This is bio layer functionality and not related to buffer heads. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- 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 bc9152977bf0..11e6aac35092 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