[libvirt] [PATCH v4] 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 allows 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 successfully 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 should be aware what they're about to do. --- Changes to v3: - fix ton'o'typos (I should install a spell checker.) - add a new variable to hold copy of argument to avoid confusion, typecasting ... - break volume string into tokens just once and store it in an array - add both target and source as volume description ( both are needed, as the user should know which volume he shoud delete, if the domain vanishes ) - reformat argument string in man - add example containing source path tools/virsh.c | 180 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/virsh.pod | 18 ++++++ 2 files changed, 198 insertions(+), 0 deletions(-) diff --git a/tools/virsh.c b/tools/virsh.c index f6571f7..84b5e61 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 +1959,24 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd) bool snapshots_safe = false; int rc = -1; int running; + /* list of volumes to remove along with this domain */ + const char *volumes_arg = NULL; + char *volumes = NULL; + char **volume_tokens = NULL; + char *volume_tok = NULL; + int nvolume_tokens = 0; + char *def = NULL; + char *source = NULL; + char *target = NULL; + int vol_i; + int tok_i; + xmlDocPtr doc = NULL; + xmlXPathContextPtr ctxt = NULL; + xmlNodePtr *vol_nodes = NULL; + int nvolumes = 0; + virStorageVolPtr vol = NULL; + bool vol_del_failed = false; if (managed_save) { flags |= VIR_DOMAIN_UNDEFINE_MANAGED_SAVE; @@ -1965,6 +1993,17 @@ 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", &volumes_arg) > 0) { + volumes = vshStrdup(ctl, volumes_arg); + + 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 +2066,20 @@ 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 +2129,138 @@ 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; + + /* tokenize the string from user and save it's parts into an array */ + if (volumes) { + /* count the delimiters */ + volume_tok = volumes; + nvolume_tokens = 1; /* we need at least one member */ + while (*volume_tok) { + if (*volume_tok == ',') + nvolume_tokens++; + volume_tok++; + } + + volume_tokens = vshCalloc(ctl, nvolume_tokens, sizeof(char *)); + + /* tokenize the input string */ + nvolume_tokens = 0; + volume_tok = volumes; + do { + volume_tokens[nvolume_tokens] = strsep(&volume_tok, ","); + nvolume_tokens++; + } while (volume_tok); + } + + doc = virXMLParseStringCtxt(def, _("(domain_definition)"), &ctxt); + if (!doc) + goto cleanup; + + nvolumes = virXPathNodeSet("./devices/disk", ctxt, &vol_nodes); + + if (nvolumes < 0) + goto cleanup; + + for (vol_i = 0; vol_i < nvolumes; vol_i++) { + ctxt->node = vol_nodes[vol_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; + + /* lookup if volume was selected by user */ + if (volumes) { + volume_tok = NULL; + for (tok_i = 0; tok_i < nvolume_tokens; tok_i++) { + if (volume_tokens[tok_i] && + (STREQ_NULLABLE(volume_tokens[tok_i], target) || + STREQ_NULLABLE(volume_tokens[tok_i], source))) { + volume_tok = volume_tokens[tok_i]; + volume_tokens[tok_i] = NULL; + break; + } + } + if (!volume_tok) + continue; + } + + if (!source) + continue; + + if (!(vol = virStorageVolLookupByPath(ctl->conn, source))) { + vshPrint(ctl, + _("Storage volume '%s'(%s) is not managed by libvirt. " + "Remove it manually.\n"), target, source); + virResetLastError(); + continue; + } + + if (wipe_storage) { + vshPrint(ctl, _("Wiping volume '%s'(%s) ... "), target, 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'(%s)"), + target, source); + vol_del_failed = true; + } + vshPrint(ctl, _("Volume '%s' removed.\n"), volume_tok?volume_tok:source); + } + + /* print volumes specified by user that were not found in domain definition */ + if (volumes) { + for (tok_i = 0; tok_i < nvolume_tokens; tok_i++) { + if (volume_tokens[tok_i]) + vshPrint(ctl, _("Volume '%s' was not found in domain's " + "definition.\n"), + volume_tokens[tok_i]); + } + } + + if (!vol_del_failed) + ret = true; } cleanup: + VIR_FREE(source); + VIR_FREE(target); + VIR_FREE(volumes); + VIR_FREE(volume_tokens); + 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 c468f13..3976166 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -1181,6 +1181,7 @@ 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<--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, @@ -1196,6 +1197,23 @@ 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 +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 successfully +deleteted. +(See B<domblklist> for list of target names associated to a domain). +Example: --storage vda,/path/to/storage.img + +The I<--remove-all-storage> flag specifies that all of the 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