omfs: Implement show_options

Implement the show_options superblock op for omfs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Note that the uid and gid should possibly be displayed relative to the
viewer's user namespace.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Bob Copeland <me@bobcopeland.com>
cc: linux-karma-devel@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index 8c9034ee7383a9b2c8f8edf6d6752322d62e79ef..ee14af9e26f28f16d91076cc8b62b87b306afb52 100644 (file)
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -13,6 +13,7 @@
 #include <linux/buffer_head.h>
 #include <linux/vmalloc.h>
 #include <linux/writeback.h>
+#include <linux/seq_file.h>
 #include <linux/crc-itu-t.h>
 #include "omfs.h"
 
@@ -290,12 +291,40 @@ static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
        return 0;
 }
 
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int omfs_show_options(struct seq_file *m, struct dentry *root)
+{
+       struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
+       umode_t cur_umask = current_umask();
+
+       if (!uid_eq(sbi->s_uid, current_uid()))
+               seq_printf(m, ",uid=%u",
+                          from_kuid_munged(&init_user_ns, sbi->s_uid));
+       if (!gid_eq(sbi->s_gid, current_gid()))
+               seq_printf(m, ",gid=%u",
+                          from_kgid_munged(&init_user_ns, sbi->s_gid));
+
+       if (sbi->s_dmask == sbi->s_fmask) {
+               if (sbi->s_fmask != cur_umask)
+                       seq_printf(m, ",umask=%o", sbi->s_fmask);
+       } else {
+               if (sbi->s_dmask != cur_umask)
+                       seq_printf(m, ",dmask=%o", sbi->s_dmask);
+               if (sbi->s_fmask != cur_umask)
+                       seq_printf(m, ",fmask=%o", sbi->s_fmask);
+       }
+
+       return 0;
+}
+
 static const struct super_operations omfs_sops = {
        .write_inode    = omfs_write_inode,
        .evict_inode    = omfs_evict_inode,
        .put_super      = omfs_put_super,
        .statfs         = omfs_statfs,
-       .show_options   = generic_show_options,
+       .show_options   = omfs_show_options,
 };
 
 /*
@@ -434,8 +463,6 @@ static int omfs_fill_super(struct super_block *sb, void *data, int silent)
        struct inode *root;
        int ret = -EINVAL;
 
-       save_mount_options(sb, (char *) data);
-
        sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
        if (!sbi)
                return -ENOMEM;