xfs: avoid false quotacheck after unclean shutdown

commit 5ef828c4 upstream.

The commit

83e782e1 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@excellency.fr>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Arkadiusz Miśkiewicz <arekm@maven.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/xfs/xfs_mount.c

@@ -321,7 +321,6 @@ xfs_readsb(
 	 * Initialize the mount structure from the superblock.
 	 */
 	xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(bp));
-	xfs_sb_quota_from_disk(sbp);
 
 	/*
 	 * If we haven't validated the superblock, do so now before we try

fs/xfs/xfs_sb.c

@@ -397,10 +397,11 @@ 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);
@@ -456,6 +457,17 @@ 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
@@ -571,7 +583,11 @@ 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