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Quota disable ioctl starts a transaction before waiting for the qgroup
rescan worker completes. However, this wait can be infinite and results
in deadlock because of circular dependency among the quota disable
ioctl, the qgroup rescan worker and the other task with transaction such
as block group relocation task.
The deadlock happens with the steps following:
1) Task A calls ioctl to disable quota. It starts a transaction and
waits for qgroup rescan worker completes.
2) Task B such as block group relocation task starts a transaction and
joins to the transaction that task A started. Then task B commits to
the transaction. In this commit, task B waits for a commit by task A.
3) Task C as the qgroup rescan worker starts its job and starts a
transaction. In this transaction start, task C waits for completion
of the transaction that task A started and task B committed.
This deadlock was found with fstests test case btrfs/115 and a zoned
null_blk device. The test case enables and disables quota, and the
block group reclaim was triggered during the quota disable by chance.
The deadlock was also observed by running quota enable and disable in
parallel with 'btrfs balance' command on regular null_blk devices.
An example report of the deadlock:
[372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds.
[372.479944] Not tainted 5.16.0-rc8 #7
[372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[372.493898] task:kworker/u16:6 state:D stack: 0 pid: 103 ppid: 2 flags:0x00004000
[372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs]
[372.510782] Call Trace:
[372.514092] <TASK>
[372.521684] __schedule+0xb56/0x4850
[372.530104] ? io_schedule_timeout+0x190/0x190
[372.538842] ? lockdep_hardirqs_on+0x7e/0x100
[372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[372.555591] schedule+0xe0/0x270
[372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs]
[372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
[372.578875] ? free_unref_page+0x3f2/0x650
[372.585484] ? finish_wait+0x270/0x270
[372.591594] ? release_extent_buffer+0x224/0x420 [btrfs]
[372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs]
[372.607157] ? lock_release+0x3a9/0x6d0
[372.613054] ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs]
[372.620960] ? do_raw_spin_lock+0x11e/0x250
[372.627137] ? rwlock_bug.part.0+0x90/0x90
[372.633215] ? lock_is_held_type+0xe4/0x140
[372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs]
[372.646268] process_one_work+0x7e9/0x1320
[372.652321] ? lock_release+0x6d0/0x6d0
[372.658081] ? pwq_dec_nr_in_flight+0x230/0x230
[372.664513] ? rwlock_bug.part.0+0x90/0x90
[372.670529] worker_thread+0x59e/0xf90
[372.676172] ? process_one_work+0x1320/0x1320
[372.682440] kthread+0x3b9/0x490
[372.687550] ? _raw_spin_unlock_irq+0x24/0x50
[372.693811] ? set_kthread_struct+0x100/0x100
[372.700052] ret_from_fork+0x22/0x30
[372.705517] </TASK>
[372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds.
[372.729827] Not tainted 5.16.0-rc8 #7
[372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[372.767106] task:btrfs-transacti state:D stack: 0 pid: 2347 ppid: 2 flags:0x00004000
[372.787776] Call Trace:
[372.801652] <TASK>
[372.812961] __schedule+0xb56/0x4850
[372.830011] ? io_schedule_timeout+0x190/0x190
[372.852547] ? lockdep_hardirqs_on+0x7e/0x100
[372.871761] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[372.886792] schedule+0xe0/0x270
[372.901685] wait_current_trans+0x22c/0x310 [btrfs]
[372.919743] ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs]
[372.938923] ? finish_wait+0x270/0x270
[372.959085] ? join_transaction+0xc75/0xe30 [btrfs]
[372.977706] start_transaction+0x938/0x10a0 [btrfs]
[372.997168] transaction_kthread+0x19d/0x3c0 [btrfs]
[373.013021] ? btrfs_cleanup_transaction.isra.0+0xfc0/0xfc0 [btrfs]
[373.031678] kthread+0x3b9/0x490
[373.047420] ? _raw_spin_unlock_irq+0x24/0x50
[373.064645] ? set_kthread_struct+0x100/0x100
[373.078571] ret_from_fork+0x22/0x30
[373.091197] </TASK>
[373.105611] INFO: task btrfs:3145 blocked for more than 123 seconds.
[373.114147] Not tainted 5.16.0-rc8 #7
[373.120401] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[373.130393] task:btrfs state:D stack: 0 pid: 3145 ppid: 3141 flags:0x00004000
[373.140998] Call Trace:
[373.145501] <TASK>
[373.149654] __schedule+0xb56/0x4850
[373.155306] ? io_schedule_timeout+0x190/0x190
[373.161965] ? lockdep_hardirqs_on+0x7e/0x100
[373.168469] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[373.175468] schedule+0xe0/0x270
[373.180814] wait_for_commit+0x104/0x150 [btrfs]
[373.187643] ? test_and_set_bit+0x20/0x20 [btrfs]
[373.194772] ? kmem_cache_free+0x124/0x550
[373.201191] ? btrfs_put_transaction+0x69/0x3d0 [btrfs]
[373.208738] ? finish_wait+0x270/0x270
[373.214704] ? __btrfs_end_transaction+0x347/0x7b0 [btrfs]
[373.222342] btrfs_commit_transaction+0x44d/0x2610 [btrfs]
[373.230233] ? join_transaction+0x255/0xe30 [btrfs]
[373.237334] ? btrfs_record_root_in_trans+0x4d/0x170 [btrfs]
[373.245251] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
[373.253296] relocate_block_group+0x105/0xc20 [btrfs]
[373.260533] ? mutex_lock_io_nested+0x1270/0x1270
[373.267516] ? btrfs_wait_nocow_writers+0x85/0x180 [btrfs]
[373.275155] ? merge_reloc_roots+0x710/0x710 [btrfs]
[373.283602] ? btrfs_wait_ordered_extents+0xd30/0xd30 [btrfs]
[373.291934] ? kmem_cache_free+0x124/0x550
[373.298180] btrfs_relocate_block_group+0x35c/0x930 [btrfs]
[373.306047] btrfs_relocate_chunk+0x85/0x210 [btrfs]
[373.313229] btrfs_balance+0x12f4/0x2d20 [btrfs]
[373.320227] ? lock_release+0x3a9/0x6d0
[373.326206] ? btrfs_relocate_chunk+0x210/0x210 [btrfs]
[373.333591] ? lock_is_held_type+0xe4/0x140
[373.340031] ? rcu_read_lock_sched_held+0x3f/0x70
[373.346910] btrfs_ioctl_balance+0x548/0x700 [btrfs]
[373.354207] btrfs_ioctl+0x7f2/0x71b0 [btrfs]
[373.360774] ? lockdep_hardirqs_on_prepare+0x410/0x410
[373.367957] ? lockdep_hardirqs_on_prepare+0x410/0x410
[373.375327] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
[373.383841] ? find_held_lock+0x2c/0x110
[373.389993] ? lock_release+0x3a9/0x6d0
[373.395828] ? mntput_no_expire+0xf7/0xad0
[373.402083] ? lock_is_held_type+0xe4/0x140
[373.408249] ? vfs_fileattr_set+0x9f0/0x9f0
[373.414486] ? selinux_file_ioctl+0x349/0x4e0
[373.420938] ? trace_raw_output_lock+0xb4/0xe0
[373.427442] ? selinux_inode_getsecctx+0x80/0x80
[373.434224] ? lockdep_hardirqs_on+0x7e/0x100
[373.440660] ? force_qs_rnp+0x2a0/0x6b0
[373.446534] ? lock_is_held_type+0x9b/0x140
[373.452763] ? __blkcg_punt_bio_submit+0x1b0/0x1b0
[373.459732] ? security_file_ioctl+0x50/0x90
[373.466089] __x64_sys_ioctl+0x127/0x190
[373.472022] do_syscall_64+0x3b/0x90
[373.477513] entry_SYSCALL_64_after_hwframe+0x44/0xae
[373.484823] RIP: 0033:0x7f8f4af7e2bb
[373.490493] RSP: 002b:00007ffcbf936178 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[373.500197] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8f4af7e2bb
[373.509451] RDX: 00007ffcbf936220 RSI: 00000000c4009420 RDI: 0000000000000003
[373.518659] RBP: 00007ffcbf93774a R08: 0000000000000013 R09: 00007f8f4b02d4e0
[373.527872] R10: 00007f8f4ae87740 R11: 0000000000000246 R12: 0000000000000001
[373.537222] R13: 00007ffcbf936220 R14: 0000000000000000 R15: 0000000000000002
[373.546506] </TASK>
[373.550878] INFO: task btrfs:3146 blocked for more than 123 seconds.
[373.559383] Not tainted 5.16.0-rc8 #7
[373.565748] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[373.575748] task:btrfs state:D stack: 0 pid: 3146 ppid: 2168 flags:0x00000000
[373.586314] Call Trace:
[373.590846] <TASK>
[373.595121] __schedule+0xb56/0x4850
[373.600901] ? __lock_acquire+0x23db/0x5030
[373.607176] ? io_schedule_timeout+0x190/0x190
[373.613954] schedule+0xe0/0x270
[373.619157] schedule_timeout+0x168/0x220
[373.625170] ? usleep_range_state+0x150/0x150
[373.631653] ? mark_held_locks+0x9e/0xe0
[373.637767] ? do_raw_spin_lock+0x11e/0x250
[373.643993] ? lockdep_hardirqs_on_prepare+0x17b/0x410
[373.651267] ? _raw_spin_unlock_irq+0x24/0x50
[373.657677] ? lockdep_hardirqs_on+0x7e/0x100
[373.664103] wait_for_completion+0x163/0x250
[373.670437] ? bit_wait_timeout+0x160/0x160
[373.676585] btrfs_quota_disable+0x176/0x9a0 [btrfs]
[373.683979] ? btrfs_quota_enable+0x12f0/0x12f0 [btrfs]
[373.691340] ? down_write+0xd0/0x130
[373.696880] ? down_write_killable+0x150/0x150
[373.703352] btrfs_ioctl+0x3945/0x71b0 [btrfs]
[373.710061] ? find_held_lock+0x2c/0x110
[373.716192] ? lock_release+0x3a9/0x6d0
[373.722047] ? __handle_mm_fault+0x23cd/0x3050
[373.728486] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
[373.737032] ? set_pte+0x6a/0x90
[373.742271] ? do_raw_spin_unlock+0x55/0x1f0
[373.748506] ? lock_is_held_type+0xe4/0x140
[373.754792] ? vfs_fileattr_set+0x9f0/0x9f0
[373.761083] ? selinux_file_ioctl+0x349/0x4e0
[373.767521] ? selinux_inode_getsecctx+0x80/0x80
[373.774247] ? __up_read+0x182/0x6e0
[373.780026] ? count_memcg_events.constprop.0+0x46/0x60
[373.787281] ? up_write+0x460/0x460
[373.792932] ? security_file_ioctl+0x50/0x90
[373.799232] __x64_sys_ioctl+0x127/0x190
[373.805237] do_syscall_64+0x3b/0x90
[373.810947] entry_SYSCALL_64_after_hwframe+0x44/0xae
[373.818102] RIP: 0033:0x7f1383ea02bb
[373.823847] RSP: 002b:00007fffeb4d71f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[373.833641] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1383ea02bb
[373.842961] RDX: 00007fffeb4d7210 RSI: 00000000c0109428 RDI: 0000000000000003
[373.852179] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
[373.861408] R10: 00007f1383daec78 R11: 0000000000000202 R12: 00007fffeb4d874a
[373.870647] R13: 0000000000493099 R14: 0000000000000001 R15: 0000000000000000
[373.879838] </TASK>
[373.884018]
Showing all locks held in the system:
[373.894250] 3 locks held by kworker/4:1/58:
[373.900356] 1 lock held by khungtaskd/63:
[373.906333] #0: ffffffff8945ff60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260
[373.917307] 3 locks held by kworker/u16:6/103:
[373.923938] #0: ffff888127b4f138 ((wq_completion)btrfs-qgroup-rescan){+.+.}-{0:0}, at: process_one_work+0x712/0x1320
[373.936555] #1: ffff88810b817dd8 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x73f/0x1320
[373.951109] #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_qgroup_rescan_worker+0x1f6/0x10c0 [btrfs]
[373.964027] 2 locks held by less/1803:
[373.969982] #0: ffff88813ed56098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80
[373.981295] #1: ffffc90000b3b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9e2/0x1060
[373.992969] 1 lock held by btrfs-transacti/2347:
[373.999893] #0: ffff88813d4887a8 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0xe3/0x3c0 [btrfs]
[374.015872] 3 locks held by btrfs/3145:
[374.022298] #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl_balance+0xc3/0x700 [btrfs]
[374.034456] #1: ffff88813d48a0a0 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0xfe5/0x2d20 [btrfs]
[374.047646] #2: ffff88813d488838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x354/0x930 [btrfs]
[374.063295] 4 locks held by btrfs/3146:
[374.069647] #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl+0x38b1/0x71b0 [btrfs]
[374.081601] #1: ffff88813d488bb8 (&fs_info->subvol_sem){+.+.}-{3:3}, at: btrfs_ioctl+0x38fd/0x71b0 [btrfs]
[374.094283] #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_disable+0xc8/0x9a0 [btrfs]
[374.106885] #3: ffff88813d489800 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_disable+0xd5/0x9a0 [btrfs]
[374.126780] =============================================
To avoid the deadlock, wait for the qgroup rescan worker to complete
before starting the transaction for the quota disable ioctl. Clear
BTRFS_FS_QUOTA_ENABLE flag before the wait and the transaction to
request the worker to complete. On transaction start failure, set the
BTRFS_FS_QUOTA_ENABLE flag again. These BTRFS_FS_QUOTA_ENABLE flag
changes can be done safely since the function btrfs_quota_disable is not
called concurrently because of fs_info->subvol_sem.
Also check the BTRFS_FS_QUOTA_ENABLE flag in qgroup_rescan_init to avoid
another qgroup rescan worker to start after the previous qgroup worker
completed.
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When we start having multiple extent roots we'll need to use a helper to
get to the correct extent_root. Rename fs_info->extent_root to
_extent_root and convert all of the users of the extent root to using
the btrfs_extent_root() helper. This will allow us to easily clean up
the remaining direct accesses in the future.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:
- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;
- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.
This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.
Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.
When this deadlock happens, it produces a trace like the following:
INFO: task syz-executor:25604 blocked for more than 143 seconds.
Not tainted 5.15.0-rc6 #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4940 [inline]
__schedule+0xcd9/0x2530 kernel/sched/core.c:6287
schedule+0xd3/0x270 kernel/sched/core.c:6366
btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f86920b2c4d
RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
INFO: task syz-executor:25628 blocked for more than 143 seconds.
Not tainted 5.15.0-rc6 #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4940 [inline]
__schedule+0xcd9/0x2530 kernel/sched/core.c:6287
schedule+0xd3/0x270 kernel/sched/core.c:6366
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
__mutex_lock_common kernel/locking/mutex.c:669 [inline]
__mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa27f36 ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: stable@vger.kernel.org # 4.19
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When creating a subvolume, at ioctl.c:create_subvol(), if we fail to
insert the new root's root item into the root tree, we are freeing the
metadata extent we reserved for the new root to prevent a metadata
extent leak, as we don't abort the transaction at that point (since
there is nothing at that point that is irreversible).
However we allocated the metadata extent for the new root which we are
creating for the new subvolume, so its delayed reference refers to the
ID of this new root. But when we free the metadata extent we pass the
root of the subvolume where the new subvolume is located to
btrfs_free_tree_block() - this is incorrect because this will generate
a delayed reference that refers to the ID of the parent subvolume's root,
and not to ID of the new root.
This results in a failure when running delayed references that leads to
a transaction abort and a trace like the following:
[3868.738042] RIP: 0010:__btrfs_free_extent+0x709/0x950 [btrfs]
[3868.739857] Code: 68 0f 85 e6 fb ff (...)
[3868.742963] RSP: 0018:ffffb0e9045cf910 EFLAGS: 00010246
[3868.743908] RAX: 00000000fffffffe RBX: 00000000fffffffe RCX: 0000000000000002
[3868.745312] RDX: 00000000fffffffe RSI: 0000000000000002 RDI: ffff90b0cd793b88
[3868.746643] RBP: 000000000e5d8000 R08: 0000000000000000 R09: ffff90b0cd793b88
[3868.747979] R10: 0000000000000002 R11: 00014ded97944d68 R12: 0000000000000000
[3868.749373] R13: ffff90b09afe4a28 R14: 0000000000000000 R15: ffff90b0cd793b88
[3868.750725] FS: 00007f281c4a8b80(0000) GS:ffff90b3ada00000(0000) knlGS:0000000000000000
[3868.752275] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[3868.753515] CR2: 00007f281c6a5000 CR3: 0000000108a42006 CR4: 0000000000370ee0
[3868.754869] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[3868.756228] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[3868.757803] Call Trace:
[3868.758281] <TASK>
[3868.758655] ? btrfs_merge_delayed_refs+0x178/0x1c0 [btrfs]
[3868.759827] __btrfs_run_delayed_refs+0x2b1/0x1250 [btrfs]
[3868.761047] btrfs_run_delayed_refs+0x86/0x210 [btrfs]
[3868.762069] ? lock_acquired+0x19f/0x420
[3868.762829] btrfs_commit_transaction+0x69/0xb20 [btrfs]
[3868.763860] ? _raw_spin_unlock+0x29/0x40
[3868.764614] ? btrfs_block_rsv_release+0x1c2/0x1e0 [btrfs]
[3868.765870] create_subvol+0x1d8/0x9a0 [btrfs]
[3868.766766] btrfs_mksubvol+0x447/0x4c0 [btrfs]
[3868.767669] ? preempt_count_add+0x49/0xa0
[3868.768444] __btrfs_ioctl_snap_create+0x123/0x190 [btrfs]
[3868.769639] ? _copy_from_user+0x66/0xa0
[3868.770391] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[3868.771495] btrfs_ioctl+0xd1e/0x35c0 [btrfs]
[3868.772364] ? __slab_free+0x10a/0x360
[3868.773198] ? rcu_read_lock_sched_held+0x12/0x60
[3868.774121] ? lock_release+0x223/0x4a0
[3868.774863] ? lock_acquired+0x19f/0x420
[3868.775634] ? rcu_read_lock_sched_held+0x12/0x60
[3868.776530] ? trace_hardirqs_on+0x1b/0xe0
[3868.777373] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[3868.778280] ? kmem_cache_free+0x321/0x3c0
[3868.779011] ? __x64_sys_ioctl+0x83/0xb0
[3868.779718] __x64_sys_ioctl+0x83/0xb0
[3868.780387] do_syscall_64+0x3b/0xc0
[3868.781059] entry_SYSCALL_64_after_hwframe+0x44/0xae
[3868.781953] RIP: 0033:0x7f281c59e957
[3868.782585] Code: 3c 1c 48 f7 d8 4c (...)
[3868.785867] RSP: 002b:00007ffe1f83e2b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[3868.787198] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f281c59e957
[3868.788450] RDX: 00007ffe1f83e2c0 RSI: 0000000050009418 RDI: 0000000000000003
[3868.789748] RBP: 00007ffe1f83f300 R08: 0000000000000000 R09: 00007ffe1f83fe36
[3868.791214] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
[3868.792468] R13: 0000000000000003 R14: 00007ffe1f83e2c0 R15: 00000000000003cc
[3868.793765] </TASK>
[3868.794037] irq event stamp: 0
[3868.794548] hardirqs last enabled at (0): [<0000000000000000>] 0x0
[3868.795670] hardirqs last disabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040
[3868.797086] softirqs last enabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040
[3868.798309] softirqs last disabled at (0): [<0000000000000000>] 0x0
[3868.799284] ---[ end trace be24c7002fe27747 ]---
[3868.799928] BTRFS info (device dm-0): leaf 241188864 gen 1268 total ptrs 214 free space 469 owner 2
[3868.801133] BTRFS info (device dm-0): refs 2 lock_owner 225627 current 225627
[3868.802056] item 0 key (237436928 169 0) itemoff 16250 itemsize 33
[3868.802863] extent refs 1 gen 1265 flags 2
[3868.803447] ref#0: tree block backref root 1610
(...)
[3869.064354] item 114 key (241008640 169 0) itemoff 12488 itemsize 33
[3869.065421] extent refs 1 gen 1268 flags 2
[3869.066115] ref#0: tree block backref root 1689
(...)
[3869.403834] BTRFS error (device dm-0): unable to find ref byte nr 241008640 parent 0 root 1622 owner 0 offset 0
[3869.405641] BTRFS: error (device dm-0) in __btrfs_free_extent:3076: errno=-2 No such entry
[3869.407138] BTRFS: error (device dm-0) in btrfs_run_delayed_refs:2159: errno=-2 No such entry
Fix this by passing the new subvolume's root ID to btrfs_free_tree_block().
This requires changing the root argument of btrfs_free_tree_block() from
struct btrfs_root * to a u64, since at this point during the subvolume
creation we have not yet created the struct btrfs_root for the new
subvolume, and btrfs_free_tree_block() only needs a root ID and nothing
else from a struct btrfs_root.
This was triggered by test case generic/475 from fstests.
Fixes: 67addf29004c5b ("btrfs: fix metadata extent leak after failure to create subvolume")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently all the callers of btrfs_find_all_roots() pass a value of false
for its ignore_offset argument. This makes the argument pointless and we
can remove it and make btrfs_find_all_roots() always pass false as the
ignore_offset argument for btrfs_find_all_roots_safe(). So just do that.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
At btrfs_qgroup_trace_extent_post() we call btrfs_find_all_roots() with a
NULL value as the transaction handle argument, which makes that function
take the commit_root_sem semaphore, which is necessary when we don't hold
a transaction handle or any other mechanism to prevent a transaction
commit from wiping out commit roots.
However btrfs_qgroup_trace_extent_post() can be called in a context where
we are holding a write lock on an extent buffer from a subvolume tree,
namely from btrfs_truncate_inode_items(), called either during truncate
or unlink operations. In this case we end up with a lock inversion problem
because the commit_root_sem is a higher level lock, always supposed to be
acquired before locking any extent buffer.
Lockdep detects this lock inversion problem since we switched the extent
buffer locks from custom locks to semaphores, and when running btrfs/158
from fstests, it reported the following trace:
[ 9057.626435] ======================================================
[ 9057.627541] WARNING: possible circular locking dependency detected
[ 9057.628334] 5.14.0-rc2-btrfs-next-93 #1 Not tainted
[ 9057.628961] ------------------------------------------------------
[ 9057.629867] kworker/u16:4/30781 is trying to acquire lock:
[ 9057.630824] ffff8e2590f58760 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 9057.632542]
but task is already holding lock:
[ 9057.633551] ffff8e25582d4b70 (&fs_info->commit_root_sem){++++}-{3:3}, at: iterate_extent_inodes+0x10b/0x280 [btrfs]
[ 9057.635255]
which lock already depends on the new lock.
[ 9057.636292]
the existing dependency chain (in reverse order) is:
[ 9057.637240]
-> #1 (&fs_info->commit_root_sem){++++}-{3:3}:
[ 9057.638138] down_read+0x46/0x140
[ 9057.638648] btrfs_find_all_roots+0x41/0x80 [btrfs]
[ 9057.639398] btrfs_qgroup_trace_extent_post+0x37/0x70 [btrfs]
[ 9057.640283] btrfs_add_delayed_data_ref+0x418/0x490 [btrfs]
[ 9057.641114] btrfs_free_extent+0x35/0xb0 [btrfs]
[ 9057.641819] btrfs_truncate_inode_items+0x424/0xf70 [btrfs]
[ 9057.642643] btrfs_evict_inode+0x454/0x4f0 [btrfs]
[ 9057.643418] evict+0xcf/0x1d0
[ 9057.643895] do_unlinkat+0x1e9/0x300
[ 9057.644525] do_syscall_64+0x3b/0xc0
[ 9057.645110] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 9057.645835]
-> #0 (btrfs-tree-00){++++}-{3:3}:
[ 9057.646600] __lock_acquire+0x130e/0x2210
[ 9057.647248] lock_acquire+0xd7/0x310
[ 9057.647773] down_read_nested+0x4b/0x140
[ 9057.648350] __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 9057.649175] btrfs_read_lock_root_node+0x31/0x40 [btrfs]
[ 9057.650010] btrfs_search_slot+0x537/0xc00 [btrfs]
[ 9057.650849] scrub_print_warning_inode+0x89/0x370 [btrfs]
[ 9057.651733] iterate_extent_inodes+0x1e3/0x280 [btrfs]
[ 9057.652501] scrub_print_warning+0x15d/0x2f0 [btrfs]
[ 9057.653264] scrub_handle_errored_block.isra.0+0x135f/0x1640 [btrfs]
[ 9057.654295] scrub_bio_end_io_worker+0x101/0x2e0 [btrfs]
[ 9057.655111] btrfs_work_helper+0xf8/0x400 [btrfs]
[ 9057.655831] process_one_work+0x247/0x5a0
[ 9057.656425] worker_thread+0x55/0x3c0
[ 9057.656993] kthread+0x155/0x180
[ 9057.657494] ret_from_fork+0x22/0x30
[ 9057.658030]
other info that might help us debug this:
[ 9057.659064] Possible unsafe locking scenario:
[ 9057.659824] CPU0 CPU1
[ 9057.660402] ---- ----
[ 9057.660988] lock(&fs_info->commit_root_sem);
[ 9057.661581] lock(btrfs-tree-00);
[ 9057.662348] lock(&fs_info->commit_root_sem);
[ 9057.663254] lock(btrfs-tree-00);
[ 9057.663690]
*** DEADLOCK ***
[ 9057.664437] 4 locks held by kworker/u16:4/30781:
[ 9057.665023] #0: ffff8e25922a1148 ((wq_completion)btrfs-scrub){+.+.}-{0:0}, at: process_one_work+0x1c7/0x5a0
[ 9057.666260] #1: ffffabb3451ffe70 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x1c7/0x5a0
[ 9057.667639] #2: ffff8e25922da198 (&ret->mutex){+.+.}-{3:3}, at: scrub_handle_errored_block.isra.0+0x5d2/0x1640 [btrfs]
[ 9057.669017] #3: ffff8e25582d4b70 (&fs_info->commit_root_sem){++++}-{3:3}, at: iterate_extent_inodes+0x10b/0x280 [btrfs]
[ 9057.670408]
stack backtrace:
[ 9057.670976] CPU: 7 PID: 30781 Comm: kworker/u16:4 Not tainted 5.14.0-rc2-btrfs-next-93 #1
[ 9057.672030] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 9057.673492] Workqueue: btrfs-scrub btrfs_work_helper [btrfs]
[ 9057.674258] Call Trace:
[ 9057.674588] dump_stack_lvl+0x57/0x72
[ 9057.675083] check_noncircular+0xf3/0x110
[ 9057.675611] __lock_acquire+0x130e/0x2210
[ 9057.676132] lock_acquire+0xd7/0x310
[ 9057.676605] ? __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 9057.677313] ? lock_is_held_type+0xe8/0x140
[ 9057.677849] down_read_nested+0x4b/0x140
[ 9057.678349] ? __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 9057.679068] __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 9057.679760] btrfs_read_lock_root_node+0x31/0x40 [btrfs]
[ 9057.680458] btrfs_search_slot+0x537/0xc00 [btrfs]
[ 9057.681083] ? _raw_spin_unlock+0x29/0x40
[ 9057.681594] ? btrfs_find_all_roots_safe+0x11f/0x140 [btrfs]
[ 9057.682336] scrub_print_warning_inode+0x89/0x370 [btrfs]
[ 9057.683058] ? btrfs_find_all_roots_safe+0x11f/0x140 [btrfs]
[ 9057.683834] ? scrub_write_block_to_dev_replace+0xb0/0xb0 [btrfs]
[ 9057.684632] iterate_extent_inodes+0x1e3/0x280 [btrfs]
[ 9057.685316] scrub_print_warning+0x15d/0x2f0 [btrfs]
[ 9057.685977] ? ___ratelimit+0xa4/0x110
[ 9057.686460] scrub_handle_errored_block.isra.0+0x135f/0x1640 [btrfs]
[ 9057.687316] scrub_bio_end_io_worker+0x101/0x2e0 [btrfs]
[ 9057.688021] btrfs_work_helper+0xf8/0x400 [btrfs]
[ 9057.688649] ? lock_is_held_type+0xe8/0x140
[ 9057.689180] process_one_work+0x247/0x5a0
[ 9057.689696] worker_thread+0x55/0x3c0
[ 9057.690175] ? process_one_work+0x5a0/0x5a0
[ 9057.690731] kthread+0x155/0x180
[ 9057.691158] ? set_kthread_struct+0x40/0x40
[ 9057.691697] ret_from_fork+0x22/0x30
Fix this by making btrfs_find_all_roots() never attempt to lock the
commit_root_sem when it is called from btrfs_qgroup_trace_extent_post().
We can't just pass a non-NULL transaction handle to btrfs_find_all_roots()
from btrfs_qgroup_trace_extent_post(), because that would make backref
lookup not use commit roots and acquire read locks on extent buffers, and
therefore could deadlock when btrfs_qgroup_trace_extent_post() is called
from the btrfs_truncate_inode_items() code path which has acquired a write
lock on an extent buffer of the subvolume btree.
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When doing a send we don't expect the task to ever start a transaction
after the initial check that verifies if commit roots match the regular
roots. This is because after that we set current->journal_info with a
stub (special value) that signals we are in send context, so that we take
a read lock on an extent buffer when reading it from disk and verifying
it is valid (its generation matches the generation stored in the parent).
This stub was introduced in 2014 by commit a26e8c9f75b0bf ("Btrfs: don't
clear uptodate if the eb is under IO") in order to fix a concurrency issue
between send and balance.
However there is one particular exception where we end up needing to start
a transaction and when this happens it results in a crash with a stack
trace like the following:
[60015.902283] kernel: WARNING: CPU: 3 PID: 58159 at arch/x86/include/asm/kfence.h:44 kfence_protect_page+0x21/0x80
[60015.902292] kernel: Modules linked in: uinput rfcomm snd_seq_dummy (...)
[60015.902384] kernel: CPU: 3 PID: 58159 Comm: btrfs Not tainted 5.12.9-300.fc34.x86_64 #1
[60015.902387] kernel: Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./F2A88XN-WIFI, BIOS F6 12/24/2015
[60015.902389] kernel: RIP: 0010:kfence_protect_page+0x21/0x80
[60015.902393] kernel: Code: ff 0f 1f 84 00 00 00 00 00 55 48 89 fd (...)
[60015.902396] kernel: RSP: 0018:ffff9fb583453220 EFLAGS: 00010246
[60015.902399] kernel: RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9fb583453224
[60015.902401] kernel: RDX: ffff9fb583453224 RSI: 0000000000000000 RDI: 0000000000000000
[60015.902402] kernel: RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[60015.902404] kernel: R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
[60015.902406] kernel: R13: ffff9fb583453348 R14: 0000000000000000 R15: 0000000000000001
[60015.902408] kernel: FS: 00007f158e62d8c0(0000) GS:ffff93bd37580000(0000) knlGS:0000000000000000
[60015.902410] kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[60015.902412] kernel: CR2: 0000000000000039 CR3: 00000001256d2000 CR4: 00000000000506e0
[60015.902414] kernel: Call Trace:
[60015.902419] kernel: kfence_unprotect+0x13/0x30
[60015.902423] kernel: page_fault_oops+0x89/0x270
[60015.902427] kernel: ? search_module_extables+0xf/0x40
[60015.902431] kernel: ? search_bpf_extables+0x57/0x70
[60015.902435] kernel: kernelmode_fixup_or_oops+0xd6/0xf0
[60015.902437] kernel: __bad_area_nosemaphore+0x142/0x180
[60015.902440] kernel: exc_page_fault+0x67/0x150
[60015.902445] kernel: asm_exc_page_fault+0x1e/0x30
[60015.902450] kernel: RIP: 0010:start_transaction+0x71/0x580
[60015.902454] kernel: Code: d3 0f 84 92 00 00 00 80 e7 06 0f 85 63 (...)
[60015.902456] kernel: RSP: 0018:ffff9fb5834533f8 EFLAGS: 00010246
[60015.902458] kernel: RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
[60015.902460] kernel: RDX: 0000000000000801 RSI: 0000000000000000 RDI: 0000000000000039
[60015.902462] kernel: RBP: ffff93bc0a7eb800 R08: 0000000000000001 R09: 0000000000000000
[60015.902463] kernel: R10: 0000000000098a00 R11: 0000000000000001 R12: 0000000000000001
[60015.902464] kernel: R13: 0000000000000000 R14: ffff93bc0c92b000 R15: ffff93bc0c92b000
[60015.902468] kernel: btrfs_commit_inode_delayed_inode+0x5d/0x120
[60015.902473] kernel: btrfs_evict_inode+0x2c5/0x3f0
[60015.902476] kernel: evict+0xd1/0x180
[60015.902480] kernel: inode_lru_isolate+0xe7/0x180
[60015.902483] kernel: __list_lru_walk_one+0x77/0x150
[60015.902487] kernel: ? iput+0x1a0/0x1a0
[60015.902489] kernel: ? iput+0x1a0/0x1a0
[60015.902491] kernel: list_lru_walk_one+0x47/0x70
[60015.902495] kernel: prune_icache_sb+0x39/0x50
[60015.902497] kernel: super_cache_scan+0x161/0x1f0
[60015.902501] kernel: do_shrink_slab+0x142/0x240
[60015.902505] kernel: shrink_slab+0x164/0x280
[60015.902509] kernel: shrink_node+0x2c8/0x6e0
[60015.902512] kernel: do_try_to_free_pages+0xcb/0x4b0
[60015.902514] kernel: try_to_free_pages+0xda/0x190
[60015.902516] kernel: __alloc_pages_slowpath.constprop.0+0x373/0xcc0
[60015.902521] kernel: ? __memcg_kmem_charge_page+0xc2/0x1e0
[60015.902525] kernel: __alloc_pages_nodemask+0x30a/0x340
[60015.902528] kernel: pipe_write+0x30b/0x5c0
[60015.902531] kernel: ? set_next_entity+0xad/0x1e0
[60015.902534] kernel: ? switch_mm_irqs_off+0x58/0x440
[60015.902538] kernel: __kernel_write+0x13a/0x2b0
[60015.902541] kernel: kernel_write+0x73/0x150
[60015.902543] kernel: send_cmd+0x7b/0xd0
[60015.902545] kernel: send_extent_data+0x5a3/0x6b0
[60015.902549] kernel: process_extent+0x19b/0xed0
[60015.902551] kernel: btrfs_ioctl_send+0x1434/0x17e0
[60015.902554] kernel: ? _btrfs_ioctl_send+0xe1/0x100
[60015.902557] kernel: _btrfs_ioctl_send+0xbf/0x100
[60015.902559] kernel: ? enqueue_entity+0x18c/0x7b0
[60015.902562] kernel: btrfs_ioctl+0x185f/0x2f80
[60015.902564] kernel: ? psi_task_change+0x84/0xc0
[60015.902569] kernel: ? _flat_send_IPI_mask+0x21/0x40
[60015.902572] kernel: ? check_preempt_curr+0x2f/0x70
[60015.902576] kernel: ? selinux_file_ioctl+0x137/0x1e0
[60015.902579] kernel: ? expand_files+0x1cb/0x1d0
[60015.902582] kernel: ? __x64_sys_ioctl+0x82/0xb0
[60015.902585] kernel: __x64_sys_ioctl+0x82/0xb0
[60015.902588] kernel: do_syscall_64+0x33/0x40
[60015.902591] kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae
[60015.902595] kernel: RIP: 0033:0x7f158e38f0ab
[60015.902599] kernel: Code: ff ff ff 85 c0 79 9b (...)
[60015.902602] kernel: RSP: 002b:00007ffcb2519bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[60015.902605] kernel: RAX: ffffffffffffffda RBX: 00007ffcb251ae00 RCX: 00007f158e38f0ab
[60015.902607] kernel: RDX: 00007ffcb2519cf0 RSI: 0000000040489426 RDI: 0000000000000004
[60015.902608] kernel: RBP: 0000000000000004 R08: 00007f158e297640 R09: 00007f158e297640
[60015.902610] kernel: R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
[60015.902612] kernel: R13: 0000000000000002 R14: 00007ffcb251aee0 R15: 0000558c1a83e2a0
[60015.902615] kernel: ---[ end trace 7bbc33e23bb887ae ]---
This happens because when writing to the pipe, by calling kernel_write(),
we end up doing page allocations using GFP_HIGHUSER | __GFP_ACCOUNT as the
gfp flags, which allow reclaim to happen if there is memory pressure. This
allocation happens at fs/pipe.c:pipe_write().
If the reclaim is triggered, inode eviction can be triggered and that in
turn can result in starting a transaction if the inode has a link count
of 0. The transaction start happens early on during eviction, when we call
btrfs_commit_inode_delayed_inode() at btrfs_evict_inode(). This happens if
there is currently an open file descriptor for an inode with a link count
of 0 and the reclaim task gets a reference on the inode before that
descriptor is closed, in which case the reclaim task ends up doing the
final iput that triggers the inode eviction.
When we have assertions enabled (CONFIG_BTRFS_ASSERT=y), this triggers
the following assertion at transaction.c:start_transaction():
/* Send isn't supposed to start transactions. */
ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
And when assertions are not enabled, it triggers a crash since after that
assertion we cast current->journal_info into a transaction handle pointer
and then dereference it:
if (current->journal_info) {
WARN_ON(type & TRANS_EXTWRITERS);
h = current->journal_info;
refcount_inc(&h->use_count);
(...)
Which obviously results in a crash due to an invalid memory access.
The same type of issue can happen during other memory allocations we
do directly in the send code with kmalloc (and friends) as they use
GFP_KERNEL and therefore may trigger reclaim too, which started to
happen since 2016 after commit e780b0d1c1523e ("btrfs: send: use
GFP_KERNEL everywhere").
The issue could be solved by setting up a NOFS context for the entire
send operation so that reclaim could not be triggered when allocating
memory or pages through kernel_write(). However that is not very friendly
and we can in fact get rid of the send stub because:
1) The stub was introduced way back in 2014 by commit a26e8c9f75b0bf
("Btrfs: don't clear uptodate if the eb is under IO") to solve an
issue exclusive to when send and balance are running in parallel,
however there were other problems between balance and send and we do
not allow anymore to have balance and send run concurrently since
commit 9e967495e0e0ae ("Btrfs: prevent send failures and crashes due
to concurrent relocation"). More generically the issues are between
send and relocation, and that last commit eliminated only the
possibility of having send and balance run concurrently, but shrinking
a device also can trigger relocation, and on zoned filesystems we have
relocation of partially used block groups triggered automatically as
well. The previous patch that has a subject of:
"btrfs: ensure relocation never runs while we have send operations running"
Addresses all the remaining cases that can trigger relocation.
2) We can actually allow starting and even committing transactions while
in a send context if needed because send is not holding any locks that
would block the start or the commit of a transaction.
So get rid of all the logic added by commit a26e8c9f75b0bf ("Btrfs: don't
clear uptodate if the eb is under IO"). We can now always call
clear_extent_buffer_uptodate() at verify_parent_transid() since send is
the only case that uses commit roots without having a transaction open or
without holding the commit_root_sem.
Reported-by: Chris Murphy <lists@colorremedies.com>
Link: https://lore.kernel.org/linux-btrfs/CAJCQCtRQ57=qXo3kygwpwEBOU_CA_eKvdmjP52sU=eFvuVOEGw@mail.gmail.com/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Fix typos that have snuck in since the last round. Found by codespell.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There are a few exceptional cases where cloning an inline extent needs to
copy the inline extent data into a page of the destination inode.
When this happens, we end up starting a transaction while having a dirty
page for the destination inode and while having the range locked in the
destination's inode iotree too. Because when reserving metadata space
for a transaction we may need to flush existing delalloc in case there is
not enough free space, we have a mechanism in place to prevent a deadlock,
which was introduced in commit 3d45f221ce627d ("btrfs: fix deadlock when
cloning inline extent and low on free metadata space").
However when using qgroups, a transaction also reserves metadata qgroup
space, which can also result in flushing delalloc in case there is not
enough available space at the moment. When this happens we deadlock, since
flushing delalloc requires locking the file range in the inode's iotree
and the range was already locked at the very beginning of the clone
operation, before attempting to start the transaction.
When this issue happens, stack traces like the following are reported:
[72747.556262] task:kworker/u81:9 state:D stack: 0 pid: 225 ppid: 2 flags:0x00004000
[72747.556268] Workqueue: writeback wb_workfn (flush-btrfs-1142)
[72747.556271] Call Trace:
[72747.556273] __schedule+0x296/0x760
[72747.556277] schedule+0x3c/0xa0
[72747.556279] io_schedule+0x12/0x40
[72747.556284] __lock_page+0x13c/0x280
[72747.556287] ? generic_file_readonly_mmap+0x70/0x70
[72747.556325] extent_write_cache_pages+0x22a/0x440 [btrfs]
[72747.556331] ? __set_page_dirty_nobuffers+0xe7/0x160
[72747.556358] ? set_extent_buffer_dirty+0x5e/0x80 [btrfs]
[72747.556362] ? update_group_capacity+0x25/0x210
[72747.556366] ? cpumask_next_and+0x1a/0x20
[72747.556391] extent_writepages+0x44/0xa0 [btrfs]
[72747.556394] do_writepages+0x41/0xd0
[72747.556398] __writeback_single_inode+0x39/0x2a0
[72747.556403] writeback_sb_inodes+0x1ea/0x440
[72747.556407] __writeback_inodes_wb+0x5f/0xc0
[72747.556410] wb_writeback+0x235/0x2b0
[72747.556414] ? get_nr_inodes+0x35/0x50
[72747.556417] wb_workfn+0x354/0x490
[72747.556420] ? newidle_balance+0x2c5/0x3e0
[72747.556424] process_one_work+0x1aa/0x340
[72747.556426] worker_thread+0x30/0x390
[72747.556429] ? create_worker+0x1a0/0x1a0
[72747.556432] kthread+0x116/0x130
[72747.556435] ? kthread_park+0x80/0x80
[72747.556438] ret_from_fork+0x1f/0x30
[72747.566958] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[72747.566961] Call Trace:
[72747.566964] __schedule+0x296/0x760
[72747.566968] ? finish_wait+0x80/0x80
[72747.566970] schedule+0x3c/0xa0
[72747.566995] wait_extent_bit.constprop.68+0x13b/0x1c0 [btrfs]
[72747.566999] ? finish_wait+0x80/0x80
[72747.567024] lock_extent_bits+0x37/0x90 [btrfs]
[72747.567047] btrfs_invalidatepage+0x299/0x2c0 [btrfs]
[72747.567051] ? find_get_pages_range_tag+0x2cd/0x380
[72747.567076] __extent_writepage+0x203/0x320 [btrfs]
[72747.567102] extent_write_cache_pages+0x2bb/0x440 [btrfs]
[72747.567106] ? update_load_avg+0x7e/0x5f0
[72747.567109] ? enqueue_entity+0xf4/0x6f0
[72747.567134] extent_writepages+0x44/0xa0 [btrfs]
[72747.567137] ? enqueue_task_fair+0x93/0x6f0
[72747.567140] do_writepages+0x41/0xd0
[72747.567144] __filemap_fdatawrite_range+0xc7/0x100
[72747.567167] btrfs_run_delalloc_work+0x17/0x40 [btrfs]
[72747.567195] btrfs_work_helper+0xc2/0x300 [btrfs]
[72747.567200] process_one_work+0x1aa/0x340
[72747.567202] worker_thread+0x30/0x390
[72747.567205] ? create_worker+0x1a0/0x1a0
[72747.567208] kthread+0x116/0x130
[72747.567211] ? kthread_park+0x80/0x80
[72747.567214] ret_from_fork+0x1f/0x30
[72747.569686] task:fsstress state:D stack: 0 pid:841421 ppid:841417 flags:0x00000000
[72747.569689] Call Trace:
[72747.569691] __schedule+0x296/0x760
[72747.569694] schedule+0x3c/0xa0
[72747.569721] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569725] ? finish_wait+0x80/0x80
[72747.569753] btrfs_qgroup_reserve_data+0x34/0x50 [btrfs]
[72747.569781] btrfs_check_data_free_space+0x5f/0xa0 [btrfs]
[72747.569804] btrfs_buffered_write+0x1f7/0x7f0 [btrfs]
[72747.569810] ? path_lookupat.isra.48+0x97/0x140
[72747.569833] btrfs_file_write_iter+0x81/0x410 [btrfs]
[72747.569836] ? __kmalloc+0x16a/0x2c0
[72747.569839] do_iter_readv_writev+0x160/0x1c0
[72747.569843] do_iter_write+0x80/0x1b0
[72747.569847] vfs_writev+0x84/0x140
[72747.569869] ? btrfs_file_llseek+0x38/0x270 [btrfs]
[72747.569873] do_writev+0x65/0x100
[72747.569876] do_syscall_64+0x33/0x40
[72747.569879] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[72747.569899] task:fsstress state:D stack: 0 pid:841424 ppid:841417 flags:0x00004000
[72747.569903] Call Trace:
[72747.569906] __schedule+0x296/0x760
[72747.569909] schedule+0x3c/0xa0
[72747.569936] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569940] ? finish_wait+0x80/0x80
[72747.569967] __btrfs_qgroup_reserve_meta+0x36/0x50 [btrfs]
[72747.569989] start_transaction+0x279/0x580 [btrfs]
[72747.570014] clone_copy_inline_extent+0x332/0x490 [btrfs]
[72747.570041] btrfs_clone+0x5b7/0x7a0 [btrfs]
[72747.570068] ? lock_extent_bits+0x64/0x90 [btrfs]
[72747.570095] btrfs_clone_files+0xfc/0x150 [btrfs]
[72747.570122] btrfs_remap_file_range+0x3d8/0x4a0 [btrfs]
[72747.570126] do_clone_file_range+0xed/0x200
[72747.570131] vfs_clone_file_range+0x37/0x110
[72747.570134] ioctl_file_clone+0x7d/0xb0
[72747.570137] do_vfs_ioctl+0x138/0x630
[72747.570140] __x64_sys_ioctl+0x62/0xc0
[72747.570143] do_syscall_64+0x33/0x40
[72747.570146] entry_SYSCALL_64_after_hwframe+0x44/0xa9
So fix this by skipping the flush of delalloc for an inode that is
flagged with BTRFS_INODE_NO_DELALLOC_FLUSH, meaning it is currently under
such a special case of cloning an inline extent, when flushing delalloc
during qgroup metadata reservation.
The special cases for cloning inline extents were added in kernel 5.7 by
by commit 05a5a7621ce66c ("Btrfs: implement full reflink support for
inline extents"), while having qgroup metadata space reservation flushing
delalloc when low on space was added in kernel 5.9 by commit
c53e9653605dbf ("btrfs: qgroup: try to flush qgroup space when we get
-EDQUOT"). So use a "Fixes:" tag for the later commit to ease stable
kernel backports.
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Link: https://lore.kernel.org/linux-btrfs/20210421083137.31E3.409509F4@e16-tech.com/
Fixes: c53e9653605dbf ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
At qgroup.c:try_flush_qgroup() we are asserting that current->journal_info
is either NULL or has the value BTRFS_SEND_TRANS_STUB.
However allowing for BTRFS_SEND_TRANS_STUB makes no sense because:
1) It is misleading, because send operations are read-only and do not
ever need to reserve qgroup space;
2) We already assert that current->journal_info != BTRFS_SEND_TRANS_STUB
at transaction.c:start_transaction();
3) On a kernel without CONFIG_BTRFS_ASSERT=y set, it would result in
a crash if try_flush_qgroup() is ever called in a send context, because
at transaction.c:start_transaction we cast current->journal_info into
a struct btrfs_trans_handle pointer and then dereference it.
So just do allow a send context at try_flush_qgroup() and update the
comment about it.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The tree modification log, which records modifications done to btrees, is
quite large and currently spread all over ctree.c, which is a huge file
already.
To make things better organized, move all that code into its own separate
source and header files. Functions and definitions that are used outside
of the module (mostly by ctree.c) are renamed so that they start with a
"btrfs_" prefix. Everything else remains unchanged.
This makes it easier to go over the tree modification log code every
time I need to go read it to fix a bug.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
It's no longer expected to call this function with an open transaction
so all the workarounds concerning this can be removed. In fact it'll
constitute a bug to call this function with a transaction already held
so WARN in this case.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
While removing a qgroup's sysfs entry we end up taking the kernfs_mutex,
through kobject_del(), while holding the fs_info->qgroup_lock spinlock,
producing the following trace:
[821.843637] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:281
[821.843641] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 28214, name: podman
[821.843644] CPU: 3 PID: 28214 Comm: podman Tainted: G W 5.11.6 #15
[821.843646] Hardware name: Dell Inc. PowerEdge R330/084XW4, BIOS 2.11.0 12/08/2020
[821.843647] Call Trace:
[821.843650] dump_stack+0xa1/0xfb
[821.843656] ___might_sleep+0x144/0x160
[821.843659] mutex_lock+0x17/0x40
[821.843662] kernfs_remove_by_name_ns+0x1f/0x80
[821.843666] sysfs_remove_group+0x7d/0xe0
[821.843668] sysfs_remove_groups+0x28/0x40
[821.843670] kobject_del+0x2a/0x80
[821.843672] btrfs_sysfs_del_one_qgroup+0x2b/0x40 [btrfs]
[821.843685] __del_qgroup_rb+0x12/0x150 [btrfs]
[821.843696] btrfs_remove_qgroup+0x288/0x2a0 [btrfs]
[821.843707] btrfs_ioctl+0x3129/0x36a0 [btrfs]
[821.843717] ? __mod_lruvec_page_state+0x5e/0xb0
[821.843719] ? page_add_new_anon_rmap+0xbc/0x150
[821.843723] ? kfree+0x1b4/0x300
[821.843725] ? mntput_no_expire+0x55/0x330
[821.843728] __x64_sys_ioctl+0x5a/0xa0
[821.843731] do_syscall_64+0x33/0x70
[821.843733] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[821.843736] RIP: 0033:0x4cd3fb
[821.843741] RSP: 002b:000000c000906b20 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[821.843744] RAX: ffffffffffffffda RBX: 000000c000050000 RCX: 00000000004cd3fb
[821.843745] RDX: 000000c000906b98 RSI: 000000004010942a RDI: 000000000000000f
[821.843747] RBP: 000000c000907cd0 R08: 000000c000622901 R09: 0000000000000000
[821.843748] R10: 000000c000d992c0 R11: 0000000000000206 R12: 000000000000012d
[821.843749] R13: 000000000000012c R14: 0000000000000200 R15: 0000000000000049
Fix this by removing the qgroup sysfs entry while not holding the spinlock,
since the spinlock is only meant for protection of the qgroup rbtree.
Reported-by: Stuart Shelton <srcshelton@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/7A5485BB-0628-419D-A4D3-27B1AF47E25A@gmail.com/
Fixes: 49e5fb46211de0 ("btrfs: qgroup: export qgroups in sysfs")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
If we remount a filesystem in RO mode while the qgroup rescan worker is
running, we can end up having it still running after the remount is done,
and at unmount time we may end up with an open transaction that ends up
never getting committed. If that happens we end up with several memory
leaks and can crash when hardware acceleration is unavailable for crc32c.
Possibly it can lead to other nasty surprises too, due to use-after-free
issues.
The following steps explain how the problem happens.
1) We have a filesystem mounted in RW mode and the qgroup rescan worker is
running;
2) We remount the filesystem in RO mode, and never stop/pause the rescan
worker, so after the remount the rescan worker is still running. The
important detail here is that the rescan task is still running after
the remount operation committed any ongoing transaction through its
call to btrfs_commit_super();
3) The rescan is still running, and after the remount completed, the
rescan worker started a transaction, after it finished iterating all
leaves of the extent tree, to update the qgroup status item in the
quotas tree. It does not commit the transaction, it only releases its
handle on the transaction;
4) A filesystem unmount operation starts shortly after;
5) The unmount task, at close_ctree(), stops the transaction kthread,
which had not had a chance to commit the open transaction since it was
sleeping and the commit interval (default of 30 seconds) has not yet
elapsed since the last time it committed a transaction;
6) So after stopping the transaction kthread we still have the transaction
used to update the qgroup status item open. At close_ctree(), when the
filesystem is in RO mode and no transaction abort happened (or the
filesystem is in error mode), we do not expect to have any transaction
open, so we do not call btrfs_commit_super();
7) We then proceed to destroy the work queues, free the roots and block
groups, etc. After that we drop the last reference on the btree inode
by calling iput() on it. Since there are dirty pages for the btree
inode, corresponding to the COWed extent buffer for the quotas btree,
btree_write_cache_pages() is invoked to flush those dirty pages. This
results in creating a bio and submitting it, which makes us end up at
btrfs_submit_metadata_bio();
8) 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;
9) 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
Fix this issue by having the remount path stop the qgroup rescan worker
when we are remounting RO and teach the rescan worker to stop when a
remount is in progress. If later a remount in RW mode happens, we are
already resuming the qgroup rescan worker through the call to
btrfs_qgroup_rescan_resume(), so we do not need to worry about that.
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>
|
|
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>
|
|
In order to properly set the lockdep class of a newly allocated block we
need to know the owner of the block. For non-refcounted trees this is
straightforward, we always know in advance what tree we're reading from.
For refcounted trees we don't necessarily know, however all refcounted
trees share the same lockdep class name, tree-<level>.
Fix all the callers of read_tree_block() to pass in the root objectid
we're using. In places like relocation and backref we could probably
unconditionally use 0, but just in case use the root when we have it,
otherwise use 0 in the cases we don't have the root as it's going to be
a refcounted tree anyway.
This is a preparation patch for further changes.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We're open-coding btrfs_read_node_slot() here, replace with the helper.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We're open-coding btrfs_read_node_slot() here, replace with the helper.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We're open-coding btrfs_read_node_slot() here, replace with the helper.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We no longer distinguish between blocking and spinning, so rip out all
this code.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Now that we're using a rw_semaphore we no longer need to indicate if a
lock is blocking or not, nor do we need to flip the entire path from
blocking to spinning. Remove these helpers and all the places they are
called.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When running test case btrfs/017 from fstests, lockdep reported the
following splat:
[ 1297.067385] ======================================================
[ 1297.067708] WARNING: possible circular locking dependency detected
[ 1297.068022] 5.10.0-rc4-btrfs-next-73 #1 Not tainted
[ 1297.068322] ------------------------------------------------------
[ 1297.068629] btrfs/189080 is trying to acquire lock:
[ 1297.068929] ffff9f2725731690 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.069274]
but task is already holding lock:
[ 1297.069868] ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs]
[ 1297.070219]
which lock already depends on the new lock.
[ 1297.071131]
the existing dependency chain (in reverse order) is:
[ 1297.071721]
-> #1 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}:
[ 1297.072375] lock_acquire+0xd8/0x490
[ 1297.072710] __mutex_lock+0xa3/0xb30
[ 1297.073061] btrfs_qgroup_inherit+0x59/0x6a0 [btrfs]
[ 1297.073421] create_subvol+0x194/0x990 [btrfs]
[ 1297.073780] btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
[ 1297.074133] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
[ 1297.074498] btrfs_ioctl_snap_create+0x58/0x80 [btrfs]
[ 1297.074872] btrfs_ioctl+0x1a90/0x36f0 [btrfs]
[ 1297.075245] __x64_sys_ioctl+0x83/0xb0
[ 1297.075617] do_syscall_64+0x33/0x80
[ 1297.075993] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.076380]
-> #0 (sb_internal#2){.+.+}-{0:0}:
[ 1297.077166] check_prev_add+0x91/0xc60
[ 1297.077572] __lock_acquire+0x1740/0x3110
[ 1297.077984] lock_acquire+0xd8/0x490
[ 1297.078411] start_transaction+0x3c5/0x760 [btrfs]
[ 1297.078853] btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.079323] btrfs_ioctl+0x2c60/0x36f0 [btrfs]
[ 1297.079789] __x64_sys_ioctl+0x83/0xb0
[ 1297.080232] do_syscall_64+0x33/0x80
[ 1297.080680] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.081139]
other info that might help us debug this:
[ 1297.082536] Possible unsafe locking scenario:
[ 1297.083510] CPU0 CPU1
[ 1297.084005] ---- ----
[ 1297.084500] lock(&fs_info->qgroup_ioctl_lock);
[ 1297.084994] lock(sb_internal#2);
[ 1297.085485] lock(&fs_info->qgroup_ioctl_lock);
[ 1297.085974] lock(sb_internal#2);
[ 1297.086454]
*** DEADLOCK ***
[ 1297.087880] 3 locks held by btrfs/189080:
[ 1297.088324] #0: ffff9f2725731470 (sb_writers#14){.+.+}-{0:0}, at: btrfs_ioctl+0xa73/0x36f0 [btrfs]
[ 1297.088799] #1: ffff9f2702b60cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl+0x1f4d/0x36f0 [btrfs]
[ 1297.089284] #2: ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs]
[ 1297.089771]
stack backtrace:
[ 1297.090662] CPU: 5 PID: 189080 Comm: btrfs Not tainted 5.10.0-rc4-btrfs-next-73 #1
[ 1297.091132] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1297.092123] Call Trace:
[ 1297.092629] dump_stack+0x8d/0xb5
[ 1297.093115] check_noncircular+0xff/0x110
[ 1297.093596] check_prev_add+0x91/0xc60
[ 1297.094076] ? kvm_clock_read+0x14/0x30
[ 1297.094553] ? kvm_sched_clock_read+0x5/0x10
[ 1297.095029] __lock_acquire+0x1740/0x3110
[ 1297.095510] lock_acquire+0xd8/0x490
[ 1297.095993] ? btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.096476] start_transaction+0x3c5/0x760 [btrfs]
[ 1297.096962] ? btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.097451] btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.097941] ? btrfs_ioctl+0x1f4d/0x36f0 [btrfs]
[ 1297.098429] btrfs_ioctl+0x2c60/0x36f0 [btrfs]
[ 1297.098904] ? do_user_addr_fault+0x20c/0x430
[ 1297.099382] ? kvm_clock_read+0x14/0x30
[ 1297.099854] ? kvm_sched_clock_read+0x5/0x10
[ 1297.100328] ? sched_clock+0x5/0x10
[ 1297.100801] ? sched_clock_cpu+0x12/0x180
[ 1297.101272] ? __x64_sys_ioctl+0x83/0xb0
[ 1297.101739] __x64_sys_ioctl+0x83/0xb0
[ 1297.102207] do_syscall_64+0x33/0x80
[ 1297.102673] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.103148] RIP: 0033:0x7f773ff65d87
This is because during the quota enable ioctl we lock first the mutex
qgroup_ioctl_lock and then start a transaction, and starting a transaction
acquires a fs freeze semaphore (at the VFS level). However, every other
code path, except for the quota disable ioctl path, we do the opposite:
we start a transaction and then lock the mutex.
So fix this by making the quota enable and disable paths to start the
transaction without having the mutex locked, and then, after starting the
transaction, lock the mutex and check if some other task already enabled
or disabled the quotas, bailing with success if that was the case.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When adding or removing a qgroup relation we are doing a GFP_KERNEL
allocation which is not safe because we are holding a transaction
handle open and that can make us deadlock if the allocator needs to
recurse into the filesystem. So just surround those calls with a
nofs context.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Lockdep reported the following splat when running test btrfs/190 from
fstests:
[ 9482.126098] ======================================================
[ 9482.126184] WARNING: possible circular locking dependency detected
[ 9482.126281] 5.10.0-rc4-btrfs-next-73 #1 Not tainted
[ 9482.126365] ------------------------------------------------------
[ 9482.126456] mount/24187 is trying to acquire lock:
[ 9482.126534] ffffa0c869a7dac0 (&fs_info->qgroup_rescan_lock){+.+.}-{3:3}, at: qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.126647]
but task is already holding lock:
[ 9482.126777] ffffa0c892ebd3a0 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x120 [btrfs]
[ 9482.126886]
which lock already depends on the new lock.
[ 9482.127078]
the existing dependency chain (in reverse order) is:
[ 9482.127213]
-> #1 (btrfs-quota-00){++++}-{3:3}:
[ 9482.127366] lock_acquire+0xd8/0x490
[ 9482.127436] down_read_nested+0x45/0x220
[ 9482.127528] __btrfs_tree_read_lock+0x27/0x120 [btrfs]
[ 9482.127613] btrfs_read_lock_root_node+0x41/0x130 [btrfs]
[ 9482.127702] btrfs_search_slot+0x514/0xc30 [btrfs]
[ 9482.127788] update_qgroup_status_item+0x72/0x140 [btrfs]
[ 9482.127877] btrfs_qgroup_rescan_worker+0xde/0x680 [btrfs]
[ 9482.127964] btrfs_work_helper+0xf1/0x600 [btrfs]
[ 9482.128039] process_one_work+0x24e/0x5e0
[ 9482.128110] worker_thread+0x50/0x3b0
[ 9482.128181] kthread+0x153/0x170
[ 9482.128256] ret_from_fork+0x22/0x30
[ 9482.128327]
-> #0 (&fs_info->qgroup_rescan_lock){+.+.}-{3:3}:
[ 9482.128464] check_prev_add+0x91/0xc60
[ 9482.128551] __lock_acquire+0x1740/0x3110
[ 9482.128623] lock_acquire+0xd8/0x490
[ 9482.130029] __mutex_lock+0xa3/0xb30
[ 9482.130590] qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.131577] btrfs_read_qgroup_config+0x43a/0x550 [btrfs]
[ 9482.132175] open_ctree+0x1228/0x18a0 [btrfs]
[ 9482.132756] btrfs_mount_root.cold+0x13/0xed [btrfs]
[ 9482.133325] legacy_get_tree+0x30/0x60
[ 9482.133866] vfs_get_tree+0x28/0xe0
[ 9482.134392] fc_mount+0xe/0x40
[ 9482.134908] vfs_kern_mount.part.0+0x71/0x90
[ 9482.135428] btrfs_mount+0x13b/0x3e0 [btrfs]
[ 9482.135942] legacy_get_tree+0x30/0x60
[ 9482.136444] vfs_get_tree+0x28/0xe0
[ 9482.136949] path_mount+0x2d7/0xa70
[ 9482.137438] do_mount+0x75/0x90
[ 9482.137923] __x64_sys_mount+0x8e/0xd0
[ 9482.138400] do_syscall_64+0x33/0x80
[ 9482.138873] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 9482.139346]
other info that might help us debug this:
[ 9482.140735] Possible unsafe locking scenario:
[ 9482.141594] CPU0 CPU1
[ 9482.142011] ---- ----
[ 9482.142411] lock(btrfs-quota-00);
[ 9482.142806] lock(&fs_info->qgroup_rescan_lock);
[ 9482.143216] lock(btrfs-quota-00);
[ 9482.143629] lock(&fs_info->qgroup_rescan_lock);
[ 9482.144056]
*** DEADLOCK ***
[ 9482.145242] 2 locks held by mount/24187:
[ 9482.145637] #0: ffffa0c8411c40e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xb9/0x400
[ 9482.146061] #1: ffffa0c892ebd3a0 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x120 [btrfs]
[ 9482.146509]
stack backtrace:
[ 9482.147350] CPU: 1 PID: 24187 Comm: mount Not tainted 5.10.0-rc4-btrfs-next-73 #1
[ 9482.147788] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 9482.148709] Call Trace:
[ 9482.149169] dump_stack+0x8d/0xb5
[ 9482.149628] check_noncircular+0xff/0x110
[ 9482.150090] check_prev_add+0x91/0xc60
[ 9482.150561] ? kvm_clock_read+0x14/0x30
[ 9482.151017] ? kvm_sched_clock_read+0x5/0x10
[ 9482.151470] __lock_acquire+0x1740/0x3110
[ 9482.151941] ? __btrfs_tree_read_lock+0x27/0x120 [btrfs]
[ 9482.152402] lock_acquire+0xd8/0x490
[ 9482.152887] ? qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.153354] __mutex_lock+0xa3/0xb30
[ 9482.153826] ? qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.154301] ? qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.154768] ? qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.155226] qgroup_rescan_init+0x43/0xf0 [btrfs]
[ 9482.155690] btrfs_read_qgroup_config+0x43a/0x550 [btrfs]
[ 9482.156160] open_ctree+0x1228/0x18a0 [btrfs]
[ 9482.156643] btrfs_mount_root.cold+0x13/0xed [btrfs]
[ 9482.157108] ? rcu_read_lock_sched_held+0x5d/0x90
[ 9482.157567] ? kfree+0x31f/0x3e0
[ 9482.158030] legacy_get_tree+0x30/0x60
[ 9482.158489] vfs_get_tree+0x28/0xe0
[ 9482.158947] fc_mount+0xe/0x40
[ 9482.159403] vfs_kern_mount.part.0+0x71/0x90
[ 9482.159875] btrfs_mount+0x13b/0x3e0 [btrfs]
[ 9482.160335] ? rcu_read_lock_sched_held+0x5d/0x90
[ 9482.160805] ? kfree+0x31f/0x3e0
[ 9482.161260] ? legacy_get_tree+0x30/0x60
[ 9482.161714] legacy_get_tree+0x30/0x60
[ 9482.162166] vfs_get_tree+0x28/0xe0
[ 9482.162616] path_mount+0x2d7/0xa70
[ 9482.163070] do_mount+0x75/0x90
[ 9482.163525] __x64_sys_mount+0x8e/0xd0
[ 9482.163986] do_syscall_64+0x33/0x80
[ 9482.164437] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 9482.164902] RIP: 0033:0x7f51e907caaa
This happens because at btrfs_read_qgroup_config() we can call
qgroup_rescan_init() while holding a read lock on a quota btree leaf,
acquired by the previous call to btrfs_search_slot_for_read(), and
qgroup_rescan_init() acquires the mutex qgroup_rescan_lock.
A qgroup rescan worker does the opposite: it acquires the mutex
qgroup_rescan_lock, at btrfs_qgroup_rescan_worker(), and then tries to
update the qgroup status item in the quota btree through the call to
update_qgroup_status_item(). This inversion of locking order
between the qgroup_rescan_lock mutex and quota btree locks causes the
splat.
Fix this simply by releasing and freeing the path before calling
qgroup_rescan_init() at btrfs_read_qgroup_config().
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
[BUG]
When running the following script, btrfs will trigger an ASSERT():
#/bin/bash
mkfs.btrfs -f $dev
mount $dev $mnt
xfs_io -f -c "pwrite 0 1G" $mnt/file
sync
btrfs quota enable $mnt
btrfs quota rescan -w $mnt
# Manually set the limit below current usage
btrfs qgroup limit 512M $mnt $mnt
# Crash happens
touch $mnt/file
The dmesg looks like this:
assertion failed: refcount_read(&trans->use_count) == 1, in fs/btrfs/transaction.c:2022
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3230!
invalid opcode: 0000 [#1] SMP PTI
RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
btrfs_commit_transaction.cold+0x11/0x5d [btrfs]
try_flush_qgroup+0x67/0x100 [btrfs]
__btrfs_qgroup_reserve_meta+0x3a/0x60 [btrfs]
btrfs_delayed_update_inode+0xaa/0x350 [btrfs]
btrfs_update_inode+0x9d/0x110 [btrfs]
btrfs_dirty_inode+0x5d/0xd0 [btrfs]
touch_atime+0xb5/0x100
iterate_dir+0xf1/0x1b0
__x64_sys_getdents64+0x78/0x110
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fb5afe588db
[CAUSE]
In try_flush_qgroup(), we assume we don't hold a transaction handle at
all. This is true for data reservation and mostly true for metadata.
Since data space reservation always happens before we start a
transaction, and for most metadata operation we reserve space in
start_transaction().
But there is an exception, btrfs_delayed_inode_reserve_metadata().
It holds a transaction handle, while still trying to reserve extra
metadata space.
When we hit EDQUOT inside btrfs_delayed_inode_reserve_metadata(), we
will join current transaction and commit, while we still have
transaction handle from qgroup code.
[FIX]
Let's check current->journal before we join the transaction.
If current->journal is unset or BTRFS_SEND_TRANS_STUB, it means
we are not holding a transaction, thus are able to join and then commit
transaction.
If current->journal is a valid transaction handle, we avoid committing
transaction and just end it
This is less effective than committing current transaction, as it won't
free metadata reserved space, but we may still free some data space
before new data writes.
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1178634
Fixes: c53e9653605d ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Smatch complains that this code dereferences "entry" before checking
whether it's NULL on the next line. Fortunately, rb_entry() will never
return NULL so it doesn't cause a problem. We can clean up the NULL
checking a bit to silence the warning and make the code more clear.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When enabling qgroups we walk the tree_root and then add a qgroup item
for every root that we have. This creates a lock dependency on the
tree_root and qgroup_root, which results in the following lockdep splat
(with tree locks using rwsem), eg. in tests btrfs/017 or btrfs/022:
======================================================
WARNING: possible circular locking dependency detected
5.9.0-default+ #1299 Not tainted
------------------------------------------------------
btrfs/24552 is trying to acquire lock:
ffff9142dfc5f630 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
but task is already holding lock:
ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (btrfs-root-00){++++}-{3:3}:
__lock_acquire+0x3fb/0x730
lock_acquire.part.0+0x6a/0x130
down_read_nested+0x46/0x130
__btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
__btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
btrfs_search_slot+0xc3/0x9f0 [btrfs]
btrfs_insert_item+0x6e/0x140 [btrfs]
btrfs_create_tree+0x1cb/0x240 [btrfs]
btrfs_quota_enable+0xcd/0x790 [btrfs]
btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
__x64_sys_ioctl+0x83/0xa0
do_syscall_64+0x2d/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #0 (btrfs-quota-00){++++}-{3:3}:
check_prev_add+0x91/0xc30
validate_chain+0x491/0x750
__lock_acquire+0x3fb/0x730
lock_acquire.part.0+0x6a/0x130
down_read_nested+0x46/0x130
__btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
__btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
btrfs_search_slot+0xc3/0x9f0 [btrfs]
btrfs_insert_empty_items+0x58/0xa0 [btrfs]
add_qgroup_item.part.0+0x72/0x210 [btrfs]
btrfs_quota_enable+0x3bb/0x790 [btrfs]
btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
__x64_sys_ioctl+0x83/0xa0
do_syscall_64+0x2d/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(btrfs-root-00);
lock(btrfs-quota-00);
lock(btrfs-root-00);
lock(btrfs-quota-00);
*** DEADLOCK ***
5 locks held by btrfs/24552:
#0: ffff9142df431478 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0xa0
#1: ffff9142f9b10cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl_quota_ctl+0x7b/0xe0 [btrfs]
#2: ffff9142f9b11a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0x790 [btrfs]
#3: ffff9142df431698 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x406/0x510 [btrfs]
#4: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
stack backtrace:
CPU: 1 PID: 24552 Comm: btrfs Not tainted 5.9.0-default+ #1299
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
Call Trace:
dump_stack+0x77/0x97
check_noncircular+0xf3/0x110
check_prev_add+0x91/0xc30
validate_chain+0x491/0x750
__lock_acquire+0x3fb/0x730
lock_acquire.part.0+0x6a/0x130
? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
? lock_acquire+0xc4/0x140
? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
down_read_nested+0x46/0x130
? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
__btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
? btrfs_root_node+0xd9/0x200 [btrfs]
__btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
btrfs_search_slot+0xc3/0x9f0 [btrfs]
btrfs_insert_empty_items+0x58/0xa0 [btrfs]
add_qgroup_item.part.0+0x72/0x210 [btrfs]
btrfs_quota_enable+0x3bb/0x790 [btrfs]
btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
__x64_sys_ioctl+0x83/0xa0
do_syscall_64+0x2d/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by dropping the path whenever we find a root item, add the
qgroup item, and then re-lookup the root item we found and continue
processing roots.
Reported-by: David Sterba <dsterba@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Delete repeated words in fs/btrfs/.
{to, the, a, and old}
and change "into 2 part" to "into 2 parts".
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
retry-after-EDQUOT
commit a514d63882c3 ("btrfs: qgroup: Commit transaction in advance to
reduce early EDQUOT") tries to reduce the early EDQUOT problems by
checking the qgroup free against threshold and tries to wake up commit
kthread to free some space.
The problem of that mechanism is, it can only free qgroup per-trans
metadata space, can't do anything to data, nor prealloc qgroup space.
Now since we have the ability to flush qgroup space, and implemented
retry-after-EDQUOT behavior, such mechanism can be completely replaced.
So this patch will cleanup such mechanism in favor of
retry-after-EDQUOT.
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>
|
|
[PROBLEM]
There are known problem related to how btrfs handles qgroup reserved
space. One of the most obvious case is the the test case btrfs/153,
which do fallocate, then write into the preallocated range.
btrfs/153 1s ... - output mismatch (see xfstests-dev/results//btrfs/153.out.bad)
--- tests/btrfs/153.out 2019-10-22 15:18:14.068965341 +0800
+++ xfstests-dev/results//btrfs/153.out.bad 2020-07-01 20:24:40.730000089 +0800
@@ -1,2 +1,5 @@
QA output created by 153
+pwrite: Disk quota exceeded
+/mnt/scratch/testfile2: Disk quota exceeded
+/mnt/scratch/testfile2: Disk quota exceeded
Silence is golden
...
(Run 'diff -u xfstests-dev/tests/btrfs/153.out xfstests-dev/results//btrfs/153.out.bad' to see the entire diff)
[CAUSE]
Since commit c6887cd11149 ("Btrfs: don't do nocow check unless we have to"),
we always reserve space no matter if it's COW or not.
Such behavior change is mostly for performance, and reverting it is not
a good idea anyway.
For preallcoated extent, we reserve qgroup data space for it already,
and since we also reserve data space for qgroup at buffered write time,
it needs twice the space for us to write into preallocated space.
This leads to the -EDQUOT in buffered write routine.
And we can't follow the same solution, unlike data/meta space check,
qgroup reserved space is shared between data/metadata.
The EDQUOT can happen at the metadata reservation, so doing NODATACOW
check after qgroup reservation failure is not a solution.
[FIX]
To solve the problem, we don't return -EDQUOT directly, but every time
we got a -EDQUOT, we try to flush qgroup space:
- Flush all inodes of the root
NODATACOW writes will free the qgroup reserved at run_dealloc_range().
However we don't have the infrastructure to only flush NODATACOW
inodes, here we flush all inodes anyway.
- Wait for ordered extents
This would convert the preallocated metadata space into per-trans
metadata, which can be freed in later transaction commit.
- Commit transaction
This will free all per-trans metadata space.
Also we don't want to trigger flush multiple times, so here we introduce
a per-root wait list and a new root status, to ensure only one thread
starts the flushing.
Fixes: c6887cd11149 ("Btrfs: don't do nocow check unless we have to")
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>
|
|
[PROBLEM]
Before this patch, when btrfs_qgroup_reserve_data() fails, we free all
reserved space of the changeset.
For example:
ret = btrfs_qgroup_reserve_data(inode, changeset, 0, SZ_1M);
ret = btrfs_qgroup_reserve_data(inode, changeset, SZ_1M, SZ_1M);
ret = btrfs_qgroup_reserve_data(inode, changeset, SZ_2M, SZ_1M);
If the last btrfs_qgroup_reserve_data() failed, it will release the
entire [0, 3M) range.
This behavior is kind of OK for now, as when we hit -EDQUOT, we normally
go error handling and need to release all reserved ranges anyway.
But this also means the following call is not possible:
ret = btrfs_qgroup_reserve_data();
if (ret == -EDQUOT) {
/* Do something to free some qgroup space */
ret = btrfs_qgroup_reserve_data();
}
As if the first btrfs_qgroup_reserve_data() fails, it will free all
reserved qgroup space.
[CAUSE]
This is because we release all reserved ranges when
btrfs_qgroup_reserve_data() fails.
[FIX]
This patch will implement a new function, qgroup_unreserve_range(), to
iterate through the ulist nodes, to find any nodes in the failure range,
and remove the EXTENT_QGROUP_RESERVED bits from the io_tree, and
decrease the extent_changeset::bytes_changed, so that we can revert to
previous state.
This allows later patches to retry btrfs_qgroup_reserve_data() if EDQUOT
happens.
Suggested-by: Josef Bacik <josef@toxicpanda.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>
|
|
This patch will add the following sysfs interface:
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/referenced
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/exclusive
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/max_referenced
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/max_exclusive
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/limit_flags
Which is also available in output of "btrfs qgroup show".
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/rsv_data
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/rsv_meta_pertrans
/sys/fs/btrfs/<UUID>/qgroups/<qgroup_id>/rsv_meta_prealloc
The last 3 rsv related members are not visible to users, but can be very
useful to debug qgroup limit related bugs.
Also, to avoid '/' used in <qgroup_id>, the separator between qgroup
level and qgroup id is changed to '_'.
The interface is not hidden behind 'debug' as we want this interface to
be included into production build and to provide another way to read the
qgroup information besides the ioctls.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The qgroup level is limited to u16, so no need to use u64 for it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
vfs_inode is used only for the inode number everything else requires
btrfs_inode.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use btrfs_ino ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There's only a single use of vfs_inode in a tracepoint so let's take
btrfs_inode directly.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
It just forwards its argument to __btrfs_qgroup_release_data.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
It passes btrfs_inode to its callee so change the interface.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
It uses vfs_inode only for a tracepoint so convert its interface to take
btrfs_inode directly.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
It only uses btrfs_inode so can just as easily take it as an argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Before this patch, qgroup completely relies on per-inode extent io tree
to detect reserved data space leak.
However previous bug has already shown how release page before
btrfs_finish_ordered_io() could lead to leak, and since it's
QGROUP_RESERVED bit cleared without triggering qgroup rsv, it can't be
detected by per-inode extent io tree.
So this patch adds another (and hopefully the final) safety net to catch
qgroup data reserved space leak. At least the new safety net catches
all the leaks during development, so it should be pretty useful in the
real world.
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>
|
|
qgroup
[BUG]
For the following operation, qgroup is guaranteed to be screwed up due
to snapshot adding to a new qgroup:
# mkfs.btrfs -f $dev
# mount $dev $mnt
# btrfs qgroup en $mnt
# btrfs subv create $mnt/src
# xfs_io -f -c "pwrite 0 1m" $mnt/src/file
# sync
# btrfs qgroup create 1/0 $mnt/src
# btrfs subv snapshot -i 1/0 $mnt/src $mnt/snapshot
# btrfs qgroup show -prce $mnt/src
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16.00KiB 16.00KiB none none --- ---
0/257 1.02MiB 16.00KiB none none --- ---
0/258 1.02MiB 16.00KiB none none 1/0 ---
1/0 0.00B 0.00B none none --- 0/258
^^^^^^^^^^^^^^^^^^^^
[CAUSE]
The problem is in btrfs_qgroup_inherit(), we don't have good enough
check to determine if the new relation would break the existing
accounting.
Unlike btrfs_add_qgroup_relation(), which has proper check to determine
if we can do quick update without a rescan, in btrfs_qgroup_inherit() we
can even assign a snapshot to multiple qgroups.
[FIX]
Fix it by manually marking qgroup inconsistent for snapshot inheritance.
For subvolume creation, since all its extents are exclusively owned, we
don't need to rescan.
In theory, we should call relation check like quick_update_accounting()
when doing qgroup inheritance and inform user about qgroup accounting
inconsistency.
But we don't have good mechanism to relay that back to the user in the
snapshot creation context, thus we can only silently mark the qgroup
inconsistent.
Anyway, user shouldn't use qgroup inheritance during snapshot creation,
and should add qgroup relationship after snapshot creation by 'btrfs
qgroup assign', which has a much better UI to inform user about qgroup
inconsistent and kick in rescan automatically.
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>
|
|
There are a few different ways to free roots, either you allocated them
yourself and you just do
free_extent_buffer(root->node);
free_extent_buffer(root->commit_node);
btrfs_put_root(root);
Which is the pattern for log roots. Or for snapshots/subvolumes that
are being dropped you simply call btrfs_free_fs_root() which does all
the cleanup for you.
Unify this all into btrfs_put_root(), so that we don't free up things
associated with the root until the last reference is dropped. This
makes the root freeing code much more significant.
The only caveat is at close_ctree() time we have to free the extent
buffers for all of our main roots (extent_root, chunk_root, etc) because
we have to drop the btree_inode and we'll run into issues if we hold
onto those nodes until ->kill_sb() time. This will be addressed in the
future when we kill the btree_inode.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
After the previous patch, qgroup_rescan_running is protected by
btrfs_fs_info::qgroup_rescan_lock, thus no need for the extra spinlock.
Suggested-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>
|
|
at least queued
[BUG]
There are some reports about btrfs wait forever to unmount itself, with
the following call trace:
INFO: task umount:4631 blocked for more than 491 seconds.
Tainted: G X 5.3.8-2-default #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
umount D 0 4631 3337 0x00000000
Call Trace:
([<00000000174adf7a>] __schedule+0x342/0x748)
[<00000000174ae3ca>] schedule+0x4a/0xd8
[<00000000174b1f08>] schedule_timeout+0x218/0x420
[<00000000174af10c>] wait_for_common+0x104/0x1d8
[<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs]
[<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs]
[<0000000016fa3136>] generic_shutdown_super+0x8e/0x158
[<0000000016fa34d6>] kill_anon_super+0x26/0x40
[<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs]
[<0000000016fa39f8>] deactivate_locked_super+0x68/0x98
[<0000000016fcb198>] cleanup_mnt+0xc0/0x140
[<0000000016d6a846>] task_work_run+0xc6/0x110
[<0000000016d04f76>] do_notify_resume+0xae/0xb8
[<00000000174b30ae>] system_call+0xe2/0x2c8
[CAUSE]
The problem happens when we have called qgroup_rescan_init(), but
not queued the worker. It can be caused mostly by error handling.
Qgroup ioctl thread | Unmount thread
----------------------------------------+-----------------------------------
|
btrfs_qgroup_rescan() |
|- qgroup_rescan_init() |
| |- qgroup_rescan_running = true; |
| |
|- trans = btrfs_join_transaction() |
| Some error happened |
| |
|- btrfs_qgroup_rescan() returns error |
But qgroup_rescan_running == true; |
| close_ctree()
| |- btrfs_qgroup_wait_for_completion()
| |- running == true;
| |- wait_for_completion();
btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake
up close_ctree() and we get a deadlock.
All involved qgroup_rescan_init() callers are:
- btrfs_qgroup_rescan()
The example above. It's possible to trigger the deadlock when error
happened.
- btrfs_quota_enable()
Not possible. Just after qgroup_rescan_init() we queue the work.
- btrfs_read_qgroup_config()
It's possible to trigger the deadlock. It only init the work, the
work queueing happens in btrfs_qgroup_rescan_resume().
Thus if error happened in between, deadlock is possible.
We shouldn't set fs_info->qgroup_rescan_running just in
qgroup_rescan_init(), as at that stage we haven't yet queued qgroup
rescan worker to run.
[FIX]
Set qgroup_rescan_running before queueing the work, so that we ensure
the rescan work is queued when we wait for it.
Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization")
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Change subject and cause analyse, use a smaller fix ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We are now using these for all roots, rename them to btrfs_put_root()
and btrfs_grab_root();
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>
|
|
If we are going to track leaked roots we need to free them all the same
way, so don't kfree() roots directly, use btrfs_put_fs_root.
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>
|
|
We clean up the delayed references when we abort a transaction but we
leave the pending qgroup extent records behind, leaking memory.
This patch destroys the extent records when we destroy the delayed refs
and makes sure ensure they're gone before releasing the transaction.
Fixes: 3368d001ba5d ("btrfs: qgroup: Record possible quota-related extent for qgroup.")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Rebased to latest upstream, remove to_qgroup() helper, use
rbtree_postorder_for_each_entry_safe() wrapper ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
[PROBLEM]
qgroup create/remove code is currently returning EINVAL when the user
tries to create a qgroup on a subvolume without quota enabled. EINVAL is
already being used for too many error scenarios so that is hard to
depict what is the problem.
[FIX]
Currently scrub and balance code return -ENOTCONN when the user tries to
cancel/pause and no scrub or balance is currently running for the
desired subvolume. Do the same here by returning -ENOTCONN when a user
tries to create/delete/assing/list a qgroup on a subvolume without quota
enabled.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|