a0ba41317c
[ Upstream commit 3f0dcfbcd2e162fc0a11c1f59b7acd42ee45f126 ] I/O requests may be held in scheduler queue because of resource contention. The starvation scenario was handled properly in the regular completion path but we failed to account for it during I/O submission. This lead to the hang captured below. Make sure we run the queue when resource contention is encountered in the submission path. [ 39.054963] scsi 13:0:0:0: rejecting I/O to dead device [ 39.058700] scsi 13:0:0:0: rejecting I/O to dead device [ 39.087855] sd 13:0:0:1: [sdd] Synchronizing SCSI cache [ 39.088909] scsi 13:0:0:1: rejecting I/O to dead device [ 39.095351] scsi 13:0:0:1: rejecting I/O to dead device [ 39.096962] scsi 13:0:0:1: rejecting I/O to dead device [ 247.021859] INFO: task scsi-stress-rem:813 blocked for more than 122 seconds. [ 247.023258] Not tainted 5.8.0-rc2 #8 [ 247.024069] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 247.025331] scsi-stress-rem D 0 813 802 0x00004000 [ 247.025334] Call Trace: [ 247.025354] __schedule+0x504/0x55f [ 247.027987] schedule+0x72/0xa8 [ 247.027991] blk_mq_freeze_queue_wait+0x63/0x8c [ 247.027994] ? do_wait_intr_irq+0x7a/0x7a [ 247.027996] blk_cleanup_queue+0x4b/0xc9 [ 247.028000] __scsi_remove_device+0xf6/0x14e [ 247.028002] scsi_remove_device+0x21/0x2b [ 247.029037] sdev_store_delete+0x58/0x7c [ 247.029041] kernfs_fop_write+0x10d/0x14f [ 247.031281] vfs_write+0xa2/0xdf [ 247.032670] ksys_write+0x6b/0xb3 [ 247.032673] do_syscall_64+0x56/0x82 [ 247.034053] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 247.034059] RIP: 0033:0x7f69f39e9008 [ 247.036330] Code: Bad RIP value. [ 247.036331] RSP: 002b:00007ffdd8116498 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 247.037613] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f69f39e9008 [ 247.039714] RDX: 0000000000000002 RSI: 000055cde92a0ab0 RDI: 0000000000000001 [ 247.039715] RBP: 000055cde92a0ab0 R08: 000000000000000a R09: 00007f69f3a79e80 [ 247.039716] R10: 000000000000000a R11: 0000000000000246 R12: 00007f69f3abb780 [ 247.039717] R13: 0000000000000002 R14: 00007f69f3ab6740 R15: 0000000000000002 Link: https://lore.kernel.org/r/20200720025435.812030-1-ming.lei@redhat.com Cc: linux-block@vger.kernel.org Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.