From bc74b4f5e63a09fb78e245794a0de1e5a2716bbe Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 9 Aug 2009 15:14:29 -0400 Subject: SUNRPC: Allow the cache_detail to specify alternative upcall mechanisms For events that are rare, such as referral DNS lookups, it makes limited sense to have a daemon constantly listening for upcalls on a channel. An alternative in those cases might simply be to run the app that fills the cache using call_usermodehelper_exec() and friends. The following patch allows the cache_detail to specify alternative upcall mechanisms for these particular cases. Signed-off-by: Trond Myklebust --- net/sunrpc/cache.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) (limited to 'net/sunrpc/cache.c') diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index c8e7d2d0726..e438352bed7 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -176,7 +176,13 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, } EXPORT_SYMBOL_GPL(sunrpc_cache_update); -static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h); +static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) +{ + if (!cd->cache_upcall) + return -EINVAL; + return cd->cache_upcall(cd, h); +} + /* * This is the generic cache management routine for all * the authentication caches. @@ -322,7 +328,7 @@ static int create_cache_proc_entries(struct cache_detail *cd) if (p == NULL) goto out_nomem; - if (cd->cache_request || cd->cache_parse) { + if (cd->cache_upcall || cd->cache_parse) { p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, cd->proc_ent, &cache_file_operations, cd); cd->channel_ent = p; @@ -1080,10 +1086,16 @@ static void warn_no_listener(struct cache_detail *detail) } /* - * register an upcall request to user-space. + * 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. */ -static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) +int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, + void (*cache_request)(struct cache_detail *, + struct cache_head *, + char **, + int *)) { char *buf; @@ -1091,9 +1103,6 @@ static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) char *bp; int len; - if (detail->cache_request == NULL) - return -EINVAL; - if (atomic_read(&detail->readers) == 0 && detail->last_close < get_seconds() - 30) { warn_no_listener(detail); @@ -1112,7 +1121,7 @@ static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) bp = buf; len = PAGE_SIZE; - detail->cache_request(detail, h, &bp, &len); + cache_request(detail, h, &bp, &len); if (len < 0) { kfree(buf); @@ -1130,6 +1139,7 @@ static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) wake_up(&queue_wait); return 0; } +EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); /* * parse a message from user-space and pass it -- cgit v1.2.3