cluster/dht: Pass the req dict instead of NULL in dht_attr2()

This bug was causing VMs to pause during rebalance. When qemu winds
down a STAT, shard fills the trusted.glusterfs.shard.file-size attribute
in the req dict which DHT doesn't wind its STAT fop with upon detecting
the file has undergone migration. As a result shard doesn't find the
value to this key in the unwind path, causing it to fail the STAT
with EINVAL.

Also, the same bug exists in other fops too, which is also fixed in
this patch.

Change-Id: Id7823fd932b4e5a9b8779ebb2b612a399c0ef5f0
BUG: 1440051
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: https://review.gluster.org/17085
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

1 files changed, 20 insertions, 33 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index e3af5a7fe8b..836a009c362 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -3834,6 +3834,7 @@ dht_fsetxattr (call_frame_t *frame, xlator_t *this,
                 goto err;
         }
 
+        local->xattr_req = xdata ? dict_ref (xdata) : dict_new ();
         local->call_cnt = call_cnt = layout->cnt;
 
         if (IA_ISDIR (fd->inode->ia_type)) {
@@ -3842,7 +3843,7 @@ dht_fsetxattr (call_frame_t *frame, xlator_t *this,
                                            layout->list[i].xlator,
                                            layout->list[i].xlator,
                                            layout->list[i].xlator->fops->fsetxattr,
-                                           fd, xattr, flags, NULL);
+                                           fd, xattr, flags, xdata);
                 }
 
         } else {
@@ -3851,9 +3852,7 @@ dht_fsetxattr (call_frame_t *frame, xlator_t *this,
                 local->rebalance.xattr = dict_ref (xattr);
                 local->rebalance.flags = flags;
 
-                xdata = xdata ? dict_ref (xdata) : dict_new ();
-                if (xdata)
-                        ret = dict_set_int8 (xdata, DHT_IATT_IN_XDATA_KEY, 1);
+                ret = dict_set_int8 (local->xattr_req, DHT_IATT_IN_XDATA_KEY, 1);
                 if (ret) {
                         gf_msg_debug (this->name, 0,
                                       "Failed to set dictionary key %s for fd=%p",
@@ -3862,11 +3861,7 @@ dht_fsetxattr (call_frame_t *frame, xlator_t *this,
 
                 STACK_WIND_COOKIE (frame, dht_file_setxattr_cbk, subvol,
                                    subvol, subvol->fops->fsetxattr, fd, xattr,
-                                   flags, xdata);
-
-                if (xdata)
-                        dict_unref (xdata);
-
+                                   flags, local->xattr_req);
         }
         return 0;
 
@@ -3962,12 +3957,12 @@ dht_setxattr2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
                 STACK_WIND_COOKIE (frame, dht_file_setxattr_cbk, subvol,
                                    subvol, subvol->fops->setxattr, &local->loc,
                                    local->rebalance.xattr,
-                                   local->rebalance.flags, NULL);
+                                   local->rebalance.flags, local->xattr_req);
         } else {
                 STACK_WIND_COOKIE (frame, dht_file_setxattr_cbk, subvol,
                                    subvol, subvol->fops->fsetxattr, local->fd,
                                    local->rebalance.xattr,
-                                   local->rebalance.flags, NULL);
+                                   local->rebalance.flags, local->xattr_req);
         }
 
         return 0;
@@ -4251,6 +4246,7 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
         if (tmp) {
                 return dht_nuke_dir (frame, this, loc, tmp);
         }
+        local->xattr_req = xdata ? dict_ref (xdata) : dict_new ();
 
         if (IA_ISDIR (loc->inode->ia_type)) {
 
@@ -4268,16 +4264,11 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
                 local->rebalance.flags = flags;
                 local->call_cnt = 1;
 
-                xdata = xdata ? dict_ref (xdata) : dict_new ();
-                if (xdata)
-                        ret = dict_set_int8 (xdata, DHT_IATT_IN_XDATA_KEY, 1);
+                ret = dict_set_int8 (local->xattr_req, DHT_IATT_IN_XDATA_KEY, 1);
 
                 STACK_WIND_COOKIE (frame, dht_file_setxattr_cbk, subvol,
                                    subvol, subvol->fops->setxattr, loc, xattr,
-                                   flags, xdata);
-
-                if (xdata)
-                        dict_unref (xdata);
+                                   flags, local->xattr_req);
         }
 
         return 0;
@@ -4396,11 +4387,11 @@ dht_removexattr2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame,
         if (local->fop == GF_FOP_REMOVEXATTR) {
                 STACK_WIND_COOKIE (frame, dht_file_removexattr_cbk, subvol,
                                    subvol, subvol->fops->removexattr,
-                                   &local->loc, local->key, NULL);
+                                   &local->loc, local->key, local->xattr_req);
         } else {
                 STACK_WIND_COOKIE (frame, dht_file_removexattr_cbk, subvol,
                                    subvol, subvol->fops->fremovexattr,
-                                   local->fd, local->key, NULL);
+                                   local->fd, local->key, local->xattr_req);
         }
 
         return 0;
@@ -4437,8 +4428,6 @@ dht_removexattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 unlock:
         UNLOCK (&frame->lock);
 
-
-
         this_call_cnt = dht_frame_return (frame);
         if (is_last_call (this_call_cnt)) {
                 DHT_STACK_UNWIND (removexattr, frame, local->op_ret,
@@ -4494,6 +4483,7 @@ dht_removexattr (call_frame_t *frame, xlator_t *this,
                 op_errno = EINVAL;
                 goto err;
         }
+        local->xattr_req = (xdata) ? dict_ref (xdata) : dict_new ();
 
         local->call_cnt = call_cnt = layout->cnt;
         local->key = gf_strdup (key);
@@ -4504,15 +4494,13 @@ dht_removexattr (call_frame_t *frame, xlator_t *this,
                                            layout->list[i].xlator,
                                            layout->list[i].xlator,
                                            layout->list[i].xlator->fops->removexattr,
-                                           loc, key, NULL);
+                                           loc, key, local->xattr_req);
                 }
 
         } else {
 
                 local->call_cnt = 1;
-                xdata = xdata ? dict_ref (xdata) : dict_new ();
-                if (xdata)
-                        ret = dict_set_int8 (xdata, DHT_IATT_IN_XDATA_KEY, 1);
+                ret = dict_set_int8 (local->xattr_req, DHT_IATT_IN_XDATA_KEY, 1);
                 if (ret) {
                         gf_msg (this->name, GF_LOG_ERROR, ENOMEM,
                                 DHT_MSG_DICT_SET_FAILED, "Failed to "
@@ -4522,10 +4510,7 @@ dht_removexattr (call_frame_t *frame, xlator_t *this,
 
                 STACK_WIND_COOKIE (frame, dht_file_removexattr_cbk, subvol,
                                    subvol, subvol->fops->removexattr, loc, key,
-                                   xdata);
-
-                if (xdata)
-                        dict_unref (xdata);
+                                   local->xattr_req);
         }
 
         return 0;
@@ -6561,7 +6546,7 @@ dht_link2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
         local->call_cnt = 2;
 
         STACK_WIND (frame, dht_link_cbk, subvol, subvol->fops->link,
-                    &local->loc, &local->loc2, NULL);
+                    &local->loc, &local->loc2, local->xattr_req);
 
         return 0;
 err:
@@ -6588,7 +6573,7 @@ dht_link_linkfile_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         srcvol = local->linkfile.srcvol;
 
         STACK_WIND (frame, dht_link_cbk, srcvol, srcvol->fops->link,
-                    &local->loc, &local->loc2, xdata);
+                    &local->loc, &local->loc2, local->xattr_req);
 
         return 0;
 
@@ -6597,7 +6582,7 @@ err:
         dht_set_fixed_dir_stat (preparent);
         dht_set_fixed_dir_stat (postparent);
         DHT_STACK_UNWIND (link, frame, op_ret, op_errno, inode, stbuf, preparent,
-                          postparent, NULL);
+                          postparent, xdata);
 
         return 0;
 }
@@ -6648,6 +6633,8 @@ dht_link (call_frame_t *frame, xlator_t *this,
                 op_errno = ENOMEM;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         if (hashed_subvol != cached_subvol) {
                 gf_uuid_copy (local->gfid, oldloc->inode->gfid);