bcachefs: Use bio_iov_vecs_to_alloc()

This fixes a bug in the DIO read path where, when using a loopback
device in DIO mode, we'd allocate a biovec that would get overwritten
and leaked in bio_iov_iter_get_pages() -> bio_iov_bvec_set().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-03-08 13:52:58 -05:00 committed by Kent Overstreet
parent 590b91cf3f
commit 4d126dc8b3

View File

@ -1889,7 +1889,7 @@ static int bch2_direct_IO_read(struct kiocb *req, struct iov_iter *iter)
iter->count -= shorten;
bio = bio_alloc_bioset(NULL,
iov_iter_npages(iter, BIO_MAX_VECS),
bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS),
REQ_OP_READ,
GFP_KERNEL,
&c->dio_read_bioset);
@ -1926,7 +1926,7 @@ static int bch2_direct_IO_read(struct kiocb *req, struct iov_iter *iter)
goto start;
while (iter->count) {
bio = bio_alloc_bioset(NULL,
iov_iter_npages(iter, BIO_MAX_VECS),
bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS),
REQ_OP_READ,
GFP_KERNEL,
&c->bio_read);
@ -2297,9 +2297,7 @@ ssize_t bch2_direct_write(struct kiocb *req, struct iov_iter *iter)
}
bio = bio_alloc_bioset(NULL,
iov_iter_is_bvec(iter)
? 0
: iov_iter_npages(iter, BIO_MAX_VECS),
bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS),
REQ_OP_WRITE,
GFP_KERNEL,
&c->dio_write_bioset);