[Trusty][SRU][PATCH] xfs: avoid false quotacheck after unclean shutdown

[Seyeong Kim]

From: Eric Sandeen <sandeen at sandeen.net>

BugLink: http://bugs.launchpad.net/bugs/1461730

The commit

83e782e xfs: Remove incore use of XFS_OQUOTA_ENFD and XFS_OQUOTA_CHKD

added a new function xfs_sb_quota_from_disk() which swaps
on-disk XFS_OQUOTA_* flags for in-core XFS_GQUOTA_* and XFS_PQUOTA_*
flags after the superblock is read.

However, if log recovery is required, the superblock is read again,
and the modified in-core flags are re-read from disk, so we have
XFS_OQUOTA_* flags in memory again.  This causes the
XFS_QM_NEED_QUOTACHECK() test to be true, because the XFS_OQUOTA_CHKD
is still set, and not XFS_GQUOTA_CHKD or XFS_PQUOTA_CHKD.

Change xfs_sb_from_disk to call xfs_sb_quota_from disk and always
convert the disk flags to in-memory flags.

Add a lower-level function which can be called with "false" to
not convert the flags, so that the sb verifier can verify
exactly what was on disk, per Brian Foster's suggestion.

Reported-by: Cyril B. <cbay at excellency.fr>
Signed-off-by: Eric Sandeen <sandeen at redhat.com>

(backported from commit 5ef828c4152726f56751c78ea844f08d2b2a4fa3)
Signed-off-by: Seyeong Kim <seyeong.kim at canonical.com>

Conflicts:
	fs/xfs/libxfs/xfs_sb.c
	fs/xfs/xfs_mount.c
---
 fs/xfs/xfs_mount.c |  1 -
 fs/xfs/xfs_sb.c    | 26 ++++++++++++++++++++++----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 02df7b4..e853572 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -314,7 +314,6 @@ reread:
 	 * Initialize the mount structure from the superblock.
 	 */
 	xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
-	xfs_sb_quota_from_disk(&mp->m_sb);
 
 	/*
 	 * We must be able to do sector-sized and sector-aligned IO.
diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
index b7c9aea..6301f33 100644
--- a/fs/xfs/xfs_sb.c
+++ b/fs/xfs/xfs_sb.c
@@ -398,10 +398,13 @@ xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 	}
 }
 
-void
-xfs_sb_from_disk(
+
+
+static void
+__xfs_sb_from_disk(
 	struct xfs_sb	*to,
-	xfs_dsb_t	*from)
+	xfs_dsb_t	*from,
+	bool	convert_xquota)
 {
 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
@@ -457,6 +460,17 @@ xfs_sb_from_disk(
 	to->sb_pad = 0;
 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
+	/* Convert on-disk flags to in-memory flags? */
+	if (convert_xquota)
+		xfs_sb_quota_from_disk(to);
+}
+
+void
+xfs_sb_from_disk(
+	struct xfs_sb   *to,
+	xfs_dsb_t       *from)
+{
+	__xfs_sb_from_disk(to, from, true);
 }
 
 static inline void
@@ -572,7 +586,11 @@ xfs_sb_verify(
 	struct xfs_mount *mp = bp->b_target->bt_mount;
 	struct xfs_sb	sb;
 
-	xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp));
+	/*
+	* Use call variant which doesn't convert quota flags from disk
+	* format, because xfs_mount_validate_sb checks the on-disk flags.
+	*/
+	__xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
 
 	/*
 	 * Only check the in progress field for the primary superblock as
-- 
2.1.4