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Diffstat (limited to 'net/sunrpc/cache.c')
-rw-r--r--net/sunrpc/cache.c288
1 files changed, 201 insertions, 87 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 7dce81a926c5..e433e7580e27 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -33,15 +33,16 @@
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
+#include "netns.h"
#define RPCDBG_FACILITY RPCDBG_CACHE
-static int cache_defer_req(struct cache_req *req, struct cache_head *item);
+static void 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)
{
- time_t now = get_seconds();
+ time_t now = seconds_since_boot();
h->next = NULL;
h->flags = 0;
kref_init(&h->ref);
@@ -51,7 +52,7 @@ static void cache_init(struct cache_head *h)
static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
{
- return (h->expiry_time < get_seconds()) ||
+ return (h->expiry_time < seconds_since_boot()) ||
(detail->flush_time > h->last_refresh);
}
@@ -126,7 +127,7 @@ static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
static void cache_fresh_locked(struct cache_head *head, time_t expiry)
{
head->expiry_time = expiry;
- head->last_refresh = get_seconds();
+ head->last_refresh = seconds_since_boot();
set_bit(CACHE_VALID, &head->flags);
}
@@ -237,7 +238,7 @@ int cache_check(struct cache_detail *detail,
/* now see if we want to start an upcall */
refresh_age = (h->expiry_time - h->last_refresh);
- age = get_seconds() - h->last_refresh;
+ age = seconds_since_boot() - h->last_refresh;
if (rqstp == NULL) {
if (rv == -EAGAIN)
@@ -252,7 +253,7 @@ int cache_check(struct cache_detail *detail,
cache_revisit_request(h);
if (rv == -EAGAIN) {
set_bit(CACHE_NEGATIVE, &h->flags);
- cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY);
+ cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
cache_fresh_unlocked(h, detail);
rv = -ENOENT;
}
@@ -267,7 +268,8 @@ int cache_check(struct cache_detail *detail,
}
if (rv == -EAGAIN) {
- if (cache_defer_req(rqstp, h) < 0) {
+ cache_defer_req(rqstp, h);
+ if (!test_bit(CACHE_PENDING, &h->flags)) {
/* Request is not deferred */
rv = cache_is_valid(detail, h);
if (rv == -EAGAIN)
@@ -387,11 +389,11 @@ static int cache_clean(void)
return -1;
}
current_detail = list_entry(next, struct cache_detail, others);
- if (current_detail->nextcheck > get_seconds())
+ if (current_detail->nextcheck > seconds_since_boot())
current_index = current_detail->hash_size;
else {
current_index = 0;
- current_detail->nextcheck = get_seconds()+30*60;
+ current_detail->nextcheck = seconds_since_boot()+30*60;
}
}
@@ -476,7 +478,7 @@ EXPORT_SYMBOL_GPL(cache_flush);
void cache_purge(struct cache_detail *detail)
{
detail->flush_time = LONG_MAX;
- detail->nextcheck = get_seconds();
+ detail->nextcheck = seconds_since_boot();
cache_flush();
detail->flush_time = 1;
}
@@ -505,81 +507,155 @@ EXPORT_SYMBOL_GPL(cache_purge);
static DEFINE_SPINLOCK(cache_defer_lock);
static LIST_HEAD(cache_defer_list);
-static struct list_head cache_defer_hash[DFR_HASHSIZE];
+static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
static int cache_defer_cnt;
-static int cache_defer_req(struct cache_req *req, struct cache_head *item)
+static void __unhash_deferred_req(struct cache_deferred_req *dreq)
+{
+ hlist_del_init(&dreq->hash);
+ if (!list_empty(&dreq->recent)) {
+ list_del_init(&dreq->recent);
+ cache_defer_cnt--;
+ }
+}
+
+static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
{
- struct cache_deferred_req *dreq, *discard;
int hash = DFR_HASH(item);
- if (cache_defer_cnt >= DFR_MAX) {
- /* too much in the cache, randomly drop this one,
- * or continue and drop the oldest below
- */
- if (net_random()&1)
- return -ENOMEM;
- }
- dreq = req->defer(req);
- if (dreq == NULL)
- return -ENOMEM;
+ INIT_LIST_HEAD(&dreq->recent);
+ hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
+}
+
+static void setup_deferral(struct cache_deferred_req *dreq,
+ struct cache_head *item,
+ int count_me)
+{
dreq->item = item;
spin_lock(&cache_defer_lock);
- list_add(&dreq->recent, &cache_defer_list);
-
- if (cache_defer_hash[hash].next == NULL)
- INIT_LIST_HEAD(&cache_defer_hash[hash]);
- list_add(&dreq->hash, &cache_defer_hash[hash]);
+ __hash_deferred_req(dreq, item);
- /* it is in, now maybe clean up */
- discard = NULL;
- if (++cache_defer_cnt > DFR_MAX) {
- discard = list_entry(cache_defer_list.prev,
- struct cache_deferred_req, recent);
- list_del_init(&discard->recent);
- list_del_init(&discard->hash);
- cache_defer_cnt--;
+ if (count_me) {
+ cache_defer_cnt++;
+ list_add(&dreq->recent, &cache_defer_list);
}
+
spin_unlock(&cache_defer_lock);
+}
+
+struct thread_deferred_req {
+ struct cache_deferred_req handle;
+ struct completion completion;
+};
+
+static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
+{
+ struct thread_deferred_req *dr =
+ container_of(dreq, struct thread_deferred_req, handle);
+ complete(&dr->completion);
+}
+
+static void cache_wait_req(struct cache_req *req, struct cache_head *item)
+{
+ struct thread_deferred_req sleeper;
+ struct cache_deferred_req *dreq = &sleeper.handle;
+
+ sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
+ dreq->revisit = cache_restart_thread;
+
+ setup_deferral(dreq, item, 0);
+
+ if (!test_bit(CACHE_PENDING, &item->flags) ||
+ wait_for_completion_interruptible_timeout(
+ &sleeper.completion, req->thread_wait) <= 0) {
+ /* The completion wasn't completed, so we need
+ * to clean up
+ */
+ spin_lock(&cache_defer_lock);
+ if (!hlist_unhashed(&sleeper.handle.hash)) {
+ __unhash_deferred_req(&sleeper.handle);
+ spin_unlock(&cache_defer_lock);
+ } else {
+ /* cache_revisit_request already removed
+ * this from the hash table, but hasn't
+ * called ->revisit yet. It will very soon
+ * and we need to wait for it.
+ */
+ spin_unlock(&cache_defer_lock);
+ wait_for_completion(&sleeper.completion);
+ }
+ }
+}
+
+static void cache_limit_defers(void)
+{
+ /* Make sure we haven't exceed the limit of allowed deferred
+ * requests.
+ */
+ struct cache_deferred_req *discard = NULL;
+
+ if (cache_defer_cnt <= DFR_MAX)
+ return;
+
+ spin_lock(&cache_defer_lock);
+
+ /* Consider removing either the first or the last */
+ if (cache_defer_cnt > DFR_MAX) {
+ if (net_random() & 1)
+ discard = list_entry(cache_defer_list.next,
+ struct cache_deferred_req, recent);
+ else
+ discard = list_entry(cache_defer_list.prev,
+ struct cache_deferred_req, recent);
+ __unhash_deferred_req(discard);
+ }
+ spin_unlock(&cache_defer_lock);
if (discard)
- /* there was one too many */
discard->revisit(discard, 1);
+}
- if (!test_bit(CACHE_PENDING, &item->flags)) {
- /* must have just been validated... */
- cache_revisit_request(item);
- return -EAGAIN;
+static void cache_defer_req(struct cache_req *req, struct cache_head *item)
+{
+ struct cache_deferred_req *dreq;
+
+ if (req->thread_wait) {
+ cache_wait_req(req, item);
+ if (!test_bit(CACHE_PENDING, &item->flags))
+ return;
}
- return 0;
+ dreq = req->defer(req);
+ if (dreq == NULL)
+ return;
+ setup_deferral(dreq, item, 1);
+ if (!test_bit(CACHE_PENDING, &item->flags))
+ /* Bit could have been cleared before we managed to
+ * set up the deferral, so need to revisit just in case
+ */
+ cache_revisit_request(item);
+
+ cache_limit_defers();
}
static void cache_revisit_request(struct cache_head *item)
{
struct cache_deferred_req *dreq;
struct list_head pending;
-
- struct list_head *lp;
+ struct hlist_node *lp, *tmp;
int hash = DFR_HASH(item);
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
- lp = cache_defer_hash[hash].next;
- if (lp) {
- while (lp != &cache_defer_hash[hash]) {
- dreq = list_entry(lp, struct cache_deferred_req, hash);
- lp = lp->next;
- if (dreq->item == item) {
- list_del_init(&dreq->hash);
- list_move(&dreq->recent, &pending);
- cache_defer_cnt--;
- }
+ hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
+ if (dreq->item == item) {
+ __unhash_deferred_req(dreq);
+ list_add(&dreq->recent, &pending);
}
- }
+
spin_unlock(&cache_defer_lock);
while (!list_empty(&pending)) {
@@ -600,9 +676,8 @@ void cache_clean_deferred(void *owner)
list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
if (dreq->owner == owner) {
- list_del_init(&dreq->hash);
- list_move(&dreq->recent, &pending);
- cache_defer_cnt--;
+ __unhash_deferred_req(dreq);
+ list_add(&dreq->recent, &pending);
}
}
spin_unlock(&cache_defer_lock);
@@ -901,7 +976,7 @@ static int cache_release(struct inode *inode, struct file *filp,
filp->private_data = NULL;
kfree(rp);
- cd->last_close = get_seconds();
+ cd->last_close = seconds_since_boot();
atomic_dec(&cd->readers);
}
module_put(cd->owner);
@@ -1014,6 +1089,23 @@ static void warn_no_listener(struct cache_detail *detail)
}
}
+static bool cache_listeners_exist(struct cache_detail *detail)
+{
+ if (atomic_read(&detail->readers))
+ return true;
+ if (detail->last_close == 0)
+ /* This cache was never opened */
+ return false;
+ if (detail->last_close < seconds_since_boot() - 30)
+ /*
+ * We allow for the possibility that someone might
+ * restart a userspace daemon without restarting the
+ * server; but after 30 seconds, we give up.
+ */
+ return false;
+ return true;
+}
+
/*
* register an upcall request to user-space and queue it up for read() by the
* upcall daemon.
@@ -1032,10 +1124,9 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
char *bp;
int len;
- if (atomic_read(&detail->readers) == 0 &&
- detail->last_close < get_seconds() - 30) {
- warn_no_listener(detail);
- return -EINVAL;
+ if (!cache_listeners_exist(detail)) {
+ warn_no_listener(detail);
+ return -EINVAL;
}
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
@@ -1094,13 +1185,19 @@ int qword_get(char **bpp, char *dest, int bufsize)
if (bp[0] == '\\' && bp[1] == 'x') {
/* HEX STRING */
bp += 2;
- while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) {
- int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
- bp++;
- byte <<= 4;
- byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
- *dest++ = byte;
- bp++;
+ while (len < bufsize) {
+ int h, l;
+
+ h = hex_to_bin(bp[0]);
+ if (h < 0)
+ break;
+
+ l = hex_to_bin(bp[1]);
+ if (l < 0)
+ break;
+
+ *dest++ = (h << 4) | l;
+ bp += 2;
len++;
}
} else {
@@ -1218,7 +1315,8 @@ static int c_show(struct seq_file *m, void *p)
ifdebug(CACHE)
seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
- cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
+ convert_to_wallclock(cp->expiry_time),
+ atomic_read(&cp->ref.refcount), cp->flags);
cache_get(cp);
if (cache_check(cd, cp, NULL))
/* cache_check does a cache_put on failure */
@@ -1284,7 +1382,7 @@ static ssize_t read_flush(struct file *file, char __user *buf,
unsigned long p = *ppos;
size_t len;
- sprintf(tbuf, "%lu\n", cd->flush_time);
+ sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
len = strlen(tbuf);
if (p >= len)
return 0;
@@ -1302,19 +1400,20 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
struct cache_detail *cd)
{
char tbuf[20];
- char *ep;
- long flushtime;
+ char *bp, *ep;
+
if (*ppos || count > sizeof(tbuf)-1)
return -EINVAL;
if (copy_from_user(tbuf, buf, count))
return -EFAULT;
tbuf[count] = 0;
- flushtime = simple_strtoul(tbuf, &ep, 0);
+ simple_strtoul(tbuf, &ep, 0);
if (*ep && *ep != '\n')
return -EINVAL;
- cd->flush_time = flushtime;
- cd->nextcheck = get_seconds();
+ bp = tbuf;
+ cd->flush_time = get_expiry(&bp);
+ cd->nextcheck = seconds_since_boot();
cache_flush();
*ppos += count;
@@ -1438,8 +1537,10 @@ static const struct file_operations cache_flush_operations_procfs = {
.llseek = no_llseek,
};
-static void remove_cache_proc_entries(struct cache_detail *cd)
+static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net)
{
+ struct sunrpc_net *sn;
+
if (cd->u.procfs.proc_ent == NULL)
return;
if (cd->u.procfs.flush_ent)
@@ -1449,15 +1550,18 @@ static void remove_cache_proc_entries(struct cache_detail *cd)
if (cd->u.procfs.content_ent)
remove_proc_entry("content", cd->u.procfs.proc_ent);
cd->u.procfs.proc_ent = NULL;
- remove_proc_entry(cd->name, proc_net_rpc);
+ sn = net_generic(net, sunrpc_net_id);
+ remove_proc_entry(cd->name, sn->proc_net_rpc);
}
#ifdef CONFIG_PROC_FS
-static int create_cache_proc_entries(struct cache_detail *cd)
+static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
{
struct proc_dir_entry *p;
+ struct sunrpc_net *sn;
- cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc);
+ sn = net_generic(net, sunrpc_net_id);
+ cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc);
if (cd->u.procfs.proc_ent == NULL)
goto out_nomem;
cd->u.procfs.channel_ent = NULL;
@@ -1488,11 +1592,11 @@ static int create_cache_proc_entries(struct cache_detail *cd)
}
return 0;
out_nomem:
- remove_cache_proc_entries(cd);
+ remove_cache_proc_entries(cd, net);
return -ENOMEM;
}
#else /* CONFIG_PROC_FS */
-static int create_cache_proc_entries(struct cache_detail *cd)
+static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
{
return 0;
}
@@ -1503,23 +1607,33 @@ void __init cache_initialize(void)
INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean);
}
-int cache_register(struct cache_detail *cd)
+int cache_register_net(struct cache_detail *cd, struct net *net)
{
int ret;
sunrpc_init_cache_detail(cd);
- ret = create_cache_proc_entries(cd);
+ ret = create_cache_proc_entries(cd, net);
if (ret)
sunrpc_destroy_cache_detail(cd);
return ret;
}
+
+int cache_register(struct cache_detail *cd)
+{
+ return cache_register_net(cd, &init_net);
+}
EXPORT_SYMBOL_GPL(cache_register);
-void cache_unregister(struct cache_detail *cd)
+void cache_unregister_net(struct cache_detail *cd, struct net *net)
{
- remove_cache_proc_entries(cd);
+ remove_cache_proc_entries(cd, net);
sunrpc_destroy_cache_detail(cd);
}
+
+void cache_unregister(struct cache_detail *cd)
+{
+ cache_unregister_net(cd, &init_net);
+}
EXPORT_SYMBOL_GPL(cache_unregister);
static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,