1 files changed, 17 insertions, 17 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 8f05111bbb8b..44c14a87750e 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1022,7 +1022,8 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 		bh = page_buffers(page);
 		if (bh->b_size == size) {
 			end_block = init_page_buffers(page, bdev,
-						index << sizebits, size);
+						(sector_t)index << sizebits,
+						size);
 			goto done;
 		}
 		if (!try_to_free_buffers(page))
@@ -1043,7 +1044,8 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 	 */
 	spin_lock(&inode->i_mapping->private_lock);
 	link_dev_buffers(page, bh);
-	end_block = init_page_buffers(page, bdev, index << sizebits, size);
+	end_block = init_page_buffers(page, bdev, (sector_t)index << sizebits,
+			size);
 	spin_unlock(&inode->i_mapping->private_lock);
 done:
 	ret = (block < end_block) ? 1 : -ENXIO;
@@ -1251,7 +1253,7 @@ static struct buffer_head *__bread_slow(struct buffer_head *bh)
  * a local interrupt disable for that.
  */
 
-#define BH_LRU_SIZE	8
+#define BH_LRU_SIZE	16
 
 struct bh_lru {
 	struct buffer_head *bhs[BH_LRU_SIZE];
@@ -2954,7 +2956,7 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
 
 /*
  * This allows us to do IO even on the odd last sectors
- * of a device, even if the bh block size is some multiple
+ * 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,
@@ -2964,10 +2966,11 @@ 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_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
+void guard_bio_eod(int rw, struct bio *bio)
 {
 	sector_t maxsector;
-	unsigned bytes;
+	struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
+	unsigned truncated_bytes;
 
 	maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9;
 	if (!maxsector)
@@ -2982,23 +2985,20 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
 		return;
 
 	maxsector -= bio->bi_iter.bi_sector;
-	bytes = bio->bi_iter.bi_size;
-	if (likely((bytes >> 9) <= maxsector))
+	if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
 		return;
 
-	/* Uhhuh. We've got a bh that straddles the device size! */
-	bytes = maxsector << 9;
+	/* Uhhuh. We've got a bio that straddles the device size! */
+	truncated_bytes = bio->bi_iter.bi_size - (maxsector << 9);
 
 	/* Truncate the bio.. */
-	bio->bi_iter.bi_size = bytes;
-	bio->bi_io_vec[0].bv_len = bytes;
+	bio->bi_iter.bi_size -= truncated_bytes;
+	bvec->bv_len -= truncated_bytes;
 
 	/* ..and clear the end of the buffer for reads */
 	if ((rw & RW_MASK) == READ) {
-		void *kaddr = kmap_atomic(bh->b_page);
-		memset(kaddr + bh_offset(bh) + bytes, 0, bh->b_size - bytes);
-		kunmap_atomic(kaddr);
-		flush_dcache_page(bh->b_page);
+		zero_user(bvec->bv_page, bvec->bv_offset + bvec->bv_len,
+				truncated_bytes);
 	}
 }
 
@@ -3039,7 +3039,7 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
 	bio->bi_flags |= bio_flags;
 
 	/* Take care of bh's that straddle the end of the device */
-	guard_bh_eod(rw, bio, bh);
+	guard_bio_eod(rw, bio);
 
 	if (buffer_meta(bh))
 		rw |= REQ_META;