diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | src/config.h | 8 | ||||
| -rw-r--r-- | src/mds-server.c | 87 |
3 files changed, 51 insertions, 46 deletions
@@ -71,7 +71,7 @@ all: bin/mds bin/mds-server bin/libmdsserver.so bin/%: obj/%.o bin/libmdsserver.so mkdir -p $(shell dirname $@) - gcc $(C_FLAGS) -o $@ -Lbin -lmdsserver obj/$*.o + gcc $(C_FLAGS) -o $@ -Lbin -lmdsserver -lrt obj/$*.o obj/%.o: src/%.c src/*.h src/libmdsserver/*.h mkdir -p $(shell dirname $@) diff --git a/src/config.h b/src/config.h index da3ff81..09c3210 100644 --- a/src/config.h +++ b/src/config.h @@ -126,6 +126,14 @@ /** + * Pattern for the names of shared object to which states are marshalled + */ +#ifndef SHM_PATH_PATTERN +#define SHM_PATH_PATTERN "/.proc-pid-%lu" +#endif + + +/** * The maximum number of command line arguments to allow */ #ifndef ARGC_LIMIT diff --git a/src/mds-server.c b/src/mds-server.c index d81dd5a..8a42961 100644 --- a/src/mds-server.c +++ b/src/mds-server.c @@ -35,6 +35,9 @@ #include <errno.h> #include <pthread.h> #include <sys/socket.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <sys/stat.h> @@ -101,8 +104,7 @@ int main(int argc_, char** argv_) { int is_respawn = -1; int socket_fd = -1; - int reexec_fd = -1; - int reexec_argi = 1; + int reexec = 0; int unparsed_args_ptr = 1; char* unparsed_args[ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT + 1]; int i; @@ -176,33 +178,14 @@ int main(int argc_, char** argv_) } socket_fd = (int)r; } - else if (strstr(arg, "--re-exec=") == arg) /* Re-exec state-marshal file descriptor. */ - { - long int r; - char* endptr; - if (reexec_fd != -1) - { - fprintf(stderr, "%s: duplicate declaration of %s.\n", *argv, "--re-exec"); - return -1; - } - arg += strlen("--re-exec="); - r = strtol(arg, &endptr, 10); - if ((*argv == '\0') || isspace(*argv) || - (endptr - arg != (ssize_t)strlen(arg)) - || (r < 0) || (r > INT_MAX)) - { - fprintf(stderr, "%s: invalid value for %s: %s.\n", *argv, "--re-exec", arg); - return 1; - } - reexec_fd = (int)r; - reexec_argi = i; - } + else if (!strcmp(arg, "--re-exec")) /* Re-exec state-marshal. */ + reexec = 1; else /* Not recognised, it is probably for another server. */ unparsed_args[unparsed_args_ptr++] = arg; } unparsed_args[unparsed_args_ptr] = NULL; - if (reexec_fd >= 0) + if (reexec) is_respawn = 1; @@ -241,7 +224,7 @@ int main(int argc_, char** argv_) /* Create list and table of clients. */ - if (reexec_fd < 0) + if (reexec == 0) { if (fd_table_create(&client_map)) { @@ -285,10 +268,24 @@ int main(int argc_, char** argv_) /* Unmarshal the state of the server. */ - if (reexec_fd >= 0) + if (reexec) { - int r = unmarshal_server(reexec_fd); - close(reexec_fd); + pid_t pid = getpid(); + int reexec_fd, r; + char shm_path[NAME_MAX + 1]; + snprintf(shm_path, sizeof(shm_path) / sizeof(char), SHM_PATH_PATTERN, (unsigned long int)pid); + reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU); + if (reexec_fd < 0) + { + perror(*argv); + r = -1; + } + else + { + r = unmarshal_server(reexec_fd); + close(reexec_fd); + shm_unlink(shm_path); + } if (r < 0) { /* TODO: close all sockets we do not know what they are. */ @@ -364,12 +361,13 @@ int main(int argc_, char** argv_) reexec: { - int pipe_rw[2]; + pid_t pid = getpid(); + int reexec_fd; + char shm_path[NAME_MAX + 1]; char readlink_buf[PATH_MAX]; ssize_t readlink_ptr; char** reexec_args; char** reexec_args_; - char reexec_arg[sizeof(int) * 8 / 3 + 14]; /* Release resources. */ pthread_mutex_destroy(&slave_mutex); @@ -382,14 +380,16 @@ int main(int argc_, char** argv_) pthread_mutex_unlock(&slave_mutex); /* Marshal the state of the server. */ - if (pipe(pipe_rw) < 0) + snprintf(shm_path, sizeof(shm_path) / sizeof(char), SHM_PATH_PATTERN, (unsigned long int)pid); + reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU); + if (reexec_fd < 0) { perror(*argv); return 1; } - if (marshal_server(pipe_rw[1]) < 0) + if (marshal_server(reexec_fd) < 0) goto reexec_fail; - close(pipe_rw[1]); + close(reexec_fd); /* Re-exec the server. */ readlink_ptr = readlink(SELF_EXE, readlink_buf, (sizeof(readlink_buf) / sizeof(char)) - 1); @@ -397,31 +397,28 @@ int main(int argc_, char** argv_) goto reexec_fail; /* ‘readlink() does not append a null byte to buf.’ */ readlink_buf[readlink_ptr] = '\0'; - snprintf(reexec_arg, sizeof(reexec_arg) / sizeof(char), - "--re-exec=%i", pipe_rw[0]); reexec_args = alloca(((size_t)argc + 2) * sizeof(char*)); reexec_args_ = reexec_args; - if (reexec_fd < 0) + if (reexec == 0) { *reexec_args_++ = *argv; - *reexec_args_ = reexec_arg; + *reexec_args_ = strdup("--re-exec"); + if (*reexec_args_) + goto reexec_fail; for (i = 1; i < argc; i++) reexec_args_[i] = argv[i]; } else /* Don't let the --re-exec:s accumulate. */ - { - *reexec_args_ = *argv; - for (i = 1; i < argc; i++) - reexec_args_[i] = argv[i]; - reexec_args_[reexec_argi] = reexec_arg; - } + *reexec_args_ = *argv; + for (i = 1; i < argc; i++) + reexec_args_[i] = argv[i]; reexec_args_[argc] = NULL; execv(readlink_buf, reexec_args); reexec_fail: perror(*argv); - close(pipe_rw[0]); - close(pipe_rw[1]); + close(reexec_fd); + shm_unlink(shm_path); /* Returning non-zero is important, otherwise the server cannot be respawn if the re-exec fails. */ return 1; |