/*
* Usage:
* dcache->d_inode->i_lock protects:
- * - i_dentry, d_alias, d_inode of aliases
+ * - i_dentry, d_u.d_alias, d_inode of aliases
* dcache_hash_bucket lock protects:
* - the dcache hash table
* s_anon bl list spinlock protects:
* - d_unhashed()
* - d_parent and d_subdirs
* - childrens' d_child and d_parent
- * - d_alias, d_inode
+ * - d_u.d_alias, d_inode
*
* Ordering:
* dentry->d_inode->i_lock
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
- WARN_ON(!hlist_unhashed(&dentry->d_alias));
kmem_cache_free(dentry_cache, dentry);
}
static void __d_free_external(struct rcu_head *head)
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
- WARN_ON(!hlist_unhashed(&dentry->d_alias));
kfree(external_name(dentry));
kmem_cache_free(dentry_cache, dentry);
}
static void dentry_free(struct dentry *dentry)
{
+ WARN_ON(!hlist_unhashed(&dentry->d_u.d_alias));
if (unlikely(dname_external(dentry))) {
struct external_name *p = external_name(dentry);
if (likely(atomic_dec_and_test(&p->u.count))) {
struct inode *inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
- hlist_del_init(&dentry->d_alias);
+ hlist_del_init(&dentry->d_u.d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
if (!inode->i_nlink)
struct inode *inode = dentry->d_inode;
__d_clear_type(dentry);
dentry->d_inode = NULL;
- hlist_del_init(&dentry->d_alias);
+ hlist_del_init(&dentry->d_u.d_alias);
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
}
/* if it was on the hash then remove it */
__d_drop(dentry);
- list_del(&dentry->d_u.d_child);
+ __list_del_entry(&dentry->d_child);
/*
* Inform d_walk() that we are no longer attached to the
* dentry tree
again:
discon_alias = NULL;
- hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
spin_lock(&alias->d_lock);
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
struct dentry *dentry;
restart:
spin_lock(&inode->i_lock);
- hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_lockref.count) {
struct dentry *parent = lock_parent(dentry);
resume:
while (next != &this_parent->d_subdirs) {
struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+ struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
next = tmp->next;
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
/*
* All done at this level ... ascend and resume the search.
*/
+ rcu_read_lock();
+ascend:
if (this_parent != parent) {
struct dentry *child = this_parent;
this_parent = child->d_parent;
- rcu_read_lock();
spin_unlock(&child->d_lock);
spin_lock(&this_parent->d_lock);
- /*
- * might go back up the wrong parent if we have had a rename
- * or deletion
- */
- if (this_parent != child->d_parent ||
- (child->d_flags & DCACHE_DENTRY_KILLED) ||
- need_seqretry(&rename_lock, seq)) {
- spin_unlock(&this_parent->d_lock);
- rcu_read_unlock();
+ /* might go back up the wrong parent if we have had a rename. */
+ if (need_seqretry(&rename_lock, seq))
goto rename_retry;
+ next = child->d_child.next;
+ while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)) {
+ if (next == &this_parent->d_subdirs)
+ goto ascend;
+ child = list_entry(next, struct dentry, d_child);
+ next = next->next;
}
rcu_read_unlock();
- next = child->d_u.d_child.next;
goto resume;
}
- if (need_seqretry(&rename_lock, seq)) {
- spin_unlock(&this_parent->d_lock);
+ if (need_seqretry(&rename_lock, seq))
goto rename_retry;
- }
+ rcu_read_unlock();
if (finish)
finish(data);
return;
rename_retry:
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ BUG_ON(seq & 1);
if (!retry)
return;
seq = 1;
INIT_HLIST_BL_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
- INIT_HLIST_NODE(&dentry->d_alias);
- INIT_LIST_HEAD(&dentry->d_u.d_child);
+ INIT_HLIST_NODE(&dentry->d_u.d_alias);
+ INIT_LIST_HEAD(&dentry->d_child);
d_set_d_op(dentry, dentry->d_sb->s_d_op);
this_cpu_inc(nr_dentry);
*/
__dget_dlock(parent);
dentry->d_parent = parent;
- list_add(&dentry->d_u.d_child, &parent->d_subdirs);
+ list_add(&dentry->d_child, &parent->d_subdirs);
spin_unlock(&parent->d_lock);
return dentry;
spin_lock(&dentry->d_lock);
__d_set_type(dentry, add_flags);
if (inode)
- hlist_add_head(&dentry->d_alias, &inode->i_dentry);
+ hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
dentry->d_inode = inode;
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
void d_instantiate(struct dentry *entry, struct inode * inode)
{
- BUG_ON(!hlist_unhashed(&entry->d_alias));
+ BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
if (inode)
spin_lock(&inode->i_lock);
__d_instantiate(entry, inode);
return NULL;
}
- hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
/*
* Don't need alias->d_lock here, because aliases with
* d_parent == entry->d_parent are not subject to name or
{
struct dentry *result;
- BUG_ON(!hlist_unhashed(&entry->d_alias));
+ BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
if (inode)
spin_lock(&inode->i_lock);
*/
int d_instantiate_no_diralias(struct dentry *entry, struct inode *inode)
{
- BUG_ON(!hlist_unhashed(&entry->d_alias));
+ BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
spin_lock(&inode->i_lock);
if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry)) {
if (hlist_empty(&inode->i_dentry))
return NULL;
- alias = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+ alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
__dget(alias);
return alias;
}
spin_lock(&tmp->d_lock);
tmp->d_inode = inode;
tmp->d_flags |= add_flags;
- hlist_add_head(&tmp->d_alias, &inode->i_dentry);
+ hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry);
hlist_bl_lock(&tmp->d_sb->s_anon);
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
hlist_bl_unlock(&tmp->d_sb->s_anon);
* if not go ahead and create it now.
*/
found = d_hash_and_lookup(dentry->d_parent, name);
- if (unlikely(IS_ERR(found)))
- goto err_out;
if (!found) {
new = d_alloc(dentry->d_parent, name);
if (!new) {
found = ERR_PTR(-ENOMEM);
- goto err_out;
- }
-
- found = d_splice_alias(inode, new);
- if (found) {
- dput(new);
- return found;
- }
- return new;
- }
-
- /*
- * If a matching dentry exists, and it's not negative use it.
- *
- * Decrement the reference count to balance the iget() done
- * earlier on.
- */
- if (found->d_inode) {
- if (unlikely(found->d_inode != inode)) {
- /* This can't happen because bad inodes are unhashed. */
- BUG_ON(!is_bad_inode(inode));
- BUG_ON(!is_bad_inode(found->d_inode));
+ } else {
+ found = d_splice_alias(inode, new);
+ if (found) {
+ dput(new);
+ return found;
+ }
+ return new;
}
- iput(inode);
- return found;
}
-
- /*
- * Negative dentry: instantiate it unless the inode is a directory and
- * already has a dentry.
- */
- new = d_splice_alias(inode, found);
- if (new) {
- dput(found);
- found = new;
- }
- return found;
-
-err_out:
iput(inode);
return found;
}
struct dentry *child;
spin_lock(&dparent->d_lock);
- list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
+ list_for_each_entry(child, &dparent->d_subdirs, d_child) {
if (dentry == child) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
__dget_dlock(dentry);
*/
unsigned int i;
BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long)));
+ kmemcheck_mark_initialized(dentry->d_iname, DNAME_INLINE_LEN);
+ kmemcheck_mark_initialized(target->d_iname, DNAME_INLINE_LEN);
for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) {
swap(((long *) &dentry->d_iname)[i],
((long *) &target->d_iname)[i]);
/* splicing a tree */
dentry->d_parent = target->d_parent;
target->d_parent = target;
- list_del_init(&target->d_u.d_child);
- list_move(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+ list_del_init(&target->d_child);
+ list_move(&dentry->d_child, &dentry->d_parent->d_subdirs);
} else {
/* swapping two dentries */
swap(dentry->d_parent, target->d_parent);
- list_move(&target->d_u.d_child, &target->d_parent->d_subdirs);
- list_move(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+ list_move(&target->d_child, &target->d_parent->d_subdirs);
+ list_move(&dentry->d_child, &dentry->d_parent->d_subdirs);
if (exchange)
fsnotify_d_move(target);
fsnotify_d_move(dentry);
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
*/
-static struct dentry *__d_unalias(struct inode *inode,
+static int __d_unalias(struct inode *inode,
struct dentry *dentry, struct dentry *alias)
{
struct mutex *m1 = NULL, *m2 = NULL;
- struct dentry *ret = ERR_PTR(-EBUSY);
+ int ret = -EBUSY;
/* If alias and dentry share a parent, then no extra locks required */
if (alias->d_parent == dentry->d_parent)
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
__d_move(alias, dentry, false);
- ret = alias;
+ ret = 0;
out_err:
spin_unlock(&inode->i_lock);
if (m2)
*/
struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
{
- struct dentry *new = NULL;
-
if (IS_ERR(inode))
return ERR_CAST(inode);
- if (inode && S_ISDIR(inode->i_mode)) {
- spin_lock(&inode->i_lock);
- new = __d_find_any_alias(inode);
- if (new) {
- if (!IS_ROOT(new)) {
- spin_unlock(&inode->i_lock);
- dput(new);
- iput(inode);
- return ERR_PTR(-EIO);
- }
- if (d_ancestor(new, dentry)) {
- spin_unlock(&inode->i_lock);
- dput(new);
- iput(inode);
- return ERR_PTR(-EIO);
- }
- write_seqlock(&rename_lock);
- __d_move(new, dentry, false);
- write_sequnlock(&rename_lock);
- spin_unlock(&inode->i_lock);
- security_d_instantiate(new, inode);
- iput(inode);
- } else {
- /* already taking inode->i_lock, so d_add() by hand */
- __d_instantiate(dentry, inode);
- spin_unlock(&inode->i_lock);
- security_d_instantiate(dentry, inode);
- d_rehash(dentry);
- }
- } else {
- d_instantiate(dentry, inode);
- if (d_unhashed(dentry))
- d_rehash(dentry);
- }
- return new;
-}
-EXPORT_SYMBOL(d_splice_alias);
-
-/**
- * d_materialise_unique - introduce an inode into the tree
- * @dentry: candidate dentry
- * @inode: inode to bind to the dentry, to which aliases may be attached
- *
- * Introduces an dentry into the tree, substituting an extant disconnected
- * root directory alias in its place if there is one. Caller must hold the
- * i_mutex of the parent directory.
- */
-struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
-{
- struct dentry *actual;
-
BUG_ON(!d_unhashed(dentry));
if (!inode) {
- actual = dentry;
__d_instantiate(dentry, NULL);
- d_rehash(actual);
- goto out_nolock;
+ goto out;
}
-
spin_lock(&inode->i_lock);
-
if (S_ISDIR(inode->i_mode)) {
- struct dentry *alias;
-
- /* Does an aliased dentry already exist? */
- alias = __d_find_alias(inode);
- if (alias) {
- actual = alias;
+ struct dentry *new = __d_find_any_alias(inode);
+ if (unlikely(new)) {
write_seqlock(&rename_lock);
-
- if (d_ancestor(alias, dentry)) {
- /* Check for loops */
- actual = ERR_PTR(-ELOOP);
+ if (unlikely(d_ancestor(new, dentry))) {
+ write_sequnlock(&rename_lock);
spin_unlock(&inode->i_lock);
- } else if (IS_ROOT(alias)) {
- /* Is this an anonymous mountpoint that we
- * could splice into our tree? */
- __d_move(alias, dentry, false);
+ dput(new);
+ new = ERR_PTR(-ELOOP);
+ pr_warn_ratelimited(
+ "VFS: Lookup of '%s' in %s %s"
+ " would have caused loop\n",
+ dentry->d_name.name,
+ inode->i_sb->s_type->name,
+ inode->i_sb->s_id);
+ } else if (!IS_ROOT(new)) {
+ int err = __d_unalias(inode, dentry, new);
write_sequnlock(&rename_lock);
- goto found;
+ if (err) {
+ dput(new);
+ new = ERR_PTR(err);
+ }
} else {
- /* Nope, but we must(!) avoid directory
- * aliasing. This drops inode->i_lock */
- actual = __d_unalias(inode, dentry, alias);
- }
- write_sequnlock(&rename_lock);
- if (IS_ERR(actual)) {
- if (PTR_ERR(actual) == -ELOOP)
- pr_warn_ratelimited(
- "VFS: Lookup of '%s' in %s %s"
- " would have caused loop\n",
- dentry->d_name.name,
- inode->i_sb->s_type->name,
- inode->i_sb->s_id);
- dput(alias);
+ __d_move(new, dentry, false);
+ write_sequnlock(&rename_lock);
+ spin_unlock(&inode->i_lock);
+ security_d_instantiate(new, inode);
}
- goto out_nolock;
+ iput(inode);
+ return new;
}
}
-
- /* Add a unique reference */
- actual = __d_instantiate_unique(dentry, inode);
- if (!actual)
- actual = dentry;
-
- d_rehash(actual);
-found:
+ /* already taking inode->i_lock, so d_add() by hand */
+ __d_instantiate(dentry, inode);
spin_unlock(&inode->i_lock);
-out_nolock:
- if (actual == dentry) {
- security_d_instantiate(dentry, inode);
- return NULL;
- }
-
- iput(inode);
- return actual;
+out:
+ security_d_instantiate(dentry, inode);
+ d_rehash(dentry);
+ return NULL;
}
-EXPORT_SYMBOL_GPL(d_materialise_unique);
+EXPORT_SYMBOL(d_splice_alias);
static int prepend(char **buffer, int *buflen, const char *str, int namelen)
{
{
inode_dec_link_count(inode);
BUG_ON(dentry->d_name.name != dentry->d_iname ||
- !hlist_unhashed(&dentry->d_alias) ||
+ !hlist_unhashed(&dentry->d_u.d_alias) ||
!d_unlinked(dentry));
spin_lock(&dentry->d_parent->d_lock);
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
projects / cascardo / linux.git / blobdiff