[libvirt] [PATCH 4/4] virsh: Expose new virDomainFSTrim API

[Daniel P. Berrange]

On Wed, Nov 28, 2012 at 11:56:23AM +0100, Peter Krempa wrote:
> On 11/20/12 19:47, Michal Privoznik wrote:
> >under domfstrim command. Since API doesn't support all
> >parameters (some must be NULL or zero), don't expose
> >these in virsh neither.
> >---
> >  tools/virsh-domain.c |   40 ++++++++++++++++++++++++++++++++++++++++
> >  tools/virsh.pod      |   12 ++++++++++++
> >  2 files changed, 52 insertions(+), 0 deletions(-)
> >
> >diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
> >index cc47383..4ea08f4 100644
> >--- a/tools/virsh-domain.c
> >+++ b/tools/virsh-domain.c
> >@@ -8300,6 +8300,45 @@ cleanup:
> >      return ret;
> >  }
> >
> >+static const vshCmdInfo info_domfstrim[] = {
> >+    {"help", N_("Invoke fstrim on domain's mounted filesystems.")},
> >+    {"desc", N_("Invoke fstrim on domain's mounted filesystems.")},
> >+    {NULL, NULL}
> >+};
> >+
> >+static const vshCmdOptDef opts_domfstrim[] = {
> >+    {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
> >+    {"minimum", VSH_OT_INT, 0, N_("Just a hint to ignore contiguous "
> >+                                  "free ranges smaller than this (Bytes)")},
> 
> Wouldn't it make sense to expose the mount point argument right now?
> I know it's not implemented yet, but when somebody does implement
> that we will need to change this later.
> 
> >+    {NULL, 0, 0, NULL}
> >+};
> >+static bool
> >+cmdDomFSTrim(vshControl *ctl, const vshCmd *cmd)
> >+{
> >+    virDomainPtr dom = NULL;
> >+    bool ret = false;
> >+    unsigned long long minimum = 0;
> >+    unsigned int flags = 0;
> >+
> >+    if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
> >+        goto cleanup;
> >+
> >+    if (vshCommandOptULongLong(cmd, "minimum", &minimum) < 0) {
> >+        vshError(ctl, _("Unable to parse integer parameter"));
> 
> As you know what's the name of the parameter print it in the error
> message so the user is not left guessing where the error is.
> 
> >+        goto cleanup;
> >+    }
> >+
> >+    if (virDomainFSTrim(dom, NULL, minimum, flags) < 0) {
> >+        vshError(ctl, _("Unable to invoke fstrim"));
> >+        goto cleanup;
> >+    }
> >+
> >+    ret = true;
> >+
> >+cleanup:
> >+    return ret;
> >+}
> >+
> >  const vshCmdDef domManagementCmds[] = {
> >      {"attach-device", cmdAttachDevice, opts_attach_device,
> >       info_attach_device, 0},
> >@@ -8332,6 +8371,7 @@ const vshCmdDef domManagementCmds[] = {
> >      {"detach-interface", cmdDetachInterface, opts_detach_interface,
> >       info_detach_interface, 0},
> >      {"domdisplay", cmdDomDisplay, opts_domdisplay, info_domdisplay, 0},
> >+    {"domfstrim", cmdDomFSTrim, opts_domfstrim, info_domfstrim, 0},
> >      {"domhostname", cmdDomHostname, opts_domhostname, info_domhostname, 0},
> >      {"domid", cmdDomid, opts_domid, info_domid, 0},
> >      {"domif-setlink", cmdDomIfSetLink, opts_domif_setlink, info_domif_setlink, 0},
> >diff --git a/tools/virsh.pod b/tools/virsh.pod
> >index 29be39e..c3fdcb7 100644
> >--- a/tools/virsh.pod
> >+++ b/tools/virsh.pod
> >@@ -878,6 +878,18 @@ Output a URI which can be used to connect to the graphical display of the
> >  domain via VNC, SPICE or RDP. If I<--include-password> is specified, the
> >  SPICE channel password will be included in the URI.
> >
> >+=item B<domfstrim> I<domain> [I<--minimum> B<bytes>]
> >+
> >+Issue a fstrim command on all mounted filesystems within a running
> >+domain. It discards blocks which are not in use by the filesystem.
> >+If I<--minimum> B<bytes> is specified, it tells guest kernel length
> >+of contiguous free range. Smaller than this may be ignored (this is
> >+a hint and the guest may not respect it). By increasing this value,
> >+the fstrim operation will complete more quickly for filesystems
> >+with badly fragmented free space, although not all blocks will
> >+be discarded.  The default value is zero, meaning "discard
> >+every free block".
> >+
> >  =item B<domhostname> I<domain>
> >
> >  Returns the hostname of a domain, if the hypervisor makes it available.
> >
> 
> I'd rather see this with the ability to specify mountpoint to the
> api even if it still isn't supported.

Agreed, we should not cripple virsh to suit a particular libvirtd
feature set, because you have to bear in mind that we have an RPC
system that allows an old virsh to talk to a new libvirtd.


Daniel
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