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  1. 28 Jul, 2010 2 commits
  3. 15 May, 2010 1 commit
    • Al Viro's avatar
      Fix the regression created by "set S_DEAD on unlink()..." commit · d83c49f3
      Al Viro authored 
      
1) i_flags simply doesn't work for mount/unlink race prevention;
we may have many links to file and rm on one of those obviously
shouldn't prevent bind on top of another later on.  To fix it
right way we need to mark _dentry_ as unsuitable for mounting
upon; new flag (DCACHE_CANT_MOUNT) is protected by d_flags and
i_mutex on the inode in question.  Set it (with dont_mount(dentry))
in unlink/rmdir/etc., check (with cant_mount(dentry)) in places
in namespace.c that used to check for S_DEAD.  Setting S_DEAD
is still needed in places where we used to set it (for directories
getting killed), since we rely on it for readdir/rmdir race
prevention.

2) rename()/mount() protection has another bogosity - we unhash
the target before we'd checked that it's not a mountpoint.  Fixed.

3) ancient bogosity in pivot_root() - we locked i_mutex on the
right directory, but checked S_DEAD on the different (and wrong)
one.  Noticed and fixed.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      d83c49f3
  5. 11 Apr, 2010 6 commits
  7. 03 Mar, 2010 7 commits
  9. 16 Jan, 2010 4 commits
  11. 17 Dec, 2009 1 commit
    • Linus Torvalds's avatar
      Revert "fix mismerge with Trond's stuff (create_mnt_ns() export is gone now)" · a2770d86
      Linus Torvalds authored 
      This reverts commit e9496ff4

. Quoth Al:

 "it's dependent on a lot of other stuff not currently in mainline
  and badly broken with current fs/namespace.c.  Sorry, badly
  out-of-order cherry-pick from old queue.

  PS: there's a large pending series reworking the refcounting and
  lifetime rules for vfsmounts that will, among other things, allow to
  rip a subtree away _without_ dissolving connections in it, to be
  garbage-collected when all active references are gone.  It's
  considerably saner wrt "is the subtree busy" logics, but it's nowhere
  near being ready for merge at the moment; this changeset is one of the
  things becoming possible with that sucker, but it certainly shouldn't
  have been picked during this cycle.  My apologies..."
Noticed-by: default avatarEric Paris <eparis@redhat.com>
Requested-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a2770d86
  13. 16 Dec, 2009 1 commit
  15. 11 Oct, 2009 1 commit
  17. 24 Sep, 2009 1 commit
    • Vegard Nossum's avatar
      fs: fix overflow in sys_mount() for in-kernel calls · eca6f534
      Vegard Nossum authored 
      
sys_mount() reads/copies a whole page for its "type" parameter.  When
do_mount_root() passes a kernel address that points to an object which is
smaller than a whole page, copy_mount_options() will happily go past this
memory object, possibly dereferencing "wild" pointers that could be in any
state (hence the kmemcheck warning, which shows that parts of the next
page are not even allocated).

(The likelihood of something going wrong here is pretty low -- first of
all this only applies to kernel calls to sys_mount(), which are mostly
found in the boot code.  Secondly, I guess if the page was not mapped,
exact_copy_from_user() _would_ in fact handle it correctly because of its
access_ok(), etc.  checks.)

But it is much nicer to avoid the dubious reads altogether, by stopping as
soon as we find a NUL byte.  Is there a good reason why we can't do
something like this, using the already existing strndup_from_user()?

[akpm@linux-foundation.org: make copy_mount_string() static]
[AV: fix compat mount breakage, which involves undoing akpm's change above]
Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avataral <al@dizzy.pdmi.ras.ru>
      eca6f534
  19. 07 Aug, 2009 1 commit
  21. 08 Jul, 2009 1 commit
  23. 24 Jun, 2009 2 commits
  25. 23 Jun, 2009 2 commits
    • Trond Myklebust's avatar
      VFS: Add VFS helper functions for setting up private namespaces · cf8d2c11
      Trond Myklebust authored 
      
The purpose of this patch is to improve the remote mount path lookup
support for distributed filesystems such as the NFSv4 client.

When given a mount command of the form "mount server:/foo/bar /mnt", the
NFSv4 client is required to look up the filehandle for "server:/", and
then look up each component of the remote mount path "foo/bar" in order
to find the directory that is actually going to be mounted on /mnt.
Following that remote mount path may involve following symlinks,
crossing server-side mount points and even following referrals to
filesystem volumes on other servers.

Since the standard VFS path lookup code already supports walking paths
that contain all these features (using in-kernel automounts for
following referrals) we would like to be able to reuse that rather than
duplicate the full path traversal functionality in the NFSv4 client code.

This patch therefore defines a VFS helper function create_mnt_ns(), that
sets up a temporary filesystem namespace and attaches a root filesystem to
it. It exports the create_mnt_ns() and put_mnt_ns() function for use by
filesystem modules.
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cf8d2c11
    • Trond Myklebust's avatar
      VFS: Uninline the function put_mnt_ns() · 616511d0
      Trond Myklebust authored 
      
In order to allow modules to use it without having to export vfsmount_lock.
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      616511d0
  27. 11 Jun, 2009 10 commits