[libvirt] [PATCH v3] virsh: Add option to undefine storage with domains

Add an option for virsh undefine command, to remove associated storage volumes while undefining a domain. This patch alows the user to remove associated (libvirt managed ) storage volumes while undefining a domain. The new option --storage for the undefine command takes a string argument that consists of comma separated list of target or source path of volumes to be undefined. Volumes are removed after the domain has been successfuly undefined, If a volume is not part of a storage pool, the user is warned to remove the volume in question himself. Option --wipe-storage may be specified along with this, that ensures the image is wiped before removing. Option --remove-all-storage enables the user to remove all storage. The name is chosen long as the users shoudl be aware what they're about to do. --- Changes to v2 based on reveiw by Eric: ( http://www.redhat.com/archives/libvir-list/2011-September/msg00481.html ) - First undefine the domain, then undefine volumes - Add option to remove all volumes - Fix typos and strange wordings - Change retur value to failure if some operations on volumes fail. tools/virsh.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/virsh.pod | 18 +++++++ 2 files changed, 161 insertions(+), 0 deletions(-) diff --git a/tools/virsh.c b/tools/virsh.c index d58b827..281ffa9 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -1924,6 +1924,13 @@ static const vshCmdInfo info_undefine[] = { static const vshCmdOptDef opts_undefine[] = { {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name or uuid")}, {"managed-save", VSH_OT_BOOL, 0, N_("remove domain managed state file")}, + {"storage", VSH_OT_DATA, VSH_OFLAG_NONE, + N_("remove associated storage volumes (comma separated list of targets " + "or source paths) (see domblklist)")}, + {"remove-all-storage", VSH_OT_BOOL, 0, + N_("remove all associated storage volumes (use with caution)")}, + {"wipe-storage", VSH_OT_BOOL, VSH_OFLAG_NONE, + N_("wipe data on the removed volumes")}, {"snapshots-metadata", VSH_OT_BOOL, 0, N_("remove all domain snapshot metadata, if inactive")}, {NULL, 0, 0, NULL} @@ -1940,6 +1947,9 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) /* User-requested actions. */ bool managed_save = vshCommandOptBool(cmd, "managed-save"); bool snapshots_metadata = vshCommandOptBool(cmd, "snapshots-metadata"); + bool wipe_storage = vshCommandOptBool(cmd, "wipe-storage"); + bool remove_storage = false; + bool remove_all_storage = vshCommandOptBool(cmd, "remove-all-storage"); /* Positive if these items exist. */ int has_managed_save = 0; int has_snapshots_metadata = 0; @@ -1949,6 +1959,22 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) bool snapshots_safe = false; int rc = -1; int running; + /* list of volumes to remove along with this domain */ + char *volumes = NULL; + const char *volume; + char *saveptr = NULL; + char *def = NULL; + char *source = NULL; + char *target = NULL; + int i; + + xmlNodePtr *vol_nodes = NULL; + int nvolumes = 0; + xmlXPathContextPtr ctxt = NULL; + xmlDocPtr doc = NULL; + virStorageVolPtr vol = NULL; + bool vol_del_failed = false; + if (managed_save) { flags |= VIR_DOMAIN_UNDEFINE_MANAGED_SAVE; @@ -1965,6 +1991,18 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) if (!(dom = vshCommandOptDomain(ctl, cmd, &name))) return false; + /* check if a string that should contain list of volumes to remove is present */ + if (vshCommandOptString(cmd, "storage", (const char **)&volumes) > 0) { + /* caution volumes has to be re-assigned as it would be doulbe freed */ + volumes = vshStrdup(ctl, volumes); + + if (remove_all_storage) { + vshError(ctl, _("Specified both --storage and --remove-all-storage")); + goto cleanup; + } + remove_storage = true; + } + /* Do some flag manipulation. The goal here is to disable bits * from flags to reduce the likelihood of a server rejecting * unknown flag bits, as well as to track conditions which are @@ -2027,6 +2065,20 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) snapshots_safe = true; } + /* Stash domain description for later use */ + if (remove_storage || remove_all_storage) { + if (running) { + vshError(ctl, _("Storage volume deletion is supported only on stopped domains")); + goto cleanup; + } + + if (!(def = virDomainGetXMLDesc(dom, 0))) { + vshError(ctl, _("Could not retrieve domain XML description")); + goto cleanup; + } + } + + /* Generally we want to try the new API first. However, while * virDomainUndefineFlags was introduced at the same time as * VIR_DOMAIN_UNDEFINE_MANAGED_SAVE in 0.9.4, the @@ -2076,9 +2128,100 @@ out: ret = true; } else { vshError(ctl, _("Failed to undefine domain %s"), name); + goto cleanup; + } + + /* try to undefine storage volumes associated with this domain, if it's requested */ + if (remove_storage || remove_all_storage) { + ret = false; + doc = virXMLParseStringCtxt(def, _("(domain_definition)"), &ctxt); + if (!doc) + goto cleanup; + + nvolumes = virXPathNodeSet("./devices/disk", ctxt, &vol_nodes); + + if (nvolumes < 0) + goto cleanup; + + for (i = 0; i < nvolumes; i++) { + ctxt->node = vol_nodes[i]; + VIR_FREE(target); + VIR_FREE(source); + if (vol) { + virStorageVolFree(vol); + vol = NULL; + } + + /* get volume source and target paths */ + if (!(target = virXPathString("string(./target/@dev)", ctxt))) { + vshError(ctl, _("Failed to enumerate devices")); + goto cleanup; + } + + if (!(source = virXPathString("string(" + "./source/@file|" + "./source/@dir|" + "./source/@name|" + "./source/@dev)", ctxt)) && + virGetLastError()) + goto cleanup; + + if (volumes) { + volume = strtok_r(volumes, ",", &saveptr); + while (volume) { + if (STREQ_NULLABLE(volume, target) || + STREQ_NULLABLE(volume, source)) + break; + volume = strtok_r(NULL, ",", &saveptr); + } + if (!volume) + continue; + } + + if (!source) + continue; + + if (!(vol = virStorageVolLookupByPath(ctl->conn, source))) { + vshPrint(ctl, + _("Storage volume '%s' is not managed by libvirt. " + "Remove it manually.\n"), source); + virResetLastError(); + continue; + } + + if (wipe_storage) { + vshPrint(ctl, _("Wiping volume '%s' ... "), source); + fflush(stdout); + if (virStorageVolWipe(vol, 0) < 0) { + vshError(ctl, _("Failed! Volume not removed.")); + vol_del_failed = true; + continue; + } else { + vshPrint(ctl, _("Done.\n")); + } + } + + /* delete the volume */ + if (virStorageVolDelete(vol, 0) < 0) { + vshError(ctl, _("Failed to remove storage volume '%s'"), + source); + vol_del_failed = true; + } + vshPrint(ctl, _("Volume '%s' removed.\n"), source); + } + + if (!vol_del_failed) + ret = true; } cleanup: + VIR_FREE(source); + VIR_FREE(target); + VIR_FREE(volumes); + VIR_FREE(def); + VIR_FREE(vol_nodes); + xmlFreeDoc(doc); + xmlXPathFreeContext(ctxt); virDomainFree(dom); return ret; } diff --git a/tools/virsh.pod b/tools/virsh.pod index fe92714..c0b55bd 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -1179,6 +1179,7 @@ Output the device used for the TTY console of the domain. If the information is not available the processes will provide an exit code of 1. =item B<undefine> I<domain-id> [I<--managed-save>] [I<--snapshots-metadata>] +[I<--storage> B<volumes> I<--wipe-storage> I<--remove-all-storage>] Undefine a domain. If the domain is running, this converts it to a transient domain, without stopping it. If the domain is inactive, @@ -1194,6 +1195,23 @@ domain. Without the flag, attempts to undefine an inactive domain with snapshot metadata will fail. If the domain is active, this flag is ignored. +The I<--storage> flag takes a parameter B<volumes>, that is a comma separated +list of volume target names or source paths of storage volumes to be removed +along with the undefined domain. Volumes can be undefined and thus removed only +on inactive domains. Volume deletion is only attempted after the domain is +undefined; if not all of the requested volumes could be deleted, the the +error message indicates what still remains behind. If a volume path is not +found in the domain definition, it's treated as if the volume was successfuly +deleteted. +(See B<domblklist> for list of target names associated to a domain). +Example: --storage vda,vdb,vdc + +The I<--remove-all-storage> flag specifies, that all domain's storage volumes +should be deleted. + +The flag I<--wipe-storage> specifies that the storage volumes should be +wiped before removal. + NOTE: For an inactive domain, the domain name or UUID must be used as the I<domain-id>. -- 1.7.3.4

On 12/13/2011 05:44 AM, Peter Krempa wrote:
Add an option for virsh undefine command, to remove associated storage volumes while undefining a domain. This patch alows the user to remove
s/alows/allows/
associated (libvirt managed ) storage volumes while undefining a domain.
The new option --storage for the undefine command takes a string argument that consists of comma separated list of target or source path of volumes to be undefined. Volumes are removed after the domain has been successfuly undefined,
s/successfuly/successfully/
If a volume is not part of a storage pool, the user is warned to remove the volume in question himself.
Option --wipe-storage may be specified along with this, that ensures the image is wiped before removing.
Option --remove-all-storage enables the user to remove all storage. The name is chosen long as the users shoudl be aware what they're about to
s/shoudl/should/
do. --- Changes to v2 based on reveiw by Eric: ( http://www.redhat.com/archives/libvir-list/2011-September/msg00481.html ) - First undefine the domain, then undefine volumes - Add option to remove all volumes - Fix typos and strange wordings - Change retur value to failure if some operations on volumes fail.
It's been a while - I had flushed it from my mental cache in the meantime :)
@@ -1965,6 +1991,18 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) if (!(dom = vshCommandOptDomain(ctl, cmd, &name))) return false;
+ /* check if a string that should contain list of volumes to remove is present */ + if (vshCommandOptString(cmd, "storage", (const char **)&volumes) > 0) { + /* caution volumes has to be re-assigned as it would be doulbe freed */
s/doulbe/double/ I agree that we have to malloc the end-result into volumes, as strtok_r modifies the string but we are not allowed to modify the result returned by vshCommandOptString. Hmm, I'd almost rather introduce a second, temporary variable in order to avoid the casting and the confusing re-assignment, as in: if (vshCommandOptString(cmd, "storage", &storage) > 0) { volumes = vshStrdup(ctl, storage);
+ + for (i = 0; i < nvolumes; i++) {
+ + if (volumes) { + volume = strtok_r(volumes, ",", &saveptr);
Oops - strtok_r modifies volumes, which means after the first iteration through the outer for loop, you've corrupted it. I think you need to do the strtok_r loop breaking volumes into a char** array prior to entering the for loop.
+ + if (!(vol = virStorageVolLookupByPath(ctl->conn, source))) { + vshPrint(ctl, + _("Storage volume '%s' is not managed by libvirt. " + "Remove it manually.\n"), source);
Suppose the user passed in --storage=/path/to/disk; this message still outputs "Storage volume 'vda' is not managed...". It would be nicer to reuse the user's naming.
=item B<undefine> I<domain-id> [I<--managed-save>] [I<--snapshots-metadata>] +[I<--storage> B<volumes> I<--wipe-storage> I<--remove-all-storage>]
I'd format this as: [{I<--storage B<volumes> | I<--remove-all-storage>} [I<--wipe-storage]]
Undefine a domain. If the domain is running, this converts it to a transient domain, without stopping it. If the domain is inactive, @@ -1194,6 +1195,23 @@ domain. Without the flag, attempts to undefine an inactive domain with snapshot metadata will fail. If the domain is active, this flag is ignored.
+The I<--storage> flag takes a parameter B<volumes>, that is a comma separated +list of volume target names or source paths of storage volumes to be removed +along with the undefined domain. Volumes can be undefined and thus removed only +on inactive domains. Volume deletion is only attempted after the domain is +undefined; if not all of the requested volumes could be deleted, the the +error message indicates what still remains behind. If a volume path is not +found in the domain definition, it's treated as if the volume was successfuly
s/successfuly/successfully/
+deleteted.
s/deleteted/deleted/
+(See B<domblklist> for list of target names associated to a domain). +Example: --storage vda,vdb,vdc
Maybe make it obvious that both formats are possible: Example: --storage vda,/path/to/images/data.img
+ +The I<--remove-all-storage> flag specifies, that all domain's storage volumes
s/,// s/domain's/of the domain's/
+should be deleted. + +The flag I<--wipe-storage> specifies that the storage volumes should be +wiped before removal.
Looks a lot better, but I'm still worried about the correct handling of 'volumes', so I'd be more comfortable seeing a v4. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (2)
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Eric Blake
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Peter Krempa