From: Qu Wenruo <wqu@xxxxxxxx> commit ea0eba69a2a8125229b1b6011644598039bc53aa upstream. There is a user report about "btrfs filesystem defrag" causing 120s timeout problem. For btrfs_defrag_file() it will iterate all file extents if called from defrag ioctl, thus it can take a long time. There is no reason not to release the CPU during such a long operation. Add cond_resched() after defragged one cluster. CC: stable@xxxxxxxxxxxxxxx # 5.16 Link: https://lore.kernel.org/linux-btrfs/10e51417-2203-f0a4-2021-86c8511cc367@xxxxxxx Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/ioctl.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1603,6 +1603,7 @@ int btrfs_defrag_file(struct inode *inod ret = 0; break; } + cond_resched(); } if (ra_allocated) Patches currently in stable-queue which might be from wqu@xxxxxxxx are queue-5.16/btrfs-don-t-hold-cpu-for-too-long-when-defragging-a-file.patch queue-5.16/btrfs-defrag-don-t-try-to-defrag-extents-which-are-under-writeback.patch
