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virtio_scsi: don't call virtqueue_add_sgs(... GFP_NOIO) holding spinlock. 

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: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Rusty Russell 2014-05-21 11:25:04 +09:30
parent a17597d3b4
commit c77fba9ab0
1 changed files with 6 additions and 9 deletions
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15
drivers/scsi/virtio_scsi.c
View File

@ -433,11 +433,10 @@ static void virtscsi_event_done(struct virtqueue *vq)
* @cmd : command structure
* @req_size : size of the request buffer
* @resp_size : size of the response buffer
* @gfp : flags to use for memory allocations
*/
static int virtscsi_add_cmd(struct virtqueue *vq,
struct virtio_scsi_cmd *cmd,
size_t req_size, size_t resp_size, gfp_t gfp)
size_t req_size, size_t resp_size)
{
struct scsi_cmnd *sc = cmd->sc;
struct scatterlist *sgs[4], req, resp;
@ -469,19 +468,19 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
if (in)
sgs[out_num + in_num++] = in->sgl;
return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
}
static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
struct virtio_scsi_cmd *cmd,
size_t req_size, size_t resp_size, gfp_t gfp)
size_t req_size, size_t resp_size)
{
unsigned long flags;
int err;
bool needs_kick = false;
spin_lock_irqsave(&vq->vq_lock, flags);
err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
if (!err)
needs_kick = virtqueue_kick_prepare(vq->vq);
@ -530,8 +529,7 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
if (virtscsi_kick_cmd(req_vq, cmd,
sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
GFP_ATOMIC) == 0)
sizeof cmd->req.cmd, sizeof cmd->resp.cmd) == 0)
ret = 0;
else
mempool_free(cmd, virtscsi_cmd_pool);
@ -596,8 +594,7 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
cmd->comp = &comp;
if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
GFP_NOIO) < 0)
sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
goto out;
wait_for_completion(&comp);