* Open and lock a database file *
*************************************************/
+/* Ensure the directory for the DB is present */
+
+static inline void
+db_dir_make(BOOL panic)
+{
+(void) directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, panic);
+}
+
+
+/* Lock a file to protect the DB. Return TRUE for success */
+
+static inline BOOL
+lockfile_take(open_db * dbblock, const uschar * filename, BOOL rdonly, BOOL panic)
+{
+flock_t lock_data;
+int rc, * fdp = &dbblock->lockfd;
+
+priv_drop_temp(exim_uid, exim_gid);
+if ((*fdp = Uopen(filename, O_RDWR, EXIMDB_LOCKFILE_MODE)) < 0)
+ {
+ db_dir_make(panic);
+ *fdp = Uopen(filename, O_RDWR|O_CREAT, EXIMDB_LOCKFILE_MODE);
+ }
+priv_restore();
+
+if (*fdp < 0)
+ {
+ log_write(0, LOG_MAIN, "%s",
+ string_open_failed("database lock file %s", filename));
+ errno = 0; /* Indicates locking failure */
+ return FALSE;
+ }
+
+/* Now we must get a lock on the opened lock file; do this with a blocking
+lock that times out. */
+
+lock_data.l_type = rdonly ? F_RDLCK : F_WRLCK;
+lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
+
+DEBUG(D_hints_lookup|D_retry|D_route|D_deliver)
+ debug_printf_indent("locking %s\n", filename);
+
+sigalrm_seen = FALSE;
+ALARM(EXIMDB_LOCK_TIMEOUT);
+rc = fcntl(*fdp, F_SETLKW, &lock_data);
+ALARM_CLR(0);
+
+if (sigalrm_seen) errno = ETIMEDOUT;
+if (rc < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "Failed to get %s lock for %s: %s",
+ rdonly ? "read" : "write", filename,
+ errno == ETIMEDOUT ? "timed out" : strerror(errno));
+ (void)close(*fdp); *fdp = -1;
+ errno = 0; /* Indicates locking failure */
+ return FALSE;
+ }
+
+DEBUG(D_hints_lookup) debug_printf_indent("locked %s\n", filename);
+return TRUE;
+}
+
/* Used for accessing Exim's hints databases.
Arguments:
On success, dbblock is returned. This contains the dbm pointer and
the fd of the locked lock file.
-
-There are some calls that use O_RDWR|O_CREAT for the flags. Having discovered
-this in December 2005, I'm not sure if this is correct or not, but for the
-moment I haven't changed them.
*/
open_db *
-dbfn_open(uschar *name, int flags, open_db *dbblock, BOOL lof, BOOL panic)
+dbfn_open(const uschar * name, int flags, open_db * dbblock,
+ BOOL lof, BOOL panic)
{
int rc, save_errno;
-BOOL read_only = flags == O_RDONLY;
flock_t lock_data;
uschar dirname[PATHLEN], filename[PATHLEN];
snprintf(CS dirname, sizeof(dirname), "%s/db", spool_directory);
snprintf(CS filename, sizeof(filename), "%s/%s.lockfile", dirname, name);
-priv_drop_temp(exim_uid, exim_gid);
-if ((dbblock->lockfd = Uopen(filename, O_RDWR, EXIMDB_LOCKFILE_MODE)) < 0)
- {
- (void)directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, panic);
- dbblock->lockfd = Uopen(filename, O_RDWR|O_CREAT, EXIMDB_LOCKFILE_MODE);
- }
-priv_restore();
-
-if (dbblock->lockfd < 0)
- {
- log_write(0, LOG_MAIN, "%s",
- string_open_failed("database lock file %s", filename));
- errno = 0; /* Indicates locking failure */
- DEBUG(D_hints_lookup) acl_level--;
- return NULL;
- }
-
-/* Now we must get a lock on the opened lock file; do this with a blocking
-lock that times out. */
-
-lock_data.l_type = read_only? F_RDLCK : F_WRLCK;
-lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
-
-DEBUG(D_hints_lookup|D_retry|D_route|D_deliver)
- debug_printf_indent("locking %s\n", filename);
-
-sigalrm_seen = FALSE;
-ALARM(EXIMDB_LOCK_TIMEOUT);
-rc = fcntl(dbblock->lockfd, F_SETLKW, &lock_data);
-ALARM_CLR(0);
-
-if (sigalrm_seen) errno = ETIMEDOUT;
-if (rc < 0)
+dbblock->lockfd = -1;
+if (!exim_lockfile_needed())
+ db_dir_make(panic);
+else
{
- log_write(0, LOG_MAIN|LOG_PANIC, "Failed to get %s lock for %s: %s",
- read_only ? "read" : "write", filename,
- errno == ETIMEDOUT ? "timed out" : strerror(errno));
- (void)close(dbblock->lockfd);
- errno = 0; /* Indicates locking failure */
- DEBUG(D_hints_lookup) acl_level--;
- return NULL;
+ if (!lockfile_take(dbblock, filename, flags == O_RDONLY, panic))
+ {
+ DEBUG(D_hints_lookup) acl_level--;
+ return NULL;
+ }
}
-DEBUG(D_hints_lookup) debug_printf_indent("locked %s\n", filename);
-
/* At this point we have an opened and locked separate lock file, that is,
exclusive access to the database, so we can go ahead and open it. If we are
expected to create it, don't do so at first, again so that we can detect
it easy to pin this down, there are now debug statements on either side of the
open call. */
+flags &= O_RDONLY | O_RDWR;
snprintf(CS filename, sizeof(filename), "%s/%s", dirname, name);
priv_drop_temp(exim_uid, exim_gid);
debug_printf_indent("%s\n", CS string_open_failed("DB file %s",
filename));
(void)close(dbblock->lockfd);
+ dbblock->lockfd = -1;
errno = save_errno;
DEBUG(D_hints_lookup) acl_level--;
return NULL;
debug_printf_indent("opened hints database %s: flags=%s\n", filename,
flags == O_RDONLY ? "O_RDONLY"
: flags == O_RDWR ? "O_RDWR"
- : flags == (O_RDWR|O_CREAT) ? "O_RDWR|O_CREAT"
: "??");
/* Pass back the block containing the opened database handle and the open fd
*************************************************/
/* Closing a file automatically unlocks it, so after closing the database, just
-close the lock file.
+close the lock file if there was one.
Argument: a pointer to an open database block
Returns: nothing
void
dbfn_close(open_db *dbblock)
{
+int * fdp = &dbblock->lockfd;
+
exim_dbclose(dbblock->dbptr);
-(void)close(dbblock->lockfd);
+if (*fdp >= 0) (void)close(*fdp);
DEBUG(D_hints_lookup)
- { debug_printf_indent("closed hints database and lockfile\n"); acl_level--; }
+ {
+ debug_printf_indent("closed hints database%s\n",
+ *fdp < 0 ? "" : " and lockfile");
+ acl_level--;
+ }
+*fdp = -1;
}
git://git.exim.org / exim.git / blobdiff