[libvirt] [PATCH 2/4] Avoid create/unlink with block devs used for QEMU save
It is possible to use block devices with domain save/restore. Upon
failure QEMU unlinks the path being saved to. This isn't good when
it is a block device !
* src/qemu/qemu_driver.c: Don't unlink block devices if save fails
---
src/qemu/qemu_driver.c | 22 ++++++++++++++++++++--
1 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 91fe963..41a516c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4787,6 +4787,8 @@ static int qemudDomainSaveFlag(virDomainPtr dom, const char *path,
int rc;
virDomainEventPtr event = NULL;
qemuDomainObjPrivatePtr priv;
+ struct stat sb;
+ int is_reg = 0;
memset(&header, 0, sizeof(header));
memcpy(header.magic, QEMUD_SAVE_MAGIC, sizeof(header.magic));
@@ -4840,6 +4842,21 @@ static int qemudDomainSaveFlag(virDomainPtr dom, const char *path,
}
header.xml_len = strlen(xml) + 1;
+ /* path might be a pre-existing block dev, in which case
+ * we need to skip the create step, and also avoid unlink
+ * in the failure case */
+ if (stat(path, &sb) < 0) {
+ if (errno != ENOENT) {
+ virReportSystemError(errno, _("unable to access %s"), path);
+ goto endjob;
+ } else {
+ is_reg = 1;
+ }
+ } else {
+ is_reg = S_ISREG(sb.st_mode);
+ }
+
+
/* Setup hook data needed by virFileOperation hook function */
hdata.dom = dom;
hdata.path = path;
@@ -4849,7 +4866,8 @@ static int qemudDomainSaveFlag(virDomainPtr dom, const char *path,
/* Write header to file, followed by XML */
/* First try creating the file as root */
- if ((rc = virFileOperation(path, O_CREAT|O_TRUNC|O_WRONLY,
+ if (is_reg &&
+ (rc = virFileOperation(path, O_CREAT|O_TRUNC|O_WRONLY,
S_IRUSR|S_IWUSR,
getuid(), getgid(),
qemudDomainSaveFileOpHook, &hdata,
@@ -5014,7 +5032,7 @@ endjob:
cleanup:
VIR_FREE(xml);
- if (ret != 0)
+ if (ret != 0 && is_reg)
unlink(path);
if (vm)
virDomainObjUnlock(vm);
--
1.6.5.2