On 09/18/12 00:08, Eric Blake wrote:
The wait loop logic borrows heavily from blockcommit.
Maybe a little too sparse on the commit message, but the man page addition makes it up.
* tools/virsh-domain.c (cmdBlockCommit): New function. * tools/virsh.pod (blockcommit): Document it. --- tools/virsh-domain.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++- tools/virsh.pod | 30 ++++++++++ 2 files changed, 182 insertions(+), 1 deletion(-) diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index b6de9a8..aa23011 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -1260,6 +1272,144 @@ static void vshCatchInt(int sig ATTRIBUTE_UNUSED, } /* + * "blockcommit" command + */ +static const vshCmdInfo info_block_commit[] = { + {"help", N_("Start a block commit operation.")}, + {"desc", N_("Commit changes from a snapshot down to its backing image.")}, + {NULL, NULL} +}; + +static const vshCmdOptDef opts_block_commit[] = { + {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, + {"path", VSH_OT_DATA, VSH_OFLAG_REQ, N_("fully-qualified path of disk")},
The API says you can use "vda" and similar, is that considered fully-qualified? / this question was answered below /
+ {"bandwidth", VSH_OT_DATA, VSH_OFLAG_NONE, N_("bandwidth limit in MiB/s")},
Megabits look like a reasonable granularity to limit this. Well maybe apart from testing purposes where somebody would like to do it really slow to be able to poke around.
+ {"base", VSH_OT_DATA, VSH_OFLAG_NONE, + N_("path of base file to commit into (default bottom of chain)")}, + {"shallow", VSH_OT_BOOL, 0, N_("use backing file of top as base")}, + {"top", VSH_OT_DATA, VSH_OFLAG_NONE, + N_("path of top file to commit from (default top of chain)")}, + {"delete", VSH_OT_BOOL, 0, + N_("delete files that were successfully committed")}, + {"wait", VSH_OT_BOOL, 0, N_("wait for job to complete")}, + {"verbose", VSH_OT_BOOL, 0, N_("with --wait, display the progress")}, + {"timeout", VSH_OT_INT, VSH_OFLAG_NONE, + N_("with --wait, abort if copy exceeds timeout (in seconds)")}, + {NULL, 0, 0, NULL} +}; + +static bool +cmdBlockCommit(vshControl *ctl, const vshCmd *cmd) +{ + virDomainPtr dom = NULL; + bool ret = false; + bool blocking = vshCommandOptBool(cmd, "wait"); + bool verbose = vshCommandOptBool(cmd, "verbose"); + int timeout = 0; + struct sigaction sig_action; + struct sigaction old_sig_action; + sigset_t sigmask; + struct timeval start; + struct timeval curr; + const char *path = NULL; + bool quit = false; + int abort_flags = 0; + + if (blocking) { + if (vshCommandOptInt(cmd, "timeout", &timeout) > 0) { + if (timeout < 1) { + vshError(ctl, "%s", _("invalid timeout")); + return false; + } + + /* Ensure that we can multiply by 1000 without overflowing. */ + if (timeout > INT_MAX / 1000) { + vshError(ctl, "%s", _("timeout is too big")); + return false; + } + } + if (vshCommandOptString(cmd, "path", &path) < 0) + return false; + if (vshCommandOptBool(cmd, "async")) + abort_flags |= VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC; + + sigemptyset(&sigmask); + sigaddset(&sigmask, SIGINT); + + intCaught = 0; + sig_action.sa_sigaction = vshCatchInt; + sig_action.sa_flags = SA_SIGINFO; + sigemptyset(&sig_action.sa_mask); + sigaction(SIGINT, &sig_action, &old_sig_action); + + GETTIMEOFDAY(&start); + } else if (verbose || vshCommandOptBool(cmd, "timeout") || + vshCommandOptBool(cmd, "async")) { + vshError(ctl, "%s", _("blocking control options require --wait"));
This error message isn't 100% clear on the first read. What about: "--verbose and --timeout require --wait" ?
+ return false; + } + + if (blockJobImpl(ctl, cmd, NULL, VSH_CMD_BLOCK_JOB_COMMIT, &dom) < 0) + goto cleanup; + + if (!blocking) { + vshPrint(ctl, "%s", _("Block Commit started")); + ret = true; + goto cleanup; + } + + while (blocking) { + virDomainBlockJobInfo info; + int result = virDomainGetBlockJobInfo(dom, path, &info, 0); + + if (result < 0) { + vshError(ctl, _("failed to query job for disk %s"), path); + goto cleanup; + } + if (result == 0) + break; + + if (verbose) + print_job_progress(_("Block Commit"), + info.end - info.cur, info.end); + + GETTIMEOFDAY(&curr); + if (intCaught || (timeout && + (((int)(curr.tv_sec - start.tv_sec) * 1000 + + (int)(curr.tv_usec - start.tv_usec) / 1000) > + timeout * 1000))) {
Wouldn't it be better to multiply timeout by 1000 at the beginning and not bother re-doing it on every iteration?
+ vshDebug(ctl, VSH_ERR_DEBUG, + intCaught ? "interrupted" : "timeout"); + intCaught = 0; + timeout = 0; + quit = true; + if (virDomainBlockJobAbort(dom, path, abort_flags) < 0) { + vshError(ctl, _("failed to abort job for disk %s"), path); + goto cleanup; + } + if (abort_flags & VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC) + break; + } else { + usleep(500 * 1000); + } + } + + if (verbose && !quit) { + /* printf [100 %] */ + print_job_progress(_("Block Commit"), 0, 1); + } + vshPrint(ctl, "\n%s", quit ? _("Commit aborted") : _("Commit complete"));
Meh a ternary ... but saves lines.
+ + ret = true; +cleanup: + if (dom) + virDomainFree(dom); + if (blocking) + sigaction(SIGINT, &old_sig_action, NULL); + return ret; +} + +/* * "blockcopy" command */ static const vshCmdInfo info_block_copy[] = { @@ -8112,6 +8262,7 @@ const vshCmdDef domManagementCmds[] = { {"autostart", cmdAutostart, opts_autostart, info_autostart, 0}, {"blkdeviotune", cmdBlkdeviotune, opts_blkdeviotune, info_blkdeviotune, 0}, {"blkiotune", cmdBlkiotune, opts_blkiotune, info_blkiotune, 0}, + {"blockcommit", cmdBlockCommit, opts_block_commit, info_block_commit, 0}, {"blockcopy", cmdBlockCopy, opts_block_copy, info_block_copy, 0}, {"blockjob", cmdBlockJob, opts_block_job, info_block_job, 0}, {"blockpull", cmdBlockPull, opts_block_pull, info_block_pull, 0}, diff --git a/tools/virsh.pod b/tools/virsh.pod index bb135da..4a79e12 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -694,6 +694,36 @@ currently in use by a running domain. Other contexts that require a MAC address of virtual interface (such as I<detach-interface> or I<domif-setlink>) will accept the MAC address printed by this command. +=item B<blockcommit> I<domain> I<path> [I<bandwidth>] +{[I<base>] | [I<--shallow>]} [I<top>] [I<--delete>] +[I<--wait> [I<--verbose>] [I<--timeout> B<seconds>]] + +Reduce the length of a backing image chain, by committing changes at the +top of the chain (snapshot or delta files) into backing images. By +default, this command attempts to flatten the entire chain. If I<base> +and/or I<top> are specified as files within the backing chain, then the +operation is constrained to committing just that portion of the chain; +I<--shallow> can be used instead of I<base> to specify the immediate +backing file of the resulting top image to be committed. The files +being committed are rendered invalid, possibly as soon as the operation +starts; using the I<--delete> flag will remove these files at the successful +completion of the commit operation. + +By default, this command returns as soon as possible, and data for +the entire disk is committed in the background; the progress of the +operation can be checked with B<blockjob>. However, if I<--wait> is +specified, then this command will block until the operation completes, +or cancel the operation if the optional I<timeout> in seconds elapses +or SIGINT is sent (usually with C<Ctrl-C>). Using I<--verbose> along +with I<--wait> will produce periodic status updates. + +I<path> specifies fully-qualified path of the disk; it corresponds +to a unique target name (<target dev='name'/>) or source file (<source +file='name'/>) for one of the disk devices attached to I<domain> (see
Okay, this answers my question from the beginning.
+also B<domblklist> for listing these names). +I<bandwidth> specifies copying bandwidth limit in MiB/s, although for +qemu, it may be non-zero only for an online domain. + =item B<blockcopy> I<domain> I<path> I<dest> [I<bandwidth>] [I<--shallow>] [I<--reuse-external>] [I<--raw>] [I<--wait> [I<--verbose] [{I<--pivot> | I<--finish>}] [I<--timeout> B<seconds>] [I<--async>]]
Your docs are always great. ACK Peter -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list