On 07/19/2011 10:10 AM, Daniel P. Berrange wrote:
On Thu, Jul 14, 2011 at 08:24:28AM -0600, Eric Blake wrote:
In order to choose whether to use O_DIRECT when saving a domain image to a file, we need a new flag. But virDomainSave was implemented before our policy of all new APIs having a flag argument.
* include/libvirt/libvirt.h.in (virDomainSaveFlags): New prototype. * src/libvirt.c (virDomainSaveFlags): New API. * src/libvirt_public.syms: Export it. * src/driver.h (virDrvDomainSaveFlags): New driver callback. --- include/libvirt/libvirt.h.in | 14 ++++++ src/driver.h | 6 +++ src/libvirt.c | 94 +++++++++++++++++++++++++++++++++++++++++- src/libvirt_public.syms | 5 ++ 4 files changed, 118 insertions(+), 1 deletions(-)
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index d5a7105..d9a8694 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -659,6 +659,7 @@ typedef virDomainMemoryStatStruct *virDomainMemoryStatPtr; typedef enum { VIR_DUMP_CRASH = (1<< 0), /* crash after dump */ VIR_DUMP_LIVE = (1<< 1), /* live dump */ + VIR_DUMP_DIRECT = (1<< 2), /* Use O_DIRECT while saving */
I wonder if we're better off calling this 'BYPASS_CACHE' or something like since, since O_DIRECT is just an impl detail.
Absolutely a good idea! I'll fold that rename into v2, particularly since, if posix_fadvise ever gets smarter on Linux, then we can bypass the cache without using O_DIRECT. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org