{
struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache,
GFP_KERNEL);
+ struct dentry *d;
if (!dcs)
return NULL;
- path->dentry->d_cookie = dcs;
+ d = path->dentry;
+ spin_lock(&d->d_lock);
+ d->d_flags |= DCACHE_COOKIE;
+ spin_unlock(&d->d_lock);
+
dcs->path = *path;
path_get(path);
hash_dcookie(dcs);
goto out;
}
- dcs = path->dentry->d_cookie;
-
- if (!dcs)
+ if (path->dentry->d_flags & DCACHE_COOKIE) {
+ dcs = find_dcookie((unsigned long)path->dentry);
+ } else {
dcs = alloc_dcookie(path);
-
- if (!dcs) {
- err = -ENOMEM;
- goto out;
+ if (!dcs) {
+ err = -ENOMEM;
+ goto out;
+ }
}
*cookie = dcookie_value(dcs);
/* And here is where the userspace process can look up the cookie value
* to retrieve the path.
*/
-asmlinkage long sys_lookup_dcookie(u64 cookie64, char __user * buf, size_t len)
+SYSCALL_DEFINE(lookup_dcookie)(u64 cookie64, char __user * buf, size_t len)
{
unsigned long cookie = (unsigned long)cookie64;
int err = -EINVAL;
mutex_unlock(&dcookie_mutex);
return err;
}
-
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_lookup_dcookie(u64 cookie64, long buf, long len)
+{
+ return SYSC_lookup_dcookie(cookie64, (char __user *) buf, (size_t) len);
+}
+SYSCALL_ALIAS(sys_lookup_dcookie, SyS_lookup_dcookie);
+#endif
static int dcookie_init(void)
{
static void free_dcookie(struct dcookie_struct * dcs)
{
- dcs->path.dentry->d_cookie = NULL;
+ struct dentry *d = dcs->path.dentry;
+
+ spin_lock(&d->d_lock);
+ d->d_flags &= ~DCACHE_COOKIE;
+ spin_unlock(&d->d_lock);
+
path_put(&dcs->path);
kmem_cache_free(dcookie_cache, dcs);
}