block_dev: propagate bio_iov_iter_get_pages error in __blkdev_direct_IO

Once we move the block layer to its own status code we'll still want to
propagate the bio_iov_iter_get_pages, so restructure __blkdev_direct_IO
to take ret into account when returning the errno.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 519599d..c1dc393 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -334,7 +334,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
        bool is_read = (iov_iter_rw(iter) == READ), is_sync;
        loff_t pos = iocb->ki_pos;
        blk_qc_t qc = BLK_QC_T_NONE;
-       int ret;
+       int ret = 0;
 
        if ((pos | iov_iter_alignment(iter)) &
            (bdev_logical_block_size(bdev) - 1))
@@ -363,7 +363,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 
                ret = bio_iov_iter_get_pages(bio, iter);
                if (unlikely(ret)) {
-                       bio->bi_error = ret;
+                       bio->bi_error = -EIO;
                        bio_endio(bio);
                        break;
                }
@@ -412,7 +412,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
        }
        __set_current_state(TASK_RUNNING);
 
-       ret = dio->bio.bi_error;
+       if (!ret)
+               ret = dio->bio.bi_error;
        if (likely(!ret))
                ret = dio->size;