| Message ID | 20211101203929.954622-3-willy@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iomap/xfs folio patches | expand |
On 11/1/21 2:39 PM, Matthew Wilcox (Oracle) wrote: > This is a thin wrapper around bio_add_page(). The main advantage here > is the documentation that stupidly large folios are not supported. > It's not currently possible to allocate stupidly large folios, but if > it ever becomes possible, this function will fail gracefully instead of > doing I/O to the wrong bytes. Might be better with UINT_MAX instead of stupidly here, because then it immediately makes sense. Can you make a change to that effect? With that: Reviewed-by: Jens Axboe <axboe@kernel.dk>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
On Mon, Nov 01, 2021 at 02:51:37PM -0600, Jens Axboe wrote: > On 11/1/21 2:39 PM, Matthew Wilcox (Oracle) wrote: > > This is a thin wrapper around bio_add_page(). The main advantage here > > is the documentation that stupidly large folios are not supported. > > It's not currently possible to allocate stupidly large folios, but if > > it ever becomes possible, this function will fail gracefully instead of > > doing I/O to the wrong bytes. > > Might be better with UINT_MAX instead of stupidly here, because then > it immediately makes sense. Can you make a change to that effect? I'll make it "that folios larger than 2GiB are not supported. It's not currently possible to allocate folios that large," > With that: > > Reviewed-by: Jens Axboe <axboe@kernel.dk> > > -- > Jens Axboe >
diff --git a/block/bio.c b/block/bio.c
index 15ab0d6d1c06..0e911c4fb9f2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1033,6 +1033,28 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page);
+/**
+ * bio_add_folio - Attempt to add part of a folio to a bio.
+ * @bio: BIO to add to.
+ * @folio: Folio to add.
+ * @len: How many bytes from the folio to add.
+ * @off: First byte in this folio to add.
+ *
+ * Filesystems that use folios can call this function instead of
+calling
+ * bio_add_page() for each page in the folio. If @off is bigger than
+ * PAGE_SIZE, this function can create a bio_vec that starts in a page
+ * after the bv_page. BIOs do not support folios that are 4GiB or larger.
+ *
+ * Return: Whether the addition was successful.
+ */
+bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len,
+ size_t off)
+{
+ if (len > UINT_MAX || off > UINT_MAX)
+ return 0;
+ return bio_add_page(bio, &folio->page, len, off) > 0; }
+
Newline.
On Wed, Nov 03, 2021 at 01:25:57AM +0000, wangjianjian (C) wrote: > diff --git a/block/bio.c b/block/bio.c > index 15ab0d6d1c06..0e911c4fb9f2 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -1033,6 +1033,28 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page); > > +/** > + * bio_add_folio - Attempt to add part of a folio to a bio. > + * @bio: BIO to add to. > + * @folio: Folio to add. > + * @len: How many bytes from the folio to add. > + * @off: First byte in this folio to add. > + * > + * Filesystems that use folios can call this function instead of > +calling > + * bio_add_page() for each page in the folio. If @off is bigger than > + * PAGE_SIZE, this function can create a bio_vec that starts in a page > + * after the bv_page. BIOs do not support folios that are 4GiB or larger. > + * > + * Return: Whether the addition was successful. > + */ > +bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len, > + size_t off) > +{ > + if (len > UINT_MAX || off > UINT_MAX) > + return 0; > + return bio_add_page(bio, &folio->page, len, off) > 0; } > + > > > Newline. I think it's your mail system that's mangled it. Here's how it looked to the rest of the world: https://lore.kernel.org/linux-xfs/20211101203929.954622-3-willy@infradead.org/
diff --git a/block/bio.c b/block/bio.c index 15ab0d6d1c06..0e911c4fb9f2 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1033,6 +1033,28 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page); +/** + * bio_add_folio - Attempt to add part of a folio to a bio. + * @bio: BIO to add to. + * @folio: Folio to add. + * @len: How many bytes from the folio to add. + * @off: First byte in this folio to add. + * + * Filesystems that use folios can call this function instead of calling + * bio_add_page() for each page in the folio. If @off is bigger than + * PAGE_SIZE, this function can create a bio_vec that starts in a page + * after the bv_page. BIOs do not support folios that are 4GiB or larger. + * + * Return: Whether the addition was successful. + */ +bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len, + size_t off) +{ + if (len > UINT_MAX || off > UINT_MAX) + return 0; + return bio_add_page(bio, &folio->page, len, off) > 0; +} + void __bio_release_pages(struct bio *bio, bool mark_dirty) { struct bvec_iter_all iter_all; diff --git a/include/linux/bio.h b/include/linux/bio.h index fe6bdfbbef66..a783cac49978 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -409,7 +409,8 @@ extern void bio_uninit(struct bio *); extern void bio_reset(struct bio *); void bio_chain(struct bio *, struct bio *); -extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); +int bio_add_page(struct bio *, struct page *, unsigned len, unsigned off); +bool bio_add_folio(struct bio *, struct folio *, size_t len, size_t off); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); int bio_add_zone_append_page(struct bio *bio, struct page *page,
This is a thin wrapper around bio_add_page(). The main advantage here is the documentation that stupidly large folios are not supported. It's not currently possible to allocate stupidly large folios, but if it ever becomes possible, this function will fail gracefully instead of doing I/O to the wrong bytes. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- block/bio.c | 22 ++++++++++++++++++++++ include/linux/bio.h | 3 ++- 2 files changed, 24 insertions(+), 1 deletion(-)