2023-05-22 21:02:19

by David Howells

Subject: [PATCH v21 3/6] block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic

From: Christoph Hellwig <[email protected]>

Replace BIO_NO_PAGE_REF with a BIO_PAGE_REFFED flag that has the inverted
meaning is only set when a page reference has been acquired that needs to
be released by bio_release_pages().

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
cc: Al Viro <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Jan Kara <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: Logan Gunthorpe <[email protected]>
cc: [email protected]
---

Notes:
ver #8)
- Split out from another patch [hch].
- Don't default to BIO_PAGE_REFFED [hch].

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

block/bio.c | 2 +-
block/blk-map.c | 1 +
fs/direct-io.c | 2 ++
fs/iomap/direct-io.c | 1 -
include/linux/bio.h | 2 +-
include/linux/blk_types.h | 2 +-
6 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 043944fd46eb..8516adeaea26 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1191,7 +1191,6 @@ 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_set_flag(bio, BIO_CLONED);
}

@@ -1336,6 +1335,7 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
return 0;
}

+ bio_set_flag(bio, BIO_PAGE_REFFED);
do {
ret = __bio_iov_iter_get_pages(bio, iter);
} while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));
diff --git a/block/blk-map.c b/block/blk-map.c
index 04c55f1c492e..33d9f6e89ba6 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -282,6 +282,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
if (blk_queue_pci_p2pdma(rq->q))
extraction_flags |= ITER_ALLOW_P2PDMA;

+ bio_set_flag(bio, BIO_PAGE_REFFED);
while (iov_iter_count(iter)) {
struct page **pages, *stack_pages[UIO_FASTIOV];
ssize_t bytes;
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 0b380bb8a81e..ad20f3428bab 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -402,6 +402,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
bio->bi_end_io = dio_bio_end_aio;
else
bio->bi_end_io = dio_bio_end_io;
+ /* for now require references for all pages */
+ bio_set_flag(bio, BIO_PAGE_REFFED);
sdio->bio = bio;
sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
}
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 66a9f10e3207..08873f0627dd 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -203,7 +203,6 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
bio->bi_private = dio;
bio->bi_end_io = iomap_dio_bio_end_io;

- bio_set_flag(bio, BIO_NO_PAGE_REF);
__bio_add_page(bio, page, len, 0);
iomap_dio_submit_bio(iter, dio, bio, pos);
}
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 7f53be035cf0..0922729acd26 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -488,7 +488,7 @@ 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 740afe80f297..dfd2c2cb909d 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -323,7 +323,7 @@ struct bio {
* bio flags
*/
enum {
- BIO_NO_PAGE_REF, /* don't put release vec pages */
+ BIO_PAGE_REFFED, /* put pages in bio_release_pages() */
BIO_CLONED, /* doesn't own data */
BIO_BOUNCED, /* bio is a bounce bio */
BIO_QUIET, /* Make BIO Quiet */

2023-05-23 08:26:16

by Jan Kara

Subject: Re: [PATCH v21 3/6] block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic

On Mon 22-05-23 21:57:41, David Howells wrote:
> From: Christoph Hellwig <[email protected]>
>
> Replace BIO_NO_PAGE_REF with a BIO_PAGE_REFFED flag that has the inverted
> meaning is only set when a page reference has been acquired that needs to
> be released by bio_release_pages().
>
> Signed-off-by: Christoph Hellwig <[email protected]>
> Signed-off-by: David Howells <[email protected]>
> Reviewed-by: John Hubbard <[email protected]>
> cc: Al Viro <[email protected]>
> cc: Jens Axboe <[email protected]>
> cc: Jan Kara <[email protected]>
> cc: Matthew Wilcox <[email protected]>
> cc: Logan Gunthorpe <[email protected]>
> cc: [email protected]

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
>
> Notes:
> ver #8)
> - Split out from another patch [hch].
> - Don't default to BIO_PAGE_REFFED [hch].
>
> ver #5)
> - Split from patch that uses iov_iter_extract_pages().
>
> block/bio.c | 2 +-
> block/blk-map.c | 1 +
> fs/direct-io.c | 2 ++
> fs/iomap/direct-io.c | 1 -
> include/linux/bio.h | 2 +-
> include/linux/blk_types.h | 2 +-
> 6 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index 043944fd46eb..8516adeaea26 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -1191,7 +1191,6 @@ 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_set_flag(bio, BIO_CLONED);
> }
>
> @@ -1336,6 +1335,7 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
> return 0;
> }
>
> + bio_set_flag(bio, BIO_PAGE_REFFED);
> do {
> ret = __bio_iov_iter_get_pages(bio, iter);
> } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));
> diff --git a/block/blk-map.c b/block/blk-map.c
> index 04c55f1c492e..33d9f6e89ba6 100644
> --- a/block/blk-map.c
> +++ b/block/blk-map.c
> @@ -282,6 +282,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
> if (blk_queue_pci_p2pdma(rq->q))
> extraction_flags |= ITER_ALLOW_P2PDMA;
>
> + bio_set_flag(bio, BIO_PAGE_REFFED);
> while (iov_iter_count(iter)) {
> struct page **pages, *stack_pages[UIO_FASTIOV];
> ssize_t bytes;
> diff --git a/fs/direct-io.c b/fs/direct-io.c
> index 0b380bb8a81e..ad20f3428bab 100644
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -402,6 +402,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
> bio->bi_end_io = dio_bio_end_aio;
> else
> bio->bi_end_io = dio_bio_end_io;
> + /* for now require references for all pages */
> + bio_set_flag(bio, BIO_PAGE_REFFED);
> sdio->bio = bio;
> sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
> }
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 66a9f10e3207..08873f0627dd 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -203,7 +203,6 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
> bio->bi_private = dio;
> bio->bi_end_io = iomap_dio_bio_end_io;
>
> - bio_set_flag(bio, BIO_NO_PAGE_REF);
> __bio_add_page(bio, page, len, 0);
> iomap_dio_submit_bio(iter, dio, bio, pos);
> }
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 7f53be035cf0..0922729acd26 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -488,7 +488,7 @@ 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 740afe80f297..dfd2c2cb909d 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -323,7 +323,7 @@ struct bio {
> * bio flags
> */
> enum {
> - BIO_NO_PAGE_REF, /* don't put release vec pages */
> + BIO_PAGE_REFFED, /* put pages in bio_release_pages() */
> BIO_CLONED, /* doesn't own data */
> BIO_BOUNCED, /* bio is a bounce bio */
> BIO_QUIET, /* Make BIO Quiet */
>
--
Jan Kara <[email protected]>
SUSE Labs, CR