#define DBOPTIONS (DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN)
int nocniddb = 0; /* Dont open CNID database, only scan filesystem */
-volatile sig_atomic_t alarmed;
+volatile sig_atomic_t alarmed; /* flags for signals */
+int db_locked; /* have we got the fcntl lock on lockfile ? */
static DBD *dbd;
static int verbose; /* Logging flag */
}
}
-static int get_lock(const char *dbpath)
+
+/*!
+ * Get lock on db lock file
+ *
+ * @args cmd (r) !=0: lock, 0: unlock
+ * @args dbpath (r) path to lockfile, only used on first call,
+ * later the stored fd is used
+ * @returns 1 if lock was acquired, 0 if file is already locked, -1 on error
+ */
+int get_lock(int cmd, const char *dbpath)
{
- int lockfd;
+ static int lockfd = -1;
char lockpath[PATH_MAX];
struct flock lock;
struct stat st;
- if ( (strlen(dbpath) + strlen(LOCKFILENAME+1)) > (PATH_MAX - 1) ) {
- dbd_log( LOGSTD, ".AppleDB pathname too long");
- exit(EXIT_FAILURE);
- }
- strncpy(lockpath, dbpath, PATH_MAX - 1);
- strcat(lockpath, "/");
- strcat(lockpath, LOCKFILENAME);
+ if (cmd == 0) {
+ if (lockfd == -1)
+ return -1;
- if ((lockfd = open(lockpath, O_RDWR | O_CREAT, 0644)) < 0) {
- dbd_log( LOGSTD, "Error opening lockfile: %s", strerror(errno));
- exit(EXIT_FAILURE);
+ lock.l_start = 0;
+ lock.l_whence = SEEK_SET;
+ lock.l_len = 0;
+ lock.l_type = F_UNLCK;
+ fcntl(lockfd, F_SETLK, &lock);
+ close(lockfd);
+ lockfd = -1;
+ return 0;
}
- if ((stat(dbpath, &st)) != 0) {
- dbd_log( LOGSTD, "Error statting lockfile: %s", strerror(errno));
- exit(EXIT_FAILURE);
- }
+ if (lockfd == -1) {
+ if ( (strlen(dbpath) + strlen(LOCKFILENAME+1)) > (PATH_MAX - 1) ) {
+ dbd_log( LOGSTD, ".AppleDB pathname too long");
+ return -1;
+ }
+ strncpy(lockpath, dbpath, PATH_MAX - 1);
+ strcat(lockpath, "/");
+ strcat(lockpath, LOCKFILENAME);
- if ((chown(lockpath, st.st_uid, st.st_gid)) != 0) {
- dbd_log( LOGSTD, "Error inheriting lockfile permissions: %s", strerror(errno));
- exit(EXIT_FAILURE);
+ if ((lockfd = open(lockpath, O_RDWR | O_CREAT, 0644)) < 0) {
+ dbd_log( LOGSTD, "Error opening lockfile: %s", strerror(errno));
+ return -1;
+ }
+
+ if ((stat(dbpath, &st)) != 0) {
+ dbd_log( LOGSTD, "Error statting lockfile: %s", strerror(errno));
+ return -1;
+ }
+
+ if ((chown(lockpath, st.st_uid, st.st_gid)) != 0) {
+ dbd_log( LOGSTD, "Error inheriting lockfile permissions: %s", strerror(errno));
+ return -1;
+ }
}
lock.l_start = 0;
if (fcntl(lockfd, F_SETLK, &lock) < 0) {
if (errno == EACCES || errno == EAGAIN) {
if (exclusive) {
- dbd_log( LOGSTD, "Database is in use and exlusive was requested", strerror(errno));
- exit(EXIT_FAILURE);
+ dbd_log(LOGSTD, "Database is in use and exlusive was requested");
+ return -1;
};
+ dbd_log(LOGDEBUG, "get_lock: couldn't lock");
+ return 0;
} else {
dbd_log( LOGSTD, "Error getting fcntl F_WRLCK on lockfile: %s", strerror(errno));
- exit(EXIT_FAILURE);
+ return -1;
}
}
-
- return lockfd;
-}
-static void free_lock(int lockfd)
-{
- struct flock lock;
-
- lock.l_start = 0;
- lock.l_whence = SEEK_SET;
- lock.l_len = 0;
- lock.l_type = F_UNLCK;
- fcntl(lockfd, F_SETLK, &lock);
- close(lockfd);
+ dbd_log(LOGDEBUG, "get_lock: got lock");
+ return 1;
}
static void usage (void)
close(dbdirfd);
}
- /*
- Before we do anything else, check if there is an instance of cnid_dbd
- running already and silently exit if yes.
- */
- lockfd = get_lock(dbpath);
+ /* Get db lock, which exits if exclusive was requested and it already is locked */
+ if ((db_locked = get_lock(1, dbpath)) == -1)
+ goto exit_failure;
/* Prepare upgrade ? */
if (prep_upgrade) {
/* Check if -f is requested and wipe db if yes */
if ((flags & DBD_FLAGS_FORCE) && rebuild && (volinfo.v_flags & AFPVOL_CACHE)) {
char cmd[8 + MAXPATHLEN];
- close(lockfd);
+ if ((db_locked = get_lock(0, NULL)) != 0)
+ goto exit_failure;
snprintf(cmd, 8 + MAXPATHLEN, "rm -f %s/*", dbpath);
dbd_log( LOGDEBUG, "Removing old database of volume: '%s'", volpath);
system(cmd);
dbd_log( LOGDEBUG, "Removed old database.");
- lockfd = get_lock(dbpath);
+ if ((db_locked = get_lock(1, dbpath)) == -1)
+ goto exit_failure;
}
/*
if ((dbd = dbif_init(dbpath, "cnid2.db")) == NULL)
goto exit_failure;
- if (dbif_env_open(dbd, &db_param, exclusive ? (DBOPTIONS | DB_RECOVER) : DBOPTIONS) < 0) {
+ if (dbif_env_open(dbd,
+ &db_param,
+ exclusive ? (DBOPTIONS | DB_RECOVER) : DBOPTIONS) < 0) {
dbd_log( LOGSTD, "error opening database!");
goto exit_failure;
}
ret = 0;
exit_failure:
- free_lock(lockfd);
+ get_lock(0, NULL);
if ((fchdir(cdir)) < 0)
dbd_log(LOGSTD, "fchdir: %s", strerror(errno));
(strcmp(a,c) b 0)
extern int nocniddb; /* Dont open CNID database, only scan filesystem */
+extern int db_locked; /* have we got the fcntl lock on lockfd ? */
extern volatile sig_atomic_t alarmed;
extern struct volinfo *volinfo;
extern char cwdbuf[MAXPATHLEN+1];
extern void dbd_log(enum logtype lt, char *fmt, ...);
extern int cmd_dbd_scanvol(DBD *dbd, struct volinfo *volinfo, dbd_flags_t flags);
+extern int get_lock(int cmd, const char *dbpath);
/*
Functions for querying the database which couldn't be reused from the existing
struct dirent *ep;
static struct stat st; /* Save some stack space */
+ /* keep trying to get the lock */
+ if (!db_locked)
+ if ((db_locked = get_lock(1, NULL)) == -1)
+ return -1;
+
/* Check again for .AppleDouble folder, check_adfile also checks/creates it */
if ((addir_ok = check_addir(volroot)) != 0)
if ( ! (dbd_flags & DBD_FLAGS_SCAN))
Note: DB_INIT_LOCK is here so we can run the db_* utilities while netatalk is running.
It's a likey performance hit, but it might we worth it.
*/
-#define DBOPTIONS (DB_CREATE | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_LOCK | DB_INIT_TXN | DB_RECOVER)
+#define DBOPTIONS (DB_CREATE | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_LOCK | DB_INIT_TXN)
static DBD *dbd;
-
static int exit_sig = 0;
+static int db_locked;
static void sig_exit(int signo)
{
return;
}
+/*!
+ * Get lock on db lock file
+ *
+ * @args cmd (r) !=0: lock, 0: unlock
+ * @returns 1 if lock was acquired, 0 if file is already locked, -1 on error
+ */
+static int get_lock(int cmd)
+{
+ static int lockfd = -1;
+ struct flock lock;
+
+ if (cmd == 0) {
+ if (lockfd == -1)
+ return -1;
+
+ lock.l_start = 0;
+ lock.l_whence = SEEK_SET;
+ lock.l_len = 0;
+ lock.l_type = F_UNLCK;
+ fcntl(lockfd, F_SETLK, &lock);
+ close(lockfd);
+ lockfd = -1;
+ return 0;
+ }
+
+ if (lockfd == -1) {
+ if ((lockfd = open(LOCKFILENAME, O_RDWR | O_CREAT, 0644)) < 0) {
+ LOG(log_error, logtype_cnid, "get_lock: error opening lockfile: %s", strerror(errno));
+ return -1;
+ }
+ }
+
+ lock.l_start = 0;
+ lock.l_whence = SEEK_SET;
+ lock.l_len = 0;
+ lock.l_type = F_WRLCK;
+
+ if (fcntl(lockfd, F_SETLK, &lock) < 0) {
+ if (errno == EACCES || errno == EAGAIN) {
+ LOG(log_debug, logtype_cnid, "get_lock: couldn't lock");
+ return 0;
+ } else {
+ LOG(log_error, logtype_cnid, "get_lock: fcntl F_WRLCK lockfile: %s", strerror(errno));
+ return -1;
+ }
+ }
+
+ LOG(log_debug, logtype_cnid, "get_lock: got lock");
+ return 1;
+}
+
/*
The dbd_XXX and comm_XXX functions all obey the same protocol for return values:
dbp->flush_interval, timebuf);
while (1) {
+ /*
+ * If we haven't got the lock yet, get it now.
+ * Prevents a race with dbd:
+ * 1. no cnid_dbd running
+ * 2. dbd -r starts, gets the lock
+ * 3. cnid_dbd starts, doesn't get lock, doesn't run recovery, all is fine
+ * 4. dbd from (2) finishes, drops lock
+ * 5. anothet dbd but this time with -re is started which
+ * - succeeds getting the lock
+ * - runs recovery => this kills (3)
+ */
+ if (!db_locked)
+ if ((db_locked = get_lock(1)) == -1)
+ return -1;
timeout = min(time_next_flush, time_last_rqst +dbp->idle_timeout);
if (timeout > now)
timeout -= now;
}
}
-/* ------------------------ */
-static int get_lock(void)
-{
- int lockfd;
- struct flock lock;
-
- if ((lockfd = open(LOCKFILENAME, O_RDWR | O_CREAT, 0644)) < 0) {
- LOG(log_error, logtype_cnid, "main: error opening lockfile: %s", strerror(errno));
- exit(1);
- }
-
- lock.l_start = 0;
- lock.l_whence = SEEK_SET;
- lock.l_len = 0;
- lock.l_type = F_WRLCK;
-
- if (fcntl(lockfd, F_SETLK, &lock) < 0) {
- if (errno == EACCES || errno == EAGAIN) {
- exit(0);
- } else {
- LOG(log_error, logtype_cnid, "main: fcntl F_WRLCK lockfile: %s", strerror(errno));
- exit(1);
- }
- }
-
- return lockfd;
-}
/* ----------------------- */
static void set_signal(void)
}
}
-/* ----------------------- */
-static void free_lock(int lockfd)
-{
- struct flock lock;
-
- lock.l_start = 0;
- lock.l_whence = SEEK_SET;
- lock.l_len = 0;
- lock.l_type = F_UNLCK;
- fcntl(lockfd, F_SETLK, &lock);
- close(lockfd);
-}
-
/* ------------------------ */
int main(int argc, char *argv[])
{
struct db_param *dbp;
int err = 0;
- int lockfd, ctrlfd, clntfd;
+ int ctrlfd, clntfd;
char *dir, *logconfig;
set_processname("cnid_dbd");
/* Before we do anything else, check if there is an instance of cnid_dbd
running already and silently exit if yes. */
- lockfd = get_lock();
+ if ((db_locked = get_lock(1)) == -1) {
+ exit(1);
+ }
LOG(log_info, logtype_cnid, "Startup, DB dir %s", dir);
if (NULL == (dbd = dbif_init(".", "cnid2.db")))
exit(2);
- if (dbif_env_open(dbd, dbp, DBOPTIONS) < 0)
+ /* Only recover if we got the lock */
+ if (dbif_env_open(dbd,
+ dbp,
+ db_locked ? DBOPTIONS | DB_RECOVER : DBOPTIONS) < 0)
exit(2); /* FIXME: same exit code as failure for dbif_open() */
LOG(log_debug, logtype_cnid, "Finished initializing BerkeleyDB environment");
if (dbif_prep_upgrade(dir) < 0)
err++;
- free_lock(lockfd);
+ (void)get_lock(0);
if (err)
exit(4);
projects / netatalk.git / commitdiff