On Sat, Aug 12, 2017 at 09:42:04AM +1000, Dave Chinner wrote:
> On Fri, Aug 11, 2017 at 12:50:10PM -0700, Darrick J. Wong wrote:
> > When we introduced the bmap redo log items, we set MS_ACTIVE on the
> > mountpoint and XFS_IRECOVERY on the inode to prevent unlinked inodes
> > from being truncated prematurely during log recovery. This also had the
> > effect of putting linked inodes on the lru instead of evicting them.
> >
> > Unfortunately, we neglected to find all those unreferenced lru inodes
> > and evict them after finishing log recovery, which means that we leak
> > them if anything goes wrong in the rest of xfs_mountfs, because the lru
> > is only cleaned out on unmount.
> >
> > Therefore, evict unreferenced inodes in the lru list immediately
> > after clearing MS_ACTIVE.
> >
> > Fixes: 17c12bcd30 ("xfs: when replaying bmap operations, don't let unlinked inodes get reaped")
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > Cc: viro@xxxxxxxxxxxxxxxxxx
> > ---
> > v2: use the vfs evict_inodes instead of duplicating it
> > ---
> > fs/inode.c | 1 +
> > fs/internal.h | 1 -
> > fs/xfs/xfs_mount.c | 12 ++++++++++++
> > include/linux/fs.h | 1 +
> > 4 files changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/inode.c b/fs/inode.c
> > index 5037059..6a1626e 100644
> > --- a/fs/inode.c
> > +++ b/fs/inode.c
> > @@ -637,6 +637,7 @@ void evict_inodes(struct super_block *sb)
> >
> > dispose_list(&dispose);
> > }
> > +EXPORT_SYMBOL_GPL(evict_inodes);
> >
> > /**
> > * invalidate_inodes - attempt to free all inodes on a superblock
> > diff --git a/fs/internal.h b/fs/internal.h
> > index 9676fe1..fedfe94 100644
> > --- a/fs/internal.h
> > +++ b/fs/internal.h
> > @@ -132,7 +132,6 @@ static inline bool atime_needs_update_rcu(const struct path *path,
> > extern void inode_io_list_del(struct inode *inode);
> >
> > extern long get_nr_dirty_inodes(void);
> > -extern void evict_inodes(struct super_block *);
> > extern int invalidate_inodes(struct super_block *, bool);
> >
> > /*
> > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > index a46c9d7..351e2c3 100644
> > --- a/fs/xfs/xfs_mount.c
> > +++ b/fs/xfs/xfs_mount.c
> > @@ -956,10 +956,22 @@ xfs_mountfs(
> > * inodes. Turn it off immediately after xfs_log_mount_finish
> > * so that we don't leak the quota inodes if subsequent mount
> > * activities fail.
> > + *
> > + * We let all inodes involved in redo item processing end up on
> > + * the LRU instead of being evicted immediately so that if we do
> > + * something to an unlinked inode, the irele won't cause
> > + * premature truncation and freeing of the inode, which results
> > + * in log recovery failure. We have to evict the unreferenced
> > + * lru inodes after clearing MS_ACTIVE because we don't
> > + * otherwise clean up the lru if there's a subsequent failure in
> > + * xfs_mountfs, which leads to us leaking the inodes if nothing
> > + * else (e.g. quotacheck) references the inodes before the
> > + * mount failure occurs.
> > */
> > mp->m_super->s_flags |= MS_ACTIVE;
> > error = xfs_log_mount_finish(mp);
> > mp->m_super->s_flags &= ~MS_ACTIVE;
> > + evict_inodes(mp->m_super);
>
> Shouldn't all this MS_ACTIVE flag and inode eviction stuff be put
> inside xfs_log_mount_finish()? Seems to me like wrapping it aroudn
> the outside is the wrong place to be putting it...
Yeah, I suppose we ought to shove everything into xfs_log_mount_finish
instead of dumping it all here...
--D
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
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