linux/block
Dan Williams 3ef28e83ab block: generic request_queue reference counting
Allow pmem, and other synchronous/bio-based block drivers, to fallback
on a per-cpu reference count managed by the core for tracking queue
live/dead state.

The existing per-cpu reference count for the blk_mq case is promoted to
be used in all block i/o scenarios.  This involves initializing it by
default, waiting for it to drop to zero at exit, and holding a live
reference over the invocation of q->make_request_fn() in
generic_make_request().  The blk_mq code continues to take its own
reference per blk_mq request and retains the ability to freeze the
queue, but the check that the queue is frozen is moved to
generic_make_request().

This fixes crash signatures like the following:

 BUG: unable to handle kernel paging request at ffff880140000000
 [..]
 Call Trace:
  [<ffffffff8145e8bf>] ? copy_user_handle_tail+0x5f/0x70
  [<ffffffffa004e1e0>] pmem_do_bvec.isra.11+0x70/0xf0 [nd_pmem]
  [<ffffffffa004e331>] pmem_make_request+0xd1/0x200 [nd_pmem]
  [<ffffffff811c3162>] ? mempool_alloc+0x72/0x1a0
  [<ffffffff8141f8b6>] generic_make_request+0xd6/0x110
  [<ffffffff8141f966>] submit_bio+0x76/0x170
  [<ffffffff81286dff>] submit_bh_wbc+0x12f/0x160
  [<ffffffff81286e62>] submit_bh+0x12/0x20
  [<ffffffff813395bd>] jbd2_write_superblock+0x8d/0x170
  [<ffffffff8133974d>] jbd2_mark_journal_empty+0x5d/0x90
  [<ffffffff813399cb>] jbd2_journal_destroy+0x24b/0x270
  [<ffffffff810bc4ca>] ? put_pwq_unlocked+0x2a/0x30
  [<ffffffff810bc6f5>] ? destroy_workqueue+0x225/0x250
  [<ffffffff81303494>] ext4_put_super+0x64/0x360
  [<ffffffff8124ab1a>] generic_shutdown_super+0x6a/0xf0

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:41 -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: Reduce the size of struct blk_integrity 2015-10-21 14:42:39 -06:00
bio.c Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block 2015-09-10 18:56:14 -07:00
blk-cgroup.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2015-09-19 18:57:09 -07:00
blk-core.c block: generic request_queue reference counting 2015-10-21 14:43:41 -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: fix race between timeout and freeing request 2015-08-15 09:45:21 -06:00
blk-integrity.c block: Inline blk_integrity in struct gendisk 2015-10-21 14:42:42 -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: remove split code in blkdev_issue_{discard,write_same} 2015-08-13 12:31:47 -06:00
blk-map.c block: Copy a user iovec if it includes gaps 2015-09-11 09:03:50 -06:00
blk-merge.c block: blk-merge: fast-clone bio when splitting rw bios 2015-09-17 09:58:38 -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: avoid inserting requests before establishing new mapping 2015-09-29 11:32:50 -06:00
blk-mq-sysfs.c block: generic request_queue reference counting 2015-10-21 14:43:41 -06:00
blk-mq-tag.c blk-mq: factor out a helper to iterate all tags for a request_queue 2015-10-01 10:10:57 +02:00
blk-mq-tag.h blk-mq: factor out a helper to iterate all tags for a request_queue 2015-10-01 10:10:57 +02:00
blk-mq.c block: generic request_queue reference counting 2015-10-21 14:43:41 -06:00
blk-mq.h blk-mq: avoid inserting requests before establishing new mapping 2015-09-29 11:32:50 -06:00
blk-settings.c Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block 2015-09-02 13:10:25 -07:00
blk-softirq.c block: fix regression with block enabled tagging 2014-04-09 21:54:06 -06:00
blk-sysfs.c block: generic request_queue reference counting 2015-10-21 14:43:41 -06:00
blk-tag.c block: support different tag allocation policy 2015-01-23 14:15:46 -07:00
blk-throttle.c blkcg: implement interface for the unified hierarchy 2015-08-18 15:49:35 -07:00
blk-timeout.c blk-mq: Allow requests to never expire 2015-01-08 08:59:01 -07:00
blk.h block: generic request_queue reference counting 2015-10-21 14:43:41 -06:00
bounce.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2015-09-19 18:57:09 -07:00
bsg-lib.c bsg: Remove unused function bsg_goose_queue() 2012-12-06 14:33:02 +01:00
bsg.c block: Simplify bsg complete all 2015-02-04 09:57:52 -07:00
cfq-iosched.c blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy 2015-08-18 15:49:36 -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 Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
genhd.c block: Inline blk_integrity in struct gendisk 2015-10-21 14:42:42 -06:00
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 blkcg: make CONFIG_BLK_CGROUP bool 2012-03-06 21:27:21 +01:00
Makefile block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00
noop-iosched.c elevator: Fix a race in elevator switching 2013-07-03 13:25:24 +02:00
partition-generic.c block: Inline blk_integrity in struct gendisk 2015-10-21 14:42:42 -06:00
scsi_ioctl.c block: fix bogus EFAULT error from SG_IO ioctl 2015-06-27 11:43:34 -06:00
t10-pi.c block: Consolidate static integrity profile properties 2015-10-21 14:42:38 -06:00