udf: replace ll_rw_block()

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.

Link: https://lkml.kernel.org/r/20220901133505.2510834-11-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index cad3772..be640f4 100644 (file)
--- 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 a2adf62..16bcf2c 100644 (file)
--- 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 8d06dae..dce6ae9 100644 (file)
--- 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);