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From b24bec7c4477946f17bf4628608b60d4960b4247 Mon Sep 17 00:00:00 2001
From: Jeffrey Cody <jcody@redhat.com>
Date: Thu, 6 Mar 2014 21:13:15 +0100
Subject: [PATCH 05/16] block: gluster - add reopen support.

RH-Author: Jeffrey Cody <jcody@redhat.com>
Message-id: <2f1e357ca27ef45d16e62fbe44b0ce9cef2602fe.1394129674.git.jcody@redhat.com>
Patchwork-id: 58041
O-Subject: [RHEL7 qemu-kvm PATCH 2/2] block: gluster - add reopen support.
Bugzilla: 1031526
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>

Gluster does parse open flags in its .bdrv_open() implementation,
and the .bdrv_reopen_* implementations need to do the same.

A new gluster connection to the image file to be created is established
in the .bdrv_reopen_prepare(), and the image file opened with the new
flags.

If this is successful, then the old image file is closed, and the
old connection torn down. The relevant structure pointers in the gluster
state structure are updated to the new connection.

If it is not successful, then the new file handle and connection is
abandoned (if it exists), while the old connection is not modified at
all.

With reopen supported, block-commit (and offline commit) is now also
supported for image files whose base image uses the native gluster
protocol driver.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit adccfbcd6020e928db93b2b4faf0dbd05ffbe016)

Conflicts:
	block/gluster.c

RHEL7 Note:  Conflict was in contextual information, as RHEL7 does not
             have gluster zerofill support.
---
 block/gluster.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block/gluster.c |  102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 102 insertions(+), 0 deletions(-)

diff --git a/block/gluster.c b/block/gluster.c
index 95cb05a..f43d3a6 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -376,6 +376,96 @@ out:
     return ret;
 }
 
+typedef struct BDRVGlusterReopenState {
+    struct glfs *glfs;
+    struct glfs_fd *fd;
+} BDRVGlusterReopenState;
+
+
+static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
+                                       BlockReopenQueue *queue, Error **errp)
+{
+    int ret = 0;
+    BDRVGlusterReopenState *reop_s;
+    GlusterConf *gconf = NULL;
+    int open_flags = 0;
+
+    assert(state != NULL);
+    assert(state->bs != NULL);
+
+    state->opaque = g_malloc0(sizeof(BDRVGlusterReopenState));
+    reop_s = state->opaque;
+
+    qemu_gluster_parse_flags(state->flags, &open_flags);
+
+    gconf = g_malloc0(sizeof(GlusterConf));
+
+    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename);
+    if (reop_s->glfs == NULL) {
+        ret = -errno;
+        goto exit;
+    }
+
+    reop_s->fd = glfs_open(reop_s->glfs, gconf->image, open_flags);
+    if (reop_s->fd == NULL) {
+        /* reops->glfs will be cleaned up in _abort */
+        ret = -errno;
+        goto exit;
+    }
+
+exit:
+    /* state->opaque will be freed in either the _abort or _commit */
+    qemu_gluster_gconf_free(gconf);
+    return ret;
+}
+
+static void qemu_gluster_reopen_commit(BDRVReopenState *state)
+{
+    BDRVGlusterReopenState *reop_s = state->opaque;
+    BDRVGlusterState *s = state->bs->opaque;
+
+
+    /* close the old */
+    if (s->fd) {
+        glfs_close(s->fd);
+    }
+    if (s->glfs) {
+        glfs_fini(s->glfs);
+    }
+
+    /* use the newly opened image / connection */
+    s->fd         = reop_s->fd;
+    s->glfs       = reop_s->glfs;
+
+    g_free(state->opaque);
+    state->opaque = NULL;
+
+    return;
+}
+
+
+static void qemu_gluster_reopen_abort(BDRVReopenState *state)
+{
+    BDRVGlusterReopenState *reop_s = state->opaque;
+
+    if (reop_s == NULL) {
+        return;
+    }
+
+    if (reop_s->fd) {
+        glfs_close(reop_s->fd);
+    }
+
+    if (reop_s->glfs) {
+        glfs_fini(reop_s->glfs);
+    }
+
+    g_free(state->opaque);
+    state->opaque = NULL;
+
+    return;
+}
+
 static int qemu_gluster_create(const char *filename,
         QEMUOptionParameter *options, Error **errp)
 {
@@ -605,6 +695,9 @@ static BlockDriver bdrv_gluster = {
     .protocol_name                = "gluster",
     .instance_size                = sizeof(BDRVGlusterState),
     .bdrv_file_open               = qemu_gluster_open,
+    .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
+    .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
+    .bdrv_reopen_abort            = qemu_gluster_reopen_abort,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
@@ -622,6 +715,9 @@ static BlockDriver bdrv_gluster_tcp = {
     .protocol_name                = "gluster+tcp",
     .instance_size                = sizeof(BDRVGlusterState),
     .bdrv_file_open               = qemu_gluster_open,
+    .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
+    .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
+    .bdrv_reopen_abort            = qemu_gluster_reopen_abort,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
@@ -639,6 +735,9 @@ static BlockDriver bdrv_gluster_unix = {
     .protocol_name                = "gluster+unix",
     .instance_size                = sizeof(BDRVGlusterState),
     .bdrv_file_open               = qemu_gluster_open,
+    .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
+    .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
+    .bdrv_reopen_abort            = qemu_gluster_reopen_abort,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
@@ -656,6 +755,9 @@ static BlockDriver bdrv_gluster_rdma = {
     .protocol_name                = "gluster+rdma",
     .instance_size                = sizeof(BDRVGlusterState),
     .bdrv_file_open               = qemu_gluster_open,
+    .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
+    .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
+    .bdrv_reopen_abort            = qemu_gluster_reopen_abort,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
-- 
1.7.1