xfs: don't leave EFIs on AIL on mount failure

Log recovery occurs in two phases at mount time. In the first phase,
EFIs and EFDs are processed and potentially cancelled out. EFIs without
EFD objects are inserted into the AIL for processing and recovery in the
second phase. xfs_mountfs() runs various other operations between the
phases and is thus subject to failure. If failure occurs after the first
phase but before the second, pending EFIs sit on the AIL, pin it and
cause the mount to hang.

Update the mount sequence to ensure that pending EFIs are cancelled in
the event of failure. Add a recovery cancellation mechanism to iterate
the AIL and cancel all EFI items when requested. Plumb cancellation
support through the log mount finish helper and update xfs_mountfs() to
invoke cancellation in the event of failure after recovery has started.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 461e791efad7..4825a8a0a506 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -615,14 +615,14 @@ xfs_default_resblks(xfs_mount_t *mp)
  */
 int
 xfs_mountfs(
-	xfs_mount_t	*mp)
+	struct xfs_mount	*mp)
 {
-	xfs_sb_t	*sbp = &(mp->m_sb);
-	xfs_inode_t	*rip;
-	__uint64_t	resblks;
-	uint		quotamount = 0;
-	uint		quotaflags = 0;
-	int		error = 0;
+	struct xfs_sb		*sbp = &(mp->m_sb);
+	struct xfs_inode	*rip;
+	__uint64_t		resblks;
+	uint			quotamount = 0;
+	uint			quotaflags = 0;
+	int			error = 0;
 
 	xfs_sb_mount_common(mp, sbp);
 
@@ -799,7 +799,9 @@ xfs_mountfs(
 	}
 
 	/*
-	 * log's mount-time initialization. Perform 1st part recovery if needed
+	 * Log's mount-time initialization. The first part of recovery can place
+	 * some items on the AIL, to be handled when recovery is finished or
+	 * cancelled.
 	 */
 	error = xfs_log_mount(mp, mp->m_logdev_targp,
 			      XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
@@ -910,9 +912,9 @@ xfs_mountfs(
 	}
 
 	/*
-	 * Finish recovering the file system.  This part needed to be
-	 * delayed until after the root and real-time bitmap inodes
-	 * were consistently read in.
+	 * Finish recovering the file system.  This part needed to be delayed
+	 * until after the root and real-time bitmap inodes were consistently
+	 * read in.
 	 */
 	error = xfs_log_mount_finish(mp);
 	if (error) {
@@ -956,7 +958,7 @@ xfs_mountfs(
  out_rele_rip:
 	IRELE(rip);
  out_log_dealloc:
-	xfs_log_unmount(mp);
+	xfs_log_mount_cancel(mp);
  out_fail_wait:
 	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
 		xfs_wait_buftarg(mp->m_logdev_targp);