From ac5067f1e2e98181ee0e9230f756697f50d853eb Mon Sep 17 00:00:00 2001

From: Daniel P. Berrange <berrange@redhat.com>

Date: Mon, 14 Jun 2010 18:09:15 +0100

Subject: [PATCH 05/11] Add an API for iterating over disk paths

There is duplicated code which iterates over disk backing stores

performing some action. Provide a convenient helper for doing

this to eliminate duplication & risk of mistakes with disk format

probing

* src/conf/domain_conf.c, src/conf/domain_conf.h,

  src/libvirt_private.syms: Add virDomainDiskDefForeachPath()

---

 src/conf/domain_conf.c   |   99 ++++++++++++++++++++++++++++++++++++++++++++++

 src/conf/domain_conf.h   |   11 +++++

 src/libvirt_private.syms |    1 +

 3 files changed, 111 insertions(+), 0 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c

index 378c06e..b20ca97 100644

--- a/src/conf/domain_conf.c

+++ b/src/conf/domain_conf.c

@@ -45,6 +45,7 @@

 #include "macvtap.h"

 #include "nwfilter_conf.h"

 #include "ignore-value.h"

+#include "storage_file.h"

 #define VIR_FROM_THIS VIR_FROM_DOMAIN

@@ -7273,4 +7274,102 @@ done:

 }

+int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk,

+                                bool allowProbing,

+                                bool ignoreOpenFailure,

+                                virDomainDiskDefPathIterator iter,

+                                void *opaque)

+{

+    virHashTablePtr paths;

+    int format;

+    int ret = -1;

+    size_t depth = 0;

+    char *nextpath = NULL;

+

+    if (!disk->src)

+        return 0;

+

+    if (disk->driverType) {

+        const char *formatStr = disk->driverType;

+        if (STREQ(formatStr, "aio"))

+            formatStr = "raw"; /* Xen compat */

+

+        if ((format = virStorageFileFormatTypeFromString(formatStr)) < 0) {

+            virDomainReportError(VIR_ERR_INTERNAL_ERROR,

+                                 _("unknown disk format '%s' for %s"),

+                                 disk->driverType, disk->src);

+            return -1;

+        }

+    } else {

+        if (allowProbing) {

+            format = VIR_STORAGE_FILE_AUTO;

+        } else {

+            virDomainReportError(VIR_ERR_INTERNAL_ERROR,

+                                 _("no disk format for %s and probing is disabled"),

+                                 disk->src);

+            return -1;

+        }

+    }

+

+    paths = virHashCreate(5);

+

+    do {

+        virStorageFileMetadata meta;

+        const char *path = nextpath ? nextpath : disk->src;

+        int fd;

+

+        if (iter(disk, path, depth, opaque) < 0)

+            goto cleanup;

+

+        if (virHashLookup(paths, path)) {

+            virDomainReportError(VIR_ERR_INTERNAL_ERROR,

+                                 _("backing store for %s is self-referential"),

+                                 disk->src);

+            goto cleanup;

+        }

+

+        if ((fd = open(path, O_RDONLY)) < 0) {

+            if (ignoreOpenFailure) {

+                char ebuf[1024];

+                VIR_WARN("Ignoring open failure on %s: %s", path,

+                         virStrerror(errno, ebuf, sizeof(ebuf)));

+                break;

+            } else {

+                virReportSystemError(errno,

+                                     _("unable to open disk path %s"),

+                                     path);

+                goto cleanup;

+            }

+        }

+

+        if (virStorageFileGetMetadataFromFD(path, fd, format, &meta) < 0) {

+            close(fd);

+            goto cleanup;

+        }

+        close(fd);

+

+        if (virHashAddEntry(paths, path, (void*)0x1) < 0) {

+            virReportOOMError();

+            goto cleanup;

+        }

+

+        depth++;

+        nextpath = meta.backingStore;

+

+        format = meta.backingStoreFormat;

+

+        if (format == VIR_STORAGE_FILE_AUTO &&

+            !allowProbing)

+            format = VIR_STORAGE_FILE_RAW; /* Stops further recursion */

+    } while (nextpath);

+

+    ret = 0;

+

+cleanup:

+    virHashFree(paths, NULL);

+    VIR_FREE(nextpath);

+

+    return ret;

+}

+

 #endif /* ! PROXY */

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h

index 01da17e..d46869e 100644

--- a/src/conf/domain_conf.h

+++ b/src/conf/domain_conf.h

@@ -1079,6 +1079,17 @@ int virDomainChrDefForeach(virDomainDefPtr def,

                            void *opaque);

+typedef int (*virDomainDiskDefPathIterator)(virDomainDiskDefPtr disk,

+                                            const char *path,

+                                            size_t depth,

+                                            void *opaque);

+

+int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk,

+                                bool allowProbing,

+                                bool ignoreOpenFailure,

+                                virDomainDiskDefPathIterator iter,

+                                void *opaque);

+

 VIR_ENUM_DECL(virDomainVirt)

 VIR_ENUM_DECL(virDomainBoot)

 VIR_ENUM_DECL(virDomainFeature)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms

index 4607f49..b5f3695 100644

--- a/src/libvirt_private.syms

+++ b/src/libvirt_private.syms

@@ -225,6 +225,7 @@ virDomainSnapshotDefFormat;

 virDomainSnapshotAssignDef;

 virDomainObjAssignDef;

 virDomainChrDefForeach;

+virDomainDiskDefForeachPath;

 # domain_event.h

-- 

1.7.1.1