All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-mm@kvack.org, linux-block@vger.kernel.org
Subject: [PATCH v15 02/17] block: Add bio_for_each_folio_all()
Date: Mon, 19 Jul 2021 19:39:46 +0100	[thread overview]
Message-ID: <20210719184001.1750630-3-willy@infradead.org> (raw)
In-Reply-To: <20210719184001.1750630-1-willy@infradead.org>

Allow callers to iterate over each folio instead of each page.  The
bio need not have been constructed using folios originally.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 Documentation/core-api/kernel-api.rst |  1 +
 include/linux/bio.h                   | 53 ++++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst
index 2a7444e3a4c2..b804605f705e 100644
--- a/Documentation/core-api/kernel-api.rst
+++ b/Documentation/core-api/kernel-api.rst
@@ -279,6 +279,7 @@ Accounting Framework
 Block Devices
 =============
 
+.. kernel-doc:: include/linux/bio.h
 .. kernel-doc:: block/blk-core.c
    :export:
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ade93e2de6a1..a90a79ad7bd1 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -189,7 +189,7 @@ static inline void bio_advance_iter_single(const struct bio *bio,
  */
 #define bio_for_each_bvec_all(bvl, bio, i)		\
 	for (i = 0, bvl = bio_first_bvec_all(bio);	\
-	     i < (bio)->bi_vcnt; i++, bvl++)		\
+	     i < (bio)->bi_vcnt; i++, bvl++)
 
 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
 
@@ -314,6 +314,57 @@ static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
 	return &bio->bi_io_vec[bio->bi_vcnt - 1];
 }
 
+/**
+ * struct folio_iter - State for iterating all folios in a bio.
+ * @folio: The current folio we're iterating.  NULL after the last folio.
+ * @offset: The byte offset within the current folio.
+ * @length: The number of bytes in this iteration (will not cross folio
+ *	boundary).
+ */
+struct folio_iter {
+	struct folio *folio;
+	size_t offset;
+	size_t length;
+	/* private: for use by the iterator */
+	size_t _seg_count;
+	int _i;
+};
+
+static inline
+void bio_first_folio(struct folio_iter *fi, struct bio *bio, int i)
+{
+	struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
+
+	fi->folio = page_folio(bvec->bv_page);
+	fi->offset = bvec->bv_offset +
+			PAGE_SIZE * (bvec->bv_page - &fi->folio->page);
+	fi->_seg_count = bvec->bv_len;
+	fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
+	fi->_i = i;
+}
+
+static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
+{
+	fi->_seg_count -= fi->length;
+	if (fi->_seg_count) {
+		fi->folio = folio_next(fi->folio);
+		fi->offset = 0;
+		fi->length = min(folio_size(fi->folio), fi->_seg_count);
+	} else if (fi->_i + 1 < bio->bi_vcnt) {
+		bio_first_folio(fi, bio, fi->_i + 1);
+	} else {
+		fi->folio = NULL;
+	}
+}
+
+/**
+ * bio_for_each_folio_all - Iterate over each folio in a bio.
+ * @fi: struct folio_iter which is updated for each folio.
+ * @bio: struct bio to iterate over.
+ */
+#define bio_for_each_folio_all(fi, bio)				\
+	for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))
+
 enum bip_flags {
 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
-- 
2.30.2


  parent reply	other threads:[~2021-07-19 22:08 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-19 18:39 [PATCH v15 00/17] Folio support in block + iomap layers Matthew Wilcox (Oracle)
2021-07-19 18:39 ` [PATCH v15 01/17] block: Add bio_add_folio() Matthew Wilcox (Oracle)
2021-07-20  1:28   ` Darrick J. Wong
2021-07-20  6:42   ` Christoph Hellwig
2021-07-20 11:16     ` Matthew Wilcox
2021-07-22 16:27     ` Matthew Wilcox
2021-07-30  8:25   ` Ming Lei
2021-07-30 11:30     ` Matthew Wilcox
2021-07-19 18:39 ` Matthew Wilcox (Oracle) [this message]
2021-07-20  1:29   ` [PATCH v15 02/17] block: Add bio_for_each_folio_all() Darrick J. Wong
2021-07-20  1:59     ` Matthew Wilcox
2021-07-20  6:48   ` Christoph Hellwig
2021-07-23  2:40     ` Matthew Wilcox
2021-07-20 12:05   ` kernel test robot
2021-07-20 12:05   ` kernel test robot
2021-07-20 12:26   ` kernel test robot
2021-07-19 18:39 ` [PATCH v15 03/17] iomap: Convert to_iomap_page to take a folio Matthew Wilcox (Oracle)
2021-07-20  6:49   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 04/17] iomap: Convert iomap_page_create " Matthew Wilcox (Oracle)
2021-07-20  6:50   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 05/17] iomap: Convert iomap_page_release " Matthew Wilcox (Oracle)
2021-07-20  6:52   ` Christoph Hellwig
2021-07-20 11:29     ` Matthew Wilcox
2021-07-20 11:40       ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 06/17] iomap: Convert iomap_releasepage to use " Matthew Wilcox (Oracle)
2021-07-20  6:54   ` Christoph Hellwig
2021-07-20 23:56   ` Darrick J. Wong
2021-07-19 18:39 ` [PATCH v15 07/17] iomap: Convert iomap_invalidatepage " Matthew Wilcox (Oracle)
2021-07-20  6:55   ` Christoph Hellwig
2021-07-20 23:57   ` Darrick J. Wong
2021-07-19 18:39 ` [PATCH v15 08/17] iomap: Pass the iomap_page into iomap_set_range_uptodate Matthew Wilcox (Oracle)
2021-07-20  6:57   ` Christoph Hellwig
2021-07-20 11:36     ` Matthew Wilcox
2021-07-19 18:39 ` [PATCH v15 09/17] iomap: Use folio offsets instead of page offsets Matthew Wilcox (Oracle)
2021-07-20  6:59   ` Christoph Hellwig
2021-07-20 11:42     ` Matthew Wilcox
2021-07-19 18:39 ` [PATCH v15 10/17] iomap: Convert bio completions to use folios Matthew Wilcox (Oracle)
2021-07-20  7:08   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 11/17] iomap: Convert readahead and readpage to use a folio Matthew Wilcox (Oracle)
2021-07-20  7:09   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 12/17] iomap: Convert iomap_page_mkwrite " Matthew Wilcox (Oracle)
2021-07-20  7:13   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 13/17] iomap: Convert iomap_write_begin and iomap_write_end to folios Matthew Wilcox (Oracle)
2021-07-20  7:15   ` Christoph Hellwig
2021-07-20 23:59   ` Darrick J. Wong
2021-07-19 18:39 ` [PATCH v15 14/17] iomap: Convert iomap_read_inline_data to take a folio Matthew Wilcox (Oracle)
2021-07-20  7:16   ` Christoph Hellwig
2021-07-19 18:39 ` [PATCH v15 15/17] iomap: Convert iomap_write_end_inline " Matthew Wilcox (Oracle)
2021-07-20  7:17   ` Christoph Hellwig
2021-07-19 18:40 ` [PATCH v15 16/17] iomap: Convert iomap_add_to_ioend " Matthew Wilcox (Oracle)
2021-07-20  7:20   ` Christoph Hellwig
2021-07-20 11:45     ` Matthew Wilcox
2021-07-21  0:12   ` Darrick J. Wong
2021-07-21  4:27     ` Christoph Hellwig
2021-07-21  4:31       ` Matthew Wilcox
2021-07-21 15:28         ` Darrick J. Wong
2021-07-19 18:40 ` [PATCH v15 17/17] iomap: Convert iomap_migrate_page to use folios Matthew Wilcox (Oracle)
2021-07-20  7:21   ` Christoph Hellwig
2021-07-20 13:30   ` kernel test robot
2021-07-21  0:02   ` Darrick J. Wong
2021-07-20  8:44 ` [PATCH v15 00/17] Folio support in block + iomap layers Christoph Hellwig
2021-07-20 11:08   ` Matthew Wilcox

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210719184001.1750630-3-willy@infradead.org \
    --to=willy@infradead.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --subject='Re: [PATCH v15 02/17] block: Add bio_for_each_folio_all()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.