diff --git a/block/fops.c b/block/fops.c index 1e970c247e0e..6c265a1bcf1b 100644 --- a/block/fops.c +++ b/block/fops.c @@ -243,6 +243,24 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, bio_endio(bio); break; } + if (iocb->ki_flags & IOCB_NOWAIT) { + /* + * This is nonblocking IO, and we need to allocate + * another bio if we have data left to map. As we + * cannot guarantee that one of the sub bios will not + * fail getting issued FOR NOWAIT and as error results + * are coalesced across all of them, be safe and ask for + * a retry of this from blocking context. + */ + if (unlikely(iov_iter_count(iter))) { + bio_release_pages(bio, false); + bio_clear_flag(bio, BIO_REFFED); + bio_put(bio); + blk_finish_plug(&plug); + return -EAGAIN; + } + bio->bi_opf |= REQ_NOWAIT; + } if (is_read) { bio->bi_opf = REQ_OP_READ; @@ -252,9 +270,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, bio->bi_opf = dio_bio_write_op(iocb); task_io_account_write(bio->bi_iter.bi_size); } - if (iocb->ki_flags & IOCB_NOWAIT) - bio->bi_opf |= REQ_NOWAIT; - dio->size += bio->bi_iter.bi_size; pos += bio->bi_iter.bi_size;