linux-toradex.git/fs/namespace.c, branch v3.7

vfs: define struct filename and have getname() return it

2012-10-13T00:14:55+00:00

getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.

Signed-off-by: Jeff Layton 
Signed-off-by: Al Viro

consitify do_mount() arguments

2012-10-12T00:02:04+00:00

Signed-off-by: Al Viro

do_add_mount()/umount -l races

2012-09-23T00:48:18+00:00

normally we deal with lock_mount()/umount races by checking that
mountpoint to be is still in our namespace after lock_mount() has
been done.  However, do_add_mount() skips that check when called
with MNT_SHRINKABLE in flags (i.e. from finish_automount()).  The
reason is that ->mnt_ns may be a temporary namespace created exactly
to contain automounts a-la NFS4 referral handling.  It's not the
namespace of the caller, though, so check_mnt() would fail here.
We still need to check that ->mnt_ns is non-NULL in that case,
though.

Signed-off-by: Al Viro

fs: Add freezing handling to mnt_want_write() / mnt_drop_write()

2012-07-31T05:40:38+00:00

Most of places where we want freeze protection coincides with the places where
we also have remount-ro protection. So make mnt_want_write() and
mnt_drop_write() (and their _file alternative) prevent freezing as well.
For the few cases that are really interested only in remount-ro protection
provide new function variants.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa 
Tested-by: Peter M. Petrakis 
Tested-by: Dann Frazier 
Tested-by: Massimo Morana 
Signed-off-by: Jan Kara 
Signed-off-by: Al Viro

VFS: Comment mount following code

2012-07-14T12:38:32+00:00

Add comments describing what the directions "up" and "down" mean and ref count
handling to the VFS mount following family of functions.

Signed-off-by: Valerie Aurora  (Original author)
Signed-off-by: David Howells 
Signed-off-by: Al Viro

VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors

2012-07-14T12:37:27+00:00

copy_tree() can theoretically fail in a case other than ENOMEM, but always
returns NULL which is interpreted by callers as -ENOMEM.  Change it to return
an explicit error.

Also change clone_mnt() for consistency and because union mounts will add new
error cases.

Thanks to Andreas Gruenbacher  for a bug fix.
[AV: folded braino fix by Dan Carpenter]

Original-author: Valerie Aurora 
Signed-off-by: David Howells 
Cc: Valerie Aurora 
Cc: Andreas Gruenbacher 
Signed-off-by: Al Viro

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: umount_tree() might be called on subtree that had never made it

2012-05-31T01:04:55+00:00

__mnt_make_shortterm() in there undoes the effect of __mnt_make_longterm()
we'd done back when we set ->mnt_ns non-NULL; it should not be done to
vfsmounts that had never gone through commit_tree() and friends.  Kudos to
lczerner for catching that one...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro

brlocks/lglocks: API cleanups

2012-05-30T03:28:41+00:00

lglocks and brlocks are currently generated with some complicated macros
in lglock.h.  But there's no reason to not just use common utility
functions and put all the data into a common data structure.

In preparation, this patch changes the API to look more like normal
function calls with pointers, not magic macros.

The patch is rather large because I move over all users in one go to keep
it bisectable.  This impacts the VFS somewhat in terms of lines changed.
But no actual behaviour change.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen 
Cc: Al Viro 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Rusty Russell 
Signed-off-by: Al Viro