diff options
| author | Joe Lawrence <joe.lawrence@stratus.com> | 2014-08-28 08:15:21 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-08-28 10:03:46 -0600 |
| commit | a492f075450f3ba87de36e5ffe92a9d0c7af9723 (patch) | |
| tree | 61960a71c7fde0eee3d77cda460154d2f7715d2f /block/blk-mq.c | |
| parent | eb571eeade2598635f813b3284d02c13a380301e (diff) | |
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 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 5189cb1e478a..940aa8a34b70 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -218,9 +218,11 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, struct blk_mq_hw_ctx *hctx; struct request *rq; struct blk_mq_alloc_data alloc_data; + int ret; - if (blk_mq_queue_enter(q)) - return NULL; + ret = blk_mq_queue_enter(q); + if (ret) + return ERR_PTR(ret); ctx = blk_mq_get_ctx(q); hctx = q->mq_ops->map_queue(q, ctx->cpu); @@ -240,6 +242,8 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, ctx = alloc_data.ctx; } blk_mq_put_ctx(ctx); + if (!rq) + return ERR_PTR(-EWOULDBLOCK); return rq; } EXPORT_SYMBOL(blk_mq_alloc_request); |