diff options
Diffstat (limited to 'kernel/net/sunrpc/cache.c')
| -rw-r--r-- | kernel/net/sunrpc/cache.c | 1826 |
1 files changed, 1826 insertions, 0 deletions
diff --git a/kernel/net/sunrpc/cache.c b/kernel/net/sunrpc/cache.c new file mode 100644 index 000000000..2928afffb --- /dev/null +++ b/kernel/net/sunrpc/cache.c @@ -0,0 +1,1826 @@ +/* + * 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 <asm/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) +{ + time_t now = seconds_since_boot(); + h->next = NULL; + h->flags = 0; + kref_init(&h->ref); + h->expiry_time = now + CACHE_NEW_EXPIRY; + h->last_refresh = now; +} + +struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, + struct cache_head *key, int hash) +{ + struct cache_head **head, **hp; + struct cache_head *new = NULL, *freeme = NULL; + + head = &detail->hash_table[hash]; + + read_lock(&detail->hash_lock); + + for (hp=head; *hp != NULL ; hp = &(*hp)->next) { + struct cache_head *tmp = *hp; + 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->init(new, key); + + write_lock(&detail->hash_lock); + + /* check if entry appeared while we slept */ + for (hp=head; *hp != NULL ; hp = &(*hp)->next) { + struct cache_head *tmp = *hp; + if (detail->match(tmp, key)) { + if (cache_is_expired(detail, tmp)) { + *hp = tmp->next; + tmp->next = NULL; + detail->entries --; + freeme = tmp; + break; + } + cache_get(tmp); + write_unlock(&detail->hash_lock); + cache_put(new, detail); + return tmp; + } + } + new->next = *head; + *head = new; + 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) +{ + head->expiry_time = expiry; + head->last_refresh = seconds_since_boot(); + 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 **head; + 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); + 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->init(tmp, old); + head = &detail->hash_table[hash]; + + write_lock(&detail->hash_lock); + if (test_bit(CACHE_NEGATIVE, &new->flags)) + set_bit(CACHE_NEGATIVE, &tmp->flags); + else + detail->update(tmp, new); + tmp->next = *head; + *head = tmp; + detail->entries++; + cache_get(tmp); + cache_fresh_locked(tmp, new->expiry_time); + cache_fresh_locked(old, 0); + 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); + 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 */ + schedule_delayed_work(&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 (cd->entries || atomic_read(&cd->inuse)) { + write_unlock(&cd->hash_lock); + spin_unlock(&cache_list_lock); + goto out; + } + 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); + } + return; +out: + printk(KERN_ERR "RPC: failed to unregister %s cache\n", cd->name); +} +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 && + current_detail->hash_table[current_index] == NULL) + current_index++; + + /* find a cleanable entry in the bucket and clean it, or set to next bucket */ + + if (current_detail && current_index < current_detail->hash_size) { + struct cache_head *ch, **cp; + struct cache_detail *d; + + write_lock(¤t_detail->hash_lock); + + /* Ok, now to clean this strand */ + + cp = & current_detail->hash_table[current_index]; + for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { + if (current_detail->nextcheck > ch->expiry_time) + current_detail->nextcheck = ch->expiry_time+1; + if (!cache_is_expired(current_detail, ch)) + continue; + + *cp = ch->next; + ch->next = NULL; + 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) + schedule_delayed_work(&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) +{ + detail->flush_time = LONG_MAX; + detail->nextcheck = seconds_since_boot(); + cache_flush(); + detail->flush_time = 1; +} +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/sunrpc/<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; + + mutex_lock(&inode->i_mutex); /* 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); + mutex_unlock(&inode->i_mutex); + 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; + mutex_unlock(&inode->i_mutex); + 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_CACHE_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); + page_cache_release(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; + + mutex_lock(&inode->i_mutex); + ret = cache_downcall(mapping, buf, count, cd); + mutex_unlock(&inode->i_mutex); +out: + return ret; +} + +static DECLARE_WAIT_QUEUE_HEAD(queue_wait); + +static unsigned int cache_poll(struct file *filp, poll_table *wait, + struct cache_detail *cd) +{ + unsigned int mask; + struct cache_reader *rp = filp->private_data; + struct cache_queue *cq; + + poll_wait(filp, &queue_wait, wait); + + /* alway allow write */ + mask = POLLOUT | POLLWRNORM; + + 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 |= POLLIN | POLLRDNORM; + 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->item = cache_get(h); + crq->buf = buf; + crq->len = 0; + crq->readers = 0; + spin_lock(&queue_lock); + if (test_bit(CACHE_PENDING, &h->flags)) + 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) { + 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/sunrpc/cache/$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 + */ + +struct handle { + struct cache_detail *cd; +}; + +static void *c_start(struct seq_file *m, loff_t *pos) + __acquires(cd->hash_lock) +{ + loff_t n = *pos; + unsigned int hash, entry; + struct cache_head *ch; + struct cache_detail *cd = ((struct handle*)m->private)->cd; + + + read_lock(&cd->hash_lock); + if (!n--) + return SEQ_START_TOKEN; + hash = n >> 32; + entry = n & ((1LL<<32) - 1); + + for (ch=cd->hash_table[hash]; ch; ch=ch->next) + if (!entry--) + return ch; + n &= ~((1LL<<32) - 1); + do { + hash++; + n += 1LL<<32; + } while(hash < cd->hash_size && + cd->hash_table[hash]==NULL); + if (hash >= cd->hash_size) + return NULL; + *pos = n+1; + return cd->hash_table[hash]; +} + +static void *c_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct cache_head *ch = p; + int hash = (*pos >> 32); + struct cache_detail *cd = ((struct handle*)m->private)->cd; + + if (p == SEQ_START_TOKEN) + hash = 0; + else if (ch->next == NULL) { + hash++; + *pos += 1LL<<32; + } else { + ++*pos; + return ch->next; + } + *pos &= ~((1LL<<32) - 1); + while (hash < cd->hash_size && + cd->hash_table[hash] == NULL) { + hash++; + *pos += 1LL<<32; + } + if (hash >= cd->hash_size) + return NULL; + ++*pos; + return cd->hash_table[hash]; +} + +static void c_stop(struct seq_file *m, void *p) + __releases(cd->hash_lock) +{ + struct cache_detail *cd = ((struct handle*)m->private)->cd; + read_unlock(&cd->hash_lock); +} + +static int c_show(struct seq_file *m, void *p) +{ + struct cache_head *cp = p; + struct cache_detail *cd = ((struct handle*)m->private)->cd; + + 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), + atomic_read(&cp->ref.refcount), 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 = c_start, + .next = c_next, + .stop = c_stop, + .show = c_show, +}; + +static int content_open(struct inode *inode, struct file *file, + struct cache_detail *cd) +{ + struct handle *han; + + if (!cd || !try_module_get(cd->owner)) + return -EACCES; + han = __seq_open_private(file, &cache_content_op, sizeof(*han)); + if (han == NULL) { + module_put(cd->owner); + return -ENOMEM; + } + + han->cd = cd; + return 0; +} + +static int content_release(struct inode *inode, struct file *file, + struct cache_detail *cd) +{ + int ret = seq_release_private(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]; + unsigned long p = *ppos; + size_t len; + + snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time)); + len = strlen(tbuf); + if (p >= len) + return 0; + len -= p; + if (len > count) + len = count; + if (copy_to_user(buf, (void*)(tbuf+p), len)) + return -EFAULT; + *ppos += len; + return 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 *bp, *ep; + + 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; + + bp = tbuf; + cd->flush_time = get_expiry(&bp); + cd->nextcheck = seconds_since_boot(); + 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 unsigned int 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, struct net *net) +{ + struct sunrpc_net *sn; + + if (cd->u.procfs.proc_ent == NULL) + return; + if (cd->u.procfs.flush_ent) + remove_proc_entry("flush", cd->u.procfs.proc_ent); + if (cd->u.procfs.channel_ent) + remove_proc_entry("channel", cd->u.procfs.proc_ent); + if (cd->u.procfs.content_ent) + remove_proc_entry("content", cd->u.procfs.proc_ent); + cd->u.procfs.proc_ent = NULL; + sn = net_generic(net, sunrpc_net_id); + remove_proc_entry(cd->name, sn->proc_net_rpc); +} + +#ifdef CONFIG_PROC_FS +static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) +{ + struct proc_dir_entry *p; + struct sunrpc_net *sn; + + sn = net_generic(net, sunrpc_net_id); + cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc); + if (cd->u.procfs.proc_ent == NULL) + goto out_nomem; + cd->u.procfs.channel_ent = NULL; + cd->u.procfs.content_ent = NULL; + + p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, + cd->u.procfs.proc_ent, + &cache_flush_operations_procfs, cd); + cd->u.procfs.flush_ent = p; + if (p == NULL) + goto out_nomem; + + if (cd->cache_request || cd->cache_parse) { + p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, + cd->u.procfs.proc_ent, + &cache_file_operations_procfs, cd); + cd->u.procfs.channel_ent = p; + if (p == NULL) + goto out_nomem; + } + if (cd->cache_show) { + p = proc_create_data("content", S_IFREG|S_IRUSR, + cd->u.procfs.proc_ent, + &content_file_operations_procfs, cd); + cd->u.procfs.content_ent = p; + if (p == NULL) + goto out_nomem; + } + return 0; +out_nomem: + remove_cache_proc_entries(cd, net); + 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, net); + sunrpc_destroy_cache_detail(cd); +} +EXPORT_SYMBOL_GPL(cache_unregister_net); + +struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) +{ + struct cache_detail *cd; + + cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); + if (cd == NULL) + return ERR_PTR(-ENOMEM); + + cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), + GFP_KERNEL); + if (cd->hash_table == NULL) { + kfree(cd); + return ERR_PTR(-ENOMEM); + } + 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 unsigned int 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->u.pipefs.dir = dir; + return 0; +} +EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); + +void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) +{ + rpc_remove_cache_dir(cd->u.pipefs.dir); + cd->u.pipefs.dir = NULL; +} +EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); + |