[PATCH v2 13/17] qemu: Prepare storage backing chain traversal code for FD passed images
We assume that FD passed images already exist so all existance checks
are skipped.
For the case that a FD-passed image is passed without a terminated
backing chain (thus forcing us to detect) we attempt to read the header
from the FD.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_domain.c | 23 ++++++++++++++---------
src/storage_file/storage_source.c | 15 +++++++++++++++
2 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 7dc4ef4ddb..38883a57d8 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7679,16 +7679,20 @@ qemuDomainDetermineDiskChain(virQEMUDriver *driver,
disksrc->format > VIR_STORAGE_FILE_NONE &&
disksrc->format < VIR_STORAGE_FILE_BACKING) {
+ /* terminate the chain for such images as the code below would do */
+ if (!disksrc->backingStore)
+ disksrc->backingStore = virStorageSourceNew();
+
+ /* we assume that FD-passed disks always exist */
+ if (virStorageSourceIsFD(disksrc))
+ return 0;
+
if (!virFileExists(disksrc->path)) {
virStorageSourceReportBrokenChain(errno, disksrc, disksrc);
return -1;
}
- /* terminate the chain for such images as the code below would do */
- if (!disksrc->backingStore)
- disksrc->backingStore = virStorageSourceNew();
-
/* host cdrom requires special treatment in qemu, so we need to check
* whether a block device is a cdrom */
if (disk->device == VIR_DOMAIN_DISK_DEVICE_CDROM &&
@@ -7700,12 +7704,14 @@ qemuDomainDetermineDiskChain(virQEMUDriver *driver,
return 0;
}
- src = disksrc;
/* skip to the end of the chain if there is any */
- while (virStorageSourceHasBacking(src)) {
- int rv = virStorageSourceSupportsAccess(src);
+ for (src = disksrc; virStorageSourceHasBacking(src); src = src->backingStore) {
+ int rv;
+
+ if (virStorageSourceIsFD(src))
+ continue;
- if (rv < 0)
+ if ((rv = virStorageSourceSupportsAccess(src)) < 0)
return -1;
if (rv > 0) {
@@ -7720,7 +7726,6 @@ qemuDomainDetermineDiskChain(virQEMUDriver *driver,
virStorageSourceDeinit(src);
}
- src = src->backingStore;
}
/* We skipped to the end of the chain. Skip detection if there's the
diff --git a/src/storage_file/storage_source.c b/src/storage_file/storage_source.c
index ab0cdf2b12..7954b255a6 100644
--- a/src/storage_file/storage_source.c
+++ b/src/storage_file/storage_source.c
@@ -1264,6 +1264,21 @@ virStorageSourceGetMetadataRecurseReadHeader(virStorageSource
*src,
int ret = -1;
ssize_t len;
+ if (virStorageSourceIsFD(src)) {
+ if (!src->fdtuple) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("fd passed image source not initialized"));
+ return -1;
+ }
+
+ if ((len = virFileReadHeaderFD(src->fdtuple->fds[0],
+ VIR_STORAGE_MAX_HEADER, buf)) < 0)
+ return -1;
+
+ *headerLen = len;
+ return 0;
+ }
+
if (virStorageSourceInitAs(src, uid, gid) < 0)
return -1;
--
2.38.1