From d4ddb41fc6868d41f38d9a4bec0f4ad7d332add9 Mon Sep 17 00:00:00 2001
From: Jeffrey Cody <jcody@redhat.com>
Date: Tue, 2 Sep 2014 19:34:06 +0200
Subject: [PATCH 3/6] gluster: Add discard support for GlusterFS block driver.

Message-id: <6b5e10e9b95a3030bb19540324915e0b774bd5bb.1409686386.git.jcody@redhat.com>
Patchwork-id: 60815
O-Subject: [PATCH qemu-kvm-rhev RHEL7.1] gluster: Add discard support for GlusterFS block driver.
Bugzilla: 1136534
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>

From: Bharata B Rao <bharata@linux.vnet.ibm.com>

Implement bdrv_aio_discard for gluster.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 0c14fb47ece5ef42d7a0a4b3e8e43e022b375720)
Signed-off-by: Jeff Cody <jcody@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block/gluster.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
 configure       |    8 ++++++++
 2 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/block/gluster.c b/block/gluster.c
index f43d3a6..da43d0c 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -633,6 +633,39 @@ out:
     return NULL;
 }
 
+#ifdef CONFIG_GLUSTERFS_DISCARD
+static BlockDriverAIOCB *qemu_gluster_aio_discard(BlockDriverState *bs,
+        int64_t sector_num, int nb_sectors, BlockDriverCompletionFunc *cb,
+        void *opaque)
+{
+    int ret;
+    GlusterAIOCB *acb;
+    BDRVGlusterState *s = bs->opaque;
+    size_t size;
+    off_t offset;
+
+    offset = sector_num * BDRV_SECTOR_SIZE;
+    size = nb_sectors * BDRV_SECTOR_SIZE;
+
+    acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
+    acb->size = 0;
+    acb->ret = 0;
+    acb->finished = NULL;
+    s->qemu_aio_count++;
+
+    ret = glfs_discard_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
+    if (ret < 0) {
+        goto out;
+    }
+    return &acb->common;
+
+out:
+    s->qemu_aio_count--;
+    qemu_aio_release(acb);
+    return NULL;
+}
+#endif
+
 static int64_t qemu_gluster_getlength(BlockDriverState *bs)
 {
     BDRVGlusterState *s = bs->opaque;
@@ -707,6 +740,9 @@ static BlockDriver bdrv_gluster = {
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
+#ifdef CONFIG_GLUSTERFS_DISCARD
+    .bdrv_aio_discard             = qemu_gluster_aio_discard,
+#endif
     .create_options               = qemu_gluster_create_options,
 };
 
@@ -727,6 +763,9 @@ static BlockDriver bdrv_gluster_tcp = {
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
+#ifdef CONFIG_GLUSTERFS_DISCARD
+    .bdrv_aio_discard             = qemu_gluster_aio_discard,
+#endif
     .create_options               = qemu_gluster_create_options,
 };
 
@@ -747,6 +786,9 @@ static BlockDriver bdrv_gluster_unix = {
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
+#ifdef CONFIG_GLUSTERFS_DISCARD
+    .bdrv_aio_discard             = qemu_gluster_aio_discard,
+#endif
     .create_options               = qemu_gluster_create_options,
 };
 
@@ -767,6 +809,9 @@ static BlockDriver bdrv_gluster_rdma = {
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
+#ifdef CONFIG_GLUSTERFS_DISCARD
+    .bdrv_aio_discard             = qemu_gluster_aio_discard,
+#endif
     .create_options               = qemu_gluster_create_options,
 };
 
diff --git a/configure b/configure
index 0c666e5..fb0c839 100755
--- a/configure
+++ b/configure
@@ -238,6 +238,7 @@ libiscsi=""
 coroutine=""
 seccomp=""
 glusterfs=""
+glusterfs_discard="no"
 virtio_blk_data_plane=""
 gtk=""
 gtkabi="2.0"
@@ -2644,6 +2645,9 @@ EOF
   glusterfs_libs="-lgfapi -lgfrpc -lgfxdr"
   if compile_prog "" "$glusterfs_libs" ; then
     glusterfs=yes
+    if $pkg_config --atleast-version=5 glusterfs-api >/dev/null 2>&1; then
+      glusterfs_discard="yes"
+    fi
   else
     if test "$glusterfs" = "yes" ; then
       feature_not_found "GlusterFS backend support"
@@ -4025,6 +4029,10 @@ if test "$glusterfs" = "yes" ; then
   echo "GLUSTERFS_LIBS=$glusterfs_libs" >> $config_host_mak
 fi
 
+if test "$glusterfs_discard" = "yes" ; then
+  echo "CONFIG_GLUSTERFS_DISCARD=y" >> $config_host_mak
+fi
+
 if test "$libssh2" = "yes" ; then
   echo "CONFIG_LIBSSH2=y" >> $config_host_mak
   echo "LIBSSH2_CFLAGS=$libssh2_cflags" >> $config_host_mak
-- 
1.7.1