storage/posix: Add virtual xattr to fetch path from gfid

The gfid2path infra stores the "pargfid/bname" as on xattr
value for each non directory entry. Hardlinks would have a
separate xattr. This xattr key is internal and is not
exposed to applications.  A virtual xattr is exposed for
the applications to fetch the path from gfid.

Internal xattr:
trusted.gfid2path.<xxhash>

Virtual xattr:
glusterfs.gfidtopath

getfattr -h -n glusterfs.gfidtopath /<aux-mnt>/.gfid/<gfid>

If there are hardlinks, it returns all the paths separated
by ':'.

A volume set option is introduced to change the delimiter
to required string of max length 7.

gluster vol set gfid2path-separator ":::"

Updates: #139
Change-Id: Ie3b0c3fd8bd5333c4a27410011e608333918c02a
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: https://review.gluster.org/17785
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Krutika Dhananjay <kdhananj@redhat.com>

2 files changed, 80 insertions, 0 deletions

diff --git a/tests/gfid2path/get-gfid-to-path.t b/tests/gfid2path/get-gfid-to-path.t
new file mode 100644
index 00000000000..71c2c2fab70
--- /dev/null
+++ b/tests/gfid2path/get-gfid-to-path.t
@@ -0,0 +1,75 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+. $(dirname $0)/../afr.rc
+
+cleanup;
+
+TEST glusterd
+TEST pidof glusterd
+
+## Create a 1*2 volume
+TEST $CLI volume create $V0 replica 2 $H0:$B0/${V0}{0,1}
+EXPECT "$V0" volinfo_field $V0 'Volume Name';
+EXPECT 'Created' volinfo_field $V0 'Status';
+
+## Start the volume
+TEST $CLI volume start $V0
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" glustershd_up_status
+EXPECT_WITHIN $CHILD_UP_TIMEOUT "1" afr_child_up_status_in_shd $V0 0
+EXPECT_WITHIN $CHILD_UP_TIMEOUT "1" afr_child_up_status_in_shd $V0 1
+
+## enable gfid2path
+TEST $CLI volume set $V0 gfid2path enable
+
+## Mount the volume
+TEST $GFS --volfile-server=$H0 --aux-gfid-mount --volfile-id=$V0 $M0;
+
+root_gfid="00000000-0000-0000-0000-000000000001"
+
+#Check for ROOT
+EXPECT "/" get_gfid2path $M0/.gfid/$root_gfid
+
+#CREATE
+fname=$M0/file1
+touch $fname;
+
+#Get gfid of file1
+gfid=$(getfattr -h --only-values -n glusterfs.gfid.string $M0/file1)
+
+#Get path from virt xattr
+EXPECT "/file1" get_gfid2path $M0/.gfid/$gfid
+
+#Create hardlink and get path
+ln $fname $M0/hl_file1
+EXPECT "/file1" get_gfid2path $M0/.gfid/$gfid
+EXPECT "/hl_file1" get_gfid2path $M0/.gfid/$gfid
+
+#Rename and get path
+mv $fname $M0/rn_file1
+EXPECT "/hl_file1" get_gfid2path $M0/.gfid/$gfid
+EXPECT "/rn_file1" get_gfid2path $M0/.gfid/$gfid
+
+#Create symlink and get path
+ln -s $fname $M0/sym_file1
+gfid=$(getfattr -h --only-values -n glusterfs.gfid.string $M0/sym_file1)
+EXPECT "/sym_file1" get_gfid2path $M0/.gfid/$gfid
+
+#Create dir and get path
+mkdir -p $M0/dir1/dir2
+gfid=$(getfattr -h --only-values -n glusterfs.gfid.string $M0/dir1/dir2)
+EXPECT "/dir1/dir2" get_gfid2path $M0/.gfid/$gfid
+
+#Create file under dir2 and get path
+touch $M0/dir1/dir2/file1
+gfid=$(getfattr -h --only-values -n glusterfs.gfid.string $M0/dir1/dir2/file1)
+EXPECT "/dir1/dir2/file1" get_gfid2path $M0/.gfid/$gfid
+
+#Create hardlink under dir2 and get path
+ln $M0/dir1/dir2/file1 $M0/dir1/hl_file1
+gfid=$(getfattr -h --only-values -n glusterfs.gfid.string $M0/dir1/dir2/file1)
+EXPECT "/dir1/dir2/file1" get_gfid2path $M0/.gfid/$gfid
+EXPECT "/dir1/hl_file1" get_gfid2path $M0/.gfid/$gfid
+
+cleanup;
diff --git a/tests/volume.rc b/tests/volume.rc
index 402bb9dbf19..369e5a706c6 100644
--- a/tests/volume.rc
+++ b/tests/volume.rc
@@ -359,6 +359,11 @@ function get_text_xattr {
         getfattr -h -d -m. -e text $path 2>/dev/null | grep -a $key | cut -f2 -d'='
 }
 
+function get_gfid2path {
+        local path=$1
+        getfattr -h --only-values -n glusterfs.gfidtopath $path 2>/dev/null
+}
+
 function get_xattr_key {
         local key=$1
         local path=$2