linux/block
Ming Lei b04a5636a6 block: replace trylock with mutex_lock in blkdev_reread_part()
The only possible problem of using mutex_lock() instead of trylock
is about deadlock.

If there aren't any locks held before calling blkdev_reread_part(),
deadlock can't be caused by this conversion.

If there are locks held before calling blkdev_reread_part(),
and if these locks arn't required in open, close handler and I/O
path, deadlock shouldn't be caused too.

Both user space's ioctl(BLKRRPART) and md_setup_drive() from
init/do_mounts_md.c belongs to the 1st case, so the conversion is safe
for the two cases.

For loop, the previous patches in this pathset has fixed the ABBA lock
dependency, so the conversion is OK.

For nbd, tx_lock is held when calling the function:

	- both open and release won't hold the lock
	- when blkdev_reread_part() is run, I/O thread has been stopped
	already, so tx_lock won't be acquired in I/O path at that time.
	- so the conversion won't cause deadlock for nbd

For dasd, both dasd_open(), dasd_release() and request function don't
acquire any mutex/semphone, so the conversion should be safe.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-20 09:05:45 -06:00
..
partitions Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block 2015-02-12 14:13:23 -08:00
bio-integrity.c block: fix regression where bio_integrity_process uses wrong bio_vec iterator 2014-12-02 08:15:21 -07:00
bio.c bio: skip atomic inc/dec of ->bi_cnt for most use cases 2015-05-05 13:32:49 -06:00
blk-cgroup.c blkcg: remove blkcg->id 2014-09-08 09:55:37 -06:00
blk-cgroup.h blkcg: remove blkcg->id 2014-09-08 09:55:37 -06:00
blk-core.c block: remove unused BIO_RW_BLOCK and BIO_EOF flags 2015-05-19 09:17:05 -06:00
blk-exec.c block: move PM request support to IDE 2015-05-05 13:40:42 -06:00
blk-flush.c blk-mq: support per-distpatch_queue flush machinery 2014-09-25 15:22:45 -06:00
blk-integrity.c block: Don't merge requests if integrity flags differ 2014-09-27 09:14:57 -06:00
blk-ioc.c block: Substitute rcu_access_pointer() for rcu_dereference_raw() 2014-02-18 12:21:26 -08:00
blk-iopoll.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-03 12:57:53 -07:00
blk-lib.c block: Quiesce zeroout wrapper 2015-02-05 10:14:54 -07:00
blk-map.c blk_rq_map_user(): use import_single_range() 2015-04-11 22:27:13 -04:00
blk-merge.c Fix bug in blk_rq_merge_ok 2015-03-20 08:50:41 -06:00
blk-mq-cpu.c blk-mq: add file comments and update copyright notices 2014-05-28 10:15:41 -06:00
blk-mq-cpumap.c blk-mq: Use all available hardware queues 2014-12-09 09:08:21 -07:00
blk-mq-sysfs.c blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk 2015-03-13 08:26:53 -06:00
blk-mq-tag.c blkmq: Fix NULL pointer deref when all reserved tags in 2015-03-18 17:06:18 -06:00
blk-mq-tag.h blk-mq: add tag allocation policy 2015-01-23 14:18:00 -07:00
blk-mq.c block: use an atomic_t for mq_freeze_depth 2015-05-19 09:12:59 -06:00
blk-mq.h blk-mq: release mq's kobjects in blk_release_queue() 2015-01-29 08:30:51 -08:00
blk-settings.c block: fix blk_stack_limits() regression due to lcm() change 2015-03-31 09:45:50 -06:00
blk-softirq.c block: fix regression with block enabled tagging 2014-04-09 21:54:06 -06:00
blk-sysfs.c blk-mq: release mq's kobjects in blk_release_queue() 2015-01-29 08:30:51 -08:00
blk-tag.c block: support different tag allocation policy 2015-01-23 14:15:46 -07:00
blk-throttle.c blk-throttle: check stats_cpu before reading it from sysfs 2015-02-20 22:11:58 -08:00
blk-timeout.c blk-mq: Allow requests to never expire 2015-01-08 08:59:01 -07:00
blk.h blk-mq: make plug work for mutiple disks and queues 2015-05-08 14:17:23 -06:00
bounce.c block: remove BIO_EOPNOTSUPP 2015-05-19 09:17:03 -06:00
bsg-lib.c
bsg.c block: Simplify bsg complete all 2015-02-04 09:57:52 -07:00
cfq-iosched.c cfq-iosched: handle failure of cfq group allocation 2015-02-09 10:22:39 -07:00
cmdline-parser.c block: remove unrelated header files and export symbol 2014-01-21 20:18:26 -08:00
compat_ioctl.c block, bdi: an active gendisk always has a request_queue associated with it 2014-09-08 10:00:35 -06:00
deadline-iosched.c block: Stop abusing csd.list for fifo_time 2014-02-24 14:46:32 -08:00
elevator.c block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM 2014-12-04 01:00:23 +01:00
genhd.c genhd: check for int overflow in disk_expand_part_tbl() 2014-11-19 13:09:07 -07:00
ioctl.c block: replace trylock with mutex_lock in blkdev_reread_part() 2015-05-20 09:05:45 -06:00
ioprio.c block: Fix computation of merged request priority 2014-10-31 08:30:43 -06:00
Kconfig block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00
Kconfig.iosched
Makefile block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00
noop-iosched.c
partition-generic.c block: Fix dev_t minor allocation lifetime 2014-09-03 15:01:02 -06:00
scsi_ioctl.c sg_io(): use import_iovec() 2015-04-11 22:27:13 -04:00
t10-pi.c block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00