fuse: support large folios for queued writes

Add support for folios larger than one page size for queued writes.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Bernd Schubert <bschubert@ddn.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Author: joannekoong

fs/fuse/file.c

@@ -1789,11 +1789,14 @@ __releases(fi->lock)
 __acquires(fi->lock)
 {
 	struct fuse_inode *fi = get_fuse_inode(wpa->inode);
+	struct fuse_args_pages *ap = &wpa->ia.ap;
 	struct fuse_write_in *inarg = &wpa->ia.write.in;
-	struct fuse_args *args = &wpa->ia.ap.args;
-	/* Currently, all folios in FUSE are one page */
-	__u64 data_size = wpa->ia.ap.num_folios * PAGE_SIZE;
-	int err;
+	struct fuse_args *args = &ap->args;
+	__u64 data_size = 0;
+	int err, i;
+
+	for (i = 0; i < ap->num_folios; i++)
+		data_size += ap->descs[i].length;
 
 	fi->writectr++;
 	if (inarg->offset + data_size <= size) {