[PATCH V3] xfs: do not log/recover swapext extent owner changes for deleted inodes

[Eric Sandeen <sandeen@sandeen.net>]

Today if we run xfs_fsr and crash[1], log replay can fail because
the recovery code tries to instantiate the donor inode from
disk to replay the swapext, but it's been deleted and we get
verifier failures when we try to read the inode off disk with
i_mode == 0.

This fixes both sides: We don't log the swapext change if the
inode has been deleted, and we don't try to recover it either.

[1] or if systemd doesn't uncleanly unmount root, as is its wont
    to do ...

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

V2: Move the fix to xfs_ifree per bfoster's suggestion
V3: Fix my eeeediot logic thinko, and add back in replay fix
    so that people already in this situation can recover.
    Tidy up commit log a bit.

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 604ee38..d17e2d5 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2470,6 +2470,10 @@
 	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
 	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
+
+	/* Don't attempt to replay owner changes for a deleted inode */
+	ip->i_itemp->ili_fields &= ~(XFS_ILOG_AOWNER|XFS_ILOG_DOWNER);
+
 	/*
 	 * Bump the generation count so no one will be confused
 	 * by reincarnations of this inode.
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 5e219d9..d0e33b9 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -3199,7 +3199,9 @@ xlog_recover_inode_pass2(
 	}
 
 out_owner_change:
-	if (in_f->ilf_fields & (XFS_ILOG_DOWNER|XFS_ILOG_AOWNER))
+	/* Recover the swapext owner change unless inode has been deleted */
+	if ((in_f->ilf_fields & (XFS_ILOG_DOWNER|XFS_ILOG_AOWNER)) &&
+	    (dip->di_mode != 0))
 		error = xfs_recover_inode_owner_change(mp, dip, in_f,
 						       buffer_list);
 	/* re-generate the checksum. */