From 1f4e616bbac160630d64f0844d0cbce5d28785ea Mon Sep 17 00:00:00 2001 From: Vsevolod Stakhov Date: Mon, 1 Aug 2016 12:03:25 +0100 Subject: [PATCH] [Fix] Fix another locking issue with mapped files --- src/libstat/backends/mmaped_file.c | 84 ++++++++++++++++++++---------- 1 file changed, 56 insertions(+), 28 deletions(-) diff --git a/src/libstat/backends/mmaped_file.c b/src/libstat/backends/mmaped_file.c index 6ebe904e4..582818f27 100644 --- 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); + } } -- 2.39.5