Re: [PATCH] Support for unsupported options.

[Hans Reiser <reiser@namesys.com>]

Approved.  flx, please confirm that this addresses the objection you had 
to acls in SuSE distros preventing use of vanilla kernels.

Hans

Jeff Mahoney wrote:

>
> Yes, the subject sounds silly, but it's needed.
>
> The set of allowable mount options shouldn't change based on the running
> kernel configuration. The feature that the option corresponds to may be
> unavailable, but it should be sufficient to warn the user that the the
> feature is disabled, but the mount has succeeded.
>
> Ext3 does this for things like acl/xattr, and I feel that we should as 
> well.
>
> Fortunately, the code to implement it is trivial.
>
> Attached are two patches.
> * reiserfs-unsupported-opts.diff
> ~  - Adds a REISERFS_UNSUPPORTED_OPT mount flag, and uses it to denote
> ~    when a mount option is allowed, but not supported in the running
> ~    configuration.
> ~  - Rather than setting/clearing this bit, it's treated as special
> ~    and issues a warning using the name of the mount option.
> * reiserfs-unsupported-acl.diff
> ~  - Uses the above flag to denote ACLs and user xattrs as unsupported
> ~    when support is not compiled in.
>
> Currently, if a filesystem is mounted with -oacl and they are not
> compiled in, the filesystem will fail to mount.
>
> Hans - Please take a quick look, I'd like to get this one upstream ASAP.
>
> -Jeff
>
> --
> Jeff Mahoney
> SuSE Labs


 >-------------------------

 >This patch uses the REISERFS_UNSUPPORTED_OPT flag to denote -o(no)acl, and
 >-o(no)user_xattr as unsupported, but allowable, when support isn't 
built into
 >the kernel.

 >Signed-off-by: Jeff Mahoney <jeffm@novell.com>

 >diff -ruPX dontdiff linux-2.6.8/fs/reiserfs/super.c 
linux-2.6.8.fix/fs/reiserfs/super.c
 >--- linux-2.6.8/fs/reiserfs/super.c    2004-10-08 16:46:09.070660248 -0400
 >+++ linux-2.6.8.fix/fs/reiserfs/super.c    2004-10-08 
16:42:59.896419104 -0400
 >@@ -741,11 +747,19 @@
    {"conv",    .setmask = 1<<REISERFS_CONVERT},
    {"attrs",    .setmask = 1<<REISERFS_ATTRS},
    {"noattrs",    .clrmask = 1<<REISERFS_ATTRS},
 >+#ifdef CONFIG_REISERFS_FS_XATTR
    {"user_xattr",    .setmask = 1<<REISERFS_XATTRS_USER},
    {"nouser_xattr",.clrmask = 1<<REISERFS_XATTRS_USER},
 >+#else
 >+    {"user_xattr",    .setmask = 1<<REISERFS_UNSUPPORTED_OPT},
 >+    {"nouser_xattr",.clrmask = 1<<REISERFS_UNSUPPORTED_OPT},
 >+#endif
#ifdef CONFIG_REISERFS_FS_POSIX_ACL
    {"acl",        .setmask = 1<<REISERFS_POSIXACL},
    {"noacl",    .clrmask = 1<<REISERFS_POSIXACL},
 >+#else
 >+    {"acl",        .setmask = 1<<REISERFS_UNSUPPORTED_OPT},
 >+    {"noacl",    .clrmask = 1<<REISERFS_UNSUPPORTED_OPT},
#endif
    {"nolog",},     /* This is unsupported */
    {"replayonly",    .setmask = 1<<REPLAYONLY},


 >-------------------------

 >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>

 >diff -ruPX dontdiff linux-2.6.8/fs/reiserfs/super.c 
linux-2.6.8.fix/fs/reiserfs/super.c
 >--- linux-2.6.8/fs/reiserfs/super.c    2004-10-08 16:46:09.070660248 -0400
 >+++ linux-2.6.8.fix/fs/reiserfs/super.c    2004-10-08 
16:42:59.896419104 -0400
 >@@ -659,8 +659,14 @@
    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;
    }
 >diff -ruPX dontdiff linux-2.6.8/include/linux/reiserfs_fs_sb.h 
linux-2.6.8.fix/include/linux/reiserfs_fs_sb.h
 >--- linux-2.6.8/include/linux/reiserfs_fs_sb.h    2004-10-08 
16:46:04.541348808 -0400
 >+++ linux-2.6.8.fix/include/linux/reiserfs_fs_sb.h    2004-10-08 
16:31:50.641161368 -0400
 >@@ -467,6 +467,7 @@
    REISERFS_TEST2,
    REISERFS_TEST3,
    REISERFS_TEST4,
 >+    REISERFS_UNSUPPORTED_OPT,
};

#define reiserfs_r5_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << 
FORCE_R5_HASH))