From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T2CQS-00031g-Q0 for qemu-devel@nongnu.org; Thu, 16 Aug 2012 22:36:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T2CQR-0005Wy-NZ for qemu-devel@nongnu.org; Thu, 16 Aug 2012 22:36:40 -0400 Received: from mail-gg0-f173.google.com ([209.85.161.173]:63358) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T2CQR-0005Ws-It for qemu-devel@nongnu.org; Thu, 16 Aug 2012 22:36:39 -0400 Received: by ggna5 with SMTP id a5so3589646ggn.4 for ; Thu, 16 Aug 2012 19:36:39 -0700 (PDT) From: Ronnie Sahlberg Date: Fri, 17 Aug 2012 12:36:20 +1000 Message-Id: <1345170981-7738-2-git-send-email-ronniesahlberg@gmail.com> In-Reply-To: <1345170981-7738-1-git-send-email-ronniesahlberg@gmail.com> References: <1345170981-7738-1-git-send-email-ronniesahlberg@gmail.com> Subject: [Qemu-devel] [PATCH 1/2] ISCSI: Set number of blocks to 0 for blank CDROM devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: kwolf@redhat.com, qemu-devel@nongnu.org, pbonzini@redhat.com Cc: Ronnie Sahlberg The number of blocks of the device is used to compute the device size in bdrv_getlength()/iscsi_getlength(). For MMC devices, the ReturnedLogicalBlockAddress in the READCAPACITY10 has a special meaning when it is 0. In this case it does not mean that LBA 0 is the last accessible LBA, and thus the device has 1 readable block, but instead it means that the disc is blank and there are no readable blocks. This change ensures that when the iSCSI LUN is loaded with a blank DVD-R disk or similar that bdrv_getlength() will return the correct size of the device as 0 bytes. Signed-off-by: Ronnie Sahlberg --- block/iscsi.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/block/iscsi.c b/block/iscsi.c index bb9cf82..fb420ea 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -717,7 +717,12 @@ iscsi_readcapacity10_cb(struct iscsi_context *iscsi, int status, } itask->iscsilun->block_size = rc10->block_size; - itask->iscsilun->num_blocks = rc10->lba + 1; + if (rc10->lba == 0) { + /* blank disk loaded */ + itask->iscsilun->num_blocks = 0; + } else { + itask->iscsilun->num_blocks = rc10->lba + 1; + } itask->bs->total_sectors = itask->iscsilun->num_blocks * itask->iscsilun->block_size / BDRV_SECTOR_SIZE ; -- 1.7.3.1