From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVFsU-0007as-Ac for qemu-devel@nongnu.org; Tue, 10 Mar 2015 04:51:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YVFsN-0007lL-Si for qemu-devel@nongnu.org; Tue, 10 Mar 2015 04:51:02 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:15205 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVFsM-0007ib-Ow for qemu-devel@nongnu.org; Tue, 10 Mar 2015 04:50:55 -0400 From: "Denis V. Lunev" Date: Tue, 10 Mar 2015 11:51:10 +0300 Message-Id: <1425977481-13317-17-git-send-email-den@openvz.org> In-Reply-To: <1425977481-13317-1-git-send-email-den@openvz.org> References: <1425977481-13317-1-git-send-email-den@openvz.org> Subject: [Qemu-devel] [PATCH 16/27] block/parallels: read parallels image header and BAT into single buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , "Denis V. Lunev" , qemu-devel@nongnu.org, Stefan Hajnoczi , Roman Kagan 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 CC: Roman Kagan CC: Kevin Wolf CC: Stefan Hajnoczi --- block/parallels.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/block/parallels.c b/block/parallels.c index a6d2dfd..ceed34d 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -57,6 +57,8 @@ typedef struct ParallelsHeader { typedef struct BDRVParallelsState { CoMutex lock; + ParallelsHeader *header; + uint32_t header_size; uint32_t *bat_bitmap; unsigned int bat_size; @@ -85,7 +87,7 @@ 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) { @@ -124,17 +126,25 @@ 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); qemu_co_mutex_init(&s->lock); return 0; @@ -143,7 +153,7 @@ fail_format: error_setg(errp, "Image not in Parallels format"); ret = -EINVAL; fail: - g_free(s->bat_bitmap); + qemu_vfree(s->header); return ret; } @@ -383,7 +393,7 @@ 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 = { -- 1.9.1