* - d_alias, d_inode
*
* Ordering:
- * dcache_lock
- * dcache_inode_lock
- * dentry->d_lock
- * dcache_lru_lock
- * dcache_hash_lock
+ * dcache_inode_lock
+ * dentry->d_lock
+ * dcache_lru_lock
+ * dcache_hash_lock
*
* If there is an ancestor relationship:
* dentry->d_parent->...->d_parent->d_lock
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
+EXPORT_SYMBOL(rename_lock);
EXPORT_SYMBOL(dcache_inode_lock);
-EXPORT_SYMBOL(dcache_lock);
static struct kmem_cache *dentry_cache __read_mostly;
}
/*
- * no dcache_lock, please.
+ * no locks, please.
*/
static void d_free(struct dentry *dentry)
{
static void dentry_iput(struct dentry * dentry)
__releases(dentry->d_lock)
__releases(dcache_inode_lock)
- __releases(dcache_lock)
{
struct inode *inode = dentry->d_inode;
if (inode) {
list_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (!inode->i_nlink)
fsnotify_inoderemove(inode);
if (dentry->d_op && dentry->d_op->d_iput)
} else {
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
}
*
* If this is the root of the dentry tree, return NULL.
*
- * dcache_lock and d_lock and d_parent->d_lock must be held by caller, and
- * are dropped by d_kill.
+ * dentry->d_lock and parent->d_lock must be held by caller, and are dropped by
+ * d_kill.
*/
static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
__releases(dentry->d_lock)
__releases(parent->d_lock)
__releases(dcache_inode_lock)
- __releases(dcache_lock)
{
+ dentry->d_parent = NULL;
list_del(&dentry->d_u.d_child);
if (parent)
spin_unlock(&parent->d_lock);
void d_drop(struct dentry *dentry)
{
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_drop);
if (dentry->d_count == 1)
might_sleep();
spin_lock(&dentry->d_lock);
- if (IS_ROOT(dentry))
- parent = NULL;
- else
- parent = dentry->d_parent;
- if (dentry->d_count == 1) {
- if (!spin_trylock(&dcache_lock)) {
- /*
- * Something of a livelock possibility we could avoid
- * by taking dcache_lock and trying again, but we
- * want to reduce dcache_lock anyway so this will
- * get improved.
- */
-drop1:
- spin_unlock(&dentry->d_lock);
- goto repeat;
- }
- if (!spin_trylock(&dcache_inode_lock)) {
-drop2:
- spin_unlock(&dcache_lock);
- goto drop1;
- }
- if (parent && !spin_trylock(&parent->d_lock)) {
- spin_unlock(&dcache_inode_lock);
- goto drop2;
- }
- }
- dentry->d_count--;
- if (dentry->d_count) {
+ BUG_ON(!dentry->d_count);
+ if (dentry->d_count > 1) {
+ dentry->d_count--;
spin_unlock(&dentry->d_lock);
- if (parent)
- spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
return;
}
- /*
- * AV: ->d_delete() is _NOT_ allowed to block now.
- */
if (dentry->d_op && dentry->d_op->d_delete) {
if (dentry->d_op->d_delete(dentry))
- goto unhash_it;
+ goto kill_it;
}
/* Unreachable? Get rid of it */
dentry->d_flags |= DCACHE_REFERENCED;
dentry_lru_add(dentry);
- spin_unlock(&dentry->d_lock);
- if (parent)
- spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
+ dentry->d_count--;
+ spin_unlock(&dentry->d_lock);
return;
-unhash_it:
- __d_drop(dentry);
kill_it:
+ if (!spin_trylock(&dcache_inode_lock)) {
+relock:
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ goto repeat;
+ }
+ if (IS_ROOT(dentry))
+ parent = NULL;
+ else
+ parent = dentry->d_parent;
+ if (parent && !spin_trylock(&parent->d_lock)) {
+ spin_unlock(&dcache_inode_lock);
+ goto relock;
+ }
+ dentry->d_count--;
/* if dentry was on the d_lru list delete it from there */
dentry_lru_del(dentry);
+ /* if it was on the hash (d_delete case), then remove it */
+ __d_drop(dentry);
dentry = d_kill(dentry, parent);
if (dentry)
goto repeat;
/*
* If it's already been dropped, return OK.
*/
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
/*
*/
if (!list_empty(&dentry->d_subdirs)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
shrink_dcache_parent(dentry);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
}
if (dentry->d_count > 1) {
if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return -EBUSY;
}
}
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
EXPORT_SYMBOL(d_invalidate);
-/* This must be called with dcache_lock and d_lock held */
-static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
+/* This must be called with d_lock held */
+static inline void __dget_dlock(struct dentry *dentry)
{
dentry->d_count++;
- dentry_lru_del(dentry);
- return dentry;
}
-/* This should be called _only_ with dcache_lock held */
-static inline struct dentry * __dget_locked(struct dentry *dentry)
+static inline void __dget(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
- return dentry;
-}
-
-struct dentry * dget_locked_dlock(struct dentry *dentry)
-{
- return __dget_locked_dlock(dentry);
}
-struct dentry * dget_locked(struct dentry *dentry)
-{
- return __dget_locked(dentry);
-}
-EXPORT_SYMBOL(dget_locked);
-
struct dentry *dget_parent(struct dentry *dentry)
{
struct dentry *ret;
(alias->d_flags & DCACHE_DISCONNECTED)) {
discon_alias = alias;
} else if (!want_discon) {
- __dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
return alias;
}
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
(alias->d_flags & DCACHE_DISCONNECTED)) {
- __dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
return alias;
}
struct dentry *de = NULL;
if (!list_empty(&inode->i_dentry)) {
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
de = __d_find_alias(inode, 0);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
return de;
}
{
struct dentry *dentry;
restart:
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
dput(dentry);
goto restart;
}
spin_unlock(&dentry->d_lock);
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_prune_aliases);
__releases(dentry->d_lock)
__releases(parent->d_lock)
__releases(dcache_inode_lock)
- __releases(dcache_lock)
{
__d_drop(dentry);
dentry = d_kill(dentry, parent);
/*
- * Prune ancestors. Locking is simpler than in dput(),
- * because dcache_lock needs to be taken anyway.
+ * Prune ancestors.
*/
while (dentry) {
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
again:
spin_lock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
return;
}
spin_unlock(&dcache_lru_lock);
prune_one_dentry(dentry, parent);
- /* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */
- spin_lock(&dcache_lock);
+ /* dcache_inode_lock and dentry->d_lock dropped */
spin_lock(&dcache_inode_lock);
spin_lock(&dcache_lru_lock);
}
LIST_HEAD(tmp);
int cnt = *count;
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
relock:
spin_lock(&dcache_lru_lock);
list_splice(&referenced, &sb->s_dentry_lru);
spin_unlock(&dcache_lru_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
/**
if (unused == 0 || count == 0)
return;
- spin_lock(&dcache_lock);
if (count >= unused)
prune_ratio = 1;
else
if (down_read_trylock(&sb->s_umount)) {
if ((sb->s_root != NULL) &&
(!list_empty(&sb->s_dentry_lru))) {
- spin_unlock(&dcache_lock);
__shrink_dcache_sb(sb, &w_count,
DCACHE_REFERENCED);
pruned -= w_count;
- spin_lock(&dcache_lock);
}
up_read(&sb->s_umount);
}
if (p)
__put_super(p);
spin_unlock(&sb_lock);
- spin_unlock(&dcache_lock);
}
/**
{
LIST_HEAD(tmp);
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
spin_lock(&dcache_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
}
spin_unlock(&dcache_lru_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(shrink_dcache_sb);
BUG_ON(!IS_ROOT(dentry));
/* detach this root from the system */
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
dentry_lru_del(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
for (;;) {
/* descend to the first leaf in the current subtree */
/* this is a branch with children - detach all of them
* from the system in one go */
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
list_for_each_entry(loop, &dentry->d_subdirs,
d_u.d_child) {
spin_unlock(&loop->d_lock);
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
/* move to the first child */
dentry = list_entry(dentry->d_subdirs.next,
/*
* destroy the dentries attached to a superblock on unmounting
- * - we don't need to use dentry->d_lock, and only need dcache_lock when
- * removing the dentry from the system lists and hashes because:
+ * - we don't need to use dentry->d_lock because:
* - the superblock is detached from all mountings and open files, so the
* dentry trees will not be rearranged by the VFS
* - s_umount is write-locked, so the memory pressure shrinker will ignore
* Return true if the parent or its subdirectories contain
* a mount point
*/
-
int have_submounts(struct dentry *parent)
{
- struct dentry *this_parent = parent;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
+ int locked = 0;
+
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = parent;
- spin_lock(&dcache_lock);
if (d_mountpoint(parent))
goto positive;
spin_lock(&this_parent->d_lock);
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
- next = this_parent->d_u.d_child.next;
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ rcu_read_lock();
spin_unlock(&this_parent->d_lock);
- this_parent = this_parent->d_parent;
+ child = this_parent;
+ this_parent = tmp;
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 ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return 0; /* No mount points found in tree */
positive:
- spin_unlock(&dcache_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return 1;
+
+rename_retry:
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
EXPORT_SYMBOL(have_submounts);
*/
static int select_parent(struct dentry * parent)
{
- struct dentry *this_parent = parent;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
int found = 0;
+ int locked = 0;
- spin_lock(&dcache_lock);
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = parent;
spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
- BUG_ON(this_parent == dentry);
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
*/
if (this_parent != parent) {
struct dentry *tmp;
- next = this_parent->d_u.d_child.next;
+ struct dentry *child;
+
tmp = this_parent->d_parent;
+ rcu_read_lock();
spin_unlock(&this_parent->d_lock);
- BUG_ON(tmp == this_parent);
+ child = this_parent;
this_parent = tmp;
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 ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
out:
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return found;
+
+rename_retry:
+ if (found)
+ return found;
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
/**
INIT_LIST_HEAD(&dentry->d_u.d_child);
if (parent) {
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
- spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- dentry->d_parent = dget_dlock(parent);
+ /*
+ * don't need child lock because it is not subject
+ * to concurrency here
+ */
+ __dget_dlock(parent);
+ dentry->d_parent = parent;
dentry->d_sb = parent->d_sb;
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
- spin_unlock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}
this_cpu_inc(nr_dentry);
}
EXPORT_SYMBOL(d_alloc_name);
-/* the caller must hold dcache_lock */
static void __d_instantiate(struct dentry *dentry, struct inode *inode)
{
spin_lock(&dentry->d_lock);
void d_instantiate(struct dentry *entry, struct inode * inode)
{
BUG_ON(!list_empty(&entry->d_alias));
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
__d_instantiate(entry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(entry, inode);
}
EXPORT_SYMBOL(d_instantiate);
continue;
if (memcmp(qstr->name, name, len))
continue;
- dget_locked(alias);
+ __dget(alias);
return alias;
}
BUG_ON(!list_empty(&entry->d_alias));
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
result = __d_instantiate_unique(entry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (!result) {
security_d_instantiate(entry, inode);
}
tmp->d_parent = tmp; /* make sure dput doesn't croak */
- spin_lock(&dcache_lock);
+
spin_lock(&dcache_inode_lock);
res = __d_find_alias(inode, 0);
if (res) {
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
dput(tmp);
goto out_iput;
}
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
return tmp;
out_iput:
struct dentry *new = NULL;
if (inode && S_ISDIR(inode->i_mode)) {
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(new, inode);
d_move(new, dentry);
iput(inode);
} else {
- /* already taking dcache_lock, so d_add() by hand */
+ /* already taking dcache_inode_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
* Negative dentry: instantiate it unless the inode is a directory and
* already has a dentry.
*/
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
__d_instantiate(found, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
return found;
}
* reference to it, move it in place and use it.
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- dget_locked(new);
+ __dget(new);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
d_move(new, found);
iput(inode);
struct dentry * d_lookup(struct dentry * parent, struct qstr * name)
{
struct dentry * dentry = NULL;
- unsigned long seq;
+ unsigned seq;
do {
seq = read_seqbegin(&rename_lock);
{
struct dentry *child;
- spin_lock(&dcache_lock);
spin_lock(&dparent->d_lock);
list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
if (dentry == child) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dparent->d_lock);
- spin_unlock(&dcache_lock);
return 1;
}
}
spin_unlock(&dparent->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
/*
* Are we the only user?
*/
- spin_lock(&dcache_lock);
- spin_lock(&dcache_inode_lock);
+again:
spin_lock(&dentry->d_lock);
isdir = S_ISDIR(dentry->d_inode->i_mode);
if (dentry->d_count == 1) {
+ if (!spin_trylock(&dcache_inode_lock)) {
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ goto again;
+ }
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
dentry_iput(dentry);
fsnotify_nameremove(dentry, isdir);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
fsnotify_nameremove(dentry, isdir);
}
void d_rehash(struct dentry * entry)
{
- spin_lock(&dcache_lock);
spin_lock(&entry->d_lock);
spin_lock(&dcache_hash_lock);
_d_rehash(entry);
spin_unlock(&dcache_hash_lock);
spin_unlock(&entry->d_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_rehash);
BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
memcpy((unsigned char *)dentry->d_name.name, name->name, name->len);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(dentry_update_name_case);
* The hash value has to match the hash queue that the dentry is on..
*/
/*
- * d_move_locked - move a dentry
+ * d_move - move a dentry
* @dentry: entry to move
* @target: new dentry
*
* Update the dcache to reflect the move of a file name. Negative
* dcache entries should not be moved in this way.
*/
-static void d_move_locked(struct dentry * dentry, struct dentry * target)
+void d_move(struct dentry * dentry, struct dentry * target)
{
if (!dentry->d_inode)
printk(KERN_WARNING "VFS: moving negative dcache entry\n");
spin_unlock(&dentry->d_lock);
write_sequnlock(&rename_lock);
}
-
-/**
- * d_move - move a dentry
- * @dentry: entry to move
- * @target: new dentry
- *
- * Update the dcache to reflect the move of a file name. Negative
- * dcache entries should not be moved in this way.
- */
-
-void d_move(struct dentry * dentry, struct dentry * target)
-{
- spin_lock(&dcache_lock);
- d_move_locked(dentry, target);
- spin_unlock(&dcache_lock);
-}
EXPORT_SYMBOL(d_move);
/**
* This helper attempts to cope with remotely renamed directories
*
* It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex and the dcache_lock
+ * dentry->d_parent->d_inode->i_mutex and the dcache_inode_lock
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
*/
static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
- __releases(dcache_lock)
__releases(dcache_inode_lock)
{
struct mutex *m1 = NULL, *m2 = NULL;
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- d_move_locked(alias, dentry);
+ d_move(alias, dentry);
ret = alias;
out_err:
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (m2)
mutex_unlock(m2);
if (m1)
BUG_ON(!d_unhashed(dentry));
- spin_lock(&dcache_lock);
- spin_lock(&dcache_inode_lock);
-
if (!inode) {
actual = dentry;
__d_instantiate(dentry, NULL);
- goto found_lock;
+ d_rehash(actual);
+ goto out_nolock;
}
+ spin_lock(&dcache_inode_lock);
+
if (S_ISDIR(inode->i_mode)) {
struct dentry *alias;
actual = __d_instantiate_unique(dentry, inode);
if (!actual)
actual = dentry;
- else if (unlikely(!d_unhashed(actual)))
- goto shouldnt_be_hashed;
+ else
+ BUG_ON(!d_unhashed(actual));
-found_lock:
spin_lock(&actual->d_lock);
found:
spin_lock(&dcache_hash_lock);
spin_unlock(&dcache_hash_lock);
spin_unlock(&actual->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
out_nolock:
if (actual == dentry) {
security_d_instantiate(dentry, inode);
iput(inode);
return actual;
-
-shouldnt_be_hashed:
- spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
- BUG();
}
EXPORT_SYMBOL_GPL(d_materialise_unique);
* @buffer: pointer to the end of the buffer
* @buflen: pointer to buffer length
*
- * Caller holds the dcache_lock.
+ * Caller holds the rename_lock.
*
* If path is not reachable from the supplied root, then the value of
* root is changed (without modifying refcounts).
int error;
prepend(&res, &buflen, "\0", 1);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
error = prepend_path(path, root, &res, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (error)
return ERR_PTR(error);
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
tmp = root;
error = path_with_deleted(path, &tmp, &res, &buflen);
if (error)
res = ERR_PTR(error);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
path_put(&root);
return res;
}
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
tmp = root;
error = path_with_deleted(path, &tmp, &res, &buflen);
if (!error && !path_equal(&tmp, &root))
error = prepend_unreachable(&res, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
path_put(&root);
if (error)
res = ERR_PTR(error);
{
char *retval;
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
retval = __dentry_path(dentry, buf, buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
return retval;
}
char *p = NULL;
char *retval;
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
if (d_unlinked(dentry)) {
p = buf + buflen;
if (prepend(&p, &buflen, "//deleted", 10) != 0)
buflen++;
}
retval = __dentry_path(dentry, buf, buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (!IS_ERR(retval) && p)
*p = '/'; /* restore '/' overriden with '\0' */
return retval;
Elong:
- spin_unlock(&dcache_lock);
return ERR_PTR(-ENAMETOOLONG);
}
get_fs_root_and_pwd(current->fs, &root, &pwd);
error = -ENOENT;
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
if (!d_unlinked(pwd.dentry)) {
unsigned long len;
struct path tmp = root;
prepend(&cwd, &buflen, "\0", 1);
error = prepend_path(&pwd, &tmp, &cwd, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (error)
goto out;
if (copy_to_user(buf, cwd, len))
error = -EFAULT;
}
- } else
- spin_unlock(&dcache_lock);
+ } else {
+ write_sequnlock(&rename_lock);
+ }
out:
path_put(&pwd);
int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
{
int result;
- unsigned long seq;
+ unsigned seq;
if (new_dentry == old_dentry)
return 1;
- /*
- * Need rcu_readlock to protect against the d_parent trashing
- * due to d_move
- */
- rcu_read_lock();
do {
/* for restarting inner loop in case of seq retry */
seq = read_seqbegin(&rename_lock);
+ /*
+ * Need rcu_readlock to protect against the d_parent trashing
+ * due to d_move
+ */
+ rcu_read_lock();
if (d_ancestor(old_dentry, new_dentry))
result = 1;
else
result = 0;
+ rcu_read_unlock();
} while (read_seqretry(&rename_lock, seq));
- rcu_read_unlock();
return result;
}
void d_genocide(struct dentry *root)
{
- struct dentry *this_parent = root;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
+ int locked = 0;
- spin_lock(&dcache_lock);
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = root;
spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
+
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
if (d_unhashed(dentry) || !dentry->d_inode) {
spin_unlock(&dentry->d_lock);
spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
- dentry->d_count--;
+ if (!(dentry->d_flags & DCACHE_GENOCIDE)) {
+ dentry->d_flags |= DCACHE_GENOCIDE;
+ dentry->d_count--;
+ }
spin_unlock(&dentry->d_lock);
}
if (this_parent != root) {
- next = this_parent->d_u.d_child.next;
- this_parent->d_count--;
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
+ this_parent->d_flags |= DCACHE_GENOCIDE;
+ this_parent->d_count--;
+ }
+ rcu_read_lock();
spin_unlock(&this_parent->d_lock);
- this_parent = this_parent->d_parent;
+ child = this_parent;
+ this_parent = tmp;
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 ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
+ return;
+
+rename_retry:
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
/**
projects / deliverable / linux.git / blobdiff