diff options
| author | Andrey Vagin <avagin@openvz.org> | 2014-04-08 00:38:34 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-08 01:36:04 +0200 |
| commit | 49d063cb353265c3af701bab215ac438ca7df36d (patch) | |
| tree | d69fa40233df60a711965a37c8bd68c1f86edd1f /fs/proc/fd.c | |
| parent | fs/proc/meminfo: meminfo_proc_show(): fix typo in comment (diff) | |
| download | linux-49d063cb353265c3af701bab215ac438ca7df36d.tar.xz linux-49d063cb353265c3af701bab215ac438ca7df36d.zip | |
proc: show mnt_id in /proc/pid/fdinfo
Currently we don't have a way how to determing from which mount point
file has been opened. This information is required for proper dumping
and restoring file descriptos due to presence of mount namespaces. It's
possible, that two file descriptors are opened using the same paths, but
one fd references mount point from one namespace while the other fd --
from other namespace.
$ ls -l /proc/1/fd/1
lrwx------ 1 root root 64 Mar 19 23:54 /proc/1/fd/1 -> /dev/null
$ cat /proc/1/fdinfo/1
pos: 0
flags: 0100002
mnt_id: 16
$ cat /proc/1/mountinfo | grep ^16
16 32 0:4 / /dev rw,nosuid shared:2 - devtmpfs devtmpfs rw,size=1013356k,nr_inodes=253339,mode=755
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Rob Landley <rob@landley.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | fs/proc/fd.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 985ea881b5bc..0788d093f5d8 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -11,6 +11,7 @@ #include <linux/proc_fs.h> +#include "../mount.h" #include "internal.h" #include "fd.h" @@ -48,8 +49,9 @@ static int seq_show(struct seq_file *m, void *v) } if (!ret) { - seq_printf(m, "pos:\t%lli\nflags:\t0%o\n", - (long long)file->f_pos, f_flags); + seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", + (long long)file->f_pos, f_flags, + real_mount(file->f_path.mnt)->mnt_id); if (file->f_op->show_fdinfo) ret = file->f_op->show_fdinfo(m, file); fput(file); |