diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-12-04 18:34:19 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-12-15 07:34:27 -0700 |
| commit | 6ef02df154a245a4a7c0a66daa5a353daa788dba (patch) | |
| tree | d4572019dcc1ee48f3ef9ae0dd84c510c9157b32 | |
| parent | 3f034c374ad55773c12dd8f3c1607328e17c0072 (diff) | |
block: support adding less than len in bio_add_hw_page
bio_add_hw_page currently always fails or succeeds. This is fine for
the existing callers that always add PAGE_SIZE worth given that the
max_segment_size and max_sectors must always allow at least a page
worth of data. But when we want to add it for bigger amounts of data
this means it can also fail when adding the data to a bio, and creating
a fallback for that becomes really annoying in the callers.
Make use of the existing API design that allows to return a smaller
length than the one passed in and add up to max_segment_size worth
of data from a larger input. All the existing callers are fine with
this - not because they handle this return correctly, but because they
never pass more than a page in.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/bio.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/block/bio.c b/block/bio.c index 270f6b99926e..b9642a41f286 100644 --- a/block/bio.c +++ b/block/bio.c @@ -966,10 +966,13 @@ int bio_add_hw_page(struct request_queue *q, struct bio *bio, struct page *page, unsigned int len, unsigned int offset, unsigned int max_sectors, bool *same_page) { + unsigned int max_size = max_sectors << SECTOR_SHIFT; + if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) return 0; - if (((bio->bi_iter.bi_size + len) >> SECTOR_SHIFT) > max_sectors) + len = min3(len, max_size, queue_max_segment_size(q)); + if (len > max_size - bio->bi_iter.bi_size) return 0; if (bio->bi_vcnt > 0) { |