diff --git a/fs/iomap.c b/fs/iomap.c index 18f2f2b8ba2c8802585e651131cfebb8375efc89..c71a64b97fbac32bf187e374a2e5754e2f6a013a 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -881,6 +881,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, flags |= IOMAP_WRITE; } + if (iocb->ki_flags & IOCB_NOWAIT) { + if (filemap_range_has_page(mapping, start, end)) { + ret = -EAGAIN; + goto out_free_dio; + } + flags |= IOMAP_NOWAIT; + } + ret = filemap_write_and_wait_range(mapping, start, end); if (ret) goto out_free_dio; diff --git a/include/linux/iomap.h b/include/linux/iomap.h index f753e788da3109cc85cd07ac44b2f7e47fcde9b6..69f4e9470084b7e98288deb0bc45cae59bd8477f 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -52,6 +52,7 @@ struct iomap { #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ #define IOMAP_DIRECT (1 << 4) /* direct I/O */ +#define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */ struct iomap_ops { /*