svn commit: r344987 - head/sys/dev/smartpqi

[Edward Tomasz Napierala]

Author: trasz
Date: Sun Mar 10 23:05:38 2019
New Revision: 344987
URL: https://svnweb.freebsd.org/changeset/base/344987

Log:
  Fix crash in low memory conditions.  Usual backtrace looked
  like this:
  
  pqisrc_build_sgl() at pqisrc_build_sgl+0x8d/frame 0xfffffe009e8b7a00
  pqisrc_build_raid_io() at pqisrc_build_raid_io+0x231/frame 0xfffffe009e8b7a40
  pqisrc_build_send_io() at pqisrc_build_send_io+0x375/frame 0xfffffe009e8b7b00
  pqi_request_map_helper() at pqi_request_map_helper+0x282/frame 0xfffffe009e8b7ba0
  bus_dmamap_load_ccb() at bus_dmamap_load_ccb+0xd7/frame 0xfffffe009e8b7c00
  pqi_map_request() at pqi_map_request+0x9b/frame 0xfffffe009e8b7c70
  pqisrc_io_start() at pqisrc_io_start+0x55c/frame 0xfffffe009e8b7d50
  smartpqi_cam_action() at smartpqi_cam_action+0xb8/frame 0xfffffe009e8b7de0
  xpt_run_devq() at xpt_run_devq+0x30a/frame 0xfffffe009e8b7e40
  xpt_action_default() at xpt_action_default+0x94b/frame 0xfffffe009e8b7e90
  dastart() at dastart+0x33b/frame 0xfffffe009e8b7ee0
  xpt_run_allocq() at xpt_run_allocq+0x1a2/frame 0xfffffe009e8b7f30
  dastrategy() at dastrategy+0x71/frame 0xfffffe009e8b7f60
  g_disk_start() at g_disk_start+0x351/frame 0xfffffe009e8b7fc0
  g_io_request() at g_io_request+0x3cf/frame 0xfffffe009e8b8010
  g_part_start() at g_part_start+0x120/frame 0xfffffe009e8b8090
  g_io_request() at g_io_request+0x3cf/frame 0xfffffe009e8b80e0
  zio_vdev_io_start() at zio_vdev_io_start+0x4b2/frame 0xfffffe009e8b8140
  zio_execute() at zio_execute+0x17c/frame 0xfffffe009e8b8180
  zio_nowait() at zio_nowait+0xc4/frame 0xfffffe009e8b81b0
  vdev_queue_io_done() at vdev_queue_io_done+0x138/frame 0xfffffe009e8b81f0
  zio_vdev_io_done() at zio_vdev_io_done+0x151/frame 0xfffffe009e8b8220
  zio_execute() at zio_execute+0x17c/frame 0xfffffe009e8b8260
  taskqueue_run_locked() at taskqueue_run_locked+0x10c/frame 0xfffffe009e8b82c0
  taskqueue_thread_loop() at taskqueue_thread_loop+0x88/frame 0xfffffe009e8b82f0
  fork_exit() at fork_exit+0x84/frame 0xfffffe009e8b8330
  fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe009e8b8330
  
  Reviewed by:	deepak.ukey_microsemi.com, sbruno
  MFC after:	2 weeks
  Sponsored by:	Klara Inc.
  Differential Revision:	https://reviews.freebsd.org/D19470

Modified:
  head/sys/dev/smartpqi/smartpqi_cam.c

Modified: head/sys/dev/smartpqi/smartpqi_cam.c
==============================================================================
--- head/sys/dev/smartpqi/smartpqi_cam.c	Sun Mar 10 21:43:13 2019	(r344986)
+++ head/sys/dev/smartpqi/smartpqi_cam.c	Sun Mar 10 23:05:38 2019	(r344987)
@@ -483,13 +483,21 @@ pqi_request_map_helper(void *arg, bus_dma_segment_t *s
 	}
 
 	rcb->sgt = os_mem_alloc(softs, nseg * sizeof(rcb_t));
+	if (rcb->sgt == NULL) {
+		xpt_freeze_simq(softs->os_specific.sim, 1);
+		rcb->cm_ccb->ccb_h.status |= (CAM_REQUEUE_REQ|
+						CAM_RELEASE_SIMQ);
+		DBG_ERR_BTL(rcb->dvp, "os_mem_alloc() failed; nseg = %d\n", nseg);
+		pqi_unmap_request(rcb);
+		xpt_done((union ccb *)rcb->cm_ccb);
+		return;
+	}
+
 	rcb->nseg = nseg;
-	if (rcb->sgt != NULL) {
-		for (int i = 0; i < nseg; i++) {
-			rcb->sgt[i].addr = segs[i].ds_addr;
-			rcb->sgt[i].len = segs[i].ds_len;
-			rcb->sgt[i].flags = 0;
-		}
+	for (int i = 0; i < nseg; i++) {
+		rcb->sgt[i].addr = segs[i].ds_addr;
+		rcb->sgt[i].len = segs[i].ds_len;
+		rcb->sgt[i].flags = 0;
 	}
 
 	if (rcb->data_dir == SOP_DATA_DIR_FROM_DEVICE)