• Ming Lei's avatar
    scsi: core: Run queue in case of I/O resource contention failure · 3f0dcfbc
    Ming Lei authored
    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: default avatarBart Van Assche <bvanassche@acm.org>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    3f0dcfbc
scsi_lib.c 82.9 KB