features/gfid-access: calloc gfid and set in xdata

Backport of http://review.gluster.org/#/c/7978/

Problem: the gfid passed to ga_fill_tmp_loc() was a stack variable which
the function set in the xdata dictionary. Accessing it in a later point
in time gave unexpected values.

This was easy to hit when AFR was involved like so:
ga_mknod()--->xxx-->afr_mknod():
In afr_mknod transaction, once the stack-winds for the lock-phase are sent,
the gfid in xdata becomes out of scope. When we send the actual op i.e.
afr_mknod_wind(), the gfid in xdata is stale, causing posix to set junk
gfids on the files.

Fix:
calloc the gfid and set it in the dict.

Thanks to Pranith for the RCA!

Change-Id: Ief2080836dc2923dec4be44dda4f6211430e535e
BUG: 1104959
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/7985
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/xlators/features/gfid-access/src/gfid-access.c b/xlators/features/gfid-access/src/gfid-access.c
index 8e614397c13..2d6fbd59fab 100644
--- a/xlators/features/gfid-access/src/gfid-access.c
+++ b/xlators/features/gfid-access/src/gfid-access.c
@@ -258,6 +258,7 @@ ga_fill_tmp_loc (loc_t *loc, xlator_t *this, uuid_t gfid,
         int       ret    = -1;
         uint64_t  value  = 0;
         inode_t  *parent = NULL;
+        uuid_t *gfid_ptr = NULL;
 
         parent = loc->inode;
         ret = inode_ctx_get (loc->inode, this, &value);
@@ -278,17 +279,21 @@ ga_fill_tmp_loc (loc_t *loc, xlator_t *this, uuid_t gfid,
         loc_path (new_loc, bname);
         new_loc->name = basename (new_loc->path);
 
-        /* As GFID would not be set on the entry yet, lets not send entry
-           gfid in the request */
-        /*uuid_copy (new_loc->gfid, (const unsigned char *)gfid); */
-
-        ret = dict_set_static_bin (xdata, "gfid-req", gfid, 16);
+        gfid_ptr = GF_CALLOC (1, sizeof(uuid_t), gf_common_mt_char);
+        if (!gfid_ptr) {
+                ret = -1;
+                goto out;
+        }
+        uuid_copy (*gfid_ptr, gfid);
+        ret = dict_set_dynptr (xdata, "gfid-req", gfid_ptr, sizeof (uuid_t));
         if (ret < 0)
                 goto out;
 
         ret = 0;
 
 out:
+        if (ret && gfid_ptr)
+                GF_FREE (gfid_ptr);
         return ret;
 }