[Qemu-devel] [PATCH 0/3] block/gluster: add support for multiple gluster servers

[Qemu-devel] [PATCH 0/3] block/gluster: add support for multiple gluster servers

[Prasanna Kumar Kalever]

Prasanna Kumar Kalever (3):
  block/gluster: rename [server, volname, image] -> [host, volume, path]
  block/gluster: code cleanup
  block/gluster: add support for multiple gluster servers

 block/gluster.c      | 589 ++++++++++++++++++++++++++++++++++++++++-----------
 qapi/block-core.json |  64 +++++-
 2 files changed, 523 insertions(+), 130 deletions(-)

-- 
2.1.0

[Qemu-devel] [PATCH v12 3/3] block/gluster: add support for multiple gluster servers

[Prasanna Kumar Kalever]

This patch adds a way to specify multiple volfile servers to the gluster
block backend of QEMU with tcp|rdma transport types and their port numbers.

Problem:

Currently VM Image on gluster volume is specified like this:

file=gluster[+tcp]://host[:port]/testvol/a.img

Assuming we have three hosts in trusted pool with replica 3 volume
in action and unfortunately host (mentioned in the command above) went down
for some reason, since the volume is replica 3 we now have other 2 hosts
active from which we can boot the VM.

But currently there is no mechanism to pass the other 2 gluster host
addresses to qemu.

Solution:

New way of specifying VM Image on gluster volume with volfile servers:
(We still support old syntax to maintain backward compatibility)

Basic command line syntax looks like:

Pattern I:
 -drive driver=gluster,
        volume=testvol,path=/path/a.raw,
        servers.0.host=1.2.3.4,
       [servers.0.port=24007,]
       [servers.0.transport=tcp,]
        servers.1.host=5.6.7.8,
       [servers.1.port=24008,]
       [servers.1.transport=rdma,] ...

Pattern II:
 'json:{"driver":"qcow2","file":{"driver":"gluster",
       "volume":"testvol","path":"/path/a.qcow2",
       "servers":[{tuple0},{tuple1}, ...{tupleN}]}}'

   driver      => 'gluster' (protocol name)
   volume      => name of gluster volume where our VM image resides
   path        => absolute path of image in gluster volume

  {tuple}      => {"host":"1.2.3.4"[,"port":"24007","transport":"tcp"]}

   host        => host address (hostname/ipv4/ipv6 addresses)
   port        => port number on which glusterd is listening. (default 24007)
   transport   => transport type used to connect to gluster management daemon,
                   it can be tcp|rdma (default 'tcp')

Examples:
1.
 -drive driver=qcow2,file.driver=gluster,
        file.volume=testvol,file.path=/path/a.qcow2,
        file.servers.0.host=1.2.3.4,
        file.servers.0.port=24007,
        file.servers.0.transport=tcp,
        file.servers.1.host=5.6.7.8,
        file.servers.1.port=24008,
        file.servers.1.transport=rdma
2.
 'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
         "path":"/path/a.qcow2","servers":
         [{"host":"1.2.3.4","port":"24007","transport":"tcp"},
          {"host":"4.5.6.7","port":"24008","transport":"rdma"}] } }'

This patch gives a mechanism to provide all the server addresses, which are in
replica set, so in case host1 is down VM can still boot from any of the
active hosts.

This is equivalent to the backup-volfile-servers option supported by
mount.glusterfs (FUSE way of mounting gluster volume)

This patch depends on a recent fix in libgfapi raised as part of this work:
http://review.gluster.org/#/c/12114/

Credits: Sincere thanks to Kevin Wolf <kwolf@redhat.com> and
"Deepak C Shetty" <deepakcs@redhat.com> for inputs and all their support

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
---
v1:
multiple host addresses but common port number and transport type
pattern: URI syntax with query (?) delimitor
syntax:
    file=gluster[+transport-type]://host1:24007/testvol/a.img\
         ?servers=host2&servers=host3

v2:
multiple host addresses each have their own port number, but all use
                                                         common transport type
pattern: URI syntax  with query (?) delimiter
syntax:
    file=gluster[+transport-type]://[host[:port]]/testvol/a.img\
         [?servers=host1[:port]\
          &servers=host2[:port]]

v3:
multiple host addresses each have their own port number and transport type
pattern: changed to json
syntax:
    'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
           "path":"/path/a.qcow2","servers":
         [{"host":"1.2.3.4","port":"24007","transport":"tcp"},
          {"host":"4.5.6.7","port":"24008","transport":"rdma"}] } }'

v4, v5:
address comments from "Eric Blake" <eblake@redhat.com>
renamed:
'backup-volfile-servers' -> 'volfile-servers'

v6:
address comments from Peter Krempa <pkrempa@redhat.com>
renamed:
 'volname'    ->  'volume'
 'image-path' ->  'path'
 'server'     ->  'host'

v7:
fix for v6 (initialize num_servers to 1 and other typos)

v8:
split patch set v7 into series of 3 as per Peter Krempa <pkrempa@redhat.com>
review comments

v9:
reorder the series of patches addressing "Eric Blake" <eblake@redhat.com>
review comments

v10:
fix mem-leak as per Peter Krempa <pkrempa@redhat.com> review comments

v11:
using qapi-types* defined structures as per "Eric Blake" <eblake@redhat.com>
review comments.

v12:
fix crash caused in qapi_free_BlockdevOptionsGluster
---
 block/gluster.c      | 460 ++++++++++++++++++++++++++++++++++++++++++++-------
 qapi/block-core.json |  64 ++++++-
 2 files changed, 455 insertions(+), 69 deletions(-)

diff --git a/block/gluster.c b/block/gluster.c
index ededda2..2b944e6 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -11,6 +11,16 @@
 #include "block/block_int.h"
 #include "qemu/uri.h"
 
+#define GLUSTER_OPT_FILENAME       "filename"
+#define GLUSTER_OPT_VOLUME         "volume"
+#define GLUSTER_OPT_PATH           "path"
+#define GLUSTER_OPT_HOST           "host"
+#define GLUSTER_OPT_PORT           "port"
+#define GLUSTER_OPT_TRANSPORT      "transport"
+#define GLUSTER_OPT_SERVERS_PATTERN "servers."
+
+#define GLUSTER_DEFAULT_PORT       24007
+
 typedef struct GlusterAIOCB {
     int64_t size;
     int ret;
@@ -29,15 +39,6 @@ typedef struct BDRVGlusterReopenState {
     struct glfs_fd *fd;
 } BDRVGlusterReopenState;
 
-typedef struct GlusterConf {
-    char *host;
-    int port;
-    char *volume;
-    char *path;
-    char *transport;
-} GlusterConf;
-
-
 static QemuOptsList qemu_gluster_create_opts = {
     .name = "qemu-gluster-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_gluster_create_opts.head),
@@ -61,7 +62,7 @@ static QemuOptsList runtime_opts = {
     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
     .desc = {
         {
-            .name = "filename",
+            .name = GLUSTER_OPT_FILENAME,
             .type = QEMU_OPT_STRING,
             .help = "URL to the gluster image",
         },
@@ -69,19 +70,48 @@ static QemuOptsList runtime_opts = {
     },
 };
 
+static QemuOptsList runtime_json_opts = {
+    .name = "gluster_json",
+    .head = QTAILQ_HEAD_INITIALIZER(runtime_json_opts.head),
+    .desc = {
+        {
+            .name = GLUSTER_OPT_VOLUME,
+            .type = QEMU_OPT_STRING,
+            .help = "name of gluster volume where VM image resides",
+        },
+        {
+            .name = GLUSTER_OPT_PATH,
+            .type = QEMU_OPT_STRING,
+            .help = "absolute path to image file in gluster volume",
+        },
+        { /* end of list */ }
+    },
+};
 
-static void qemu_gluster_gconf_free(GlusterConf *gconf)
-{
-    if (gconf) {
-        g_free(gconf->host);
-        g_free(gconf->volume);
-        g_free(gconf->path);
-        g_free(gconf->transport);
-        g_free(gconf);
-    }
-}
+static QemuOptsList runtime_tuple_opts = {
+    .name = "gluster_tuple",
+    .head = QTAILQ_HEAD_INITIALIZER(runtime_tuple_opts.head),
+    .desc = {
+        {
+            .name = GLUSTER_OPT_HOST,
+            .type = QEMU_OPT_STRING,
+            .help = "host address (hostname/ipv4/ipv6 addresses)",
+        },
+        {
+            .name = GLUSTER_OPT_PORT,
+            .type = QEMU_OPT_NUMBER,
+            .help = "port number on which glusterd is listening (default 24007)",
+        },
+        {
+            .name = GLUSTER_OPT_TRANSPORT,
+            .type = QEMU_OPT_STRING,
+            .help = "transport type 'tcp' or 'rdma' (default 'tcp')",
+        },
+        { /* end of list */ }
+    },
+};
 
-static int parse_volume_options(GlusterConf *gconf, char *path)
+static int parse_volume_options(BlockdevOptionsGluster *gconf, char *path)
 {
     char *p, *q;
 
@@ -143,8 +173,11 @@ static int parse_volume_options(GlusterConf *gconf, char *path)
  * file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
  * file=gluster+rdma://1.2.3.4:24007/testvol/a.img
  */
-static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename)
+static int qemu_gluster_parseuri(BlockdevOptionsGluster **pgconf,
+                                 const char *filename)
 {
+    BlockdevOptionsGluster *gconf;
+    GlusterServer *gsconf;
     URI *uri;
     QueryParams *qp = NULL;
     bool is_unix = false;
@@ -155,20 +188,24 @@ static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename)
         return -EINVAL;
     }
 
+    gconf = g_new0(BlockdevOptionsGluster, 1);
+    gsconf = g_new0(GlusterServer, 1);
+
     /* transport */
     if (!uri->scheme || !strcmp(uri->scheme, "gluster")) {
-        gconf->transport = g_strdup("tcp");
+        gsconf->transport = GLUSTER_TRANSPORT_TCP;
     } else if (!strcmp(uri->scheme, "gluster+tcp")) {
-        gconf->transport = g_strdup("tcp");
+        gsconf->transport = GLUSTER_TRANSPORT_TCP;
     } else if (!strcmp(uri->scheme, "gluster+unix")) {
-        gconf->transport = g_strdup("unix");
+        gsconf->transport = GLUSTER_TRANSPORT_UNIX;
         is_unix = true;
     } else if (!strcmp(uri->scheme, "gluster+rdma")) {
-        gconf->transport = g_strdup("rdma");
+        gsconf->transport = GLUSTER_TRANSPORT_RDMA;
     } else {
         ret = -EINVAL;
         goto out;
     }
+    gsconf->has_transport = true;
 
     ret = parse_volume_options(gconf, uri->path);
     if (ret < 0) {
@@ -190,13 +227,27 @@ static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename)
             ret = -EINVAL;
             goto out;
         }
-        gconf->host = g_strdup(qp->p[0].value);
+        gsconf->host = g_strdup(qp->p[0].value);
     } else {
-        gconf->host = g_strdup(uri->server ? uri->server : "localhost");
-        gconf->port = uri->port;
+        gsconf->host = g_strdup(uri->server ? uri->server : "localhost");
+        if (uri->port) {
+            gsconf->port = uri->port;
+        } else {
+            gsconf->port = GLUSTER_DEFAULT_PORT;
+        }
+        gsconf->has_port = true;
     }
 
+    gconf->servers = g_new0(GlusterServerList, 1);
+    gconf->servers->value = gsconf;
+    gconf->servers->next = NULL;
+
+    *pgconf = gconf;
+
 out:
+    if (ret < 0) {
+        qapi_free_BlockdevOptionsGluster(gconf);
+    }
     if (qp) {
         query_params_free(qp);
     }
@@ -204,30 +255,26 @@ out:
     return ret;
 }
 
-static struct glfs *qemu_gluster_init(GlusterConf *gconf, const char *filename,
-                                      Error **errp)
+static struct glfs *qemu_gluster_glfs_init(BlockdevOptionsGluster *gconf,
+                                           Error **errp)
 {
-    struct glfs *glfs = NULL;
+    struct glfs *glfs;
     int ret;
     int old_errno;
-
-    ret = qemu_gluster_parseuri(gconf, filename);
-    if (ret < 0) {
-        error_setg(errp, "Usage: file=gluster[+transport]://[host[:port]]/"
-                         "volume/path[?socket=...]");
-        errno = -ret;
-        goto out;
-    }
+    GlusterServerList *server;
 
     glfs = glfs_new(gconf->volume);
     if (!glfs) {
         goto out;
     }
 
-    ret = glfs_set_volfile_server(glfs, gconf->transport, gconf->host,
-            gconf->port);
-    if (ret < 0) {
-        goto out;
+    for (server = gconf->servers; server != NULL; server = server->next) {
+        ret = glfs_set_volfile_server(glfs,
+                                      GlusterTransport_lookup[server->value->transport],
+                                      server->value->host, server->value->port);
+        if (ret < 0) {
+            goto out;
+        }
     }
 
     /*
@@ -242,10 +289,9 @@ static struct glfs *qemu_gluster_init(GlusterConf *gconf, const char *filename,
     ret = glfs_init(glfs);
     if (ret) {
         error_setg_errno(errp, errno,
-                         "Gluster connection failed for host=%s port=%d "
-                         "volume=%s path=%s transport=%s", gconf->host,
-                         gconf->port, gconf->volume, gconf->path,
-                         gconf->transport);
+                         "Error: Gluster connection failed for given hosts "
+                         "volume:'%s' path:'%s' host1: %s", gconf->volume,
+                         gconf->path, gconf->servers->value->host);
 
         /* glfs_init sometimes doesn't set errno although docs suggest that */
         if (errno == 0)
@@ -264,6 +310,295 @@ out:
     return NULL;
 }
 
+static int parse_transport_option(const char *opt)
+{
+    int i;
+
+    if (!opt) {
+        /* Set tcp as default */
+        return GLUSTER_TRANSPORT_TCP;
+    }
+
+    for (i = 0; i < GLUSTER_TRANSPORT_MAX; i++) {
+        if (!strcmp(opt, GlusterTransport_lookup[i])) {
+            return i;
+        }
+    }
+
+    return -EINVAL;
+}
+
+/*
+*
+*  Basic command line syntax looks like:
+*
+* Pattern I:
+* -drive driver=gluster,
+*        volume=testvol,file.path=/path/a.raw,
+*        servers.0.host=1.2.3.4,
+*       [servers.0.port=24007,]
+*       [servers.0.transport=tcp,]
+*        servers.1.host=5.6.7.8,
+*       [servers.1.port=24008,]
+*       [servers.1.transport=rdma,] ...
+*
+* Pattern II:
+* 'json:{"driver":"qcow2","file":{"driver":"gluster",
+*       "volume":"testvol","path":"/path/a.qcow2",
+*       "servers":[{tuple0},{tuple1}, ...{tupleN}]}}'
+*
+*
+*   driver    => 'gluster' (protocol name)
+*   volume    => name of gluster volume where VM image resides
+*   path      => absolute path of image in gluster volume
+*
+*  {tuple}    => {"host":"1.2.3.4"[,"port":"24007","transport":"tcp"]}
+*
+*   host      => host address (hostname/ipv4/ipv6 addresses)
+*   port      => port number on which glusterd is listening (default 24007)
+*   tranport  => transport type used to connect to gluster management daemon,
+*                 it can be tcp|rdma (default 'tcp')
+*
+*
+* Examples:
+* Pattern I:
+* -drive driver=qcow2,file.driver=gluster,
+*        file.volume=testvol,file.path=/path/a.qcow2,
+*        file.servers.0.host=1.2.3.4,
+*        file.servers.0.port=24007,
+*        file.servers.0.transport=tcp,
+*        file.servers.1.host=5.6.7.8,
+*        file.servers.1.port=24008,
+*        file.servers.1.transport=rdma, ...
+*
+* -drive driver=qcow2,file.driver=gluster,
+*        file.volume=testvol,file.path=/path/a.qcow2,
+*        file.servers.0.host=1.2.3.4,
+*        file.servers.1.host=5.6.7.8, ...
+*
+* -drive driver=qcow2,file.driver=gluster,
+*        file.volume=testvol,file.path=/path/a.qcow2,
+*        file.servers.0.host=1.2.3.4,
+*        file.servers.0.port=24007,
+*        file.servers.1.host=5.6.7.8,
+*        file.servers.1.port=24008, ...
+*
+* -drive driver=qcow2,file.driver=gluster,
+*        file.volume=testvol,file.path=/path/a.qcow2,
+*        file.servers.0.host=1.2.3.4,
+*        file.servers.0.transport=tcp,
+*        file.servers.1.host=5.6.7.8,
+*        file.servers.1.transport=rdma, ...
+*
+* Pattern II:
+* 'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
+*         "path":"/path/a.qcow2","servers":
+*         [{"host":"1.2.3.4","port":"24007","transport":"tcp"},
+*          {"host":"4.5.6.7","port":"24008","transport":"rdma"}, ...]}}'
+*
+* 'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
+*         "path":"/path/a.qcow2","servers":
+*                                    [{"host":"1.2.3.4"},
+*                                     {"host":"4.5.6.7"}, ...]}}'
+*
+*
+* 'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
+*         "path":"/path/a.qcow2","servers":
+*                                  [{"host":"1.2.3.4","port":"24007"},
+*                                   {"host":"4.5.6.7","port":"24008"}, ...]}}'
+*
+*
+* 'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
+*        "path":"/path/a.qcow2","servers":
+*                              [{"host":"1.2.3.4","transport":"tcp"},
+*                               {"host":"4.5.6.7","transport":"rdma"}, ...]}}'
+*
+* Just for better readability pattern II is kept as:
+* json:
+* {
+*    "driver":"qcow2",
+*    "file":{
+*       "driver":"gluster",
+*       "volume":"testvol",
+*       "path":"/path/a.qcow2",
+*       "servers":[
+*          {
+*             "host":"1.2.3.4",
+*             "port":"24007",
+*             "transport":"tcp"
+*          },
+*          {
+*             "host":"5.6.7.8",
+*             "port":"24008",
+*             "transport":"rdma"
+*          }
+*       ]
+*    }
+* }
+*
+*/
+static int qemu_gluster_parsejson(BlockdevOptionsGluster **pgconf,
+                                  QDict *options)
+{
+    QemuOpts *opts;
+    BlockdevOptionsGluster *gconf;
+    GlusterServer *gsconf;
+    GlusterServerList **prev;
+    GlusterServerList *curr;
+    QDict *backing_options = NULL;
+    Error *local_err = NULL;
+    char *str;
+    const char *ptr;
+    size_t num_servers;
+    int i;
+
+    /* create opts info from runtime_json_opts list */
+    opts = qemu_opts_create(&runtime_json_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    gconf = g_new0(BlockdevOptionsGluster, 1);
+    num_servers = qdict_array_entries(options, GLUSTER_OPT_SERVERS_PATTERN);
+    if (num_servers < 1) {
+        error_setg(&local_err, "Error: qemu_gluster: please provide 'servers' "
+                               "option with valid fields in array of tuples");
+        goto out;
+    }
+
+    ptr = qemu_opt_get(opts, GLUSTER_OPT_VOLUME);
+    if (!ptr) {
+        error_setg(&local_err, "Error: qemu_gluster: please provide 'volume' "
+                               "option");
+        goto out;
+    }
+    gconf->volume = g_strdup(ptr);
+
+    ptr = qemu_opt_get(opts, GLUSTER_OPT_PATH);
+    if (!ptr) {
+        error_setg(&local_err, "Error: qemu_gluster: please provide 'path' "
+                               "option");
+        goto out;
+    }
+    gconf->path = g_strdup(ptr);
+
+    qemu_opts_del(opts);
+
+    /* create opts info from runtime_tuple_opts list */
+    str = g_malloc(40);
+    for (i = 0; i < num_servers; i++) {
+        opts = qemu_opts_create(&runtime_tuple_opts, NULL, 0, &error_abort);
+        g_assert(sprintf(str, GLUSTER_OPT_SERVERS_PATTERN"%d.", i) <= 40);
+        qdict_extract_subqdict(options, &backing_options, str);
+        qemu_opts_absorb_qdict(opts, backing_options, &local_err);
+        if (local_err) {
+            goto out;
+        }
+        qdict_del(backing_options, str);
+
+        ptr = qemu_opt_get(opts, GLUSTER_OPT_HOST);
+        if (!ptr) {
+            error_setg(&local_err, "Error: qemu_gluster: servers.{tuple.%d} "
+                                   "requires 'host' option", i);
+            goto out;
+        }
+
+        gsconf = g_new0(GlusterServer, 1);
+
+        gsconf->host = g_strdup(ptr);
+
+        ptr = qemu_opt_get(opts, GLUSTER_OPT_TRANSPORT);
+        /* check whether transport type specified in json command is valid */
+        if (parse_transport_option(ptr) < 0) {
+            error_setg(&local_err, "Error: qemu_gluster: please set 'transport'"
+                                   " type in tuple.%d as tcp or rdma", i);
+            goto out;
+        }
+        /* only if valid transport i.e. either of tcp|rdma is specified */
+        gsconf->transport = parse_transport_option(ptr);
+        gsconf->has_transport = true;
+
+        gsconf->port = qemu_opt_get_number(opts, GLUSTER_OPT_PORT,
+                                                    GLUSTER_DEFAULT_PORT);
+        gsconf->has_port = true;
+
+        if (gconf->servers == NULL) {
+            gconf->servers = g_new0(GlusterServerList, 1);
+            gconf->servers->value = gsconf;
+            curr = gconf->servers;
+        } else {
+            prev = &curr->next;
+            curr = g_new0(GlusterServerList, 1);
+            curr->value = gsconf;
+            *prev = curr;
+        }
+        curr->next = NULL;
+
+        qemu_opts_del(opts);
+    }
+
+    *pgconf = gconf;
+    g_free(str);
+    return 0;
+
+out:
+    error_report_err(local_err);
+    qapi_free_BlockdevOptionsGluster(gconf);
+    qemu_opts_del(opts);
+    if (str) {
+        qdict_del(backing_options, str);
+        g_free(str);
+    }
+    errno = EINVAL;
+    return -errno;
+}
+
+static struct glfs *qemu_gluster_init(BlockdevOptionsGluster **gconf,
+                                      const char *filename,
+                                      QDict *options, Error **errp)
+{
+    int ret;
+
+    if (filename) {
+        ret = qemu_gluster_parseuri(gconf, filename);
+        if (ret < 0) {
+            error_setg(errp, "Usage: file=gluster[+transport]://[host[:port]]/"
+                             "volume/path[?socket=...]");
+            errno = -ret;
+            return NULL;
+        }
+    } else {
+        ret = qemu_gluster_parsejson(gconf, options);
+        if (ret < 0) {
+            error_setg(errp, "Wrong Usage.");
+            error_append_hint(errp,
+                             "Usage1: "
+                             "-drive driver=qcow2,file.driver=gluster,"
+                             "file.volume=testvol,file.path=/path/a.qcow2,"
+                             "file.servers.0.host=1.2.3.4,"
+                             "[file.servers.0.port=24007,]"
+                             "[file.servers.0.transport=tcp,]"
+                             "file.servers.1.host=5.6.7.8,"
+                             "[file.servers.1.port=24008,]"
+                             "[file.servers.1.transport=rdma,] ...");
+            error_append_hint(errp,
+                             "\nUsage2: "
+                             "'json:{\"driver\":\"qcow2\",\"file\":"
+                             "{\"driver\":\"gluster\",\"volume\":\""
+                             "testvol\",\"path\":\"/path/a.qcow2\","
+                             "\"servers\":[{\"host\":\"1.2.3.4\","
+                             "\"port\":\"24007\",\"transport\":\"tcp\"},"
+                             "{\"host\":\"4.5.6.7\",\"port\":\"24007\","
+                             "\"transport\":\"rdma\"}, ...]}}'");
+            errno = -ret;
+            return NULL;
+        }
+    }
+
+    return qemu_gluster_glfs_init(*gconf, errp);
+}
+
 static void qemu_gluster_complete_aio(void *opaque)
 {
     GlusterAIOCB *acb = (GlusterAIOCB *)opaque;
@@ -315,7 +650,7 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
     BDRVGlusterState *s = bs->opaque;
     int open_flags = 0;
     int ret = 0;
-    GlusterConf *gconf = g_new0(GlusterConf, 1);
+    BlockdevOptionsGluster *gconf = NULL;
     QemuOpts *opts;
     Error *local_err = NULL;
     const char *filename;
@@ -329,8 +664,7 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
     }
 
     filename = qemu_opt_get(opts, "filename");
-
-    s->glfs = qemu_gluster_init(gconf, filename, errp);
+    s->glfs = qemu_gluster_init(&gconf, filename, options, errp);
     if (!s->glfs) {
         ret = -errno;
         goto out;
@@ -345,7 +679,7 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
 
 out:
     qemu_opts_del(opts);
-    qemu_gluster_gconf_free(gconf);
+    qapi_free_BlockdevOptionsGluster(gconf);
     if (!ret) {
         return ret;
     }
@@ -363,7 +697,7 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
 {
     int ret = 0;
     BDRVGlusterReopenState *reop_s;
-    GlusterConf *gconf = NULL;
+    BlockdevOptionsGluster *gconf = NULL;
     int open_flags = 0;
 
     assert(state != NULL);
@@ -374,9 +708,7 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
 
     qemu_gluster_parse_flags(state->flags, &open_flags);
 
-    gconf = g_new0(GlusterConf, 1);
-
-    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename, errp);
+    reop_s->glfs = qemu_gluster_init(&gconf, state->bs->filename, NULL, errp);
     if (reop_s->glfs == NULL) {
         ret = -errno;
         goto exit;
@@ -391,7 +723,7 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
 
 exit:
     /* state->opaque will be freed in either the _abort or _commit */
-    qemu_gluster_gconf_free(gconf);
+    qapi_free_BlockdevOptionsGluster(gconf);
     return ret;
 }
 
@@ -500,15 +832,15 @@ static inline int qemu_gluster_zerofill(struct glfs_fd *fd, int64_t offset,
 static int qemu_gluster_create(const char *filename,
                                QemuOpts *opts, Error **errp)
 {
+    BlockdevOptionsGluster *gconf = NULL;
     struct glfs *glfs;
     struct glfs_fd *fd;
     int ret = 0;
     int prealloc = 0;
     int64_t total_size = 0;
     char *tmp = NULL;
-    GlusterConf *gconf = g_new0(GlusterConf, 1);
 
-    glfs = qemu_gluster_init(gconf, filename, errp);
+    glfs = qemu_gluster_init(&gconf, filename, NULL, errp);
     if (!glfs) {
         ret = -errno;
         goto out;
@@ -523,7 +855,7 @@ static int qemu_gluster_create(const char *filename,
     } else if (!strcmp(tmp, "full") && gluster_supports_zerofill()) {
         prealloc = 1;
     } else {
-        error_setg(errp, "Invalid preallocation mode: '%s'"
+        error_setg(errp, "Error: Invalid preallocation mode: '%s'"
                          " or GlusterFS doesn't support zerofill API", tmp);
         ret = -EINVAL;
         goto out;
@@ -548,7 +880,7 @@ static int qemu_gluster_create(const char *filename,
     }
 out:
     g_free(tmp);
-    qemu_gluster_gconf_free(gconf);
+    qapi_free_BlockdevOptionsGluster(gconf);
     if (glfs) {
         glfs_fini(glfs);
     }
@@ -725,7 +1057,7 @@ static BlockDriver bdrv_gluster = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster",
     .instance_size                = sizeof(BDRVGlusterState),
-    .bdrv_needs_filename          = true,
+    .bdrv_needs_filename          = false,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
     .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
@@ -752,7 +1084,7 @@ static BlockDriver bdrv_gluster_tcp = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster+tcp",
     .instance_size                = sizeof(BDRVGlusterState),
-    .bdrv_needs_filename          = true,
+    .bdrv_needs_filename          = false,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
     .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
@@ -806,7 +1138,7 @@ static BlockDriver bdrv_gluster_rdma = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster+rdma",
     .instance_size                = sizeof(BDRVGlusterState),
-    .bdrv_needs_filename          = true,
+    .bdrv_needs_filename          = false,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_reopen_prepare          = qemu_gluster_reopen_prepare,
     .bdrv_reopen_commit           = qemu_gluster_reopen_commit,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index bb2189e..3515d68 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1375,15 +1375,16 @@
 #
 # @host_device, @host_cdrom, @host_floppy: Since 2.1
 # @host_floppy: deprecated since 2.3
+# @gluster: Since 2.5
 #
 # Since: 2.0
 ##
 { 'enum': 'BlockdevDriver',
   'data': [ 'archipelago', 'blkdebug', 'blkverify', 'bochs', 'cloop',
-            'dmg', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
-            'host_floppy', 'http', 'https', 'null-aio', 'null-co', 'parallels',
-            'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp', 'vdi', 'vhdx',
-            'vmdk', 'vpc', 'vvfat' ] }
+            'dmg', 'file', 'ftp', 'ftps', 'gluster', 'host_cdrom',
+            'host_device', 'host_floppy', 'http', 'https', 'null-aio',
+            'null-co', 'parallels', 'qcow', 'qcow2', 'qed', 'quorum', 'raw',
+            'tftp', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
 
 ##
 # @BlockdevOptionsBase
@@ -1794,6 +1795,59 @@
             '*read-pattern': 'QuorumReadPattern' } }
 
 ##
+# @GlusterTransport
+#
+# An enumeration of Gluster transport type
+#
+# @tcp:   TCP   - Transmission Control Protocol
+#
+# @unix:  UNIX  - Unix domain socket
+#
+# @rdma:  RDMA  - Remote direct memory access
+#
+# Since: 2.5
+##
+{ 'enum': 'GlusterTransport', 'data': [ 'tcp', 'unix', 'rdma'] }
+
+##
+# @GlusterServer
+#
+# Gluster tuple set
+#
+# @host:       host address (hostname/ipv4/ipv6 addresses)
+#
+# @port:       #optional port number on which glusterd is listening
+#               (default 24007)
+#
+# @transport:  #optional transport type used to connect to gluster management
+#               daemon (default 'tcp')
+#
+# Since: 2.5
+##
+{ 'struct': 'GlusterServer',
+  'data': { 'host': 'str',
+            '*port': 'int',
+            '*transport': 'GlusterTransport' } }
+
+##
+# @BlockdevOptionsGluster
+#
+# Driver specific block device options for Gluster
+#
+# @volume:   name of gluster volume where VM image resides
+#
+# @path:     absolute path to image file in gluster volume
+#
+# @servers:  one or more gluster server descriptions (host, port, and transport)
+#
+# Since: 2.5
+##
+{ 'struct': 'BlockdevOptionsGluster',
+  'data': { 'volume': 'str',
+            'path': 'str',
+            'servers': [ 'GlusterServer' ] } }
+
+##
 # @BlockdevOptions
 #
 # Options for creating a block device.
@@ -1813,7 +1867,7 @@
       'file':       'BlockdevOptionsFile',
       'ftp':        'BlockdevOptionsFile',
       'ftps':       'BlockdevOptionsFile',
-# TODO gluster: Wait for structured options
+      'gluster':    'BlockdevOptionsGluster',
       'host_cdrom': 'BlockdevOptionsFile',
       'host_device':'BlockdevOptionsFile',
       'host_floppy':'BlockdevOptionsFile',
-- 
2.1.0

Re: [Qemu-devel] [PATCH v12 3/3] block/gluster: add support for multiple gluster servers

[Jeff Cody]

Hi,

For future revisions, could you send all patches in the series (even
if unchanged)?  It makes it much easier to know which patches are the
latest.

Also, if you can rebase each release on the qemu master branch, that
would be preferred (or on a submaintainers tree, just mention that in
the cover letter / patch).  This didn't apply cleanly to qemu master
as-is, which is why I mentioned it.

Thanks, and some more items below:

On Mon, Nov 09, 2015 at 03:32:13PM +0530, Prasanna Kumar Kalever wrote:
> This patch adds a way to specify multiple volfile servers to the gluster
> block backend of QEMU with tcp|rdma transport types and their port numbers.
> 
> Problem:
> 
> Currently VM Image on gluster volume is specified like this:
> 
> file=gluster[+tcp]://host[:port]/testvol/a.img
> 
> Assuming we have three hosts in trusted pool with replica 3 volume
> in action and unfortunately host (mentioned in the command above) went down
> for some reason, since the volume is replica 3 we now have other 2 hosts
> active from which we can boot the VM.
> 
> But currently there is no mechanism to pass the other 2 gluster host
> addresses to qemu.
> 
> Solution:
> 
> New way of specifying VM Image on gluster volume with volfile servers:
> (We still support old syntax to maintain backward compatibility)
>

[...]

> 
> This patch depends on a recent fix in libgfapi raised as part of this work:
> http://review.gluster.org/#/c/12114/
>

What happens if the user attempts to use this functionality, but does
not have the latest version of libfgapi?  How gracefully do we fail?

> Credits: Sincere thanks to Kevin Wolf <kwolf@redhat.com> and
> "Deepak C Shetty" <deepakcs@redhat.com> for inputs and all their support
> 
> Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
> ---

[...]

> ---
>  block/gluster.c      | 460 ++++++++++++++++++++++++++++++++++++++++++++-------
>  qapi/block-core.json |  64 ++++++-
>  2 files changed, 455 insertions(+), 69 deletions(-)
> 
> diff --git a/block/gluster.c b/block/gluster.c
> index ededda2..2b944e6 100644
> --- a/block/gluster.c
> +++ b/block/gluster.c
> @@ -11,6 +11,16 @@
>  #include "block/block_int.h"
>  #include "qemu/uri.h"
>

[...]

> +static int qemu_gluster_parsejson(BlockdevOptionsGluster **pgconf,
> +                                  QDict *options)
> +{
> +    QemuOpts *opts;
> +    BlockdevOptionsGluster *gconf;

This (gconf) needs to be initialized to NULL, because 'out' is
reachable before you allocated gconf.

> +    GlusterServer *gsconf;
> +    GlusterServerList **prev;
> +    GlusterServerList *curr;

This (curr) needs to be initialized to NULL (explained below).

> +    QDict *backing_options = NULL;
> +    Error *local_err = NULL;
> +    char *str;

This (str) needs to be initialized to NULL, because 'out' is reachable
before you allocated 'str'.

> +    const char *ptr;
> +    size_t num_servers;
> +    int i;
> +
> +    /* create opts info from runtime_json_opts list */
> +    opts = qemu_opts_create(&runtime_json_opts, NULL, 0, &error_abort);
> +    qemu_opts_absorb_qdict(opts, options, &local_err);
> +    if (local_err) {
> +        goto out;
> +    }
> +
> +    gconf = g_new0(BlockdevOptionsGluster, 1);
> +    num_servers = qdict_array_entries(options, GLUSTER_OPT_SERVERS_PATTERN);
> +    if (num_servers < 1) {
> +        error_setg(&local_err, "Error: qemu_gluster: please provide 'servers' "
> +                               "option with valid fields in array of tuples");
> +        goto out;
> +    }

Is there a maximum number of servers that can be specified?

> +
> +    ptr = qemu_opt_get(opts, GLUSTER_OPT_VOLUME);
> +    if (!ptr) {
> +        error_setg(&local_err, "Error: qemu_gluster: please provide 'volume' "
> +                               "option");
> +        goto out;
> +    }
> +    gconf->volume = g_strdup(ptr);
> +
> +    ptr = qemu_opt_get(opts, GLUSTER_OPT_PATH);
> +    if (!ptr) {
> +        error_setg(&local_err, "Error: qemu_gluster: please provide 'path' "
> +                               "option");
> +        goto out;
> +    }
> +    gconf->path = g_strdup(ptr);
> +
> +    qemu_opts_del(opts);
> +
> +    /* create opts info from runtime_tuple_opts list */
> +    str = g_malloc(40);
> +    for (i = 0; i < num_servers; i++) {
> +        opts = qemu_opts_create(&runtime_tuple_opts, NULL, 0, &error_abort);
> +        g_assert(sprintf(str, GLUSTER_OPT_SERVERS_PATTERN"%d.", i) <= 40);

Is 40 characters just the assumed maximum string length?  I know that
GLUSTER_OPT_SERVERS_PATTERN is pretty short, but it concerns me seeing
40 characters hardcoded in the malloc and check here.   It would be
better to use the maximum string size of the resulting string, for the
known maximum number of servers.

Also, using g_assert() here doesn't stop overwriting 'str', it just
alerts that it has happened.  We should use snprintf() instead (and we
could probably return an error rather than abort).


> +        qdict_extract_subqdict(options, &backing_options, str);
> +        qemu_opts_absorb_qdict(opts, backing_options, &local_err);
> +        if (local_err) {
> +            goto out;
> +        }
> +        qdict_del(backing_options, str);
> +
> +        ptr = qemu_opt_get(opts, GLUSTER_OPT_HOST);
> +        if (!ptr) {
> +            error_setg(&local_err, "Error: qemu_gluster: servers.{tuple.%d} "
> +                                   "requires 'host' option", i);
> +            goto out;
> +        }
> +
> +        gsconf = g_new0(GlusterServer, 1);
> +
> +        gsconf->host = g_strdup(ptr);
> +
> +        ptr = qemu_opt_get(opts, GLUSTER_OPT_TRANSPORT);
> +        /* check whether transport type specified in json command is valid */
> +        if (parse_transport_option(ptr) < 0) {
> +            error_setg(&local_err, "Error: qemu_gluster: please set 'transport'"
> +                                   " type in tuple.%d as tcp or rdma", i);
> +            goto out;
> +        }
> +        /* only if valid transport i.e. either of tcp|rdma is specified */
> +        gsconf->transport = parse_transport_option(ptr);
> +        gsconf->has_transport = true;
> +
> +        gsconf->port = qemu_opt_get_number(opts, GLUSTER_OPT_PORT,
> +                                                    GLUSTER_DEFAULT_PORT);
> +        gsconf->has_port = true;
> +
> +        if (gconf->servers == NULL) {
> +            gconf->servers = g_new0(GlusterServerList, 1);
> +            gconf->servers->value = gsconf;
> +            curr = gconf->servers;
> +        } else {
> +            prev = &curr->next;

curr needs to be initialized to NULL, because the compiler has no way
of knowing that the gconf = g_new0() above means gconf->servers will
always be NULL the first iteration.  As-is, this causes a compile
error (ok, warning, but we use -werror).

> +            curr = g_new0(GlusterServerList, 1);
> +            curr->value = gsconf;
> +            *prev = curr;
> +        }
> +        curr->next = NULL;
> +
> +        qemu_opts_del(opts);
> +    }
> +
> +    *pgconf = gconf;
> +    g_free(str);
> +    return 0;
> +
> +out:
> +    error_report_err(local_err);
> +    qapi_free_BlockdevOptionsGluster(gconf);
> +    qemu_opts_del(opts);
> +    if (str) {
> +        qdict_del(backing_options, str);
> +        g_free(str);
> +    }
> +    errno = EINVAL;
> +    return -errno;
> +}
> +

[...]

-Jeff