| Message ID | 1484884080-28836-3-git-send-email-zhang.zhanghailiang@huawei.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Jan 20, 2017 at 11:47:56AM +0800, zhanghailiang wrote: > @@ -119,12 +136,31 @@ static int replication_open(BlockDriverState *bs, QDict *options, > "The option mode's value should be primary or secondary"); > goto fail; > } > + s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK, > + false); > + if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) { > + shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID); > + if (!shared_disk_id) { > + error_setg(&local_err, "Missing shared disk blk option"); > + goto fail; > + } > + s->shared_disk_id = g_strdup(shared_disk_id); > + blk = blk_by_name(s->shared_disk_id); > + if (!blk) { > + error_setg(&local_err, "There is no %s block", s->shared_disk_id); > + goto fail; > + } > + /* We can't access root member of BlockBackend directly */ > + tmp_bs = blk_bs(blk); > + s->primary_disk = QLIST_FIRST(&tmp_bs->parents); Why is this necessary? We already have the BlockBackend for the primary disk. I'm not sure why the BdrvChild is needed. Stefan
On 2017/2/28 1:10, Stefan Hajnoczi wrote: > On Fri, Jan 20, 2017 at 11:47:56AM +0800, zhanghailiang wrote: >> @@ -119,12 +136,31 @@ static int replication_open(BlockDriverState *bs, QDict *options, >> "The option mode's value should be primary or secondary"); >> goto fail; >> } >> + s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK, >> + false); >> + if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) { >> + shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID); >> + if (!shared_disk_id) { >> + error_setg(&local_err, "Missing shared disk blk option"); >> + goto fail; >> + } >> + s->shared_disk_id = g_strdup(shared_disk_id); >> + blk = blk_by_name(s->shared_disk_id); >> + if (!blk) { >> + error_setg(&local_err, "There is no %s block", s->shared_disk_id); >> + goto fail; >> + } >> + /* We can't access root member of BlockBackend directly */ >> + tmp_bs = blk_bs(blk); >> + s->primary_disk = QLIST_FIRST(&tmp_bs->parents); > > Why is this necessary? > > We already have the BlockBackend for the primary disk. I'm not sure why > the BdrvChild is needed. > Er, the helper backup_job_create() needs the BlockDriverState for the primary disk, besides, we want to make it same with 'secondary_disk' in struct BDRVReplicationState. Thanks. Hailiang > Stefan >
On Wed, Mar 01, 2017 at 11:53:14AM +0800, Hailiang Zhang wrote: > On 2017/2/28 1:10, Stefan Hajnoczi wrote: > > On Fri, Jan 20, 2017 at 11:47:56AM +0800, zhanghailiang wrote: > > > @@ -119,12 +136,31 @@ static int replication_open(BlockDriverState *bs, QDict *options, > > > "The option mode's value should be primary or secondary"); > > > goto fail; > > > } > > > + s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK, > > > + false); > > > + if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) { > > > + shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID); > > > + if (!shared_disk_id) { > > > + error_setg(&local_err, "Missing shared disk blk option"); > > > + goto fail; > > > + } > > > + s->shared_disk_id = g_strdup(shared_disk_id); > > > + blk = blk_by_name(s->shared_disk_id); > > > + if (!blk) { > > > + error_setg(&local_err, "There is no %s block", s->shared_disk_id); > > > + goto fail; > > > + } > > > + /* We can't access root member of BlockBackend directly */ > > > + tmp_bs = blk_bs(blk); > > > + s->primary_disk = QLIST_FIRST(&tmp_bs->parents); > > > > Why is this necessary? > > > > We already have the BlockBackend for the primary disk. I'm not sure why > > the BdrvChild is needed. > > > > Er, the helper backup_job_create() needs the BlockDriverState for the primary disk, You can get the BDS any time using blk_bs(). > besides, we want to make it same with 'secondary_disk' in struct BDRVReplicationState. Block drivers are allowed to access BDS->parents so it's not necessarily a problem that the code does this. But it's rare and usually means there is a non-standard relationship between BDS nodes. It wasn't obvious from the code why you are going through the trouble of getting a BdrvChild instead of using the BlockBackend (the normal way of accessing a drive). Perhaps a comment would help: /* We have a BlockBackend for the primary disk but use BdrvChild for * consistency - active_disk, secondary_disk, etc are also BdrvChild. */ Stefan
diff --git a/block/replication.c b/block/replication.c index 729dd12..b96a3e5 100644 --- a/block/replication.c +++ b/block/replication.c @@ -25,9 +25,12 @@ typedef struct BDRVReplicationState { ReplicationMode mode; int replication_state; + bool is_shared_disk; + char *shared_disk_id; BdrvChild *active_disk; BdrvChild *hidden_disk; BdrvChild *secondary_disk; + BdrvChild *primary_disk; char *top_id; ReplicationState *rs; Error *blocker; @@ -53,6 +56,9 @@ static void replication_stop(ReplicationState *rs, bool failover, #define REPLICATION_MODE "mode" #define REPLICATION_TOP_ID "top-id" +#define REPLICATION_SHARED_DISK "shared-disk" +#define REPLICATION_SHARED_DISK_ID "shared-disk-id" + static QemuOptsList replication_runtime_opts = { .name = "replication", .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head), @@ -65,6 +71,14 @@ static QemuOptsList replication_runtime_opts = { .name = REPLICATION_TOP_ID, .type = QEMU_OPT_STRING, }, + { + .name = REPLICATION_SHARED_DISK_ID, + .type = QEMU_OPT_STRING, + }, + { + .name = REPLICATION_SHARED_DISK, + .type = QEMU_OPT_BOOL, + }, { /* end of list */ } }, }; @@ -85,6 +99,9 @@ static int replication_open(BlockDriverState *bs, QDict *options, QemuOpts *opts = NULL; const char *mode; const char *top_id; + const char *shared_disk_id; + BlockBackend *blk; + BlockDriverState *tmp_bs; ret = -EINVAL; opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort); @@ -119,12 +136,31 @@ static int replication_open(BlockDriverState *bs, QDict *options, "The option mode's value should be primary or secondary"); goto fail; } + s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK, + false); + if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) { + shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID); + if (!shared_disk_id) { + error_setg(&local_err, "Missing shared disk blk option"); + goto fail; + } + s->shared_disk_id = g_strdup(shared_disk_id); + blk = blk_by_name(s->shared_disk_id); + if (!blk) { + error_setg(&local_err, "There is no %s block", s->shared_disk_id); + goto fail; + } + /* We can't access root member of BlockBackend directly */ + tmp_bs = blk_bs(blk); + s->primary_disk = QLIST_FIRST(&tmp_bs->parents); + } s->rs = replication_new(bs, &replication_ops); ret = 0; fail: + g_free(s->shared_disk_id); qemu_opts_del(opts); error_propagate(errp, local_err); @@ -135,6 +171,7 @@ static void replication_close(BlockDriverState *bs) { BDRVReplicationState *s = bs->opaque; + g_free(s->shared_disk_id); if (s->replication_state == BLOCK_REPLICATION_RUNNING) { replication_stop(s->rs, false, NULL); } diff --git a/qapi/block-core.json b/qapi/block-core.json index 1b3e6eb..e9fecda 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2624,12 +2624,20 @@ # node who owns the replication node chain. Must not be given in # primary mode. # +# @shared-disk-id: #optional id of shared disk while is replication mode, +# if @shared-disk is true, this option is required (Since: 2.9) +# +# @shared-disk: #optional (The default is false) to indicate whether or not +# a disk is shared by primary VM and secondary VM. (Since: 2.9) +# # Since: 2.8 ## { 'struct': 'BlockdevOptionsReplication', 'base': 'BlockdevOptionsGenericFormat', 'data': { 'mode': 'ReplicationMode', - '*top-id': 'str' } } + '*top-id': 'str', + '*shared-disk-id': 'str', + '*shared-disk': 'bool' } } ## # @NFSTransport: