diff options
| -rw-r--r-- | block/blk-core.c | 3 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 28 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 5 |
3 files changed, 34 insertions, 2 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index f0640d7f800f..b4131d29148c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2111,7 +2111,8 @@ static bool blk_update_bidi_request(struct request *rq, int error, blk_update_request(rq->next_rq, error, bidi_bytes)) return true; - add_disk_randomness(rq->rq_disk); + if (blk_queue_add_random(rq->q)) + add_disk_randomness(rq->rq_disk); return false; } diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 306759bbdf1b..58b53c354c2c 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -250,6 +250,27 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) return ret; } +static ssize_t queue_random_show(struct request_queue *q, char *page) +{ + return queue_var_show(blk_queue_add_random(q), page); +} + +static ssize_t queue_random_store(struct request_queue *q, const char *page, + size_t count) +{ + unsigned long val; + ssize_t ret = queue_var_store(&val, page, count); + + spin_lock_irq(q->queue_lock); + if (val) + queue_flag_set(QUEUE_FLAG_ADD_RANDOM, q); + else + queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + static ssize_t queue_iostats_show(struct request_queue *q, char *page) { return queue_var_show(blk_queue_io_stat(q), page); @@ -374,6 +395,12 @@ static struct queue_sysfs_entry queue_iostats_entry = { .store = queue_iostats_store, }; +static struct queue_sysfs_entry queue_random_entry = { + .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR }, + .show = queue_random_show, + .store = queue_random_store, +}; + static struct attribute *default_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -394,6 +421,7 @@ static struct attribute *default_attrs[] = { &queue_nomerges_entry.attr, &queue_rq_affinity_entry.attr, &queue_iostats_entry.attr, + &queue_random_entry.attr, NULL, }; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 09a840264d6f..b8224ea4a5de 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -467,11 +467,13 @@ struct request_queue #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */ +#define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_CLUSTER) | \ (1 << QUEUE_FLAG_STACKABLE) | \ - (1 << QUEUE_FLAG_SAME_COMP)) + (1 << QUEUE_FLAG_SAME_COMP) | \ + (1 << QUEUE_FLAG_ADD_RANDOM)) static inline int queue_is_locked(struct request_queue *q) { @@ -596,6 +598,7 @@ enum { test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) +#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) #define blk_queue_flushing(q) ((q)->ordseq) #define blk_queue_stackable(q) \ test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) |