diff options
Diffstat (limited to 'block/blk-settings.c')
| -rw-r--r-- | block/blk-settings.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 5d21239bc859..f1a1795a5683 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -113,6 +113,7 @@ void blk_set_default_limits(struct queue_limits *lim) lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; + lim->chunk_sectors = 0; lim->max_write_same_sectors = 0; lim->max_discard_sectors = 0; lim->discard_granularity = 0; @@ -277,6 +278,26 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto EXPORT_SYMBOL(blk_queue_max_hw_sectors); /** + * blk_queue_chunk_sectors - set size of the chunk for this queue + * @q: the request queue for the device + * @chunk_sectors: chunk sectors in the usual 512b unit + * + * Description: + * If a driver doesn't want IOs to cross a given chunk size, it can set + * this limit and prevent merging across chunks. Note that the chunk size + * must currently be a power-of-2 in sectors. Also note that the block + * layer must accept a page worth of data at any offset. So if the + * crossing of chunks is a hard limitation in the driver, it must still be + * prepared to split single page bios. + **/ +void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) +{ + BUG_ON(!is_power_of_2(chunk_sectors)); + q->limits.chunk_sectors = chunk_sectors; +} +EXPORT_SYMBOL(blk_queue_chunk_sectors); + +/** * blk_queue_max_discard_sectors - set max sectors for a single discard * @q: the request queue for the device * @max_discard_sectors: maximum number of sectors to discard |