[PATCH] reiserfs: support for REISERFS_UNSUPPORTED_OPT notation

This patch adds a REISERFS_UNSUPPORTED_OPT flag to denote when a mount
option is allowable, but is unsupported in the running configuration.  This
allows the potential for the set of mount options to be consistent,
regardless of what features the kernel is compiled with.

Rather than failing the mount, a warning is issued and the mount succeeds.
Signed-off-by: Jeff Mahoney <jeffm@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/reiserfs/super.c

@@ -662,8 +662,14 @@ static int reiserfs_getopt ( struct super_block * s, char ** cur, opt_desc_t * o
     for (opt = opts; opt->option_name; opt ++) {
 	if (!strncmp (p, opt->option_name, strlen (opt->option_name))) {
 	    if (bit_flags) {
-		*bit_flags &= ~opt->clrmask;
-		*bit_flags |= opt->setmask;
+                if (opt->clrmask == (1 << REISERFS_UNSUPPORTED_OPT))
+                    reiserfs_warning (s, "%s not supported.", p);
+                else
+                    *bit_flags &= ~opt->clrmask;
+                if (opt->setmask == (1 << REISERFS_UNSUPPORTED_OPT))
+                    reiserfs_warning (s, "%s not supported.", p);
+                else
+                    *bit_flags |= opt->setmask;
 	    }
 	    break;
 	}

include/linux/reiserfs_fs_sb.h

@@ -467,6 +467,7 @@ enum reiserfs_mount_options {
     REISERFS_TEST2,
     REISERFS_TEST3,
     REISERFS_TEST4,
+    REISERFS_UNSUPPORTED_OPT,
 };
 
 #define reiserfs_r5_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_R5_HASH))