linux/drivers/block
Junxiao Bi 4b422cb998 xen-blkfront: fix mq start/stop race
When ring buf full, hw queue will be stopped. While blkif interrupt consume
request and make free space in ring buf, hw queue will be started again.
But since start queue is protected by spin lock while stop not, that will
cause a race.

interrupt:                                      process:
blkif_interrupt()                               blkif_queue_rq()
 kick_pending_request_queues_locked()
   blk_mq_start_stopped_hw_queues()
      clear_bit(BLK_MQ_S_STOPPED, &hctx->state)
	                                             blk_mq_stop_hw_queue(hctx)
	  blk_mq_run_hw_queue(hctx, async)

If ring buf is made empty in this case, interrupt will never come, then the
hw queue will be stopped forever, all processes waiting for the pending io
in the queue will hung.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-07-25 11:30:59 -04:00
..
aoe block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
drbd Merge branch 'work.misc-set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 13:13:32 -07:00
mtip32xx Merge branch 'nvme-4.13' of git://git.infradead.org/nvme into for-linus 2017-07-10 11:44:34 -06:00
paride block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
rsxx block: don't bother with bounce limits for make_request drivers 2017-06-27 12:13:45 -06:00
xen-blkback Merge commit '8e8320c9315c' into for-4.13/block 2017-06-22 21:55:24 -06:00
zram zram: constify attribute_group structures. 2017-07-10 16:32:33 -07:00
amiflop.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
ataflop.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
brd.c ARM: fix rd_size declaration 2017-07-10 16:32:34 -07:00
cciss_cmd.h
cciss_scsi.c cciss: Remove kmalloc cast 2017-02-22 11:54:49 -07:00
cciss_scsi.h
cciss.c cciss: initialize struct scsi_req 2017-07-06 12:23:51 -06:00
cciss.h SCSI misc on 20170220 2017-02-21 11:51:42 -08:00
cryptoloop.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
DAC960.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
DAC960.h
floppy.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 20:57:13 -07:00
Kconfig libnvdimm for 4.12 2017-05-05 18:49:20 -07:00
loop.c Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 14:35:57 -07:00
loop.h loop: support 4k physical blocksize 2017-06-08 08:40:00 -06:00
Makefile block: remove the osdblk driver 2017-04-19 09:10:51 -06:00
nbd.c nbd: only set sndtimeo if we have a timeout set 2017-07-22 11:12:32 -06:00
null_blk.c null_blk: fix error flow for shared tags during module_init 2017-07-06 09:52:09 -06:00
pktcdvd.c driver core patches for 4.13-rc1 2017-07-03 20:27:48 -07:00
ps3disk.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
ps3vram.c blk: remove bio_set arg from blk_queue_split() 2017-06-18 12:40:59 -06:00
rbd_types.h rbd: RBD_V{1,2}_DATA_FORMAT macros 2017-02-20 12:16:15 +01:00
rbd.c rbd: use bio_clone_fast() instead of bio_clone() 2017-06-18 12:40:59 -06:00
skd_main.c block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
skd_s1120.h skd: fix formatting in skd_s1120.h 2013-11-08 09:10:30 -07:00
smart1,2.h
sunvdc.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
swim3.c block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
swim_asm.S
swim.c block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
sx8.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
umem.c blk: remove bio_set arg from blk_queue_split() 2017-06-18 12:40:59 -06:00
umem.h
virtio_blk.c virtio_blk: quiesce/unquiesce live IO when entering PM states 2017-07-06 09:49:34 +03:00
xen-blkfront.c xen-blkfront: fix mq start/stop race 2017-07-25 11:30:59 -04:00
xsysace.c block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
z2ram.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00