linux/drivers/block
Ilya Dryomov 9638556a27 rbd: handle parent_overlap on writes correctly
The following check in rbd_img_obj_request_submit()

    rbd_dev->parent_overlap <= obj_request->img_offset

allows the fall through to the non-layered write case even if both
parent_overlap and obj_request->img_offset belong to the same RADOS
object.  This leads to data corruption, because the area to the left of
parent_overlap ends up unconditionally zero-filled instead of being
populated with parent data.  Suppose we want to write 1M to offset 6M
of image bar, which is a clone of foo@snap; object_size is 4M,
parent_overlap is 5M:

    rbd_data.<id>.0000000000000001
     ---------------------|----------------------|------------
    | should be copyup'ed | should be zeroed out | write ...
     ---------------------|----------------------|------------
   4M                    5M                     6M
                    parent_overlap    obj_request->img_offset

4..5M should be copyup'ed from foo, yet it is zero-filled, just like
5..6M is.

Given that the only striping mode kernel client currently supports is
chunking (i.e. stripe_unit == object_size, stripe_count == 1), round
parent_overlap up to the next object boundary for the purposes of the
overlap check.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-06-23 12:55:37 +04:00
..
aoe
drbd
mtip32xx mtip32xx: minor performance enhancements 2014-06-06 13:28:48 -06:00
paride
rsxx
xen-blkback xen-blkback: defer freeing blkif to avoid blocking xenwatch 2014-05-28 14:17:32 -04:00
zram zram: correct offset usage in zram_bio_discard 2014-06-04 16:54:13 -07:00
amiflop.c
ataflop.c Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next 2014-06-02 09:29:34 -07:00
brd.c brd: return -ENOSPC rather than -ENOMEM on page allocation failure 2014-06-04 16:54:02 -07:00
cciss_cmd.h
cciss_scsi.c
cciss_scsi.h
cciss.c
cciss.h
cpqarray.c
cpqarray.h
cryptoloop.c
DAC960.c
DAC960.h
floppy.c Merge branch 'for-3.16/drivers' of git://git.kernel.dk/linux-block into next 2014-06-02 13:57:01 -07:00
hd.c
ida_cmd.h
ida_ioctl.h
Kconfig
loop.c
loop.h
Makefile
mg_disk.c
nbd.c nbd: zero from and len fields in NBD_CMD_DISCONNECT. 2014-06-06 16:08:18 -07:00
null_blk.c null_blk: fix softirq completions for queue_mode == 1 2014-06-16 11:40:25 -06:00
nvme-core.c Merge git://git.infradead.org/users/willy/linux-nvme 2014-06-15 15:58:03 -10:00
nvme-scsi.c NVMe: Fix START_STOP_UNIT Scsi->NVMe translation. 2014-06-13 13:11:00 -04:00
osdblk.c
pktcdvd.c block: add blk_rq_set_block_pc() 2014-06-06 07:57:37 -06:00
ps3disk.c
ps3vram.c
rbd_types.h
rbd.c rbd: handle parent_overlap on writes correctly 2014-06-23 12:55:37 +04:00
skd_main.c
skd_s1120.h
smart1,2.h
sunvdc.c
swim3.c
swim_asm.S
swim.c
sx8.c
umem.c
umem.h
virtio_blk.c Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next 2014-06-02 09:29:34 -07:00
xen-blkfront.c Merge branch 'stable/for-jens-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into for-3.16/drivers 2014-05-28 12:37:04 -06:00
xsysace.c
z2ram.c