From patchwork Tue Apr 28 07:46:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 465408 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 5A5A014012C for ; Tue, 28 Apr 2015 17:54:10 +1000 (AEST) Received: from localhost ([::1]:59363 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yn0LI-0001KL-Cb for incoming@patchwork.ozlabs.org; Tue, 28 Apr 2015 03:54:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45002) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yn0Ev-0005mf-KM for qemu-devel@nongnu.org; Tue, 28 Apr 2015 03:47:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yn0Er-0004K1-53 for qemu-devel@nongnu.org; Tue, 28 Apr 2015 03:47:33 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:39900 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yn0Eq-0004Ja-HR for qemu-devel@nongnu.org; Tue, 28 Apr 2015 03:47:29 -0400 Received: from hades.sw.ru ([10.30.8.132]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id t3S7ktlw031473; Tue, 28 Apr 2015 10:47:26 +0300 (MSK) From: "Denis V. Lunev" To: Date: Tue, 28 Apr 2015 10:46:58 +0300 Message-Id: <1430207220-24458-26-git-send-email-den@openvz.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1430207220-24458-1-git-send-email-den@openvz.org> References: <1430207220-24458-1-git-send-email-den@openvz.org> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Cc: Kevin Wolf , "Denis V. Lunev" , qemu-devel@nongnu.org, Stefan Hajnoczi , Roman Kagan Subject: [Qemu-devel] [PATCH 25/27] block/parallels: add prealloc-mode and prealloc-size open paramemets X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This is preparational commit for tweaks in Parallels image expansion. The idea is that enlarge via truncate by one data block is slow. It would be much better to use fallocate via bdrv_write_zeroes and expand by some significant amount at once. Original idea with sequential file writing to the end of the file without fallocate/truncate would be slower than this approach if the image is expanded with several operations: - each image expanding means file metadata update, i.e. filesystem journal write. Truncate/write to newly truncated space update file metadata twice thus truncate removal helps. With fallocate call inside bdrv_write_zeroes file metadata is updated only once and this should happen infrequently thus this approach is the best one for the image expansion - tail writes are ordered, i.e. the guest IO queue could not be sent immediately to the host introducing additional IO delays This patch just adds proper parameters into BDRVParallelsState and performs options parsing in parallels_open. Signed-off-by: Denis V. Lunev CC: Roman Kagan CC: Kevin Wolf CC: Stefan Hajnoczi Reviewed-by: Roman Kagan Reviewed-by: Stefan Hajnoczi --- block/parallels.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 77 insertions(+), 6 deletions(-) diff --git a/block/parallels.c b/block/parallels.c index 05fe030..440938e 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -31,6 +31,7 @@ #include "block/block_int.h" #include "qemu/module.h" #include "qemu/bitmap.h" +#include "qapi/util.h" /**************************************************************/ @@ -56,6 +57,20 @@ typedef struct ParallelsHeader { char padding[12]; } QEMU_PACKED ParallelsHeader; + +typedef enum ParallelsPreallocMode { + PRL_PREALLOC_MODE_FALLOCATE = 0, + PRL_PREALLOC_MODE_TRUNCATE = 1, + PRL_PREALLOC_MODE_MAX = 2, +} ParallelsPreallocMode; + +static const char *prealloc_mode_lookup[] = { + "falloc", + "truncate", + NULL, +}; + + typedef struct BDRVParallelsState { /** Locking is conservative, the lock protects * - image file extending (truncate, fallocate) @@ -73,14 +88,40 @@ typedef struct BDRVParallelsState { uint32_t *bat_bitmap; unsigned int bat_size; + uint64_t prealloc_size; + ParallelsPreallocMode prealloc_mode; + unsigned int tracks; unsigned int off_multiplier; - - bool has_truncate; } BDRVParallelsState; +#define PARALLELS_OPT_PREALLOC_MODE "prealloc-mode" +#define PARALLELS_OPT_PREALLOC_SIZE "prealloc-size" + +static QemuOptsList parallels_runtime_opts = { + .name = "parallels", + .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head), + .desc = { + { + .name = PARALLELS_OPT_PREALLOC_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Preallocation size on image expansion", + .def_value_str = "128MiB", + }, + { + .name = PARALLELS_OPT_PREALLOC_MODE, + .type = QEMU_OPT_STRING, + .help = "Preallocation mode on image expansion " + "(allowed values: falloc, truncate)", + .def_value_str = "falloc", + }, + { /* end of list */ }, + }, +}; + + static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx) { return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier; @@ -159,7 +200,7 @@ static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num) } pos = bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS; - if (s->has_truncate) { + if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) { ret = bdrv_truncate(bs->file, (pos + s->tracks) << BDRV_SECTOR_BITS); } else { ret = bdrv_write_zeroes(bs->file, pos, s->tracks, 0); @@ -509,6 +550,9 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, BDRVParallelsState *s = bs->opaque; ParallelsHeader ph; int ret, size; + QemuOpts *opts = NULL; + Error *local_err = NULL; + char *buf; ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph)); if (ret < 0) { @@ -567,9 +611,6 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, } 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; - if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) { /* Image was not closed correctly. The check is mandatory */ s->header_unclean = true; @@ -581,6 +622,31 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, } } + opts = qemu_opts_create(¶llels_runtime_opts, NULL, 0, &local_err); + if (local_err != NULL) { + goto fail_options; + } + + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err != NULL) { + goto fail_options; + } + + s->prealloc_size = + qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0); + s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS); + buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE); + s->prealloc_mode = qapi_enum_parse(prealloc_mode_lookup, buf, + PRL_PREALLOC_MODE_MAX, PRL_PREALLOC_MODE_FALLOCATE, &local_err); + g_free(buf); + if (local_err != NULL) { + goto fail_options; + } + if (!bdrv_has_zero_init(bs->file) || + bdrv_truncate(bs->file, bdrv_getlength(bs->file)) != 0) { + s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE; + } + if (flags & BDRV_O_RDWR) { s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC); ret = parallels_update_header(bs); @@ -602,6 +668,11 @@ fail_format: fail: qemu_vfree(s->header); return ret; + +fail_options: + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; }