Ed Cashin fb32975d1b aoe: adjust ref of head for compound page tails ... Fix a BUG which can trigger when direct-IO is used with AOE. As discussed previously, the fact that some users of the block layer provide bios that point to pages with a zero _count means that it is not OK for the network layer to do a put_page on the skb frags during an skb_linearize, so the aoe driver gets a reference to pages in bios and puts the reference before ending the bio. And because it cannot use get_page on a page with a zero _count, it manipulates the value directly. It is not OK to increment the _count of a compound page tail, though, since the VM layer will VM_BUG_ON a non-zero _count. Block users that do direct I/O can result in the aoe driver seeing compound page tails in bios. In that case, the same logic works as long as the head of the compound page is used instead of the tails. This patch handles compound pages and does not BUG. It relies on the block layer user leaving the relationship between the page tail and its head alone for the duration between the submission of the bio and its completion, whether successful or not. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2013-08-13 17:57:48 -07:00
..
aoe.h	aoe: update internal version number to v83	2013-07-03 16:08:05 -07:00
aoeblk.c	block_device_operations->release() should return void	2013-05-07 02:16:21 -04:00
aoechr.c	aoe: replace kmalloc and then memcpy with kmemdup	2013-04-30 17:04:08 -07:00
aoecmd.c	aoe: adjust ref of head for compound page tails	2013-08-13 17:57:48 -07:00
aoedev.c	aoe: update copyright date	2013-07-03 16:08:05 -07:00
aoemain.c	aoe: whitespace cleanup	2012-12-17 17:15:24 -08:00
aoenet.c	aoe: update copyright date	2013-07-03 16:08:05 -07:00
Makefile	drivers/block/aoe/Makefile: replace the use of <module>-objs with <module>-y	2011-01-19 08:25:02 -07:00