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

    Backport of:
    > Change-Id: Id7823fd932b4e5a9b8779ebb2b612a399c0ef5f0
    > BUG: 1440051
    > Reviewed on: https://review.gluster.org/17085
    > (cherry-picked from commit d60ca8e96bbc16b13f8f3456f30ebeb16d0d1e47)

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: 1426508
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: https://review.gluster.org/17119
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

3 files changed, 74 insertions, 57 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 6df48ed8d3b..c21880bfc90 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -3832,6 +3832,7 @@ 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)) {
@@ -3840,7 +3841,7 @@ 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 {
@@ -3849,10 +3850,8 @@ 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_dynstr_with_alloc (xdata,
-                                        DHT_IATT_IN_XDATA_KEY, "yes");
+                ret = dict_set_dynstr_with_alloc (local->xattr_req,
+                                                  DHT_IATT_IN_XDATA_KEY, "yes");
                 if (ret) {
                         gf_msg_debug (this->name, 0,
                                       "Failed to set dictionary key %s for fd=%p",
@@ -3861,11 +3860,7 @@ 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;
 
@@ -3961,12 +3956,12 @@ 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;
@@ -4250,6 +4245,7 @@ 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)) {
 
@@ -4267,17 +4263,12 @@ 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_dynstr_with_alloc (xdata,
-                                              DHT_IATT_IN_XDATA_KEY, "yes");
+                ret = dict_set_dynstr_with_alloc (local->xattr_req,
+                                                  DHT_IATT_IN_XDATA_KEY, "yes");
 
                 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);
@@ -4504,16 +4494,14 @@ 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_dynstr_with_alloc (xdata,
-                                 DHT_IATT_IN_XDATA_KEY, "yes");
+                ret = dict_set_dynstr_with_alloc (local->xattr_req,
+                                                  DHT_IATT_IN_XDATA_KEY, "yes");
                 if (ret) {
                         gf_msg (this->name, GF_LOG_ERROR, ENOMEM,
                                 DHT_MSG_DICT_SET_FAILED, "Failed to "
@@ -4523,10 +4511,7 @@ 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;
@@ -6562,7 +6547,7 @@ 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:
@@ -6589,7 +6574,7 @@ 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;
 
@@ -6598,7 +6583,7 @@ 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;
 }
@@ -6649,6 +6634,8 @@ 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);
diff --git a/xlators/cluster/dht/src/dht-inode-read.c b/xlators/cluster/dht/src/dht-inode-read.c
index 58168dec81b..c53662d6740 100644
--- a/xlators/cluster/dht/src/dht-inode-read.c
+++ b/xlators/cluster/dht/src/dht-inode-read.c
@@ -76,7 +76,7 @@ dht_open2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
         if (we_are_not_migrating (ret)) {
                 /* This DHT layer is not migrating the file */
                 DHT_STACK_UNWIND (open, frame, -1, local->op_errno,
-                                  NULL, NULL);
+                                  NULL, local->rebalance.xdata);
                 return 0;
 
         }
@@ -88,7 +88,7 @@ dht_open2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND_COOKIE (frame, dht_open_cbk, subvol, subvol,
                            subvol->fops->open, &local->loc,
-                           local->rebalance.flags, local->fd, NULL);
+                           local->rebalance.flags, local->fd, local->xattr_req);
         return 0;
 
 out:
@@ -122,6 +122,8 @@ dht_open (call_frame_t *frame, xlator_t *this,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->rebalance.flags = flags;
         local->call_cnt = 1;
@@ -239,10 +241,12 @@ dht_attr2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         if (local->fop == GF_FOP_FSTAT) {
                 STACK_WIND_COOKIE (frame, dht_file_attr_cbk, subvol, subvol,
-                                   subvol->fops->fstat, local->fd, NULL);
+                                   subvol->fops->fstat, local->fd,
+                                   local->xattr_req);
         } else {
                 STACK_WIND_COOKIE (frame, dht_file_attr_cbk, subvol, subvol,
-                                   subvol->fops->stat, &local->loc, NULL);
+                                   subvol->fops->stat, &local->loc,
+                                   local->xattr_req);
         }
 
         return 0;
@@ -325,6 +329,8 @@ dht_stat (call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata)
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         if (IA_ISREG (loc->inode->ia_type)) {
                 local->call_cnt = 1;
@@ -384,6 +390,8 @@ dht_fstat (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         if (IA_ISREG (fd->inode->ia_type)) {
                 local->call_cnt = 1;
@@ -504,7 +512,7 @@ dht_readv2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND (frame, dht_readv_cbk, subvol, subvol->fops->readv,
                     local->fd, local->rebalance.size, local->rebalance.offset,
-                    local->rebalance.flags, NULL);
+                    local->rebalance.flags, local->xattr_req);
 
         return 0;
 
@@ -539,6 +547,8 @@ dht_readv (call_frame_t *frame, xlator_t *this,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->rebalance.offset = off;
         local->rebalance.size   = size;
@@ -635,7 +645,7 @@ dht_access2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND_COOKIE (frame, dht_access_cbk, subvol, subvol,
                            subvol->fops->access, &local->loc,
-                           local->rebalance.flags, NULL);
+                           local->rebalance.flags, local->xattr_req);
 
         return 0;
 
@@ -674,6 +684,8 @@ dht_access (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t mask,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_access_cbk, subvol, subvol,
                            subvol->fops->access, loc, mask, xdata);
@@ -708,9 +720,6 @@ dht_flush_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         local->op_ret = op_ret;
         local->op_errno = op_errno;
 
-        if (xdata)
-                local->rebalance.xdata = dict_ref (xdata);
-
         /* If context is set, then send flush() it to the destination */
         dht_inode_ctx_get_mig_info (this, local->fd->inode, NULL, &subvol);
         if (subvol && dht_fd_open_on_dst (this, local->fd, subvol)) {
@@ -751,7 +760,7 @@ dht_flush2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND (frame, dht_flush_cbk,
                     subvol, subvol->fops->flush, local->fd,
-                    local->rebalance.xdata);
+                    local->xattr_req);
 
         return 0;
 
@@ -785,6 +794,8 @@ dht_flush (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->call_cnt = 1;
 
@@ -908,7 +919,7 @@ dht_fsync2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND_COOKIE (frame, dht_fsync_cbk, subvol, subvol,
                            subvol->fops->fsync, local->fd,
-                           local->rebalance.flags, NULL);
+                           local->rebalance.flags, local->xattr_req);
 
         return 0;
 
@@ -935,6 +946,8 @@ dht_fsync (call_frame_t *frame, xlator_t *this, fd_t *fd, int datasync,
 
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->call_cnt = 1;
         local->rebalance.flags = datasync;
@@ -1025,7 +1038,7 @@ dht_lk2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 
         STACK_WIND (frame, dht_lk_cbk, subvol, subvol->fops->lk, local->fd,
                     local->rebalance.lock_cmd, &local->rebalance.flock,
-                    local->rebalance.xdata);
+                    local->xattr_req);
 
         return 0;
 
@@ -1060,6 +1073,8 @@ dht_lk (call_frame_t *frame, xlator_t *this,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->rebalance.flock = *flock;
         local->rebalance.lock_cmd = cmd;
diff --git a/xlators/cluster/dht/src/dht-inode-write.c b/xlators/cluster/dht/src/dht-inode-write.c
index 93755b9703a..825822a27e6 100644
--- a/xlators/cluster/dht/src/dht-inode-write.c
+++ b/xlators/cluster/dht/src/dht-inode-write.c
@@ -144,7 +144,7 @@ dht_writev2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
                            local->fd, local->rebalance.vector,
                            local->rebalance.count,
                            local->rebalance.offset, local->rebalance.flags,
-                           local->rebalance.iobref, NULL);
+                           local->rebalance.iobref, local->xattr_req);
 
         return 0;
 
@@ -181,7 +181,8 @@ dht_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
                 op_errno = EINVAL;
                 goto err;
         }
-
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         local->rebalance.vector = iov_dup (vector, count);
         local->rebalance.offset = off;
@@ -324,11 +325,11 @@ dht_truncate2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
         if (local->fop == GF_FOP_TRUNCATE) {
                 STACK_WIND_COOKIE (frame, dht_truncate_cbk, subvol, subvol,
                                    subvol->fops->truncate, &local->loc,
-                                   local->rebalance.offset, NULL);
+                                   local->rebalance.offset, local->xattr_req);
         } else {
                 STACK_WIND_COOKIE (frame, dht_truncate_cbk, subvol, subvol,
                                    subvol->fops->ftruncate, local->fd,
-                                   local->rebalance.offset, NULL);
+                                   local->rebalance.offset, local->xattr_req);
         }
 
         return 0;
@@ -367,6 +368,8 @@ dht_truncate (call_frame_t *frame, xlator_t *this, loc_t *loc, off_t offset,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_truncate_cbk, subvol, subvol,
                            subvol->fops->truncate, loc, offset, xdata);
@@ -407,6 +410,8 @@ dht_ftruncate (call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_truncate_cbk, subvol, subvol,
                            subvol->fops->ftruncate, fd, offset, xdata);
@@ -533,7 +538,7 @@ dht_fallocate2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 	STACK_WIND_COOKIE (frame, dht_fallocate_cbk, subvol, subvol,
                            subvol->fops->fallocate, local->fd,
                            local->rebalance.flags, local->rebalance.offset,
-		           local->rebalance.size, NULL);
+		           local->rebalance.size, local->xattr_req);
 
         return 0;
 
@@ -572,6 +577,8 @@ dht_fallocate(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t mode,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_fallocate_cbk, subvol, subvol,
                            subvol->fops->fallocate, fd, mode, offset, len,
@@ -699,7 +706,7 @@ dht_discard2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
 	STACK_WIND_COOKIE (frame, dht_discard_cbk, subvol, subvol,
                            subvol->fops->discard, local->fd,
                            local->rebalance.offset, local->rebalance.size,
-		           NULL);
+		           local->xattr_req);
 
         return 0;
 
@@ -737,6 +744,8 @@ dht_discard(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_discard_cbk, subvol, subvol,
                            subvol->fops->discard, fd, offset, len, xdata);
@@ -863,7 +872,7 @@ dht_zerofill2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
         STACK_WIND_COOKIE (frame, dht_zerofill_cbk, subvol, subvol,
                            subvol->fops->zerofill,
                            local->fd, local->rebalance.offset,
-                           local->rebalance.size, NULL);
+                           local->rebalance.size, local->xattr_req);
 
         return 0;
 
@@ -902,6 +911,8 @@ dht_zerofill(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         STACK_WIND_COOKIE (frame, dht_zerofill_cbk, subvol, subvol,
                            subvol->fops->zerofill, fd, offset, len, xdata);
@@ -1006,12 +1017,12 @@ dht_setattr2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
                 STACK_WIND_COOKIE (frame, dht_file_setattr_cbk, subvol,
                                    subvol, subvol->fops->setattr, &local->loc,
                                    &local->rebalance.stbuf, local->rebalance.flags,
-                                   NULL);
+                                   local->xattr_req);
         } else {
                 STACK_WIND_COOKIE (frame, dht_file_setattr_cbk, subvol,
                                    subvol, subvol->fops->fsetattr, local->fd,
                                    &local->rebalance.stbuf, local->rebalance.flags,
-                                   NULL);
+                                   local->xattr_req);
         }
 
         return 0;
@@ -1104,6 +1115,8 @@ dht_setattr (call_frame_t *frame, xlator_t *this, loc_t *loc,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         if (IA_ISREG (loc->inode->ia_type)) {
                 /* in the regular file _cbk(), we need to check for
@@ -1176,6 +1189,8 @@ dht_fsetattr (call_frame_t *frame, xlator_t *this, fd_t *fd, struct iatt *stbuf,
                 op_errno = EINVAL;
                 goto err;
         }
+        if (xdata)
+                local->xattr_req = dict_ref (xdata);
 
         if (IA_ISREG (fd->inode->ia_type)) {
                 /* in the regular file _cbk(), we need to check for