[PATCH v2 1/3] block: Export bio_discard_limit

[Luca Stefani <luca.stefani.ge1@gmail.com>]

It can be used to calculate the sector size limit of each
discard call allowing filesystem to implement their own
chunked discard logic with customized behavior, for example
cancellation due to signals.

Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com>
---
 block/blk-lib.c        | 3 ++-
 include/linux/blkdev.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 4c9f20a689f7..501cbfc4f112 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -10,7 +10,7 @@
 
 #include "blk.h"
 
-static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
+sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
 {
 	unsigned int discard_granularity = bdev_discard_granularity(bdev);
 	sector_t granularity_aligned_sector;
@@ -34,6 +34,7 @@ static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
 	 */
 	return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
 }
+EXPORT_SYMBOL(bio_discard_limit);
 
 struct bio *blk_alloc_discard_bio(struct block_device *bdev,
 		sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b7664d593486..42d63400025b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1088,6 +1088,7 @@ static inline long nr_blockdev_pages(void)
 
 extern void blk_io_schedule(void);
 
+sector_t bio_discard_limit(struct block_device *bdev, sector_t sector);
 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		sector_t nr_sects, gfp_t gfp_mask);
 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
-- 
2.46.0