Subject: [merged] proc-show-mnt_id-in-proc-pid-fdinfo.patch removed from -mm tree
To: avagin@xxxxxxxxxx,ebiederm@xxxxxxxxxxxx,gorcunov@xxxxxxxxxx,oleg@xxxxxxxxxx,rob@xxxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx,xemul@xxxxxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 08 Apr 2014 14:16:48 -0700
The patch titled
Subject: proc: show mnt_id in /proc/pid/fdinfo
has been removed from the -mm tree. Its filename was
proc-show-mnt_id-in-proc-pid-fdinfo.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Andrey Vagin <avagin@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx>
Acked-by: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Acked-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Rob Landley <rob@xxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 17 ++++++++++++-----
fs/proc/fd.c | 6 ++++--
2 files changed, 16 insertions(+), 7 deletions(-)
diff -puN Documentation/filesystems/proc.txt~proc-show-mnt_id-in-proc-pid-fdinfo Documentation/filesystems/proc.txt
--- a/Documentation/filesystems/proc.txt~proc-show-mnt_id-in-proc-pid-fdinfo
+++ a/Documentation/filesystems/proc.txt
@@ -1648,18 +1648,21 @@ pids, so one need to either stop or free
if precise results are needed.
-3.7 /proc/<pid>/fdinfo/<fd> - Information about opened file
+3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
---------------------------------------------------------------
This file provides information associated with an opened file. The regular
-files have at least two fields -- 'pos' and 'flags'. The 'pos' represents
-the current offset of the opened file in decimal form [see lseek(2) for
-details] and 'flags' denotes the octal O_xxx mask the file has been
-created with [see open(2) for details].
+files have at least three fields -- 'pos', 'flags' and mnt_id. The 'pos'
+represents the current offset of the opened file in decimal form [see lseek(2)
+for details], 'flags' denotes the octal O_xxx mask the file has been
+created with [see open(2) for details] and 'mnt_id' represents mount ID of
+the file system containing the opened file [see 3.5 /proc/<pid>/mountinfo
+for details].
A typical output is
pos: 0
flags: 0100002
+ mnt_id: 19
The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
pair provide additional information particular to the objects they represent.
@@ -1668,6 +1671,7 @@ pair provide additional information part
~~~~~~~~~~~~~
pos: 0
flags: 04002
+ mnt_id: 9
eventfd-count: 5a
where 'eventfd-count' is hex value of a counter.
@@ -1676,6 +1680,7 @@ pair provide additional information part
~~~~~~~~~~~~~~
pos: 0
flags: 04002
+ mnt_id: 9
sigmask: 0000000000000200
where 'sigmask' is hex value of the signal mask associated
@@ -1685,6 +1690,7 @@ pair provide additional information part
~~~~~~~~~~~
pos: 0
flags: 02
+ mnt_id: 9
tfd: 5 events: 1d data: ffffffffffffffff
where 'tfd' is a target file descriptor number in decimal form,
@@ -1718,6 +1724,7 @@ pair provide additional information part
pos: 0
flags: 02
+ mnt_id: 9
fanotify flags:10 event-flags:0
fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
diff -puN fs/proc/fd.c~proc-show-mnt_id-in-proc-pid-fdinfo fs/proc/fd.c
--- a/fs/proc/fd.c~proc-show-mnt_id-in-proc-pid-fdinfo
+++ a/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,
}
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);
_
Patches currently in -mm which might be from avagin@xxxxxxxxxx are
origin.patch
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