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Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c93
1 files changed, 36 insertions, 57 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 40469044088..19153a0a810 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -218,7 +218,7 @@ static void __d_free(struct rcu_head *head)
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
- WARN_ON(!list_empty(&dentry->d_alias));
+ WARN_ON(!hlist_unhashed(&dentry->d_alias));
if (dname_external(dentry))
kfree(dentry->d_name.name);
kmem_cache_free(dentry_cache, dentry);
@@ -267,7 +267,7 @@ static void dentry_iput(struct dentry * dentry)
struct inode *inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ hlist_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
if (!inode->i_nlink)
@@ -291,7 +291,7 @@ static void dentry_unlink_inode(struct dentry * dentry)
{
struct inode *inode = dentry->d_inode;
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ hlist_del_init(&dentry->d_alias);
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
@@ -389,7 +389,7 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
* Inform try_to_ascend() that we are no longer attached to the
* dentry tree
*/
- dentry->d_flags |= DCACHE_DISCONNECTED;
+ dentry->d_flags |= DCACHE_DENTRY_KILLED;
if (parent)
spin_unlock(&parent->d_lock);
dentry_iput(dentry);
@@ -455,24 +455,6 @@ void d_drop(struct dentry *dentry)
EXPORT_SYMBOL(d_drop);
/*
- * d_clear_need_lookup - drop a dentry from cache and clear the need lookup flag
- * @dentry: dentry to drop
- *
- * This is called when we do a lookup on a placeholder dentry that needed to be
- * looked up. The dentry should have been hashed in order for it to be found by
- * the lookup code, but now needs to be unhashed while we do the actual lookup
- * and clear the DCACHE_NEED_LOOKUP flag.
- */
-void d_clear_need_lookup(struct dentry *dentry)
-{
- spin_lock(&dentry->d_lock);
- __d_drop(dentry);
- dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
- spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL(d_clear_need_lookup);
-
-/*
* Finish off a dentry we've decided to kill.
* dentry->d_lock must be held, returns with it unlocked.
* If ref is non-zero, then decrement the refcount too.
@@ -565,13 +547,7 @@ repeat:
if (d_unhashed(dentry))
goto kill_it;
- /*
- * If this dentry needs lookup, don't set the referenced flag so that it
- * is more likely to be cleaned up by the dcache shrinker in case of
- * memory pressure.
- */
- if (!d_need_lookup(dentry))
- dentry->d_flags |= DCACHE_REFERENCED;
+ dentry->d_flags |= DCACHE_REFERENCED;
dentry_lru_add(dentry);
dentry->d_count--;
@@ -699,10 +675,11 @@ EXPORT_SYMBOL(dget_parent);
static struct dentry *__d_find_alias(struct inode *inode, int want_discon)
{
struct dentry *alias, *discon_alias;
+ struct hlist_node *p;
again:
discon_alias = NULL;
- list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, p, &inode->i_dentry, d_alias) {
spin_lock(&alias->d_lock);
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
@@ -737,7 +714,7 @@ struct dentry *d_find_alias(struct inode *inode)
{
struct dentry *de = NULL;
- if (!list_empty(&inode->i_dentry)) {
+ if (!hlist_empty(&inode->i_dentry)) {
spin_lock(&inode->i_lock);
de = __d_find_alias(inode, 0);
spin_unlock(&inode->i_lock);
@@ -753,9 +730,10 @@ EXPORT_SYMBOL(d_find_alias);
void d_prune_aliases(struct inode *inode)
{
struct dentry *dentry;
+ struct hlist_node *p;
restart:
spin_lock(&inode->i_lock);
- list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(dentry, p, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
__dget_dlock(dentry);
@@ -977,7 +955,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ hlist_del_init(&dentry->d_alias);
if (dentry->d_op && dentry->d_op->d_iput)
dentry->d_op->d_iput(dentry, inode);
else
@@ -1046,7 +1024,7 @@ static struct dentry *try_to_ascend(struct dentry *old, int locked, unsigned seq
* or deletion
*/
if (new != old->d_parent ||
- (old->d_flags & DCACHE_DISCONNECTED) ||
+ (old->d_flags & DCACHE_DENTRY_KILLED) ||
(!locked && read_seqretry(&rename_lock, seq))) {
spin_unlock(&new->d_lock);
new = NULL;
@@ -1132,6 +1110,8 @@ positive:
return 1;
rename_retry:
+ if (locked)
+ goto again;
locked = 1;
write_seqlock(&rename_lock);
goto again;
@@ -1139,7 +1119,7 @@ rename_retry:
EXPORT_SYMBOL(have_submounts);
/*
- * Search the dentry child list for the specified parent,
+ * Search the dentry child list of the specified parent,
* and move any unused dentries to the end of the unused
* list for prune_dcache(). We descend to the next level
* whenever the d_subdirs list is non-empty and continue
@@ -1234,6 +1214,8 @@ out:
rename_retry:
if (found)
return found;
+ if (locked)
+ goto again;
locked = 1;
write_seqlock(&rename_lock);
goto again;
@@ -1312,7 +1294,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
INIT_HLIST_BL_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
- INIT_LIST_HEAD(&dentry->d_alias);
+ INIT_HLIST_NODE(&dentry->d_alias);
INIT_LIST_HEAD(&dentry->d_u.d_child);
d_set_d_op(dentry, dentry->d_sb->s_d_op);
@@ -1400,7 +1382,7 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
if (inode) {
if (unlikely(IS_AUTOMOUNT(inode)))
dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
- list_add(&dentry->d_alias, &inode->i_dentry);
+ hlist_add_head(&dentry->d_alias, &inode->i_dentry);
}
dentry->d_inode = inode;
dentry_rcuwalk_barrier(dentry);
@@ -1425,7 +1407,7 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
void d_instantiate(struct dentry *entry, struct inode * inode)
{
- BUG_ON(!list_empty(&entry->d_alias));
+ BUG_ON(!hlist_unhashed(&entry->d_alias));
if (inode)
spin_lock(&inode->i_lock);
__d_instantiate(entry, inode);
@@ -1458,13 +1440,14 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry,
int len = entry->d_name.len;
const char *name = entry->d_name.name;
unsigned int hash = entry->d_name.hash;
+ struct hlist_node *p;
if (!inode) {
__d_instantiate(entry, NULL);
return NULL;
}
- list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, p, &inode->i_dentry, d_alias) {
/*
* Don't need alias->d_lock here, because aliases with
* d_parent == entry->d_parent are not subject to name or
@@ -1490,7 +1473,7 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
{
struct dentry *result;
- BUG_ON(!list_empty(&entry->d_alias));
+ BUG_ON(!hlist_unhashed(&entry->d_alias));
if (inode)
spin_lock(&inode->i_lock);
@@ -1531,9 +1514,9 @@ static struct dentry * __d_find_any_alias(struct inode *inode)
{
struct dentry *alias;
- if (list_empty(&inode->i_dentry))
+ if (hlist_empty(&inode->i_dentry))
return NULL;
- alias = list_first_entry(&inode->i_dentry, struct dentry, d_alias);
+ alias = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
__dget(alias);
return alias;
}
@@ -1576,7 +1559,7 @@ EXPORT_SYMBOL(d_find_any_alias);
*/
struct dentry *d_obtain_alias(struct inode *inode)
{
- static const struct qstr anonstring = { .name = "" };
+ static const struct qstr anonstring = QSTR_INIT("/", 1);
struct dentry *tmp;
struct dentry *res;
@@ -1607,7 +1590,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
spin_lock(&tmp->d_lock);
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
- list_add(&tmp->d_alias, &inode->i_dentry);
+ hlist_add_head(&tmp->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);
@@ -1730,13 +1713,6 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
}
/*
- * We are going to instantiate this dentry, unhash it and clear the
- * lookup flag so we can do that.
- */
- if (unlikely(d_need_lookup(found)))
- d_clear_need_lookup(found);
-
- /*
* Negative dentry: instantiate it unless the inode is a directory and
* already has a dentry.
*/
@@ -2106,7 +2082,7 @@ again:
inode = dentry->d_inode;
isdir = S_ISDIR(inode->i_mode);
if (dentry->d_count == 1) {
- if (inode && !spin_trylock(&inode->i_lock)) {
+ if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&dentry->d_lock);
cpu_relax();
goto again;
@@ -2384,14 +2360,13 @@ static struct dentry *__d_unalias(struct inode *inode,
struct dentry *dentry, struct dentry *alias)
{
struct mutex *m1 = NULL, *m2 = NULL;
- struct dentry *ret;
+ struct dentry *ret = ERR_PTR(-EBUSY);
/* If alias and dentry share a parent, then no extra locks required */
if (alias->d_parent == dentry->d_parent)
goto out_unalias;
/* See lock_rename() */
- ret = ERR_PTR(-EBUSY);
if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex))
goto out_err;
m1 = &dentry->d_sb->s_vfs_rename_mutex;
@@ -2399,8 +2374,10 @@ static struct dentry *__d_unalias(struct inode *inode,
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- __d_move(alias, dentry);
- ret = alias;
+ if (likely(!d_mountpoint(alias))) {
+ __d_move(alias, dentry);
+ ret = alias;
+ }
out_err:
spin_unlock(&inode->i_lock);
if (m2)
@@ -2622,7 +2599,7 @@ global_root:
if (!slash)
error = prepend(buffer, buflen, "/", 1);
if (!error)
- error = real_mount(vfsmnt)->mnt_ns ? 1 : 2;
+ error = is_mounted(vfsmnt) ? 1 : 2;
goto out;
}
@@ -3031,6 +3008,8 @@ resume:
return;
rename_retry:
+ if (locked)
+ goto again;
locked = 1;
write_seqlock(&rename_lock);
goto again;