[XFS] write barrier support Issue all log sync operations as ordered

writes.  In addition flush the disk cache on fsync if the sync cached
operation didn't sync the log to disk (this requires some additional
bookeping in the transaction and log code). If the device doesn't claim to
support barriers, the filesystem has an extern log volume or the trial
superblock write with barriers enabled failed we disable barriers and
print a warning.  We should probably fail the mount completely, but that
could lead to nasty boot failures for the root filesystem.  Not enabled by
default yet, needs more destructive testing first.

SGI-PV: 912426
SGI-Modid: xfs-linux:xfs-kern:198723a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 5affba38a577..bc55931ac74e 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -415,7 +415,7 @@ typedef struct xfs_mount {
                                                  * 32 bits in size */
 #define XFS_MOUNT_32BITINOOPT   0x00008000      /* saved mount option state */
 #define XFS_MOUNT_NOUUID        0x00010000      /* ignore uuid during mount */
-#define XFS_MOUNT_NOLOGFLUSH    0x00020000
+#define XFS_MOUNT_BARRIER       0x00020000
 #define XFS_MOUNT_IDELETE       0x00040000      /* delete empty inode clusters*/
 #define XFS_MOUNT_SWALLOC       0x00080000      /* turn on stripe width
                                                  * allocation */
@@ -542,6 +542,7 @@ extern xfs_mount_t *xfs_mount_init(void);
 extern void     xfs_mod_sb(xfs_trans_t *, __int64_t);
 extern void     xfs_mount_free(xfs_mount_t *mp, int remove_bhv);
 extern int      xfs_mountfs(struct vfs *, xfs_mount_t *mp, int);
+extern void     xfs_mountfs_check_barriers(xfs_mount_t *mp);
 
 extern int      xfs_unmountfs(xfs_mount_t *, struct cred *);
 extern void     xfs_unmountfs_close(xfs_mount_t *, struct cred *);