FS-Cache: Increase reference of parent after registering, netfs success

commit 86108c2e34a26e4bec3c6ddb23390bf8cedcf391 upstream.

If netfs exist, fscache should not increase the reference of parent's
usage and n_children, otherwise, never be decreased.

v2: thanks David's suggest,
 move increasing reference of parent if success
 use kmem_cache_free() freeing primary_index directly

v3: don't move "netfs->primary_index->parent = &fscache_fsdef_index;"

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index 989f394015472bafe7758c19e006a16c57a59e4c..73e033390dee784b1dd712053aee47d3ff84bcf6 100644 (file)
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -47,9 +47,6 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
        netfs->primary_index->netfs_data        = netfs;
        netfs->primary_index->flags             = 1 << FSCACHE_COOKIE_ENABLED;
 
-       atomic_inc(&netfs->primary_index->parent->usage);
-       atomic_inc(&netfs->primary_index->parent->n_children);
-
        spin_lock_init(&netfs->primary_index->lock);
        INIT_HLIST_HEAD(&netfs->primary_index->backing_objects);
 
@@ -62,6 +59,9 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
                        goto already_registered;
        }
 
+       atomic_inc(&netfs->primary_index->parent->usage);
+       atomic_inc(&netfs->primary_index->parent->n_children);
+
        list_add(&netfs->link, &fscache_netfs_list);
        ret = 0;
 
@@ -72,8 +72,7 @@ already_registered:
        up_write(&fscache_addremove_sem);
 
        if (ret < 0) {
-               netfs->primary_index->parent = NULL;
-               __fscache_cookie_put(netfs->primary_index);
+               kmem_cache_free(fscache_cookie_jar, netfs->primary_index);
                netfs->primary_index = NULL;
        }