[libvirt] [PATCH 3/2] qemu: Always use iohelper for domain save
This is probably not strictly needed as save operation is not live but
we may have other reasons to avoid blocking qemu's main loop.
---
src/qemu/qemu_driver.c | 44 +++++++++++++++++++-------------------------
1 files changed, 19 insertions(+), 25 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 52350f2..0cac6a5 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2522,7 +2522,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
int fd = -1;
int directFlag = 0;
virFileWrapperFdPtr wrapperFd = NULL;
- bool bypass_cache = flags & VIR_DOMAIN_SAVE_BYPASS_CACHE;
+ unsigned int wrapperFlags = VIR_FILE_WRAPPER_NON_BLOCKING;
if (qemuProcessAutoDestroyActive(driver, vm)) {
qemuReportError(VIR_ERR_OPERATION_INVALID,
@@ -2613,7 +2613,8 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
header.xml_len = len;
/* Obtain the file handle. */
- if (bypass_cache) {
+ if ((flags & VIR_DOMAIN_SAVE_BYPASS_CACHE)) {
+ wrapperFlags |= VIR_FILE_WRAPPER_BYPASS_CACHE;
directFlag = virFileDirectFdFlag();
if (directFlag < 0) {
qemuReportError(VIR_ERR_OPERATION_FAILED, "%s",
@@ -2625,9 +2626,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
&needUnlink, &bypassSecurityDriver);
if (fd < 0)
goto endjob;
- if (bypass_cache &&
- !(wrapperFd = virFileWrapperFdNew(&fd, path,
- VIR_FILE_WRAPPER_BYPASS_CACHE)))
+ if (!(wrapperFd = virFileWrapperFdNew(&fd, path, wrapperFlags)))
goto endjob;
/* Write header to file, followed by XML */
@@ -2643,27 +2642,22 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
QEMU_ASYNC_JOB_SAVE) < 0)
goto endjob;
- /* Touch up file header to mark image complete. */
- if (bypass_cache) {
- /* Reopen the file to touch up the header, since we aren't set
- * up to seek backwards on wrapperFd. The reopened fd will
- * trigger a single page of file system cache pollution, but
- * that's acceptable. */
- if (VIR_CLOSE(fd) < 0) {
- virReportSystemError(errno, _("unable to close %s"), path);
- goto endjob;
- }
- if (virFileWrapperFdClose(wrapperFd) < 0)
- goto endjob;
- fd = qemuOpenFile(driver, path, O_WRONLY, NULL, NULL);
- if (fd < 0)
- goto endjob;
- } else {
- if (lseek(fd, 0, SEEK_SET) != 0) {
- virReportSystemError(errno, _("unable to seek %s"), path);
- goto endjob;
- }
+ /* Touch up file header to mark image complete. */
+
+ /* Reopen the file to touch up the header, since we aren't set
+ * up to seek backwards on wrapperFd. The reopened fd will
+ * trigger a single page of file system cache pollution, but
+ * that's acceptable. */
+ if (VIR_CLOSE(fd) < 0) {
+ virReportSystemError(errno, _("unable to close %s"), path);
+ goto endjob;
}
+ if (virFileWrapperFdClose(wrapperFd) < 0)
+ goto endjob;
+ fd = qemuOpenFile(driver, path, O_WRONLY, NULL, NULL);
+ if (fd < 0)
+ goto endjob;
+
memcpy(header.magic, QEMUD_SAVE_MAGIC, sizeof(header.magic));
if (safewrite(fd, &header, sizeof(header)) != sizeof(header)) {
virReportSystemError(errno, _("unable to write %s"), path);
--
1.7.8.4