Revert "vfs: Export file system uuid via /proc/<pid>/mountinfo"

This reverts commit 93f1c20bc8cdb757be50566eff88d65c3b26881f.

It turns out that libmount misparses it because it adds a '-' character
in the uuid string, which libmount then incorrectly confuses with the
separator string (" - ") at the end of all the optional arguments.

Upstream libmount (in the util-linux tree) has been fixed, but until
that fix actually percolates up to users, we'd better not expose this
change in the kernel.

Let's revisit this later (possibly by exposing the UUID without any '-'
characters in it, avoiding the user-space bug).

Reported-by: Dave Jones <davej@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Karel Zak <kzak@redhat.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/namespace.c b/fs/namespace.c
index 7dba2ed03429460f27aba058955208ed5dd929ec..d99bcf59e4c2fd23b2c03d2c9ed7471f7b2b230e 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1030,18 +1030,6 @@ const struct seq_operations mounts_op = {
        .show   = show_vfsmnt
 };
 
-static int uuid_is_nil(u8 *uuid)
-{
-       int i;
-       u8  *cp = (u8 *)uuid;
-
-       for (i = 0; i < 16; i++) {
-               if (*cp++)
-                       return 0;
-       }
-       return 1;
-}
-
 static int show_mountinfo(struct seq_file *m, void *v)
 {
        struct proc_mounts *p = m->private;
@@ -1085,10 +1073,6 @@ static int show_mountinfo(struct seq_file *m, void *v)
        if (IS_MNT_UNBINDABLE(mnt))
                seq_puts(m, " unbindable");
 
-       if (!uuid_is_nil(mnt->mnt_sb->s_uuid))
-               /* print the uuid */
-               seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid);
-
        /* Filesystem specific data */
        seq_puts(m, " - ");
        show_type(m, sb);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index dbd860af08041bbaa5e333104aaa3ab0849cb676..5b14843af9f9fe52d8c1059981fb4e1bfb736dbc 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1403,7 +1403,6 @@ struct super_block {
        wait_queue_head_t       s_wait_unfrozen;
 
        char s_id[32];                          /* Informational name */
-       u8 s_uuid[16];                          /* UUID */
 
        void                    *s_fs_info;     /* Filesystem private info */
        fmode_t                 s_mode;