v4.19.13 snapshot.
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
new file mode 100644
index 0000000..109fbe5
--- /dev/null
+++ b/net/sunrpc/cache.c
@@ -0,0 +1,1856 @@
+/*
+ * 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 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;
+}
+
+struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
+ struct cache_head *key, int hash)
+{
+ struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;
+ struct hlist_head *head;
+
+ head = &detail->hash_table[hash];
+
+ read_lock(&detail->hash_lock);
+
+ 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. */
+ break;
+ cache_get(tmp);
+ read_unlock(&detail->hash_lock);
+ return tmp;
+ }
+ }
+ read_unlock(&detail->hash_lock);
+ /* Didn't find anything, insert an empty entry */
+
+ 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);
+
+ write_lock(&detail->hash_lock);
+
+ /* check if entry appeared while we slept */
+ hlist_for_each_entry(tmp, head, cache_list) {
+ if (detail->match(tmp, key)) {
+ if (cache_is_expired(detail, tmp)) {
+ hlist_del_init(&tmp->cache_list);
+ detail->entries --;
+ freeme = tmp;
+ break;
+ }
+ cache_get(tmp);
+ write_unlock(&detail->hash_lock);
+ cache_put(new, detail);
+ return tmp;
+ }
+ }
+
+ hlist_add_head(&new->cache_list, head);
+ detail->entries++;
+ cache_get(new);
+ write_unlock(&detail->hash_lock);
+
+ if (freeme)
+ cache_put(freeme, detail);
+ return new;
+}
+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,
+ 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)) {
+ write_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);
+ write_unlock(&detail->hash_lock);
+ cache_fresh_unlocked(old, detail);
+ return old;
+ }
+ write_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);
+
+ write_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);
+ write_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;
+
+ write_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;
+ }
+ write_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;
+ }
+ }
+ }
+
+ 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)
+{
+ rwlock_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);
+ write_lock(&cd->hash_lock);
+ if (current_detail == cd)
+ current_detail = NULL;
+ list_del_init(&cd->others);
+ write_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(¤t_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;
+
+ write_lock(¤t_detail->hash_lock);
+
+ /* Ok, now to clean this strand */
+
+ head = ¤t_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(&ch->cache_list);
+ current_detail->entries--;
+ rv = 1;
+ break;
+ }
+
+ write_unlock(¤t_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;
+
+ write_lock(&detail->hash_lock);
+ if (!detail->entries) {
+ write_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(&ch->cache_list);
+ detail->entries--;
+
+ set_bit(CACHE_CLEANED, &ch->flags);
+ write_unlock(&detail->hash_lock);
+ cache_fresh_unlocked(ch, detail);
+ cache_put(ch, detail);
+ write_lock(&detail->hash_lock);
+ }
+ }
+ write_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
+ */
+
+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 = m->private;
+
+ read_lock(&cd->hash_lock);
+ if (!n--)
+ return SEQ_START_TOKEN;
+ hash = n >> 32;
+ entry = n & ((1LL<<32) - 1);
+
+ hlist_for_each_entry(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(cd->hash_table[hash].first,
+ struct cache_head, cache_list);
+}
+EXPORT_SYMBOL_GPL(cache_seq_start);
+
+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(ch->cache_list.next,
+ 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(cd->hash_table[hash].first,
+ struct cache_head, cache_list);
+}
+EXPORT_SYMBOL_GPL(cache_seq_next);
+
+void cache_seq_stop(struct seq_file *m, void *p)
+ __releases(cd->hash_lock)
+{
+ 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 = 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,
+ .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 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)
+{
+ write_lock(&cd->hash_lock);
+ if (!hlist_unhashed(&h->cache_list)){
+ hlist_del_init(&h->cache_list);
+ cd->entries--;
+ write_unlock(&cd->hash_lock);
+ cache_put(h, cd);
+ } else
+ write_unlock(&cd->hash_lock);
+}
+EXPORT_SYMBOL_GPL(sunrpc_cache_unhash);