block,scsi: fixup blk_get_request dead queue scenarios

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index c359d72e9d76f24a44b7c4b6b8c36c6677436191..93603e6ff479df3ea38a8e8925e429c2a096e504 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -933,9 +933,9 @@ static struct io_context *rq_ioc(struct bio *bio)
  * Get a free request from @q.  This function may fail under memory
  * pressure or if @q is dead.
  *
- * Must be callled with @q->queue_lock held and,
- * Returns %NULL on failure, with @q->queue_lock held.
- * Returns !%NULL on success, with @q->queue_lock *not held*.
+ * Must be called with @q->queue_lock held and,
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *__get_request(struct request_list *rl, int rw_flags,
                                     struct bio *bio, gfp_t gfp_mask)
@@ -949,7 +949,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
        int may_queue;
 
        if (unlikely(blk_queue_dying(q)))
-               return NULL;
+               return ERR_PTR(-ENODEV);
 
        may_queue = elv_may_queue(q, rw_flags);
        if (may_queue == ELV_MQUEUE_NO)
@@ -974,7 +974,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
                                         * process is not a "batcher", and not
                                         * exempted by the IO scheduler
                                         */
-                                       return NULL;
+                                       return ERR_PTR(-ENOMEM);
                                }
                        }
                }
@@ -992,7 +992,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
         * allocated with any setting of ->nr_requests
         */
        if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        q->nr_rqs[is_sync]++;
        rl->count[is_sync]++;
@@ -1097,7 +1097,7 @@ fail_alloc:
 rq_starved:
        if (unlikely(rl->count[is_sync] == 0))
                rl->starved[is_sync] = 1;
-       return NULL;
+       return ERR_PTR(-ENOMEM);
 }
 
 /**
@@ -1110,9 +1110,9 @@ rq_starved:
  * Get a free request from @q.  If %__GFP_WAIT is set in @gfp_mask, this
  * function keeps retrying under memory pressure and fails iff @q is dead.
  *
- * Must be callled with @q->queue_lock held and,
- * Returns %NULL on failure, with @q->queue_lock held.
- * Returns !%NULL on success, with @q->queue_lock *not held*.
+ * Must be called with @q->queue_lock held and,
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *get_request(struct request_queue *q, int rw_flags,
                                   struct bio *bio, gfp_t gfp_mask)
@@ -1125,12 +1125,12 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
        rl = blk_get_rl(q, bio);        /* transferred to @rq on success */
 retry:
        rq = __get_request(rl, rw_flags, bio, gfp_mask);
-       if (rq)
+       if (!IS_ERR(rq))
                return rq;
 
        if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) {
                blk_put_rl(rl);
-               return NULL;
+               return rq;
        }
 
        /* wait on @rl and retry */
@@ -1167,7 +1167,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
 
        spin_lock_irq(q->queue_lock);
        rq = get_request(q, rw, NULL, gfp_mask);
-       if (!rq)
+       if (IS_ERR(rq))
                spin_unlock_irq(q->queue_lock);
        /* q->queue_lock is unlocked at this point */
 
@@ -1219,8 +1219,8 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio,
 {
        struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
 
-       if (unlikely(!rq))
-               return ERR_PTR(-ENOMEM);
+       if (IS_ERR(rq))
+               return rq;
 
        blk_rq_set_block_pc(rq);
 
@@ -1615,8 +1615,8 @@ get_rq:
         * Returns with the queue unlocked.
         */
        req = get_request(q, rw_flags, bio, GFP_NOIO);
-       if (unlikely(!req)) {
-               bio_endio(bio, -ENODEV);        /* @q is dead */
+       if (IS_ERR(req)) {
+               bio_endio(bio, PTR_ERR(req));   /* @q is dead */
                goto out_unlock;
        }