vfs: new d_init method

Allow filesystem to initialize dentry at allocation time.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index d5beef01cdfc..6d60a764c848 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1569,6 +1569,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
 {
         struct dentry *dentry;
         char *dname;
+        int err;
 
         dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
         if (!dentry)
@@ -1627,6 +1628,16 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
         INIT_LIST_HEAD(&dentry->d_child);
         d_set_d_op(dentry, dentry->d_sb->s_d_op);
 
+        if (dentry->d_op && dentry->d_op->d_init) {
+                err = dentry->d_op->d_init(dentry);
+                if (err) {
+                        if (dname_external(dentry))
+                                kfree(external_name(dentry));
+                        kmem_cache_free(dentry_cache, dentry);
+                        return NULL;
+                }
+        }
+
         this_cpu_inc(nr_dentry);
 
         return dentry;