From patchwork Tue Jun 5 14:06:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 925493 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 410Ycx170Rz9s0x for ; Wed, 6 Jun 2018 00:11:13 +1000 (AEST) Received: from localhost ([::1]:47023 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQCg2-0008Qz-PD for incoming@patchwork.ozlabs.org; Tue, 05 Jun 2018 10:11:10 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37545) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQCcA-0004nV-55 for qemu-devel@nongnu.org; Tue, 05 Jun 2018 10:07:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQCc8-0005hu-RO for qemu-devel@nongnu.org; Tue, 05 Jun 2018 10:07:10 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35738 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQCbv-0005d7-In; Tue, 05 Jun 2018 10:06:55 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E417DEB6ED; Tue, 5 Jun 2018 14:06:54 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-89.pek2.redhat.com [10.72.12.89]) by smtp.corp.redhat.com (Postfix) with ESMTP id 37B3E63A6B; Tue, 5 Jun 2018 14:06:50 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 5 Jun 2018 22:06:31 +0800 Message-Id: <20180605140631.4696-3-famz@redhat.com> In-Reply-To: <20180605140631.4696-1-famz@redhat.com> References: <20180605140631.4696-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 05 Jun 2018 14:06:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 05 Jun 2018 14:06:54 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v3 2/2] backup: Use copy offloading X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Jeff Cody , Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The implementation is similar to the 'qemu-img convert'. In the beginning of the job, offloaded copy is attempted. If it fails, further I/O will go through the existing bounce buffer code path. Signed-off-by: Fam Zheng --- block/backup.c | 150 ++++++++++++++++++++++++++++++++------------- block/trace-events | 1 + 2 files changed, 110 insertions(+), 41 deletions(-) diff --git a/block/backup.c b/block/backup.c index 4e228e959b..0dabdc9693 100644 --- a/block/backup.c +++ b/block/backup.c @@ -45,6 +45,8 @@ typedef struct BackupBlockJob { QLIST_HEAD(, CowRequest) inflight_reqs; HBitmap *copy_bitmap; + bool use_copy_range; + int64_t copy_range_size; } BackupBlockJob; static const BlockJobDriver backup_job_driver; @@ -86,19 +88,101 @@ static void cow_request_end(CowRequest *req) qemu_co_queue_restart_all(&req->wait_queue); } +/* Copy range to target with a bounce buffer and return the bytes copied. If + * error occured, return a negative error number */ +static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, + int64_t start, + int64_t end, + bool is_write_notifier, + bool *error_is_read, + void **bounce_buffer) +{ + int ret; + struct iovec iov; + QEMUIOVector qiov; + BlockBackend *blk = job->common.blk; + int nbytes; + + hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1); + nbytes = MIN(job->cluster_size, job->len - start); + if (!*bounce_buffer) { + *bounce_buffer = blk_blockalign(blk, job->cluster_size); + } + iov.iov_base = *bounce_buffer; + iov.iov_len = nbytes; + qemu_iovec_init_external(&qiov, &iov, 1); + + ret = blk_co_preadv(blk, start, qiov.size, &qiov, + is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0); + if (ret < 0) { + trace_backup_do_cow_read_fail(job, start, ret); + if (error_is_read) { + *error_is_read = true; + } + goto fail; + } + + if (qemu_iovec_is_zero(&qiov)) { + ret = blk_co_pwrite_zeroes(job->target, start, + qiov.size, BDRV_REQ_MAY_UNMAP); + } else { + ret = blk_co_pwritev(job->target, start, + qiov.size, &qiov, + job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0); + } + if (ret < 0) { + trace_backup_do_cow_write_fail(job, start, ret); + if (error_is_read) { + *error_is_read = false; + } + goto fail; + } + + return nbytes; +fail: + hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1); + return ret; + +} + +/* Copy range to target and return the bytes copied. If error occured, return a + * negative error number. */ +static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job, + int64_t start, + int64_t end, + bool is_write_notifier) +{ + int ret; + int nr_clusters; + BlockBackend *blk = job->common.blk; + int nbytes; + + assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size)); + nbytes = MIN(job->copy_range_size, end - start); + nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size); + hbitmap_reset(job->copy_bitmap, start / job->cluster_size, + nr_clusters); + ret = blk_co_copy_range(blk, start, job->target, start, nbytes, + is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0); + if (ret < 0) { + trace_backup_do_cow_copy_range_fail(job, start, ret); + hbitmap_set(job->copy_bitmap, start / job->cluster_size, + nr_clusters); + return ret; + } + + return nbytes; +} + static int coroutine_fn backup_do_cow(BackupBlockJob *job, int64_t offset, uint64_t bytes, bool *error_is_read, bool is_write_notifier) { - BlockBackend *blk = job->common.blk; CowRequest cow_request; - struct iovec iov; - QEMUIOVector bounce_qiov; - void *bounce_buffer = NULL; int ret = 0; int64_t start, end; /* bytes */ - int n; /* bytes */ + void *bounce_buffer = NULL; qemu_co_rwlock_rdlock(&job->flush_rwlock); @@ -110,60 +194,38 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job, wait_for_overlapping_requests(job, start, end); cow_request_begin(&cow_request, job, start, end); - for (; start < end; start += job->cluster_size) { + while (start < end) { if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) { trace_backup_do_cow_skip(job, start); + start += job->cluster_size; continue; /* already copied */ } - hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1); trace_backup_do_cow_process(job, start); - n = MIN(job->cluster_size, job->len - start); - - if (!bounce_buffer) { - bounce_buffer = blk_blockalign(blk, job->cluster_size); - } - iov.iov_base = bounce_buffer; - iov.iov_len = n; - qemu_iovec_init_external(&bounce_qiov, &iov, 1); - - ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov, - is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0); - if (ret < 0) { - trace_backup_do_cow_read_fail(job, start, ret); - if (error_is_read) { - *error_is_read = true; + if (job->use_copy_range) { + ret = backup_cow_with_offload(job, start, end, is_write_notifier); + if (ret < 0) { + job->use_copy_range = false; } - hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1); - goto out; } - - if (buffer_is_zero(iov.iov_base, iov.iov_len)) { - ret = blk_co_pwrite_zeroes(job->target, start, - bounce_qiov.size, BDRV_REQ_MAY_UNMAP); - } else { - ret = blk_co_pwritev(job->target, start, - bounce_qiov.size, &bounce_qiov, - job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0); + if (!job->use_copy_range) { + ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier, + error_is_read, &bounce_buffer); } if (ret < 0) { - trace_backup_do_cow_write_fail(job, start, ret); - if (error_is_read) { - *error_is_read = false; - } - hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1); - goto out; + break; } /* Publish progress, guest I/O counts as progress too. Note that the * offset field is an opaque progress value, it is not a disk offset. */ - job->bytes_read += n; - job_progress_update(&job->common.job, n); + start += ret; + job->bytes_read += ret; + job_progress_update(&job->common.job, ret); + ret = 0; } -out: if (bounce_buffer) { qemu_vfree(bounce_buffer); } @@ -665,6 +727,12 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, } else { job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size); } + job->use_copy_range = true; + job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk), + blk_get_max_transfer(job->target)); + job->copy_range_size = MAX(job->cluster_size, + QEMU_ALIGN_UP(job->copy_range_size, + job->cluster_size)); /* Required permissions are already taken with target's blk_new() */ block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL, diff --git a/block/trace-events b/block/trace-events index 2d59b53fd3..c35287b48a 100644 --- a/block/trace-events +++ b/block/trace-events @@ -42,6 +42,7 @@ backup_do_cow_skip(void *job, int64_t start) "job %p start %"PRId64 backup_do_cow_process(void *job, int64_t start) "job %p start %"PRId64 backup_do_cow_read_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d" backup_do_cow_write_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d" +backup_do_cow_copy_range_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d" # blockdev.c qmp_block_job_cancel(void *job) "job %p"