[PATCH 23/32] SUNRPC: Allow the cache_detail to specify alternative upcall mechanisms

Trond Myklebust
2009-08-19T23:40:57Z

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 <Trond.Myklebust@netapp.com>
---
fs/nfsd/export.c | 14 ++++++++++++--
fs/nfsd/nfs4idmap.c | 16 ++++++++++++++--
include/linux/sunrpc/cache.h | 13 ++++++++++---
net/sunrpc/auth_gss/svcauth_gss.c | 7 ++++++-
net/sunrpc/cache.c | 26 ++++++++++++++++++--------
net/sunrpc/svcauth_unix.c | 14 ++++++++++++--
6 files changed, 72 insertions(+), 18 deletions(-)

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index b92a276..d946264 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -85,6 +85,11 @@ static void expkey_request(struct cache_detail *cd,
(*bpp)[-1] = '\n';
}

+static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_pipe_upcall(cd, h, expkey_request);
+}
+
static struct svc_expkey *svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old);
static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *);
static struct cache_detail svc_expkey_cache;
@@ -259,7 +264,7 @@ static struct cache_detail svc_expkey_cache = {
.hash_table = expkey_table,
.name = "nfsd.fh",
.cache_put = expkey_put,
- .cache_request = expkey_request,
+ .cache_upcall = expkey_upcall,
.cache_parse = expkey_parse,
.cache_show = expkey_show,
.match = expkey_match,
@@ -355,6 +360,11 @@ static void svc_export_request(struct cache_detail *cd,
(*bpp)[-1] = '\n';
}

+static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_pipe_upcall(cd, h, svc_export_request);
+}
+
static struct svc_export *svc_export_update(struct svc_export *new,
struct svc_export *old);
static struct svc_export *svc_export_lookup(struct svc_export *);
@@ -724,7 +734,7 @@ struct cache_detail svc_export_cache = {
.hash_table = export_table,
.name = "nfsd.export",
.cache_put = svc_export_put,
- .cache_request = svc_export_request,
+ .cache_upcall = svc_export_upcall,
.cache_parse = svc_export_parse,
.cache_show = svc_export_show,
.match = svc_export_match,
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index e9012ad..cdfa86f 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -146,6 +146,12 @@ idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
}

static int
+idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
+{
+ return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
+}
+
+static int
idtoname_match(struct cache_head *ca, struct cache_head *cb)
{
struct ent *a = container_of(ca, struct ent, h);
@@ -192,7 +198,7 @@ static struct cache_detail idtoname_cache = {
.hash_table = idtoname_table,
.name = "nfs4.idtoname",
.cache_put = ent_put,
- .cache_request = idtoname_request,
+ .cache_upcall = idtoname_upcall,
.cache_parse = idtoname_parse,
.cache_show = idtoname_show,
.warn_no_listener = warn_no_idmapd,
@@ -325,6 +331,12 @@ nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
}

static int
+nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
+{
+ return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
+}
+
+static int
nametoid_match(struct cache_head *ca, struct cache_head *cb)
{
struct ent *a = container_of(ca, struct ent, h);
@@ -363,7 +375,7 @@ static struct cache_detail nametoid_cache = {
.hash_table = nametoid_table,
.name = "nfs4.nametoid",
.cache_put = ent_put,
- .cache_request = nametoid_request,
+ .cache_upcall = nametoid_upcall,
.cache_parse = nametoid_parse,
.cache_show = nametoid_show,
.warn_no_listener = warn_no_idmapd,
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 3d1fad2..23ee259 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -70,9 +70,9 @@ struct cache_detail {
char *name;
void (*cache_put)(struct kref *);

- void (*cache_request)(struct cache_detail *cd,
- struct cache_head *h,
- char **bpp, int *blen);
+ int (*cache_upcall)(struct cache_detail *,
+ struct cache_head *);
+
int (*cache_parse)(struct cache_detail *,
char *buf, int len);

@@ -135,6 +135,13 @@ extern struct cache_head *
sunrpc_cache_update(struct cache_detail *detail,
struct cache_head *new, struct cache_head *old, int hash);

+extern int
+sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
+ void (*cache_request)(struct cache_detail *,
+ struct cache_head *,
+ char **,
+ int *));
+

extern void cache_clean_deferred(void *owner);

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 2278a50..2e6a148 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -181,6 +181,11 @@ static void rsi_request(struct cache_detail *cd,
(*bpp)[-1] = '\n';
}

+static int rsi_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_pipe_upcall(cd, h, rsi_request);
+}
+

static int rsi_parse(struct cache_detail *cd,
char *mesg, int mlen)
@@ -270,7 +275,7 @@ static struct cache_detail rsi_cache = {
.hash_table = rsi_table,
.name = "auth.rpcsec.init",
.cache_put = rsi_put,
- .cache_request = rsi_request,
+ .cache_upcall = rsi_upcall,
.cache_parse = rsi_parse,
.match = rsi_match,
.init = rsi_init,
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index c8e7d2d..e438352 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
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 5c865e2..6caffa3 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -171,6 +171,11 @@ static void ip_map_request(struct cache_detail *cd,
(*bpp)[-1] = '\n';
}

+static int ip_map_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_pipe_upcall(cd, h, ip_map_request);
+}
+
static struct ip_map *ip_map_lookup(char *class, struct in6_addr *addr);
static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);

@@ -289,7 +294,7 @@ struct cache_detail ip_map_cache = {
.hash_table = ip_table,
.name = "auth.unix.ip",
.cache_put = ip_map_put,
- .cache_request = ip_map_request,
+ .cache_upcall = ip_map_upcall,
.cache_parse = ip_map_parse,
.cache_show = ip_map_show,
.match = ip_map_match,
@@ -523,6 +528,11 @@ static void unix_gid_request(struct cache_detail *cd,
(*bpp)[-1] = '\n';
}

+static int unix_gid_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_pipe_upcall(cd, h, unix_gid_request);
+}
+
static struct unix_gid *unix_gid_lookup(uid_t uid);
extern struct cache_detail unix_gid_cache;

@@ -622,7 +632,7 @@ struct cache_detail unix_gid_cache = {
.hash_table = gid_table,
.name = "auth.unix.gid",
.cache_put = unix_gid_put,
- .cache_request = unix_gid_request,
+ .cache_upcall = unix_gid_upcall,
.cache_parse = unix_gid_parse,
.cache_show = unix_gid_show,
.match = unix_gid_match,
--
1.6.0.4