diff options
| -rw-r--r-- | block/blk-settings.c | 2 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 81 |
2 files changed, 29 insertions, 54 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 008947a13541..3c3e87bad6d3 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -21,7 +21,7 @@ void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) { - q->rq_timeout = timeout; + WRITE_ONCE(q->rq_timeout, timeout); } EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 4700ee168ed5..bc641ac71cde 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -172,12 +172,7 @@ QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(max_hw_sectors) #define QUEUE_SYSFS_SHOW_CONST(_name, _val) \ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page) \ { \ - ssize_t ret; \ - \ - mutex_lock(&disk->queue->sysfs_lock); \ - ret = sysfs_emit(page, "%d\n", _val); \ - mutex_unlock(&disk->queue->sysfs_lock); \ - return ret; \ + return sysfs_emit(page, "%d\n", _val); \ } /* deprecated fields */ @@ -266,17 +261,11 @@ QUEUE_SYSFS_FEATURE_SHOW(dax, BLK_FEAT_DAX); static ssize_t queue_poll_show(struct gendisk *disk, char *page) { - ssize_t ret; + if (queue_is_mq(disk->queue)) + return sysfs_emit(page, "%u\n", blk_mq_can_poll(disk->queue)); - mutex_lock(&disk->queue->sysfs_lock); - if (queue_is_mq(disk->queue)) { - ret = sysfs_emit(page, "%u\n", blk_mq_can_poll(disk->queue)); - } else { - ret = sysfs_emit(page, "%u\n", + return sysfs_emit(page, "%u\n", !!(disk->queue->limits.features & BLK_FEAT_POLL)); - } - mutex_unlock(&disk->queue->sysfs_lock); - return ret; } static ssize_t queue_zoned_show(struct gendisk *disk, char *page) @@ -288,12 +277,7 @@ static ssize_t queue_zoned_show(struct gendisk *disk, char *page) static ssize_t queue_nr_zones_show(struct gendisk *disk, char *page) { - ssize_t ret; - - mutex_lock(&disk->queue->sysfs_lock); - ret = queue_var_show(disk_nr_zones(disk), page); - mutex_unlock(&disk->queue->sysfs_lock); - return ret; + return queue_var_show(disk_nr_zones(disk), page); } static ssize_t queue_iostats_passthrough_show(struct gendisk *disk, char *page) @@ -320,13 +304,8 @@ static int queue_iostats_passthrough_store(struct gendisk *disk, static ssize_t queue_nomerges_show(struct gendisk *disk, char *page) { - ssize_t ret; - - mutex_lock(&disk->queue->sysfs_lock); - ret = queue_var_show((blk_queue_nomerges(disk->queue) << 1) | + return queue_var_show((blk_queue_nomerges(disk->queue) << 1) | blk_queue_noxmerges(disk->queue), page); - mutex_unlock(&disk->queue->sysfs_lock); - return ret; } static ssize_t queue_nomerges_store(struct gendisk *disk, const char *page, @@ -340,7 +319,6 @@ static ssize_t queue_nomerges_store(struct gendisk *disk, const char *page, if (ret < 0) return ret; - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q); blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); @@ -349,22 +327,16 @@ static ssize_t queue_nomerges_store(struct gendisk *disk, const char *page, else if (nm) blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); return ret; } static ssize_t queue_rq_affinity_show(struct gendisk *disk, char *page) { - ssize_t ret; - bool set, force; + bool set = test_bit(QUEUE_FLAG_SAME_COMP, &disk->queue->queue_flags); + bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &disk->queue->queue_flags); - mutex_lock(&disk->queue->sysfs_lock); - set = test_bit(QUEUE_FLAG_SAME_COMP, &disk->queue->queue_flags); - force = test_bit(QUEUE_FLAG_SAME_FORCE, &disk->queue->queue_flags); - ret = queue_var_show(set << force, page); - mutex_unlock(&disk->queue->sysfs_lock); - return ret; + return queue_var_show(set << force, page); } static ssize_t @@ -380,7 +352,12 @@ queue_rq_affinity_store(struct gendisk *disk, const char *page, size_t count) if (ret < 0) return ret; - mutex_lock(&q->sysfs_lock); + /* + * Here we update two queue flags each using atomic bitops, although + * updating two flags isn't atomic it should be harmless as those flags + * are accessed individually using atomic test_bit operation. So we + * don't grab any lock while updating these flags. + */ memflags = blk_mq_freeze_queue(q); if (val == 2) { blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); @@ -393,7 +370,6 @@ queue_rq_affinity_store(struct gendisk *disk, const char *page, size_t count) blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); } blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); #endif return ret; } @@ -411,30 +387,23 @@ static ssize_t queue_poll_store(struct gendisk *disk, const char *page, ssize_t ret = count; struct request_queue *q = disk->queue; - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); if (!(q->limits.features & BLK_FEAT_POLL)) { ret = -EINVAL; goto out; } + pr_info_ratelimited("writes to the poll attribute are ignored.\n"); pr_info_ratelimited("please use driver specific parameters instead.\n"); out: blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); - return ret; } static ssize_t queue_io_timeout_show(struct gendisk *disk, char *page) { - ssize_t ret; - - mutex_lock(&disk->queue->sysfs_lock); - ret = sysfs_emit(page, "%u\n", - jiffies_to_msecs(disk->queue->rq_timeout)); - mutex_unlock(&disk->queue->sysfs_lock); - return ret; + return sysfs_emit(page, "%u\n", + jiffies_to_msecs(READ_ONCE(disk->queue->rq_timeout))); } static ssize_t queue_io_timeout_store(struct gendisk *disk, const char *page, @@ -448,11 +417,9 @@ static ssize_t queue_io_timeout_store(struct gendisk *disk, const char *page, if (err || val == 0) return -EINVAL; - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); blk_queue_rq_timeout(q, msecs_to_jiffies(val)); blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); return count; } @@ -706,6 +673,10 @@ static struct attribute *queue_attrs[] = { * Attributes which are protected with q->sysfs_lock. */ &queue_ra_entry.attr, + + /* + * Attributes which don't require locking. + */ &queue_discard_zeroes_data_entry.attr, &queue_write_same_max_entry.attr, &queue_nr_zones_entry.attr, @@ -723,11 +694,15 @@ static struct attribute *blk_mq_queue_attrs[] = { */ &queue_requests_entry.attr, &elv_iosched_entry.attr, - &queue_rq_affinity_entry.attr, - &queue_io_timeout_entry.attr, #ifdef CONFIG_BLK_WBT &queue_wb_lat_entry.attr, #endif + /* + * Attributes which don't require locking. + */ + &queue_rq_affinity_entry.attr, + &queue_io_timeout_entry.attr, + NULL, }; |