[libvirt] [PATCH v2 0/4] Precreate storage on migration
Version two of: https://www.redhat.com/archives/libvir-list/2014-November/msg01048.html diff to v1: -Switch from qemuDomainGetBlockInfoImpl() to qemuMonitorBlockStatsUpdateCapacity() -s/alloc/capacity/ -small fixes raised by Peter Michal Privoznik (4): storage: Introduce storagePoolLookupByPath qemuMonitorJSONBlockStatsUpdateCapacity: Don't skip disks qemu_migration: Send disk sizes to the other side qemu_migration: Precreate missing storage src/qemu/qemu_migration.c | 313 ++++++++++++++++++++++++++++++++++++++++--- src/qemu/qemu_monitor_json.c | 12 +- src/storage/storage_driver.c | 36 +++++ src/storage/storage_driver.h | 4 + 4 files changed, 342 insertions(+), 23 deletions(-) -- 2.0.4
While this could be exposed as a public API, it's not done yet as there's no demand for that yet. Anyway, this is just preparing the environment for easier volume creation on the destination. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/storage/storage_driver.c | 36 ++++++++++++++++++++++++++++++++++++ src/storage/storage_driver.h | 4 ++++ 2 files changed, 40 insertions(+) diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 23b63f5..a4f1030 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -1466,6 +1466,42 @@ storageVolLookupByPath(virConnectPtr conn, return ret; } +virStoragePoolPtr +storagePoolLookupByPath(virConnectPtr conn, + const char *path) +{ + size_t i; + virStoragePoolPtr ret = NULL; + char *cleanpath; + + cleanpath = virFileSanitizePath(path); + if (!cleanpath) + return NULL; + + storageDriverLock(); + for (i = 0; i < driver->pools.count && !ret; i++) { + virStoragePoolObjPtr pool = driver->pools.objs[i]; + + virStoragePoolObjLock(pool); + + if (!virStoragePoolObjIsActive(pool)) { + virStoragePoolObjUnlock(pool); + continue; + } + + if (STREQ(path, pool->def->target.path)) { + ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid, + NULL, NULL); + } + + virStoragePoolObjUnlock(pool); + } + + VIR_FREE(cleanpath); + storageDriverUnlock(); + return ret; +} + static int storageVolDeleteInternal(virStorageVolPtr obj, diff --git a/src/storage/storage_driver.h b/src/storage/storage_driver.h index b805ddd..b51760a 100644 --- a/src/storage/storage_driver.h +++ b/src/storage/storage_driver.h @@ -57,6 +57,10 @@ int virStorageFileGetMetadata(virStorageSourcePtr src, int virStorageTranslateDiskSourcePool(virConnectPtr conn, virDomainDiskDefPtr def); +virStoragePoolPtr +storagePoolLookupByPath(virConnectPtr conn, + const char *path); + int storageRegister(void); #endif /* __VIR_STORAGE_DRIVER_H__ */ -- 2.0.4
On 12/01/14 15:57, Michal Privoznik wrote:
While this could be exposed as a public API, it's not done yet as there's no demand for that yet. Anyway, this is just preparing the environment for easier volume creation on the destination.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/storage/storage_driver.c | 36 ++++++++++++++++++++++++++++++++++++ src/storage/storage_driver.h | 4 ++++ 2 files changed, 40 insertions(+)
diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 23b63f5..a4f1030 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -1466,6 +1466,42 @@ storageVolLookupByPath(virConnectPtr conn, return ret; }
A comment describing how this works (mention that only active pools are found), or ...
+virStoragePoolPtr +storagePoolLookupByPath(virConnectPtr conn,
.. rename to LookupByTargetPath perhaps?
+ const char *path) +{ + size_t i; + virStoragePoolPtr ret = NULL; + char *cleanpath; + + cleanpath = virFileSanitizePath(path); + if (!cleanpath) + return NULL; + + storageDriverLock(); + for (i = 0; i < driver->pools.count && !ret; i++) { + virStoragePoolObjPtr pool = driver->pools.objs[i]; + + virStoragePoolObjLock(pool); + + if (!virStoragePoolObjIsActive(pool)) { + virStoragePoolObjUnlock(pool); + continue; + } + + if (STREQ(path, pool->def->target.path)) { + ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid, + NULL, NULL); + } + + virStoragePoolObjUnlock(pool); + } + + VIR_FREE(cleanpath); + storageDriverUnlock(); + return ret; +} +
static int storageVolDeleteInternal(virStorageVolPtr obj, diff --git a/src/storage/storage_driver.h b/src/storage/storage_driver.h index b805ddd..b51760a 100644 --- a/src/storage/storage_driver.h +++ b/src/storage/storage_driver.h @@ -57,6 +57,10 @@ int virStorageFileGetMetadata(virStorageSourcePtr src, int virStorageTranslateDiskSourcePool(virConnectPtr conn, virDomainDiskDefPtr def);
+virStoragePoolPtr +storagePoolLookupByPath(virConnectPtr conn, + const char *path);
Add ATTRIBUTE_NONNULL(2)
+ int storageRegister(void);
#endif /* __VIR_STORAGE_DRIVER_H__ */
ACK with the attribute and a comment about the usage of this func added. Peter
The function queries the block devices visible to qemu ('query-block') and parses the qemu's output. The info is returned in a hash table which is expected to be pre-filled by qemuMonitorJSONGetAllBlockStatsInfo(). However, in the next patch we are not going to call the latter function at all, so we should make the former function add devices into the hash table if not found there. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_monitor_json.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 6e251b3..da80505 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -1889,9 +1889,15 @@ int qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon, if (STRPREFIX(dev_name, QEMU_DRIVE_HOST_PREFIX)) dev_name += strlen(QEMU_DRIVE_HOST_PREFIX); - /* ignore missing info */ - if (!(bstats = virHashLookup(stats, dev_name))) - continue; + if (!(bstats = virHashLookup(stats, dev_name))) { + if (VIR_ALLOC(bstats) < 0) + goto cleanup; + + if (virHashAddEntry(stats, dev_name, bstats) < 0) { + VIR_FREE(bstats); + goto cleanup; + } + } /* drive may be empty */ if (!(inserted = virJSONValueObjectGet(dev, "inserted")) || -- 2.0.4
On 12/01/14 15:57, Michal Privoznik wrote:
The function queries the block devices visible to qemu ('query-block') and parses the qemu's output. The info is returned in a hash table which is expected to be pre-filled by qemuMonitorJSONGetAllBlockStatsInfo(). However, in the next patch we are not going to call the latter function at all, so we should make the former function add devices into the hash table if not found there.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_monitor_json.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 6e251b3..da80505 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -1889,9 +1889,15 @@ int qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon, if (STRPREFIX(dev_name, QEMU_DRIVE_HOST_PREFIX)) dev_name += strlen(QEMU_DRIVE_HOST_PREFIX);
- /* ignore missing info */ - if (!(bstats = virHashLookup(stats, dev_name))) - continue; + if (!(bstats = virHashLookup(stats, dev_name))) { + if (VIR_ALLOC(bstats) < 0) + goto cleanup; + + if (virHashAddEntry(stats, dev_name, bstats) < 0) { + VIR_FREE(bstats); + goto cleanup; + } + }
Move this section ...
/* drive may be empty */ if (!(inserted = virJSONValueObjectGet(dev, "inserted")) ||
after this piece. If the media isn't inserted, there's no need to alloc the field. ACK with that change. Peter
Up 'til now, users need to precreate non-shared storage on migration themselves. This is not very friendly requirement and we should do something about it. In this patch, the migration cookie is extended, so that <nbd/> section does not only contain NBD port, but info on disks being migrated. This patch sends a list of pairs of: <disk target; disk size> to the destination. The actual storage allocation is left for next commit. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_migration.c | 163 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 143 insertions(+), 20 deletions(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index f19e68c..26df9c7 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -141,6 +141,12 @@ typedef struct _qemuMigrationCookieNBD qemuMigrationCookieNBD; typedef qemuMigrationCookieNBD *qemuMigrationCookieNBDPtr; struct _qemuMigrationCookieNBD { int port; /* on which port does NBD server listen for incoming data */ + + size_t ndisks; /* Number of items in @disk array */ + struct { + char *target; /* Disk target */ + unsigned long long capacity; /* And its capacity */ + } *disks; }; typedef struct _qemuMigrationCookie qemuMigrationCookie; @@ -206,6 +212,18 @@ qemuMigrationCookieNetworkFree(qemuMigrationCookieNetworkPtr network) } +static void qemuMigrationCookieNBDFree(qemuMigrationCookieNBDPtr nbd) +{ + if (!nbd) + return; + + while (nbd->ndisks) + VIR_FREE(nbd->disks[--nbd->ndisks].target); + VIR_FREE(nbd->disks); + VIR_FREE(nbd); +} + + static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig) { if (!mig) @@ -213,13 +231,13 @@ static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig) qemuMigrationCookieGraphicsFree(mig->graphics); qemuMigrationCookieNetworkFree(mig->network); + qemuMigrationCookieNBDFree(mig->nbd); VIR_FREE(mig->localHostname); VIR_FREE(mig->remoteHostname); VIR_FREE(mig->name); VIR_FREE(mig->lockState); VIR_FREE(mig->lockDriver); - VIR_FREE(mig->nbd); VIR_FREE(mig->jobInfo); VIR_FREE(mig); } @@ -525,20 +543,69 @@ qemuMigrationCookieAddNetwork(qemuMigrationCookiePtr mig, static int qemuMigrationCookieAddNBD(qemuMigrationCookiePtr mig, - virQEMUDriverPtr driver ATTRIBUTE_UNUSED, + virQEMUDriverPtr driver, virDomainObjPtr vm) { qemuDomainObjPrivatePtr priv = vm->privateData; + virHashTablePtr stats = NULL; + size_t i; + int ret = -1; /* It is not a bug if there already is a NBD data */ if (!mig->nbd && VIR_ALLOC(mig->nbd) < 0) return -1; + if (vm->def->ndisks && + VIR_ALLOC_N(mig->nbd->disks, vm->def->ndisks) < 0) + return -1; + mig->nbd->ndisks = 0; + + for (i = 0; i < vm->def->ndisks; i++) { + virDomainDiskDefPtr disk = vm->def->disks[i]; + qemuBlockStats *entry; + + /* skip shared, RO and source-less disks */ + if (disk->src->shared || disk->src->readonly || + !virDomainDiskGetSource(disk)) + continue; + + if (!stats) { + if (!(stats = virHashCreate(10, virHashValueFree))) + goto cleanup; + + qemuDomainObjEnterMonitor(driver, vm); + if (qemuMonitorBlockStatsUpdateCapacity(priv->mon, stats) < 0) { + qemuDomainObjExitMonitor(driver, vm); + goto cleanup; + } + qemuDomainObjExitMonitor(driver, vm); + + if (!virDomainObjIsActive(vm)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("domain exited meanwhile")); + goto cleanup; + } + } + + if (!disk->info.alias || + !(entry = virHashLookup(stats, disk->info.alias))) + continue; + + if (VIR_STRDUP(mig->nbd->disks[mig->nbd->ndisks].target, + disk->dst) < 0) + goto cleanup; + mig->nbd->disks[mig->nbd->ndisks].capacity = entry->capacity; + mig->nbd->ndisks++; + } + mig->nbd->port = priv->nbdPort; mig->flags |= QEMU_MIGRATION_COOKIE_NBD; - return 0; + ret = 0; + cleanup: + virHashFree(stats); + return ret; } @@ -763,7 +830,18 @@ qemuMigrationCookieXMLFormat(virQEMUDriverPtr driver, virBufferAddLit(buf, "<nbd"); if (mig->nbd->port) virBufferAsprintf(buf, " port='%d'", mig->nbd->port); - virBufferAddLit(buf, "/>\n"); + if (mig->nbd->ndisks) { + virBufferAddLit(buf, ">\n"); + virBufferAdjustIndent(buf, 2); + for (i = 0; i < mig->nbd->ndisks; i++) + virBufferAsprintf(buf, "<disk target='%s' capacity='%llu'/>\n", + mig->nbd->disks[i].target, + mig->nbd->disks[i].capacity); + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</nbd>\n"); + } else { + virBufferAddLit(buf, "/>\n"); + } } if (mig->flags & QEMU_MIGRATION_COOKIE_STATS && mig->jobInfo) @@ -891,6 +969,64 @@ qemuMigrationCookieNetworkXMLParse(xmlXPathContextPtr ctxt) } +static qemuMigrationCookieNBDPtr +qemuMigrationCookieNBDXMLParse(xmlXPathContextPtr ctxt) +{ + qemuMigrationCookieNBDPtr ret = NULL; + char *port = NULL, *capacity = NULL; + size_t i; + int n; + xmlNodePtr *disks = NULL; + xmlNodePtr save_ctxt = ctxt->node; + + if (VIR_ALLOC(ret) < 0) + goto error; + + port = virXPathString("string(./nbd/@port)", ctxt); + if (port && virStrToLong_i(port, NULL, 10, &ret->port) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Malformed nbd port '%s'"), + port); + goto error; + } + + /* Now check if source sent a list of disks to prealloc. We might be + * talking to an older server, so it's not an error if the list is + * missing. */ + if ((n = virXPathNodeSet("./nbd/disk", ctxt, &disks)) > 0) { + if (VIR_ALLOC_N(ret->disks, n) < 0) + goto error; + ret->ndisks = n; + + for (i = 0; i < n; i++) { + ctxt->node = disks[i]; + VIR_FREE(capacity); + + ret->disks[i].target = virXPathString("string(./@target)", ctxt); + capacity = virXPathString("string(./@capacity)", ctxt); + if (virStrToLong_ull(capacity, NULL, 10, + &ret->disks[i].capacity) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Malformed disk capacity: '%s'"), + capacity); + goto error; + } + } + } + + cleanup: + VIR_FREE(port); + VIR_FREE(capacity); + VIR_FREE(disks); + ctxt->node = save_ctxt; + return ret; + error: + qemuMigrationCookieNBDFree(ret); + ret = NULL; + goto cleanup; +} + + static qemuDomainJobInfoPtr qemuMigrationCookieStatisticsXMLParse(xmlXPathContextPtr ctxt) { @@ -1123,22 +1259,9 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig, goto error; if (flags & QEMU_MIGRATION_COOKIE_NBD && - virXPathBoolean("boolean(./nbd)", ctxt)) { - char *port; - - if (VIR_ALLOC(mig->nbd) < 0) - goto error; - - port = virXPathString("string(./nbd/@port)", ctxt); - if (port && virStrToLong_i(port, NULL, 10, &mig->nbd->port) < 0) { - virReportError(VIR_ERR_INTERNAL_ERROR, - _("Malformed nbd port '%s'"), - port); - VIR_FREE(port); - goto error; - } - VIR_FREE(port); - } + virXPathBoolean("boolean(./nbd)", ctxt) && + (!(mig->nbd = qemuMigrationCookieNBDXMLParse(ctxt)))) + goto error; if (flags & QEMU_MIGRATION_COOKIE_STATS && virXPathBoolean("boolean(./statistics)", ctxt) && -- 2.0.4
On 12/01/14 15:57, Michal Privoznik wrote:
Up 'til now, users need to precreate non-shared storage on migration themselves. This is not very friendly requirement and we should do something about it. In this patch, the migration cookie is extended, so that <nbd/> section does not only contain NBD port, but info on disks being migrated. This patch sends a list of pairs of:
<disk target; disk size>
to the destination. The actual storage allocation is left for next commit.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_migration.c | 163 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 143 insertions(+), 20 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index f19e68c..26df9c7 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c
@@ -525,20 +543,69 @@ qemuMigrationCookieAddNetwork(qemuMigrationCookiePtr mig,
static int qemuMigrationCookieAddNBD(qemuMigrationCookiePtr mig, - virQEMUDriverPtr driver ATTRIBUTE_UNUSED, + virQEMUDriverPtr driver, virDomainObjPtr vm) { qemuDomainObjPrivatePtr priv = vm->privateData; + virHashTablePtr stats = NULL; + size_t i; + int ret = -1;
/* It is not a bug if there already is a NBD data */ if (!mig->nbd && VIR_ALLOC(mig->nbd) < 0) return -1;
+ if (vm->def->ndisks && + VIR_ALLOC_N(mig->nbd->disks, vm->def->ndisks) < 0) + return -1; + mig->nbd->ndisks = 0; + + for (i = 0; i < vm->def->ndisks; i++) { + virDomainDiskDefPtr disk = vm->def->disks[i]; + qemuBlockStats *entry; + + /* skip shared, RO and source-less disks */ + if (disk->src->shared || disk->src->readonly || + !virDomainDiskGetSource(disk))
Either report the size for all disks and decide on the destination whether they are eligible to be copied or restrict this to files only. I personally vote for option 1.
+ continue; + + if (!stats) { + if (!(stats = virHashCreate(10, virHashValueFree))) + goto cleanup; + + qemuDomainObjEnterMonitor(driver, vm); + if (qemuMonitorBlockStatsUpdateCapacity(priv->mon, stats) < 0) { + qemuDomainObjExitMonitor(driver, vm); + goto cleanup; + } + qemuDomainObjExitMonitor(driver, vm); + + if (!virDomainObjIsActive(vm)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("domain exited meanwhile")); + goto cleanup; + } + } + + if (!disk->info.alias || + !(entry = virHashLookup(stats, disk->info.alias))) + continue; + + if (VIR_STRDUP(mig->nbd->disks[mig->nbd->ndisks].target, + disk->dst) < 0) + goto cleanup; + mig->nbd->disks[mig->nbd->ndisks].capacity = entry->capacity; + mig->nbd->ndisks++; + } + mig->nbd->port = priv->nbdPort; mig->flags |= QEMU_MIGRATION_COOKIE_NBD;
- return 0; + ret = 0; + cleanup: + virHashFree(stats); + return ret; }
@@ -763,7 +830,18 @@ qemuMigrationCookieXMLFormat(virQEMUDriverPtr driver, virBufferAddLit(buf, "<nbd"); if (mig->nbd->port) virBufferAsprintf(buf, " port='%d'", mig->nbd->port); - virBufferAddLit(buf, "/>\n"); + if (mig->nbd->ndisks) { + virBufferAddLit(buf, ">\n"); + virBufferAdjustIndent(buf, 2); + for (i = 0; i < mig->nbd->ndisks; i++) + virBufferAsprintf(buf, "<disk target='%s' capacity='%llu'/>\n", + mig->nbd->disks[i].target,
formatting of @target should probably use virBufferEscape.
+ mig->nbd->disks[i].capacity); + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</nbd>\n"); + } else { + virBufferAddLit(buf, "/>\n"); + } }
if (mig->flags & QEMU_MIGRATION_COOKIE_STATS && mig->jobInfo)
ACK Peter
Based on previous commit, we can now precreate missing volumes. While digging out the functionality from storage driver would be nicer, if you've seen the code it's nearly impossible. So I'm going from the other end: 1) For given disk target, disk path is looked up. 2) For the disk path, storage pool is looked up, a volume XML is constructed and then passed to virStorageVolCreateXML() which has all the knowledge how to create raw images, (encrypted) qcow(2) images, etc. One of the advantages of this approach is, we don't have to care about image conversion - qemu does that for us. So for instance, users can transform qcow2 into raw on migration (if the correct XML is passed to the migration API). Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_migration.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 26df9c7..9ccfee2 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -58,6 +58,7 @@ #include "virtypedparam.h" #include "virprocess.h" #include "nwfilter_conf.h" +#include "storage/storage_driver.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -1454,6 +1455,152 @@ qemuMigrationRestoreDomainState(virConnectPtr conn, virDomainObjPtr vm) return ret; } + +static int +qemuMigrationPrecreateDisk(virConnectPtr conn, + virDomainDiskDefPtr disk, + unsigned long long capacity) +{ + int ret = -1; + virStoragePoolPtr pool = NULL; + virStorageVolPtr vol = NULL; + char *volName = NULL, *basePath = NULL; + char *volStr = NULL; + virBuffer buf = VIR_BUFFER_INITIALIZER; + const char *format = NULL; + unsigned int flags = 0; + + VIR_DEBUG("Precreate disk type=%s", virStorageTypeToString(disk->src->type)); + + switch ((virStorageType) disk->src->type) { + case VIR_STORAGE_TYPE_FILE: + if (!virDomainDiskGetSource(disk)) { + VIR_DEBUG("Dropping sourceless disk '%s'", + disk->dst); + return 0; + } + + if (VIR_STRDUP(basePath, disk->src->path) < 0) + goto cleanup; + + if (!(volName = strrchr(basePath, '/'))) { + virReportError(VIR_ERR_INVALID_ARG, + _("malformed disk path: %s"), + disk->src->path); + goto cleanup; + } + + *volName = '\0'; + volName++; + + if (!(pool = storagePoolLookupByPath(conn, basePath))) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unable to find pool to %s"), + basePath); + goto cleanup; + } + format = virStorageFileFormatTypeToString(disk->src->format); + if (disk->src->format == VIR_STORAGE_FILE_QCOW2) + flags |= VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA; + break; + + case VIR_STORAGE_TYPE_VOLUME: + if (!(pool = virStoragePoolLookupByName(conn, disk->src->srcpool->pool))) + goto cleanup; + format = virStorageFileFormatTypeToString(disk->src->format); + volName = disk->src->srcpool->volume; + if (disk->src->format == VIR_STORAGE_FILE_QCOW2) + flags |= VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA; + break; + + case VIR_STORAGE_TYPE_BLOCK: + case VIR_STORAGE_TYPE_DIR: + case VIR_STORAGE_TYPE_NETWORK: + case VIR_STORAGE_TYPE_NONE: + case VIR_STORAGE_TYPE_LAST: + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unsupported disk type '%s'"), + virStorageTypeToString(disk->src->type)); + goto cleanup; + break; + } + + virBufferAddLit(&buf, "<volume>\n"); + virBufferAdjustIndent(&buf, 2); + virBufferAsprintf(&buf, "<name>%s</name>", volName); + virBufferAsprintf(&buf, "<capacity>%llu</capacity>\n", capacity); + virBufferAddLit(&buf, "<target>\n"); + virBufferAdjustIndent(&buf, 2); + virBufferAsprintf(&buf, "<format type='%s'/>\n", format); + virBufferAdjustIndent(&buf, -2); + virBufferAddLit(&buf, "</target>\n"); + virBufferAdjustIndent(&buf, -2); + virBufferAddLit(&buf, "</volume>\n"); + + if (!(volStr = virBufferContentAndReset(&buf))) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("unable to create volume XML")); + goto cleanup; + } + + if (!(vol = virStorageVolCreateXML(pool, volStr, flags))) + goto cleanup; + + ret = 0; + cleanup: + VIR_FREE(basePath); + VIR_FREE(volStr); + if (vol) + virStorageVolFree(vol); + if (pool) + virStoragePoolFree(pool); + return ret; +} + + +static int +qemuMigrationPrecreateStorage(virConnectPtr conn, + virQEMUDriverPtr driver ATTRIBUTE_UNUSED, + virDomainObjPtr vm, + qemuMigrationCookieNBDPtr nbd) +{ + int ret = -1; + size_t i = 0; + + if (!nbd || !nbd->ndisks) + return 0; + + for (i = 0; i < nbd->ndisks; i++) { + virDomainDiskDefPtr disk; + int indx; + const char *diskSrcPath; + + VIR_DEBUG("Looking up disk target '%s' (capacity=%lluu)", + nbd->disks[i].target, nbd->disks[i].capacity); + + if ((indx = virDomainDiskIndexByName(vm->def, + nbd->disks[i].target, false)) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unable to find disk by target: %s"), + nbd->disks[i].target); + goto cleanup; + } + + disk = vm->def->disks[indx]; + diskSrcPath = virDomainDiskGetSource(disk); + + VIR_DEBUG("Proceeding with disk source %s", NULLSTR(diskSrcPath)); + + if (qemuMigrationPrecreateDisk(conn, disk, nbd->disks[i].capacity) < 0) + goto cleanup; + } + + ret = 0; + cleanup: + return ret; +} + + /** * qemuMigrationStartNBDServer: * @driver: qemu driver @@ -2838,6 +2985,9 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, goto cleanup; } + if (qemuMigrationPrecreateStorage(dconn, driver, vm, mig->nbd) < 0) + goto cleanup; + if (qemuMigrationJobStart(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0) goto cleanup; qemuMigrationJobSetPhase(driver, vm, QEMU_MIGRATION_PHASE_PREPARE); -- 2.0.4
On 12/01/14 15:57, Michal Privoznik wrote:
Based on previous commit, we can now precreate missing volumes. While digging out the functionality from storage driver would be nicer, if you've seen the code it's nearly impossible. So I'm going from the other end:
1) For given disk target, disk path is looked up. 2) For the disk path, storage pool is looked up, a volume XML is constructed and then passed to virStorageVolCreateXML() which has all the knowledge how to create raw images, (encrypted) qcow(2) images, etc.
One of the advantages of this approach is, we don't have to care about image conversion - qemu does that for us. So for instance, users can transform qcow2 into raw on migration (if the correct XML is passed to the migration API).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_migration.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 26df9c7..9ccfee2 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -58,6 +58,7 @@ #include "virtypedparam.h" #include "virprocess.h" #include "nwfilter_conf.h" +#include "storage/storage_driver.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -1454,6 +1455,152 @@ qemuMigrationRestoreDomainState(virConnectPtr conn, virDomainObjPtr vm) return ret; }
+ +static int +qemuMigrationPrecreateDisk(virConnectPtr conn, + virDomainDiskDefPtr disk, + unsigned long long capacity) +{ + int ret = -1; + virStoragePoolPtr pool = NULL; + virStorageVolPtr vol = NULL; + char *volName = NULL, *basePath = NULL; + char *volStr = NULL; + virBuffer buf = VIR_BUFFER_INITIALIZER; + const char *format = NULL; + unsigned int flags = 0; + + VIR_DEBUG("Precreate disk type=%s", virStorageTypeToString(disk->src->type)); + + switch ((virStorageType) disk->src->type) { + case VIR_STORAGE_TYPE_FILE: + if (!virDomainDiskGetSource(disk)) { + VIR_DEBUG("Dropping sourceless disk '%s'", + disk->dst); + return 0; + } + + if (VIR_STRDUP(basePath, disk->src->path) < 0) + goto cleanup; + + if (!(volName = strrchr(basePath, '/'))) {
For finding the base path you'd normally want to use mdir_name(), but then you wouldn't be able to extract the volume name too.
+ virReportError(VIR_ERR_INVALID_ARG, + _("malformed disk path: %s"), + disk->src->path); + goto cleanup; + } + + *volName = '\0'; + volName++;
I guess this is good enough then.
+ + if (!(pool = storagePoolLookupByPath(conn, basePath))) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unable to find pool to %s"),
"unable to find pool for path '%s'" ?
+ basePath); + goto cleanup; + } + format = virStorageFileFormatTypeToString(disk->src->format); + if (disk->src->format == VIR_STORAGE_FILE_QCOW2) + flags |= VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA; + break; + + case VIR_STORAGE_TYPE_VOLUME: + if (!(pool = virStoragePoolLookupByName(conn, disk->src->srcpool->pool))) + goto cleanup; + format = virStorageFileFormatTypeToString(disk->src->format); + volName = disk->src->srcpool->volume; + if (disk->src->format == VIR_STORAGE_FILE_QCOW2) + flags |= VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA; + break; + + case VIR_STORAGE_TYPE_BLOCK: + case VIR_STORAGE_TYPE_DIR: + case VIR_STORAGE_TYPE_NETWORK: + case VIR_STORAGE_TYPE_NONE: + case VIR_STORAGE_TYPE_LAST: + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unsupported disk type '%s'"),
Possibly a more helpful message: "cannot precreate storage for disk type '%s' ?
+ virStorageTypeToString(disk->src->type)); + goto cleanup; + break; + } + + virBufferAddLit(&buf, "<volume>\n"); + virBufferAdjustIndent(&buf, 2); + virBufferAsprintf(&buf, "<name>%s</name>", volName);
You need to use virBufferEscape for the name
+ virBufferAsprintf(&buf, "<capacity>%llu</capacity>\n", capacity); + virBufferAddLit(&buf, "<target>\n"); + virBufferAdjustIndent(&buf, 2); + virBufferAsprintf(&buf, "<format type='%s'/>\n", format);
Format is okay as we control the strings.
+ virBufferAdjustIndent(&buf, -2); + virBufferAddLit(&buf, "</target>\n"); + virBufferAdjustIndent(&buf, -2); + virBufferAddLit(&buf, "</volume>\n"); + + if (!(volStr = virBufferContentAndReset(&buf))) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("unable to create volume XML")); + goto cleanup; + } + + if (!(vol = virStorageVolCreateXML(pool, volStr, flags))) + goto cleanup; + + ret = 0; + cleanup: + VIR_FREE(basePath); + VIR_FREE(volStr); + if (vol) + virStorageVolFree(vol); + if (pool) + virStoragePoolFree(pool); + return ret; +} + + +static int +qemuMigrationPrecreateStorage(virConnectPtr conn, + virQEMUDriverPtr driver ATTRIBUTE_UNUSED, + virDomainObjPtr vm, + qemuMigrationCookieNBDPtr nbd) +{ + int ret = -1; + size_t i = 0; + + if (!nbd || !nbd->ndisks) + return 0; + + for (i = 0; i < nbd->ndisks; i++) { + virDomainDiskDefPtr disk; + int indx; + const char *diskSrcPath; + + VIR_DEBUG("Looking up disk target '%s' (capacity=%lluu)", + nbd->disks[i].target, nbd->disks[i].capacity); + + if ((indx = virDomainDiskIndexByName(vm->def, + nbd->disks[i].target, false)) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unable to find disk by target: %s"), + nbd->disks[i].target); + goto cleanup; + } + + disk = vm->def->disks[indx]; + diskSrcPath = virDomainDiskGetSource(disk); + + VIR_DEBUG("Proceeding with disk source %s", NULLSTR(diskSrcPath));
The storage pre-creation should be skipped in case the target file already exists as previously the user had to pre-create the file manually. In case we'd do this unconditionally we might break the case somebody is already precreating it.
+ + if (qemuMigrationPrecreateDisk(conn, disk, nbd->disks[i].capacity) < 0) + goto cleanup; + } + + ret = 0; + cleanup: + return ret; +} + + /** * qemuMigrationStartNBDServer: * @driver: qemu driver @@ -2838,6 +2985,9 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, goto cleanup; }
+ if (qemuMigrationPrecreateStorage(dconn, driver, vm, mig->nbd) < 0) + goto cleanup; + if (qemuMigrationJobStart(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0) goto cleanup; qemuMigrationJobSetPhase(driver, vm, QEMU_MIGRATION_PHASE_PREPARE);
Otherwise looks good code-wise, but I don't see any mention of this new feature in the documentation. Peter
participants (2)
-
Michal Privoznik -
Peter Krempa