gfapi: Fix the crashes caused by global_xlator and THIS

Issue: http://thread.gmane.org/gmane.comp.file-systems.gluster.devel/10922

The right fix for this is elaborate and intrusive, until it is in place,
this patch provides a temperory fix. This fix is necessary, as without this
libgfapi applications like qemu, samba, NFS ganesha are prone to crashes.
This patch will be reverted completely, once the actual fix gets accepted.

Change-Id: Ic975ab0bb03ba415cdf9bddba1534ba4d2d2820c
BUG: 1319374
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/13784
Smoke: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 53 insertions, 7 deletions

diff --git a/api/src/glfs.c b/api/src/glfs.c
index 037b579225f..6c152ae56ed 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -651,6 +651,49 @@ err:
         return NULL;
 }
 
+extern xlator_t global_xlator;
+extern glusterfs_ctx_t *global_ctx;
+extern pthread_mutex_t global_ctx_mutex;
+
+static int
+glfs_init_global_ctx ()
+{
+        int              ret = 0;
+        glusterfs_ctx_t *ctx = NULL;
+
+        pthread_mutex_lock (&global_ctx_mutex);
+        {
+                if (global_xlator.ctx)
+                        goto unlock;
+
+                ctx = glusterfs_ctx_new ();
+                if (!ctx) {
+                        ret = -1;
+                        goto unlock;
+                }
+
+                gf_log_globals_init (ctx, GF_LOG_NONE);
+
+                global_ctx = ctx;
+                global_xlator.ctx = global_ctx;
+
+                ret = glusterfs_ctx_defaults_init (ctx);
+                if (ret) {
+                        global_ctx = NULL;
+                        global_xlator.ctx = NULL;
+                        goto unlock;
+                }
+        }
+unlock:
+        pthread_mutex_unlock (&global_ctx_mutex);
+
+        if (ret)
+                FREE (ctx);
+
+        return ret;
+}
+
+
 struct glfs *
 pub_glfs_new (const char *volname)
 {
@@ -679,11 +722,9 @@ pub_glfs_new (const char *volname)
                 goto fini;
 
         old_THIS = THIS;
-        /* THIS is set to NULL so that we do not modify the caller xlators'
-         * ctx, instead we set the global_xlator->ctx
-         */
-        THIS = NULL;
-        THIS->ctx = ctx;
+        ret = glfs_init_global_ctx ();
+        if (ret)
+                goto fini;
 
         /* then ctx_defaults_init, for xlator_mem_acct_init(THIS) */
 
@@ -795,12 +836,16 @@ GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_set_volfile, 3.4.0);
 int
 pub_glfs_set_logging (struct glfs *fs, const char *logfile, int loglevel)
 {
-        int  ret = -1;
-        char *tmplog = NULL;
+        int              ret     = -1;
+        char            *tmplog  = NULL;
+        glusterfs_ctx_t *old_ctx = NULL;
 
         DECLARE_OLD_THIS;
         __GLFS_ENTRY_VALIDATE_FS (fs, invalid_fs);
 
+        old_ctx = THIS->ctx;
+        THIS->ctx = fs->ctx;
+
         if (!logfile) {
                 ret = gf_set_log_file_path (&fs->ctx->cmd_args);
                 if (ret)
@@ -823,6 +868,7 @@ pub_glfs_set_logging (struct glfs *fs, const char *logfile, int loglevel)
                 goto out;
 
 out:
+        THIS->ctx = old_ctx;
         __GLFS_EXIT_FS;
 
 invalid_fs: