* d_drop() is used mainly for stuff that wants to invalidate a dentry for some
* reason (NFS timeouts or autofs deletes).
*
- * __d_drop requires dentry->d_lock.
+ * __d_drop requires dentry->d_lock
+ * ___d_drop doesn't mark dentry as "unhashed"
+ * (dentry->d_hash.pprev will be LIST_POISON2, not NULL).
*/
-void __d_drop(struct dentry *dentry)
+static void ___d_drop(struct dentry *dentry)
{
if (!d_unhashed(dentry)) {
struct hlist_bl_head *b;
hlist_bl_lock(b);
__hlist_bl_del(&dentry->d_hash);
- dentry->d_hash.pprev = NULL;
hlist_bl_unlock(b);
/* After this call, in-progress rcu-walk path lookup will fail. */
write_seqcount_invalidate(&dentry->d_seq);
}
}
+
+void __d_drop(struct dentry *dentry)
+{
+ ___d_drop(dentry);
+ dentry->d_hash.pprev = NULL;
+}
EXPORT_SYMBOL(__d_drop);
void d_drop(struct dentry *dentry)
spin_unlock(&parent->d_lock);
goto again;
}
- rcu_read_unlock();
- if (parent != dentry)
+ if (parent != dentry) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- else
+ if (unlikely(dentry->d_lockref.count < 0)) {
+ spin_unlock(&parent->d_lock);
+ parent = NULL;
+ }
+ } else {
parent = NULL;
+ }
+ rcu_read_unlock();
return parent;
}
}
EXPORT_SYMBOL(d_instantiate);
+/*
+ * This should be equivalent to d_instantiate() + unlock_new_inode(),
+ * with lockdep-related part of unlock_new_inode() done before
+ * anything else. Use that instead of open-coding d_instantiate()/
+ * unlock_new_inode() combinations.
+ */
+void d_instantiate_new(struct dentry *entry, struct inode *inode)
+{
+ BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
+ BUG_ON(!inode);
+ lockdep_annotate_inode_mutex_key(inode);
+ security_d_instantiate(entry, inode);
+ spin_lock(&inode->i_lock);
+ __d_instantiate(entry, inode);
+ WARN_ON(!(inode->i_state & I_NEW));
+ inode->i_state &= ~I_NEW;
+ smp_mb();
+ wake_up_bit(&inode->i_state, __I_NEW);
+ spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(d_instantiate_new);
+
/**
* d_instantiate_no_diralias - instantiate a non-aliased dentry
* @entry: dentry to complete
static void __d_rehash(struct dentry *entry)
{
struct hlist_bl_head *b = d_hash(entry->d_name.hash);
- BUG_ON(!d_unhashed(entry));
+
hlist_bl_lock(b);
hlist_bl_add_head_rcu(&entry->d_hash, b);
hlist_bl_unlock(b);
retry:
rcu_read_lock();
- seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
+ seq = smp_load_acquire(&parent->d_inode->i_dir_seq);
r_seq = read_seqbegin(&rename_lock);
dentry = __d_lookup_rcu(parent, name, &d_seq);
if (unlikely(dentry)) {
rcu_read_unlock();
goto retry;
}
+
+ if (unlikely(seq & 1)) {
+ rcu_read_unlock();
+ goto retry;
+ }
+
hlist_bl_lock(b);
- if (unlikely(parent->d_inode->i_dir_seq != seq)) {
+ if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) {
hlist_bl_unlock(b);
rcu_read_unlock();
goto retry;
write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED);
/* unhash both */
- /* __d_drop does write_seqcount_barrier, but they're OK to nest. */
- __d_drop(dentry);
- __d_drop(target);
+ /* ___d_drop does write_seqcount_barrier, but they're OK to nest. */
+ ___d_drop(dentry);
+ ___d_drop(target);
/* Switch the names.. */
if (exchange)
__d_rehash(dentry);
if (exchange)
__d_rehash(target);
+ else
+ target->d_hash.pprev = NULL;
/* ... and switch them in the tree */
if (IS_ROOT(dentry)) {