forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

take the targets of /proc/*/ns/* symlinks to separate fs

Browse source 
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-11-01 10:57:28 -04:00
commit e149ed2b80
10 changed files with 208 additions and 161 deletions
Download patch file Download diff file Expand all files Collapse all files

2
init/main.c
View file

@ -78,6 +78,7 @@
#include <linux/context_tracking.h>
#include <linux/random.h>
#include <linux/list.h>
#include <linux/proc_ns.h>
#include <asm/io.h>
#include <asm/bugs.h>
@ -660,6 +661,7 @@ asmlinkage __visible void __init start_kernel(void)
/* rootfs populating might need page-writeback */
page_writeback_init();
proc_root_init();
nsfs_init();
cgroup_init();
cpuset_init();
taskstats_init_early();