fuse: convert readlink to simple api

Also turn BUG_ON into gracefully recovered WARN_ON.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 30a9609..11334ee 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1152,38 +1152,36 @@ static int fuse_permission(struct inode *inode, int mask)
 static int fuse_readlink_page(struct inode *inode, struct page *page)
 {
        struct fuse_conn *fc = get_fuse_conn(inode);
-       struct fuse_req *req;
-       int err;
+       struct fuse_page_desc desc = { .length = PAGE_SIZE - 1 };
+       struct fuse_args_pages ap = {
+               .num_pages = 1,
+               .pages = &page,
+               .descs = &desc,
+       };
+       char *link;
+       ssize_t res;
+
+       ap.args.opcode = FUSE_READLINK;
+       ap.args.nodeid = get_node_id(inode);
+       ap.args.out_pages = true;
+       ap.args.out_argvar = true;
+       ap.args.page_zeroing = true;
+       ap.args.out_numargs = 1;
+       ap.args.out_args[0].size = desc.length;
+       res = fuse_simple_request(fc, &ap.args);
 
-       req = fuse_get_req(fc, 1);
-       if (IS_ERR(req))
-               return PTR_ERR(req);
-
-       req->out.page_zeroing = 1;
-       req->out.argpages = 1;
-       req->num_pages = 1;
-       req->pages[0] = page;
-       req->page_descs[0].length = PAGE_SIZE - 1;
-       req->in.h.opcode = FUSE_READLINK;
-       req->in.h.nodeid = get_node_id(inode);
-       req->out.argvar = 1;
-       req->out.numargs = 1;
-       req->out.args[0].size = PAGE_SIZE - 1;
-       fuse_request_send(fc, req);
-       err = req->out.h.error;
+       fuse_invalidate_atime(inode);
 
-       if (!err) {
-               char *link = page_address(page);
-               size_t len = req->out.args[0].size;
+       if (res < 0)
+               return res;
 
-               BUG_ON(len >= PAGE_SIZE);
-               link[len] = '\0';
-       }
+       if (WARN_ON(res >= PAGE_SIZE))
+               return -EIO;
 
-       fuse_put_request(fc, req);
-       fuse_invalidate_atime(inode);
+       link = page_address(page);
+       link[res] = '\0';
 
-       return err;
+       return 0;
 }
 
 static const char *fuse_get_link(struct dentry *dentry, struct inode *inode,