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-rw-r--r--net/sunrpc/cache.c239
1 files changed, 129 insertions, 110 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index bd843a81afa0..f075a9fb5ccc 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -32,13 +32,15 @@
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <trace/events/sunrpc.h>
+
#include "netns.h"
+#include "fail.h"
#define RPCDBG_FACILITY RPCDBG_CACHE
static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
static void cache_revisit_request(struct cache_head *item);
-static bool cache_listeners_exist(struct cache_detail *detail);
static void cache_init(struct cache_head *h, struct cache_detail *detail)
{
@@ -65,13 +67,14 @@ static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
rcu_read_lock();
hlist_for_each_entry_rcu(tmp, head, cache_list) {
- if (detail->match(tmp, key)) {
- if (cache_is_expired(detail, tmp))
- continue;
- tmp = cache_get_rcu(tmp);
- rcu_read_unlock();
- return tmp;
- }
+ if (!detail->match(tmp, key))
+ continue;
+ if (test_bit(CACHE_VALID, &tmp->flags) &&
+ cache_is_expired(detail, tmp))
+ continue;
+ tmp = cache_get_rcu(tmp);
+ rcu_read_unlock();
+ return tmp;
}
rcu_read_unlock();
return NULL;
@@ -113,18 +116,21 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
spin_lock(&detail->hash_lock);
/* check if entry appeared while we slept */
- hlist_for_each_entry_rcu(tmp, head, cache_list) {
- if (detail->match(tmp, key)) {
- if (cache_is_expired(detail, tmp)) {
- sunrpc_begin_cache_remove_entry(tmp, detail);
- freeme = tmp;
- break;
- }
- cache_get(tmp);
- spin_unlock(&detail->hash_lock);
- cache_put(new, detail);
- return tmp;
+ hlist_for_each_entry_rcu(tmp, head, cache_list,
+ lockdep_is_held(&detail->hash_lock)) {
+ if (!detail->match(tmp, key))
+ continue;
+ if (test_bit(CACHE_VALID, &tmp->flags) &&
+ cache_is_expired(detail, tmp)) {
+ sunrpc_begin_cache_remove_entry(tmp, detail);
+ trace_cache_entry_expired(detail, tmp);
+ freeme = tmp;
+ break;
}
+ cache_get(tmp);
+ spin_unlock(&detail->hash_lock);
+ cache_put(new, detail);
+ return tmp;
}
hlist_add_head_rcu(&new->cache_list, head);
@@ -174,6 +180,25 @@ static void cache_fresh_unlocked(struct cache_head *head,
}
}
+static void cache_make_negative(struct cache_detail *detail,
+ struct cache_head *h)
+{
+ set_bit(CACHE_NEGATIVE, &h->flags);
+ trace_cache_entry_make_negative(detail, h);
+}
+
+static void cache_entry_update(struct cache_detail *detail,
+ struct cache_head *h,
+ struct cache_head *new)
+{
+ if (!test_bit(CACHE_NEGATIVE, &new->flags)) {
+ detail->update(h, new);
+ trace_cache_entry_update(detail, h);
+ } else {
+ cache_make_negative(detail, h);
+ }
+}
+
struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
struct cache_head *new, struct cache_head *old, int hash)
{
@@ -186,10 +211,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
if (!test_bit(CACHE_VALID, &old->flags)) {
spin_lock(&detail->hash_lock);
if (!test_bit(CACHE_VALID, &old->flags)) {
- if (test_bit(CACHE_NEGATIVE, &new->flags))
- set_bit(CACHE_NEGATIVE, &old->flags);
- else
- detail->update(old, new);
+ cache_entry_update(detail, old, new);
cache_fresh_locked(old, new->expiry_time, detail);
spin_unlock(&detail->hash_lock);
cache_fresh_unlocked(old, detail);
@@ -207,10 +229,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
detail->init(tmp, old);
spin_lock(&detail->hash_lock);
- if (test_bit(CACHE_NEGATIVE, &new->flags))
- set_bit(CACHE_NEGATIVE, &tmp->flags);
- else
- detail->update(tmp, new);
+ cache_entry_update(detail, tmp, new);
hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
detail->entries++;
cache_get(tmp);
@@ -224,13 +243,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
}
EXPORT_SYMBOL_GPL(sunrpc_cache_update);
-static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
-{
- if (cd->cache_upcall)
- return cd->cache_upcall(cd, h);
- return sunrpc_cache_pipe_upcall(cd, h);
-}
-
static inline int cache_is_valid(struct cache_head *h)
{
if (!test_bit(CACHE_VALID, &h->flags))
@@ -259,7 +271,7 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h
spin_lock(&detail->hash_lock);
rv = cache_is_valid(h);
if (rv == -EAGAIN) {
- set_bit(CACHE_NEGATIVE, &h->flags);
+ cache_make_negative(detail, h);
cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
detail);
rv = -ENOENT;
@@ -303,17 +315,14 @@ int cache_check(struct cache_detail *detail,
(h->expiry_time != 0 && age > refresh_age/2)) {
dprintk("RPC: Want update, refage=%lld, age=%lld\n",
refresh_age, age);
- if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
- switch (cache_make_upcall(detail, h)) {
- case -EINVAL:
- rv = try_to_negate_entry(detail, h);
- break;
- case -EAGAIN:
- cache_fresh_unlocked(h, detail);
- break;
- }
- } else if (!cache_listeners_exist(detail))
+ switch (detail->cache_upcall(detail, h)) {
+ case -EINVAL:
rv = try_to_negate_entry(detail, h);
+ break;
+ case -EAGAIN:
+ cache_fresh_unlocked(h, detail);
+ break;
+ }
}
if (rv == -EAGAIN) {
@@ -468,6 +477,7 @@ static int cache_clean(void)
continue;
sunrpc_begin_cache_remove_entry(ch, current_detail);
+ trace_cache_entry_expired(current_detail, ch);
rv = 1;
break;
}
@@ -490,16 +500,17 @@ static int cache_clean(void)
*/
static void do_cache_clean(struct work_struct *work)
{
- int delay = 5;
- if (cache_clean() == -1)
- delay = round_jiffies_relative(30*HZ);
+ int delay;
if (list_empty(&cache_list))
- delay = 0;
+ return;
- if (delay)
- queue_delayed_work(system_power_efficient_wq,
- &cache_cleaner, delay);
+ if (cache_clean() == -1)
+ delay = round_jiffies_relative(30*HZ);
+ else
+ delay = 5;
+
+ queue_delayed_work(system_power_efficient_wq, &cache_cleaner, delay);
}
@@ -521,7 +532,6 @@ void cache_purge(struct cache_detail *detail)
{
struct cache_head *ch = NULL;
struct hlist_head *head = NULL;
- struct hlist_node *tmp = NULL;
int i = 0;
spin_lock(&detail->hash_lock);
@@ -533,7 +543,9 @@ void cache_purge(struct cache_detail *detail)
dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name);
for (i = 0; i < detail->hash_size; i++) {
head = &detail->hash_table[i];
- hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
+ while (!hlist_empty(head)) {
+ ch = hlist_entry(head->first, struct cache_head,
+ cache_list);
sunrpc_begin_cache_remove_entry(ch, detail);
spin_unlock(&detail->hash_lock);
sunrpc_end_cache_remove_entry(ch, detail);
@@ -665,7 +677,7 @@ static void cache_limit_defers(void)
/* Consider removing either the first or the last */
if (cache_defer_cnt > DFR_MAX) {
- if (prandom_u32() & 1)
+ if (prandom_u32_max(2))
discard = list_entry(cache_defer_list.next,
struct cache_deferred_req, recent);
else
@@ -678,16 +690,30 @@ static void cache_limit_defers(void)
discard->revisit(discard, 1);
}
+#if IS_ENABLED(CONFIG_FAIL_SUNRPC)
+static inline bool cache_defer_immediately(void)
+{
+ return !fail_sunrpc.ignore_cache_wait &&
+ should_fail(&fail_sunrpc.attr, 1);
+}
+#else
+static inline bool cache_defer_immediately(void)
+{
+ return false;
+}
+#endif
+
/* Return true if and only if a deferred request is queued. */
static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
{
struct cache_deferred_req *dreq;
- if (req->thread_wait) {
+ if (!cache_defer_immediately()) {
cache_wait_req(req, item);
if (!test_bit(CACHE_PENDING, &item->flags))
return false;
}
+
dreq = req->defer(req);
if (dreq == NULL)
return false;
@@ -768,7 +794,6 @@ void cache_clean_deferred(void *owner)
*/
static DEFINE_SPINLOCK(queue_lock);
-static DEFINE_MUTEX(queue_io_mutex);
struct cache_queue {
struct list_head list;
@@ -794,7 +819,7 @@ static int cache_request(struct cache_detail *detail,
detail->cache_request(detail, crq->item, &bp, &len);
if (len < 0)
- return -EAGAIN;
+ return -E2BIG;
return PAGE_SIZE - len;
}
@@ -896,44 +921,26 @@ static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
return ret;
}
-static ssize_t cache_slow_downcall(const char __user *buf,
- size_t count, struct cache_detail *cd)
-{
- static char write_buf[8192]; /* protected by queue_io_mutex */
- ssize_t ret = -EINVAL;
-
- if (count >= sizeof(write_buf))
- goto out;
- mutex_lock(&queue_io_mutex);
- ret = cache_do_downcall(write_buf, buf, count, cd);
- mutex_unlock(&queue_io_mutex);
-out:
- return ret;
-}
-
static ssize_t cache_downcall(struct address_space *mapping,
const char __user *buf,
size_t count, struct cache_detail *cd)
{
- struct page *page;
- char *kaddr;
+ char *write_buf;
ssize_t ret = -ENOMEM;
- if (count >= PAGE_SIZE)
- goto out_slow;
+ if (count >= 32768) { /* 32k is max userland buffer, lets check anyway */
+ ret = -EINVAL;
+ goto out;
+ }
- page = find_or_create_page(mapping, 0, GFP_KERNEL);
- if (!page)
- goto out_slow;
+ write_buf = kvmalloc(count + 1, GFP_KERNEL);
+ if (!write_buf)
+ goto out;
- kaddr = kmap(page);
- ret = cache_do_downcall(kaddr, buf, count, cd);
- kunmap(page);
- unlock_page(page);
- put_page(page);
+ ret = cache_do_downcall(write_buf, buf, count, cd);
+ kvfree(write_buf);
+out:
return ret;
-out_slow:
- return cache_slow_downcall(buf, count, cd);
}
static ssize_t cache_write(struct file *filp, const char __user *buf,
@@ -1195,20 +1202,12 @@ static bool cache_listeners_exist(struct cache_detail *detail)
*
* Each request is at most one page long.
*/
-int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
+static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
{
-
char *buf;
struct cache_request *crq;
int ret = 0;
- if (!detail->cache_request)
- return -EINVAL;
-
- if (!cache_listeners_exist(detail)) {
- warn_no_listener(detail);
- return -EINVAL;
- }
if (test_bit(CACHE_CLEANED, &h->flags))
/* Too late to make an upcall */
return -EAGAIN;
@@ -1231,6 +1230,7 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
if (test_bit(CACHE_PENDING, &h->flags)) {
crq->item = cache_get(h);
list_add_tail(&crq->q.list, &detail->queue);
+ trace_cache_entry_upcall(detail, h);
} else
/* Lost a race, no longer PENDING, so don't enqueue */
ret = -EAGAIN;
@@ -1242,8 +1242,27 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
}
return ret;
}
+
+int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
+{
+ if (test_and_set_bit(CACHE_PENDING, &h->flags))
+ return 0;
+ return cache_pipe_upcall(detail, h);
+}
EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
+int sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail,
+ struct cache_head *h)
+{
+ if (!cache_listeners_exist(detail)) {
+ warn_no_listener(detail);
+ trace_cache_entry_no_listener(detail, h);
+ return -EINVAL;
+ }
+ return sunrpc_cache_pipe_upcall(detail, h);
+}
+EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall_timeout);
+
/*
* parse a message from user-space and pass it
* to an appropriate cache
@@ -1415,10 +1434,10 @@ static int c_show(struct seq_file *m, void *p)
cache_get(cp);
if (cache_check(cd, cp, NULL))
/* cache_check does a cache_put on failure */
- seq_printf(m, "# ");
+ seq_puts(m, "# ");
else {
if (cache_is_expired(cd, cp))
- seq_printf(m, "# ");
+ seq_puts(m, "# ");
cache_put(cp, cd);
}
@@ -1533,7 +1552,7 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
- struct cache_detail *cd = PDE_DATA(file_inode(filp));
+ struct cache_detail *cd = pde_data(file_inode(filp));
return cache_read(filp, buf, count, ppos, cd);
}
@@ -1541,14 +1560,14 @@ static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct cache_detail *cd = PDE_DATA(file_inode(filp));
+ struct cache_detail *cd = pde_data(file_inode(filp));
return cache_write(filp, buf, count, ppos, cd);
}
static __poll_t cache_poll_procfs(struct file *filp, poll_table *wait)
{
- struct cache_detail *cd = PDE_DATA(file_inode(filp));
+ struct cache_detail *cd = pde_data(file_inode(filp));
return cache_poll(filp, wait, cd);
}
@@ -1557,21 +1576,21 @@ static long cache_ioctl_procfs(struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return cache_ioctl(inode, filp, cmd, arg, cd);
}
static int cache_open_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return cache_open(inode, filp, cd);
}
static int cache_release_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return cache_release(inode, filp, cd);
}
@@ -1588,14 +1607,14 @@ static const struct proc_ops cache_channel_proc_ops = {
static int content_open_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return content_open(inode, filp, cd);
}
static int content_release_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return content_release(inode, filp, cd);
}
@@ -1609,14 +1628,14 @@ static const struct proc_ops content_proc_ops = {
static int open_flush_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return open_flush(inode, filp, cd);
}
static int release_flush_procfs(struct inode *inode, struct file *filp)
{
- struct cache_detail *cd = PDE_DATA(inode);
+ struct cache_detail *cd = pde_data(inode);
return release_flush(inode, filp, cd);
}
@@ -1624,7 +1643,7 @@ static int release_flush_procfs(struct inode *inode, struct file *filp)
static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
- struct cache_detail *cd = PDE_DATA(file_inode(filp));
+ struct cache_detail *cd = pde_data(file_inode(filp));
return read_flush(filp, buf, count, ppos, cd);
}
@@ -1633,7 +1652,7 @@ static ssize_t write_flush_procfs(struct file *filp,
const char __user *buf,
size_t count, loff_t *ppos)
{
- struct cache_detail *cd = PDE_DATA(file_inode(filp));
+ struct cache_detail *cd = pde_data(file_inode(filp));
return write_flush(filp, buf, count, ppos, cd);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.