}
EXPORT_SYMBOL(dentry_update_name_case);
-static void switch_names(struct dentry *dentry, struct dentry *target)
+static void switch_names(struct dentry *dentry, struct dentry *target,
+ bool exchange)
{
if (dname_external(target)) {
if (dname_external(dentry)) {
*/
unsigned int i;
BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long)));
+ if (!exchange) {
+ memcpy(dentry->d_iname, target->d_name.name,
+ target->d_name.len + 1);
+ dentry->d_name.hash_len = target->d_name.hash_len;
+ return;
+ }
for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) {
swap(((long *) &dentry->d_iname)[i],
((long *) &target->d_iname)[i]);
}
}
}
- swap(dentry->d_name.len, target->d_name.len);
+ swap(dentry->d_name.hash_len, target->d_name.hash_len);
}
static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target)
}
}
-static void dentry_unlock_parents_for_move(struct dentry *dentry,
- struct dentry *target)
+static void dentry_unlock_for_move(struct dentry *dentry, struct dentry *target)
{
if (target->d_parent != dentry->d_parent)
spin_unlock(&dentry->d_parent->d_lock);
if (target->d_parent != target)
spin_unlock(&target->d_parent->d_lock);
+ spin_unlock(&target->d_lock);
+ spin_unlock(&dentry->d_lock);
}
/*
* When switching names, the actual string doesn't strictly have to
* be preserved in the target - because we're dropping the target
* anyway. As such, we can just do a simple memcpy() to copy over
- * the new name before we switch.
- *
- * Note that we have to be a lot more careful about getting the hash
- * switched - we have to switch the hash value properly even if it
- * then no longer matches the actual (corrupted) string of the target.
- * The hash value has to match the hash queue that the dentry is on..
+ * the new name before we switch, unless we are going to rehash
+ * it. Note that if we *do* unhash the target, we are not allowed
+ * to rehash it without giving it a new name/hash key - whether
+ * we swap or overwrite the names here, resulting name won't match
+ * the reality in filesystem; it's only there for d_path() purposes.
+ * Note that all of this is happening under rename_lock, so the
+ * any hash lookup seeing it in the middle of manipulations will
+ * be discarded anyway. So we do not care what happens to the hash
+ * key in that case.
*/
/*
* __d_move - move a dentry
d_hash(dentry->d_parent, dentry->d_name.hash));
}
-
/* Switch the names.. */
- switch_names(dentry, target);
- swap(dentry->d_name.hash, target->d_name.hash);
+ switch_names(dentry, target, exchange);
/* ... and switch them in the tree */
if (IS_ROOT(dentry)) {
write_seqcount_end(&target->d_seq);
write_seqcount_end(&dentry->d_seq);
- dentry_unlock_parents_for_move(dentry, target);
- spin_unlock(&target->d_lock);
- spin_unlock(&dentry->d_lock);
+ dentry_unlock_for_move(dentry, target);
}
/*