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| author | Jianyu Zhan <nasa4836@gmail.com> | 2014-04-17 17:52:10 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-04-25 12:25:13 -0700 |
| commit | c1befb885939cdaaf420c10bbe9ff57aa00446ea (patch) | |
| tree | e46f5797e3b17838b41f874f70facaf7b52bfea5 | |
| parent | a798c10faf62a505d24e5f6213fbaf904a39623f (diff) | |
| download | linux-stable-c1befb885939cdaaf420c10bbe9ff57aa00446ea.tar.gz linux-stable-c1befb885939cdaaf420c10bbe9ff57aa00446ea.tar.bz2 linux-stable-c1befb885939cdaaf420c10bbe9ff57aa00446ea.zip | |
kernfs: fix a subdir count leak
Currently kernfs_link_sibling() increates parent->dir.subdirs before
adding the node into parent's chidren rb tree.
Because it is possible that kernfs_link_sibling() couldn't find
a suitable slot and bail out, this leads to a mismatch between
elevated subdir count with actual children node numbers.
This patches fix this problem, by moving the subdir accouting
after the actual addtion happening.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/kernfs/dir.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 78f3403300af..ac127cd008bf 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -232,9 +232,6 @@ static int kernfs_link_sibling(struct kernfs_node *kn) struct rb_node **node = &kn->parent->dir.children.rb_node; struct rb_node *parent = NULL; - if (kernfs_type(kn) == KERNFS_DIR) - kn->parent->dir.subdirs++; - while (*node) { struct kernfs_node *pos; int result; @@ -249,9 +246,15 @@ static int kernfs_link_sibling(struct kernfs_node *kn) else return -EEXIST; } + /* add new node and rebalance the tree */ rb_link_node(&kn->rb, parent, node); rb_insert_color(&kn->rb, &kn->parent->dir.children); + + /* successfully added, account subdir number */ + if (kernfs_type(kn) == KERNFS_DIR) + kn->parent->dir.subdirs++; + return 0; } |