tree 06232f6fc975bd279236fd8005c7d5528220ec68
parent df4edad1787bbfa3c9c10824e4f11e9f4a7ec5c6
author James Bottomley <James.Bottomley@HansenPartnership.com> 1126051011 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> 1126142814 -0700

[PATCH] fix klist semantics for lists which have elements removed on traversal

The problem is that klists claim to provide semantics for safe traversal of
lists which are being modified.  The failure case is when traversal of a
list causes element removal (a fairly common case).  The issue is that
although the list node is refcounted, if it is embedded in an object (which
is universally the case), then the object will be freed regardless of the
klist refcount leading to slab corruption because the klist iterator refers
to the prior element to get the next.

The solution is to make the klist take and release references to the
embedding object meaning that the embedding object won't be released until
the list relinquishes the reference to it.

(akpm: fast-track this because it's needed for the 2.6.13 scsi merge)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>