[PATCH v2 10/14] udf: replace ll_rw_block()

[Zhang Yi]

ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block(). We also switch to
new bh_readahead_batch() helper for the buffer array readahead path.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/udf/dir.c       | 2 +-
 fs/udf/directory.c | 2 +-
 fs/udf/inode.c     | 8 +-------
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index cad3772f9dbe..be640f4b2f2c 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -130,7 +130,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 					brelse(tmp);
 			}
 			if (num) {
-				ll_rw_block(REQ_OP_READ | REQ_RAHEAD, num, bha);
+				bh_readahead_batch(num, bha, REQ_RAHEAD);
 				for (i = 0; i < num; i++)
 					brelse(bha[i]);
 			}
diff --git a/fs/udf/directory.c b/fs/udf/directory.c
index a2adf6293093..16bcf2c6b8b3 100644
--- a/fs/udf/directory.c
+++ b/fs/udf/directory.c
@@ -89,7 +89,7 @@ struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
 					brelse(tmp);
 			}
 			if (num) {
-				ll_rw_block(REQ_OP_READ | REQ_RAHEAD, num, bha);
+				bh_readahead_batch(num, bha, REQ_RAHEAD);
 				for (i = 0; i < num; i++)
 					brelse(bha[i]);
 			}
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 8d06daed549f..dce6ae9ae306 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1211,13 +1211,7 @@ struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
 	if (!bh)
 		return NULL;
 
-	if (buffer_uptodate(bh))
-		return bh;
-
-	ll_rw_block(REQ_OP_READ, 1, &bh);
-
-	wait_on_buffer(bh);
-	if (buffer_uptodate(bh))
+	if (bh_read(bh, 0) >= 0)
 		return bh;
 
 	brelse(bh);
-- 
2.31.1