[RESEND v3 PATCH] vfs: show_vfsstat: do not ignore errors from show_devname method

From: Dmitry V. Levin
Date: Thu Feb 18 2016 - 20:56:52 EST


Date: Thu, 19 Mar 2015 11:10:54 +0000

Explicitly check show_devname method return code and bail out in case
of an error. This fixes regression introduced by commit 9d4d65748a5c.

Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
---
fs/proc_namespace.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 2256e7e..3f1190d 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -190,26 +190,28 @@ out:
static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
{
struct proc_mounts *p = m->private;
struct mount *r = real_mount(mnt);
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
struct super_block *sb = mnt_path.dentry->d_sb;
int err;

/* device */
if (sb->s_op->show_devname) {
seq_puts(m, "device ");
err = sb->s_op->show_devname(m, mnt_path.dentry);
+ if (err)
+ goto out;
} else {
if (r->mnt_devname) {
seq_puts(m, "device ");
mangle(m, r->mnt_devname);
} else
seq_puts(m, "no device");
}

/* mount point */
seq_puts(m, " mounted on ");
/* mountpoints outside of chroot jail will give SEQ_SKIP on this */
err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
if (err)
goto out;
--
ldv