[PATCH 087/102] xfs: flush outstanding buffers on log mount failure

[Dave Chinner]

From: Dave Chinner <dchinner at redhat.com>

Upstream commit: d4f3512b0891658b6b4d5fc99567242b3fc2d6b7

When we fail to mount the log in xfs_mountfs(), we tear down all the
infrastructure we have already allocated. However, the process of
mounting the log may have progressed to the point of reading,
caching and modifying buffers in memory. Hence before we can free
all the infrastructure, we have to flush and remove all the buffers
from memory.

Problem first reported by Eric Sandeen, later a different incarnation
was reported by Ben Myers.

Signed-off-by: Dave Chinner <dchinner at redhat.com>
Reviewed-by: Mark Tinguely <tinguely at sgi.com>
Reviewed-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Ben Myers <bpm at sgi.com>
---
 fs/xfs/xfs_mount.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 2f011fd..beb9968 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1297,7 +1297,7 @@ xfs_mountfs(
 			      XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
 	if (error) {
 		xfs_warn(mp, "log mount failed");
-		goto out_free_perag;
+		goto out_fail_wait;
 	}
 
 	/*
@@ -1324,7 +1324,7 @@ xfs_mountfs(
 	     !mp->m_sb.sb_inprogress) {
 		error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
 		if (error)
-			goto out_free_perag;
+			goto out_fail_wait;
 	}
 
 	/*
@@ -1448,6 +1448,10 @@ xfs_mountfs(
 	IRELE(rip);
  out_log_dealloc:
 	xfs_log_unmount(mp);
+ out_fail_wait:
+	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
+		xfs_wait_buftarg(mp->m_logdev_targp);
+	xfs_wait_buftarg(mp->m_ddev_targp);
  out_free_perag:
 	xfs_free_perag(mp);
  out_remove_uuid:
-- 
1.7.10