From: Stefan Hajnoczi Date: Fri, 27 Jul 2012 08:05:20 +0000 (+0100) Subject: docs: add lazy refcounts bit to qcow2 specification X-Git-Tag: v1.2.0-rc0~77^2~6 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=dae8796d009ffc4d980db1f87f26eed0074be4ef;p=users%2Fdwmw2%2Fqemu.git docs: add lazy refcounts bit to qcow2 specification The lazy refcounts bit indicates that this image can take advantage of the dirty bit and that refcount updates can be postponed. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt index 339cdc1b58..36a559d886 100644 --- a/docs/specs/qcow2.txt +++ b/docs/specs/qcow2.txt @@ -86,7 +86,12 @@ in the description of a field. Bitmask of compatible features. An implementation can safely ignore any unknown bits that are set. - Bits 0-63: Reserved (set to 0) + Bit 0: Lazy refcounts bit. If this bit is set then + lazy refcount updates can be used. This means + marking the image file dirty and postponing + refcount metadata updates. + + Bits 1-63: Reserved (set to 0) 88 - 95: autoclear_features Bitmask of auto-clear features. An implementation may only