From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49622) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhlRD-0004zb-Uq for qemu-devel@nongnu.org; Tue, 06 May 2014 15:54:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WhlR7-0000om-P9 for qemu-devel@nongnu.org; Tue, 06 May 2014 15:54:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62275) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhlR7-0000oX-HB for qemu-devel@nongnu.org; Tue, 06 May 2014 15:53:57 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s46JruxM016017 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 6 May 2014 15:53:56 -0400 Message-ID: <53693DD0.40107@redhat.com> Date: Tue, 06 May 2014 21:53:52 +0200 From: Max Reitz MIME-Version: 1.0 References: <1399383018-17797-1-git-send-email-kwolf@redhat.com> In-Reply-To: <1399383018-17797-1-git-send-email-kwolf@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] block: Fix bdrv_is_allocated() for short backing files List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , qemu-devel@nongnu.org Cc: pbonzini@redhat.com, stefanha@redhat.com On 06.05.2014 15:30, Kevin Wolf wrote: > bdrv_is_allocated() shouldn't return true for sectors that are > unallocated, but after the end of a short backing file, even though > such sectors are (correctly) marked as containing zeros. > > Signed-off-by: Kevin Wolf > --- > block.c | 8 +++++--- > include/block/block.h | 11 +++++++---- > 2 files changed, 12 insertions(+), 7 deletions(-) > > diff --git a/block.c b/block.c > index c90c71a..d3a9906 100644 > --- a/block.c > +++ b/block.c > @@ -3883,6 +3883,10 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, > *pnum, pnum); > } > > + if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { > + ret |= BDRV_BLOCK_ALLOCATED; > + } > + Shouldn't BDRV_BLOCK_ALLOCATED be set in the !bs->drv->bdrv_co_get_block_status case as well? > if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) { > if (bdrv_unallocated_blocks_are_zero(bs)) { > ret |= BDRV_BLOCK_ZERO; > @@ -3959,9 +3963,7 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, > if (ret < 0) { > return ret; > } > - return > - (ret & BDRV_BLOCK_DATA) || > - ((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs)); > + return (ret & BDRV_BLOCK_ALLOCATED); > } > > /* > diff --git a/include/block/block.h b/include/block/block.h > index 2fda81c..ad4c7e8 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -116,6 +116,8 @@ typedef enum { > /* BDRV_BLOCK_DATA: data is read from bs->file or another file > * BDRV_BLOCK_ZERO: sectors read as zero > * BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data > + * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this > + * layer (as opposed to the backing file) I guess this is above BDRV_BLOCK_RAW (albeit having a greater value) because it is not only used internally? (to pick up on the topic of OCD :-P) Max > * BDRV_BLOCK_RAW: used internally to indicate that the request > * was answered by the raw driver and that one > * should look in bs->file directly. > @@ -137,10 +139,11 @@ typedef enum { > * f t f not allocated or unknown offset, read as zero > * f f f not allocated or unknown offset, read from backing_hd > */ > -#define BDRV_BLOCK_DATA 1 > -#define BDRV_BLOCK_ZERO 2 > -#define BDRV_BLOCK_OFFSET_VALID 4 > -#define BDRV_BLOCK_RAW 8 > +#define BDRV_BLOCK_DATA 0x01 > +#define BDRV_BLOCK_ZERO 0x02 > +#define BDRV_BLOCK_OFFSET_VALID 0x04 > +#define BDRV_BLOCK_RAW 0x08 > +#define BDRV_BLOCK_ALLOCATED 0x10 > #define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK > > typedef enum {