Message ID | 20200422152129.167074-7-kwolf@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | block: Fix resize (extending) of short overlays | expand |
On 22.04.20 17:21, Kevin Wolf wrote: > For regular files, we always get BDRV_REQ_ZERO_WRITE behaviour from the > OS, so we can advertise the flag and just ignore it. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > Reviewed-by: Alberto Garcia <berto@igalia.com> > --- > block/file-posix.c | 4 ++++ > 1 file changed, 4 insertions(+) Reviewed-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/file-posix.c b/block/file-posix.c index 53f475ed61..1dca220a81 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -702,6 +702,10 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, #endif bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK; + if (S_ISREG(st.st_mode)) { + /* When extending regular files, we get zeros from the OS */ + bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; + } ret = 0; fail: if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {