#include <atalk/logger.h>
#include <atalk/cnid_dbd_private.h>
#include <atalk/volinfo.h>
+#include <atalk/util.h>
+
#include "cmd_dbd.h"
#include "dbd.h"
#include "dbif.h"
#include "db_param.h"
-#define LOCKFILENAME "lock"
#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 */
}
}
-
-/*!
- * 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)
-{
- static int lockfd = -1;
- char lockpath[PATH_MAX];
- struct flock lock;
- struct stat st;
-
- 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 ( (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 ((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;
- 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) {
- if (exclusive) {
- 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));
- return -1;
- }
- }
-
- dbd_log(LOGDEBUG, "get_lock: got lock");
- return 1;
-}
-
static void usage (void)
{
printf("Usage: dbd [-e|-t|-v|-x] -d [-i] | -s [-c|-n]| -r [-c|-f] | -u <path to netatalk volume>\n"
close(dbdirfd);
}
- /* Get db lock, which exits if exclusive was requested and it already is locked */
- if ((db_locked = get_lock(1, dbpath)) == -1)
+ /* Get db lock */
+ if ((db_locked = get_lock(LOCK_EXCL, dbpath)) == -1)
goto exit_failure;
+ if (db_locked != LOCK_EXCL) {
+ /* Couldn't get exclusive lock, try shared lock if -e wasn't requested */
+ if (exclusive) {
+ dbd_log(LOGSTD, "Database is in use and exlusive was requested");
+ goto exit_failure;
+ }
+ if ((db_locked = get_lock(LOCK_SHRD, NULL)) != LOCK_SHRD)
+ 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];
-
- if ((db_locked = get_lock(0, NULL)) != 0)
+ if ((db_locked = get_lock(LOCK_FREE, NULL)) != 0)
goto exit_failure;
snprintf(cmd, 8 + MAXPATHLEN, "rm -rf \"%s\"", dbpath);
exit(EXIT_FAILURE);
}
dbd_log( LOGDEBUG, "Removed old database.");
- if ((db_locked = get_lock(1, dbpath)) == -1)
+ if ((db_locked = get_lock(LOCK_EXCL, dbpath)) == -1)
goto exit_failure;
}
if (dbif_env_open(dbd,
&db_param,
- exclusive ? (DBOPTIONS | DB_RECOVER) : DBOPTIONS) < 0) {
+ (db_locked == LOCK_EXCL) ? (DBOPTIONS | DB_RECOVER) : DBOPTIONS) < 0) {
dbd_log( LOGSTD, "error opening database!");
goto exit_failure;
}
- if (exclusive)
+ if (db_locked == LOCK_EXCL)
dbd_log( LOGDEBUG, "Finished recovery.");
if (dbif_open(dbd, NULL, rebuildindexes) < 0) {
}
}
+ /* Downgrade db lock if not running exclusive */
+ if (!exclusive && (db_locked == LOCK_EXCL)) {
+ if (get_lock(LOCK_UNLOCK, NULL) != 0)
+ goto exit_failure;
+ if (get_lock(LOCK_SHRD, NULL) != LOCK_SHRD)
+ goto exit_failure;
+ }
+
/* Now execute given command scan|rebuild|dump */
if (dump && ! nocniddb) {
if (dbif_dump(dbd, dumpindexes) < 0) {
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))
return ret;
}
+/*!
+ * Get lock on db lock file
+ *
+ * @args cmd (r) lock command:
+ * LOCK_FREE: close lockfd
+ * LOCK_UNLOCK: unlock lockm keep lockfd open
+ * LOCK_EXCL: F_WRLCK on lockfd
+ * LOCK_SHRD: F_RDLCK on lockfd
+ * @args dbpath (r) path to lockfile, only used on first call,
+ * later the stored fd is used
+ * @returns LOCK_FREE/LOCK_UNLOCK return 0 on success, -1 on error
+ * LOCK_EXCL/LOCK_SHRD return LOCK_EXCL or LOCK_SHRD respectively on
+ * success, 0 if the lock couldn't be acquired, -1 on other errors
+ */
+int get_lock(int cmd, const char *dbpath)
+{
+ static int lockfd = -1;
+ int ret;
+ char lockpath[PATH_MAX];
+ struct stat st;
+
+ switch (cmd) {
+ case LOCK_FREE:
+ if (lockfd == -1)
+ return -1;
+ close(lockfd);
+ lockfd = -1;
+ return 0;
+
+ case LOCK_UNLOCK:
+ if (lockfd == -1)
+ return -1;
+ return unlock(lockfd, 0, SEEK_SET, 0);
+
+ case LOCK_EXCL:
+ case LOCK_SHRD:
+ if (lockfd == -1) {
+ if ( (strlen(dbpath) + strlen(LOCKFILENAME+1)) > (PATH_MAX - 1) ) {
+ LOG(log_error, logtype_cnid, ".AppleDB pathname too long");
+ return -1;
+ }
+ strncpy(lockpath, dbpath, PATH_MAX - 1);
+ strcat(lockpath, "/");
+ strcat(lockpath, LOCKFILENAME);
+
+ if ((lockfd = open(lockpath, O_RDWR | O_CREAT, 0644)) < 0) {
+ LOG(log_error, logtype_cnid, "Error opening lockfile: %s", strerror(errno));
+ return -1;
+ }
+
+ if ((stat(dbpath, &st)) != 0) {
+ LOG(log_error, logtype_cnid, "Error statting lockfile: %s", strerror(errno));
+ return -1;
+ }
+
+ if ((chown(lockpath, st.st_uid, st.st_gid)) != 0) {
+ LOG(log_error, logtype_cnid, "Error inheriting lockfile permissions: %s",
+ strerror(errno));
+ return -1;
+ }
+ }
+
+ if (cmd == LOCK_EXCL)
+ ret = write_lock(lockfd, 0, SEEK_SET, 0);
+ else
+ ret = read_lock(lockfd, 0, SEEK_SET, 0);
+
+ if (ret != 0) {
+ if (cmd == LOCK_SHRD)
+ LOG(log_error, logtype_cnid, "Volume CNID db is locked, try again...");
+ return 0;
+ }
+
+ LOG(log_debug, logtype_cnid, "get_lock: got %s lock",
+ cmd == LOCK_EXCL ? "LOCK_EXCL" : "LOCK_SHRD");
+ return cmd;
+
+ default:
+ return -1;
+ } /* switch(cmd) */
+
+ /* deadc0de, never get here */
+ return -1;
+}
+
/* --------------- */
DBD *dbif_init(const char *envhome, const char *filename)
{
#define DBIF_IDX_DIDNAME 2
#define DBIF_IDX_NAME 3
+/* get_lock cmd and return value */
+#define LOCKFILENAME "lock"
+#define LOCK_FREE 0
+#define LOCK_UNLOCK 1
+#define LOCK_EXCL 2
+#define LOCK_SHRD 3
+
/* Structures */
typedef struct {
char *name;
} DBD;
/* Functions */
+extern int get_lock(int cmd, const char *dbpath);
+
extern DBD *dbif_init(const char *envhome, const char *dbname);
extern int dbif_env_open(DBD *dbd, struct db_param *dbp, uint32_t dbenv_oflags);
extern int dbif_open(DBD *dbd, struct db_param *dbp, int reindex);
#include "dbd.h"
#include "comm.h"
-#define LOCKFILENAME "lock"
-
/*
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.
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;
switch_to_user(dbpath);
- /* Before we do anything else, check if there is an instance of cnid_dbd
- running already and silently exit if yes. */
- if ((db_locked = get_lock(1)) == -1) {
+ /* Get db lock */
+ if ((db_locked = get_lock(LOCK_EXCL, dir)) == -1) {
+ LOG(log_error, logtype_cnid, "main: fatal db lock error");
exit(1);
}
+ if (db_locked != LOCK_EXCL) {
+ /* Couldn't get exclusive lock, try shared lock */
+ if ((db_locked = get_lock(LOCK_SHRD, NULL)) != LOCK_SHRD) {
+ LOG(log_error, logtype_cnid, "main: fatal db lock error");
+ exit(1);
+ }
+ }
set_signal();
/* Only recover if we got the lock */
if (dbif_env_open(dbd,
dbp,
- db_locked ? DBOPTIONS | DB_RECOVER : DBOPTIONS) < 0)
+ (db_locked == LOCK_EXCL) ? 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");
}
LOG(log_debug, logtype_cnid, "Finished opening BerkeleyDB databases");
+ /* Downgrade db lock */
+ if (db_locked == LOCK_EXCL) {
+ if (get_lock(LOCK_UNLOCK, NULL) != 0) {
+ dbif_close(dbd);
+ exit(2);
+ }
+ if (get_lock(LOCK_SHRD, NULL) != LOCK_SHRD) {
+ dbif_close(dbd);
+ exit(2);
+ }
+ }
+
+
if (comm_init(dbp, ctrlfd, clntfd) < 0) {
dbif_close(dbd);
exit(3);
if (dbif_env_remove(dbpath) < 0)
err++;
- (void)get_lock(0);
-
if (err)
exit(4);
else if (exit_sig)
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