[libvirt RFC 01/24] qemu_block: extract block commit code to separate function

Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/qemu/qemu_block.c | 197 +++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_block.h | 9 ++ src/qemu/qemu_driver.c | 181 +------------------------------------ 3 files changed, 207 insertions(+), 180 deletions(-) diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c index b82e3311e1..c0c4088cbf 100644 --- a/src/qemu/qemu_block.c +++ b/src/qemu/qemu_block.c @@ -3201,3 +3201,200 @@ qemuBlockExportAddNBD(virDomainObj *vm, return qemuMonitorBlockExportAdd(priv->mon, &nbdprops); } + + +int +qemuBlockCommit(virDomainObj *vm, + virQEMUDriver *driver, + const char *path, + const char *base, + const char *top, + unsigned long bandwidth, + unsigned int flags) +{ + qemuDomainObjPrivate *priv = vm->privateData; + int rc = -1; + virDomainDiskDef *disk = NULL; + virStorageSource *topSource; + virStorageSource *baseSource = NULL; + virStorageSource *top_parent = NULL; + bool clean_access = false; + g_autofree char *backingPath = NULL; + qemuBlockJobData *job = NULL; + g_autoptr(virStorageSource) mirror = NULL; + + if (virDomainObjCheckActive(vm) < 0) + return -1; + + /* Convert bandwidth MiB to bytes, if necessary */ + if (!(flags & VIR_DOMAIN_BLOCK_COMMIT_BANDWIDTH_BYTES)) { + if (bandwidth > LLONG_MAX >> 20) { + virReportError(VIR_ERR_OVERFLOW, + _("bandwidth must be less than %llu"), + LLONG_MAX >> 20); + return -1; + } + bandwidth <<= 20; + } + + if (!(disk = qemuDomainDiskByName(vm->def, path))) + return -1; + + if (!qemuDomainDiskBlockJobIsSupported(disk)) + return -1; + + if (virStorageSourceIsEmpty(disk->src)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("disk %s has no source file to be committed"), + disk->dst); + return -1; + } + + if (qemuDomainDiskBlockJobIsActive(disk)) + return -1; + + if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0) + return -1; + + if (!top || STREQ(top, disk->dst)) + topSource = disk->src; + else if (!(topSource = virStorageSourceChainLookup(disk->src, NULL, top, + disk->dst, &top_parent))) + return -1; + + if (topSource == disk->src) { + /* XXX Should we auto-pivot when COMMIT_ACTIVE is not specified? */ + if (!(flags & VIR_DOMAIN_BLOCK_COMMIT_ACTIVE)) { + virReportError(VIR_ERR_INVALID_ARG, + _("commit of '%s' active layer requires active flag"), + disk->dst); + return -1; + } + } else if (flags & VIR_DOMAIN_BLOCK_COMMIT_ACTIVE) { + virReportError(VIR_ERR_INVALID_ARG, + _("active commit requested but '%s' is not active"), + topSource->path); + return -1; + } + + if (!virStorageSourceHasBacking(topSource)) { + virReportError(VIR_ERR_INVALID_ARG, + _("top '%s' in chain for '%s' has no backing file"), + topSource->path, path); + return -1; + } + + if (!base && (flags & VIR_DOMAIN_BLOCK_COMMIT_SHALLOW)) + baseSource = topSource->backingStore; + else if (!(baseSource = virStorageSourceChainLookup(disk->src, topSource, + base, disk->dst, NULL))) + return -1; + + if ((flags & VIR_DOMAIN_BLOCK_COMMIT_SHALLOW) && + baseSource != topSource->backingStore) { + virReportError(VIR_ERR_INVALID_ARG, + _("base '%s' is not immediately below '%s' in chain " + "for '%s'"), + base, topSource->path, path); + return -1; + } + + /* For an active commit, clone enough of the base to act as the mirror */ + if (topSource == disk->src) { + if (!(mirror = virStorageSourceCopy(baseSource, false))) + return -1; + if (virStorageSourceInitChainElement(mirror, + disk->src, + true) < 0) + return -1; + } + + if (flags & VIR_DOMAIN_BLOCK_COMMIT_RELATIVE && + topSource != disk->src) { + if (top_parent && + qemuBlockUpdateRelativeBacking(vm, top_parent, disk->src) < 0) + return -1; + + if (virStorageSourceGetRelativeBackingPath(topSource, baseSource, + &backingPath) < 0) + return -1; + + if (!backingPath) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("can't keep relative backing relationship")); + return -1; + } + } + + /* For the commit to succeed, we must allow qemu to open both the + * 'base' image and the parent of 'top' as read/write; 'top' might + * not have a parent, or might already be read-write. XXX It + * would also be nice to revert 'base' to read-only, as well as + * revoke access to files removed from the chain, when the commit + * operation succeeds, but doing that requires tracking the + * operation in XML across libvirtd restarts. */ + clean_access = true; + if (qemuDomainStorageSourceAccessAllow(driver, vm, baseSource, + false, false, false) < 0) + goto error; + + if (top_parent && top_parent != disk->src) { + /* While top_parent is topmost image, we don't need to remember its + * owner as it will be overwritten upon finishing the commit. Hence, + * pass chainTop = false. */ + if (qemuDomainStorageSourceAccessAllow(driver, vm, top_parent, + false, false, false) < 0) + goto error; + } + + if (!(job = qemuBlockJobDiskNewCommit(vm, disk, top_parent, topSource, + baseSource, + flags & VIR_DOMAIN_BLOCK_COMMIT_DELETE, + flags))) + goto error; + + disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE; + + if (!backingPath && top_parent && + !(backingPath = qemuBlockGetBackingStoreString(baseSource, false))) + goto error; + + qemuDomainObjEnterMonitor(vm); + + rc = qemuMonitorBlockCommit(priv->mon, + qemuDomainDiskGetTopNodename(disk), + job->name, + topSource->nodeformat, + baseSource->nodeformat, + backingPath, bandwidth); + + qemuDomainObjExitMonitor(vm); + + if (rc < 0) + goto error; + + if (mirror) { + disk->mirror = g_steal_pointer(&mirror); + disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT; + } + qemuBlockJobStarted(job, vm); + + return 0; + + error: + if (clean_access) { + virErrorPtr orig_err; + virErrorPreserveLast(&orig_err); + /* Revert access to read-only, if possible. */ + qemuDomainStorageSourceAccessAllow(driver, vm, baseSource, + true, false, false); + if (top_parent && top_parent != disk->src) + qemuDomainStorageSourceAccessAllow(driver, vm, top_parent, + true, false, false); + + virErrorRestore(&orig_err); + } + qemuBlockJobStartupFinalize(vm, job); + + return -1; +} diff --git a/src/qemu/qemu_block.h b/src/qemu/qemu_block.h index 8a3a10344e..be81ec3c7f 100644 --- a/src/qemu/qemu_block.h +++ b/src/qemu/qemu_block.h @@ -276,3 +276,12 @@ qemuBlockExportAddNBD(virDomainObj *vm, const char *exportname, bool writable, const char *bitmap); + +int +qemuBlockCommit(virDomainObj *vm, + virQEMUDriver *driver, + const char *path, + const char *base, + const char *top, + unsigned long bandwidth, + unsigned int flags); diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 707f4cc1bb..d353b6df93 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -15375,18 +15375,8 @@ qemuDomainBlockCommit(virDomainPtr dom, unsigned int flags) { virQEMUDriver *driver = dom->conn->privateData; - qemuDomainObjPrivate *priv; virDomainObj *vm = NULL; int ret = -1; - virDomainDiskDef *disk = NULL; - virStorageSource *topSource; - virStorageSource *baseSource = NULL; - virStorageSource *top_parent = NULL; - bool clean_access = false; - g_autofree char *backingPath = NULL; - unsigned long long speed = bandwidth; - qemuBlockJobData *job = NULL; - g_autoptr(virStorageSource) mirror = NULL; virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW | VIR_DOMAIN_BLOCK_COMMIT_ACTIVE | @@ -15396,7 +15386,6 @@ qemuDomainBlockCommit(virDomainPtr dom, if (!(vm = qemuDomainObjFromDomain(dom))) goto cleanup; - priv = vm->privateData; if (virDomainBlockCommitEnsureACL(dom->conn, vm->def) < 0) goto cleanup; @@ -15404,176 +15393,8 @@ qemuDomainBlockCommit(virDomainPtr dom, if (qemuDomainObjBeginJob(vm, VIR_JOB_MODIFY) < 0) goto cleanup; - if (virDomainObjCheckActive(vm) < 0) - goto endjob; + ret = qemuBlockCommit(vm, driver, path, base, top, bandwidth, flags); - /* Convert bandwidth MiB to bytes, if necessary */ - if (!(flags & VIR_DOMAIN_BLOCK_COMMIT_BANDWIDTH_BYTES)) { - if (speed > LLONG_MAX >> 20) { - virReportError(VIR_ERR_OVERFLOW, - _("bandwidth must be less than %llu"), - LLONG_MAX >> 20); - goto endjob; - } - speed <<= 20; - } - - if (!(disk = qemuDomainDiskByName(vm->def, path))) - goto endjob; - - if (!qemuDomainDiskBlockJobIsSupported(disk)) - goto endjob; - - if (virStorageSourceIsEmpty(disk->src)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("disk %s has no source file to be committed"), - disk->dst); - goto endjob; - } - - if (qemuDomainDiskBlockJobIsActive(disk)) - goto endjob; - - if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0) - goto endjob; - - if (!top || STREQ(top, disk->dst)) - topSource = disk->src; - else if (!(topSource = virStorageSourceChainLookup(disk->src, NULL, top, - disk->dst, &top_parent))) - goto endjob; - - if (topSource == disk->src) { - /* XXX Should we auto-pivot when COMMIT_ACTIVE is not specified? */ - if (!(flags & VIR_DOMAIN_BLOCK_COMMIT_ACTIVE)) { - virReportError(VIR_ERR_INVALID_ARG, - _("commit of '%s' active layer requires active flag"), - disk->dst); - goto endjob; - } - } else if (flags & VIR_DOMAIN_BLOCK_COMMIT_ACTIVE) { - virReportError(VIR_ERR_INVALID_ARG, - _("active commit requested but '%s' is not active"), - topSource->path); - goto endjob; - } - - if (!virStorageSourceHasBacking(topSource)) { - virReportError(VIR_ERR_INVALID_ARG, - _("top '%s' in chain for '%s' has no backing file"), - topSource->path, path); - goto endjob; - } - - if (!base && (flags & VIR_DOMAIN_BLOCK_COMMIT_SHALLOW)) - baseSource = topSource->backingStore; - else if (!(baseSource = virStorageSourceChainLookup(disk->src, topSource, - base, disk->dst, NULL))) - goto endjob; - - if ((flags & VIR_DOMAIN_BLOCK_COMMIT_SHALLOW) && - baseSource != topSource->backingStore) { - virReportError(VIR_ERR_INVALID_ARG, - _("base '%s' is not immediately below '%s' in chain " - "for '%s'"), - base, topSource->path, path); - goto endjob; - } - - /* For an active commit, clone enough of the base to act as the mirror */ - if (topSource == disk->src) { - if (!(mirror = virStorageSourceCopy(baseSource, false))) - goto endjob; - if (virStorageSourceInitChainElement(mirror, - disk->src, - true) < 0) - goto endjob; - } - - if (flags & VIR_DOMAIN_BLOCK_COMMIT_RELATIVE && - topSource != disk->src) { - if (top_parent && - qemuBlockUpdateRelativeBacking(vm, top_parent, disk->src) < 0) - goto endjob; - - if (virStorageSourceGetRelativeBackingPath(topSource, baseSource, - &backingPath) < 0) - goto endjob; - - if (!backingPath) { - virReportError(VIR_ERR_OPERATION_INVALID, "%s", - _("can't keep relative backing relationship")); - goto endjob; - } - } - - /* For the commit to succeed, we must allow qemu to open both the - * 'base' image and the parent of 'top' as read/write; 'top' might - * not have a parent, or might already be read-write. XXX It - * would also be nice to revert 'base' to read-only, as well as - * revoke access to files removed from the chain, when the commit - * operation succeeds, but doing that requires tracking the - * operation in XML across libvirtd restarts. */ - clean_access = true; - if (qemuDomainStorageSourceAccessAllow(driver, vm, baseSource, - false, false, false) < 0) - goto endjob; - - if (top_parent && top_parent != disk->src) { - /* While top_parent is topmost image, we don't need to remember its - * owner as it will be overwritten upon finishing the commit. Hence, - * pass chainTop = false. */ - if (qemuDomainStorageSourceAccessAllow(driver, vm, top_parent, - false, false, false) < 0) - goto endjob; - } - - if (!(job = qemuBlockJobDiskNewCommit(vm, disk, top_parent, topSource, - baseSource, - flags & VIR_DOMAIN_BLOCK_COMMIT_DELETE, - flags))) - goto endjob; - - disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE; - - if (!backingPath && top_parent && - !(backingPath = qemuBlockGetBackingStoreString(baseSource, false))) - goto endjob; - - qemuDomainObjEnterMonitor(vm); - - ret = qemuMonitorBlockCommit(priv->mon, - qemuDomainDiskGetTopNodename(disk), - job->name, - topSource->nodeformat, - baseSource->nodeformat, - backingPath, speed); - - qemuDomainObjExitMonitor(vm); - - if (ret < 0) - goto endjob; - - if (mirror) { - disk->mirror = g_steal_pointer(&mirror); - disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT; - } - qemuBlockJobStarted(job, vm); - - endjob: - if (ret < 0 && clean_access) { - virErrorPtr orig_err; - virErrorPreserveLast(&orig_err); - /* Revert access to read-only, if possible. */ - qemuDomainStorageSourceAccessAllow(driver, vm, baseSource, - true, false, false); - if (top_parent && top_parent != disk->src) - qemuDomainStorageSourceAccessAllow(driver, vm, top_parent, - true, false, false); - - virErrorRestore(&orig_err); - } - qemuBlockJobStartupFinalize(vm, job); qemuDomainObjEndJob(vm); cleanup: -- 2.37.2