[XFS] enable write barriers by default

SGI-PV: 912426
SGI-Modid: xfs-linux-melb:xfs-kern:201981a

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

Author: Christoph Hellwig

fs/xfs/linux-2.6/xfs_super.c

@@ -306,20 +306,23 @@ xfs_mountfs_check_barriers(xfs_mount_t *mp)
 		xfs_fs_cmn_err(CE_NOTE, mp,
 		  "Disabling barriers, not supported with external log device");
 		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+		return;
 	}
 
 	if (mp->m_ddev_targp->pbr_bdev->bd_disk->queue->ordered ==
 					QUEUE_ORDERED_NONE) {
 		xfs_fs_cmn_err(CE_NOTE, mp,
 		  "Disabling barriers, not supported by the underlying device");
 		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+		return;
 	}
 
 	error = xfs_barrier_test(mp);
 	if (error) {
 		xfs_fs_cmn_err(CE_NOTE, mp,
 		  "Disabling barriers, trial barrier write failed");
 		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+		return;
 	}
 }
 

fs/xfs/xfs_vfsops.c

@@ -312,6 +312,8 @@ xfs_start_flags(
 		mp->m_flags |= XFS_MOUNT_NOUUID;
 	if (ap->flags & XFSMNT_BARRIER)
 		mp->m_flags |= XFS_MOUNT_BARRIER;
+	else
+		mp->m_flags &= ~XFS_MOUNT_BARRIER;
 
 	return 0;
 }
@@ -655,6 +657,11 @@ xfs_mntupdate(
 	else
 		mp->m_flags &= ~XFS_MOUNT_NOATIME;
 
+	if (args->flags & XFSMNT_BARRIER)
+		mp->m_flags |= XFS_MOUNT_BARRIER;
+	else
+		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+
 	if ((vfsp->vfs_flag & VFS_RDONLY) &&
 	    !(*flags & MS_RDONLY)) {
 		vfsp->vfs_flag &= ~VFS_RDONLY;
@@ -1634,6 +1641,7 @@ xfs_vget(
 #define MNTOPT_NORECOVERY   "norecovery"   /* don't run XFS recovery */
 #define MNTOPT_BARRIER	"barrier"	/* use writer barriers for log write and
 					 * unwritten extent conversion */
+#define MNTOPT_NOBARRIER "nobarrier"	/* .. disable */
 #define MNTOPT_OSYNCISOSYNC "osyncisosync" /* o_sync is REALLY o_sync */
 #define MNTOPT_64BITINODE   "inode64"	/* inodes can be allocated anywhere */
 #define MNTOPT_IKEEP	"ikeep"		/* do not free empty inode clusters */
@@ -1681,6 +1689,7 @@ xfs_parseargs(
 
 	args->flags2 |= XFSMNT2_COMPAT_IOSIZE;
 	args->flags |= XFSMNT_COMPAT_ATTR;
+	args->flags |= XFSMNT_BARRIER;
 
 #if 0	/* XXX: off by default, until some remaining issues ironed out */
 	args->flags |= XFSMNT_IDELETE; /* default to on */
@@ -1806,6 +1815,8 @@ xfs_parseargs(
 			args->flags |= XFSMNT_NOUUID;
 		} else if (!strcmp(this_char, MNTOPT_BARRIER)) {
 			args->flags |= XFSMNT_BARRIER;
+		} else if (!strcmp(this_char, MNTOPT_NOBARRIER)) {
+			args->flags &= ~XFSMNT_BARRIER;
 		} else if (!strcmp(this_char, MNTOPT_IKEEP)) {
 			args->flags &= ~XFSMNT_IDELETE;
 		} else if (!strcmp(this_char, MNTOPT_NOIKEEP)) {
@@ -1892,7 +1903,6 @@ xfs_showargs(
 		{ XFS_MOUNT_NOUUID,		"," MNTOPT_NOUUID },
 		{ XFS_MOUNT_NORECOVERY,		"," MNTOPT_NORECOVERY },
 		{ XFS_MOUNT_OSYNCISOSYNC,	"," MNTOPT_OSYNCISOSYNC },
-		{ XFS_MOUNT_BARRIER,		"," MNTOPT_BARRIER },
 		{ XFS_MOUNT_IDELETE,		"," MNTOPT_NOIKEEP },
 		{ 0, NULL }
 	};
@@ -1941,6 +1951,9 @@ xfs_showargs(
 	if (!(vfsp->vfs_flag & VFS_32BITINODES))
 		seq_printf(m, "," MNTOPT_64BITINODE);
 
+	if (!(vfsp->vfs_flag & XFS_MOUNT_BARRIER))
+		seq_printf(m, "," MNTOPT_NOBARRIER);
+
 	if (vfsp->vfs_flag & VFS_GRPID)
 		seq_printf(m, "," MNTOPT_GRPID);