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authorJoe Lawrence <joe.lawrence@stratus.com>2014-08-28 08:15:21 -0600
committerJens Axboe <axboe@fb.com>2014-08-28 10:03:46 -0600
commita492f075450f3ba87de36e5ffe92a9d0c7af9723 (patch)
tree61960a71c7fde0eee3d77cda460154d2f7715d2f /drivers/block
parenteb571eeade2598635f813b3284d02c13a380301e (diff)
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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/block')
-rw-r--r--drivers/block/paride/pd.c4
-rw-r--r--drivers/block/pktcdvd.c4
-rw-r--r--drivers/block/sx8.c2
3 files changed, 5 insertions, 5 deletions
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index ca831f741d89..d48715b287e6 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -722,8 +722,8 @@ static int pd_special_command(struct pd_unit *disk,
int err = 0;
rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT);
- if (!rq)
- return -ENODEV;
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->special = func;
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 7fa8c80e8982..09e628dafd9d 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -704,8 +704,8 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
WRITE : READ, __GFP_WAIT);
- if (!rq)
- return -ENODEV;
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
blk_rq_set_block_pc(rq);
if (cgc->buflen) {
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c
index d5e2d12b9d9e..5d552857de41 100644
--- a/drivers/block/sx8.c
+++ b/drivers/block/sx8.c
@@ -568,7 +568,7 @@ static struct carm_request *carm_get_special(struct carm_host *host)
return NULL;
rq = blk_get_request(host->oob_q, WRITE /* bogus */, GFP_KERNEL);
- if (!rq) {
+ if (IS_ERR(rq)) {
spin_lock_irqsave(&host->lock, flags);
carm_put_request(host, crq);
spin_unlock_irqrestore(&host->lock, flags);