summaryrefslogtreecommitdiffstats
path: root/kernel/net/sunrpc/cache.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/net/sunrpc/cache.c')
-rw-r--r--kernel/net/sunrpc/cache.c158
1 files changed, 94 insertions, 64 deletions
diff --git a/kernel/net/sunrpc/cache.c b/kernel/net/sunrpc/cache.c
index 2928afffb..21e203531 100644
--- a/kernel/net/sunrpc/cache.c
+++ b/kernel/net/sunrpc/cache.c
@@ -41,28 +41,30 @@
static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
static void cache_revisit_request(struct cache_head *item);
-static void cache_init(struct cache_head *h)
+static void cache_init(struct cache_head *h, struct cache_detail *detail)
{
time_t now = seconds_since_boot();
- h->next = NULL;
+ INIT_HLIST_NODE(&h->cache_list);
h->flags = 0;
kref_init(&h->ref);
h->expiry_time = now + CACHE_NEW_EXPIRY;
+ if (now <= detail->flush_time)
+ /* ensure it isn't already expired */
+ now = detail->flush_time + 1;
h->last_refresh = now;
}
struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
struct cache_head *key, int hash)
{
- struct cache_head **head, **hp;
- struct cache_head *new = NULL, *freeme = NULL;
+ struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;
+ struct hlist_head *head;
head = &detail->hash_table[hash];
read_lock(&detail->hash_lock);
- for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
- struct cache_head *tmp = *hp;
+ hlist_for_each_entry(tmp, head, cache_list) {
if (detail->match(tmp, key)) {
if (cache_is_expired(detail, tmp))
/* This entry is expired, we will discard it. */
@@ -82,18 +84,16 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
* we might get lose if we need to
* cache_put it soon.
*/
- cache_init(new);
+ cache_init(new, detail);
detail->init(new, key);
write_lock(&detail->hash_lock);
/* check if entry appeared while we slept */
- for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
- struct cache_head *tmp = *hp;
+ hlist_for_each_entry(tmp, head, cache_list) {
if (detail->match(tmp, key)) {
if (cache_is_expired(detail, tmp)) {
- *hp = tmp->next;
- tmp->next = NULL;
+ hlist_del_init(&tmp->cache_list);
detail->entries --;
freeme = tmp;
break;
@@ -104,8 +104,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
return tmp;
}
}
- new->next = *head;
- *head = new;
+
+ hlist_add_head(&new->cache_list, head);
detail->entries++;
cache_get(new);
write_unlock(&detail->hash_lock);
@@ -119,10 +119,15 @@ EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
-static void cache_fresh_locked(struct cache_head *head, time_t expiry)
+static void cache_fresh_locked(struct cache_head *head, time_t expiry,
+ struct cache_detail *detail)
{
+ time_t now = seconds_since_boot();
+ if (now <= detail->flush_time)
+ /* ensure it isn't immediately treated as expired */
+ now = detail->flush_time + 1;
head->expiry_time = expiry;
- head->last_refresh = seconds_since_boot();
+ head->last_refresh = now;
smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
set_bit(CACHE_VALID, &head->flags);
}
@@ -143,7 +148,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
* If 'old' is not VALID, we update it directly,
* otherwise we need to replace it
*/
- struct cache_head **head;
struct cache_head *tmp;
if (!test_bit(CACHE_VALID, &old->flags)) {
@@ -153,7 +157,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
set_bit(CACHE_NEGATIVE, &old->flags);
else
detail->update(old, new);
- cache_fresh_locked(old, new->expiry_time);
+ cache_fresh_locked(old, new->expiry_time, detail);
write_unlock(&detail->hash_lock);
cache_fresh_unlocked(old, detail);
return old;
@@ -166,21 +170,19 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
cache_put(old, detail);
return NULL;
}
- cache_init(tmp);
+ cache_init(tmp, detail);
detail->init(tmp, old);
- head = &detail->hash_table[hash];
write_lock(&detail->hash_lock);
if (test_bit(CACHE_NEGATIVE, &new->flags))
set_bit(CACHE_NEGATIVE, &tmp->flags);
else
detail->update(tmp, new);
- tmp->next = *head;
- *head = tmp;
+ hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
detail->entries++;
cache_get(tmp);
- cache_fresh_locked(tmp, new->expiry_time);
- cache_fresh_locked(old, 0);
+ cache_fresh_locked(tmp, new->expiry_time, detail);
+ cache_fresh_locked(old, 0, detail);
write_unlock(&detail->hash_lock);
cache_fresh_unlocked(tmp, detail);
cache_fresh_unlocked(old, detail);
@@ -225,7 +227,8 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h
rv = cache_is_valid(h);
if (rv == -EAGAIN) {
set_bit(CACHE_NEGATIVE, &h->flags);
- cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
+ cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
+ detail);
rv = -ENOENT;
}
write_unlock(&detail->hash_lock);
@@ -416,28 +419,29 @@ static int cache_clean(void)
/* find a non-empty bucket in the table */
while (current_detail &&
current_index < current_detail->hash_size &&
- current_detail->hash_table[current_index] == NULL)
+ hlist_empty(&current_detail->hash_table[current_index]))
current_index++;
/* find a cleanable entry in the bucket and clean it, or set to next bucket */
if (current_detail && current_index < current_detail->hash_size) {
- struct cache_head *ch, **cp;
+ struct cache_head *ch = NULL;
struct cache_detail *d;
+ struct hlist_head *head;
+ struct hlist_node *tmp;
write_lock(&current_detail->hash_lock);
/* Ok, now to clean this strand */
- cp = & current_detail->hash_table[current_index];
- for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {
+ head = &current_detail->hash_table[current_index];
+ hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
if (current_detail->nextcheck > ch->expiry_time)
current_detail->nextcheck = ch->expiry_time+1;
if (!cache_is_expired(current_detail, ch))
continue;
- *cp = ch->next;
- ch->next = NULL;
+ hlist_del_init(&ch->cache_list);
current_detail->entries--;
rv = 1;
break;
@@ -492,10 +496,13 @@ EXPORT_SYMBOL_GPL(cache_flush);
void cache_purge(struct cache_detail *detail)
{
- detail->flush_time = LONG_MAX;
+ time_t now = seconds_since_boot();
+ if (detail->flush_time >= now)
+ now = detail->flush_time + 1;
+ /* 'now' is the maximum value any 'last_refresh' can have */
+ detail->flush_time = now;
detail->nextcheck = seconds_since_boot();
cache_flush();
- detail->flush_time = 1;
}
EXPORT_SYMBOL_GPL(cache_purge);
@@ -1218,7 +1225,7 @@ int qword_get(char **bpp, char *dest, int bufsize)
if (bp[0] == '\\' && bp[1] == 'x') {
/* HEX STRING */
bp += 2;
- while (len < bufsize) {
+ while (len < bufsize - 1) {
int h, l;
h = hex_to_bin(bp[0]);
@@ -1270,18 +1277,13 @@ EXPORT_SYMBOL_GPL(qword_get);
* get a header, then pass each real item in the cache
*/
-struct handle {
- struct cache_detail *cd;
-};
-
-static void *c_start(struct seq_file *m, loff_t *pos)
+void *cache_seq_start(struct seq_file *m, loff_t *pos)
__acquires(cd->hash_lock)
{
loff_t n = *pos;
unsigned int hash, entry;
struct cache_head *ch;
- struct cache_detail *cd = ((struct handle*)m->private)->cd;
-
+ struct cache_detail *cd = m->private;
read_lock(&cd->hash_lock);
if (!n--)
@@ -1289,7 +1291,7 @@ static void *c_start(struct seq_file *m, loff_t *pos)
hash = n >> 32;
entry = n & ((1LL<<32) - 1);
- for (ch=cd->hash_table[hash]; ch; ch=ch->next)
+ hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list)
if (!entry--)
return ch;
n &= ~((1LL<<32) - 1);
@@ -1297,51 +1299,57 @@ static void *c_start(struct seq_file *m, loff_t *pos)
hash++;
n += 1LL<<32;
} while(hash < cd->hash_size &&
- cd->hash_table[hash]==NULL);
+ hlist_empty(&cd->hash_table[hash]));
if (hash >= cd->hash_size)
return NULL;
*pos = n+1;
- return cd->hash_table[hash];
+ return hlist_entry_safe(cd->hash_table[hash].first,
+ struct cache_head, cache_list);
}
+EXPORT_SYMBOL_GPL(cache_seq_start);
-static void *c_next(struct seq_file *m, void *p, loff_t *pos)
+void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
{
struct cache_head *ch = p;
int hash = (*pos >> 32);
- struct cache_detail *cd = ((struct handle*)m->private)->cd;
+ struct cache_detail *cd = m->private;
if (p == SEQ_START_TOKEN)
hash = 0;
- else if (ch->next == NULL) {
+ else if (ch->cache_list.next == NULL) {
hash++;
*pos += 1LL<<32;
} else {
++*pos;
- return ch->next;
+ return hlist_entry_safe(ch->cache_list.next,
+ struct cache_head, cache_list);
}
*pos &= ~((1LL<<32) - 1);
while (hash < cd->hash_size &&
- cd->hash_table[hash] == NULL) {
+ hlist_empty(&cd->hash_table[hash])) {
hash++;
*pos += 1LL<<32;
}
if (hash >= cd->hash_size)
return NULL;
++*pos;
- return cd->hash_table[hash];
+ return hlist_entry_safe(cd->hash_table[hash].first,
+ struct cache_head, cache_list);
}
+EXPORT_SYMBOL_GPL(cache_seq_next);
-static void c_stop(struct seq_file *m, void *p)
+void cache_seq_stop(struct seq_file *m, void *p)
__releases(cd->hash_lock)
{
- struct cache_detail *cd = ((struct handle*)m->private)->cd;
+ struct cache_detail *cd = m->private;
read_unlock(&cd->hash_lock);
}
+EXPORT_SYMBOL_GPL(cache_seq_stop);
static int c_show(struct seq_file *m, void *p)
{
struct cache_head *cp = p;
- struct cache_detail *cd = ((struct handle*)m->private)->cd;
+ struct cache_detail *cd = m->private;
if (p == SEQ_START_TOKEN)
return cd->cache_show(m, cd, NULL);
@@ -1364,33 +1372,36 @@ static int c_show(struct seq_file *m, void *p)
}
static const struct seq_operations cache_content_op = {
- .start = c_start,
- .next = c_next,
- .stop = c_stop,
+ .start = cache_seq_start,
+ .next = cache_seq_next,
+ .stop = cache_seq_stop,
.show = c_show,
};
static int content_open(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
- struct handle *han;
+ struct seq_file *seq;
+ int err;
if (!cd || !try_module_get(cd->owner))
return -EACCES;
- han = __seq_open_private(file, &cache_content_op, sizeof(*han));
- if (han == NULL) {
+
+ err = seq_open(file, &cache_content_op);
+ if (err) {
module_put(cd->owner);
- return -ENOMEM;
+ return err;
}
- han->cd = cd;
+ seq = file->private_data;
+ seq->private = cd;
return 0;
}
static int content_release(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
- int ret = seq_release_private(inode, file);
+ int ret = seq_release(inode, file);
module_put(cd->owner);
return ret;
}
@@ -1437,6 +1448,7 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
{
char tbuf[20];
char *bp, *ep;
+ time_t then, now;
if (*ppos || count > sizeof(tbuf)-1)
return -EINVAL;
@@ -1448,8 +1460,22 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
return -EINVAL;
bp = tbuf;
- cd->flush_time = get_expiry(&bp);
- cd->nextcheck = seconds_since_boot();
+ then = get_expiry(&bp);
+ now = seconds_since_boot();
+ cd->nextcheck = now;
+ /* Can only set flush_time to 1 second beyond "now", or
+ * possibly 1 second beyond flushtime. This is because
+ * flush_time never goes backwards so it mustn't get too far
+ * ahead of time.
+ */
+ if (then >= now) {
+ /* Want to flush everything, so behave like cache_purge() */
+ if (cd->flush_time >= now)
+ now = cd->flush_time + 1;
+ then = now;
+ }
+
+ cd->flush_time = then;
cache_flush();
*ppos += count;
@@ -1665,17 +1691,21 @@ EXPORT_SYMBOL_GPL(cache_unregister_net);
struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)
{
struct cache_detail *cd;
+ int i;
cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
if (cd == NULL)
return ERR_PTR(-ENOMEM);
- cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *),
+ cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head),
GFP_KERNEL);
if (cd->hash_table == NULL) {
kfree(cd);
return ERR_PTR(-ENOMEM);
}
+
+ for (i = 0; i < cd->hash_size; i++)
+ INIT_HLIST_HEAD(&cd->hash_table[i]);
cd->net = net;
return cd;
}