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  1. 18 Nov, 2008 8 commits
  3. 17 Nov, 2008 12 commits
  5. 16 Nov, 2008 16 commits
  7. 15 Nov, 2008 4 commits
    • Ron Madrid's avatar
      phy: Add support for Marvell 88E1118 PHY · 605f196e
      Ron Madrid authored 
      This patch will add support for the Marvell 88E1118 PHY which supports gigabit ethernet among other things.
Signed-off-by: default avatarRon Madrid <ron_madrid@sbcglobal.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      605f196e
    • Yevgeny Petrilin's avatar
      mlx4_en: Pause parameters per port · d53b93f2
      Yevgeny Petrilin authored 
      Before the change the driver reported the same pause parameters
for all the ports, even only one of them was modified.
Signed-off-by: default avatarYevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d53b93f2
    • Linus Torvalds's avatar
      Linux 2.6.28-rc5 · 9bf1a244
      Linus Torvalds authored
      9bf1a244
    • Al Viro's avatar
      Fix inotify watch removal/umount races · 8f7b0ba1
      Al Viro authored 
      Inotify watch removals suck violently.

To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex.  That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount.  We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.

Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done.  Cleanup is just deactivate_super().

However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords.  That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.

We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable.  OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e.  that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().

So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong.  We had
to drop ih->mutex before we could grab ->s_umount.  So the watch
could've been gone already.

That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer.  If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address.  That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that.  Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.

So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check.  If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.

And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Acked-by: default avatarGreg KH <greg@kroah.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8f7b0ba1
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