From: NeilBrown <neil@xxxxxxxxxx>
The DEFAULT_TTL affects the rate at which authentication messages are
logged. So it is useful to make it settable.
Add "-ttl" and "-T", and add clear statement in the documentation of
both the benefits and the possible negative effects of choosing a larger
value
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
support/export/cache.c | 6 +++---
support/export/v4root.c | 3 ++-
support/include/exportfs.h | 3 ++-
support/nfs/exports.c | 4 +++-
utils/mountd/mountd.c | 18 +++++++++++++++++-
utils/mountd/mountd.man | 19 ++++++++++++++++---
6 files changed, 43 insertions(+), 10 deletions(-)
diff --git a/support/export/cache.c b/support/export/cache.c
index 50f7c7a15ceb..c0848c3e437b 100644
--- a/support/export/cache.c
+++ b/support/export/cache.c
@@ -157,7 +157,7 @@ static void auth_unix_ip(int f)
bp = buf; blen = sizeof(buf);
qword_add(&bp, &blen, "nfsd");
qword_add(&bp, &blen, ipaddr);
- qword_adduint(&bp, &blen, time(0) + DEFAULT_TTL);
+ qword_adduint(&bp, &blen, time(0) + default_ttl);
if (use_ipaddr && client) {
memmove(ipaddr + 1, ipaddr, strlen(ipaddr) + 1);
ipaddr[0] = '$';
@@ -230,7 +230,7 @@ static void auth_unix_gid(int f)
bp = buf; blen = sizeof(buf);
qword_adduint(&bp, &blen, uid);
- qword_adduint(&bp, &blen, time(0) + DEFAULT_TTL);
+ qword_adduint(&bp, &blen, time(0) + default_ttl);
if (rv >= 0) {
qword_adduint(&bp, &blen, ngroups);
for (i=0; i<ngroups; i++)
@@ -968,7 +968,7 @@ static int dump_to_cache(int f, char *buf, int blen, char *domain,
ssize_t err;
if (ttl <= 1)
- ttl = DEFAULT_TTL;
+ ttl = default_ttl;
qword_add(&bp, &blen, domain);
qword_add(&bp, &blen, path);
diff --git a/support/export/v4root.c b/support/export/v4root.c
index 6f640aa9aa3f..3654bd7c10c0 100644
--- a/support/export/v4root.c
+++ b/support/export/v4root.c
@@ -45,7 +45,7 @@ static nfs_export pseudo_root = {
.e_nsqgids = 0,
.e_fsid = 0,
.e_mountpoint = NULL,
- .e_ttl = DEFAULT_TTL,
+ .e_ttl = 0,
},
.m_exported = 0,
.m_xtabent = 1,
@@ -84,6 +84,7 @@ v4root_create(char *path, nfs_export *export)
struct exportent *curexp = &export->m_export;
dupexportent(&eep, &pseudo_root.m_export);
+ eep.e_ttl = default_ttl;
eep.e_hostname = curexp->e_hostname;
strncpy(eep.e_path, path, sizeof(eep.e_path)-1);
if (strcmp(path, "/") != 0)
diff --git a/support/include/exportfs.h b/support/include/exportfs.h
index daa7e2a06d82..81d137210862 100644
--- a/support/include/exportfs.h
+++ b/support/include/exportfs.h
@@ -105,7 +105,8 @@ typedef struct mexport {
} nfs_export;
#define HASH_TABLE_SIZE 1021
-#define DEFAULT_TTL (30 * 60)
+
+extern int default_ttl;
typedef struct _exp_hash_entry {
nfs_export * p_first;
diff --git a/support/nfs/exports.c b/support/nfs/exports.c
index 037febd08d9b..2c8f0752ad9d 100644
--- a/support/nfs/exports.c
+++ b/support/nfs/exports.c
@@ -47,6 +47,8 @@ struct flav_info flav_map[] = {
const int flav_map_size = sizeof(flav_map)/sizeof(flav_map[0]);
+int default_ttl = 30 * 60;
+
static char *efname = NULL;
static XFILE *efp = NULL;
static int first;
@@ -100,7 +102,7 @@ static void init_exportent (struct exportent *ee, int fromkernel)
ee->e_nsquids = 0;
ee->e_nsqgids = 0;
ee->e_uuid = NULL;
- ee->e_ttl = DEFAULT_TTL;
+ ee->e_ttl = default_ttl;
}
struct exportent *
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index dafcc35ca9c2..22279e9afe48 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -76,9 +76,10 @@ static struct option longopts[] =
{ "no-udp", 0, 0, 'u' },
{ "log-auth", 0, 0, 'l'},
{ "cache-use-ipaddr", 0, 0, 'i'},
+ { "ttl", 1, 0, 'T'},
{ NULL, 0, 0, 0 }
};
-static char shortopts[] = "o:nFd:p:P:hH:N:V:vurs:t:gli";
+static char shortopts[] = "o:nFd:p:P:hH:N:V:vurs:t:gliT";
#define NFSVERSBIT(vers) (0x1 << (vers - 1))
#define NFSVERSBIT_ALL (NFSVERSBIT(2) | NFSVERSBIT(3) | NFSVERSBIT(4))
@@ -672,6 +673,7 @@ inline static void
read_mountd_conf(char **argv)
{
char *s;
+ int ttl;
conf_init_file(NFS_CONFFILE);
@@ -706,6 +708,10 @@ read_mountd_conf(char **argv)
else
NFSCTL_VERUNSET(nfs_version, vers);
}
+
+ ttl = conf_get_num("mountd", "ttl", default_ttl);
+ if (ttl > 0)
+ default_ttl = ttl;
}
int
@@ -715,6 +721,7 @@ main(int argc, char **argv)
unsigned int listeners = 0;
int foreground = 0;
int c;
+ int ttl;
struct sigaction sa;
struct rlimit rlim;
@@ -809,6 +816,15 @@ main(int argc, char **argv)
case 'i':
use_ipaddr = 2;
break;
+ case 'T':
+ ttl = atoi(optarg);
+ if (ttl <= 0) {
+ fprintf(stderr, "%s: bad ttl number of seconds: %s\n",
+ argv[0], optarg);
+ usage(argv[0], 1);
+ }
+ default_ttl = ttl;
+ break;
case 0:
break;
case '?':
diff --git a/utils/mountd/mountd.man b/utils/mountd/mountd.man
index 44d237e56110..82e07cf221fa 100644
--- a/utils/mountd/mountd.man
+++ b/utils/mountd/mountd.man
@@ -99,9 +99,10 @@ Turn on debugging. Valid kinds are: all, auth, call, general and parse.
.TP
.BR \-l " or " \-\-log\-auth
Enable logging of responses to authentication and access requests from
-nfsd. Each response is then cached by the kernel for 30 minutes, and
-will be refreshed after 15 minutes if the relevant client remains
-active.
+nfsd. Each response is then cached by the kernel for 30 minutes (or as set by
+.B \-\-ttl
+below), and will be refreshed after 15 minutes (half the ttl time) if
+the relevant client remains active.
Note that
.B -l
is equivalent to
@@ -135,6 +136,17 @@ log messages produced by the
.B -l
option easier to read.
.TP
+.B \-T " or " \-\-ttl
+Provide a time-to-live (TTL) for cached information given to the kernel.
+The kernel will normally request an update if the information is needed
+after half of this time has expired. Increasing the provided number,
+which is in seconds, reduces the rate of cache update requests, and this
+is particularly noticeable when these requests are logged with
+.BR \-l .
+However increasing also means that changes to hostname to address
+mappings can take longer to be noticed.
+The default TTL is 1800 (30 minutes).
+.TP
.B \-F " or " \-\-foreground
Run in foreground (do not daemonize)
.TP
@@ -269,6 +281,7 @@ section include
.BR descriptors ,
.BR port ,
.BR threads ,
+.BR ttl ,
.BR reverse-lookup ", and"
.BR state-directory-path ,
.B ha-callout
