AFS: Don't put struct file on the stack

Don't put struct file on the stack as it takes up quite a lot of space
and violates lifetime rules for struct file.

Rather than calling afs_readpage() indirectly from the directory routines by
way of read_mapping_page(), split afs_readpage() to have afs_page_filler()
that's given a key instead of a file and call read_cache_page(), specifying the
new function directly.  Use it in afs_readpages() as well.

Also make use of this in afs_mntpt_check_symlink() too for the same reason.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index b3feddc4f7d6..a9e23039ea34 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -49,9 +49,6 @@ static unsigned long afs_mntpt_expiry_timeout = 10 * 60;
  */
 int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
 {
-        struct file file = {
-                .private_data = key,
-        };
         struct page *page;
         size_t size;
         char *buf;
@@ -61,7 +58,8 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
                vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
 
         /* read the contents of the symlink into the pagecache */
-        page = read_mapping_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0, &file);
+        page = read_cache_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0,
+                               afs_page_filler, key);
         if (IS_ERR(page)) {
                 ret = PTR_ERR(page);
                 goto out;