cluster/dht: Delete invalid linkto files in rmdir

rm -rf <dir> fails on dirs which contain linkto files
that point to themselves because dht incorrectly thought
that they were cached files after looking them up.
The fix now treats them as invalid linkto files
and deletes them.

Change-Id: I376c72a5309714ee339c74485e02cfb4e29be643
fixes: bz#1667804
Signed-off-by: N Balachandran <nbalacha@redhat.com>

2 files changed, 67 insertions, 1 deletions

diff --git a/tests/bugs/distribute/bug-1667804.t b/tests/bugs/distribute/bug-1667804.t
new file mode 100644
index 00000000000..3f7c43111d7
--- /dev/null
+++ b/tests/bugs/distribute/bug-1667804.t
@@ -0,0 +1,63 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+. $(dirname $0)/../../dht.rc
+
+function confirm_all_linkto_files ()
+{
+   inpath=$1
+   for infile in $inpath/*
+   do
+      echo $infile
+      ret1=$(is_dht_linkfile $infile)
+      if [ "$ret1" -eq 0 ]; then
+        echo "$infile is not a linkto file"
+        echo 0
+        return
+      fi
+   done
+   echo  1
+}
+
+cleanup;
+
+#Basic checks
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume info
+
+#Create a distributed volume
+TEST $CLI volume create $V0 $H0:$B0/${V0}{1..2};
+TEST $CLI volume start $V0
+
+# Mount FUSE
+TEST glusterfs -s $H0 --volfile-id $V0 $M0
+
+#Create files and rename them in order to create linkto files
+TEST mkdir -p $M0/dir0/dir1
+TEST touch $M0/dir0/dir1/file-{1..50}
+
+for i in {1..50}; do
+    mv $M0/dir0/dir1/file-$i $M0/dir0/dir1/nfile-$i;
+done
+
+#Remove the second brick to force the creation of linkto files
+#on the removed brick
+
+TEST $CLI volume remove-brick $V0 $H0:$B0/${V0}2 start
+EXPECT_WITHIN $REBALANCE_TIMEOUT "completed" remove_brick_status_completed_field "$V0 $H0:$B0/${V0}2"
+TEST $CLI volume remove-brick $V0 $H0:$B0/${V0}2 stop
+
+EXPECT "1" confirm_all_linkto_files $B0/${V0}2/dir0/dir1
+
+#Modify the xattrs of the linkto files on the removed brick to point to itself.
+
+target=$(cat $M0/.meta/graphs/active/$V0-dht/subvolumes/1/name)
+
+setfattr -n trusted.glusterfs.dht.linkto -v "$target\0" $B0/${V0}2/dir0/dir1/nfile*
+
+
+TEST rm -rf $M0/dir0
+
+cleanup;
diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 4bbecc708ad..912e3c6e104 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -10029,7 +10029,10 @@ dht_rmdir_is_subvol_empty(call_frame_t *frame, xlator_t *this,
                      lookup_local->loc.path, src->name, gfid);
 
         subvol = dht_linkfile_subvol(this, NULL, &trav->d_stat, trav->dict);
-        if (!subvol) {
+        if (!subvol || (subvol == src)) {
+            /* we need to delete the linkto file if it does not have a
+             * valid subvol or it points to itself.
+             */
             gf_msg(this->name, GF_LOG_INFO, 0, DHT_MSG_INVALID_LINKFILE,
                    "Linkfile does not have link subvolume. "
                    "path = %s, gfid = %s",