[PATCH v5 7/9] bio: Rename BIO_NO_PAGE_REF to BIO_PAGE_REFFED and invert the meaning

David Howells
2023-01-11T14:34:32Z

Rename BIO_NO_PAGE_REF to BIO_PAGE_REFFED and invert the meaning. In a
following patch I intend to add a BIO_PAGE_PINNED flag to indicate that the
page needs unpinning and this way both flags have the same logic.

Changes
=======
ver #5)
- Split from patch that uses iov_iter_extract_pages().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Jan Kara <jack@suse.cz>
cc: Christoph Hellwig <hch@lst.de>
cc: Matthew Wilcox <willy@infradead.org>
cc: Logan Gunthorpe <logang@deltatee.com>
cc: linux-block@vger.kernel.org
Link: https://lore.kernel.org/r/167305166150.1521586.10220949115402059720.stgit@warthog.procyon.org.uk/ # v4
---

block/bio.c | 9 ++++++++-
include/linux/bio.h | 2 +-
include/linux/blk_types.h | 2 +-
3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 5f96fcae3f75..0fa140789d16 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -243,6 +243,10 @@ static void bio_free(struct bio *bio)
* Users of this function have their own bio allocation. Subsequently,
* they must remember to pair any call to bio_init() with bio_uninit()
* when IO has completed, or when the bio is released.
+ *
+ * We set the initial assumption that pages attached to the bio will be
+ * released with put_page() by setting BIO_PAGE_REFFED; if the pages
+ * should not be put, this flag should be cleared.
*/
void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
unsigned short max_vecs, blk_opf_t opf)
@@ -274,6 +278,7 @@ void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
#ifdef CONFIG_BLK_DEV_INTEGRITY
bio->bi_integrity = NULL;
#endif
+ bio_set_flag(bio, BIO_PAGE_REFFED);
bio->bi_vcnt = 0;

atomic_set(&bio->__bi_remaining, 1);
@@ -302,6 +307,7 @@ void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf)
{
bio_uninit(bio);
memset(bio, 0, BIO_RESET_BYTES);
+ bio_set_flag(bio, BIO_PAGE_REFFED);
atomic_set(&bio->__bi_remaining, 1);
bio->bi_bdev = bdev;
if (bio->bi_bdev)
@@ -812,6 +818,7 @@ EXPORT_SYMBOL(bio_put);
static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
{
bio_set_flag(bio, BIO_CLONED);
+ bio_clear_flag(bio, BIO_PAGE_REFFED);
bio->bi_ioprio = bio_src->bi_ioprio;
bio->bi_iter = bio_src->bi_iter;

@@ -1198,7 +1205,7 @@ void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter)
bio->bi_io_vec = (struct bio_vec *)iter->bvec;
bio->bi_iter.bi_bvec_done = iter->iov_offset;
bio->bi_iter.bi_size = size;
- bio_set_flag(bio, BIO_NO_PAGE_REF);
+ bio_clear_flag(bio, BIO_PAGE_REFFED);
bio_set_flag(bio, BIO_CLONED);
}

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 22078a28d7cb..63bfd91793f9 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -482,7 +482,7 @@ void zero_fill_bio(struct bio *bio);

static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
{
- if (!bio_flagged(bio, BIO_NO_PAGE_REF))
+ if (bio_flagged(bio, BIO_PAGE_REFFED))
__bio_release_pages(bio, mark_dirty);
}

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 99be590f952f..2f64b3606397 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -318,7 +318,7 @@ struct bio {
* bio flags
*/
enum {
- BIO_NO_PAGE_REF, /* don't put release vec pages */
+ BIO_PAGE_REFFED, /* Pages need refs putting (see FOLL_GET) */
BIO_CLONED, /* doesn't own data */
BIO_BOUNCED, /* bio is a bounce bio */
BIO_QUIET, /* Make BIO Quiet */