vfs: guard end of device for mpage interface

Add guard_bio_eod() check for mpage code in order to allow 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.

Using mpage_readpages() for block device requires this guard check.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index e442a26e80f7..7bd5c4685e98 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2966,7 +2966,7 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
  * errors, this only handles the "we need to be able to
  * do IO at the final sector" case.
  */
-static void guard_bio_eod(int rw, struct bio *bio)
+void guard_bio_eod(int rw, struct bio *bio)
 {
         sector_t maxsector;
         struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];