diff options
| -rw-r--r-- | fs/9p/vfs_addr.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 90e38449f4b..b7f2a8e3863 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -154,10 +154,40 @@ static int v9fs_launder_page(struct page *page) return 0; } +/** + * v9fs_direct_IO - 9P address space operation for direct I/O + * @rw: direction (read or write) + * @iocb: target I/O control block + * @iov: array of vectors that define I/O buffer + * @pos: offset in file to begin the operation + * @nr_segs: size of iovec array + * + * The presence of v9fs_direct_IO() in the address space ops vector + * allowes open() O_DIRECT flags which would have failed otherwise. + * + * In the non-cached mode, we shunt off direct read and write requests before + * the VFS gets them, so this method should never be called. + * + * Direct IO is not 'yet' supported in the cached mode. Hence when + * this routine is called through generic_file_aio_read(), the read/write fails + * with an error. + * + */ +ssize_t v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, + loff_t pos, unsigned long nr_segs) +{ + P9_DPRINTK(P9_DEBUG_VFS, "v9fs_direct_IO: v9fs_direct_IO (%s) " + "off/no(%lld/%lu) EINVAL\n", + iocb->ki_filp->f_path.dentry->d_name.name, + (long long) pos, nr_segs); + + return -EINVAL; +} const struct address_space_operations v9fs_addr_operations = { .readpage = v9fs_vfs_readpage, .readpages = v9fs_vfs_readpages, .releasepage = v9fs_release_page, .invalidatepage = v9fs_invalidate_page, .launder_page = v9fs_launder_page, + .direct_IO = v9fs_direct_IO, }; |