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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 18:55:25 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 18:55:25 +0200 |
commit | 4390110fef9e5c64e10c6ca19d586932242c9a8a (patch) | |
tree | f2f26fe291c8b4e424b97ac57370b33e0c006568 /net/sunrpc/cache.c | |
parent | Merge branch 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs... (diff) | |
parent | svcrpc: svc_tcp_sendto XPT_DEAD check is redundant (diff) | |
download | linux-4390110fef9e5c64e10c6ca19d586932242c9a8a.tar.xz linux-4390110fef9e5c64e10c6ca19d586932242c9a8a.zip |
Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
svcrpc: assume svc_delete_xprt() called only once
svcrpc: never clear XPT_BUSY on dead xprt
nfsd4: fix connection allocation in sequence()
nfsd4: only require krb5 principal for NFSv4.0 callbacks
nfsd4: move minorversion to client
nfsd4: delay session removal till free_client
nfsd4: separate callback change and callback probe
nfsd4: callback program number is per-session
nfsd4: track backchannel connections
nfsd4: confirm only on succesful create_session
nfsd4: make backchannel sequence number per-session
nfsd4: use client pointer to backchannel session
nfsd4: move callback setup into session init code
nfsd4: don't cache seq_misordered replies
SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
SUNRPC: Use conventional switch statement when reclassifying sockets
sunrpc/xprtrdma: clean up workqueue usage
sunrpc: Turn list_for_each-s into the ..._entry-s
...
Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
Diffstat (limited to 'net/sunrpc/cache.c')
-rw-r--r-- | net/sunrpc/cache.c | 288 |
1 files changed, 201 insertions, 87 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 7dce81a926c5..e433e7580e27 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -33,15 +33,16 @@ #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 int cache_defer_req(struct cache_req *req, struct cache_head *item); +static void 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 = get_seconds(); + time_t now = seconds_since_boot(); h->next = NULL; h->flags = 0; kref_init(&h->ref); @@ -51,7 +52,7 @@ static void cache_init(struct cache_head *h) static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h) { - return (h->expiry_time < get_seconds()) || + return (h->expiry_time < seconds_since_boot()) || (detail->flush_time > h->last_refresh); } @@ -126,7 +127,7 @@ 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 = get_seconds(); + head->last_refresh = seconds_since_boot(); set_bit(CACHE_VALID, &head->flags); } @@ -237,7 +238,7 @@ int cache_check(struct cache_detail *detail, /* now see if we want to start an upcall */ refresh_age = (h->expiry_time - h->last_refresh); - age = get_seconds() - h->last_refresh; + age = seconds_since_boot() - h->last_refresh; if (rqstp == NULL) { if (rv == -EAGAIN) @@ -252,7 +253,7 @@ int cache_check(struct cache_detail *detail, cache_revisit_request(h); if (rv == -EAGAIN) { set_bit(CACHE_NEGATIVE, &h->flags); - cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY); + cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY); cache_fresh_unlocked(h, detail); rv = -ENOENT; } @@ -267,7 +268,8 @@ int cache_check(struct cache_detail *detail, } if (rv == -EAGAIN) { - if (cache_defer_req(rqstp, h) < 0) { + cache_defer_req(rqstp, h); + if (!test_bit(CACHE_PENDING, &h->flags)) { /* Request is not deferred */ rv = cache_is_valid(detail, h); if (rv == -EAGAIN) @@ -387,11 +389,11 @@ static int cache_clean(void) return -1; } current_detail = list_entry(next, struct cache_detail, others); - if (current_detail->nextcheck > get_seconds()) + if (current_detail->nextcheck > seconds_since_boot()) current_index = current_detail->hash_size; else { current_index = 0; - current_detail->nextcheck = get_seconds()+30*60; + current_detail->nextcheck = seconds_since_boot()+30*60; } } @@ -476,7 +478,7 @@ EXPORT_SYMBOL_GPL(cache_flush); void cache_purge(struct cache_detail *detail) { detail->flush_time = LONG_MAX; - detail->nextcheck = get_seconds(); + detail->nextcheck = seconds_since_boot(); cache_flush(); detail->flush_time = 1; } @@ -505,81 +507,155 @@ EXPORT_SYMBOL_GPL(cache_purge); static DEFINE_SPINLOCK(cache_defer_lock); static LIST_HEAD(cache_defer_list); -static struct list_head cache_defer_hash[DFR_HASHSIZE]; +static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; static int cache_defer_cnt; -static int cache_defer_req(struct cache_req *req, struct cache_head *item) +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) { - struct cache_deferred_req *dreq, *discard; int hash = DFR_HASH(item); - if (cache_defer_cnt >= DFR_MAX) { - /* too much in the cache, randomly drop this one, - * or continue and drop the oldest below - */ - if (net_random()&1) - return -ENOMEM; - } - dreq = req->defer(req); - if (dreq == NULL) - return -ENOMEM; + 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); - list_add(&dreq->recent, &cache_defer_list); - - if (cache_defer_hash[hash].next == NULL) - INIT_LIST_HEAD(&cache_defer_hash[hash]); - list_add(&dreq->hash, &cache_defer_hash[hash]); + __hash_deferred_req(dreq, item); - /* it is in, now maybe clean up */ - discard = NULL; - if (++cache_defer_cnt > DFR_MAX) { - discard = list_entry(cache_defer_list.prev, - struct cache_deferred_req, recent); - list_del_init(&discard->recent); - list_del_init(&discard->hash); - cache_defer_cnt--; + 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 (net_random() & 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) - /* there was one too many */ discard->revisit(discard, 1); +} - if (!test_bit(CACHE_PENDING, &item->flags)) { - /* must have just been validated... */ - cache_revisit_request(item); - return -EAGAIN; +static void 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; } - return 0; + dreq = req->defer(req); + if (dreq == NULL) + return; + 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(); } static void cache_revisit_request(struct cache_head *item) { struct cache_deferred_req *dreq; struct list_head pending; - - struct list_head *lp; + struct hlist_node *lp, *tmp; int hash = DFR_HASH(item); INIT_LIST_HEAD(&pending); spin_lock(&cache_defer_lock); - lp = cache_defer_hash[hash].next; - if (lp) { - while (lp != &cache_defer_hash[hash]) { - dreq = list_entry(lp, struct cache_deferred_req, hash); - lp = lp->next; - if (dreq->item == item) { - list_del_init(&dreq->hash); - list_move(&dreq->recent, &pending); - cache_defer_cnt--; - } + hlist_for_each_entry_safe(dreq, lp, 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)) { @@ -600,9 +676,8 @@ void cache_clean_deferred(void *owner) list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { if (dreq->owner == owner) { - list_del_init(&dreq->hash); - list_move(&dreq->recent, &pending); - cache_defer_cnt--; + __unhash_deferred_req(dreq); + list_add(&dreq->recent, &pending); } } spin_unlock(&cache_defer_lock); @@ -901,7 +976,7 @@ static int cache_release(struct inode *inode, struct file *filp, filp->private_data = NULL; kfree(rp); - cd->last_close = get_seconds(); + cd->last_close = seconds_since_boot(); atomic_dec(&cd->readers); } module_put(cd->owner); @@ -1014,6 +1089,23 @@ static void warn_no_listener(struct cache_detail *detail) } } +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. @@ -1032,10 +1124,9 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, char *bp; int len; - if (atomic_read(&detail->readers) == 0 && - detail->last_close < get_seconds() - 30) { - warn_no_listener(detail); - return -EINVAL; + if (!cache_listeners_exist(detail)) { + warn_no_listener(detail); + return -EINVAL; } buf = kmalloc(PAGE_SIZE, GFP_KERNEL); @@ -1094,13 +1185,19 @@ int qword_get(char **bpp, char *dest, int bufsize) if (bp[0] == '\\' && bp[1] == 'x') { /* HEX STRING */ bp += 2; - while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { - int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; - bp++; - byte <<= 4; - byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; - *dest++ = byte; - bp++; + 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 { @@ -1218,7 +1315,8 @@ static int c_show(struct seq_file *m, void *p) ifdebug(CACHE) seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", - cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags); + 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 */ @@ -1284,7 +1382,7 @@ static ssize_t read_flush(struct file *file, char __user *buf, unsigned long p = *ppos; size_t len; - sprintf(tbuf, "%lu\n", cd->flush_time); + sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time)); len = strlen(tbuf); if (p >= len) return 0; @@ -1302,19 +1400,20 @@ static ssize_t write_flush(struct file *file, const char __user *buf, struct cache_detail *cd) { char tbuf[20]; - char *ep; - long flushtime; + char *bp, *ep; + if (*ppos || count > sizeof(tbuf)-1) return -EINVAL; if (copy_from_user(tbuf, buf, count)) return -EFAULT; tbuf[count] = 0; - flushtime = simple_strtoul(tbuf, &ep, 0); + simple_strtoul(tbuf, &ep, 0); if (*ep && *ep != '\n') return -EINVAL; - cd->flush_time = flushtime; - cd->nextcheck = get_seconds(); + bp = tbuf; + cd->flush_time = get_expiry(&bp); + cd->nextcheck = seconds_since_boot(); cache_flush(); *ppos += count; @@ -1438,8 +1537,10 @@ static const struct file_operations cache_flush_operations_procfs = { .llseek = no_llseek, }; -static void remove_cache_proc_entries(struct cache_detail *cd) +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) @@ -1449,15 +1550,18 @@ static void remove_cache_proc_entries(struct cache_detail *cd) if (cd->u.procfs.content_ent) remove_proc_entry("content", cd->u.procfs.proc_ent); cd->u.procfs.proc_ent = NULL; - remove_proc_entry(cd->name, proc_net_rpc); + 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) +static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) { struct proc_dir_entry *p; + struct sunrpc_net *sn; - cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc); + 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; @@ -1488,11 +1592,11 @@ static int create_cache_proc_entries(struct cache_detail *cd) } return 0; out_nomem: - remove_cache_proc_entries(cd); + remove_cache_proc_entries(cd, net); return -ENOMEM; } #else /* CONFIG_PROC_FS */ -static int create_cache_proc_entries(struct cache_detail *cd) +static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) { return 0; } @@ -1503,23 +1607,33 @@ void __init cache_initialize(void) INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean); } -int cache_register(struct cache_detail *cd) +int cache_register_net(struct cache_detail *cd, struct net *net) { int ret; sunrpc_init_cache_detail(cd); - ret = create_cache_proc_entries(cd); + ret = create_cache_proc_entries(cd, net); if (ret) sunrpc_destroy_cache_detail(cd); return ret; } + +int cache_register(struct cache_detail *cd) +{ + return cache_register_net(cd, &init_net); +} EXPORT_SYMBOL_GPL(cache_register); -void cache_unregister(struct cache_detail *cd) +void cache_unregister_net(struct cache_detail *cd, struct net *net) { - remove_cache_proc_entries(cd); + remove_cache_proc_entries(cd, net); sunrpc_destroy_cache_detail(cd); } + +void cache_unregister(struct cache_detail *cd) +{ + cache_unregister_net(cd, &init_net); +} EXPORT_SYMBOL_GPL(cache_unregister); static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, |