dht: report constant directory size

Directory size is meaningless.  Every filesystem has its own
unpredictable way of increasing or decreasing it, based on internal data
structures and even transient conditions.  Some filesystems (e.g. ext4)
never decrease it at all.  Others (e.g. btrfs) don't even report it.
Very few programs look at it, and those that do are broken.
Unfortunately, one such program is GNU tar, which will complain when it
sees different values because at different times we got the value from
different DHT subvolumes.  To avoid such problems, just report a
constant value.

Backport of http://review.gluster.org/#/c/13770/

> Change-Id: Id64ce917c75b5f7ff50cb55b6e997f3b3556e7e3
> BUG: 1302948
> Original-author: Shyam <srangana@redhat.com>
> Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
> Signed-off-by: N Balachandran <nbalacha@redhat.com>
> Reviewed-on: http://review.gluster.org/13770
> Smoke: Gluster Build System <jenkins@build.gluster.com>
> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
> Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
> Reviewed-by: Vijay Bellur <vbellur@redhat.com>

Change-Id: Id64ce917c75b5f7ff50cb55b6e997f3b3556e7e3
BUG: 1312721
Original-author: Shyam <srangana@redhat.com>
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Signed-off-by: N Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/13831
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

4 files changed, 81 insertions, 1 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index fc7b272d51c..7755eba9887 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -31,6 +31,8 @@
 
 int run_defrag = 0;
 
+
+
 int dht_link2 (xlator_t *this, xlator_t *dst_node, call_frame_t *frame,
                int ret);
 
@@ -42,6 +44,21 @@ int
 dht_setxattr2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame,
                int ret);
 
+
+/* Sets the blocks and size values to fixed values. This is to be called
+ * only for dirs. The caller is responsible for checking the type
+ */
+int32_t dht_set_fixed_dir_stat (struct iatt *stat)
+{
+        if (stat) {
+                stat->ia_blocks = DHT_DIR_STAT_BLOCKS;
+                stat->ia_size = DHT_DIR_STAT_SIZE;
+                return 0;
+        }
+        return -1;
+}
+
+
 int
 dht_aggregate_quota_xattr (dict_t *dst, char *key, data_t *value)
 {
@@ -210,6 +227,7 @@ dht_lookup_selfheal_cbk (call_frame_t *frame, void *cookie,
         }
 
         DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+        dht_set_fixed_dir_stat (&local->postparent);
 
         DHT_STACK_UNWIND (lookup, frame, ret, local->op_errno, local->inode,
                           &local->stbuf, local->xattr, &local->postparent);
@@ -369,6 +387,7 @@ cleanup:
 
         }
 done:
+        dht_set_fixed_dir_stat (&local->postparent);
         DHT_STACK_UNWIND (lookup, main_frame, local->op_ret, local->op_errno,
                           local->inode, &local->stbuf, local->xattr,
                           &local->postparent);
@@ -719,6 +738,7 @@ unlock:
                 }
 
                 DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+                dht_set_fixed_dir_stat (&local->postparent);
                 DHT_STACK_UNWIND (lookup, frame, local->op_ret, local->op_errno,
                                   local->inode, &local->stbuf, local->xattr,
                                   &local->postparent);
@@ -976,6 +996,7 @@ cont:
                 }
 
                 DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+                dht_set_fixed_dir_stat (&local->postparent);
                 DHT_STACK_UNWIND (lookup, frame, local->op_ret, local->op_errno,
                                   local->inode, &local->stbuf, local->xattr,
                                   &local->postparent);
@@ -1046,6 +1067,8 @@ unwind:
                 dht_linkfile_attr_heal (frame, this);
 
 
+        dht_set_fixed_dir_stat (&local->postparent);
+
         DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
         DHT_STACK_UNWIND (lookup, frame, local->op_ret, local->op_errno,
                           local->inode, &local->stbuf, local->xattr,
@@ -1511,6 +1534,7 @@ preset_layout:
                 }
 
                 DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+                dht_set_fixed_dir_stat (&local->postparent);
                 DHT_STACK_UNWIND (lookup, frame, local->op_ret,
                                   local->op_errno, local->inode,
                                   &local->stbuf, local->xattr,
@@ -1547,6 +1571,7 @@ preset_layout:
                 }
 
                 DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+                dht_set_fixed_dir_stat (&local->postparent);
                 DHT_STACK_UNWIND (lookup, frame, local->op_ret,
                                   local->op_errno, local->inode,
                                   &local->stbuf, local->xattr,
@@ -1567,6 +1592,7 @@ preset_layout:
 
 unwind_hashed_and_cached:
         DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+        dht_set_fixed_dir_stat (&local->postparent);
         DHT_STACK_UNWIND (lookup, frame, local->op_ret, local->op_errno,
                           local->loc.inode, &local->stbuf, local->xattr,
                           &local->postparent);
@@ -1912,6 +1938,7 @@ dht_lookup_linkfile_cbk (call_frame_t *frame, void *cookie,
 
 unwind:
         DHT_STRIP_PHASE1_FLAGS (stbuf);
+        dht_set_fixed_dir_stat (postparent);
         DHT_STACK_UNWIND (lookup, frame, op_ret, op_errno, inode, stbuf, xattr,
                           postparent);
 
@@ -2158,6 +2185,7 @@ out:
         }
 
         DHT_STRIP_PHASE1_FLAGS (stbuf);
+        dht_set_fixed_dir_stat (postparent);
         DHT_STACK_UNWIND (lookup, frame, op_ret, op_errno, inode, stbuf, xattr,
                           postparent);
 err:
@@ -2473,7 +2501,8 @@ dht_unlink_linkfile_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 unlock:
         UNLOCK (&frame->lock);
 
-
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
         DHT_STACK_UNWIND (unlink, frame, local->op_ret, local->op_errno,
                           &local->preparent, &local->postparent, xdata);
 
@@ -2539,6 +2568,8 @@ unlock:
                 }
         }
 
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
         DHT_STACK_UNWIND (unlink, frame, local->op_ret, local->op_errno,
                           &local->preparent, &local->postparent, xdata);
 
@@ -4712,6 +4743,8 @@ list:
                    currently possible only for non-directories, so for
                    directories don't set entry inodes */
                 if (IA_ISDIR(entry->d_stat.ia_type)) {
+                        entry->d_stat.ia_blocks = DHT_DIR_STAT_BLOCKS;
+                        entry->d_stat.ia_size = DHT_DIR_STAT_SIZE;
                         if (orig_entry->inode) {
                                 dht_inode_ctx_time_update (orig_entry->inode,
                                                            this, &entry->d_stat,
@@ -5164,6 +5197,8 @@ out:
          * See dht_iatt_merge for reference.
          */
         DHT_STRIP_PHASE1_FLAGS (stbuf);
+        dht_set_fixed_dir_stat (postparent);
+        dht_set_fixed_dir_stat (preparent);
 
         if (local && local->lock.locks) {
                 /* store op_errno for failure case*/
@@ -5774,6 +5809,8 @@ dht_link_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 out:
         DHT_STRIP_PHASE1_FLAGS (stbuf);
 
+        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);
 
@@ -5798,6 +5835,9 @@ dht_link2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
                  * pass on the original mode bits so the higher DHT layer
                  * can handle this.
                  */
+                dht_set_fixed_dir_stat (&local->preparent);
+                dht_set_fixed_dir_stat (&local->postparent);
+
                 DHT_STACK_UNWIND (link, frame, local->op_ret, op_errno,
                                   local->inode,
                                   &local->stbuf, &local->preparent,
@@ -5815,6 +5855,8 @@ dht_link2 (xlator_t *this, xlator_t *subvol, call_frame_t *frame, int ret)
          * migrating subvol, which could be the new hashed subvol */
         if (local->link_subvol == subvol) {
                 DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+                dht_set_fixed_dir_stat (&local->preparent);
+                dht_set_fixed_dir_stat (&local->postparent);
                 DHT_STACK_UNWIND (link, frame, 0, 0, local->inode,
                                   &local->stbuf, &local->preparent,
                                   &local->postparent, NULL);
@@ -5858,6 +5900,8 @@ dht_link_linkfile_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
 err:
         DHT_STRIP_PHASE1_FLAGS (stbuf);
+        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);
 
@@ -5980,6 +6024,8 @@ dht_create_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 out:
 
         DHT_STRIP_PHASE1_FLAGS (stbuf);
+        dht_set_fixed_dir_stat (preparent);
+        dht_set_fixed_dir_stat (postparent);
 
         if (local && local->lock.locks) {
                 /* store op_errno for failure case*/
@@ -6491,6 +6537,9 @@ dht_mkdir_selfheal_cbk (call_frame_t *frame, void *cookie,
         local = frame->local;
         layout = local->selfheal.layout;
 
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
+
         if (op_ret == 0) {
                 dht_layout_set (this, local->inode, layout);
 
@@ -6739,6 +6788,9 @@ dht_rmdir_selfheal_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
         local = frame->local;
 
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
+
         DHT_STACK_UNWIND (rmdir, frame, local->op_ret, local->op_errno,
                           &local->preparent, &local->postparent, NULL);
 
@@ -6816,6 +6868,9 @@ unlock:
                                                            1);
                         }
 
+                        dht_set_fixed_dir_stat (&local->preparent);
+                        dht_set_fixed_dir_stat (&local->postparent);
+
                         DHT_STACK_UNWIND (rmdir, frame, local->op_ret,
                                           local->op_errno, &local->preparent,
                                           &local->postparent, NULL);
@@ -6918,6 +6973,9 @@ unlock:
 
                         }
 
+                        dht_set_fixed_dir_stat (&local->preparent);
+                        dht_set_fixed_dir_stat (&local->postparent);
+
                         DHT_STACK_UNWIND (rmdir, frame, local->op_ret,
                                           local->op_errno, &local->preparent,
                                           &local->postparent, NULL);
@@ -6985,6 +7043,9 @@ dht_rmdir_do (call_frame_t *frame, xlator_t *this)
         return 0;
 
 err:
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
+
         DHT_STACK_UNWIND (rmdir, frame, local->op_ret, local->op_errno,
                           &local->preparent, &local->postparent, NULL);
         return 0;
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index 31b8b6804b7..53d1489e41b 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -36,6 +36,9 @@
 #define DHT_LAYOUT_HASH_INVALID     1
 #define TIERING_MIGRATION_KEY       "tiering.migration"
 
+#define DHT_DIR_STAT_BLOCKS          8
+#define DHT_DIR_STAT_SIZE            4096
+
 #include <fnmatch.h>
 
 typedef int (*dht_selfheal_dir_cbk_t) (call_frame_t *frame, void *cookie,
@@ -1172,4 +1175,8 @@ dht_fd_ctx_destroy (xlator_t *this, fd_t *fd);
 
 int32_t
 dht_release (xlator_t *this, fd_t *fd);
+
+
+int32_t
+dht_set_fixed_dir_stat (struct iatt *stat);
 #endif/* _DHT_H */
diff --git a/xlators/cluster/dht/src/dht-helper.c b/xlators/cluster/dht/src/dht-helper.c
index d980a4d451f..df31cdbb047 100644
--- a/xlators/cluster/dht/src/dht-helper.c
+++ b/xlators/cluster/dht/src/dht-helper.c
@@ -920,6 +920,10 @@ dht_iatt_merge (xlator_t *this, struct iatt *to,
         to->ia_blksize  = from->ia_blksize;
         to->ia_blocks  += from->ia_blocks;
 
+        if (IA_ISDIR (from->ia_type)) {
+                to->ia_blocks = DHT_DIR_STAT_BLOCKS;
+                to->ia_size = DHT_DIR_STAT_SIZE;
+        }
         set_if_greater (to->ia_uid, from->ia_uid);
         set_if_greater (to->ia_gid, from->ia_gid);
 
@@ -2259,6 +2263,8 @@ dht_heal_full_path_done (int op_ret, call_frame_t *heal_frame, void *data)
         main_frame = local->main_frame;
         local->main_frame = NULL;
 
+        dht_set_fixed_dir_stat (&local->postparent);
+
         DHT_STACK_UNWIND (lookup, main_frame, 0, 0,
                           local->inode, &local->stbuf, local->xattr,
                           &local->postparent);
diff --git a/xlators/cluster/dht/src/dht-rename.c b/xlators/cluster/dht/src/dht-rename.c
index dc879b0e100..79b87069d2b 100644
--- a/xlators/cluster/dht/src/dht-rename.c
+++ b/xlators/cluster/dht/src/dht-rename.c
@@ -162,6 +162,7 @@ unwind:
         WIPE (&local->postparent);
 
         DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+
         DHT_STACK_UNWIND (rename, frame, local->op_ret, local->op_errno,
                           &local->stbuf, &local->preoldparent,
                           &local->postoldparent,
@@ -426,6 +427,11 @@ dht_rename_unlock_cbk (call_frame_t *frame, void *cookie,
         local = frame->local;
 
         DHT_STRIP_PHASE1_FLAGS (&local->stbuf);
+        dht_set_fixed_dir_stat (&local->preoldparent);
+        dht_set_fixed_dir_stat (&local->postoldparent);
+        dht_set_fixed_dir_stat (&local->preparent);
+        dht_set_fixed_dir_stat (&local->postparent);
+
         DHT_STACK_UNWIND (rename, frame, local->op_ret, local->op_errno,
                           &local->stbuf, &local->preoldparent,
                           &local->postoldparent, &local->preparent,