diff options
| -rw-r--r-- | block/blk-settings.c | 22 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 2 |
2 files changed, 24 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 127f82551855..5eeb9e0d256e 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -640,6 +640,28 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, EXPORT_SYMBOL(blk_stack_limits); /** + * bdev_stack_limits - adjust queue limits for stacked drivers + * @t: the stacking driver limits (top device) + * @bdev: the component block_device (bottom) + * @start: first data sector within component device + * + * Description: + * Merges queue limits for a top device and a block_device. Returns + * 0 if alignment didn't change. Returns -1 if adding the bottom + * device caused misalignment. + */ +int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, + sector_t start) +{ + struct request_queue *bq = bdev_get_queue(bdev); + + start += get_start_sect(bdev); + + return blk_stack_limits(t, &bq->limits, start << 9); +} +EXPORT_SYMBOL(bdev_stack_limits); + +/** * disk_stack_limits - adjust queue limits for stacked drivers * @disk: MD/DM gendisk (top) * @bdev: the underlying block device (bottom) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a41bcc8e140f..5c8018977efa 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -938,6 +938,8 @@ extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); extern void blk_set_default_limits(struct queue_limits *lim); extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, sector_t offset); +extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, + sector_t offset); extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, sector_t offset); extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); |