author: Junxiao Bi <junxiao.bi@oracle.com> 2013-11-21 14:31:56 -0800
committer: Linus Torvalds <torvalds@linux-foundation.org> 2013-11-21 16:42:27 -0800
commit: 76ae281f6307331aa063288edb6422ae99f435f0
parent: 527d1511310a89650000081869260394e20c7013
Commit Summary:
Diffstat:
1 file changed, 14 insertions, 2 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 4522e0755773..e081acbac2e7 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -56,10 +56,19 @@ static void configfs_d_iput(struct dentry * dentry,
struct configfs_dirent *sd = dentry->d_fsdata;
if (sd) {
- BUG_ON(sd->s_dentry != dentry);
/* Coordinate with configfs_readdir */
spin_lock(&configfs_dirent_lock);
- sd->s_dentry = NULL;
+ /* Coordinate with configfs_attach_attr where will increase
+ * sd->s_count and update sd->s_dentry to new allocated one.
+ * Only set sd->dentry to null when this dentry is the only
+ * sd owner.
+ * If not do so, configfs_d_iput may run just after
+ * configfs_attach_attr and set sd->s_dentry to null
+ * even it's still in use.
+ */
+ if (atomic_read(&sd->s_count) <= 2)
+ sd->s_dentry = NULL;
+
spin_unlock(&configfs_dirent_lock);
configfs_put(sd);
}
@@ -416,8 +425,11 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
struct configfs_attribute * attr = sd->s_element;
int error;
+ spin_lock(&configfs_dirent_lock);
dentry->d_fsdata = configfs_get(sd);
sd->s_dentry = dentry;
+ spin_unlock(&configfs_dirent_lock);
+
error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
configfs_init_file);
if (error) {