Re: [libvirt] [PATCHv2] LXC: Fix handling of RAM filesystem size units

Since 76b644c when the support for RAM filesystems was introduced, libvirt accepted the following XML: <source usage='1024' unit='KiB'/> This was parsed correctly and internally stored in bytes, but it was formatted as (with an extra 's'): <source usage='1024' units='KiB'/> When read again, this was treated as if the units were missing, meaning libvirt was unable to parse its own XML correctly. The usage attribute was documented as being in KiB, but it was not scaled if the unit was missing. Transient domains still worked, because this was balanced by an extra 'k' in the mount options. This patch: Outputs the units via the 'unit' attribute (fixing persistent domains), but accepts both 'unit' and 'units' (for compatibility with older libvirt and libvirt-sandbox). Removes the extra 'k' from the tmpfs mount options, which is needed because now we parse our own XML correctly. Changes the default unit to KiB to match documentation, fixing: https://bugzilla.redhat.com/show_bug.cgi?id=1015689 --- v1: https://www.redhat.com/archives/libvir-list/2013-October/msg00361.html v2: keeps the output unit KiB changes the default input unit to KiB accepts 'units' as well as 'unit' in input XML docs/formatdomain.html.in | 6 ++-- docs/schemas/domaincommon.rng | 5 ++++ src/conf/domain_conf.c | 12 ++++++-- src/lxc/lxc_container.c | 2 +- tests/domainschematest | 2 +- tests/lxcxml2xmldata/lxc-filesystem-ram.xml | 41 ++++++++++++++++++++++++++ tests/lxcxml2xmloutdata/lxc-filesystem-ram.xml | 41 ++++++++++++++++++++++++++ tests/lxcxml2xmltest.c | 1 + 8 files changed, 103 insertions(+), 7 deletions(-) create mode 100644 tests/lxcxml2xmldata/lxc-filesystem-ram.xml create mode 100644 tests/lxcxml2xmloutdata/lxc-filesystem-ram.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 3689399..dfd11bf 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2213,7 +2213,8 @@ <dd> An in-memory filesystem, using memory from the host OS. The source element has a single attribute <code>usage</code> - which gives the memory usage limit in kibibytes. Only used + which gives the memory usage limit in KiB, unless units + are specified by the <code>unit</code> attribute. Only used by LXC driver. <span class="since"> (since 0.9.13)</span></dd> <dt><code>type='bind'</code></dt> @@ -2279,7 +2280,8 @@ <code>name</code> attribute must be used with <code>type='template'</code>, and the <code>dir</code> attribute must be used with <code>type='mount'</code>. The <code>usage</code> attribute - is used with <code>type='ram'</code> to set the memory limit in KB. + is used with <code>type='ram'</code> to set the memory limit KiB, unless + units are specified by the <code>unit</code> attribute. </dd> <dt><code>target</code></dt> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 5c5301d..582d4c3 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -1736,6 +1736,11 @@ <ref name='unit'/> </attribute> </optional> + <optional> + <attribute name='units'> + <ref name='unit'/> + </attribute> + </optional> <empty/> </element> </interleave> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 0d63845..0870047 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -5917,6 +5917,7 @@ virDomainFSDefParseXML(xmlNodePtr node, char *wrpolicy = NULL; char *usage = NULL; char *unit = NULL; + char *units = NULL; ctxt->node = node; @@ -5973,6 +5974,7 @@ virDomainFSDefParseXML(xmlNodePtr node, else if (def->type == VIR_DOMAIN_FS_TYPE_RAM) { usage = virXMLPropString(cur, "usage"); unit = virXMLPropString(cur, "unit"); + units = virXMLPropString(cur, "units");

} } else if (!target && xmlStrEqual(cur->name, BAD_CAST "target")) { @@ -6042,8 +6044,11 @@ virDomainFSDefParseXML(xmlNodePtr node, usage); goto error; } - if (unit && - virScaleInteger(&def->usage, unit, + /* Older libvirt only parsed 'unit' here, despite + * printing it in the 'units' attribute. + * + * The default was bytes when 'unit' wasn't present */ + if (virScaleInteger(&def->usage, units ? units : unit, 1024, ULLONG_MAX) < 0) goto error; } @@ -6066,6 +6071,7 @@ cleanup: VIR_FREE(wrpolicy); VIR_FREE(usage); VIR_FREE(unit); + VIR_FREE(units); VIR_FREE(format); return def; @@ -14764,7 +14770,7 @@ virDomainFSDefFormat(virBufferPtr buf, break; case VIR_DOMAIN_FS_TYPE_RAM: - virBufferAsprintf(buf, " <source usage='%lld' units='KiB'/>\n", + virBufferAsprintf(buf, " <source usage='%lld' unit='KiB'/>\n", def->usage / 1024); break;