Mike Snitzer e9637415a9 block: fix blk_stack_limits() regression due to lcm() change ... Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n") caused blk_stack_limits() to not properly stack queue_limits for stacked devices (e.g. DM). Fix this regression by establishing lcm_not_zero() and switching blk_stack_limits() over to using it. DM uses blk_set_stacking_limits() to establish the initial top-level queue_limits that are then built up based on underlying devices' limits using blk_stack_limits(). In the case of optimal_io_size (io_opt) blk_set_stacking_limits() establishes a default value of 0. With commit 69c953c, lcm(0, n) is no longer n, which compromises proper stacking of the underlying devices' io_opt. Test: $ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536 $ cat /sys/block/sde/queue/optimal_io_size 786432 $ dmsetup create node --table "0 100 linear /dev/sde 0" Before this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 0 After this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 786432 Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.19+ Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>		2015-03-31 09:45:50 -06:00
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partitions
bio-integrity.c
bio.c
blk-cgroup.c
blk-cgroup.h
blk-core.c
blk-exec.c
blk-flush.c
blk-integrity.c
blk-ioc.c
blk-iopoll.c
blk-lib.c
blk-map.c
blk-merge.c
blk-mq-cpu.c
blk-mq-cpumap.c
blk-mq-sysfs.c
blk-mq-tag.c
blk-mq-tag.h
blk-mq.c
blk-mq.h
blk-settings.c
blk-softirq.c
blk-sysfs.c
blk-tag.c
blk-throttle.c
blk-timeout.c
blk.h
bounce.c
bsg-lib.c
bsg.c
cfq-iosched.c
cmdline-parser.c
compat_ioctl.c
deadline-iosched.c
elevator.c
genhd.c
ioctl.c
ioprio.c
Kconfig
Kconfig.iosched
Makefile
noop-iosched.c
partition-generic.c
scsi_ioctl.c
t10-pi.c