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linux_dsm_epyc7002/net/sunrpc/cache.c
NeilBrown 9d69338c8c sunrpc/cache: handle missing listeners better. 
If no handler (such as rpc.mountd) has opened
a cache 'channel', the sunrpc cache responds to
all lookup requests with -ENOENT.  This is particularly
important for the auth.unix.gid cache which is
optional.

If the channel was open briefly and an upcall was written to it,
this upcall remains pending even when the handler closes the
channel.  When an upcall is pending, the code currently
doesn't check if there are still listeners, it only performs
that check before sending an upcall.

As the cache treads a recently closes channel (closed less than
30 seconds ago) as "potentially still open", there is a
reasonable sized window when a request can become pending
in a closed channel, and thereby block lookups indefinitely.

This can easily be demonstrated by running
  cat /proc/net/rpc/auth.unix.gid/channel

and then trying to mount an NFS filesystem from this host.  It
will block indefinitely (unless mountd is run with --manage-gids,
or krb5 is used).

When cache_check() finds that an upcall is pending, it should
perform the "cache_listeners_exist()" exist test.  If no
listeners do exist, the request should be negated.

With this change in place, there can still be a 30second wait on
mount, until the cache gives up waiting for a handler to come
back, but this is much better than an indefinite wait.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-24 09:46:34 -04:00

1899 lines
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/*
* net/sunrpc/cache.c
*
* Generic code for various authentication-related caches
* used by sunrpc clients and servers.
*
* Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au>
*
* Released under terms in GPL version 2. See COPYING.
*
*/
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/string_helpers.h>
#include <linux/uaccess.h>
#include <linux/poll.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/net.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <asm/ioctls.h>
#include <linux/sunrpc/types.h>
#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 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)
{
time_t now = seconds_since_boot();
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;
}
static inline int cache_is_valid(struct cache_head *h);
static void cache_fresh_locked(struct cache_head *head, time_t expiry,
struct cache_detail *detail);
static void cache_fresh_unlocked(struct cache_head *head,
struct cache_detail *detail);
static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
struct cache_head *key,
int hash)
{
struct hlist_head *head = &detail->hash_table[hash];
struct cache_head *tmp;
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;
}
}
rcu_read_unlock();
return NULL;
}
static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
struct cache_head *key,
int hash)
{
struct cache_head *new, *tmp, *freeme = NULL;
struct hlist_head *head = &detail->hash_table[hash];
new = detail->alloc();
if (!new)
return NULL;
/* must fully initialise 'new', else
* we might get lose if we need to
* cache_put it soon.
*/
cache_init(new, detail);
detail->init(new, key);
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)) {
hlist_del_init_rcu(&tmp->cache_list);
detail->entries --;
if (cache_is_valid(tmp) == -EAGAIN)
set_bit(CACHE_NEGATIVE, &tmp->flags);
cache_fresh_locked(tmp, 0, detail);
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);
detail->entries++;
cache_get(new);
spin_unlock(&detail->hash_lock);
if (freeme) {
cache_fresh_unlocked(freeme, detail);
cache_put(freeme, detail);
}
return new;
}
struct cache_head *sunrpc_cache_lookup_rcu(struct cache_detail *detail,
struct cache_head *key, int hash)
{
struct cache_head *ret;
ret = sunrpc_cache_find_rcu(detail, key, hash);
if (ret)
return ret;
/* Didn't find anything, insert an empty entry */
return sunrpc_cache_add_entry(detail, key, hash);
}
EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu);
static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
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 = now;
smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
set_bit(CACHE_VALID, &head->flags);
}
static void cache_fresh_unlocked(struct cache_head *head,
struct cache_detail *detail)
{
if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
cache_revisit_request(head);
cache_dequeue(detail, head);
}
}
struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
struct cache_head *new, struct cache_head *old, int hash)
{
/* The 'old' entry is to be replaced by 'new'.
* If 'old' is not VALID, we update it directly,
* otherwise we need to replace it
*/
struct cache_head *tmp;
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_fresh_locked(old, new->expiry_time, detail);
spin_unlock(&detail->hash_lock);
cache_fresh_unlocked(old, detail);
return old;
}
spin_unlock(&detail->hash_lock);
}
/* We need to insert a new entry */
tmp = detail->alloc();
if (!tmp) {
cache_put(old, detail);
return NULL;
}
cache_init(tmp, 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);
hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
detail->entries++;
cache_get(tmp);
cache_fresh_locked(tmp, new->expiry_time, detail);
cache_fresh_locked(old, 0, detail);
spin_unlock(&detail->hash_lock);
cache_fresh_unlocked(tmp, detail);
cache_fresh_unlocked(old, detail);
cache_put(old, detail);
return tmp;
}
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))
return -EAGAIN;
else {
/* entry is valid */
if (test_bit(CACHE_NEGATIVE, &h->flags))
return -ENOENT;
else {
/*
* In combination with write barrier in
* sunrpc_cache_update, ensures that anyone
* using the cache entry after this sees the
* updated contents:
*/
smp_rmb();
return 0;
}
}
}
static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
{
int rv;
spin_lock(&detail->hash_lock);
rv = cache_is_valid(h);
if (rv == -EAGAIN) {
set_bit(CACHE_NEGATIVE, &h->flags);
cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
detail);
rv = -ENOENT;
}
spin_unlock(&detail->hash_lock);
cache_fresh_unlocked(h, detail);
return rv;
}
/*
* This is the generic cache management routine for all
* the authentication caches.
* It checks the currency of a cache item and will (later)
* initiate an upcall to fill it if needed.
*
*
* Returns 0 if the cache_head can be used, or cache_puts it and returns
* -EAGAIN if upcall is pending and request has been queued
* -ETIMEDOUT if upcall failed or request could not be queue or
* upcall completed but item is still invalid (implying that
* the cache item has been replaced with a newer one).
* -ENOENT if cache entry was negative
*/
int cache_check(struct cache_detail *detail,
struct cache_head *h, struct cache_req *rqstp)
{
int rv;
long refresh_age, age;
/* First decide return status as best we can */
rv = cache_is_valid(h);
/* now see if we want to start an upcall */
refresh_age = (h->expiry_time - h->last_refresh);
age = seconds_since_boot() - h->last_refresh;
if (rqstp == NULL) {
if (rv == -EAGAIN)
rv = -ENOENT;
} else if (rv == -EAGAIN ||
(h->expiry_time != 0 && age > refresh_age/2)) {
dprintk("RPC: Want update, refage=%ld, age=%ld\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))
rv = try_to_negate_entry(detail, h);
}
if (rv == -EAGAIN) {
if (!cache_defer_req(rqstp, h)) {
/*
* Request was not deferred; handle it as best
* we can ourselves:
*/
rv = cache_is_valid(h);
if (rv == -EAGAIN)
rv = -ETIMEDOUT;
}
}
if (rv)
cache_put(h, detail);
return rv;
}
EXPORT_SYMBOL_GPL(cache_check);
/*
* caches need to be periodically cleaned.
* For this we maintain a list of cache_detail and
* a current pointer into that list and into the table
* for that entry.
*
* Each time cache_clean is called it finds the next non-empty entry
* in the current table and walks the list in that entry
* looking for entries that can be removed.
*
* An entry gets removed if:
* - The expiry is before current time
* - The last_refresh time is before the flush_time for that cache
*
* later we might drop old entries with non-NEVER expiry if that table
* is getting 'full' for some definition of 'full'
*
* The question of "how often to scan a table" is an interesting one
* and is answered in part by the use of the "nextcheck" field in the
* cache_detail.
* When a scan of a table begins, the nextcheck field is set to a time
* that is well into the future.
* While scanning, if an expiry time is found that is earlier than the
* current nextcheck time, nextcheck is set to that expiry time.
* If the flush_time is ever set to a time earlier than the nextcheck
* time, the nextcheck time is then set to that flush_time.
*
* A table is then only scanned if the current time is at least
* the nextcheck time.
*
*/
static LIST_HEAD(cache_list);
static DEFINE_SPINLOCK(cache_list_lock);
static struct cache_detail *current_detail;
static int current_index;
static void do_cache_clean(struct work_struct *work);
static struct delayed_work cache_cleaner;
void sunrpc_init_cache_detail(struct cache_detail *cd)
{
spin_lock_init(&cd->hash_lock);
INIT_LIST_HEAD(&cd->queue);
spin_lock(&cache_list_lock);
cd->nextcheck = 0;
cd->entries = 0;
atomic_set(&cd->readers, 0);
cd->last_close = 0;
cd->last_warn = -1;
list_add(&cd->others, &cache_list);
spin_unlock(&cache_list_lock);
/* start the cleaning process */
queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0);
}
EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
void sunrpc_destroy_cache_detail(struct cache_detail *cd)
{
cache_purge(cd);
spin_lock(&cache_list_lock);
spin_lock(&cd->hash_lock);
if (current_detail == cd)
current_detail = NULL;
list_del_init(&cd->others);
spin_unlock(&cd->hash_lock);
spin_unlock(&cache_list_lock);
if (list_empty(&cache_list)) {
/* module must be being unloaded so its safe to kill the worker */
cancel_delayed_work_sync(&cache_cleaner);
}
}
EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
/* clean cache tries to find something to clean
* and cleans it.
* It returns 1 if it cleaned something,
* 0 if it didn't find anything this time
* -1 if it fell off the end of the list.
*/
static int cache_clean(void)
{
int rv = 0;
struct list_head *next;
spin_lock(&cache_list_lock);
/* find a suitable table if we don't already have one */
while (current_detail == NULL ||
current_index >= current_detail->hash_size) {
if (current_detail)
next = current_detail->others.next;
else
next = cache_list.next;
if (next == &cache_list) {
current_detail = NULL;
spin_unlock(&cache_list_lock);
return -1;
}
current_detail = list_entry(next, struct cache_detail, others);
if (current_detail->nextcheck > seconds_since_boot())
current_index = current_detail->hash_size;
else {
current_index = 0;
current_detail->nextcheck = seconds_since_boot()+30*60;
}
}
/* find a non-empty bucket in the table */
while (current_detail &&
current_index < current_detail->hash_size &&
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 = NULL;
struct cache_detail *d;
struct hlist_head *head;
struct hlist_node *tmp;
spin_lock(&current_detail->hash_lock);
/* Ok, now to clean this strand */
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;
hlist_del_init_rcu(&ch->cache_list);
current_detail->entries--;
rv = 1;
break;
}
spin_unlock(&current_detail->hash_lock);
d = current_detail;
if (!ch)
current_index ++;
spin_unlock(&cache_list_lock);
if (ch) {
set_bit(CACHE_CLEANED, &ch->flags);
cache_fresh_unlocked(ch, d);
cache_put(ch, d);
}
} else
spin_unlock(&cache_list_lock);
return rv;
}
/*
* We want to regularly clean the cache, so we need to schedule some work ...
*/
static void do_cache_clean(struct work_struct *work)
{
int delay = 5;
if (cache_clean() == -1)
delay = round_jiffies_relative(30*HZ);
if (list_empty(&cache_list))
delay = 0;
if (delay)
queue_delayed_work(system_power_efficient_wq,
&cache_cleaner, delay);
}
/*
* Clean all caches promptly. This just calls cache_clean
* repeatedly until we are sure that every cache has had a chance to
* be fully cleaned
*/
void cache_flush(void)
{
while (cache_clean() != -1)
cond_resched();
while (cache_clean() != -1)
cond_resched();
}
EXPORT_SYMBOL_GPL(cache_flush);
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);
if (!detail->entries) {
spin_unlock(&detail->hash_lock);
return;
}
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) {
hlist_del_init_rcu(&ch->cache_list);
detail->entries--;
set_bit(CACHE_CLEANED, &ch->flags);
spin_unlock(&detail->hash_lock);
cache_fresh_unlocked(ch, detail);
cache_put(ch, detail);
spin_lock(&detail->hash_lock);
}
}
spin_unlock(&detail->hash_lock);
}
EXPORT_SYMBOL_GPL(cache_purge);
/*
* Deferral and Revisiting of Requests.
*
* If a cache lookup finds a pending entry, we
* need to defer the request and revisit it later.
* All deferred requests are stored in a hash table,
* indexed by "struct cache_head *".
* As it may be wasteful to store a whole request
* structure, we allow the request to provide a
* deferred form, which must contain a
* 'struct cache_deferred_req'
* This cache_deferred_req contains a method to allow
* it to be revisited when cache info is available
*/
#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
#define DFR_MAX 300 /* ??? */
static DEFINE_SPINLOCK(cache_defer_lock);
static LIST_HEAD(cache_defer_list);
static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
static int cache_defer_cnt;
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)
{
int hash = DFR_HASH(item);
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);
__hash_deferred_req(dreq, item);
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 (prandom_u32() & 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)
discard->revisit(discard, 1);
}
/* 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) {
cache_wait_req(req, item);
if (!test_bit(CACHE_PENDING, &item->flags))
return false;
}
dreq = req->defer(req);
if (dreq == NULL)
return false;
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();
return true;
}
static void cache_revisit_request(struct cache_head *item)
{
struct cache_deferred_req *dreq;
struct list_head pending;
struct hlist_node *tmp;
int hash = DFR_HASH(item);
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
hlist_for_each_entry_safe(dreq, 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)) {
dreq = list_entry(pending.next, struct cache_deferred_req, recent);
list_del_init(&dreq->recent);
dreq->revisit(dreq, 0);
}
}
void cache_clean_deferred(void *owner)
{
struct cache_deferred_req *dreq, *tmp;
struct list_head pending;
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
if (dreq->owner == owner) {
__unhash_deferred_req(dreq);
list_add(&dreq->recent, &pending);
}
}
spin_unlock(&cache_defer_lock);
while (!list_empty(&pending)) {
dreq = list_entry(pending.next, struct cache_deferred_req, recent);
list_del_init(&dreq->recent);
dreq->revisit(dreq, 1);
}
}
/*
* communicate with user-space
*
* We have a magic /proc file - /proc/net/rpc/<cachename>/channel.
* On read, you get a full request, or block.
* On write, an update request is processed.
* Poll works if anything to read, and always allows write.
*
* Implemented by linked list of requests. Each open file has
* a ->private that also exists in this list. New requests are added
* to the end and may wakeup and preceding readers.
* New readers are added to the head. If, on read, an item is found with
* CACHE_UPCALLING clear, we free it from the list.
*
*/
static DEFINE_SPINLOCK(queue_lock);
static DEFINE_MUTEX(queue_io_mutex);
struct cache_queue {
struct list_head list;
int reader; /* if 0, then request */
};
struct cache_request {
struct cache_queue q;
struct cache_head *item;
char * buf;
int len;
int readers;
};
struct cache_reader {
struct cache_queue q;
int offset; /* if non-0, we have a refcnt on next request */
};
static int cache_request(struct cache_detail *detail,
struct cache_request *crq)
{
char *bp = crq->buf;
int len = PAGE_SIZE;
detail->cache_request(detail, crq->item, &bp, &len);
if (len < 0)
return -EAGAIN;
return PAGE_SIZE - len;
}
static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
loff_t *ppos, struct cache_detail *cd)
{
struct cache_reader *rp = filp->private_data;
struct cache_request *rq;
struct inode *inode = file_inode(filp);
int err;
if (count == 0)
return 0;
inode_lock(inode); /* protect against multiple concurrent
* readers on this file */
again:
spin_lock(&queue_lock);
/* need to find next request */
while (rp->q.list.next != &cd->queue &&
list_entry(rp->q.list.next, struct cache_queue, list)
->reader) {
struct list_head *next = rp->q.list.next;
list_move(&rp->q.list, next);
}
if (rp->q.list.next == &cd->queue) {
spin_unlock(&queue_lock);
inode_unlock(inode);
WARN_ON_ONCE(rp->offset);
return 0;
}
rq = container_of(rp->q.list.next, struct cache_request, q.list);
WARN_ON_ONCE(rq->q.reader);
if (rp->offset == 0)
rq->readers++;
spin_unlock(&queue_lock);
if (rq->len == 0) {
err = cache_request(cd, rq);
if (err < 0)
goto out;
rq->len = err;
}
if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
err = -EAGAIN;
spin_lock(&queue_lock);
list_move(&rp->q.list, &rq->q.list);
spin_unlock(&queue_lock);
} else {
if (rp->offset + count > rq->len)
count = rq->len - rp->offset;
err = -EFAULT;
if (copy_to_user(buf, rq->buf + rp->offset, count))
goto out;
rp->offset += count;
if (rp->offset >= rq->len) {
rp->offset = 0;
spin_lock(&queue_lock);
list_move(&rp->q.list, &rq->q.list);
spin_unlock(&queue_lock);
}
err = 0;
}
out:
if (rp->offset == 0) {
/* need to release rq */
spin_lock(&queue_lock);
rq->readers--;
if (rq->readers == 0 &&
!test_bit(CACHE_PENDING, &rq->item->flags)) {
list_del(&rq->q.list);
spin_unlock(&queue_lock);
cache_put(rq->item, cd);
kfree(rq->buf);
kfree(rq);
} else
spin_unlock(&queue_lock);
}
if (err == -EAGAIN)
goto again;
inode_unlock(inode);
return err ? err : count;
}
static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
size_t count, struct cache_detail *cd)
{
ssize_t ret;
if (count == 0)
return -EINVAL;
if (copy_from_user(kaddr, buf, count))
return -EFAULT;
kaddr[count] = '\0';
ret = cd->cache_parse(cd, kaddr, count);
if (!ret)
ret = count;
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;
ssize_t ret = -ENOMEM;
if (count >= PAGE_SIZE)
goto out_slow;
page = find_or_create_page(mapping, 0, GFP_KERNEL);
if (!page)
goto out_slow;
kaddr = kmap(page);
ret = cache_do_downcall(kaddr, buf, count, cd);
kunmap(page);
unlock_page(page);
put_page(page);
return ret;
out_slow:
return cache_slow_downcall(buf, count, cd);
}
static ssize_t cache_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
{
struct address_space *mapping = filp->f_mapping;
struct inode *inode = file_inode(filp);
ssize_t ret = -EINVAL;
if (!cd->cache_parse)
goto out;
inode_lock(inode);
ret = cache_downcall(mapping, buf, count, cd);
inode_unlock(inode);
out:
return ret;
}
static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
static __poll_t cache_poll(struct file *filp, poll_table *wait,
struct cache_detail *cd)
{
__poll_t mask;
struct cache_reader *rp = filp->private_data;
struct cache_queue *cq;
poll_wait(filp, &queue_wait, wait);
/* alway allow write */
mask = EPOLLOUT | EPOLLWRNORM;
if (!rp)
return mask;
spin_lock(&queue_lock);
for (cq= &rp->q; &cq->list != &cd->queue;
cq = list_entry(cq->list.next, struct cache_queue, list))
if (!cq->reader) {
mask |= EPOLLIN | EPOLLRDNORM;
break;
}
spin_unlock(&queue_lock);
return mask;
}
static int cache_ioctl(struct inode *ino, struct file *filp,
unsigned int cmd, unsigned long arg,
struct cache_detail *cd)
{
int len = 0;
struct cache_reader *rp = filp->private_data;
struct cache_queue *cq;
if (cmd != FIONREAD || !rp)
return -EINVAL;
spin_lock(&queue_lock);
/* only find the length remaining in current request,
* or the length of the next request
*/
for (cq= &rp->q; &cq->list != &cd->queue;
cq = list_entry(cq->list.next, struct cache_queue, list))
if (!cq->reader) {
struct cache_request *cr =
container_of(cq, struct cache_request, q);
len = cr->len - rp->offset;
break;
}
spin_unlock(&queue_lock);
return put_user(len, (int __user *)arg);
}
static int cache_open(struct inode *inode, struct file *filp,
struct cache_detail *cd)
{
struct cache_reader *rp = NULL;
if (!cd || !try_module_get(cd->owner))
return -EACCES;
nonseekable_open(inode, filp);
if (filp->f_mode & FMODE_READ) {
rp = kmalloc(sizeof(*rp), GFP_KERNEL);
if (!rp) {
module_put(cd->owner);
return -ENOMEM;
}
rp->offset = 0;
rp->q.reader = 1;
atomic_inc(&cd->readers);
spin_lock(&queue_lock);
list_add(&rp->q.list, &cd->queue);
spin_unlock(&queue_lock);
}
filp->private_data = rp;
return 0;
}
static int cache_release(struct inode *inode, struct file *filp,
struct cache_detail *cd)
{
struct cache_reader *rp = filp->private_data;
if (rp) {
spin_lock(&queue_lock);
if (rp->offset) {
struct cache_queue *cq;
for (cq= &rp->q; &cq->list != &cd->queue;
cq = list_entry(cq->list.next, struct cache_queue, list))
if (!cq->reader) {
container_of(cq, struct cache_request, q)
->readers--;
break;
}
rp->offset = 0;
}
list_del(&rp->q.list);
spin_unlock(&queue_lock);
filp->private_data = NULL;
kfree(rp);
cd->last_close = seconds_since_boot();
atomic_dec(&cd->readers);
}
module_put(cd->owner);
return 0;
}
static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
{
struct cache_queue *cq, *tmp;
struct cache_request *cr;
struct list_head dequeued;
INIT_LIST_HEAD(&dequeued);
spin_lock(&queue_lock);
list_for_each_entry_safe(cq, tmp, &detail->queue, list)
if (!cq->reader) {
cr = container_of(cq, struct cache_request, q);
if (cr->item != ch)
continue;
if (test_bit(CACHE_PENDING, &ch->flags))
/* Lost a race and it is pending again */
break;
if (cr->readers != 0)
continue;
list_move(&cr->q.list, &dequeued);
}
spin_unlock(&queue_lock);
while (!list_empty(&dequeued)) {
cr = list_entry(dequeued.next, struct cache_request, q.list);
list_del(&cr->q.list);
cache_put(cr->item, detail);
kfree(cr->buf);
kfree(cr);
}
}
/*
* Support routines for text-based upcalls.
* Fields are separated by spaces.
* Fields are either mangled to quote space tab newline slosh with slosh
* or a hexified with a leading \x
* Record is terminated with newline.
*
*/
void qword_add(char **bpp, int *lp, char *str)
{
char *bp = *bpp;
int len = *lp;
int ret;
if (len < 0) return;
ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
if (ret >= len) {
bp += len;
len = -1;
} else {
bp += ret;
len -= ret;
*bp++ = ' ';
len--;
}
*bpp = bp;
*lp = len;
}
EXPORT_SYMBOL_GPL(qword_add);
void qword_addhex(char **bpp, int *lp, char *buf, int blen)
{
char *bp = *bpp;
int len = *lp;
if (len < 0) return;
if (len > 2) {
*bp++ = '\\';
*bp++ = 'x';
len -= 2;
while (blen && len >= 2) {
bp = hex_byte_pack(bp, *buf++);
len -= 2;
blen--;
}
}
if (blen || len<1) len = -1;
else {
*bp++ = ' ';
len--;
}
*bpp = bp;
*lp = len;
}
EXPORT_SYMBOL_GPL(qword_addhex);
static void warn_no_listener(struct cache_detail *detail)
{
if (detail->last_warn != detail->last_close) {
detail->last_warn = detail->last_close;
if (detail->warn_no_listener)
detail->warn_no_listener(detail, detail->last_close != 0);
}
}
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.
*
* Each request is at most one page long.
*/
int sunrpc_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;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buf)
return -EAGAIN;
crq = kmalloc(sizeof (*crq), GFP_KERNEL);
if (!crq) {
kfree(buf);
return -EAGAIN;
}
crq->q.reader = 0;
crq->buf = buf;
crq->len = 0;
crq->readers = 0;
spin_lock(&queue_lock);
if (test_bit(CACHE_PENDING, &h->flags)) {
crq->item = cache_get(h);
list_add_tail(&crq->q.list, &detail->queue);
} else
/* Lost a race, no longer PENDING, so don't enqueue */
ret = -EAGAIN;
spin_unlock(&queue_lock);
wake_up(&queue_wait);
if (ret == -EAGAIN) {
kfree(buf);
kfree(crq);
}
return ret;
}
EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
/*
* parse a message from user-space and pass it
* to an appropriate cache
* Messages are, like requests, separated into fields by
* spaces and dequotes as \xHEXSTRING or embedded \nnn octal
*
* Message is
* reply cachename expiry key ... content....
*
* key and content are both parsed by cache
*/
int qword_get(char **bpp, char *dest, int bufsize)
{
/* return bytes copied, or -1 on error */
char *bp = *bpp;
int len = 0;
while (*bp == ' ') bp++;
if (bp[0] == '\\' && bp[1] == 'x') {
/* HEX STRING */
bp += 2;
while (len < bufsize - 1) {
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 {
/* text with \nnn octal quoting */
while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
if (*bp == '\\' &&
isodigit(bp[1]) && (bp[1] <= '3') &&
isodigit(bp[2]) &&
isodigit(bp[3])) {
int byte = (*++bp -'0');
bp++;
byte = (byte << 3) | (*bp++ - '0');
byte = (byte << 3) | (*bp++ - '0');
*dest++ = byte;
len++;
} else {
*dest++ = *bp++;
len++;
}
}
}
if (*bp != ' ' && *bp != '\n' && *bp != '\0')
return -1;
while (*bp == ' ') bp++;
*bpp = bp;
*dest = '\0';
return len;
}
EXPORT_SYMBOL_GPL(qword_get);
/*
* support /proc/net/rpc/$CACHENAME/content
* as a seqfile.
* We call ->cache_show passing NULL for the item to
* get a header, then pass each real item in the cache
*/
static void *__cache_seq_start(struct seq_file *m, loff_t *pos)
{
loff_t n = *pos;
unsigned int hash, entry;
struct cache_head *ch;
struct cache_detail *cd = m->private;
if (!n--)
return SEQ_START_TOKEN;
hash = n >> 32;
entry = n & ((1LL<<32) - 1);
hlist_for_each_entry_rcu(ch, &cd->hash_table[hash], cache_list)
if (!entry--)
return ch;
n &= ~((1LL<<32) - 1);
do {
hash++;
n += 1LL<<32;
} while(hash < cd->hash_size &&
hlist_empty(&cd->hash_table[hash]));
if (hash >= cd->hash_size)
return NULL;
*pos = n+1;
return hlist_entry_safe(rcu_dereference_raw(
hlist_first_rcu(&cd->hash_table[hash])),
struct cache_head, cache_list);
}
static 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 = m->private;
if (p == SEQ_START_TOKEN)
hash = 0;
else if (ch->cache_list.next == NULL) {
hash++;
*pos += 1LL<<32;
} else {
++*pos;
return hlist_entry_safe(rcu_dereference_raw(
hlist_next_rcu(&ch->cache_list)),
struct cache_head, cache_list);
}
*pos &= ~((1LL<<32) - 1);
while (hash < cd->hash_size &&
hlist_empty(&cd->hash_table[hash])) {
hash++;
*pos += 1LL<<32;
}
if (hash >= cd->hash_size)
return NULL;
++*pos;
return hlist_entry_safe(rcu_dereference_raw(
hlist_first_rcu(&cd->hash_table[hash])),
struct cache_head, cache_list);
}
EXPORT_SYMBOL_GPL(cache_seq_next);
void *cache_seq_start_rcu(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
rcu_read_lock();
return __cache_seq_start(m, pos);
}
EXPORT_SYMBOL_GPL(cache_seq_start_rcu);
void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos)
{
return cache_seq_next(file, p, pos);
}
EXPORT_SYMBOL_GPL(cache_seq_next_rcu);
void cache_seq_stop_rcu(struct seq_file *m, void *p)
__releases(RCU)
{
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(cache_seq_stop_rcu);
static int c_show(struct seq_file *m, void *p)
{
struct cache_head *cp = p;
struct cache_detail *cd = m->private;
if (p == SEQ_START_TOKEN)
return cd->cache_show(m, cd, NULL);
ifdebug(CACHE)
seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
convert_to_wallclock(cp->expiry_time),
kref_read(&cp->ref), cp->flags);
cache_get(cp);
if (cache_check(cd, cp, NULL))
/* cache_check does a cache_put on failure */
seq_printf(m, "# ");
else {
if (cache_is_expired(cd, cp))
seq_printf(m, "# ");
cache_put(cp, cd);
}
return cd->cache_show(m, cd, cp);
}
static const struct seq_operations cache_content_op = {
.start = cache_seq_start_rcu,
.next = cache_seq_next_rcu,
.stop = cache_seq_stop_rcu,
.show = c_show,
};
static int content_open(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
struct seq_file *seq;
int err;
if (!cd || !try_module_get(cd->owner))
return -EACCES;
err = seq_open(file, &cache_content_op);
if (err) {
module_put(cd->owner);
return err;
}
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(inode, file);
module_put(cd->owner);
return ret;
}
static int open_flush(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
if (!cd || !try_module_get(cd->owner))
return -EACCES;
return nonseekable_open(inode, file);
}
static int release_flush(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
module_put(cd->owner);
return 0;
}
static ssize_t read_flush(struct file *file, char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
{
char tbuf[22];
size_t len;
len = snprintf(tbuf, sizeof(tbuf), "%lu\n",
convert_to_wallclock(cd->flush_time));
return simple_read_from_buffer(buf, count, ppos, tbuf, len);
}
static ssize_t write_flush(struct file *file, const char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
{
char tbuf[20];
char *ep;
time_t now;
if (*ppos || count > sizeof(tbuf)-1)
return -EINVAL;
if (copy_from_user(tbuf, buf, count))
return -EFAULT;
tbuf[count] = 0;
simple_strtoul(tbuf, &ep, 0);
if (*ep && *ep != '\n')
return -EINVAL;
/* Note that while we check that 'buf' holds a valid number,
* we always ignore the value and just flush everything.
* Making use of the number leads to races.
*/
now = seconds_since_boot();
/* Always flush everything, so behave like cache_purge()
* Do this by advancing flush_time to the current time,
* or by one second if it has already reached the current time.
* Newly added cache entries will always have ->last_refresh greater
* that ->flush_time, so they don't get flushed prematurely.
*/
if (cd->flush_time >= now)
now = cd->flush_time + 1;
cd->flush_time = now;
cd->nextcheck = now;
cache_flush();
*ppos += count;
return count;
}
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));
return cache_read(filp, buf, count, ppos, cd);
}
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));
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));
return cache_poll(filp, wait, cd);
}
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);
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);
return cache_open(inode, filp, cd);
}
static int cache_release_procfs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = PDE_DATA(inode);
return cache_release(inode, filp, cd);
}
static const struct file_operations cache_file_operations_procfs = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = cache_read_procfs,
.write = cache_write_procfs,
.poll = cache_poll_procfs,
.unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
.open = cache_open_procfs,
.release = cache_release_procfs,
};
static int content_open_procfs(struct inode *inode, struct file *filp)
{
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);
return content_release(inode, filp, cd);
}
static const struct file_operations content_file_operations_procfs = {
.open = content_open_procfs,
.read = seq_read,
.llseek = seq_lseek,
.release = content_release_procfs,
};
static int open_flush_procfs(struct inode *inode, struct file *filp)
{
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);
return release_flush(inode, filp, cd);
}
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));
return read_flush(filp, buf, count, ppos, cd);
}
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));
return write_flush(filp, buf, count, ppos, cd);
}
static const struct file_operations cache_flush_operations_procfs = {
.open = open_flush_procfs,
.read = read_flush_procfs,
.write = write_flush_procfs,
.release = release_flush_procfs,
.llseek = no_llseek,
};
static void remove_cache_proc_entries(struct cache_detail *cd)
{
if (cd->procfs) {
proc_remove(cd->procfs);
cd->procfs = NULL;
}
}
#ifdef CONFIG_PROC_FS
static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
{
struct proc_dir_entry *p;
struct sunrpc_net *sn;
sn = net_generic(net, sunrpc_net_id);
cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc);
if (cd->procfs == NULL)
goto out_nomem;
p = proc_create_data("flush", S_IFREG | 0600,
cd->procfs, &cache_flush_operations_procfs, cd);
if (p == NULL)
goto out_nomem;
if (cd->cache_request || cd->cache_parse) {
p = proc_create_data("channel", S_IFREG | 0600, cd->procfs,
&cache_file_operations_procfs, cd);
if (p == NULL)
goto out_nomem;
}
if (cd->cache_show) {
p = proc_create_data("content", S_IFREG | 0400, cd->procfs,
&content_file_operations_procfs, cd);
if (p == NULL)
goto out_nomem;
}
return 0;
out_nomem:
remove_cache_proc_entries(cd);
return -ENOMEM;
}
#else /* CONFIG_PROC_FS */
static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
{
return 0;
}
#endif
void __init cache_initialize(void)
{
INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
}
int cache_register_net(struct cache_detail *cd, struct net *net)
{
int ret;
sunrpc_init_cache_detail(cd);
ret = create_cache_proc_entries(cd, net);
if (ret)
sunrpc_destroy_cache_detail(cd);
return ret;
}
EXPORT_SYMBOL_GPL(cache_register_net);
void cache_unregister_net(struct cache_detail *cd, struct net *net)
{
remove_cache_proc_entries(cd);
sunrpc_destroy_cache_detail(cd);
}
EXPORT_SYMBOL_GPL(cache_unregister_net);
struct cache_detail *cache_create_net(const 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 = kcalloc(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;
}
EXPORT_SYMBOL_GPL(cache_create_net);
void cache_destroy_net(struct cache_detail *cd, struct net *net)
{
kfree(cd->hash_table);
kfree(cd);
}
EXPORT_SYMBOL_GPL(cache_destroy_net);
static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
return cache_read(filp, buf, count, ppos, cd);
}
static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
return cache_write(filp, buf, count, ppos, cd);
}
static __poll_t cache_poll_pipefs(struct file *filp, poll_table *wait)
{
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
return cache_poll(filp, wait, cd);
}
static long cache_ioctl_pipefs(struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct cache_detail *cd = RPC_I(inode)->private;
return cache_ioctl(inode, filp, cmd, arg, cd);
}
static int cache_open_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return cache_open(inode, filp, cd);
}
static int cache_release_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return cache_release(inode, filp, cd);
}
const struct file_operations cache_file_operations_pipefs = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = cache_read_pipefs,
.write = cache_write_pipefs,
.poll = cache_poll_pipefs,
.unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
.open = cache_open_pipefs,
.release = cache_release_pipefs,
};
static int content_open_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return content_open(inode, filp, cd);
}
static int content_release_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return content_release(inode, filp, cd);
}
const struct file_operations content_file_operations_pipefs = {
.open = content_open_pipefs,
.read = seq_read,
.llseek = seq_lseek,
.release = content_release_pipefs,
};
static int open_flush_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return open_flush(inode, filp, cd);
}
static int release_flush_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return release_flush(inode, filp, cd);
}
static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
return read_flush(filp, buf, count, ppos, cd);
}
static ssize_t write_flush_pipefs(struct file *filp,
const char __user *buf,
size_t count, loff_t *ppos)
{
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
return write_flush(filp, buf, count, ppos, cd);
}
const struct file_operations cache_flush_operations_pipefs = {
.open = open_flush_pipefs,
.read = read_flush_pipefs,
.write = write_flush_pipefs,
.release = release_flush_pipefs,
.llseek = no_llseek,
};
int sunrpc_cache_register_pipefs(struct dentry *parent,
const char *name, umode_t umode,
struct cache_detail *cd)
{
struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
if (IS_ERR(dir))
return PTR_ERR(dir);
cd->pipefs = dir;
return 0;
}
EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
{
if (cd->pipefs) {
rpc_remove_cache_dir(cd->pipefs);
cd->pipefs = NULL;
}
}
EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h)
{
spin_lock(&cd->hash_lock);
if (!hlist_unhashed(&h->cache_list)){
hlist_del_init_rcu(&h->cache_list);
cd->entries--;
spin_unlock(&cd->hash_lock);
cache_put(h, cd);
} else
spin_unlock(&cd->hash_lock);
}
EXPORT_SYMBOL_GPL(sunrpc_cache_unhash);
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