• Rusty Russell's avatar
    virtio_scsi: don't call virtqueue_add_sgs(... GFP_NOIO) holding spinlock. · c77fba9a
    Rusty Russell authored
    This triggers every time we do a SCSI abort:
    
    virtscsi_tmf -> virtscsi_kick_cmd (grab lock and call) -> virtscsi_add_cmd
    	-> virtqueue_add_sgs (GFP_NOIO)
    
    Logs look like this:
     sd 0:0:0:0: [sda] abort
     BUG: sleeping function called from invalid context at mm/slub.c:966
     in_atomic(): 1, irqs_disabled(): 1, pid: 6, name: kworker/u2:0
     3 locks held by kworker/u2:0/6:
      #0:  ("scsi_tmf_%d"shost->host_no){......}, at: [<c0153180>] process_one_work+0xe0/0x3d0
      #1:  ((&(&cmd->abort_work)->work)){......}, at: [<c0153180>] process_one_work+0xe0/0x3d0
      #2:  (&(&virtscsi_vq->vq_lock)->rlock){......}, at: [<c043f508>] virtscsi_kick_cmd+0x18/0x1b0
     CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.15.0-rc5+ #110
     Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-rc1-0-gb1d4dc9-20140515_140003-nilsson.home.kraxel.org 04/01/2014
     Workqueue: scsi_tmf_0 scmd_eh_abort_handler
    Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
    Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    c77fba9a
virtio_scsi.c 26.4 KB