6 files changed, 29 insertions, 2 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 943381284e2e..1b60e46f527f 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -314,6 +314,7 @@ xfs_parseargs(
                         args->flags |= XFSMNT_ATTR2;
                 } else if (!strcmp(this_char, MNTOPT_NOATTR2)) {
                         args->flags &= ~XFSMNT_ATTR2;
+                        args->flags |= XFSMNT_NOATTR2;
                 } else if (!strcmp(this_char, MNTOPT_FILESTREAM)) {
                         args->flags2 |= XFSMNT2_FILESTREAMS;
                 } else if (!strcmp(this_char, MNTOPT_NOQUOTA)) {
diff --git a/fs/xfs/xfs_clnt.h b/fs/xfs/xfs_clnt.h
index d5d1e60ee224..d2ce5dd70d87 100644
--- a/fs/xfs/xfs_clnt.h
+++ b/fs/xfs/xfs_clnt.h
@@ -78,6 +78,7 @@ struct xfs_mount_args {
 #define XFSMNT_IOSIZE           0x00002000      /* optimize for I/O size */
 #define XFSMNT_OSYNCISOSYNC     0x00004000      /* o_sync is REALLY o_sync */
                                                 /* (osyncisdsync is default) */
+#define XFSMNT_NOATTR2          0x00008000      /* turn off ATTR2 EA format */
 #define XFSMNT_32BITINODES      0x00200000      /* restrict inodes to 32
                                                  * bits of address space */
 #define XFSMNT_GQUOTA           0x00400000      /* group quota accounting */
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index da3988453b71..361c7a755a07 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -994,9 +994,19 @@ xfs_mountfs(
                  * Re-check for ATTR2 in case it was found in bad_features2
                  * slot.
                  */
-                if (xfs_sb_version_hasattr2(&mp->m_sb))
+                if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+                   !(mp->m_flags & XFS_MOUNT_NOATTR2))
                         mp->m_flags |= XFS_MOUNT_ATTR2;
+        }
+
+        if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+           (mp->m_flags & XFS_MOUNT_NOATTR2)) {
+                xfs_sb_version_removeattr2(&mp->m_sb);
+                update_flags |= XFS_SB_FEATURES2;
 
+                /* update sb_versionnum for the clearing of the morebits */
+                if (!sbp->sb_features2)
+                        update_flags |= XFS_SB_VERSIONNUM;
         }
 
         /*
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 63e0693a358a..4aff0c125ad3 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -378,6 +378,7 @@ typedef struct xfs_mount {
                                                    counters */
 #define XFS_MOUNT_FILESTREAMS   (1ULL << 24)    /* enable the filestreams
                                                    allocator */
+#define XFS_MOUNT_NOATTR2       (1ULL << 25)    /* disable use of attr2 format */
 
 
 /*
diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h
index d904efe7f871..e3204a36a222 100644
--- a/fs/xfs/xfs_sb.h
+++ b/fs/xfs/xfs_sb.h
@@ -473,6 +473,13 @@ static inline void xfs_sb_version_addattr2(xfs_sb_t *sbp)
                 ((sbp)->sb_features2 | XFS_SB_VERSION2_ATTR2BIT)));
 }
 
+static inline void xfs_sb_version_removeattr2(xfs_sb_t *sbp)
+{
+        sbp->sb_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
+        if (!sbp->sb_features2)
+                sbp->sb_versionnum &= ~XFS_SB_VERSION_MOREBITSBIT;
+}
+
 /*
  * end of superblock version macros
  */
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index 30bacd8bb0e5..bbc911720d81 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -284,6 +284,8 @@ xfs_start_flags(
                 mp->m_flags |= XFS_MOUNT_DIRSYNC;
         if (ap->flags & XFSMNT_ATTR2)
                 mp->m_flags |= XFS_MOUNT_ATTR2;
+        if (ap->flags & XFSMNT_NOATTR2)
+                mp->m_flags |= XFS_MOUNT_NOATTR2;
 
         if (ap->flags2 & XFSMNT2_COMPAT_IOSIZE)
                 mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
@@ -346,7 +348,12 @@ xfs_finish_flags(
                 }
         }
 
-        if (xfs_sb_version_hasattr2(&mp->m_sb))
+        /*
+         * mkfs'ed attr2 will turn on attr2 mount unless explicitly
+         * told by noattr2 to turn it off
+         */
+        if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+            !(ap->flags & XFSMNT_NOATTR2))
                 mp->m_flags |= XFS_MOUNT_ATTR2;
 
         /*