linux.git/fs/mount.h, branch v3.10

get rid of full-hash scan on detaching vfsmounts

2013-04-09T18:12:52+00:00

Signed-off-by: Al Viro

proc: Usable inode numbers for the namespace file descriptors.

2012-11-20T12:19:49+00:00

Assign a unique proc inode to each namespace, and use that
inode number to ensure we only allocate at most one proc
inode for every namespace in proc.

A single proc inode per namespace allows userspace to test
to see if two processes are in the same namespace.

This has been a long requested feature and only blocked because
a naive implementation would put the id in a global space and
would ultimately require having a namespace for the names of
namespaces, making migration and certain virtualization tricks
impossible.

We still don't have per superblock inode numbers for proc, which
appears necessary for application unaware checkpoint/restart and
migrations (if the application is using namespace file descriptors)
but that is now allowd by the design if it becomes important.

I have preallocated the ipc and uts initial proc inode numbers so
their structures can be statically initialized.

Signed-off-by: Eric W. Biederman

vfs: Add a user namespace reference from struct mnt_namespace

2012-11-19T13:59:19+00:00

This will allow for support for unprivileged mounts in a new user namespace.

Acked-by: "Serge E. Hallyn" 
Signed-off-by: "Eric W. Biederman"

vfs: Add setns support for the mount namespace

2012-11-19T13:59:18+00:00

setns support for the mount namespace is a little tricky as an
arbitrary decision must be made about what to set fs->root and
fs->pwd to, as there is no expectation of a relationship between
the two mount namespaces.  Therefore I arbitrarily find the root
mount point, and follow every mount on top of it to find the top
of the mount stack.  Then I set fs->root and fs->pwd to that
location.  The topmost root of the mount stack seems like a
reasonable place to be.

Bind mount support for the mount namespace inodes has the
possibility of creating circular dependencies between mount
namespaces.  Circular dependencies can result in loops that
prevent mount namespaces from every being freed.  I avoid
creating those circular dependencies by adding a sequence number
to the mount namespace and require all bind mounts be of a
younger mount namespace into an older mount namespace.

Add a helper function proc_ns_inode so it is possible to
detect when we are attempting to bind mound a namespace inode.

Acked-by: Serge Hallyn 
Signed-off-by: Eric W. Biederman

get rid of magic in proc_namespace.c

2012-07-14T12:32:48+00:00

don't rely on proc_mounts->m being the first field; container_of()
is there for purpose.  No need to bother with ->private, while
we are at it - the same container_of will do nicely.

Signed-off-by: Al Viro

get rid of ->mnt_longterm

2012-07-14T12:32:47+00:00

it's enough to set ->mnt_ns of internal vfsmounts to something
distinct from all struct mnt_namespace out there; then we can
just use the check for ->mnt_ns != NULL in the fast path of
mntput_no_expire()

Signed-off-by: Al Viro

vfs: keep list of mounts for each superblock

2012-01-07T04:20:12+00:00

Keep track of vfsmounts belonging to a superblock.  List is protected
by vfsmount_lock.

Signed-off-by: Miklos Szeredi 
Tested-by: Toshiyuki Okajima 
Signed-off-by: Al Viro

switch mnt_namespace ->root to struct mount

2012-01-04T03:57:13+00:00

Signed-off-by: Al Viro

vfs: take /proc/*/mounts and friends to fs/proc_namespace.c

2012-01-04T03:57:13+00:00

rationale: that stuff is far tighter bound to fs/namespace.c than to
the guts of procfs proper.

Signed-off-by: Al Viro

vfs: move fsnotify junk to struct mount

2012-01-04T03:57:12+00:00

Signed-off-by: Al Viro