cluster/dht: Make rebalance honor min-free-disk

test:  Manual

created files of size 1K on 2 brick(of size 1GB) setup .
added a brick of size 16GB.
set min-free-disk to 12GB(so that first two bricks won't receive any files).
removed one of the 1st brick of size 1GB.

Logs from test:
[2017-04-12 08:52:08.196484] W [MSGID: 0] [dht-rebalance.c:895:__dht_check_free_space]
 0-test1-dht: Write will cross min-free-disk for file - /tile32 on subvol - test1-client-1.
Looking for new subvol.

[2017-04-12 08:52:08.196904] I [MSGID: 0] [dht-rebalance.c:925:__dht_check_free_space]
0-test1-dht: new target found - test1-client-2 for file - /tile32

 - Post migration we have two files. The new destination (/brick/1) has the data file
[root@vm1 ~]# ll /brick/1/tile32
-rw-r--r--. 2 root root 0 Apr 12 14:22 /brick/1/tile32

 - On the old target the linkto file is there with linkto xattr pointing to /brick/1
[root@vm1 ~]# ll /tmp/2/tile32
---------T. 2 root root 1000 Apr 12 14:22 /tmp/2/tile32
[root@vm1 ~]# getfattr -m . -de text /tmp/2/tile32
getfattr: Removing leading '/' from absolute path names
security.selinux="unconfined_u:object_r:user_tmp_t:s0"
trusted.gfid="����:Aс�#�/'b2"
trusted.glusterfs.dht.linkto="test1-client-2"

Marking ./tests/features/worm_sh.t as bad test.
Reason being, this patch failed on master branch as well and it has nothing
to do with rebalance/remove-brick.

BUG: 1441508
Change-Id: I90bae251cda3d957a49cdceda90cd08311a392fb
Signed-off-by: Susant Palai <spalai@redhat.com>
Reviewed-on: https://review.gluster.org/17034
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

1 files changed, 28 insertions, 3 deletions

diff --git a/xlators/cluster/dht/src/dht-diskusage.c b/xlators/cluster/dht/src/dht-diskusage.c
index 06957434c58..13698a9616d 100644
--- a/xlators/cluster/dht/src/dht-diskusage.c
+++ b/xlators/cluster/dht/src/dht-diskusage.c
@@ -81,7 +81,11 @@ dht_du_info_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 				conf->du_stats[i].avail_space   = bytes;
 				conf->du_stats[i].avail_inodes  = percent_inodes;
                                 conf->du_stats[i].chunks        = chunks;
-				gf_msg_debug (this->name, 0,
+                                conf->du_stats[i].total_blocks  = statvfs->f_blocks;
+                                conf->du_stats[i].avail_blocks  = statvfs->f_bavail;
+                                conf->du_stats[i].frsize        = statvfs->f_frsize;
+
+                                gf_msg_debug (this->name, 0,
 				              "subvolume '%s': avail_percent "
 					      "is: %.2f and avail_space "
                                               "is: %" PRIu64" and avail_inodes"
@@ -312,7 +316,7 @@ dht_free_disk_available_subvol (xlator_t *this, xlator_t *subvol,
         LOCK (&conf->subvolume_lock);
 	{
                 avail_subvol = dht_subvol_with_free_space_inodes(this, subvol,
-                                                                 layout);
+                                                                 layout, 0);
                 if(!avail_subvol)
                 {
                         avail_subvol = dht_subvol_maxspace_nonzeroinode(this,
@@ -373,12 +377,17 @@ out:
 /*Get subvolume which has both space and inodes more than the min criteria*/
 xlator_t *
 dht_subvol_with_free_space_inodes(xlator_t *this, xlator_t *subvol,
-                                  dht_layout_t *layout)
+                                  dht_layout_t *layout, uint64_t filesize)
 {
         int i = 0;
         double max = 0;
         double max_inodes = 0;
         int    ignore_subvol = 0;
+        uint64_t total_blocks = 0;
+        uint64_t avail_blocks = 0;
+        uint64_t frsize = 0;
+        double   post_availspace = 0;
+        double   post_percent = 0;
 
         xlator_t *avail_subvol = NULL;
         dht_conf_t *conf = NULL;
@@ -401,6 +410,9 @@ dht_subvol_with_free_space_inodes(xlator_t *this, xlator_t *subvol,
                                 max = conf->du_stats[i].avail_percent;
                                 max_inodes = conf->du_stats[i].avail_inodes;
                                 avail_subvol = conf->subvolumes[i];
+                                total_blocks = conf->du_stats[i].total_blocks;
+                                avail_blocks = conf->du_stats[i].avail_blocks;
+                                frsize       = conf->du_stats[i].frsize;
                         }
                 }
 
@@ -416,6 +428,19 @@ dht_subvol_with_free_space_inodes(xlator_t *this, xlator_t *subvol,
                 }
         }
 
+        if (avail_subvol) {
+                if (conf->disk_unit == 'p') {
+                        post_availspace = (avail_blocks * frsize) - filesize;
+                        post_percent = (post_availspace * 100) / (total_blocks * frsize);
+                        if (post_percent < conf->min_free_disk)
+                                avail_subvol = NULL;
+                }
+                if (conf->disk_unit != 'p') {
+                        if ((max - filesize) < conf->min_free_disk)
+                                avail_subvol = NULL;
+                }
+        }
+
         return avail_subvol;
 }