On Wed, Feb 16, 2022 at 03:09:07PM +0800, Qu Wenruo wrote: > commit 2d192fc4c1abeb0d04d1c8cd54405ff4a0b0255b upstream. This commit is already in 5.15.22. > > 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 # 5.15 > 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> > --- > fs/btrfs/ioctl.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 6a863b3f6de0..38a1b68c7851 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -1581,6 +1581,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, > last_len = 0; > } > } > + cond_resched(); > } > > ret = defrag_count; > -- > 2.35.1 > The original commit looks nothing like this commit at all. Are you sure you got this correct? confused, greg k-h
