| Message ID | 1464943756-14143-2-git-send-email-famz@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 03.06.2016 um 10:48 hat Fam Zheng geschrieben: > Later the block layer will automatically lock the images to avoid unexpected > concurrent accesses to the same image, which will easily corrupt the metadata > or user data, unless in some very special cases, like migration. > > The exceptional cases like shared storage migration and testing should > set BDRV_O_SHARED_LOCK or BDRV_O_NO_LOCK to advise an appropriate > locking mode. > > Signed-off-by: Fam Zheng <famz@redhat.com> > Reviewed-by: Max Reitz <mreitz@redhat.com> Worth asserting in bdrv_open_common() that BDRV_O_NO_LOCK and BDRV_O_SHARED_LOCK aren't passed at the same time? Kevin > include/block/block.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/block/block.h b/include/block/block.h > index 70ea299..02b598b 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -94,6 +94,8 @@ typedef struct HDGeometry { > select an appropriate protocol driver, > ignoring the format layer */ > #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */ > +#define BDRV_O_NO_LOCK 0x20000 /* don't lock image file */ > +#define BDRV_O_SHARED_LOCK 0x40000 /* lock the image file in shared mode */ > > #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH) > > -- > 2.8.2 >
diff --git a/include/block/block.h b/include/block/block.h index 70ea299..02b598b 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -94,6 +94,8 @@ typedef struct HDGeometry { select an appropriate protocol driver, ignoring the format layer */ #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */ +#define BDRV_O_NO_LOCK 0x20000 /* don't lock image file */ +#define BDRV_O_SHARED_LOCK 0x40000 /* lock the image file in shared mode */ #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)