#include <linux/security.h>
#include <linux/seqlock.h>
#include <linux/swap.h>
+#include <linux/bootmem.h>
-#define DCACHE_PARANOIA 1
/* #define DCACHE_DEBUG 1 */
+int sysctl_vfs_cache_pressure = 100;
+
spinlock_t dcache_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
seqlock_t rename_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
.age_limit = 45,
};
-static void d_callback(void *arg)
+static void d_callback(struct rcu_head *head)
{
- struct dentry * dentry = (struct dentry *)arg;
+ struct dentry * dentry = container_of(head, struct dentry, d_rcu);
if (dname_external(dentry))
kfree(dentry->d_name.name);
{
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
- call_rcu(&dentry->d_rcu, d_callback, dentry);
+ call_rcu(&dentry->d_rcu, d_callback);
}
/*
return;
repeat:
+ if (atomic_read(&dentry->d_count) == 1)
+ might_sleep();
if (!atomic_dec_and_lock(&dentry->d_count, &dcache_lock))
return;
* any other hashed alias over that one.
*/
-struct dentry * d_find_alias(struct inode *inode)
+static struct dentry * __d_find_alias(struct inode *inode, int want_discon)
{
struct list_head *head, *next, *tmp;
struct dentry *alias, *discon_alias=NULL;
- spin_lock(&dcache_lock);
head = &inode->i_dentry;
next = inode->i_dentry.next;
while (next != head) {
if (!d_unhashed(alias)) {
if (alias->d_flags & DCACHE_DISCONNECTED)
discon_alias = alias;
- else {
+ else if (!want_discon) {
__dget_locked(alias);
- spin_unlock(&dcache_lock);
return alias;
}
}
}
if (discon_alias)
__dget_locked(discon_alias);
- spin_unlock(&dcache_lock);
return discon_alias;
}
+struct dentry * d_find_alias(struct inode *inode)
+{
+ struct dentry *de;
+ spin_lock(&dcache_lock);
+ de = __d_find_alias(inode, 0);
+ spin_unlock(&dcache_lock);
+ return de;
+}
+
/*
* Try to kill dentries associated with this inode.
* WARNING: you must own a reference to inode.
*
* Prune the dentries that are anonymous
*
- * parsing d_hash list does not read_barrier_depends() as it
+ * parsing d_hash list does not hlist_for_each_rcu() as it
* done under dcache_lock.
*
*/
struct dentry *this = hlist_entry(lp, struct dentry, d_hash);
if (!list_empty(&this->d_lru)) {
dentry_stat.nr_unused--;
- list_del(&this->d_lru);
+ list_del_init(&this->d_lru);
}
/*
return -1;
prune_dcache(nr);
}
- return dentry_stat.nr_unused;
+ return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
}
/**
tmp->d_parent = tmp; /* make sure dput doesn't croak */
spin_lock(&dcache_lock);
- if (S_ISDIR(inode->i_mode) && !list_empty(&inode->i_dentry)) {
- /* A directory can only have one dentry.
- * This (now) has one, so use it.
- */
- res = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- __dget_locked(res);
- } else {
+ res = __d_find_alias(inode, 0);
+ if (!res) {
/* attach a disconnected dentry */
res = tmp;
tmp = NULL;
- if (res) {
- spin_lock(&res->d_lock);
- res->d_sb = inode->i_sb;
- res->d_parent = res;
- res->d_inode = inode;
+ spin_lock(&res->d_lock);
+ res->d_sb = inode->i_sb;
+ res->d_parent = res;
+ res->d_inode = inode;
+
+ /*
+ * Set d_bucket to an "impossible" bucket address so
+ * that d_move() doesn't get a false positive
+ */
+ res->d_bucket = NULL;
+ res->d_flags |= DCACHE_DISCONNECTED;
+ res->d_flags &= ~DCACHE_UNHASHED;
+ list_add(&res->d_alias, &inode->i_dentry);
+ hlist_add_head(&res->d_hash, &inode->i_sb->s_anon);
+ spin_unlock(&res->d_lock);
- /*
- * Set d_bucket to an "impossible" bucket address so
- * that d_move() doesn't get a false positive
- */
- res->d_bucket = NULL;
- res->d_flags |= DCACHE_DISCONNECTED;
- res->d_flags &= ~DCACHE_UNHASHED;
- list_add(&res->d_alias, &inode->i_dentry);
- hlist_add_head(&res->d_hash, &inode->i_sb->s_anon);
- spin_unlock(&res->d_lock);
- }
inode = NULL; /* don't drop reference */
}
spin_unlock(&dcache_lock);
* DCACHE_DISCONNECTED), then d_move that in place of the given dentry
* and return it, else simply d_add the inode to the dentry and return NULL.
*
- * This is (will be) needed in the lookup routine of any filesystem that is exportable
+ * This is needed in the lookup routine of any filesystem that is exportable
* (via knfsd) so that we can build dcache paths to directories effectively.
*
* If a dentry was found and moved, then it is returned. Otherwise NULL
{
struct dentry *new = NULL;
- if (inode && S_ISDIR(inode->i_mode)) {
+ if (inode) {
spin_lock(&dcache_lock);
- if (!list_empty(&inode->i_dentry)) {
- new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- __dget_locked(new);
+ new = __d_find_alias(inode, 1);
+ if (new) {
+ BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
spin_unlock(&dcache_lock);
security_d_instantiate(new, inode);
d_rehash(dentry);
rcu_read_lock();
- hlist_for_each (node, head) {
+ hlist_for_each_rcu(node, head) {
struct dentry *dentry;
struct qstr *qstr;
- smp_read_barrier_depends();
dentry = hlist_entry(node, struct dentry, d_hash);
smp_rmb();
if (dentry->d_parent != parent)
goto next;
- qstr = &dentry->d_name;
- smp_read_barrier_depends();
+ qstr = rcu_dereference(&dentry->d_name);
if (parent->d_op && parent->d_op->d_compare) {
if (parent->d_op->d_compare(parent, qstr, name))
goto next;
spin_lock(&dcache_lock);
base = d_hash(dparent, dentry->d_name.hash);
hlist_for_each(lhp,base) {
- /* read_barrier_depends() not required for d_hash list
+ /* hlist_for_each_rcu() not required for d_hash list
* as it is parsed under dcache_lock
*/
if (dentry == hlist_entry(lhp, struct dentry, d_hash)) {
}
__setup("dhash_entries=", set_dhash_entries);
-static void __init dcache_init(unsigned long mempages)
+static void __init dcache_init_early(void)
{
- struct hlist_head *d;
- unsigned long order;
- unsigned int nr_hash;
- int i;
+ int loop;
+
+ dentry_hashtable =
+ alloc_large_system_hash("Dentry cache",
+ sizeof(struct hlist_head),
+ dhash_entries,
+ 13,
+ 0,
+ &d_hash_shift,
+ &d_hash_mask);
+
+ for (loop = 0; loop < (1 << d_hash_shift); loop++)
+ INIT_HLIST_HEAD(&dentry_hashtable[loop]);
+}
+static void __init dcache_init(unsigned long mempages)
+{
/*
* A constructor could be added for stable state like the lists,
* but it is probably not worth it because of the cache nature
NULL, NULL);
set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
-
- if (!dhash_entries)
- dhash_entries = PAGE_SHIFT < 13 ?
- mempages >> (13 - PAGE_SHIFT) :
- mempages << (PAGE_SHIFT - 13);
-
- dhash_entries *= sizeof(struct hlist_head);
- for (order = 0; ((1UL << order) << PAGE_SHIFT) < dhash_entries; order++)
- ;
-
- do {
- unsigned long tmp;
-
- nr_hash = (1UL << order) * PAGE_SIZE /
- sizeof(struct hlist_head);
- d_hash_mask = (nr_hash - 1);
-
- tmp = nr_hash;
- d_hash_shift = 0;
- while ((tmp >>= 1UL) != 0UL)
- d_hash_shift++;
-
- dentry_hashtable = (struct hlist_head *)
- __get_free_pages(GFP_ATOMIC, order);
- } while (dentry_hashtable == NULL && --order >= 0);
-
- printk(KERN_INFO "Dentry cache hash table entries: %d (order: %ld, %ld bytes)\n",
- nr_hash, order, (PAGE_SIZE << order));
-
- if (!dentry_hashtable)
- panic("Failed to allocate dcache hash table\n");
-
- d = dentry_hashtable;
- i = nr_hash;
- do {
- INIT_HLIST_HEAD(d);
- d++;
- i--;
- } while (i);
}
/* SLAB cache for __getname() consumers */
extern void bdev_cache_init(void);
extern void chrdev_init(void);
+void __init vfs_caches_init_early(void)
+{
+ dcache_init_early();
+ inode_init_early();
+}
+
void __init vfs_caches_init(unsigned long mempages)
{
unsigned long reserve;
git://git.onelab.eu / linux-2.6.git / blobdiff