#include <linux/hardirq.h>
#include <linux/bit_spinlock.h>
#include <linux/rculist_bl.h>
+#include <linux/prefetch.h>
#include "internal.h"
/*
static unsigned int d_hash_mask __read_mostly;
static unsigned int d_hash_shift __read_mostly;
-struct dcache_hash_bucket {
- struct hlist_bl_head head;
-};
-static struct dcache_hash_bucket *dentry_hashtable __read_mostly;
+static struct hlist_bl_head *dentry_hashtable __read_mostly;
-static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
+static inline struct hlist_bl_head *d_hash(struct dentry *parent,
unsigned long hash)
{
hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
return dentry_hashtable + (hash & D_HASHMASK);
}
-static inline void spin_lock_bucket(struct dcache_hash_bucket *b)
-{
- bit_spin_lock(0, (unsigned long *)&b->head.first);
-}
-
-static inline void spin_unlock_bucket(struct dcache_hash_bucket *b)
-{
- __bit_spin_unlock(0, (unsigned long *)&b->head.first);
-}
-
/* Statistics gathering. */
struct dentry_stat_t dentry_stat = {
.age_limit = 45,
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
- /* if dentry was never inserted into hash, immediate free is OK */
- if (hlist_bl_unhashed(&dentry->d_hash))
+ /* if dentry was never visible to RCU, immediate free is OK */
+ if (!(dentry->d_flags & DCACHE_RCUACCESS))
__d_free(&dentry->d_u.d_rcu);
else
call_rcu(&dentry->d_u.d_rcu, __d_free);
*/
void __d_drop(struct dentry *dentry)
{
- if (!(dentry->d_flags & DCACHE_UNHASHED)) {
- if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
- bit_spin_lock(0,
- (unsigned long *)&dentry->d_sb->s_anon.first);
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_init(&dentry->d_hash);
- __bit_spin_unlock(0,
- (unsigned long *)&dentry->d_sb->s_anon.first);
- } else {
- struct dcache_hash_bucket *b;
+ if (!d_unhashed(dentry)) {
+ struct hlist_bl_head *b;
+ if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED))
+ b = &dentry->d_sb->s_anon;
+ else
b = d_hash(dentry->d_parent, dentry->d_name.hash);
- spin_lock_bucket(b);
- /*
- * We may not actually need to put DCACHE_UNHASHED
- * manipulations under the hash lock, but follow
- * the principle of least surprise.
- */
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_rcu(&dentry->d_hash);
- spin_unlock_bucket(b);
- dentry_rcuwalk_barrier(dentry);
- }
+
+ hlist_bl_lock(b);
+ __hlist_bl_del(&dentry->d_hash);
+ dentry->d_hash.pprev = NULL;
+ hlist_bl_unlock(b);
+
+ dentry_rcuwalk_barrier(dentry);
}
}
EXPORT_SYMBOL(__d_drop);
EXPORT_SYMBOL(shrink_dcache_parent);
/*
- * Scan `nr' dentries and return the number which remain.
+ * Scan `sc->nr_slab_to_reclaim' dentries and return the number which remain.
*
* We need to avoid reentering the filesystem if the caller is performing a
* GFP_NOFS allocation attempt. One example deadlock is:
*
* In this case we return -1 to tell the caller that we baled.
*/
-static int shrink_dcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
+static int shrink_dcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
{
+ int nr = sc->nr_to_scan;
+ gfp_t gfp_mask = sc->gfp_mask;
+
if (nr) {
if (!(gfp_mask & __GFP_FS))
return -1;
dname[name->len] = 0;
dentry->d_count = 1;
- dentry->d_flags = DCACHE_UNHASHED;
+ dentry->d_flags = 0;
spin_lock_init(&dentry->d_lock);
seqcount_init(&dentry->d_seq);
dentry->d_inode = NULL;
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
list_add(&tmp->d_alias, &inode->i_dentry);
- bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
- tmp->d_flags &= ~DCACHE_UNHASHED;
+ hlist_bl_lock(&tmp->d_sb->s_anon);
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
- __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
+ hlist_bl_unlock(&tmp->d_sb->s_anon);
spin_unlock(&tmp->d_lock);
spin_unlock(&inode->i_lock);
security_d_instantiate(tmp, inode);
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
- struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_head *b = d_hash(parent, hash);
struct hlist_bl_node *node;
struct dentry *dentry;
*
* See Documentation/filesystems/path-lookup.txt for more details.
*/
- hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
struct inode *i;
const char *tname;
int tlen;
tname = dentry->d_name.name;
i = dentry->d_inode;
prefetch(tname);
- if (i)
- prefetch(i);
/*
* This seqcount check is required to ensure name and
* len are loaded atomically, so as not to walk off the
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
- struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_head *b = d_hash(parent, hash);
struct hlist_bl_node *node;
struct dentry *found = NULL;
struct dentry *dentry;
*/
rcu_read_lock();
- hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
const char *tname;
int tlen;
}
EXPORT_SYMBOL(d_delete);
-static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b)
+static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
{
BUG_ON(!d_unhashed(entry));
- spin_lock_bucket(b);
- entry->d_flags &= ~DCACHE_UNHASHED;
- hlist_bl_add_head_rcu(&entry->d_hash, &b->head);
- spin_unlock_bucket(b);
+ hlist_bl_lock(b);
+ entry->d_flags |= DCACHE_RCUACCESS;
+ hlist_bl_add_head_rcu(&entry->d_hash, b);
+ hlist_bl_unlock(b);
}
static void _d_rehash(struct dentry * entry)
* The hash value has to match the hash queue that the dentry is on..
*/
/*
- * d_move - 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.
+ * dcache entries should not be moved in this way. Caller hold
+ * rename_lock.
*/
-void d_move(struct dentry * dentry, struct dentry * target)
+static void __d_move(struct dentry * dentry, struct dentry * target)
{
if (!dentry->d_inode)
printk(KERN_WARNING "VFS: moving negative dcache entry\n");
BUG_ON(d_ancestor(dentry, target));
BUG_ON(d_ancestor(target, dentry));
- write_seqlock(&rename_lock);
-
dentry_lock_for_move(dentry, target);
write_seqcount_begin(&dentry->d_seq);
spin_unlock(&target->d_lock);
fsnotify_d_move(dentry);
spin_unlock(&dentry->d_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)
+{
+ write_seqlock(&rename_lock);
+ __d_move(dentry, target);
write_sequnlock(&rename_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 inode->i_lock
+ * dentry->d_parent->d_inode->i_mutex, inode->i_lock and rename_lock
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
if (alias->d_parent == dentry->d_parent)
goto out_unalias;
- /* Check for loops */
- ret = ERR_PTR(-ELOOP);
- if (d_ancestor(alias, dentry))
- goto out_err;
-
/* See lock_rename() */
ret = ERR_PTR(-EBUSY);
if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex))
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- d_move(alias, dentry);
+ __d_move(alias, dentry);
ret = alias;
out_err:
spin_unlock(&inode->i_lock);
alias = __d_find_alias(inode, 0);
if (alias) {
actual = alias;
- /* Is this an anonymous mountpoint that we could splice
- * into our tree? */
- if (IS_ROOT(alias)) {
+ write_seqlock(&rename_lock);
+
+ if (d_ancestor(alias, dentry)) {
+ /* Check for loops */
+ actual = ERR_PTR(-ELOOP);
+ } else if (IS_ROOT(alias)) {
+ /* Is this an anonymous mountpoint that we
+ * could splice into our tree? */
__d_materialise_dentry(dentry, alias);
+ write_sequnlock(&rename_lock);
__d_drop(alias);
goto found;
+ } else {
+ /* Nope, but we must(!) avoid directory
+ * aliasing */
+ actual = __d_unalias(inode, dentry, alias);
}
- /* Nope, but we must(!) avoid directory aliasing */
- actual = __d_unalias(inode, dentry, alias);
+ write_sequnlock(&rename_lock);
if (IS_ERR(actual))
dput(alias);
goto out_nolock;
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct dcache_hash_bucket),
+ sizeof(struct hlist_bl_head),
dhash_entries,
13,
HASH_EARLY,
0);
for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+ INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}
static void __init dcache_init(void)
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct dcache_hash_bucket),
+ sizeof(struct hlist_bl_head),
dhash_entries,
13,
0,
0);
for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+ INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}
/* SLAB cache for __getname() consumers */
git.openpandora.org / pandora-kernel.git / blobdiff