9p: switch ->writepage() to direct use of p9_client_write()

Don't mess with kmap() - just use ITER_BVEC.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index ff1a5ba..0e153f0 100644 (file)
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -161,41 +161,32 @@ static void v9fs_invalidate_page(struct page *page, unsigned int offset,
 
 static int v9fs_vfs_writepage_locked(struct page *page)
 {
-       char *buffer;
-       int retval, len;
-       loff_t offset, size;
-       mm_segment_t old_fs;
-       struct v9fs_inode *v9inode;
        struct inode *inode = page->mapping->host;
+       struct v9fs_inode *v9inode = V9FS_I(inode);
+       loff_t size = i_size_read(inode);
+       struct iov_iter from;
+       struct bio_vec bvec;
+       int err, len;
 
-       v9inode = V9FS_I(inode);
-       size = i_size_read(inode);
        if (page->index == size >> PAGE_CACHE_SHIFT)
                len = size & ~PAGE_CACHE_MASK;
        else
                len = PAGE_CACHE_SIZE;
 
-       set_page_writeback(page);
-
-       buffer = kmap(page);
-       offset = page_offset(page);
+       bvec.bv_page = page;
+       bvec.bv_offset = 0;
+       bvec.bv_len = len;
+       iov_iter_bvec(&from, ITER_BVEC | WRITE, &bvec, 1, len);
 
-       old_fs = get_fs();
-       set_fs(get_ds());
        /* We should have writeback_fid always set */
        BUG_ON(!v9inode->writeback_fid);
 
-       retval = v9fs_file_write_internal(inode,
-                                         v9inode->writeback_fid,
-                                         (__force const char __user *)buffer,
-                                         len, &offset, 0);
-       if (retval > 0)
-               retval = 0;
+       set_page_writeback(page);
+
+       p9_client_write(v9inode->writeback_fid, page_offset(page), &from, &err);
 
-       set_fs(old_fs);
-       kunmap(page);
        end_page_writeback(page);
-       return retval;
+       return err;
 }
 
 static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)