lock bug

[GoogleCodeExporter]

在基本快照api---hlfs_list_all_snapshots(...)中存在隐含的bug, 
具体见如下分析

int hlfs_list_all_snapshots(const char *uri, char **ss_name_array) {
          .....
    if (0 > rewrite_snapshot_file(storage, ss_hashtable)) {
        HLOG_ERROR("rewrite snapshot.txt error");
        ret = -6;
        goto out;
    }
          .....
}

int rewrite_snapshot_file(struct back_storage *storage, GHashTable 
*ss_hashtable)
{
    HLOG_DEBUG("enter func %s", __func__);
    if((0 == storage->bs_file_is_exist(storage, SNAPSHOT_FILE)) && 
            (0 > storage->bs_file_delete(storage, SNAPSHOT_FILE))) {
        HLOG_ERROR("remove snapshot.txt failed");
        return -1;
    }
    bs_file_t file = storage->bs_file_create(storage, SNAPSHOT_FILE);
    if (file == NULL) {
        HLOG_ERROR("create snapshot.txt error");
        return -2;
    }
    storage->bs_file_close(storage, file);
    GList *list = g_hash_table_get_values(ss_hashtable);
    g_list_foreach(list, dump_ss_one_by_one, storage);
    g_list_free(list);
    HLOG_DEBUG("leave func %s", __func__);
    return 0;
}

void dump_ss_one_by_one(gpointer data, gpointer storage)
{
    HLOG_DEBUG("enter func %s", __func__);
    if (NULL == data || NULL == storage) {
        HLOG_ERROR("Param error");
        return ;
    }
    struct snapshot *ss = (struct snapshot *) data;
    char *file_name = SNAPSHOT_FILE;
    if (0 > dump_snapshot((struct back_storage *)storage, file_name, ss)) {
        HLOG_ERROR("dump ss error");
        return ;
    }
    HLOG_DEBUG("leave func %s", __func__);
}

以上的hlfs_list_snapshots调用了rewrite_snapshot_file，rewrite_snapshot_fi
le调用dump_ss_one_by_one,dump_ss_one_by_one又调用了dump_snapshot， 
这就出现了问题。对文件进行io操作，应该加锁的，但是这里
没有进行加锁。 
hlfs_rm_snapshot也存在这个问题，我们必须都要上锁。

Original issue reported on code.google.com by harryxi...@gmail.com on 6 Jan 2012 at 4:09

[GoogleCodeExporter]

还有一点我想不通，咱们的api  
hlfs_list_snapshots只是list所有快照，为什么要进行rewrite操作，
这个操作的意义何在？？？ 

Original comment by harryxi...@gmail.com on 6 Jan 2012 at 4:13

[GoogleCodeExporter]

我已经进行了修复，详见 r332
http://code.google.com/p/cloudxy/source/detail?r=332 

Original comment by harryxi...@gmail.com on 6 Jan 2012 at 4:35

• Changed state: Accepted

[GoogleCodeExporter]

为什么需要加锁？ 

Original comment by kanghua...@gmail.com on 9 Feb 2013 at 6:30