Adrian Hunter f281fb5fe5 block: prevent merges of discard and write requests ... Add logic to prevent two I/O requests being merged if only one of them is a discard. Ditto secure discard. Without this fix, it is possible for write requests to transform into discard requests. For example: Submit bio 1 to discard 8 sectors from sector n Submit bio 2 to write 8 sectors from sector n + 16 Submit bio 3 to write 8 sectors from sector n + 8 Bio 1 becomes request 1. Bio 2 becomes request 2. Bio 3 is merged with request 2, and then subsequently request 2 is merged with request 1 resulting in just one I/O request which discards all 24 sectors. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> (Moved the checks above the position checks /Jens) Signed-off-by: Jens Axboe <jaxboe@fusionio.com>		2010-09-25 12:42:55 +02:00
..
blk-barrier.c
blk-cgroup.c
blk-cgroup.h
blk-core.c
blk-exec.c
blk-integrity.c
blk-ioc.c
blk-iopoll.c
blk-lib.c
blk-map.c
blk-merge.c
blk-settings.c
blk-softirq.c
blk-sysfs.c
blk-tag.c
blk-timeout.c
blk.h
bsg.c
cfq-iosched.c
cfq.h
compat_ioctl.c
deadline-iosched.c
elevator.c
genhd.c
ioctl.c
Kconfig
Kconfig.iosched
Makefile
noop-iosched.c
scsi_ioctl.c