linux/block
Tejun Heo fd63836811 block: an exiting task should be allowed to create io_context
While fixing io_context creation / task exit race condition,
6e736be7f2 "block: make ioc get/put interface more conventional and
fix race on alloction" also prevented an exiting (%PF_EXITING) task
from creating its own io_context.  This is incorrect as exit path may
issue IOs, e.g. from exit_files(), and if those IOs are the first ones
issued by the task, io_context needs to be created to process the IOs.

Combined with the existing problem of io_context / io_cq creation
failure having the possibility of stalling IO, this problem results in
deterministic full IO lockup with certain workloads.

Fix it by allowing io_context creation regardless of %PF_EXITING for
%current.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-12-25 14:29:14 +01:00
..
blk-cgroup.c block, cfq: unlink cfq_io_context's immediately 2011-12-14 00:33:39 +01:00
blk-cgroup.h block: fix a typo in the blk-cgroup.h file 2011-10-24 16:08:38 +02:00
blk-core.c block, cfq: move icq creation and rq->elv.icq association to block core 2011-12-14 00:33:42 +01:00
blk-exec.c block: add missing blk_queue_dead() checks 2011-12-14 00:33:37 +01:00
blk-flush.c blk-flush: move the queue kick into 2011-10-24 16:24:31 +02:00
blk-integrity.c block: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros 2011-10-31 19:31:12 -04:00
blk-ioc.c block: an exiting task should be allowed to create io_context 2011-12-25 14:29:14 +01:00
blk-iopoll.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
blk-lib.c block: fix patch import error in max_discard_sectors check 2011-07-23 20:34:59 +02:00
blk-map.c block: Always check length of all iov entries in blk_rq_map_user_iov() 2011-11-13 19:58:09 +01:00
blk-merge.c block: attempt to merge with existing requests on plug flush 2011-03-21 10:14:27 +01:00
blk-settings.c block: Fix discard topology stacking and reporting 2011-05-18 10:37:35 +02:00
blk-softirq.c block: Don't check QUEUE_FLAG_SAME_COMP in __blk_complete_request 2011-09-14 09:31:01 +02:00
blk-sysfs.c block, cfq: move io_cq exit/release to blk-ioc.c 2011-12-14 00:33:42 +01:00
blk-tag.c block: warn if tag is greater than real_max_depth. 2011-10-25 10:20:05 +02:00
blk-throttle.c block: add blk_queue_dead() 2011-12-14 00:33:37 +01:00
blk-timeout.c fault-injection: add ability to export fault_attr in arbitrary directory 2011-08-03 14:25:20 -10:00
blk.h block, cfq: move icq creation and rq->elv.icq association to block core 2011-12-14 00:33:42 +01:00
bsg-lib.c block: Change module.h -> export.h in bsg-lib.c 2011-10-31 19:31:13 -04:00
bsg.c block: misc updates to blk_get_queue() 2011-12-14 00:33:38 +01:00
cfq-iosched.c block, cfq: fix empty queue crash caused by request merge 2011-12-16 14:00:22 +01:00
cfq.h blk-cgroup: Add unaccounted time to timeslice_used. 2011-03-12 16:54:00 +01:00
compat_ioctl.c compat_ioctl: fix warning caused by qemu 2011-07-01 22:32:26 +02:00
deadline-iosched.c block, cfq: move icq cache management to block core 2011-12-14 00:33:42 +01:00
elevator.c block: recursive merge requests 2011-12-16 14:00:31 +01:00
genhd.c block: misc updates to blk_get_queue() 2011-12-14 00:33:38 +01:00
ioctl.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
Kconfig block: add bsg helper library 2011-07-31 22:05:09 +02:00
Kconfig.iosched blk-cgroup: config options re-arrangement 2010-04-26 19:27:56 +02:00
Makefile block: add bsg helper library 2011-07-31 22:05:09 +02:00
noop-iosched.c block, cfq: move icq cache management to block core 2011-12-14 00:33:42 +01:00
scsi_ioctl.c block: drop unnecessary blk_get/put_queue() in scsi_cmd_ioctl() and blk_get_tg() 2011-10-19 14:31:25 +02:00