diff options
| -rw-r--r-- | support/nfs/svc_socket.c | 21 | ||||
| -rw-r--r-- | utils/mountd/mountd.c | 123 | ||||
| -rw-r--r-- | utils/mountd/mountd.man | 7 |
3 files changed, 142 insertions, 9 deletions
diff --git a/support/nfs/svc_socket.c b/support/nfs/svc_socket.c index a3cb7ce..888c915 100644 --- a/support/nfs/svc_socket.c +++ b/support/nfs/svc_socket.c @@ -22,6 +22,7 @@ #include <netdb.h> #include <rpc/rpc.h> #include <sys/socket.h> +#include <sys/fcntl.h> #include <errno.h> #ifdef _LIBC @@ -112,6 +113,26 @@ svc_socket (u_long number, int type, int protocol, int reuse) } } + if (sock >= 0 && protocol == IPPROTO_TCP) + { + /* Make the TCP rendezvous socket non-block to avoid + * problems with blocking in accept() after a spurious + * wakeup from the kernel */ + int flags; + if ((flags = fcntl(sock, F_GETFL)) < 0) + { + perror (_("svc_socket: can't get socket flags")); + (void) __close (sock); + sock = -1; + } + else if (fcntl(sock, F_SETFL, flags|O_NONBLOCK) < 0) + { + perror (_("svc_socket: can't set socket flags")); + (void) __close (sock); + sock = -1; + } + } + return sock; } diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c index 43606dd..e402bf8 100644 --- a/utils/mountd/mountd.c +++ b/utils/mountd/mountd.c @@ -21,6 +21,7 @@ #include <errno.h> #include <fcntl.h> #include <sys/resource.h> +#include <sys/wait.h> #include "xmalloc.h" #include "misc.h" #include "mountd.h" @@ -43,6 +44,13 @@ int new_cache = 0; * send mount or unmount requests -- the callout is not needed for 2.6 kernel */ char *ha_callout_prog = NULL; +/* Number of mountd threads to start. Default is 1 and + * that's probably enough unless you need hundreds of + * clients to be able to mount at once. */ +static int num_threads = 1; +/* Arbitrary limit on number of threads */ +#define MAX_THREADS 64 + static struct option longopts[] = { { "foreground", 0, 0, 'F' }, @@ -57,24 +65,106 @@ static struct option longopts[] = { "no-tcp", 0, 0, 'n' }, { "ha-callout", 1, 0, 'H' }, { "state-directory-path", 1, 0, 's' }, + { "num-threads", 1, 0, 't' }, { NULL, 0, 0, 0 } }; static int nfs_version = -1; +static void +unregister_services (void) +{ + if (nfs_version & 0x1) + pmap_unset (MOUNTPROG, MOUNTVERS); + if (nfs_version & (0x1 << 1)) + pmap_unset (MOUNTPROG, MOUNTVERS_POSIX); + if (nfs_version & (0x1 << 2)) + pmap_unset (MOUNTPROG, MOUNTVERS_NFSV3); +} + +/* Wait for all worker child processes to exit and reap them */ +static void +wait_for_workers (void) +{ + int status; + pid_t pid; + + for (;;) { + + pid = waitpid(0, &status, 0); + + if (pid < 0) { + if (errno == ECHILD) + return; /* no more children */ + xlog(L_FATAL, "mountd: can't wait: %s\n", + strerror(errno)); + } + + /* Note: because we SIG_IGN'd SIGCHLD earlier, this + * does not happen on 2.6 kernels, and waitpid() blocks + * until all the children are dead then returns with + * -ECHILD. But, we don't need to do anything on the + * death of individual workers, so we don't care. */ + xlog(L_NOTICE, "mountd: reaped child %d, status %d\n", + (int)pid, status); + } +} + +/* Fork num_threads worker children and wait for them */ +static void +fork_workers(void) +{ + int i; + pid_t pid; + + xlog(L_NOTICE, "mountd: starting %d threads\n", num_threads); + + for (i = 0 ; i < num_threads ; i++) { + pid = fork(); + if (pid < 0) { + xlog(L_FATAL, "mountd: cannot fork: %s\n", + strerror(errno)); + } + if (pid == 0) { + /* worker child */ + + /* Re-enable the default action on SIGTERM et al + * so that workers die naturally when sent them. + * Only the parent unregisters with pmap and + * hence needs to do special SIGTERM handling. */ + struct sigaction sa; + sa.sa_handler = SIG_DFL; + sa.sa_flags = 0; + sigemptyset(&sa.sa_mask); + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + + /* fall into my_svc_run in caller */ + return; + } + } + + /* in parent */ + wait_for_workers(); + unregister_services(); + xlog(L_NOTICE, "mountd: no more workers, exiting\n"); + exit(0); +} + /* * Signal handler. */ static void killer (int sig) { - if (nfs_version & 0x1) - pmap_unset (MOUNTPROG, MOUNTVERS); - if (nfs_version & (0x1 << 1)) - pmap_unset (MOUNTPROG, MOUNTVERS_POSIX); - if (nfs_version & (0x1 << 2)) - pmap_unset (MOUNTPROG, MOUNTVERS_NFSV3); - xlog (L_FATAL, "Caught signal %d, un-registering and exiting.", sig); + unregister_services(); + if (num_threads > 1) { + /* play Kronos and eat our children */ + kill(0, SIGTERM); + wait_for_workers(); + } + xlog (L_FATAL, "Caught signal %d, un-registering and exiting.", sig); } static void @@ -468,7 +558,7 @@ main(int argc, char **argv) /* Parse the command line options and arguments. */ opterr = 0; - while ((c = getopt_long(argc, argv, "o:n:Fd:f:p:P:hH:N:V:vs:", longopts, NULL)) != EOF) + while ((c = getopt_long(argc, argv, "o:n:Fd:f:p:P:hH:N:V:vs:t:", longopts, NULL)) != EOF) switch (c) { case 'o': descriptors = atoi(optarg); @@ -515,6 +605,9 @@ main(int argc, char **argv) exit(1); } break; + case 't': + num_threads = atoi (optarg); + break; case 'V': nfs_version |= 1 << (atoi (optarg) - 1); break; @@ -615,6 +708,17 @@ main(int argc, char **argv) setsid(); } + /* silently bounds check num_threads */ + if (foreground) + num_threads = 1; + else if (num_threads < 1) + num_threads = 1; + else if (num_threads > MAX_THREADS) + num_threads = MAX_THREADS; + + if (num_threads > 1) + fork_workers(); + my_svc_run(); xlog(L_ERROR, "Ack! Gack! svc_run returned!\n"); @@ -629,6 +733,7 @@ usage(const char *prog, int n) " [-o num|--descriptors num] [-f exports-file|--exports-file=file]\n" " [-p|--port port] [-V version|--nfs-version version]\n" " [-N version|--no-nfs-version version] [-n|--no-tcp]\n" -" [-H ha-callout-prog] [-s|--state-directory-path path]\n", prog); +" [-H ha-callout-prog] [-s|--state-directory-path path]\n" +" [-t num|--num-threads=num]\n", prog); exit(n); } diff --git a/utils/mountd/mountd.man b/utils/mountd/mountd.man index bac4421..70166c1 100644 --- a/utils/mountd/mountd.man +++ b/utils/mountd/mountd.man @@ -125,6 +125,13 @@ If this option is not specified the default of .BR /var/lib/nfs is used. .TP +.BR "\-t N" " or " "\-\-num\-threads=N" +This option specifies the number of worker threads that rpc.mountd +spawns. The default is 1 thread, which is probably enough. More +threads are usually only needed for NFS servers which need to handle +mount storms of hundreds of NFS mounts in a few seconds, or when +your DNS server is slow or unreliable. +.TP .B \-V " or " \-\-nfs-version This option can be used to request that .B rpc.mountd |