From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56829) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yvir3-0004Jf-Mn for qemu-devel@nongnu.org; Fri, 22 May 2015 05:03:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yviqx-0004oA-3y for qemu-devel@nongnu.org; Fri, 22 May 2015 05:02:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42281) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yviqw-0004nx-U6 for qemu-devel@nongnu.org; Fri, 22 May 2015 05:02:51 -0400 From: Stefan Hajnoczi Date: Fri, 22 May 2015 10:01:49 +0100 Message-Id: <1432285330-13994-18-git-send-email-stefanha@redhat.com> In-Reply-To: <1432285330-13994-1-git-send-email-stefanha@redhat.com> References: <1432285330-13994-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 17/38] block/parallels: read parallels image header and BAT into single buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Peter Maydell , Roman Kagan , Stefan Hajnoczi , "Denis V. Lunev" From: "Denis V. Lunev" This metadata cache would allow to properly batch BAT updates to disk in next patches. These updates will be properly aligned to avoid read-modify-write transactions on block level. Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan Reviewed-by: Stefan Hajnoczi Signed-off-by: Roman Kagan Message-id: 1430207220-24458-18-git-send-email-den@openvz.org CC: Kevin Wolf Signed-off-by: Stefan Hajnoczi --- block/parallels.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/block/parallels.c b/block/parallels.c index 431adf1..f8a9981 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -61,6 +61,8 @@ typedef struct BDRVParallelsState { */ CoMutex lock; + ParallelsHeader *header; + uint32_t header_size; uint32_t *bat_bitmap; unsigned int bat_size; @@ -91,7 +93,7 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, { BDRVParallelsState *s = bs->opaque; ParallelsHeader ph; - int ret; + int ret, size; ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph)); if (ret < 0) { @@ -130,17 +132,25 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, ret = -EFBIG; goto fail; } - s->bat_bitmap = g_try_new(uint32_t, s->bat_size); - if (s->bat_size && s->bat_bitmap == NULL) { + + size = sizeof(ParallelsHeader) + sizeof(uint32_t) * s->bat_size; + s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file)); + s->header = qemu_try_blockalign(bs->file, s->header_size); + if (s->header == NULL) { ret = -ENOMEM; goto fail; } + if (le32_to_cpu(ph.data_off) < s->header_size) { + /* there is not enough unused space to fit to block align between BAT + and actual data. We can't avoid read-modify-write... */ + s->header_size = size; + } - ret = bdrv_pread(bs->file, sizeof(ParallelsHeader), - s->bat_bitmap, s->bat_size * sizeof(uint32_t)); + ret = bdrv_pread(bs->file, 0, s->header, s->header_size); if (ret < 0) { goto fail; } + s->bat_bitmap = (uint32_t *)(s->header + 1); s->has_truncate = bdrv_has_zero_init(bs->file) && bdrv_truncate(bs->file, bdrv_getlength(bs->file)) == 0; @@ -152,7 +162,7 @@ fail_format: error_setg(errp, "Image not in Parallels format"); ret = -EINVAL; fail: - g_free(s->bat_bitmap); + qemu_vfree(s->header); return ret; } @@ -400,7 +410,7 @@ exit: static void parallels_close(BlockDriverState *bs) { BDRVParallelsState *s = bs->opaque; - g_free(s->bat_bitmap); + qemu_vfree(s->header); } static QemuOptsList parallels_create_opts = { -- 2.1.0