Commit e546fe1d authored by John Garry's avatar John Garry Committed by Jens Axboe
Browse files

block: Rework bio_split() return value 



Instead of returning an inconclusive value of NULL for an error in calling
bio_split(), return a ERR_PTR() always.

Also remove the BUG_ON() calls, and WARN_ON_ONCE() instead. Indeed, since
almost all callers don't check the return code from bio_split(), we'll
crash anyway (for those failures).

Fix up the only user which checks bio_split() return code today (directly
or indirectly), blk_crypto_fallback_split_bio_if_needed(). The md/bcache
code does check the return code in cached_dev_cache_miss() ->
bio_next_split() -> bio_split(), but only to see if there was a split, so
there would be no change in behaviour here (when returning a ERR_PTR()).

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarJohn Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241111112150.3756529-2-john.g.garry@oracle.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d369735e

block/bio.c

+6 −4
Original line number Diff line number Diff line
@@ -1665,16 +1665,18 @@ struct bio *bio_split(struct bio *bio, int sectors, 
{

	struct bio *split;



	BUG_ON(sectors <= 0);

	BUG_ON(sectors >= bio_sectors(bio));

	if (WARN_ON_ONCE(sectors <= 0))

		return ERR_PTR(-EINVAL);

	if (WARN_ON_ONCE(sectors >= bio_sectors(bio)))

		return ERR_PTR(-EINVAL);



	/* Zone append commands cannot be split */

	if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND))

		return NULL;

		return ERR_PTR(-EINVAL);



	split = bio_alloc_clone(bio->bi_bdev, bio, gfp, bs);

	if (!split)

		return NULL;

		return ERR_PTR(-ENOMEM);



	split->bi_iter.bi_size = sectors << 9;

block/blk-crypto-fallback.c

+1 −1
Original line number Diff line number Diff line
@@ -226,7 +226,7 @@ static bool blk_crypto_fallback_split_bio_if_needed(struct bio **bio_ptr) 


		split_bio = bio_split(bio, num_sectors, GFP_NOIO,

				      &crypto_bio_split);

		if (!split_bio) {

		if (IS_ERR(split_bio)) {

			bio->bi_status = BLK_STS_RESOURCE;

			return false;

		}