From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NVCbm-0000zn-Ia for qemu-devel@nongnu.org; Wed, 13 Jan 2010 18:26:38 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NVCbi-0000yU-Np for qemu-devel@nongnu.org; Wed, 13 Jan 2010 18:26:38 -0500 Received: from [199.232.76.173] (port=57783 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NVCbi-0000yP-IZ for qemu-devel@nongnu.org; Wed, 13 Jan 2010 18:26:34 -0500 Received: from qw-out-1920.google.com ([74.125.92.148]:8876) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NVCbi-0001Ee-AV for qemu-devel@nongnu.org; Wed, 13 Jan 2010 18:26:34 -0500 Received: by qw-out-1920.google.com with SMTP id 14so447846qwa.4 for ; Wed, 13 Jan 2010 15:26:33 -0800 (PST) Message-ID: <4B4E56A7.4040901@codemonkey.ws> Date: Wed, 13 Jan 2010 17:26:31 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH v4 1/3] block: Introduce BDRV_O_NO_BACKING References: <1263297318-10912-1-git-send-email-kwolf@redhat.com> <1263297318-10912-2-git-send-email-kwolf@redhat.com> In-Reply-To: <1263297318-10912-2-git-send-email-kwolf@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org On 01/12/2010 05:55 AM, Kevin Wolf wrote: > If an image references a backing file that doesn't exist, qemu-img info fails > to open this image. Exactly in this case the info would be valuable, though: > the user might want to find out which file is missing. > > This patch introduces a BDRV_O_NO_BACKING flag to ignore the backing file when > opening the image. qemu-img info is the first user and provides info now even > if the backing file is invalid. > > Signed-off-by: Kevin Wolf > Applied all. Thanks. Regards, Anthony Liguori > --- > block.c | 4 ++-- > block.h | 1 + > qemu-img.c | 2 +- > 3 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/block.c b/block.c > index 30ae2b1..994109e 100644 > --- a/block.c > +++ b/block.c > @@ -477,7 +477,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags, > unlink(filename); > } > #endif > - if (bs->backing_file[0] != '\0') { > + if ((flags& BDRV_O_NO_BACKING) == 0&& bs->backing_file[0] != '\0') { > /* if there is a backing file, use it */ > BlockDriver *back_drv = NULL; > bs->backing_hd = bdrv_new(""); > @@ -1352,7 +1352,7 @@ const char *bdrv_get_encrypted_filename(BlockDriverState *bs) > void bdrv_get_backing_filename(BlockDriverState *bs, > char *filename, int filename_size) > { > - if (!bs->backing_hd) { > + if (!bs->backing_file) { > pstrcpy(filename, filename_size, ""); > } else { > pstrcpy(filename, filename_size, bs->backing_file); > diff --git a/block.h b/block.h > index fa51ddf..f660d5f 100644 > --- a/block.h > +++ b/block.h > @@ -39,6 +39,7 @@ typedef struct QEMUSnapshotInfo { > #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */ > #define BDRV_O_CACHE_WB 0x0040 /* use write-back caching */ > #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ > +#define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ > > #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB) > > diff --git a/qemu-img.c b/qemu-img.c > index 1d97f2e..5ad88bf 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -884,7 +884,7 @@ static int img_info(int argc, char **argv) > } else { > drv = NULL; > } > - if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv)< 0) { > + if (bdrv_open2(bs, filename, BRDV_O_FLAGS | BDRV_O_NO_BACKING, drv)< 0) { > error("Could not open '%s'", filename); > } > bdrv_get_format(bs, fmt_name, sizeof(fmt_name)); >