From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51979) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UO3x1-0002sI-By for qemu-devel@nongnu.org; Fri, 05 Apr 2013 06:33:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UO3x0-0004oi-6q for qemu-devel@nongnu.org; Fri, 05 Apr 2013 06:32:55 -0400 Received: from mail.avalus.com ([2001:41c8:10:1dd::10]:45531) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UO3wz-0004nx-Lx for qemu-devel@nongnu.org; Fri, 05 Apr 2013 06:32:53 -0400 From: Alex Bligh Date: Fri, 5 Apr 2013 11:32:48 +0100 Message-Id: <1365157969-23172-1-git-send-email-alex@alex.org.uk> In-Reply-To: References: Subject: [Qemu-devel] [PATCHv2 1/2] Xen PV backend (for qemu-upstream-4.2-testing): Move call to bdrv_new from blk_init to blk_connect List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefano Stabellini Cc: Ian Campbell , George Dunlap , Ian Jackson , qemu-devel@nongnu.org, xen-devel , Alex Bligh , Anthony Liguori , Paolo Bonzini This commit delays the point at which bdrv_new (and hence blk_open on the underlying device) is called from blk_init to blk_connect. This ensures that in an inbound live migrate, the block device is not opened until it has been closed at the other end. This is in preparation for supporting devices with open/close consistency without using O_DIRECT. This commit does NOT itself change O_DIRECT semantics. Signed-off-by: Alex Bligh --- hw/xen_disk.c | 69 ++++++++++++++++++++++++++++++++------------------------- 1 file changed, 39 insertions(+), 30 deletions(-) diff --git a/hw/xen_disk.c b/hw/xen_disk.c index a402ac8..3cecf8d 100644 --- a/hw/xen_disk.c +++ b/hw/xen_disk.c @@ -560,7 +560,7 @@ static void blk_alloc(struct XenDevice *xendev) static int blk_init(struct XenDevice *xendev) { struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); - int index, qflags, info = 0; + int info = 0; /* read xenstore entries */ if (blkdev->params == NULL) { @@ -603,18 +603,49 @@ static int blk_init(struct XenDevice *xendev) } /* read-only ? */ - qflags = BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO; - if (strcmp(blkdev->mode, "w") == 0) { - qflags |= BDRV_O_RDWR; - } else { + if (strcmp(blkdev->mode, "w")) { info |= VDISK_READONLY; } - + /* cdrom ? */ if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { info |= VDISK_CDROM; } + + blkdev->file_blk = BLOCK_SIZE; + + /* fill info + * blk_connect supplies sector-size and sectors + */ + xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1); + xenstore_write_be_int(&blkdev->xendev, "info", info); + return 0; + +out_error: + g_free(blkdev->params); + blkdev->params = NULL; + g_free(blkdev->mode); + blkdev->mode = NULL; + g_free(blkdev->type); + blkdev->type = NULL; + g_free(blkdev->dev); + blkdev->dev = NULL; + g_free(blkdev->devtype); + blkdev->devtype = NULL; + return -1; +} + +static int blk_connect(struct XenDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + int index, qflags; + /* read-only ? */ + qflags = BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO; + if (strcmp(blkdev->mode, "w") == 0) { + qflags |= BDRV_O_RDWR; + } + /* init qemu block driver */ index = (blkdev->xendev.dev - 202 * 256) / 16; blkdev->dinfo = drive_get(IF_XEN, 0, index); @@ -630,7 +661,7 @@ static int blk_init(struct XenDevice *xendev) } } if (!blkdev->bs) { - goto out_error; + return -1; } } else { /* setup via qemu cmdline -> already setup for us */ @@ -638,7 +669,6 @@ static int blk_init(struct XenDevice *xendev) blkdev->bs = blkdev->dinfo->bdrv; } bdrv_attach_dev_nofail(blkdev->bs, blkdev); - blkdev->file_blk = BLOCK_SIZE; blkdev->file_size = bdrv_getlength(blkdev->bs); if (blkdev->file_size < 0) { xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", @@ -652,31 +682,10 @@ static int blk_init(struct XenDevice *xendev) blkdev->type, blkdev->fileproto, blkdev->filename, blkdev->file_size, blkdev->file_size >> 20); - /* fill info */ - xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1); - xenstore_write_be_int(&blkdev->xendev, "info", info); + /* Fill in number of sector size and number of sectors */ xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk); xenstore_write_be_int(&blkdev->xendev, "sectors", blkdev->file_size / blkdev->file_blk); - return 0; - -out_error: - g_free(blkdev->params); - blkdev->params = NULL; - g_free(blkdev->mode); - blkdev->mode = NULL; - g_free(blkdev->type); - blkdev->type = NULL; - g_free(blkdev->dev); - blkdev->dev = NULL; - g_free(blkdev->devtype); - blkdev->devtype = NULL; - return -1; -} - -static int blk_connect(struct XenDevice *xendev) -{ - struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { return -1; -- 1.7.9.5