On 23.01.23 18:30, David Howells wrote:
Add BIO_PAGE_PINNED to indicate that the pages in a bio are pinned
(FOLL_PIN) and that the pin will need removing.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Jan Kara <jack@xxxxxxx>
cc: Christoph Hellwig <hch@xxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
cc: linux-block@xxxxxxxxxxxxxxx
---
Notes:
ver #8)
- Move the infrastructure to clean up pinned pages to this patch [hch].
- Put BIO_PAGE_PINNED before BIO_PAGE_REFFED as the latter should
probably be removed at some point. FOLL_PIN can then be renumbered
first.
block/bio.c | 7 ++++---
block/blk.h | 28 ++++++++++++++++++++++++++++
include/linux/bio.h | 3 ++-
include/linux/blk_types.h | 1 +
4 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 40c2b01906da..6f98bcfc0c92 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1170,13 +1170,14 @@ bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len,
void __bio_release_pages(struct bio *bio, bool mark_dirty)
{
+ unsigned int gup_flags = bio_to_gup_flags(bio);
struct bvec_iter_all iter_all;
struct bio_vec *bvec;
bio_for_each_segment_all(bvec, bio, iter_all) {
if (mark_dirty && !PageCompound(bvec->bv_page))
set_page_dirty_lock(bvec->bv_page);
- put_page(bvec->bv_page);
+ page_put_unpin(bvec->bv_page, gup_flags);
}
}
EXPORT_SYMBOL_GPL(__bio_release_pages);
@@ -1496,8 +1497,8 @@ void bio_set_pages_dirty(struct bio *bio)
* the BIO and re-dirty the pages in process context.
*
* It is expected that bio_check_pages_dirty() will wholly own the BIO from
- * here on. It will run one put_page() against each page and will run one
- * bio_put() against the BIO.
+ * here on. It will run one page_put_unpin() against each page and will run
+ * one bio_put() against the BIO.
*/
static void bio_dirty_fn(struct work_struct *work);
diff --git a/block/blk.h b/block/blk.h
index 4c3b3325219a..294044d696e0 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -425,6 +425,34 @@ int bio_add_hw_page(struct request_queue *q, struct bio *bio,
struct page *page, unsigned int len, unsigned int offset,
unsigned int max_sectors, bool *same_page);
+/*
+ * Set the cleanup mode for a bio from an iterator and the extraction flags.
+ */
+static inline void bio_set_cleanup_mode(struct bio *bio, struct iov_iter *iter)
+{
+ unsigned int cleanup_mode = iov_iter_extract_mode(iter);
+
+ if (cleanup_mode & FOLL_GET)
+ bio_set_flag(bio, BIO_PAGE_REFFED);
+ if (cleanup_mode & FOLL_PIN)
+ bio_set_flag(bio, BIO_PAGE_PINNED);
Can FOLL_GET ever happen?
IOW, can't this even be
if (user_backed_iter(iter))
bio_set_flag(bio, BIO_PAGE_PINNED);
--
Thanks,
David / dhildenb
