#include <linux/errno.h>
#include <linux/dcookies.h>
#include <linux/mutex.h>
+#include <linux/path.h>
#include <asm/uaccess.h>
/* The dcookies are allocated from a kmem_cache and
* code here is particularly performance critical
*/
struct dcookie_struct {
- struct dentry * dentry;
- struct vfsmount * vfsmnt;
+ struct path path;
struct list_head hash_list;
};
/* The dentry is locked, its address will do for the cookie */
static inline unsigned long dcookie_value(struct dcookie_struct * dcs)
{
- return (unsigned long)dcs->dentry;
+ return (unsigned long)dcs->path.dentry;
}
}
-static struct dcookie_struct * alloc_dcookie(struct dentry * dentry,
- struct vfsmount * vfsmnt)
+static struct dcookie_struct *alloc_dcookie(struct path *path)
{
- struct dcookie_struct * dcs = kmem_cache_alloc(dcookie_cache, GFP_KERNEL);
+ struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache,
+ GFP_KERNEL);
+ struct dentry *d;
if (!dcs)
return NULL;
- dentry->d_cookie = dcs;
+ d = path->dentry;
+ spin_lock(&d->d_lock);
+ d->d_flags |= DCACHE_COOKIE;
+ spin_unlock(&d->d_lock);
- dcs->dentry = dget(dentry);
- dcs->vfsmnt = mntget(vfsmnt);
+ dcs->path = *path;
+ path_get(path);
hash_dcookie(dcs);
-
return dcs;
}
/* This is the main kernel-side routine that retrieves the cookie
* value for a dentry/vfsmnt pair.
*/
-int get_dcookie(struct dentry * dentry, struct vfsmount * vfsmnt,
- unsigned long * cookie)
+int get_dcookie(struct path *path, unsigned long *cookie)
{
int err = 0;
struct dcookie_struct * dcs;
goto out;
}
- dcs = dentry->d_cookie;
-
- if (!dcs)
- dcs = alloc_dcookie(dentry, vfsmnt);
-
- if (!dcs) {
- err = -ENOMEM;
- goto out;
+ 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;
+ }
}
*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;
goto out;
/* FIXME: (deleted) ? */
- path = d_path(dcs->dentry, dcs->vfsmnt, kbuf, PAGE_SIZE);
+ path = d_path(&dcs->path, kbuf, PAGE_SIZE);
if (IS_ERR(path)) {
err = PTR_ERR(path);
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->dentry->d_cookie = NULL;
- dput(dcs->dentry);
- mntput(dcs->vfsmnt);
+ 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);
}