linux-stable/drivers/block
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 aoe: adjust ref of head for compound page tails 2013-08-13 17:57:48 -07:00
drbd drbd: Allow online change of al-stripes and al-stripe-size 2013-06-28 16:04:36 +02:00
mtip32xx drivers: avoid parsing names as kthread_run() format strings 2013-07-03 16:07:41 -07:00
paride block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00
rsxx rsxx: Adding in debugfs entries. 2013-06-19 13:52:10 +02:00
xen-blkback Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block 2013-07-22 19:02:52 -07:00
amiflop.c block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00
ataflop.c block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00
brd.c drivers/block/brd.c: fix brd_lookup_page() race 2013-05-24 16:22:52 -07:00
cciss.c cciss: fix broken mutex usage in ioctl 2013-06-12 16:29:45 -07:00
cciss.h
cciss_cmd.h
cciss_scsi.c cciss: switch to ->show_info() 2013-04-09 14:13:19 -04:00
cciss_scsi.h
cpqarray.c block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00
cpqarray.h
cryptoloop.c move linux/loop.h to drivers/block 2013-06-29 12:46:45 +04:00
DAC960.c procfs: new helper - PDE_DATA(inode) 2013-04-09 14:13:32 -04:00
DAC960.h
floppy.c Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block 2013-05-08 10:13:35 -07:00
hd.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
ida_cmd.h
ida_ioctl.h
Kconfig rsxx: Changing the adapter name to the official name. 2013-06-19 13:52:09 +02:00
loop.c move linux/loop.h to drivers/block 2013-06-29 12:46:45 +04:00
loop.h move linux/loop.h to drivers/block 2013-06-29 12:46:45 +04:00
Makefile NVMe: Add nvme-scsi.c 2013-03-28 14:50:49 -04:00
mg_disk.c Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block 2013-05-08 11:51:05 -07:00
nbd.c nbd: correct disconnect behavior 2013-07-03 16:08:05 -07:00
nvme-core.c NVMe: Add MSI support 2013-05-31 11:45:52 -04:00
nvme-scsi.c NVMe: Fix a signedness bug in nvme_trans_modesel_get_mp 2013-05-17 09:10:38 -04:00
osdblk.c block: Add bio_clone_bioset(), bio_clone_kmalloc() 2012-09-09 10:35:39 +02:00
pktcdvd.c pktcdvd: silence static checker warning 2013-05-29 15:36:22 +02:00
ps3disk.c Drivers: block: remove __dev* attributes. 2013-01-03 15:57:15 -08:00
ps3vram.c procfs: new helper - PDE_DATA(inode) 2013-04-09 14:13:32 -04:00
rbd.c rbd: fix a couple warnings 2013-07-03 15:32:50 -07:00
rbd_types.h rbd: get rid of RBD_MAX_SEG_NAME_LEN 2012-12-17 08:37:29 -06:00
smart1,2.h
sunvdc.c sunvdc: Fix off-by-one in generic_request(). 2013-02-14 11:49:01 -08:00
swim.c swim: Release memory region after incorrect return/goto 2013-06-24 19:44:19 +02:00
swim3.c block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00
swim_asm.S
sx8.c block, sx8: fix pointer math issue getting fw version 2012-03-03 19:44:39 +01:00
umem.c Drivers: block: remove __dev* attributes. 2013-01-03 15:57:15 -08:00
umem.h
virtio_blk.c virtio_blk: Add missing 'static' qualifiers 2013-05-20 12:09:23 +09:30
xen-blkfront.c Merge branch 'stable/for-jens-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-3.11/drivers 2013-06-28 16:01:14 +02:00
xsysace.c xilinx systemace: Fix sparse warnings 2013-07-10 07:47:12 +02:00
z2ram.c block_device_operations->release() should return void 2013-05-07 02:16:21 -04:00