vfs: Export file system uuid via /proc/<pid>/mountinfo
We add a per superblock uuid field. File systems should
update the uuid in the fill_super callback
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index d1edf26..dffe6f4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1002,6 +1002,18 @@
.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;
@@ -1040,6 +1052,10 @@
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);