Improve locking on opening sqlite files.

diff --git a/src/libutil/sqlite_utils.c b/src/libutil/sqlite_utils.c
index bf4e5073d3c7611062ababbc61563bc9145ec76e..8bc86d331517c5701fe61cd56f6dfb2918b73177 100644 (file)
--- a/src/libutil/sqlite_utils.c
+++ b/src/libutil/sqlite_utils.c
@@ -249,7 +249,7 @@ rspamd_sqlite3_open_or_create (const gchar *path, const
        gchar lock_path[PATH_MAX], dbdir[PATH_MAX], *pdir;
        static const char sqlite_wal[] = "PRAGMA journal_mode=\"wal\";",
                        exclusive_lock_sql[] = "PRAGMA locking_mode=\"exclusive\";";
-       gboolean create = FALSE;
+       gboolean create = FALSE, has_lock = FALSE;
 
        flags = SQLITE_OPEN_READWRITE;
 #ifdef SQLITE_OPEN_SHAREDCACHE
@@ -272,32 +272,35 @@ rspamd_sqlite3_open_or_create (const gchar *path, const
 
        rspamd_snprintf (lock_path, sizeof (lock_path), "%s.lock", path);
 
-       if (access (path, R_OK) == -1 || access (lock_path, R_OK) != -1) {
+       if (access (path, R_OK) == -1) {
                flags |= SQLITE_OPEN_CREATE;
+               create = TRUE;
+       }
 
-               rspamd_snprintf (lock_path, sizeof (lock_path), "%s.lock", path);
-               lock_fd = open (lock_path, O_WRONLY|O_CREAT|O_EXCL, 00600);
 
-               if (lock_fd == -1 && (errno == EEXIST || errno == EBUSY)) {
-                       msg_debug ("checking %s to wait for db being created", lock_path);
+       rspamd_snprintf (lock_path, sizeof (lock_path), "%s.lock", path);
+       lock_fd = open (lock_path, O_WRONLY|O_CREAT|O_EXCL, 00600);
 
-                       if (!rspamd_sqlite3_wait (lock_path)) {
-                               g_set_error (err, rspamd_sqlite3_quark (),
-                                               errno, "cannot create sqlite file %s: %s",
-                                               path, strerror (errno));
+       if (lock_fd == -1 && (errno == EEXIST || errno == EBUSY)) {
+               msg_debug ("checking %s to wait for db being initialized", lock_path);
 
-                               return NULL;
-                       }
+               if (!rspamd_sqlite3_wait (lock_path)) {
+                       g_set_error (err, rspamd_sqlite3_quark (),
+                                       errno, "cannot create sqlite file %s: %s",
+                                       path, strerror (errno));
 
-                       /* At this point we have database created */
-                       create = FALSE;
+                       return NULL;
                }
-               else {
-                       msg_debug ("locking %s to block creating", lock_path);
 
-                       g_assert (rspamd_file_lock (lock_fd, FALSE));
-                       create = TRUE;
-               }
+               /* At this point we have database created */
+               create = FALSE;
+               has_lock = FALSE;
+       }
+       else {
+               msg_debug ("locking %s to block other processes", lock_path);
+
+               g_assert (rspamd_file_lock (lock_fd, FALSE));
+               has_lock = TRUE;
        }
 
        if ((rc = sqlite3_open_v2 (path, &sqlite,
@@ -338,12 +341,8 @@ rspamd_sqlite3_open_or_create (const gchar *path, const
                        return NULL;
                }
 
-               msg_debug ("removing lock from %s", lock_path);
-
                sqlite3_close (sqlite);
-               rspamd_file_unlock (lock_fd, FALSE);
-               unlink (lock_path);
-               close (lock_fd);
+
 
                /* Reopen in normal mode */
                msg_debug ("reopening %s in normal mode", path);
@@ -360,7 +359,9 @@ rspamd_sqlite3_open_or_create (const gchar *path, const
                                        rc, "cannot open sqlite db after creation %s: %d",
                                        path, rc);
        #endif
-
+                       rspamd_file_unlock (lock_fd, FALSE);
+                       unlink (lock_path);
+                       close (lock_fd);
                        return NULL;
                }
        }
@@ -370,5 +371,12 @@ rspamd_sqlite3_open_or_create (const gchar *path, const
                                sqlite3_errmsg (sqlite));
        }
 
+       if (has_lock) {
+               msg_debug ("removing lock from %s", lock_path);
+               rspamd_file_unlock (lock_fd, FALSE);
+               unlink (lock_path);
+               close (lock_fd);
+       }
+
        return sqlite;
 }