bcache creates large bios internally, and then splits them according to the device requirements before it sends them down. If a lower level device tries to clone the bio, and the original bio had more than BIO_MAX_PAGES, the clone will fail unecessarily. We can fix this by only cloning the bio vecs that are actually in use. Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx> Change-Id: I71971827a623ce90626fa4a09b07f95f875ad890 --- drivers/block/rbd.c | 2 +- drivers/md/dm.c | 5 ++--- fs/bio.c | 13 +++++++------ 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 11777b4..c1f8a8fe 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -729,7 +729,7 @@ static struct bio *bio_chain_clone(struct bio **old, struct bio **next, } while (old_chain && (total < len)) { - tmp = bio_kmalloc(gfpmask, old_chain->bi_max_vecs); + tmp = bio_kmalloc(gfpmask, bio_segments(old_chain)); if (!tmp) goto err_out; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3f3c26e..193fb19 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1057,11 +1057,10 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector, { struct bio *clone; - clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); + clone = bio_alloc_bioset(GFP_NOIO, bv_count, bs); __bio_clone(clone, bio); clone->bi_sector = sector; - clone->bi_idx = idx; - clone->bi_vcnt = idx + bv_count; + clone->bi_vcnt = bv_count; clone->bi_size = to_bytes(len); clone->bi_flags &= ~(1 << BIO_SEG_VALID); diff --git a/fs/bio.c b/fs/bio.c index a62b5b6..a85239f 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -441,8 +441,9 @@ EXPORT_SYMBOL(bio_phys_segments); */ void __bio_clone(struct bio *bio, struct bio *bio_src) { - memcpy(bio->bi_io_vec, bio_src->bi_io_vec, - bio_src->bi_max_vecs * sizeof(struct bio_vec)); + memcpy(bio->bi_io_vec, + bio_iovec(bio_src), + bio_segments(bio_src) * sizeof(struct bio_vec)); /* * most users will be overriding ->bi_bdev with a new target, @@ -451,10 +452,10 @@ void __bio_clone(struct bio *bio, struct bio *bio_src) bio->bi_sector = bio_src->bi_sector; bio->bi_bdev = bio_src->bi_bdev; bio->bi_flags |= 1 << BIO_CLONED; + bio->bi_flags &= ~(1 << BIO_SEG_VALID); bio->bi_rw = bio_src->bi_rw; - bio->bi_vcnt = bio_src->bi_vcnt; + bio->bi_vcnt = bio_segments(bio_src); bio->bi_size = bio_src->bi_size; - bio->bi_idx = bio_src->bi_idx; } EXPORT_SYMBOL(__bio_clone); @@ -469,7 +470,7 @@ EXPORT_SYMBOL(__bio_clone); struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) { - struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bs); + struct bio *b = bio_alloc_bioset(gfp_mask, bio_segments(bio), bs); if (!b) return NULL; @@ -499,7 +500,7 @@ EXPORT_SYMBOL(bio_clone); struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) { - struct bio *b = bio_kmalloc(gfp_mask, bio->bi_max_vecs); + struct bio *b = bio_kmalloc(gfp_mask, bio_segments(bio)); if (!b) return NULL; -- 1.7.9.3.327.g2980b -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel