9:13 p.m.
On 2012年12月13日 01:09, Daniel P. Berrange wrote:
On Tue, Dec 11, 2012 at 09:37:18PM +0800, Osier Yang wrote:
> This introduces a hash table for qemu driver, to store the shared
> disk's info as (@disk_path, {@ref_count, @orig_cdbfilter}). @ref_count
> is the number of domains which shares the disk. @orig_cdbfilter is
> the original cdbfilter setting of the shared disk, it will be used
> to restore the the disk's cdbfilter setting to original value by
> later patches.
>
> * src/qemu/qemu_conf.h: (Add member 'sharedDisks' of type
> virHashTablePtr; New struct qemuSharedDiskEntry;
> Declare helpers qemuAddSharedDisk,
> qemuRemoveSharedDisk)
> * src/qemu/qemu_conf.c (Implement the two helpers)
> * src/qemu/qemu_process.c (Update 'sharedDisks' when domain
> starting and shutdown)
> * src/qemu/qemu_driver.c (Update 'sharedDisks' when attaching
> or detaching disk).
>
> 0 is passed for orig_cdbfilter temporarily, later patches will update
> it.
> ---
> src/qemu/qemu_conf.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
> src/qemu/qemu_conf.h | 18 +++++++++++++++++
> src/qemu/qemu_driver.c | 17 ++++++++++++++++
> src/qemu/qemu_process.c | 17 +++++++++++++++-
> 4 files changed, 99 insertions(+), 1 deletions(-)
>
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index 8d380a1..2b21186 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
> @@ -556,3 +556,51 @@ qemuDriverCloseCallbackRunAll(virQEMUDriverPtr driver,
>
> virHashForEach(driver->closeCallbacks,
qemuDriverCloseCallbackRun,&data);
> }
> +
> +/* Increase ref count if the entry already exists, otherwise
> + * add a new entry.
> + */
> +int
> +qemuAddSharedDisk(virHashTablePtr sharedDisks,
> + const char *disk_path,
> + int orig_cdbfilter)
> +{
> + qemuSharedDiskEntryPtr entry = NULL;
> +
> + if ((entry = virHashLookup(sharedDisks, disk_path))) {
> + entry->ref++;
> + } else {
> + if (VIR_ALLOC(entry)< 0)
> + return -1;
> +
> + entry->ref = 1;
> + entry->orig_cdbfilter = orig_cdbfilter;
> +
> + if (virHashAddEntry(sharedDisks, disk_path, entry))
> + return -1;
Leaking 'entry' in failure path.
Okay, it's missed when changing the hash value from
only 'ref' count to a struct containing the original
cdbfilter value.
> @@ -6035,6 +6039,12 @@ qemuDomainAttachDeviceDiskLive(virConnectPtr conn,
> VIR_WARN("Failed to teardown cgroup for disk path %s",
> NULLSTR(disk->src));
> }
> +
> + if (ret == 0&& disk->shared) {
> + if (qemuAddSharedDisk(driver->sharedDisks, disk->src, 0)< 0)
> + VIR_WARN("Failed to add disk '%s' to shared disk
table",
> + disk->src);
> + }
You are not allowed to reference 'disk->src' unless you've validate
disk->type is FILE or BLOCK.
We only need to track this for TYPE_BLOCK in any case
Oh, right, okay.
> end:
> if (cgroup)
> virCgroupFree(&cgroup);
> @@ -6149,6 +6159,13 @@ qemuDomainDetachDeviceDiskLive(virQEMUDriverPtr driver,
> virDomainDiskDeviceTypeToString(disk->type));
> break;
> }
> +
> + if (ret == 0&& disk->shared) {
> + if (qemuRemoveSharedDisk(driver->sharedDisks, disk->src)< 0)
> + VIR_WARN("Failed to remove disk '%s' from shared disk
table",
> + disk->src);
> + }
Same crash problem here
> +
> return ret;
> }
>
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index ab04599..89152b8 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -3706,8 +3706,15 @@ int qemuProcessStart(virConnectPtr conn,
>
> /* in case a certain disk is desirous of CAP_SYS_RAWIO, add this */
> for (i = 0; i< vm->def->ndisks; i++) {
> - if (vm->def->disks[i]->rawio == 1)
> + virDomainDiskDefPtr disk = vm->def->disks[i];
> +
> + if (disk->rawio == 1)
> virCommandAllowCap(cmd, CAP_SYS_RAWIO);
> +
> + if (disk->shared) {
> + if (qemuAddSharedDisk(driver->sharedDisks, disk->src, 0)< 0)
> + goto cleanup;
> + }
And here
> }
>
> virCommandSetPreExecHook(cmd, qemuProcessHook,&hookData);
> @@ -4104,6 +4111,14 @@ void qemuProcessStop(virQEMUDriverPtr driver,
> flags&
VIR_QEMU_PROCESS_STOP_MIGRATED);
> virSecurityManagerReleaseLabel(driver->securityManager, vm->def);
>
> + for (i = 0; i< vm->def->ndisks; i++) {
> + virDomainDiskDefPtr disk = vm->def->disks[i];
> +
> + if (disk->shared) {
> + ignore_value(qemuRemoveSharedDisk(driver->sharedDisks,
disk->src));
> + }
> + }
And here
Daniel