| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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> |
| */ |
| |
| #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) |
| { |
| time64_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 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 void sunrpc_begin_cache_remove_entry(struct cache_head *ch, |
| struct cache_detail *cd) |
| { |
| /* Must be called under cd->hash_lock */ |
| hlist_del_init_rcu(&ch->cache_list); |
| set_bit(CACHE_CLEANED, &ch->flags); |
| cd->entries --; |
| } |
| |
| static void sunrpc_end_cache_remove_entry(struct cache_head *ch, |
| struct cache_detail *cd) |
| { |
| cache_fresh_unlocked(ch, cd); |
| cache_put(ch, cd); |
| } |
| |
| 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)) { |
| sunrpc_begin_cache_remove_entry(tmp, detail); |
| freeme = tmp; |
| break; |
| } |
| cache_get(tmp); |
| spin_unlock(&detail->hash_lock); |
| cache_put(new, detail); |
| return tmp; |
| } |
| } |
| |
| hlist_add_head_rcu(&new->cache_list, head); |
| detail->entries++; |
| cache_get(new); |
| spin_unlock(&detail->hash_lock); |
| |
| if (freeme) |
| sunrpc_end_cache_remove_entry(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, time64_t expiry, |
| struct cache_detail *detail) |
| { |
| time64_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; |
| time64_t 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=%lld, age=%lld\n", |
| refresh_age, age); |
| if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
| switch (cache_make_upcall(detail, h)) { |
| case -EINVAL: |
| rv = try_to_negate_entry(detail, h); |
| break; |
| case -EAGAIN: |
| cache_fresh_unlocked(h, detail); |
| break; |
| } |
| } else if (!cache_listeners_exist(detail)) |
| 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->writers, 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(¤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; |
| |
| spin_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; |
| |
| sunrpc_begin_cache_remove_entry(ch, current_detail); |
| rv = 1; |
| break; |
| } |
| |
| spin_unlock(¤t_detail->hash_lock); |
| d = current_detail; |
| if (!ch) |
| current_index ++; |
| spin_unlock(&cache_list_lock); |
| if (ch) |
| sunrpc_end_cache_remove_entry(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) { |
| sunrpc_begin_cache_remove_entry(ch, detail); |
| spin_unlock(&detail->hash_lock); |
| sunrpc_end_cache_remove_entry(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; |
| |
| spin_lock(&queue_lock); |
| list_add(&rp->q.list, &cd->queue); |
| spin_unlock(&queue_lock); |
| } |
| if (filp->f_mode & FMODE_WRITE) |
| atomic_inc(&cd->writers); |
| 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); |
| |
| } |
| if (filp->f_mode & FMODE_WRITE) { |
| atomic_dec(&cd->writers); |
| cd->last_close = seconds_since_boot(); |
| } |
| 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->writers)) |
| 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); |
| } |
| |
| 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=%lld 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), "%llu\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; |
| time64_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(); |
| |
| if (cd->flush) |
| cd->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 proc_ops cache_channel_proc_ops = { |
| .proc_lseek = no_llseek, |
| .proc_read = cache_read_procfs, |
| .proc_write = cache_write_procfs, |
| .proc_poll = cache_poll_procfs, |
| .proc_ioctl = cache_ioctl_procfs, /* for FIONREAD */ |
| .proc_open = cache_open_procfs, |
| .proc_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 proc_ops content_proc_ops = { |
| .proc_open = content_open_procfs, |
| .proc_read = seq_read, |
| .proc_lseek = seq_lseek, |
| .proc_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 proc_ops cache_flush_proc_ops = { |
| .proc_open = open_flush_procfs, |
| .proc_read = read_flush_procfs, |
| .proc_write = write_flush_procfs, |
| .proc_release = release_flush_procfs, |
| .proc_lseek = 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_proc_ops, 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_channel_proc_ops, cd); |
| if (p == NULL) |
| goto out_nomem; |
| } |
| if (cd->cache_show) { |
| p = proc_create_data("content", S_IFREG | 0400, cd->procfs, |
| &content_proc_ops, 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)){ |
| sunrpc_begin_cache_remove_entry(h, cd); |
| spin_unlock(&cd->hash_lock); |
| sunrpc_end_cache_remove_entry(h, cd); |
| } else |
| spin_unlock(&cd->hash_lock); |
| } |
| EXPORT_SYMBOL_GPL(sunrpc_cache_unhash); |