[libvirt] [PATCH 8/8] save: support O_DIRECT during qemu saves
Eric Blake
eblake at redhat.com
Thu Jul 14 14:24:35 UTC 2011
Wire together the previous patches to support O_DIRECT via API
request in qemu.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal, doCoreDump):
Add parameter.
(qemuDomainSaveFlags, qemuDomainManagedSave, qemudDomainCoreDump)
(processWatchdogEvent): Update callers.
---
src/qemu/qemu_driver.c | 53 ++++++++++++++++++++++++++++++++---------------
1 files changed, 36 insertions(+), 17 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ceeef1c..7687e18 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -87,6 +87,7 @@
#include "configmake.h"
#include "threadpool.h"
#include "locking/lock_manager.h"
+#include "virdirect.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -2110,7 +2111,7 @@ qemuCompressProgramName(int compress)
static int
qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
virDomainObjPtr vm, const char *path,
- int compressed)
+ int compressed, bool direct)
{
char *xml = NULL;
struct qemud_save_header header;
@@ -2125,6 +2126,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
int fd = -1;
uid_t uid = getuid();
gid_t gid = getgid();
+ virDirectFdPtr directFd = NULL;
memset(&header, 0, sizeof(header));
memcpy(header.magic, QEMUD_SAVE_MAGIC, sizeof(header.magic));
@@ -2208,14 +2210,14 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
/* First try creating the file as root */
if (!is_reg) {
- fd = open(path, O_WRONLY | O_TRUNC);
+ fd = open(path, O_WRONLY | O_TRUNC | (direct ? O_DIRECT : 0));
if (fd < 0) {
virReportSystemError(errno, _("unable to open %s"), path);
goto endjob;
}
} else {
- if ((fd = virFileOpenAs(path, O_CREAT|O_TRUNC|O_WRONLY,
- S_IRUSR|S_IWUSR,
+ int oflags = O_CREAT | O_TRUNC | O_WRONLY | (direct ? O_DIRECT : 0);
+ if ((fd = virFileOpenAs(path, oflags, S_IRUSR | S_IWUSR,
uid, gid, 0)) < 0) {
/* If we failed as root, and the error was permission-denied
(EACCES or EPERM), assume it's on a network-connected share
@@ -2261,7 +2263,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
/* Retry creating the file as driver->user */
- if ((fd = virFileOpenAs(path, O_CREAT|O_TRUNC|O_WRONLY,
+ if ((fd = virFileOpenAs(path, oflags,
S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP,
driver->user, driver->group,
VIR_FILE_OPEN_AS_UID)) < 0) {
@@ -2279,6 +2281,9 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
}
}
+ if (direct && (directFd = virDirectFdNew(&fd, path)) == NULL)
+ goto endjob;
+
/* Write header to file, followed by XML */
if (qemuDomainSaveHeader(fd, path, xml, &header) < 0) {
VIR_FORCE_CLOSE(fd);
@@ -2294,6 +2299,8 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
virReportSystemError(errno, _("unable to close %s"), path);
goto endjob;
}
+ if (virDirectFdClose(directFd) < 0)
+ goto endjob;
ret = 0;
@@ -2326,6 +2333,7 @@ endjob:
cleanup:
VIR_FORCE_CLOSE(fd);
+ virDirectFdFree(directFd);
VIR_FREE(xml);
if (ret != 0 && is_reg)
unlink(path);
@@ -2361,7 +2369,7 @@ qemuDomainSaveFlags(virDomainPtr dom, const char *path, const char *dxml,
int ret = -1;
virDomainObjPtr vm = NULL;
- virCheckFlags(0, -1);
+ virCheckFlags(VIR_DOMAIN_SAVE_DIRECT, -1);
if (dxml) {
qemuReportError(VIR_ERR_INVALID_ARG, "%s",
_("xml modification unsupported"));
@@ -2403,7 +2411,8 @@ qemuDomainSaveFlags(virDomainPtr dom, const char *path, const char *dxml,
goto cleanup;
}
- ret = qemuDomainSaveInternal(driver, dom, vm, path, compressed);
+ ret = qemuDomainSaveInternal(driver, dom, vm, path, compressed,
+ (flags & VIR_DOMAIN_SAVE_DIRECT) != 0);
vm = NULL;
cleanup:
@@ -2441,7 +2450,7 @@ qemuDomainManagedSave(virDomainPtr dom, unsigned int flags)
int ret = -1;
int compressed;
- virCheckFlags(0, -1);
+ virCheckFlags(VIR_DOMAIN_SAVE_DIRECT, -1);
qemuDriverLock(driver);
vm = virDomainFindByUUID(&driver->domains, dom->uuid);
@@ -2466,7 +2475,8 @@ qemuDomainManagedSave(virDomainPtr dom, unsigned int flags)
VIR_INFO("Saving state to %s", name);
compressed = QEMUD_SAVE_FORMAT_RAW;
- ret = qemuDomainSaveInternal(driver, dom, vm, name, compressed);
+ ret = qemuDomainSaveInternal(driver, dom, vm, name, compressed,
+ (flags & VIR_DOMAIN_SAVE_DIRECT) != 0);
vm = NULL;
cleanup:
@@ -2550,18 +2560,24 @@ static int
doCoreDump(struct qemud_driver *driver,
virDomainObjPtr vm,
const char *path,
- enum qemud_save_formats compress)
+ enum qemud_save_formats compress,
+ bool direct)
{
int fd = -1;
int ret = -1;
+ virDirectFdPtr directFd = NULL;
/* Create an empty file with appropriate ownership. */
- if ((fd = open(path, O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR)) < 0) {
+ if ((fd = open(path, O_CREAT|O_TRUNC|O_WRONLY | (direct ? O_DIRECT : 0),
+ S_IRUSR|S_IWUSR)) < 0) {
qemuReportError(VIR_ERR_OPERATION_FAILED,
_("failed to create '%s'"), path);
goto cleanup;
}
+ if (direct && (directFd = virDirectFdNew(&fd, path)) == NULL)
+ goto cleanup;
+
if (qemuMigrationToFile(driver, vm, fd, 0, path,
qemuCompressProgramName(compress), true, false) < 0)
goto cleanup;
@@ -2572,11 +2588,14 @@ doCoreDump(struct qemud_driver *driver,
path);
goto cleanup;
}
+ if (virDirectFdClose(directFd) < 0)
+ goto cleanup;
ret = 0;
cleanup:
VIR_FORCE_CLOSE(fd);
+ virDirectFdClose(directFd);
if (ret != 0)
unlink(path);
return ret;
@@ -2620,7 +2639,7 @@ static int qemudDomainCoreDump(virDomainPtr dom,
int ret = -1;
virDomainEventPtr event = NULL;
- virCheckFlags(VIR_DUMP_LIVE | VIR_DUMP_CRASH, -1);
+ virCheckFlags(VIR_DUMP_LIVE | VIR_DUMP_CRASH | VIR_DUMP_DIRECT, -1);
qemuDriverLock(driver);
vm = virDomainFindByUUID(&driver->domains, dom->uuid);
@@ -2661,7 +2680,8 @@ static int qemudDomainCoreDump(virDomainPtr dom,
}
}
- ret = doCoreDump(driver, vm, path, getCompressionType(driver));
+ ret = doCoreDump(driver, vm, path, getCompressionType(driver),
+ (flags & VIR_DUMP_DIRECT) != 0);
if (ret < 0)
goto endjob;
@@ -2832,10 +2852,9 @@ static void processWatchdogEvent(void *data, void *opaque)
goto endjob;
}
- ret = doCoreDump(driver,
- wdEvent->vm,
- dumpfile,
- getCompressionType(driver));
+ /* XXX wire up qemu.conf to support whether to do direct dumps */
+ ret = doCoreDump(driver, wdEvent->vm, dumpfile,
+ getCompressionType(driver), false);
if (ret < 0)
qemuReportError(VIR_ERR_OPERATION_FAILED,
"%s", _("Dump failed"));
--
1.7.4.4
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