[Fix] Fix another locking issue with mapped files

diff --git a/src/libstat/backends/mmaped_file.c b/src/libstat/backends/mmaped_file.c
index 6ebe904e4280fcc9ccf07a921959af1841f843af..582818f27e9506aaa493c9d521deac101b6bda5e 100644 (file)
--- a/src/libstat/backends/mmaped_file.c
+++ b/src/libstat/backends/mmaped_file.c
@@ -417,7 +417,7 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
        lock = g_strconcat (filename, ".lock", NULL);
        lock_fd = open (lock, O_WRONLY|O_CREAT|O_EXCL, 00600);
 
-       if (lock_fd == -1) {
+       while (lock_fd == -1) {
                /* Wait for lock */
                lock_fd = open (lock, O_WRONLY|O_CREAT|O_EXCL, 00600);
                if (lock_fd != -1) {
@@ -432,13 +432,6 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
                }
        }
 
-       old = rspamd_mmaped_file_open (pool, filename, old_size, stcf);
-
-       if (old == NULL) {
-               msg_warn_pool ("old file %s is invalid mmapped file, just move it",
-                               filename);
-       }
-
        backup = g_strconcat (filename, ".old", NULL);
        if (rename (filename, backup) == -1) {
                msg_err_pool ("cannot rename %s to %s: %s", filename, backup, strerror (
@@ -451,13 +444,23 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
                return NULL;
        }
 
+       old = rspamd_mmaped_file_open (pool, backup, old_size, stcf);
+
+       if (old == NULL) {
+               msg_warn_pool ("old file %s is invalid mmapped file, just move it",
+                               backup);
+       }
+
+       /* We need to release our lock here */
+       unlink (lock);
+       close (lock_fd);
+       g_free (lock);
+
        /* Now create new file with required size */
        if (rspamd_mmaped_file_create (filename, size, stcf, pool) != 0) {
                msg_err_pool ("cannot create new file");
+               rspamd_mmaped_file_close (old);
                g_free (backup);
-               unlink (lock);
-               g_free (lock);
-               close (lock_fd);
 
                return NULL;
        }
@@ -473,9 +476,7 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
                        }
 
                        msg_err_pool ("cannot open file: %s", strerror (errno));
-                       unlink (lock);
-                       g_free (lock);
-                       close (lock_fd);
+                       rspamd_mmaped_file_close (old);
                        g_free (backup);
                        return NULL;
                }
@@ -487,9 +488,7 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
                                mmap (NULL, old_size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
                        msg_err_pool ("cannot mmap file: %s", strerror (errno));
                        close (fd);
-                       unlink (lock);
-                       g_free (lock);
-                       close (lock_fd);
+                       rspamd_mmaped_file_close (old);
                        g_free (backup);
                        return NULL;
                }
@@ -517,14 +516,11 @@ rspamd_mmaped_file_reindex (rspamd_mempool_t *pool,
 
                munmap (map, old_size);
                close (fd);
-               unlink (backup);
                rspamd_mmaped_file_close_file (pool, old);
        }
 
+       unlink (backup);
        g_free (backup);
-       unlink (lock);
-       g_free (lock);
-       close (lock_fd);
 
        return new;
 
@@ -568,7 +564,25 @@ rspamd_mmaped_file_open (rspamd_mempool_t *pool,
 {
        struct stat st;
        rspamd_mmaped_file_t *new_file;
+       struct timespec sleep_ts = {
+                       .tv_sec = 0,
+                       .tv_nsec = 1000000
+       };
+       gchar *lock;
+       gint lock_fd;
+
+       lock = g_strconcat (filename, ".lock", NULL);
+       lock_fd = open (lock, O_WRONLY|O_CREAT|O_EXCL, 00600);
 
+       if (lock_fd == -1) {
+               msg_info_pool ("cannot open file %s, it is locked by another process",
+                               filename, strerror (errno), errno);
+               return NULL;
+       }
+
+       close (lock_fd);
+       unlink (lock);
+       g_free (lock);
 
        if (stat (filename, &st) == -1) {
                msg_info_pool ("cannot stat file %s, error %s, %d", filename, strerror (
@@ -641,6 +655,8 @@ rspamd_mmaped_file_open (rspamd_mempool_t *pool,
 
        g_assert (stcf->clcf != NULL);
 
+       msg_debug_pool ("opened statfile %s of size %l", filename, (long)size);
+
        return new_file;
 }
 
@@ -684,6 +700,7 @@ rspamd_mmaped_file_create (const gchar *filename,
        gint fd, lock_fd;
        guint buflen = 0, nblocks;
        gchar *buf = NULL, *lock;
+       struct stat sb;
        gpointer tok_conf;
        gsize tok_conf_len;
        struct timespec sleep_ts = {
@@ -703,21 +720,30 @@ rspamd_mmaped_file_create (const gchar *filename,
        lock = g_strconcat (filename, ".lock", NULL);
        lock_fd = open (lock, O_WRONLY|O_CREAT|O_EXCL, 00600);
 
-       if (lock_fd == -1) {
+       while (lock_fd == -1) {
                /* Wait for lock */
                lock_fd = open (lock, O_WRONLY|O_CREAT|O_EXCL, 00600);
                if (lock_fd != -1) {
-                       unlink (lock);
-                       close (lock_fd);
-                       g_free (lock);
+                       if (stat (filename, &sb) != -1) {
+                               /* File has been created by some other process */
+                               unlink (lock);
+                               close (lock_fd);
+                               g_free (lock);
+
+                               return 0;
+                       }
 
-                       return 0;
+                       /* We still need to create it */
+                       goto create;
                }
                else {
                        nanosleep (&sleep_ts, NULL);
                }
        }
 
+create:
+
+       msg_debug_pool ("create statfile %s of size %l", filename, (long)size);
        nblocks =
                (size - sizeof (struct stat_file_header) -
                sizeof (struct stat_file_section)) / sizeof (struct stat_file_block);
@@ -831,6 +857,7 @@ rspamd_mmaped_file_create (const gchar *filename,
        unlink (lock);
        close (lock_fd);
        g_free (lock);
+       msg_debug_pool ("created statfile %s of size %l", filename, (long)size);
 
        return 0;
 }
@@ -907,9 +934,10 @@ rspamd_mmaped_file_close (gpointer p)
 {
        rspamd_mmaped_file_t *mf = p;
 
-       g_assert (p != NULL);
 
-       rspamd_mmaped_file_close_file (mf->pool, mf);
+       if (mf) {
+               rspamd_mmaped_file_close_file (mf->pool, mf);
+       }
 
 }