From 93f1c20bc8cdb757be50566eff88d65c3b26881f Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Sat, 29 Jan 2011 18:43:38 +0530 Subject: [PATCH] vfs: Export file system uuid via /proc//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 Signed-off-by: Al Viro --- 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; -- 2.30.2