linux-kernel - [PATCH 6/8] block: move guard_bio

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Date:   Wed, 25 Mar 2020 12:03:36 +0100
From:   Christoph Hellwig <hch@....de>
To:     Jens Axboe <axboe@...nel.dk>
Cc:     linux-block@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 6/8] block: move guard_bio_eod to bio.c

This is bio layer functionality and not related to buffer heads.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 block/bio.c         | 43 +++++++++++++++++++++++++++++++++++++++++++
 fs/buffer.c         | 43 -------------------------------------------
 fs/internal.h       |  1 -
 include/linux/bio.h |  1 +
 4 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 209715765a7a..28d8055c04e2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -588,6 +588,49 @@ void bio_truncate(struct bio *bio, unsigned new_size)
 	bio->bi_iter.bi_size = new_size;
 }
 
+/**
+ * guard_bio_eod - truncate a BIO to fit the block device
+ * @bio:	bio to truncate
+ *
+ * This allows us to do IO even on the odd last sectors of a device, even if the
+ * block size is some multiple of the physical sector size.
+ *
+ * We'll just truncate the bio to the size of the device, and clear the end of
+ * the buffer head manually.  Truly out-of-range accesses will turn into actual
+ * I/O errors, this only handles the "we need to be able to do I/O at the final
+ * sector" case.
+ */
+void guard_bio_eod(struct bio *bio)
+{
+	sector_t maxsector;
+	struct hd_struct *part;
+
+	rcu_read_lock();
+	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	if (part)
+		maxsector = part_nr_sects_read(part);
+	else
+		maxsector = get_capacity(bio->bi_disk);
+	rcu_read_unlock();
+
+	if (!maxsector)
+		return;
+
+	/*
+	 * If the *whole* IO is past the end of the device,
+	 * let it through, and the IO layer will turn it into
+	 * an EIO.
+	 */
+	if (unlikely(bio->bi_iter.bi_sector >= maxsector))
+		return;
+
+	maxsector -= bio->bi_iter.bi_sector;
+	if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
+		return;
+
+	bio_truncate(bio, maxsector << 9);
+}
+
 /**
  * bio_put - release a reference to a bio
  * @bio:   bio to release reference to
diff --git a/fs/buffer.c b/fs/buffer.c
index b8d28370cfd7..3f5758e01e40 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3019,49 +3019,6 @@ static void end_bio_bh_io_sync(struct bio *bio)
 	bio_put(bio);
 }
 
-/*
- * This allows us to do IO even on the odd last sectors
- * of a device, even if the block size is some multiple
- * of the physical sector size.
- *
- * We'll just truncate the bio to the size of the device,
- * and clear the end of the buffer head manually.
- *
- * Truly out-of-range accesses will turn into actual IO
- * errors, this only handles the "we need to be able to
- * do IO at the final sector" case.
- */
-void guard_bio_eod(struct bio *bio)
-{
-	sector_t maxsector;
-	struct hd_struct *part;
-
-	rcu_read_lock();
-	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
-	if (part)
-		maxsector = part_nr_sects_read(part);
-	else
-		maxsector = get_capacity(bio->bi_disk);
-	rcu_read_unlock();
-
-	if (!maxsector)
-		return;
-
-	/*
-	 * If the *whole* IO is past the end of the device,
-	 * let it through, and the IO layer will turn it into
-	 * an EIO.
-	 */
-	if (unlikely(bio->bi_iter.bi_sector >= maxsector))
-		return;
-
-	maxsector -= bio->bi_iter.bi_sector;
-	if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
-		return;
-
-	bio_truncate(bio, maxsector << 9);
-}
-
 static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
 			 enum rw_hint write_hint, struct writeback_control *wbc)
 {
diff --git a/fs/internal.h b/fs/internal.h
index f3f280b952a3..4d37912a5587 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -38,7 +38,6 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait)
 /*
  * buffer.c
  */
-extern void guard_bio_eod(struct bio *bio);
 extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block, struct iomap *iomap);
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 853d92ceee64..a430e9c1c2d2 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -471,6 +471,7 @@ extern struct bio *bio_copy_user_iov(struct request_queue *,
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
 void bio_truncate(struct bio *bio, unsigned new_size);
+void guard_bio_eod(struct bio *bio);
 
 static inline void zero_fill_bio(struct bio *bio)
 {
-- 
2.25.1