torvalds-linux/Documentation/filesystems
Andrey Vagin 49d063cb35 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>
2014-04-07 16:36:04 -07:00
..
caching
cifs
configfs
nfs
pohmelfs
9p.txt
00-INDEX
adfs.txt
affs.txt
afs.txt
autofs4-mount-control.txt
automount-support.txt
befs.txt
bfs.txt
btrfs.txt
ceph.txt
coda.txt
cramfs.txt
debugfs.txt
devpts.txt
directory-locking
dlmfs.txt
dnotify_test.c
dnotify.txt
ecryptfs.txt
efivarfs.txt
exofs.txt
ext2.txt
ext3.txt
ext4.txt
f2fs.txt
fiemap.txt
files.txt
fuse.txt
gfs2-glocks.txt
gfs2-uevents.txt
gfs2.txt
hfs.txt
hfsplus.txt
hpfs.txt
inotify.txt
isofs.txt
jfs.txt
Locking mm: introduce vm_ops->map_pages() 2014-04-07 16:35:52 -07:00
locks.txt
logfs.txt
Makefile
mandatory-locking.txt
ncpfs.txt
nilfs2.txt
ntfs.txt Documentation/filesystems/ntfs.txt: remove changelog reference 2014-04-03 16:21:27 -07:00
ocfs2.txt
omfs.txt
path-lookup.txt
porting
proc.txt proc: show mnt_id in /proc/pid/fdinfo 2014-04-07 16:36:04 -07:00
qnx6.txt
quota.txt
ramfs-rootfs-initramfs.txt
relay.txt
romfs.txt
seq_file.txt
sharedsubtree.txt
spufs.txt
squashfs.txt
sysfs-pci.txt
sysfs-tagging.txt
sysfs.txt
sysv-fs.txt
tmpfs.txt
ubifs.txt
udf.txt
ufs.txt
vfat.txt
vfs.txt
xfs-delayed-logging-design.txt
xfs-self-describing-metadata.txt
xfs.txt
xip.txt