From 93f1c20bc8cdb757be50566eff88d65c3b26881f Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Date: Sat, 29 Jan 2011 18:43:38 +0530
Subject: [PATCH] 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>
---
fs/namespace.c | 16 ++++++++++++++++
include/linux/fs.h | 1 +
2 files changed, 17 insertions(+)
diff --git a/fs/namespace.c b/fs/namespace.c
index d1edf26025dc..dffe6f49ab93 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1002,6 +1002,18 @@ 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;
@@ -1040,6 +1052,10 @@ 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 3f64630c0e10..f2143e0942c2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1408,6 +1408,7 @@ 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;