[XFS] fix a freeze/thaw deadlock

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

fs/xfs/linux-2.6/xfs_ioctl.c

@@ -818,12 +818,14 @@ xfs_ioctl(
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 
+		if (inode->i_sb->s_frozen == SB_UNFROZEN)
 			freeze_bdev(inode->i_sb->s_bdev);
 		return 0;
 
 	case XFS_IOC_THAW:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
+		if (inode->i_sb->s_frozen != SB_UNFROZEN)
 			thaw_bdev(inode->i_sb->s_bdev, inode->i_sb);
 		return 0;
 

fs/xfs/linux-2.6/xfs_vfs.h

@@ -216,4 +216,8 @@ extern void bhv_insert_all_vfsops(struct vfs *);
 extern void bhv_remove_all_vfsops(struct vfs *, int);
 extern void bhv_remove_vfsops(struct vfs *, int);
 
+#define fs_frozen(vfsp)		((vfsp)->vfs_super->s_frozen)
+#define fs_check_frozen(vfsp, level) \
+	vfs_check_frozen(vfsp->vfs_super, level);
+
 #endif	/* __XFS_VFS_H__ */

fs/xfs/xfs_fsops.c

@@ -590,9 +590,6 @@ xfs_fs_goingdown(
 	xfs_mount_t	*mp,
 	__uint32_t	inflags)
 {
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
 	switch (inflags) {
 	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
 		struct vfs *vfsp = XFS_MTOVFS(mp);

fs/xfs/xfs_log.c

@@ -811,7 +811,7 @@ xfs_log_need_covered(xfs_mount_t *mp)
 	xlog_t		*log = mp->m_log;
 	vfs_t		*vfsp = XFS_MTOVFS(mp);
 
-	if (vfsp->vfs_super->s_frozen || XFS_FORCED_SHUTDOWN(mp) ||
+	if (fs_frozen(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
 	    (vfsp->vfs_flag & VFS_RDONLY))
 		return 0;
 

fs/xfs/xfs_trans.c

@@ -131,7 +131,7 @@ xfs_trans_alloc(
 	xfs_mount_t	*mp,
 	uint		type)
 {
-	vfs_check_frozen(XFS_MTOVFS(mp)->vfs_super, SB_FREEZE_TRANS);
+	fs_check_frozen(XFS_MTOVFS(mp), SB_FREEZE_TRANS);
 	atomic_inc(&mp->m_active_trans);
 
 	return (_xfs_trans_alloc(mp, type));