svn commit: r230250 - head/sys/ufs/ffs

[Kirk McKusick]

Author: mckusick
Date: Tue Jan 17 01:14:56 2012
New Revision: 230250
URL: http://svn.freebsd.org/changeset/base/230250

Log:
  There are several bugs/hangs when trying to take a snapshot on a UFS/FFS
  filesystem running with journaled soft updates. Until these problems
  have been tracked down, return ENOTSUPP when an attempt is made to
  take a snapshot on a filesystem running with journaled soft updates.
  
  MFC after: 2 weeks

Modified:
  head/sys/ufs/ffs/ffs_snapshot.c

Modified: head/sys/ufs/ffs/ffs_snapshot.c
==============================================================================
--- head/sys/ufs/ffs/ffs_snapshot.c	Tue Jan 17 01:08:01 2012	(r230249)
+++ head/sys/ufs/ffs/ffs_snapshot.c	Tue Jan 17 01:14:56 2012	(r230250)
@@ -225,10 +225,18 @@ ffs_snapshot(mp, snapfile)
 	ump = VFSTOUFS(mp);
 	fs = ump->um_fs;
 	sn = NULL;
+	/*
+	 * At the moment, journaled soft updates cannot support
+	 * taking snapshots.
+	 */
+	if (MOUNTEDSUJ(mp)) {
+		vfs_mount_error(mp, "%s: Snapshots are not yet supported when "
+		    "running with journaled soft updates", fs->fs_fsmnt);
+		return (EOPNOTSUPP);
+	}
 	MNT_ILOCK(mp);
 	flag = mp->mnt_flag;
 	MNT_IUNLOCK(mp);
-
 	/*
 	 * Need to serialize access to snapshot code per filesystem.
 	 */