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authorJoe Lawrence <joe.lawrence@stratus.com>2014-08-28 18:15:21 +0400
committerJens Axboe <axboe@fb.com>2014-08-28 20:03:46 +0400
commita492f075450f3ba87de36e5ffe92a9d0c7af9723 (patch)
tree61960a71c7fde0eee3d77cda460154d2f7715d2f /drivers/scsi/device_handler
parenteb571eeade2598635f813b3284d02c13a380301e (diff)
downloadlinux-a492f075450f3ba87de36e5ffe92a9d0c7af9723.tar.xz
block,scsi: fixup blk_get_request dead queue scenarios
The blk_get_request function may fail in low-memory conditions or during device removal (even if __GFP_WAIT is set). To distinguish between these errors, modify the blk_get_request call stack to return the appropriate ERR_PTR. Verify that all callers check the return status and consider IS_ERR instead of a simple NULL pointer check. For consistency, make a similar change to the blk_mq_alloc_request leg of blk_get_request. It may fail if the queue is dead, or the caller was unwilling to wait. Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd] Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd] Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/scsi/device_handler')
-rw-r--r--drivers/scsi/device_handler/scsi_dh_alua.c2
-rw-r--r--drivers/scsi/device_handler/scsi_dh_emc.c2
-rw-r--r--drivers/scsi/device_handler/scsi_dh_hp_sw.c4
-rw-r--r--drivers/scsi/device_handler/scsi_dh_rdac.c2
4 files changed, 5 insertions, 5 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 7bcf67eec921..e99507ed0e3c 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -115,7 +115,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,
rq = blk_get_request(q, rw, GFP_NOIO);
- if (!rq) {
+ if (IS_ERR(rq)) {
sdev_printk(KERN_INFO, sdev,
"%s: blk_get_request failed\n", __func__);
return NULL;
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index 6f07f7fe3aa1..84765384c47c 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -275,7 +275,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,
rq = blk_get_request(sdev->request_queue,
(cmd != INQUIRY) ? WRITE : READ, GFP_NOIO);
- if (!rq) {
+ if (IS_ERR(rq)) {
sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
return NULL;
}
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index e9d9fea9e272..4ee2759f5299 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -117,7 +117,7 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
retry:
req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
- if (!req)
+ if (IS_ERR(req))
return SCSI_DH_RES_TEMP_UNAVAIL;
blk_rq_set_block_pc(req);
@@ -247,7 +247,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
struct request *req;
req = blk_get_request(h->sdev->request_queue, WRITE, GFP_ATOMIC);
- if (!req)
+ if (IS_ERR(req))
return SCSI_DH_RES_TEMP_UNAVAIL;
blk_rq_set_block_pc(req);
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 826069db9848..1b5bc9293e37 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -274,7 +274,7 @@ static struct request *get_rdac_req(struct scsi_device *sdev,
rq = blk_get_request(q, rw, GFP_NOIO);
- if (!rq) {
+ if (IS_ERR(rq)) {
sdev_printk(KERN_INFO, sdev,
"get_rdac_req: blk_get_request failed.\n");
return NULL;