diff options
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index ff04e9290715..35a8f75cc45d 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -100,13 +100,14 @@ static inline bool req_gap_front_merge(struct request *req, struct bio *bio) * is defined as 'unsigned int', meantime it has to be aligned to with the * logical block size, which is the minimum accepted unit by hardware. */ -static unsigned int bio_allowed_max_sectors(struct queue_limits *lim) +static unsigned int bio_allowed_max_sectors(const struct queue_limits *lim) { return round_down(UINT_MAX, lim->logical_block_size) >> SECTOR_SHIFT; } -static struct bio *bio_split_discard(struct bio *bio, struct queue_limits *lim, - unsigned *nsegs, struct bio_set *bs) +static struct bio *bio_split_discard(struct bio *bio, + const struct queue_limits *lim, + unsigned *nsegs, struct bio_set *bs) { unsigned int max_discard_sectors, granularity; sector_t tmp; @@ -146,7 +147,8 @@ static struct bio *bio_split_discard(struct bio *bio, struct queue_limits *lim, } static struct bio *bio_split_write_zeroes(struct bio *bio, - struct queue_limits *lim, unsigned *nsegs, struct bio_set *bs) + const struct queue_limits *lim, + unsigned *nsegs, struct bio_set *bs) { *nsegs = 0; if (!lim->max_write_zeroes_sectors) @@ -165,7 +167,7 @@ static struct bio *bio_split_write_zeroes(struct bio *bio, * aligned to a physical block boundary. */ static inline unsigned get_max_io_size(struct bio *bio, - struct queue_limits *lim) + const struct queue_limits *lim) { unsigned pbs = lim->physical_block_size >> SECTOR_SHIFT; unsigned lbs = lim->logical_block_size >> SECTOR_SHIFT; @@ -184,7 +186,15 @@ static inline unsigned get_max_io_size(struct bio *bio, return max_sectors & ~(lbs - 1); } -static inline unsigned get_max_segment_size(struct queue_limits *lim, +/** + * get_max_segment_size() - maximum number of bytes to add as a single segment + * @lim: Request queue limits. + * @start_page: See below. + * @offset: Offset from @start_page where to add a segment. + * + * Returns the maximum number of bytes that can be added as a single segment. + */ +static inline unsigned get_max_segment_size(const struct queue_limits *lim, struct page *start_page, unsigned long offset) { unsigned long mask = lim->seg_boundary_mask; @@ -192,11 +202,10 @@ static inline unsigned get_max_segment_size(struct queue_limits *lim, offset = mask & (page_to_phys(start_page) + offset); /* - * overflow may be triggered in case of zero page physical address - * on 32bit arch, use queue's max segment size when that happens. + * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 + * after having calculated the minimum. */ - return min_not_zero(mask - offset + 1, - (unsigned long)lim->max_segment_size); + return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; } /** @@ -219,9 +228,9 @@ static inline unsigned get_max_segment_size(struct queue_limits *lim, * *@nsegs segments and *@sectors sectors would make that bio unacceptable for * the block driver. */ -static bool bvec_split_segs(struct queue_limits *lim, const struct bio_vec *bv, - unsigned *nsegs, unsigned *bytes, unsigned max_segs, - unsigned max_bytes) +static bool bvec_split_segs(const struct queue_limits *lim, + const struct bio_vec *bv, unsigned *nsegs, unsigned *bytes, + unsigned max_segs, unsigned max_bytes) { unsigned max_len = min(max_bytes, UINT_MAX) - *bytes; unsigned len = min(bv->bv_len, max_len); @@ -267,7 +276,7 @@ static bool bvec_split_segs(struct queue_limits *lim, const struct bio_vec *bv, * responsible for ensuring that @bs is only destroyed after processing of the * split bio has finished. */ -static struct bio *bio_split_rw(struct bio *bio, struct queue_limits *lim, +static struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim, unsigned *segs, struct bio_set *bs, unsigned max_bytes) { struct bio_vec bv, bvprv, *bvprvp = NULL; @@ -331,8 +340,9 @@ split: * The split bio is allocated from @q->bio_split, which is provided by the * block layer. */ -struct bio *__bio_split_to_limits(struct bio *bio, struct queue_limits *lim, - unsigned int *nr_segs) +struct bio *__bio_split_to_limits(struct bio *bio, + const struct queue_limits *lim, + unsigned int *nr_segs) { struct bio_set *bs = &bio->bi_bdev->bd_disk->bio_split; struct bio *split; @@ -377,7 +387,7 @@ struct bio *__bio_split_to_limits(struct bio *bio, struct queue_limits *lim, */ struct bio *bio_split_to_limits(struct bio *bio) { - struct queue_limits *lim = &bdev_get_queue(bio->bi_bdev)->limits; + const struct queue_limits *lim = &bdev_get_queue(bio->bi_bdev)->limits; unsigned int nr_segs; if (bio_may_exceed_limits(bio, lim)) |