diff options
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/ll_rw_blk.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c index 67431f280154..5caebe2cf0a1 100644 --- a/drivers/block/ll_rw_blk.c +++ b/drivers/block/ll_rw_blk.c | |||
@@ -1867,19 +1867,20 @@ static void freed_request(request_queue_t *q, int rw) | |||
1867 | 1867 | ||
1868 | #define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist) | 1868 | #define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist) |
1869 | /* | 1869 | /* |
1870 | * Get a free request, queue_lock must not be held | 1870 | * Get a free request, queue_lock must be held. |
1871 | * Returns NULL on failure, with queue_lock held. | ||
1872 | * Returns !NULL on success, with queue_lock *not held*. | ||
1871 | */ | 1873 | */ |
1872 | static struct request *get_request(request_queue_t *q, int rw, struct bio *bio, | 1874 | static struct request *get_request(request_queue_t *q, int rw, struct bio *bio, |
1873 | int gfp_mask) | 1875 | int gfp_mask) |
1874 | { | 1876 | { |
1875 | struct request *rq = NULL; | 1877 | struct request *rq = NULL; |
1876 | struct request_list *rl = &q->rq; | 1878 | struct request_list *rl = &q->rq; |
1877 | struct io_context *ioc = get_io_context(gfp_mask); | 1879 | struct io_context *ioc = get_io_context(GFP_ATOMIC); |
1878 | 1880 | ||
1879 | if (unlikely(test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))) | 1881 | if (unlikely(test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))) |
1880 | goto out; | 1882 | goto out; |
1881 | 1883 | ||
1882 | spin_lock_irq(q->queue_lock); | ||
1883 | if (rl->count[rw]+1 >= q->nr_requests) { | 1884 | if (rl->count[rw]+1 >= q->nr_requests) { |
1884 | /* | 1885 | /* |
1885 | * The queue will fill after this allocation, so set it as | 1886 | * The queue will fill after this allocation, so set it as |
@@ -1907,7 +1908,6 @@ static struct request *get_request(request_queue_t *q, int rw, struct bio *bio, | |||
1907 | * The queue is full and the allocating process is not a | 1908 | * The queue is full and the allocating process is not a |
1908 | * "batcher", and not exempted by the IO scheduler | 1909 | * "batcher", and not exempted by the IO scheduler |
1909 | */ | 1910 | */ |
1910 | spin_unlock_irq(q->queue_lock); | ||
1911 | goto out; | 1911 | goto out; |
1912 | } | 1912 | } |
1913 | 1913 | ||
@@ -1950,7 +1950,6 @@ rq_starved: | |||
1950 | if (unlikely(rl->count[rw] == 0)) | 1950 | if (unlikely(rl->count[rw] == 0)) |
1951 | rl->starved[rw] = 1; | 1951 | rl->starved[rw] = 1; |
1952 | 1952 | ||
1953 | spin_unlock_irq(q->queue_lock); | ||
1954 | goto out; | 1953 | goto out; |
1955 | } | 1954 | } |
1956 | 1955 | ||
@@ -1967,6 +1966,8 @@ out: | |||
1967 | /* | 1966 | /* |
1968 | * No available requests for this queue, unplug the device and wait for some | 1967 | * No available requests for this queue, unplug the device and wait for some |
1969 | * requests to become available. | 1968 | * requests to become available. |
1969 | * | ||
1970 | * Called with q->queue_lock held, and returns with it unlocked. | ||
1970 | */ | 1971 | */ |
1971 | static struct request *get_request_wait(request_queue_t *q, int rw, | 1972 | static struct request *get_request_wait(request_queue_t *q, int rw, |
1972 | struct bio *bio) | 1973 | struct bio *bio) |
@@ -1986,7 +1987,8 @@ static struct request *get_request_wait(request_queue_t *q, int rw, | |||
1986 | if (!rq) { | 1987 | if (!rq) { |
1987 | struct io_context *ioc; | 1988 | struct io_context *ioc; |
1988 | 1989 | ||
1989 | generic_unplug_device(q); | 1990 | __generic_unplug_device(q); |
1991 | spin_unlock_irq(q->queue_lock); | ||
1990 | io_schedule(); | 1992 | io_schedule(); |
1991 | 1993 | ||
1992 | /* | 1994 | /* |
@@ -1998,6 +2000,8 @@ static struct request *get_request_wait(request_queue_t *q, int rw, | |||
1998 | ioc = get_io_context(GFP_NOIO); | 2000 | ioc = get_io_context(GFP_NOIO); |
1999 | ioc_set_batching(q, ioc); | 2001 | ioc_set_batching(q, ioc); |
2000 | put_io_context(ioc); | 2002 | put_io_context(ioc); |
2003 | |||
2004 | spin_lock_irq(q->queue_lock); | ||
2001 | } | 2005 | } |
2002 | finish_wait(&rl->wait[rw], &wait); | 2006 | finish_wait(&rl->wait[rw], &wait); |
2003 | } | 2007 | } |
@@ -2011,14 +2015,18 @@ struct request *blk_get_request(request_queue_t *q, int rw, int gfp_mask) | |||
2011 | 2015 | ||
2012 | BUG_ON(rw != READ && rw != WRITE); | 2016 | BUG_ON(rw != READ && rw != WRITE); |
2013 | 2017 | ||
2014 | if (gfp_mask & __GFP_WAIT) | 2018 | spin_lock_irq(q->queue_lock); |
2019 | if (gfp_mask & __GFP_WAIT) { | ||
2015 | rq = get_request_wait(q, rw, NULL); | 2020 | rq = get_request_wait(q, rw, NULL); |
2016 | else | 2021 | } else { |
2017 | rq = get_request(q, rw, NULL, gfp_mask); | 2022 | rq = get_request(q, rw, NULL, gfp_mask); |
2023 | if (!rq) | ||
2024 | spin_unlock_irq(q->queue_lock); | ||
2025 | } | ||
2026 | /* q->queue_lock is unlocked at this point */ | ||
2018 | 2027 | ||
2019 | return rq; | 2028 | return rq; |
2020 | } | 2029 | } |
2021 | |||
2022 | EXPORT_SYMBOL(blk_get_request); | 2030 | EXPORT_SYMBOL(blk_get_request); |
2023 | 2031 | ||
2024 | /** | 2032 | /** |
@@ -2605,9 +2613,10 @@ static int __make_request(request_queue_t *q, struct bio *bio) | |||
2605 | get_rq: | 2613 | get_rq: |
2606 | /* | 2614 | /* |
2607 | * Grab a free request. This is might sleep but can not fail. | 2615 | * Grab a free request. This is might sleep but can not fail. |
2616 | * Returns with the queue unlocked. | ||
2608 | */ | 2617 | */ |
2609 | spin_unlock_irq(q->queue_lock); | ||
2610 | req = get_request_wait(q, rw, bio); | 2618 | req = get_request_wait(q, rw, bio); |
2619 | |||
2611 | /* | 2620 | /* |
2612 | * After dropping the lock and possibly sleeping here, our request | 2621 | * After dropping the lock and possibly sleeping here, our request |
2613 | * may now be mergeable after it had proven unmergeable (above). | 2622 | * may now be mergeable after it had proven unmergeable (above). |