From: Christoph Hellwig Date: Mon, 23 Feb 2026 13:20:07 +0000 (-0800) Subject: block: pass a maxlen argument to bio_iov_iter_bounce X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9aa6045abde87b94168c3ba034b953417e27272;p=thirdparty%2Fkernel%2Flinux.git block: pass a maxlen argument to bio_iov_iter_bounce Allow the file system to limit the size processed in a single bounce operation. This is needed when generating integrity data so that the size of a single integrity segment can't overflow. Signed-off-by: Christoph Hellwig Reviewed-by: Anuj Gupta Reviewed-by: Kanchan Joshi Reviewed-by: Martin K. Petersen Reviewed-by: Darrick J. Wong Tested-by: Anuj Gupta Signed-off-by: Jens Axboe --- diff --git a/block/bio.c b/block/bio.c index d80d5d26804e3..784d2a66d3aef 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1327,9 +1327,10 @@ static void bio_free_folios(struct bio *bio) } } -static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter) +static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter, + size_t maxlen) { - size_t total_len = iov_iter_count(iter); + size_t total_len = min(maxlen, iov_iter_count(iter)); if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) return -EINVAL; @@ -1367,9 +1368,10 @@ static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter) return 0; } -static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter) +static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter, + size_t maxlen) { - size_t len = min(iov_iter_count(iter), SZ_1M); + size_t len = min3(iov_iter_count(iter), maxlen, SZ_1M); struct folio *folio; folio = folio_alloc_greedy(GFP_KERNEL, &len); @@ -1408,6 +1410,7 @@ static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter) * bio_iov_iter_bounce - bounce buffer data from an iter into a bio * @bio: bio to send * @iter: iter to read from / write into + * @maxlen: maximum size to bounce * * Helper for direct I/O implementations that need to bounce buffer because * we need to checksum the data or perform other operations that require @@ -1415,11 +1418,11 @@ static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter) * copies the data into it. Needs to be paired with bio_iov_iter_unbounce() * called on completion. */ -int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter) +int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter, size_t maxlen) { if (op_is_write(bio_op(bio))) - return bio_iov_iter_bounce_write(bio, iter); - return bio_iov_iter_bounce_read(bio, iter); + return bio_iov_iter_bounce_write(bio, iter, maxlen); + return bio_iov_iter_bounce_read(bio, iter, maxlen); } static void bvec_unpin(struct bio_vec *bv, bool mark_dirty) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 95254aa1b6546..21d4fad2eeb8f 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -338,7 +338,7 @@ static ssize_t iomap_dio_bio_iter_one(struct iomap_iter *iter, bio->bi_end_io = iomap_dio_bio_end_io; if (dio->flags & IOMAP_DIO_BOUNCE) - ret = bio_iov_iter_bounce(bio, dio->submit.iter); + ret = bio_iov_iter_bounce(bio, dio->submit.iter, BIO_MAX_SIZE); else ret = bio_iov_iter_get_pages(bio, dio->submit.iter, alignment - 1); diff --git a/include/linux/bio.h b/include/linux/bio.h index 36a3f2275ecd0..9693a0d6fefec 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -474,7 +474,7 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); -int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter); +int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter, size_t maxlen); void bio_iov_iter_unbounce(struct bio *bio, bool is_error, bool mark_dirty); extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,