gfapi: Closed the logfile fd and initialize to NULL in glfs_fini

Backport of http://review.gluster.org/6552

Currently if logfile is closed and other threads call gf_log
after glfs_fini() is executed, it may lead to memory corruption.
Adding gf_log_fini() which closes the logfile and initializes
the logfile to NULL, thus any further logging happens to stderr.
Also added gf_log_globals_fini() which should be filled in the
future to release all the logging resources.

BUG: 1030228
Change-Id: I90f7fb744b05bc6bd14c61fe143c0814896991e2
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/6552
Reviewed-on: http://review.gluster.org/6731
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

3 files changed, 38 insertions, 3 deletions

diff --git a/api/src/glfs.c b/api/src/glfs.c
index 29ed47c0c61..1bae78d2378 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -666,8 +666,8 @@ glfs_fini (struct glfs *fs)
 
         glfs_subvol_done (fs, subvol);
 
-        if (ctx->log.logfile)
-                fclose (ctx->log.logfile);
+        if (gf_log_fini(ctx) != 0)
+                ret = -1;
 
         return ret;
 }
diff --git a/libglusterfs/src/logging.c b/libglusterfs/src/logging.c
index e3a4a9fde09..0058233a7cf 100644
--- a/libglusterfs/src/logging.c
+++ b/libglusterfs/src/logging.c
@@ -108,11 +108,44 @@ gf_log_set_xl_loglevel (void *this, gf_loglevel_t level)
 }
 
 void
-gf_log_fini (void)
+gf_log_globals_fini (void)
 {
         pthread_mutex_destroy (&THIS->ctx->log.logfile_mutex);
 }
 
+/** gf_log_fini - function to perform the cleanup of the log information
+ * @data - glusterfs context
+ * @return: success: 0
+ *          failure: -1
+ */
+int
+gf_log_fini (void *data)
+{
+        glusterfs_ctx_t *ctx = data;
+        int ret = 0;
+
+        if (ctx == NULL) {
+	        ret = -1;
+                goto out;
+        }
+
+        pthread_mutex_lock (&ctx->log.logfile_mutex);
+        {
+                if (ctx->log.logfile) {
+                        if (fclose (ctx->log.logfile) != 0)
+                                ret = -1;
+                        /* Logfile needs to be set to NULL, so that any
+                           call to gf_log after calling gf_log_fini, will
+                           log the message to stderr.
+                        */
+                        ctx->log.logfile = NULL;
+                }
+        }
+        pthread_mutex_unlock (&ctx->log.logfile_mutex);
+
+ out:
+        return ret;
+}
 
 #ifdef GF_USE_SYSLOG
 /**
diff --git a/libglusterfs/src/logging.h b/libglusterfs/src/logging.h
index cc806a76712..e2b7e664d0f 100644
--- a/libglusterfs/src/logging.h
+++ b/libglusterfs/src/logging.h
@@ -153,6 +153,8 @@ int gf_cmd_log_init (const char *filename);
 
 void set_sys_log_level (gf_loglevel_t level);
 
+int gf_log_fini(void *data);
+
 #define GF_DEBUG(xl, format, args...)                           \
         gf_log ((xl)->name, GF_LOG_DEBUG, format, ##args)
 #define GF_INFO(xl, format, args...)                            \