0x60/0x6b0
[30.492203] writepage_delalloc+0xd4/0x150
[30.492688] __extent_writepage+0x18d/0x3a0
[30.493199] extent_write_cache_pages+0x2af/0x450
[30.493743] extent_writepages+0x34/0x70
[30.494231] do_writepages+0x31/0xd0
[30.494642] __filemap_fdatawrite_range+0xad/0xe0
[30.495194] btrfs_fdatawrite_range+0x1b/0x50
[30.495677] __btrfs_write_out_cache+0x40d/0x460
[30.496227] btrfs_write_out_cache+0x8b/0x110
[30.496716] btrfs_start_dirty_block_groups+0x211/0x4e0
[30.497317] btrfs_commit_transaction+0xc0/0xba0
[30.497861] sync_filesystem+0x71/0x90
[30.498303] btrfs_remount+0x81/0x433
[30.498767] reconfigure_super+0x9f/0x210
[30.499261] path_mount+0x9d1/0xa30
[30.499722] do_mount+0x55/0x70
[30.500158] __x64_sys_mount+0xc4/0xe0
[30.500616] do_syscall_64+0x33/0x40
[30.501091] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[30.501629]
-> #1 (btrfs-root-00){++++}-{3:3}:
[30.502241] down_read_nested+0x43/0x150
[30.502727] __btrfs_tree_read_lock+0x39/0x180
[30.503291] __btrfs_read_lock_root_node+0x3a/0x50
[30.503903] btrfs_search_slot+0x464/0x9b0
[30.504405] btrfs_insert_empty_items+0x60/0xa0
[30.504973] btrfs_insert_item+0x60/0xd0
[30.505412] btrfs_create_tree+0x1b6/0x210
[30.505913] btrfs_create_free_space_tree+0x54/0x110
[30.506460] btrfs_mount_rw+0x15d/0x20f
[30.506937] btrfs_remount+0x356/0x433
[30.507369] reconfigure_super+0x9f/0x210
[30.507868] path_mount+0x9d1/0xa30
[30.508264] do_mount+0x55/0x70
[30.508668] __x64_sys_mount+0xc4/0xe0
[30.509186] do_syscall_64+0x33/0x40
[30.509652] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[30.510271]
-> #0 (btrfs-free-space-00){++++}-{3:3}:
[30.510972] __lock_acquire+0x11ad/0x1b60
[30.511432] lock_acquire+0xa2/0x360
[30.511917] down_read_nested+0x43/0x150
[30.512383] __btrfs_tree_read_lock+0x39/0x180
[30.512947] __btrfs_read_lock_root_node+0x3a/0x50
[30.513455] btrfs_search_slot+0x464/0x9b0
[30.513947] search_free_space_info+0x45/0x90
[30.514465] __add_to_free_space_tree+0x92/0x39d
[30.515010] btrfs_create_free_space_tree.cold.22+0x1ee/0x45d
[30.515639] btrfs_mount_rw+0x15d/0x20f
[30.516142] btrfs_remount+0x356/0x433
[30.516538] reconfigure_super+0x9f/0x210
[30.517065] path_mount+0x9d1/0xa30
[30.517438] do_mount+0x55/0x70
[30.517824] __x64_sys_mount+0xc4/0xe0
[30.518293] do_syscall_64+0x33/0x40
[30.518776] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[30.519335]
other info that might help us debug this:
[30.520210] Chain exists of:
btrfs-free-space-00 --> btrfs-root-00 --> btrfs-extent-01#2
[30.521407] Possible unsafe locking scenario:
[30.522037] CPU0 CPU1
[30.522456] ---- ----
[30.522941] lock(btrfs-extent-01#2);
[30.523311] lock(btrfs-root-00);
[30.523952] lock(btrfs-extent-01#2);
[30.524620] lock(btrfs-free-space-00);
[30.525068]
*** DEADLOCK ***
[30.525669] 5 locks held by mount/520:
[30.526116] #0: ffff9babebc520e0 (&type->s_umount_key#37){+.+.}-{3:3}, at: path_mount+0x7ef/0xa30
[30.527056] #1: ffff9babebc52640 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x3d5/0x5c0
[30.527960] #2: ffff9babeae8f2e8 (&cache->free_space_lock#2){+.+.}-{3:3}, at: btrfs_create_free_space_tree.cold.22+0x101/0x45d
[30.529118] #3: ffff9babebe24468 (btrfs-extent-01#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
[30.530113] #4: ffff9babebd52eb8 (btrfs-extent-00){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x16/0x100
[30.531124]
stack backtrace:
[30.531528] CPU: 0 PID: 520 Comm: mount Not tainted 5.9.0-rc8+ #76
[30.532166] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-4.module_el8.1.0+248+298dec18 04/01/2014
[30.533215] Call Trace:
[30.533452] dump_stack+0x8d/0xc0
[30.533797] check_noncircular+0x13c/0x150
[30.534233] __lock_acquire+0x11ad/0x1b60
[30.534667] lock_acquire+0xa2/0x360
[30.535063] ? __btrfs_tree_read_lock+0x39/0x180
[30.535525] down_read_nested+0x43/0x150
[30.535939] ? __btrfs_tree_read_lock+0x39/0x180
[30.536400] __btrfs_tree_read_lock+0x39/0x180
[30.536862] __btrfs_read_lock_root_node+0x3a/0x50
[30.537304] btrfs_search_slot+0x464/0x9b0
[30.537713] ? trace_hardirqs_on+0x1c/0xf0
[30.538148] search_free_space_info+0x45/0x90
[30.538572] __add_to_free_space_tree+0x92/0x39d
[30.539071] ? printk+0x48/0x4a
[30.539367] btrfs_create_free_space_tree.cold.22+0x1ee/0x45d
[30.539972] btrfs_mount_rw+0x15d/0x20f
[30.540350] btrfs_remount+0x356/0x433
[30.540773] ? shrink_dcache_sb+0xd9/0x100
[30.541203] reconfigure_super+0x9f/0x210
[30.541642] path_mount+0x9d1/0xa30
[30.542040] do_mount+0x55/0x70
[30.542366] __x64_sys_mount+0xc4/0xe0
[30.542822] do_syscall_64+0x33/0x40
[30.543197] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[30.543691] RIP: 0033:0x7f109f7ab93a
[30.546042] RSP: 002b:00007ffc47c4f858 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
[30.546770] RAX: ffffffffffffffda RBX: 00007f109f8cf264 RCX: 00007f109f7ab93a
[30.547485] RDX: 0000557e6fc10770 RSI: 0000557e6fc19cf0 RDI: 0000557e6fc19cd0
[30.548185] RBP: 0000557e6fc10520 R08: 0000557e6fc18e30 R09: 0000557e6fc18cb0
[30.548911] R10: 0000000000200020 R11: 0000000000000246 R12: 0000000000000000
[30.549606] R13: 0000557e6fc19cd0 R14: 0000557e6fc10770 R15: 0000557e6fc10520
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
If we are not using space cache v1, we should not create the free space
object or free space inodes. This comes up when we delete the existing
free space objects/inodes when migrating to v2, only to see them get
recreated for every dirtied block group.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When the filesystem transitions from space cache v1 to v2 or to
nospace_cache, it removes the old cached data, but does not remove
the FREE_SPACE items nor the free space inodes they point to. This
doesn't cause any issues besides being a bit inefficient, since these
items no longer do anything useful.
To fix it, when we are mounting, and plan to disable the space cache,
destroy each block group's free space item and free space inode.
The code to remove the items is lifted from the existing use case of
removing the block group, with a light adaptation to handle whether or
not we have already looked up the free space inode.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
If the remount is ro->ro, rw->ro, or rw->rw, we will not create or
clear the free space tree. This can be surprising, so print a warning
to dmesg to make the failure more visible. It is also important to
ensure that the space cache options (SPACE_CACHE, FREE_SPACE_TREE) are
consistent, so ensure those are set to properly match the current on
disk state (which won't be changing).
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To make the contents of /proc/mounts better match the actual state of
the filesystem, base the display of the space cache mount options off
the contents of the super block rather than the last mount options
passed in. Since there are many scenarios where the mount will ignore a
space cache option, simply showing the passed in option is misleading.
For example, if we mount with -o remount,space_cache=v2 on a read-write
file system without an existing free space tree, we won't build a free
space tree, but /proc/mounts will read space_cache=v2 (until we mount
again and it goes away)
cache_generation is set iff space_cache=v1, FREE_SPACE_TREE is set iff
space_cache=v2, and if neither is the case, we print nospace_cache.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When mounting, btrfs uses the cache_generation in the super block to
determine if space cache v1 is in use. However, by mounting with
nospace_cache or space_cache=v2, it is possible to disable space cache
v1, which does not result in un-setting cache_generation back to 0.
In order to base some logic, like mount option printing in /proc/mounts,
on the current state of the space cache rather than just the values of
the mount option, keep the value of cache_generation consistent with the
status of space cache v1.
We ensure that cache_generation > 0 iff the file system is using
space_cache v1. This requires committing a transaction on any mount
which changes whether we are using v1. (v1->nospace_cache, v1->v2,
nospace_cache->v1, v2->v1).
Since the mechanism for writing out the cache generation is transaction
commit, but we want some finer grained control over when we un-set it,
we can't just rely on the SPACE_CACHE mount option, and introduce an
fs_info flag that mount can use when it wants to unset the generation.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
A user might want to revert to v1 or nospace_cache on a root filesystem,
and much like turning on the free space tree, that can only be done
remounting from ro->rw. Support clearing the free space tree on such
mounts by moving it into the shared remount logic.
Since the CLEAR_CACHE option sticks around across remounts, this change
would result in clearing the tree for ever on every remount, which is
not desirable. To fix that, add CLEAR_CACHE to the oneshot options we
clear at mount end, which has the other bonus of not cluttering the
/proc/mounts output with clear_cache.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Some options only apply during mount time and are cleared at the end
of mount. For now, the example is USEBACKUPROOT, but CLEAR_CACHE also
fits the bill, and this is a preparation patch for also clearing that
option.
One subtlety is that the current code only resets USEBACKUPROOT on rw
mounts, but the option is meaningfully "consumed" by a ro mount, so it
feels appropriate to clear in that case as well. A subsequent read-write
remount would not go through open_ctree, which is the only place that
checks the option, so the change should be benign.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a user attempts to remount a btrfs filesystem with
'mount -o remount,space_cache=v2', that operation silently succeeds.
Unfortunately, this is misleading, because the remount does not create
the free space tree. /proc/mounts will incorrectly show space_cache=v2,
but on the next mount, the file system will revert to the old
space_cache.
For now, we handle only the easier case, where the existing mount is
read-only and the new mount is read-write. In that case, we can create
the free space tree without contending with the block groups changing
as we go.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we attempt to create a free space tree while any block groups have
needs_free_space set, we will double add the new free space item
and hit EEXIST. Previously, we only created the free space tree on a new
mount, so we never hit the case, but if we try to create it on a
remount, such block groups could exist and trip us up.
We don't do anything with this field unless the free space tree is
enabled, so there is no harm in not setting it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
When we mount a rw filesystem, we start the orphan cleanup process in
tree root and filesystem tree. However, when we remount a ro file system
rw, we only clean the former. Move the calls to btrfs_orphan_cleanup()
on tree_root and fs_root to the shared rw mount routine to effectively
add them on ro->rw remount.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Mounting rw and remounting from ro to rw naturally share invariants and
functionality which result in a correctly setup rw filesystem. Luckily,
there is even a strong unity in the code which implements them. In
mount's open_ctree, these operations mostly happen after an early return
for ro file systems, and in remount, they happen in a section devoted to
remounting ro->rw, after some remount specific validation passes.
However, there are unfortunately a few differences. There are small
deviations in the order of some of the operations, remount does not
start orphan cleanup in root_tree or fs_tree, remount does not create
the free space tree, and remount does not handle "one-shot" mount
options like clear_cache and uuid tree rescan.
Since we want to add building the free space tree to remount, and also
to start the same orphan cleanup process on a filesystem mounted as ro
then remounted rw, we would benefit from unifying the logic between the
two code paths.
This patch only lifts the existing common functionality, and leaves a
natural path for fixing the discrepancies.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Linus Torvalds