Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
btrfs: interrupt long running operations if the current process is fr…
…eezing [BUG] There is a bug report that running fstrim will prevent the system from hibernation, result the following dmesg: PM: suspend entry (deep) Filesystems sync: 0.060 seconds Freezing user space processes Freezing user space processes failed after 20.007 seconds (1 tasks refusing to freeze, wq_busy=0): task:fstrim state:D stack:0 pid:15564 tgid:15564 ppid:1 flags:0x00004006 Call Trace: <TASK> __schedule+0x381/0x1540 schedule+0x24/0xb0 schedule_timeout+0x1ea/0x2a0 io_schedule_timeout+0x19/0x50 wait_for_completion_io+0x78/0x140 submit_bio_wait+0xaa/0xc0 blkdev_issue_discard+0x65/0xb0 btrfs_issue_discard+0xcf/0x160 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] btrfs_discard_extent+0x120/0x2a0 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] do_trimming+0xd4/0x220 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] trim_bitmaps+0x418/0x520 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] btrfs_trim_block_group+0xcb/0x130 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] btrfs_trim_fs+0x119/0x460 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] btrfs_ioctl_fitrim+0xfb/0x160 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] btrfs_ioctl+0x11cc/0x29f0 [btrfs 7ab35b9b86062a46f6ff578bb32d55ecf8e6bf82] __x64_sys_ioctl+0x92/0xd0 do_syscall_64+0x5b/0x80 entry_SYSCALL_64_after_hwframe+0x7c/0xe6 RIP: 0033:0x7f5f3b529f9b RSP: 002b:00007fff279ebc20 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fff279ebd60 RCX: 00007f5f3b529f9b RDX: 00007fff279ebc90 RSI: 00000000c0185879 RDI: 0000000000000003 RBP: 000055748718b2d0 R08: 00005574871899e8 R09: 00007fff279eb010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 000055748718ac40 R14: 000055748718b290 R15: 000055748718b290 </TASK> OOM killer enabled. Restarting tasks ... done. random: crng reseeded on system resumption PM: suspend exit PM: suspend entry (s2idle) Filesystems sync: 0.047 seconds [CAUSE] PM code is freezing all user space processes before entering hibernation/suspension, but if a user space process is trapping into the kernel for a long running operation, it will not be frozen since it's still inside kernel. Normally those long running operations check for fatal signals and exit early, but freezing user space processes is not done by signals but a different infrastructure. Unfortunately btrfs only checks fatal signals but not if the current task is being frozen. [FIX] Introduce a helper, btrfs_task_interrupted(), to check both fatal signals and freezing status, and apply to all long running operations, with dedicated error code: - reflink (-EINTR) - fstrim (-ERESTARTSYS) - relocation (-ECANCELD) - llseek (-EINTR) - defrag (-EAGAIN) - fiemap (-EINTR) Reported-by: Rolf Wentland <[email protected]> Link: https://bugzilla.suse.com/show_bug.cgi?id=1229737 Reviewed-by: Josef Bacik <[email protected]> Signed-off-by: Qu Wenruo <[email protected]>
- Loading branch information