On 05/22/2014 07:47 AM, Peter Krempa wrote: Not necessarily ideal. Reading metadata from a file that is also simultaneously opened read-write by qemu might, in super-rare circumstances, hit a race where qemu is in the middle of updating metadata due to the completion of some job that was started before the libvirtd restart. Although qcow2 has a hard cap of header fitting in one cluster (typically 64k) (at least, after CVE-2014-0144, qemu.git commit 24342f2ca), it is still plausible that qemu is updating the qcow2 header via sectors (perhaps as small as 512-byte chunks) rather than by full clusters; and there are scenarios where an update touches two non-adjacent sectors (such as adjusting the backing file name), such that if a reader sees the old content of one sector but the new content of the other, then it is completely broken in interpreting the data. A slightly safer alternative might be using a QMP command to ask qemu what the backing chain currently is when we reconnect - although that may require correlation back to filenames we passed in, since in the face of fd passing, qemu may only know the name "/dev/fdset/NNN" instead of the filename the earlier libvirtd opened and passed in by fd. And that presupposes that qemu can always be trusted (we don't want to introduce a CVE where a guest that compromises qemu into returning bogus QMP results can then cause libvirt to mismanage the host filesystem). So with those points made, a metadata read race is extremely rare, and I see no point in implementing a half-way solution that requires parsing a QMP command if we are eventually going to switch over to full XML tracking anyways. Therefore, since _this_ patch is a clear improvement (even if not theoretically perfect), we shouldn't hold it up waiting for some other solution. ACK as-is. and thanks for the comment to remind us what we should improve. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org

Refactor the function to accept a virStorageSourcePtr instead of just the path, add a check to run it only on local storage and fix callers (possibly by using a newly introduced wrapper that wraps a path in the virStorageSource struct for legacy code) --- Notes: Version 2: - V1 acked by Eric with comment cleanup src/qemu/qemu_driver.c | 77 ++++++++++++++++++++++++++++++++------------------ 1 file changed, 49 insertions(+), 28 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 6fda50d..d3e14ea 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -12020,22 +12020,26 @@ static int qemuDomainPrepareDiskChainElement(virQEMUDriverPtr driver, virDomainObjPtr vm, virDomainDiskDefPtr disk, - const char *file, + virStorageSourcePtr elem, qemuDomainDiskChainMode mode) { /* The easiest way to label a single file with the same * permissions it would have as if part of the disk chain is to * temporarily modify the disk in place. */ - char *origsrc = disk->src.path; - int origformat = disk->src.format; - virStorageSourcePtr origchain = disk->src.backingStore; + virStorageSource origdisk; bool origreadonly = disk->readonly; + virQEMUDriverConfigPtr cfg = NULL; int ret = -1; - virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver); - disk->src.path = (char *) file; /* casting away const is safe here */ - disk->src.format = VIR_STORAGE_FILE_RAW; - disk->src.backingStore = NULL; + /* XXX Labelling of non-local files isn't currently supported */ + if (virStorageSourceGetActualType(&disk->src) == VIR_STORAGE_TYPE_NETWORK) + return 0; + + cfg = virQEMUDriverGetConfig(driver); + + /* XXX This would be easier when disk->src will be a pointer */ + memcpy(&origdisk, &disk->src, sizeof(origdisk)); + memcpy(&disk->src, elem, sizeof(*elem)); disk->readonly = mode == VIR_DISK_CHAIN_READ_ONLY; if (mode == VIR_DISK_CHAIN_NO_ACCESS) { @@ -12058,9 +12062,7 @@ qemuDomainPrepareDiskChainElement(virQEMUDriverPtr driver, ret = 0; cleanup: - disk->src.path = origsrc; - disk->src.format = origformat; - disk->src.backingStore = origchain; + memcpy(&disk->src, &origdisk, sizeof(origdisk)); disk->readonly = origreadonly; virObjectUnref(cfg); return ret; @@ -12071,6 +12073,25 @@ qemuDomainPrepareDiskChainElement(virQEMUDriverPtr driver, * is sent but failed, and number of frozen filesystems on success. If -2 is * returned, FSThaw should be called revert the quiesced status. */ static int +qemuDomainPrepareDiskChainElementPath(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainDiskDefPtr disk, + const char *file, + qemuDomainDiskChainMode mode) +{ + virStorageSource src; + + memset(&src, 0, sizeof(src)); + + src.type = VIR_STORAGE_TYPE_FILE; + src.format = VIR_STORAGE_FILE_RAW; + src.path = (char *) file; /* casting away const is safe here */ + + return qemuDomainPrepareDiskChainElement(driver, vm, disk, &src, mode); +} + + +static int qemuDomainSnapshotFSFreeze(virQEMUDriverPtr driver, virDomainObjPtr vm, const char **mountpoints, @@ -12829,9 +12850,9 @@ qemuDomainSnapshotCreateSingleDiskActive(virQEMUDriverPtr driver, VIR_FORCE_CLOSE(fd); } - if (qemuDomainPrepareDiskChainElement(driver, vm, disk, source, + if (qemuDomainPrepareDiskChainElement(driver, vm, disk, &snap->src, VIR_DISK_CHAIN_READ_WRITE) < 0) { - qemuDomainPrepareDiskChainElement(driver, vm, disk, source, + qemuDomainPrepareDiskChainElement(driver, vm, disk, &snap->src, VIR_DISK_CHAIN_NO_ACCESS); goto cleanup; } @@ -12962,7 +12983,7 @@ qemuDomainSnapshotUndoSingleDiskActive(virQEMUDriverPtr driver, (persistDisk && VIR_STRDUP(persistSource, source) < 0)) goto cleanup; - qemuDomainPrepareDiskChainElement(driver, vm, disk, disk->src.path, + qemuDomainPrepareDiskChainElement(driver, vm, disk, &disk->src, VIR_DISK_CHAIN_NO_ACCESS); if (need_unlink && virStorageFileStat(&disk->src, &st) == 0 && S_ISREG(st.st_mode) && @@ -15276,10 +15297,10 @@ qemuDomainBlockCopy(virDomainObjPtr vm, if (VIR_STRDUP(mirror, dest) < 0) goto endjob; - if (qemuDomainPrepareDiskChainElement(driver, vm, disk, dest, - VIR_DISK_CHAIN_READ_WRITE) < 0) { - qemuDomainPrepareDiskChainElement(driver, vm, disk, dest, - VIR_DISK_CHAIN_NO_ACCESS); + if (qemuDomainPrepareDiskChainElementPath(driver, vm, disk, dest, + VIR_DISK_CHAIN_READ_WRITE) < 0) { + qemuDomainPrepareDiskChainElementPath(driver, vm, disk, dest, + VIR_DISK_CHAIN_NO_ACCESS); goto endjob; } @@ -15290,8 +15311,8 @@ qemuDomainBlockCopy(virDomainObjPtr vm, virDomainAuditDisk(vm, NULL, dest, "mirror", ret >= 0); qemuDomainObjExitMonitor(driver, vm); if (ret < 0) { - qemuDomainPrepareDiskChainElement(driver, vm, disk, dest, - VIR_DISK_CHAIN_NO_ACCESS); + qemuDomainPrepareDiskChainElementPath(driver, vm, disk, dest, + VIR_DISK_CHAIN_NO_ACCESS); goto endjob; } @@ -15468,12 +15489,12 @@ qemuDomainBlockCommit(virDomainPtr dom, * operation succeeds, but doing that requires tracking the * operation in XML across libvirtd restarts. */ clean_access = true; - if (qemuDomainPrepareDiskChainElement(driver, vm, disk, baseSource->path, + if (qemuDomainPrepareDiskChainElement(driver, vm, disk, baseSource, VIR_DISK_CHAIN_READ_WRITE) < 0 || (top_parent && top_parent != disk->src.path && - qemuDomainPrepareDiskChainElement(driver, vm, disk, - top_parent, - VIR_DISK_CHAIN_READ_WRITE) < 0)) + qemuDomainPrepareDiskChainElementPath(driver, vm, disk, + top_parent, + VIR_DISK_CHAIN_READ_WRITE) < 0)) goto endjob; /* Start the commit operation. Pass the user's original spelling, @@ -15491,12 +15512,12 @@ qemuDomainBlockCommit(virDomainPtr dom, endjob: if (ret < 0 && clean_access) { /* Revert access to read-only, if possible. */ - qemuDomainPrepareDiskChainElement(driver, vm, disk, baseSource->path, + qemuDomainPrepareDiskChainElement(driver, vm, disk, baseSource, VIR_DISK_CHAIN_READ_ONLY); if (top_parent && top_parent != disk->src.path) - qemuDomainPrepareDiskChainElement(driver, vm, disk, - top_parent, - VIR_DISK_CHAIN_READ_ONLY); + qemuDomainPrepareDiskChainElementPath(driver, vm, disk, + top_parent, + VIR_DISK_CHAIN_READ_ONLY); } if (!qemuDomainObjEndJob(driver, vm)) vm = NULL; -- 1.9.3

Skip networked storage but continue iteration through backing chain to iterate through all the local paths in the backing chain. --- Notes: Version 2: - no change, v1 already ACKed by Eric src/conf/domain_conf.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 1ddedac..4bc71c8 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -18686,34 +18686,37 @@ virDomainDiskDefForeachPath(virDomainDiskDefPtr disk, int ret = -1; size_t depth = 0; virStorageSourcePtr tmp; - const char *path = virDomainDiskGetSource(disk); - int type = virDomainDiskGetType(disk); + char *brokenRaw = NULL; - if (!path || type == VIR_STORAGE_TYPE_NETWORK || - (type == VIR_STORAGE_TYPE_VOLUME && - disk->src.srcpool && - disk->src.srcpool->mode == VIR_STORAGE_SOURCE_POOL_MODE_DIRECT)) - return 0; - - if (iter(disk, path, 0, opaque) < 0) - goto cleanup; + if (!ignoreOpenFailure) { + if (virStorageFileChainGetBroken(&disk->src, &brokenRaw) < 0) + goto cleanup; - tmp = disk->src.backingStore; - while (tmp && virStorageIsFile(tmp->path)) { - if (!ignoreOpenFailure && tmp->backingStoreRaw && !tmp->backingStore) { + if (brokenRaw) { virReportError(VIR_ERR_INTERNAL_ERROR, _("unable to visit backing chain file %s"), - tmp->backingStoreRaw); + brokenRaw); goto cleanup; } - if (iter(disk, tmp->path, ++depth, opaque) < 0) - goto cleanup; - tmp = tmp->backingStore; + } + + for (tmp = &disk->src; tmp; tmp = tmp->backingStore) { + int actualType = virStorageSourceGetActualType(tmp); + /* execute the callback only for local storage */ + if (actualType != VIR_STORAGE_TYPE_NETWORK && + actualType != VIR_STORAGE_TYPE_VOLUME && + tmp->path) { + if (iter(disk, tmp->path, depth, opaque) < 0) + goto cleanup; + } + + depth++; } ret = 0; cleanup: + VIR_FREE(brokenRaw); return ret; } -- 1.9.3

On 05/22/2014 07:47 AM, Peter Krempa wrote: ACK with one more nit. Previous ack on 4 and 5 still stands, too. Worth adding the space before { as long as you are touching this line. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org

On 05/22/2014 07:47 AM, Peter Krempa wrote: s/shamelesly/shamelessly/ Oh slick - the earlier patch that adds protocol==0 as "none" rather than "nbd" makes this message tolerable even for non-network storage types. Less special-casing is always good :) Isn't this supposed to be 'return -2' according to the function documentation? ACK if you agree about the return value fix, and if it is the only change you make besides the typo fix. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org

Different protocols have different means to uniquely identify a storage file. This patch implements a storage driver API to retrieve a unique string describing a volume. The current implementation works for local storage only and returns the canonical path of the volume. To add caching support the local filesystem driver now has a private structure holding the cached string, which is created only when it's initially accessed. This patch provides the implementation for local files only for start. --- src/storage/storage_backend.h | 3 +++ src/storage/storage_backend_fs.c | 49 ++++++++++++++++++++++++++++++++++++++++ src/storage/storage_driver.c | 30 ++++++++++++++++++++++++ src/storage/storage_driver.h | 1 + 4 files changed, 83 insertions(+) diff --git a/src/storage/storage_backend.h b/src/storage/storage_backend.h index 6be5ca7..5d71cde 100644 --- a/src/storage/storage_backend.h +++ b/src/storage/storage_backend.h @@ -195,6 +195,8 @@ typedef ssize_t ssize_t max_len, char **buf); +typedef const char * +(*virStorageFileBackendGetUniqueIdentifier)(virStorageSourcePtr src); virStorageFileBackendPtr virStorageFileBackendForType(int type, int protocol); @@ -211,6 +213,7 @@ struct _virStorageFileBackend { virStorageFileBackendInit backendInit; virStorageFileBackendDeinit backendDeinit; virStorageFileBackendReadHeader storageFileReadHeader; + virStorageFileBackendGetUniqueIdentifier storageFileGetUniqueIdentifier; /* The following group of callbacks is expected to set errno * and return -1 on error. No libvirt error shall be reported */ diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c index 33551e7..1f436fa 100644 --- a/src/storage/storage_backend_fs.c +++ b/src/storage/storage_backend_fs.c @@ -1339,6 +1339,14 @@ virStorageBackend virStorageBackendNetFileSystem = { }; +typedef struct _virStorageFileBackendFsPriv virStorageFileBackendFsPriv; +typedef virStorageFileBackendFsPriv *virStorageFileBackendFsPrivPtr; + +struct _virStorageFileBackendFsPriv { + char *uid; /* unique file identifier (canonical path) */ +}; + + static void virStorageFileBackendFileDeinit(virStorageSourcePtr src) { @@ -1346,16 +1354,27 @@ virStorageFileBackendFileDeinit(virStorageSourcePtr src) virStorageTypeToString(virStorageSourceGetActualType(src)), src->path); + virStorageFileBackendFsPrivPtr priv = src->drv->priv; + + VIR_FREE(priv->uid); + VIR_FREE(priv); } static int virStorageFileBackendFileInit(virStorageSourcePtr src) { + virStorageFileBackendFsPrivPtr priv = NULL; + VIR_DEBUG("initializing FS storage file %p (%s:%s)", src, virStorageTypeToString(virStorageSourceGetActualType(src)), src->path); + if (VIR_ALLOC(priv) < 0) + return -1; + + src->drv->priv = priv; + return 0; } @@ -1403,6 +1422,23 @@ virStorageFileBackendFileReadHeader(virStorageSourcePtr src, } +static const char * +virStorageFileBackendFileGetUniqueIdentifier(virStorageSourcePtr src) +{ + virStorageFileBackendFsPrivPtr priv = src->drv->priv; + + if (!priv->uid) { + if (!(priv->uid = canonicalize_file_name(src->path))) { + virReportSystemError(errno, _("can't canonicalize path '%s'"), + src->path); + return NULL; + } + } + + return priv->uid; +} + + virStorageFileBackend virStorageFileBackendFile = { .type = VIR_STORAGE_TYPE_FILE, @@ -1412,6 +1448,8 @@ virStorageFileBackend virStorageFileBackendFile = { .storageFileUnlink = virStorageFileBackendFileUnlink, .storageFileStat = virStorageFileBackendFileStat, .storageFileReadHeader = virStorageFileBackendFileReadHeader, + + .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, }; @@ -1423,7 +1461,18 @@ virStorageFileBackend virStorageFileBackendBlock = { .storageFileStat = virStorageFileBackendFileStat, .storageFileReadHeader = virStorageFileBackendFileReadHeader, + + .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, }; +virStorageFileBackend virStorageFileBackendDir = { + .type = VIR_STORAGE_TYPE_DIR, + + .backendInit = virStorageFileBackendFileInit, + .backendDeinit = virStorageFileBackendFileDeinit, + + .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, +}; + #endif /* WITH_STORAGE_FS */ diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 3019531..2036bfd 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -2987,3 +2987,33 @@ virStorageFileReadHeader(virStorageSourcePtr src, return ret; } + + +/* + * virStorageFileGetUniqueIdentifier: Get a unique string describing the volume + * + * @src: file structure pointing to the file + * + * Returns a string uniquely describing a single volume (canonical path). + * The string shall not be freed. Returns NULL on error and sets a libvirt + * error code */ +const char * +virStorageFileGetUniqueIdentifier(virStorageSourcePtr src) +{ + if (!virStorageFileIsInitialized(src)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("storage file backend not initialized")); + return NULL; + } + + if (!src->drv->backend->storageFileGetUniqueIdentifier) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("unique storage file identifier not implemented for " + "storage type %s (protocol: %s)'"), + virStorageTypeToString(src->type), + virStorageNetProtocolTypeToString(src->protocol)); + return NULL; + } + + return src->drv->backend->storageFileGetUniqueIdentifier(src); +} diff --git a/src/storage/storage_driver.h b/src/storage/storage_driver.h index d67d74b..9280ef0 100644 --- a/src/storage/storage_driver.h +++ b/src/storage/storage_driver.h @@ -41,6 +41,7 @@ int virStorageFileStat(virStorageSourcePtr src, ssize_t virStorageFileReadHeader(virStorageSourcePtr src, ssize_t max_len, char **buf); +const char *virStorageFileGetUniqueIdentifier(virStorageSourcePtr src); int storageRegister(void); -- 1.9.3

Add a storage driver API equivalent ot the access() function. Implementations for the filesystem and gluster backends are provided. --- src/storage/storage_backend.h | 5 +++++ src/storage/storage_backend_fs.c | 13 +++++++++++++ src/storage/storage_backend_gluster.c | 11 +++++++++++ src/storage/storage_driver.c | 24 ++++++++++++++++++++++++ src/storage/storage_driver.h | 1 + 5 files changed, 54 insertions(+) diff --git a/src/storage/storage_backend.h b/src/storage/storage_backend.h index 5d71cde..56643fb 100644 --- a/src/storage/storage_backend.h +++ b/src/storage/storage_backend.h @@ -198,6 +198,10 @@ typedef ssize_t typedef const char * (*virStorageFileBackendGetUniqueIdentifier)(virStorageSourcePtr src); +typedef int +(*virStorageFileBackendAccess)(virStorageSourcePtr src, + int mode); + virStorageFileBackendPtr virStorageFileBackendForType(int type, int protocol); @@ -220,6 +224,7 @@ struct _virStorageFileBackend { virStorageFileBackendCreate storageFileCreate; virStorageFileBackendUnlink storageFileUnlink; virStorageFileBackendStat storageFileStat; + virStorageFileBackendAccess storageFileAccess; }; #endif /* __VIR_STORAGE_BACKEND_H__ */ diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c index 1f436fa..85264a7 100644 --- a/src/storage/storage_backend_fs.c +++ b/src/storage/storage_backend_fs.c @@ -1439,6 +1439,15 @@ virStorageFileBackendFileGetUniqueIdentifier(virStorageSourcePtr src) } +static int +virStorageFileBackendFileAccess(virStorageSourcePtr src, + int mode) +{ + return virFileAccessibleAs(src->path, mode, + src->drv->uid, src->drv->gid); +} + + virStorageFileBackend virStorageFileBackendFile = { .type = VIR_STORAGE_TYPE_FILE, @@ -1448,6 +1457,7 @@ virStorageFileBackend virStorageFileBackendFile = { .storageFileUnlink = virStorageFileBackendFileUnlink, .storageFileStat = virStorageFileBackendFileStat, .storageFileReadHeader = virStorageFileBackendFileReadHeader, + .storageFileAccess = virStorageFileBackendFileAccess, .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, }; @@ -1461,6 +1471,7 @@ virStorageFileBackend virStorageFileBackendBlock = { .storageFileStat = virStorageFileBackendFileStat, .storageFileReadHeader = virStorageFileBackendFileReadHeader, + .storageFileAccess = virStorageFileBackendFileAccess, .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, }; @@ -1472,6 +1483,8 @@ virStorageFileBackend virStorageFileBackendDir = { .backendInit = virStorageFileBackendFileInit, .backendDeinit = virStorageFileBackendFileDeinit, + .storageFileAccess = virStorageFileBackendFileAccess, + .storageFileGetUniqueIdentifier = virStorageFileBackendFileGetUniqueIdentifier, }; diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c index badffae..1a844c9 100644 --- a/src/storage/storage_backend_gluster.c +++ b/src/storage/storage_backend_gluster.c @@ -703,6 +703,16 @@ virStorageFileBackendGlusterReadHeader(virStorageSourcePtr src, } +static int +virStorageFileBackendGlusterAccess(virStorageSourcePtr src, + int mode) +{ + virStorageFileBackendGlusterPrivPtr priv = src->drv->priv; + + return glfs_access(priv->vol, src->path, mode); +} + + virStorageFileBackend virStorageFileBackendGluster = { .type = VIR_STORAGE_TYPE_NETWORK, .protocol = VIR_STORAGE_NET_PROTOCOL_GLUSTER, @@ -713,4 +723,5 @@ virStorageFileBackend virStorageFileBackendGluster = { .storageFileUnlink = virStorageFileBackendGlusterUnlink, .storageFileStat = virStorageFileBackendGlusterStat, .storageFileReadHeader = virStorageFileBackendGlusterReadHeader, + .storageFileAccess = virStorageFileBackendGlusterAccess, }; diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 2036bfd..cb660ea 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -3017,3 +3017,27 @@ virStorageFileGetUniqueIdentifier(virStorageSourcePtr src) return src->drv->backend->storageFileGetUniqueIdentifier(src); } + + +/** + * virStorageFileAccess: Check accessability of a storage file + * + * @src: storage file to check access permissions + * @mode: accessibility check options (see man 2 access) + * + * Returns 0 on success, -1 on error and sets errno. No libvirt + * error is reported. Returns -2 if the operation isn't supported + * by libvirt storage backend. + */ +int +virStorageFileAccess(virStorageSourcePtr src, + int mode) +{ + if (!virStorageFileIsInitialized(src) || + !src->drv->backend->storageFileAccess) { + errno = ENOSYS; + return -2; + } + + return src->drv->backend->storageFileAccess(src, mode); +} diff --git a/src/storage/storage_driver.h b/src/storage/storage_driver.h index 9280ef0..5452df2 100644 --- a/src/storage/storage_driver.h +++ b/src/storage/storage_driver.h @@ -42,6 +42,7 @@ ssize_t virStorageFileReadHeader(virStorageSourcePtr src, ssize_t max_len, char **buf); const char *virStorageFileGetUniqueIdentifier(virStorageSourcePtr src); +int virStorageFileAccess(virStorageSourcePtr src, int mode); int storageRegister(void); -- 1.9.3

My future work will modify the metadata crawler function to use the storage driver file APIs to access the files instead of accessing them directly so that we will be able to request the metadata for remote files too. To avoid linking the storage driver to every helper file using the utils code, the backing chain traversal function needs to be moved to the storage driver source. Additionally the virt-aa-helper and virstoragetest programs need to be linked with the storage driver as a result of this change. --- cfg.mk | 2 +- src/Makefile.am | 2 + src/libvirt_private.syms | 2 +- src/qemu/qemu_domain.c | 2 + src/security/virt-aa-helper.c | 2 + src/storage/storage_driver.c | 233 ++++++++++++++++++++++++++++++++++++++++++ src/storage/storage_driver.h | 5 + src/util/virstoragefile.c | 233 +----------------------------------------- src/util/virstoragefile.h | 7 +- tests/Makefile.am | 7 +- tests/virstoragetest.c | 2 + 11 files changed, 258 insertions(+), 239 deletions(-) diff --git a/cfg.mk b/cfg.mk index 5ff2721..9e8fcec 100644 --- a/cfg.mk +++ b/cfg.mk @@ -774,7 +774,7 @@ sc_prohibit_cross_inclusion: access/ | conf/) safe="($$dir|conf|util)";; \ locking/) safe="($$dir|util|conf|rpc)";; \ cpu/| network/| node_device/| rpc/| security/| storage/) \ - safe="($$dir|util|conf)";; \ + safe="($$dir|util|conf|storage)";; \ xenapi/ | xenxs/ ) safe="($$dir|util|conf|xen)";; \ *) safe="($$dir|$(mid_dirs)|util)";; \ esac; \ diff --git a/src/Makefile.am b/src/Makefile.am index cfb7097..5028f0d 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -2565,8 +2565,10 @@ virt_aa_helper_LDFLAGS = \ $(PIE_LDFLAGS) \ $(NULL) virt_aa_helper_LDADD = \ + libvirt.la \ libvirt_conf.la \ libvirt_util.la \ + libvirt_driver_storage_impl.la \ ../gnulib/lib/libgnu.la if WITH_DTRACE_PROBES virt_aa_helper_LDADD += libvirt_probes.lo diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index c3332c9..25dab2d 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1863,9 +1863,9 @@ virStorageFileFeatureTypeToString; virStorageFileFormatTypeFromString; virStorageFileFormatTypeToString; virStorageFileGetLVMKey; -virStorageFileGetMetadata; virStorageFileGetMetadataFromBuf; virStorageFileGetMetadataFromFD; +virStorageFileGetMetadataFromFDInternal; virStorageFileGetSCSIKey; virStorageFileIsClusterFS; virStorageFileParseChainIndex; diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 78cfdc6..502b7bd 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -40,6 +40,8 @@ #include "virstoragefile.h" #include "virstring.h" +#include "storage/storage_driver.h" + #include <sys/time.h> #include <fcntl.h> diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 32fc04a..bf540b4 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -55,6 +55,8 @@ #include "virrandom.h" #include "virstring.h" +#include "storage/storage_driver.h" + #define VIR_FROM_THIS VIR_FROM_SECURITY static char *progname; diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index cb660ea..c90107b 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -49,6 +49,7 @@ #include "configmake.h" #include "virstring.h" #include "viraccessapicheck.h" +#include "dirname.h" #define VIR_FROM_THIS VIR_FROM_STORAGE @@ -3041,3 +3042,235 @@ virStorageFileAccess(virStorageSourcePtr src, return src->drv->backend->storageFileAccess(src, mode); } + + +/** + * Given a starting point START (a directory containing the original + * file, if the original file was opened via a relative path; ignored + * if NAME is absolute), determine the location of the backing file + * NAME (possibly relative), and compute the relative DIRECTORY + * (optional) and CANONICAL (mandatory) location of the backing file. + * Return 0 on success, negative on error. + */ +static int ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4) +virFindBackingFile(const char *start, const char *path, + char **directory, char **canonical) +{ + /* FIXME - when we eventually allow non-raw network devices, we + * must ensure that we handle backing files the same way as qemu. + * For a qcow2 top file of gluster://server/vol/img, qemu treats + * the relative backing file 'rel' as meaning + * 'gluster://server/vol/rel', while the backing file '/abs' is + * used as a local file. But we cannot canonicalize network + * devices via canonicalize_file_name(), because they are not part + * of the local file system. */ + char *combined = NULL; + int ret = -1; + + if (*path == '/') { + /* Safe to cast away const */ + combined = (char *)path; + } else if (virAsprintf(&combined, "%s/%s", start, path) < 0) { + goto cleanup; + } + + if (directory && !(*directory = mdir_name(combined))) { + virReportOOMError(); + goto cleanup; + } + + if (virFileAccessibleAs(combined, F_OK, geteuid(), getegid()) < 0) { + virReportSystemError(errno, + _("Cannot access backing file '%s'"), + combined); + goto cleanup; + } + + if (!(*canonical = canonicalize_file_name(combined))) { + virReportSystemError(errno, + _("Can't canonicalize path '%s'"), path); + goto cleanup; + } + + ret = 0; + + cleanup: + if (combined != path) + VIR_FREE(combined); + return ret; +} + + +/* Recursive workhorse for virStorageFileGetMetadata. */ +static int +virStorageFileGetMetadataRecurse(virStorageSourcePtr src, + const char *canonPath, + uid_t uid, gid_t gid, + bool allow_probe, + virHashTablePtr cycle) +{ + int fd; + int ret = -1; + virStorageSourcePtr backingStore = NULL; + int backingFormat; + + VIR_DEBUG("path=%s canonPath=%s dir=%s format=%d uid=%d gid=%d probe=%d", + src->path, canonPath, NULLSTR(src->relDir), src->format, + (int)uid, (int)gid, allow_probe); + + if (virHashLookup(cycle, canonPath)) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("backing store for %s is self-referential"), + src->path); + return -1; + } + + if (virHashAddEntry(cycle, canonPath, (void *)1) < 0) + return -1; + + if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK) { + if ((fd = virFileOpenAs(src->path, O_RDONLY, 0, uid, gid, 0)) < 0) { + virReportSystemError(-fd, _("Failed to open file '%s'"), + src->path); + return -1; + } + + if (virStorageFileGetMetadataFromFDInternal(src, fd, + &backingFormat) < 0) { + VIR_FORCE_CLOSE(fd); + return -1; + } + + if (VIR_CLOSE(fd) < 0) + VIR_WARN("could not close file %s", src->path); + } else { + /* TODO: currently we call this only for local storage */ + return 0; + } + + /* check whether we need to go deeper */ + if (!src->backingStoreRaw) + return 0; + + if (VIR_ALLOC(backingStore) < 0) + return -1; + + if (VIR_STRDUP(backingStore->relPath, src->backingStoreRaw) < 0) + goto cleanup; + + if (virStorageIsFile(src->backingStoreRaw)) { + backingStore->type = VIR_STORAGE_TYPE_FILE; + + if (virFindBackingFile(src->relDir, + src->backingStoreRaw, + &backingStore->relDir, + &backingStore->path) < 0) { + /* the backing file is (currently) unavailable, treat this + * file as standalone: + * backingStoreRaw is kept to mark broken image chains */ + VIR_WARN("Backing file '%s' of image '%s' is missing.", + src->backingStoreRaw, src->path); + ret = 0; + goto cleanup; + } + } else { + /* TODO: To satisfy the test case, copy the network URI as path. This + * will be removed later. */ + backingStore->type = VIR_STORAGE_TYPE_NETWORK; + + if (VIR_STRDUP(backingStore->path, src->backingStoreRaw) < 0) + goto cleanup; + } + + if (backingFormat == VIR_STORAGE_FILE_AUTO && !allow_probe) + backingStore->format = VIR_STORAGE_FILE_RAW; + else if (backingFormat == VIR_STORAGE_FILE_AUTO_SAFE) + backingStore->format = VIR_STORAGE_FILE_AUTO; + else + backingStore->format = backingFormat; + + if (virStorageFileGetMetadataRecurse(backingStore, + backingStore->path, + uid, gid, allow_probe, + cycle) < 0) { + /* if we fail somewhere midway, just accept and return a + * broken chain */ + ret = 0; + goto cleanup; + } + + src->backingStore = backingStore; + backingStore = NULL; + ret = 0; + + cleanup: + virStorageSourceFree(backingStore); + return ret; +} + + +/** + * virStorageFileGetMetadata: + * + * Extract metadata about the storage volume with the specified + * image format. If image format is VIR_STORAGE_FILE_AUTO, it + * will probe to automatically identify the format. Recurses through + * the entire chain. + * + * Open files using UID and GID (or pass -1 for the current user/group). + * Treat any backing files without explicit type as raw, unless ALLOW_PROBE. + * + * Callers are advised never to use VIR_STORAGE_FILE_AUTO as a + * format, since a malicious guest can turn a raw file into any + * other non-raw format at will. + * + * Caller MUST free result after use via virStorageSourceFree. + */ +int +virStorageFileGetMetadata(virStorageSourcePtr src, + uid_t uid, gid_t gid, + bool allow_probe) +{ + VIR_DEBUG("path=%s format=%d uid=%d gid=%d probe=%d", + src->path, src->format, (int)uid, (int)gid, allow_probe); + + virHashTablePtr cycle = NULL; + char *canonPath = NULL; + int ret = -1; + + if (!(cycle = virHashCreate(5, NULL))) + return -1; + + if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK) { + if (!(canonPath = canonicalize_file_name(src->path))) { + virReportSystemError(errno, _("unable to resolve '%s'"), + src->path); + goto cleanup; + } + + if (!src->relPath && + VIR_STRDUP(src->relPath, src->path) < 0) + goto cleanup; + + if (!src->relDir && + !(src->relDir = mdir_name(src->path))) { + virReportOOMError(); + goto cleanup; + } + } else { + /* TODO: currently unimplemented for non-local storage */ + ret = 0; + goto cleanup; + } + + if (src->format <= VIR_STORAGE_FILE_NONE) + src->format = allow_probe ? VIR_STORAGE_FILE_AUTO : VIR_STORAGE_FILE_RAW; + + ret = virStorageFileGetMetadataRecurse(src, canonPath, uid, gid, + allow_probe, cycle); + + cleanup: + VIR_FREE(canonPath); + virHashFree(cycle); + return ret; +} diff --git a/src/storage/storage_driver.h b/src/storage/storage_driver.h index 5452df2..bd9e9ed 100644 --- a/src/storage/storage_driver.h +++ b/src/storage/storage_driver.h @@ -44,6 +44,11 @@ ssize_t virStorageFileReadHeader(virStorageSourcePtr src, const char *virStorageFileGetUniqueIdentifier(virStorageSourcePtr src); int virStorageFileAccess(virStorageSourcePtr src, int mode); +int virStorageFileGetMetadata(virStorageSourcePtr src, + uid_t uid, gid_t gid, + bool allow_probe) + ATTRIBUTE_NONNULL(1); + int storageRegister(void); #endif /* __VIR_STORAGE_DRIVER_H__ */ diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index b90cdc9..06bb68c 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -28,7 +28,6 @@ #include <unistd.h> #include <fcntl.h> #include <stdlib.h> -#include "dirname.h" #include "viralloc.h" #include "virerror.h" #include "virlog.h" @@ -565,62 +564,6 @@ qedGetBackingStore(char **res, return BACKING_STORE_OK; } -/** - * Given a starting point START (a directory containing the original - * file, if the original file was opened via a relative path; ignored - * if NAME is absolute), determine the location of the backing file - * NAME (possibly relative), and compute the relative DIRECTORY - * (optional) and CANONICAL (mandatory) location of the backing file. - * Return 0 on success, negative on error. - */ -static int ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4) -virFindBackingFile(const char *start, const char *path, - char **directory, char **canonical) -{ - /* FIXME - when we eventually allow non-raw network devices, we - * must ensure that we handle backing files the same way as qemu. - * For a qcow2 top file of gluster://server/vol/img, qemu treats - * the relative backing file 'rel' as meaning - * 'gluster://server/vol/rel', while the backing file '/abs' is - * used as a local file. But we cannot canonicalize network - * devices via canonicalize_file_name(), because they are not part - * of the local file system. */ - char *combined = NULL; - int ret = -1; - - if (*path == '/') { - /* Safe to cast away const */ - combined = (char *)path; - } else if (virAsprintf(&combined, "%s/%s", start, path) < 0) { - goto cleanup; - } - - if (directory && !(*directory = mdir_name(combined))) { - virReportOOMError(); - goto cleanup; - } - - if (virFileAccessibleAs(combined, F_OK, geteuid(), getegid()) < 0) { - virReportSystemError(errno, - _("Cannot access backing file '%s'"), - combined); - goto cleanup; - } - - if (!(*canonical = canonicalize_file_name(combined))) { - virReportSystemError(errno, - _("Can't canonicalize path '%s'"), path); - goto cleanup; - } - - ret = 0; - - cleanup: - if (combined != path) - VIR_FREE(combined); - return ret; -} - static bool virStorageFileMatchesMagic(int format, @@ -1019,7 +962,7 @@ virStorageFileGetMetadataFromBuf(const char *path, /* Internal version that also supports a containing directory name. */ -static int +int virStorageFileGetMetadataFromFDInternal(virStorageSourcePtr meta, int fd, int *backingFormat) @@ -1108,180 +1051,6 @@ virStorageFileGetMetadataFromFD(const char *path, } -/* Recursive workhorse for virStorageFileGetMetadata. */ -static int -virStorageFileGetMetadataRecurse(virStorageSourcePtr src, - const char *canonPath, - uid_t uid, gid_t gid, - bool allow_probe, - virHashTablePtr cycle) -{ - int fd; - int ret = -1; - virStorageSourcePtr backingStore = NULL; - int backingFormat; - - VIR_DEBUG("path=%s canonPath=%s dir=%s format=%d uid=%d gid=%d probe=%d", - src->path, canonPath, NULLSTR(src->relDir), src->format, - (int)uid, (int)gid, allow_probe); - - if (virHashLookup(cycle, canonPath)) { - virReportError(VIR_ERR_INTERNAL_ERROR, - _("backing store for %s is self-referential"), - src->path); - return -1; - } - - if (virHashAddEntry(cycle, canonPath, (void *)1) < 0) - return -1; - - if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK) { - if ((fd = virFileOpenAs(src->path, O_RDONLY, 0, uid, gid, 0)) < 0) { - virReportSystemError(-fd, _("Failed to open file '%s'"), - src->path); - return -1; - } - - if (virStorageFileGetMetadataFromFDInternal(src, fd, - &backingFormat) < 0) { - VIR_FORCE_CLOSE(fd); - return -1; - } - - if (VIR_CLOSE(fd) < 0) - VIR_WARN("could not close file %s", src->path); - } else { - /* TODO: currently we call this only for local storage */ - return 0; - } - - /* check whether we need to go deeper */ - if (!src->backingStoreRaw) - return 0; - - if (VIR_ALLOC(backingStore) < 0) - return -1; - - if (VIR_STRDUP(backingStore->relPath, src->backingStoreRaw) < 0) - goto cleanup; - - if (virStorageIsFile(src->backingStoreRaw)) { - backingStore->type = VIR_STORAGE_TYPE_FILE; - - if (virFindBackingFile(src->relDir, - src->backingStoreRaw, - &backingStore->relDir, - &backingStore->path) < 0) { - /* the backing file is (currently) unavailable, treat this - * file as standalone: - * backingStoreRaw is kept to mark broken image chains */ - VIR_WARN("Backing file '%s' of image '%s' is missing.", - src->backingStoreRaw, src->path); - ret = 0; - goto cleanup; - } - } else { - /* TODO: To satisfy the test case, copy the network URI as path. This - * will be removed later. */ - backingStore->type = VIR_STORAGE_TYPE_NETWORK; - - if (VIR_STRDUP(backingStore->path, src->backingStoreRaw) < 0) - goto cleanup; - } - - if (backingFormat == VIR_STORAGE_FILE_AUTO && !allow_probe) - backingStore->format = VIR_STORAGE_FILE_RAW; - else if (backingFormat == VIR_STORAGE_FILE_AUTO_SAFE) - backingStore->format = VIR_STORAGE_FILE_AUTO; - else - backingStore->format = backingFormat; - - if (virStorageFileGetMetadataRecurse(backingStore, - backingStore->path, - uid, gid, allow_probe, - cycle) < 0) { - /* if we fail somewhere midway, just accept and return a - * broken chain */ - ret = 0; - goto cleanup; - } - - src->backingStore = backingStore; - backingStore = NULL; - ret = 0; - - cleanup: - virStorageSourceFree(backingStore); - return ret; -} - - -/** - * virStorageFileGetMetadata: - * - * Extract metadata about the storage volume with the specified - * image format. If image format is VIR_STORAGE_FILE_AUTO, it - * will probe to automatically identify the format. Recurses through - * the entire chain. - * - * Open files using UID and GID (or pass -1 for the current user/group). - * Treat any backing files without explicit type as raw, unless ALLOW_PROBE. - * - * Callers are advised never to use VIR_STORAGE_FILE_AUTO as a - * format, since a malicious guest can turn a raw file into any - * other non-raw format at will. - * - * Caller MUST free result after use via virStorageSourceFree. - */ -int -virStorageFileGetMetadata(virStorageSourcePtr src, - uid_t uid, gid_t gid, - bool allow_probe) -{ - VIR_DEBUG("path=%s format=%d uid=%d gid=%d probe=%d", - src->path, src->format, (int)uid, (int)gid, allow_probe); - - virHashTablePtr cycle = NULL; - char *canonPath = NULL; - int ret = -1; - - if (!(cycle = virHashCreate(5, NULL))) - return -1; - - if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK) { - if (!(canonPath = canonicalize_file_name(src->path))) { - virReportSystemError(errno, _("unable to resolve '%s'"), - src->path); - goto cleanup; - } - - if (!src->relPath && - VIR_STRDUP(src->relPath, src->path) < 0) - goto cleanup; - - if (!src->relDir && - !(src->relDir = mdir_name(src->path))) { - virReportOOMError(); - goto cleanup; - } - } else { - /* TODO: currently unimplemented for non-local storage */ - ret = 0; - goto cleanup; - } - - if (src->format <= VIR_STORAGE_FILE_NONE) - src->format = allow_probe ? VIR_STORAGE_FILE_AUTO : VIR_STORAGE_FILE_RAW; - - ret = virStorageFileGetMetadataRecurse(src, canonPath, uid, gid, - allow_probe, cycle); - - cleanup: - VIR_FREE(canonPath); - virHashFree(cycle); - return ret; -} - /** * virStorageFileChainCheckBroken * diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h index 082ff5b..c1babdc 100644 --- a/src/util/virstoragefile.h +++ b/src/util/virstoragefile.h @@ -265,10 +265,9 @@ struct _virStorageSource { int virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid); -int virStorageFileGetMetadata(virStorageSourcePtr src, - uid_t uid, gid_t gid, - bool allow_probe) - ATTRIBUTE_NONNULL(1); +int virStorageFileGetMetadataFromFDInternal(virStorageSourcePtr meta, + int fd, + int *backingFormat); virStorageSourcePtr virStorageFileGetMetadataFromFD(const char *path, int fd, int format); diff --git a/tests/Makefile.am b/tests/Makefile.am index 5ef8940..4d24822 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -869,7 +869,12 @@ virstringtest_LDADD = $(LDADDS) virstoragetest_SOURCES = \ virstoragetest.c testutils.h testutils.c -virstoragetest_LDADD = $(LDADDS) +virstoragetest_LDADD = $(LDADDS) \ + ../src/libvirt.la \ + ../src/libvirt_conf.la \ + ../src/libvirt_util.la \ + ../src/libvirt_driver_storage_impl.la \ + ../gnulib/lib/libgnu.la viridentitytest_SOURCES = \ viridentitytest.c testutils.h testutils.c diff --git a/tests/virstoragetest.c b/tests/virstoragetest.c index d49098e..fb96c71 100644 --- a/tests/virstoragetest.c +++ b/tests/virstoragetest.c @@ -31,6 +31,8 @@ #include "virstring.h" #include "dirname.h" +#include "storage/storage_driver.h" + #define VIR_FROM_THIS VIR_FROM_NONE VIR_LOG_INIT("tests.storagetest"); -- 1.9.3

On 05/22/2014 07:47 AM, Peter Krempa wrote: Does this add additional stat() calls to the loop, which could be optimized by including a struct stat in virStorageSource and reusing that data when already obtained earlier? At any rate, cleaning that up to minimize stat calls should be a separate patch, so this one is fine. ACK. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org

Stat the path of the storage file being tested to set the correct type into the virStorageSource. This will avoid breaking the test suite when inquiring metadata of directory paths in the next patches. --- tests/virstoragetest.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tests/virstoragetest.c b/tests/virstoragetest.c index fb96c71..746bf63 100644 --- a/tests/virstoragetest.c +++ b/tests/virstoragetest.c @@ -98,6 +98,7 @@ testStorageFileGetMetadata(const char *path, uid_t uid, gid_t gid, bool allow_probe) { + struct stat st; virStorageSourcePtr ret = NULL; if (VIR_ALLOC(ret) < 0) @@ -106,6 +107,15 @@ testStorageFileGetMetadata(const char *path, ret->type = VIR_STORAGE_TYPE_FILE; ret->format = format; + if (stat(path, &st) == 0) { + if (S_ISDIR(st.st_mode)) { + ret->type = VIR_STORAGE_TYPE_DIR; + ret->format = VIR_STORAGE_FILE_DIR; + } else if (S_ISBLK(st.st_mode)) { + ret->type = VIR_STORAGE_TYPE_BLOCK; + } + } + if (VIR_STRDUP(ret->relPath, path) < 0) goto error; -- 1.9.3

On 05/23/14 19:29, Eric Blake wrote: Not in this case. This code here is used to set the correct type of the file prior to the first iteration of the loop in the tests. The test code doesn't initialize the type of the volume to the actual type (for directories) so we need to fix it up before iterating. Otherwise the test would fail in the later patches as it would try to access a directory as a file. This argument would be relevant in the previous patch. Here in the test code there is no possible race. Peter

Use the new backing store parser in the backing chain crawler. This change needs one test change where information about the NBD image are now parsed differently. --- src/storage/storage_driver.c | 90 +------------------------------------------- tests/virstoragetest.c | 14 ++++--- 2 files changed, 9 insertions(+), 95 deletions(-) diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 67882ce..a4518cb 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -3068,56 +3068,6 @@ virStorageFileAccess(virStorageSourcePtr src, } -/** - * Given a starting point START (a directory containing the original - * file, if the original file was opened via a relative path; ignored - * if NAME is absolute), determine the location of the backing file - * NAME (possibly relative), and compute the relative DIRECTORY - * (optional) and CANONICAL (mandatory) location of the backing file. - * Return 0 on success, negative on error. - */ -static int ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4) -virFindBackingFile(const char *start, const char *path, - char **directory, char **canonical) -{ - /* FIXME - when we eventually allow non-raw network devices, we - * must ensure that we handle backing files the same way as qemu. - * For a qcow2 top file of gluster://server/vol/img, qemu treats - * the relative backing file 'rel' as meaning - * 'gluster://server/vol/rel', while the backing file '/abs' is - * used as a local file. But we cannot canonicalize network - * devices via canonicalize_file_name(), because they are not part - * of the local file system. */ - char *combined = NULL; - int ret = -1; - - if (*path == '/') { - /* Safe to cast away const */ - combined = (char *)path; - } else if (virAsprintf(&combined, "%s/%s", start, path) < 0) { - goto cleanup; - } - - if (directory && !(*directory = mdir_name(combined))) { - virReportOOMError(); - goto cleanup; - } - - if (!(*canonical = canonicalize_file_name(combined))) { - virReportSystemError(errno, - _("Can't canonicalize path '%s'"), path); - goto cleanup; - } - - ret = 0; - - cleanup: - if (combined != path) - VIR_FREE(combined); - return ret; -} - - /* Recursive workhorse for virStorageFileGetMetadata. */ static int virStorageFileGetMetadataRecurse(virStorageSourcePtr src, @@ -3126,7 +3076,6 @@ virStorageFileGetMetadataRecurse(virStorageSourcePtr src, virHashTablePtr cycle) { int ret = -1; - struct stat st; const char *uniqueName; char *buf = NULL; ssize_t headerLen; @@ -3178,46 +3127,9 @@ virStorageFileGetMetadataRecurse(virStorageSourcePtr src, goto cleanup; } - if (VIR_ALLOC(backingStore) < 0) + if (!(backingStore = virStorageSourceNewFromBacking(src))) goto cleanup; - if (VIR_STRDUP(backingStore->relPath, src->backingStoreRaw) < 0) - goto cleanup; - - if (virStorageIsFile(src->backingStoreRaw)) { - backingStore->type = VIR_STORAGE_TYPE_FILE; - - if (virFindBackingFile(src->relDir, - src->backingStoreRaw, - &backingStore->relDir, - &backingStore->path) < 0) { - /* the backing file is (currently) unavailable, treat this - * file as standalone: - * backingStoreRaw is kept to mark broken image chains */ - VIR_WARN("Backing file '%s' of image '%s' is missing.", - src->backingStoreRaw, src->path); - ret = 0; - goto cleanup; - } - - /* update the type for local storage */ - if (stat(backingStore->path, &st) == 0) { - if (S_ISDIR(st.st_mode)) { - backingStore->type = VIR_STORAGE_TYPE_DIR; - backingStore->format = VIR_STORAGE_FILE_DIR; - } else if (S_ISBLK(st.st_mode)) { - backingStore->type = VIR_STORAGE_TYPE_BLOCK; - } - } - } else { - /* TODO: To satisfy the test case, copy the network URI as path. This - * will be removed later. */ - backingStore->type = VIR_STORAGE_TYPE_NETWORK; - - if (VIR_STRDUP(backingStore->path, src->backingStoreRaw) < 0) - goto cleanup; - } - if (backingFormat == VIR_STORAGE_FILE_AUTO && !allow_probe) backingStore->format = VIR_STORAGE_FILE_RAW; else if (backingFormat == VIR_STORAGE_FILE_AUTO_SAFE) diff --git a/tests/virstoragetest.c b/tests/virstoragetest.c index 746bf63..29297ef 100644 --- a/tests/virstoragetest.c +++ b/tests/virstoragetest.c @@ -730,20 +730,22 @@ mymain(void) /* Rewrite qcow2 to use an nbd: protocol as backend */ virCommandFree(cmd); cmd = virCommandNewArgList(qemuimg, "rebase", "-u", "-f", "qcow2", - "-F", "raw", "-b", "nbd:example.org:6000", + "-F", "raw", "-b", "nbd:example.org:6000:exportname=blah", "qcow2", NULL); if (virCommandRun(cmd, NULL) < 0) ret = -1; - qcow2.expBackingStore = "nbd:example.org:6000"; - qcow2.expBackingStoreRaw = "nbd:example.org:6000"; + qcow2.expBackingStore = "blah"; + qcow2.expBackingStoreRaw = "nbd:example.org:6000:exportname=blah"; /* Qcow2 file with backing protocol instead of file */ testFileData nbd = { - .pathRel = "nbd:example.org:6000", - .pathAbs = "nbd:example.org:6000", - .path = "nbd:example.org:6000", + .pathRel = "nbd:example.org:6000:exportname=blah", + .pathAbs = "nbd:example.org:6000:exportname=blah", + .path = "blah", .type = VIR_STORAGE_TYPE_NETWORK, .format = VIR_STORAGE_FILE_RAW, + .relDirRel = ".", + .relDirAbs = ".", }; TEST_CHAIN(11, "qcow2", absqcow2, VIR_STORAGE_FILE_QCOW2, (&qcow2, &nbd), EXP_PASS, -- 1.9.3

To allow using the array manipulation macros on the arrays returned by virStringSplit we need to know the count of the elements in the array. Modify virStringSplit to return this value, rename it and add a helper with the old name so that we don't need to update all the code. --- src/libvirt_private.syms | 1 + src/util/virstring.c | 24 ++++++++++++++++++++---- src/util/virstring.h | 6 ++++++ 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 2b2bc10..ee745ea 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1908,6 +1908,7 @@ virStringSearch; virStringSortCompare; virStringSortRevCompare; virStringSplit; +virStringSplitCount; virStrncpy; virStrndup; virStrToDouble; diff --git a/src/util/virstring.c b/src/util/virstring.c index 7a8430e..6dcc7a8 100644 --- a/src/util/virstring.c +++ b/src/util/virstring.c @@ -43,13 +43,15 @@ VIR_LOG_INIT("util.string"); */ /** - * virStringSplit: + * virStringSplitCount: * @string: a string to split * @delim: a string which specifies the places at which to split * the string. The delimiter is not included in any of the resulting * strings, unless @max_tokens is reached. * @max_tokens: the maximum number of pieces to split @string into. * If this is 0, the string is split completely. + * @tokcount: If provided, the value is set to the count of pieces the string + * was split to excluding the terminating NULL element. * * Splits a string into a maximum of @max_tokens pieces, using the given * @delim. If @max_tokens is reached, the remainder of @string is @@ -65,9 +67,11 @@ VIR_LOG_INIT("util.string"); * Return value: a newly-allocated NULL-terminated array of strings. Use * virStringFreeList() to free it. */ -char **virStringSplit(const char *string, - const char *delim, - size_t max_tokens) +char ** +virStringSplitCount(const char *string, + const char *delim, + size_t max_tokens, + size_t *tokcount) { char **tokens = NULL; size_t ntokens = 0; @@ -109,6 +113,9 @@ char **virStringSplit(const char *string, goto error; tokens[ntokens++] = NULL; + if (tokcount) + *tokcount = ntokens - 1; + return tokens; error: @@ -119,6 +126,15 @@ char **virStringSplit(const char *string, } +char ** +virStringSplit(const char *string, + const char *delim, + size_t max_tokens) +{ + return virStringSplitCount(string, delim, max_tokens, NULL); +} + + /** * virStringJoin: * @strings: a NULL-terminated array of strings to join diff --git a/src/util/virstring.h b/src/util/virstring.h index 1ed1046..0ab9d96 100644 --- a/src/util/virstring.h +++ b/src/util/virstring.h @@ -26,6 +26,12 @@ # include "internal.h" +char **virStringSplitCount(const char *string, + const char *delim, + size_t max_tokens, + size_t *tokcount) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2); + char **virStringSplit(const char *string, const char *delim, size_t max_tokens) -- 1.9.3

Sometimes the length of the string list is known but the array isn't NULL terminated. Add helper to free the array in such cases. --- src/libvirt_private.syms | 1 + src/util/virstring.c | 20 ++++++++++++++++++++ src/util/virstring.h | 1 + 3 files changed, 22 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index ee745ea..cb1fd72 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1901,6 +1901,7 @@ virStrcpy; virStrdup; virStringArrayHasString; virStringFreeList; +virStringFreeListCount; virStringJoin; virStringListLength; virStringReplace; diff --git a/src/util/virstring.c b/src/util/virstring.c index 6dcc7a8..35b99a5 100644 --- a/src/util/virstring.c +++ b/src/util/virstring.c @@ -187,6 +187,26 @@ void virStringFreeList(char **strings) } +/** + * virStringFreeListCount: + * @strings: array of strings to free + * @count: number of elements in the array + * + * Frees a string array of @count length. + */ +void +virStringFreeListCount(char **strings, + size_t count) +{ + size_t i; + + for (i = 0; i < count; i++) + VIR_FREE(strings[i]); + + VIR_FREE(strings); +} + + bool virStringArrayHasString(char **strings, const char *needle) { diff --git a/src/util/virstring.h b/src/util/virstring.h index 0ab9d96..42d68b5 100644 --- a/src/util/virstring.h +++ b/src/util/virstring.h @@ -42,6 +42,7 @@ char *virStringJoin(const char **strings, ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2); void virStringFreeList(char **strings); +void virStringFreeListCount(char **strings, size_t count); bool virStringArrayHasString(char **strings, const char *needle); -- 1.9.3

This patch introduces a function that will allow us to resolve a relative difference between two elements of a disk backing chain. This fucntion will be used to allow relative block commit and block pull where we need to specify the new relative name of the image to qemu. This patch also adds unit tests for the function to verify that it works correctly. --- src/libvirt_private.syms | 1 + src/util/virstoragefile.c | 45 +++++++++++++++++++++ src/util/virstoragefile.h | 4 ++ tests/virstoragetest.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 151 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index cb1fd72..6787b51 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1866,6 +1866,7 @@ virStorageFileGetLVMKey; virStorageFileGetMetadataFromBuf; virStorageFileGetMetadataFromFD; virStorageFileGetMetadataInternal; +virStorageFileGetRelativeBackingPath; virStorageFileGetSCSIKey; virStorageFileIsClusterFS; virStorageFileParseChainIndex; diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index 21d71c4..a390b1c 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -2019,3 +2019,48 @@ virStorageFileSimplifyPath(const char *path, return ret; } + + +int +virStorageFileGetRelativeBackingPath(virStorageSourcePtr from, + virStorageSourcePtr to, + char **relpath) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + virStorageSourcePtr next; + char *tmp = NULL; + char ret = -1; + + *relpath = NULL; + + for (next = from; next; next = next->backingStore) { + if (!next->backingRelative || !next->relPath) { + ret = 1; + goto cleanup; + } + + if (next != from) + virBufferAddLit(&buf, "/../"); + + virBufferAdd(&buf, next->relPath, -1); + + if (next == to) + break; + } + + if (next != to) + goto cleanup; + + if (!(tmp = virBufferContentAndReset(&buf))) + goto cleanup; + + if (!(*relpath = virStorageFileSimplifyPath(tmp, true))) + goto cleanup; + + ret = 0; + + cleanup: + virBufferFreeAndReset(&buf); + VIR_FREE(tmp); + return ret; +} diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h index 3708c5e..8b23f95 100644 --- a/src/util/virstoragefile.h +++ b/src/util/virstoragefile.h @@ -327,4 +327,8 @@ virStorageSourcePtr virStorageSourceNewFromBacking(virStorageSourcePtr parent); char *virStorageFileSimplifyPath(const char *path, bool allow_relative); +int virStorageFileGetRelativeBackingPath(virStorageSourcePtr from, + virStorageSourcePtr to, + char **relpath); + #endif /* __VIR_STORAGE_FILE_H__ */ diff --git a/tests/virstoragetest.c b/tests/virstoragetest.c index 57f16ca..80d73ca 100644 --- a/tests/virstoragetest.c +++ b/tests/virstoragetest.c @@ -560,6 +560,85 @@ testPathSimplify(const void *args) } +virStorageSource backingchain[9]; + +static void +testPathRelativePrepare(void) +{ + size_t i; + + for (i = 0; i < ARRAY_CARDINALITY(backingchain) - 1; i++) { + backingchain[i].backingStore = &backingchain[i+1]; + } + + backingchain[0].relPath = (char *) "/path/to/some/img"; + backingchain[0].backingRelative = false; + + backingchain[1].relPath = (char *) "asdf"; + backingchain[1].backingRelative = true; + + backingchain[2].relPath = (char *) "test"; + backingchain[2].backingRelative = true; + + backingchain[3].relPath = (char *) "blah"; + backingchain[3].backingRelative = true; + + backingchain[4].relPath = (char *) "/path/to/some/other/img"; + backingchain[4].backingRelative = false; + + backingchain[5].relPath = (char *) "../relative/in/other/path"; + backingchain[5].backingRelative = true; + + backingchain[6].relPath = (char *) "test"; + backingchain[6].backingRelative = true; + + backingchain[7].relPath = (char *) "../../../../../below"; + backingchain[7].backingRelative = true; + + backingchain[8].relPath = (char *) "a/little/more/upwards"; + backingchain[8].backingRelative = true; +} + + +struct testPathRelativeBacking +{ + virStorageSourcePtr from; + virStorageSourcePtr to; + + const char *expect; +}; + +static int +testPathRelative(const void *args) +{ + const struct testPathRelativeBacking *data = args; + char *actual = NULL; + int ret = -1; + + if (virStorageFileGetRelativeBackingPath(data->from, + data->to, + &actual) < 0) { + fprintf(stderr, "relative backing path resolution failed\n"); + goto cleanup; + } + + if (STRNEQ_NULLABLE(data->expect, actual)) { + fprintf(stderr, "relative path resolution from '%s' to '%s': " + "expected '%s', got '%s'\n", + data->from->relPath, data->to->relPath, + NULLSTR(data->expect), NULLSTR(actual)); + goto cleanup; + } + + ret = 0; + + cleanup: + VIR_FREE(actual); + + return ret; +} + + static int mymain(void) { @@ -567,6 +646,7 @@ mymain(void) virCommandPtr cmd = NULL; struct testChainData data; struct testPathSimplifyData data3; + struct testPathRelativeBacking data4; virStorageSourcePtr chain = NULL; /* Prep some files with qemu-img; if that is not found on PATH, or @@ -1099,6 +1179,27 @@ mymain(void) TEST_SIMPLIFY(21, "some/path/to/image.qcow/../image2.qcow/../image3.qcow/", "some/path/to/image3.qcow", "some/path/to/image3.qcow"); +#define TEST_RELATIVE_BACKING(id, FROM, TO, EXPECT) \ + do { \ + data4.from = &FROM; \ + data4.to = &TO; \ + data4.expect = EXPECT; \ + if (virtTestRun("Path relative resolve " #id, \ + testPathRelative, &data4) < 0) \ + ret = -1; \ + } while (0) + + testPathRelativePrepare(); + + TEST_RELATIVE_BACKING(1, backingchain[0], backingchain[1], NULL); + TEST_RELATIVE_BACKING(2, backingchain[1], backingchain[2], "test"); + TEST_RELATIVE_BACKING(3, backingchain[2], backingchain[3], "blah"); + TEST_RELATIVE_BACKING(4, backingchain[1], backingchain[3], "blah"); + TEST_RELATIVE_BACKING(5, backingchain[1], backingchain[4], NULL); + TEST_RELATIVE_BACKING(6, backingchain[5], backingchain[6], "../relative/in/other/test"); + TEST_RELATIVE_BACKING(7, backingchain[5], backingchain[7], "../../../below"); + TEST_RELATIVE_BACKING(8, backingchain[5], backingchain[8], "../../../a/little/more/upwards"); + cleanup: /* Final cleanup */ virStorageSourceFree(chain); -- 1.9.3

Use virStorageFileSimplifyPathInternal to canonicalize gluster paths via a callback and use it for the unique volume path retrieval API. --- src/storage/storage_backend_gluster.c | 81 +++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c index 1a844c9..25d2aed 100644 --- a/src/storage/storage_backend_gluster.c +++ b/src/storage/storage_backend_gluster.c @@ -533,6 +533,7 @@ typedef virStorageFileBackendGlusterPriv *virStorageFileBackendGlusterPrivPtr; struct _virStorageFileBackendGlusterPriv { glfs_t *vol; + char *uid; }; @@ -547,6 +548,7 @@ virStorageFileBackendGlusterDeinit(virStorageSourcePtr src) if (priv->vol) glfs_fini(priv->vol); + VIR_FREE(priv->uid); VIR_FREE(priv); src->drv->priv = NULL; @@ -712,6 +714,81 @@ virStorageFileBackendGlusterAccess(virStorageSourcePtr src, return glfs_access(priv->vol, src->path, mode); } +static int +virStorageFileBackendGlusterReadlinkCallback(const char *path, + char **link, + void *data) +{ + virStorageFileBackendGlusterPrivPtr priv = data; + char *buf = NULL; + size_t bufsiz = 0; + ssize_t ret; + struct stat st; + + *link = NULL; + + if (glfs_stat(priv->vol, path, &st) < 0) { + virReportSystemError(errno, + _("failed to stat gluster path '%s'"), + path); + return -1; + } + + if (!S_ISLNK(st.st_mode)) + return 1; + + realloc: + if (VIR_EXPAND_N(buf, bufsiz, 256) < 0) + goto error; + + if ((ret = glfs_readlink(priv->vol, path, buf, bufsiz)) < 0) { + virReportSystemError(errno, + _("failed to read link of gluster file '%s'"), + path); + goto error; + } + + if (ret == bufsiz) + goto realloc; + + buf[ret] = '\0'; + + *link = buf; + + return 0; + + error: + VIR_FREE(buf); + return -1; +} + + +static const char * +virStorageFileBackendGlusterGetUniqueIdentifier(virStorageSourcePtr src) +{ + virStorageFileBackendGlusterPrivPtr priv = src->drv->priv; + char *canonPath = NULL; + + if (priv->uid) + return priv->uid; + + if (!(canonPath = virStorageFileSimplifyPathInternal(src->path, + false, + virStorageFileBackendGlusterReadlinkCallback, + priv))) + return NULL; + + ignore_value(virAsprintf(&priv->uid, "gluster://%s:%s/%s/%s", + src->hosts->name, + src->hosts->port, + src->volume, + canonPath)); + + VIR_FREE(canonPath); + + return priv->uid; +} + virStorageFileBackend virStorageFileBackendGluster = { .type = VIR_STORAGE_TYPE_NETWORK, @@ -724,4 +801,8 @@ virStorageFileBackend virStorageFileBackendGluster = { .storageFileStat = virStorageFileBackendGlusterStat, .storageFileReadHeader = virStorageFileBackendGlusterReadHeader, .storageFileAccess = virStorageFileBackendGlusterAccess, + + .storageFileGetUniqueIdentifier = virStorageFileBackendGlusterGetUniqueIdentifier, + + }; -- 1.9.3

To allow changing the name that is recorded in the overlay of the TOP image used in a block commit operation, we need to specify the backing name to qemu. This is done via the "backing-file" attribute to the block-commit commad. --- src/qemu/qemu_driver.c | 1 + src/qemu/qemu_monitor.c | 9 ++++++--- src/qemu/qemu_monitor.h | 1 + src/qemu/qemu_monitor_json.c | 2 ++ src/qemu/qemu_monitor_json.h | 1 + tests/qemumonitorjsontest.c | 2 +- 6 files changed, 12 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 2b852eb..5a4d3b4 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -15509,6 +15509,7 @@ qemuDomainBlockCommit(virDomainPtr dom, ret = qemuMonitorBlockCommit(priv->mon, device, top && !topIndex ? top : topSource->path, base && !baseIndex ? base : baseSource->path, + NULL, bandwidth); qemuDomainObjExitMonitor(driver, vm); diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 912bea1..590081c 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -3234,13 +3234,15 @@ qemuMonitorTransaction(qemuMonitorPtr mon, virJSONValuePtr actions) int qemuMonitorBlockCommit(qemuMonitorPtr mon, const char *device, const char *top, const char *base, + const char *backingName, unsigned long bandwidth) { int ret = -1; unsigned long long speed; - VIR_DEBUG("mon=%p, device=%s, top=%s, base=%s, bandwidth=%ld", - mon, device, top, base, bandwidth); + VIR_DEBUG("mon=%p, device=%s, top=%s, base=%s, backingName=%s, " + "bandwidth=%ld", + mon, device, top, base, backingName, bandwidth); /* Convert bandwidth MiB to bytes - unfortunately the JSON QMP protocol is * limited to LLONG_MAX also for unsigned values */ @@ -3254,7 +3256,8 @@ qemuMonitorBlockCommit(qemuMonitorPtr mon, const char *device, speed <<= 20; if (mon->json) - ret = qemuMonitorJSONBlockCommit(mon, device, top, base, speed); + ret = qemuMonitorJSONBlockCommit(mon, device, top, base, + backingName, speed); else virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", _("block-commit requires JSON monitor")); diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index de724bf..2cac1b3 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -662,6 +662,7 @@ int qemuMonitorBlockCommit(qemuMonitorPtr mon, const char *device, const char *top, const char *base, + const char *backingName, unsigned long bandwidth) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4); diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 04249c5..5b0766a 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -3441,6 +3441,7 @@ qemuMonitorJSONTransaction(qemuMonitorPtr mon, virJSONValuePtr actions) int qemuMonitorJSONBlockCommit(qemuMonitorPtr mon, const char *device, const char *top, const char *base, + const char *backingName, unsigned long long speed) { int ret = -1; @@ -3452,6 +3453,7 @@ qemuMonitorJSONBlockCommit(qemuMonitorPtr mon, const char *device, "U:speed", speed, "s:top", top, "s:base", base, + "S:backing-file", backingName, NULL); if (!cmd) return -1; diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 5dda0ba..c30803f 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -261,6 +261,7 @@ int qemuMonitorJSONBlockCommit(qemuMonitorPtr mon, const char *device, const char *top, const char *base, + const char *backingName, unsigned long long bandwidth) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4); diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c index 47d7481..e618c67 100644 --- a/tests/qemumonitorjsontest.c +++ b/tests/qemumonitorjsontest.c @@ -1164,7 +1164,7 @@ GEN_TEST_FUNC(qemuMonitorJSONAddDevice, "some_dummy_devicestr") GEN_TEST_FUNC(qemuMonitorJSONSetDrivePassphrase, "vda", "secret_passhprase") GEN_TEST_FUNC(qemuMonitorJSONDriveMirror, "vdb", "/foo/bar", NULL, 1024, VIR_DOMAIN_BLOCK_REBASE_SHALLOW | VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT) -GEN_TEST_FUNC(qemuMonitorJSONBlockCommit, "vdb", "/foo/bar1", "/foo/bar2", 1024) +GEN_TEST_FUNC(qemuMonitorJSONBlockCommit, "vdb", "/foo/bar1", "/foo/bar2", NULL, 1024) GEN_TEST_FUNC(qemuMonitorJSONDrivePivot, "vdb", NULL, NULL) GEN_TEST_FUNC(qemuMonitorJSONScreendump, "/foo/bar") GEN_TEST_FUNC(qemuMonitorJSONOpenGraphics, "spice", "spicefd", false) -- 1.9.3

Introduce flag for the block commit API to allow the commit operation to leave the chain relatively addressed. Also adds a virsh switch to enable this behavior. --- include/libvirt/libvirt.h.in | 4 ++++ tools/virsh-domain.c | 7 +++++++ 2 files changed, 11 insertions(+) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 260c971..2df7fc8 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -2588,6 +2588,10 @@ typedef enum { VIR_DOMAIN_BLOCK_COMMIT_DELETE = 1 << 1, /* Delete any files that are now invalid after their contents have been committed */ + VIR_DOMAIN_BLOCK_COMMIT_RELATIVE = 1 << 2, /* try to keep the backing chain + relative if the components + removed by the commit are + already relative */ } virDomainBlockCommitFlags; int virDomainBlockCommit(virDomainPtr dom, const char *disk, const char *base, diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 84a6706..5c3a142 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -1492,6 +1492,8 @@ blockJobImpl(vshControl *ctl, const vshCmd *cmd, flags |= VIR_DOMAIN_BLOCK_COMMIT_SHALLOW; if (vshCommandOptBool(cmd, "delete")) flags |= VIR_DOMAIN_BLOCK_COMMIT_DELETE; + if (vshCommandOptBool(cmd, "keep-relative")) + flags |= VIR_DOMAIN_BLOCK_COMMIT_RELATIVE; ret = virDomainBlockCommit(dom, path, base, top, bandwidth, flags); break; case VSH_CMD_BLOCK_JOB_COPY: @@ -1612,6 +1614,11 @@ static const vshCmdOptDef opts_block_commit[] = { .type = VSH_OT_BOOL, .help = N_("with --wait, don't wait for cancel to finish") }, + {.name = "keep-relative", + .type = VSH_OT_BOOL, + .help = N_("keep the backing chain relative if it was relatively " + "referenced if it was before") + }, {.name = NULL} }; -- 1.9.3

Now that we are able to select images from the backing chain via indexed access we should also convert possible network sources to qemu-compatible strings before passing them to qemu. --- src/qemu/qemu_capabilities.c | 5 +++++ src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_driver.c | 33 +++++++++++++++++++++++++++++---- 3 files changed, 35 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 03d8842..ccd9a93 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -256,6 +256,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, "usb-kbd", /* 165 */ "host-pci-multidomain", "msg-timestamp", + "block-commit-backing-name", ); @@ -3100,6 +3101,10 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps, if (virQEMUCapsProbeQMPCommandLine(qemuCaps, mon) < 0) goto cleanup; + /* TODO, WIP: We shall test this */ + if (qemuCaps->version >= 2000000) + virQEMUCapsSet(qemuCaps, QEMU_CAPS_BLOCKPULL_BACKING_NAME); + ret = 0; cleanup: VIR_FREE(package); diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index d755caa..773298d 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -206,6 +206,7 @@ enum virQEMUCapsFlags { QEMU_CAPS_DEVICE_USB_KBD = 165, /* -device usb-kbd */ QEMU_CAPS_HOST_PCI_MULTIDOMAIN = 166, /* support domain > 0 in host pci address */ QEMU_CAPS_MSG_TIMESTAMP = 167, /* -msg timestamp */ + QEMU_CAPS_BLOCKPULL_BACKING_NAME = 168, /* support for backing name tweaking */ QEMU_CAPS_LAST, /* this must always be the last item */ }; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index e2eccee..1e7ad1a 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -15414,8 +15414,12 @@ qemuDomainBlockCommit(virDomainPtr dom, unsigned int baseIndex = 0; const char *top_parent = NULL; bool clean_access = false; + char *topPath = NULL; + char *basePath = NULL; + char *backingPath = NULL; - virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW, -1); + virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW | + VIR_DOMAIN_BLOCK_COMMIT_RELATIVE, -1); if (!(vm = qemuDomObjFromDomain(dom))) goto cleanup; @@ -15500,6 +15504,26 @@ qemuDomainBlockCommit(virDomainPtr dom, VIR_DISK_CHAIN_READ_WRITE) < 0)) goto endjob; + if (qemuGetDriveSourceString(topSource, NULL, &topPath) < 0) + goto endjob; + + if (qemuGetDriveSourceString(baseSource, NULL, &basePath) < 0) + goto endjob; + + if (flags & VIR_DOMAIN_BLOCK_COMMIT_RELATIVE) { + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKPULL_BACKING_NAME)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("this qemu doesn't support relative blockpull")); + goto endjob; + } + + if (virStorageFileGetRelativeBackingPath(topSource, baseSource, + &backingPath) < 0) + goto endjob; + + /* XXX should we error out? */ + } + /* Start the commit operation. Pass the user's original spelling, * if any, through to qemu, since qemu may behave differently * depending on whether the input was specified as relative or @@ -15507,9 +15531,7 @@ qemuDomainBlockCommit(virDomainPtr dom, * thing if the user specified a relative name). */ qemuDomainObjEnterMonitor(driver, vm); ret = qemuMonitorBlockCommit(priv->mon, device, - top && !topIndex ? top : topSource->path, - base && !baseIndex ? base : baseSource->path, - NULL, + topPath, basePath, backingPath, bandwidth); qemuDomainObjExitMonitor(driver, vm); @@ -15527,6 +15549,9 @@ qemuDomainBlockCommit(virDomainPtr dom, vm = NULL; cleanup: + VIR_FREE(topPath); + VIR_FREE(basePath); + VIR_FREE(backingPath); VIR_FREE(device); if (vm) virObjectUnlock(vm); -- 1.9.3