[PATCH 3.4 011/125] FS-Cache: Increase reference of parent after registering, netfs success

[lizf]

From: Kinglong Mee <kinglong...@gmail.com>

3.4.113-rc1 review patch.  If anyone has any objections, please let me know.

------------------


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 <kinglong...@gmail.com>
Signed-off-by: David Howells <dhowe...@redhat.com>
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Zefan Li <lize...@huawei.com>
---
 fs/fscache/netfs.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index e028b8e..0912b90 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -45,9 +45,6 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
        netfs->primary_index->parent            = &fscache_fsdef_index;
        netfs->primary_index->netfs_data        = netfs;
 
-       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);
 
@@ -60,6 +57,9 @@ 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;
 
@@ -70,8 +70,7 @@ 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;
        }
 
-- 
1.9.1