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{
    "id": 749668,
    "url": "http://patchwork.ozlabs.org/api/patches/749668/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170411222945.11741-15-eblake@redhat.com/",
    "project": {
        "id": 14,
        "url": "http://patchwork.ozlabs.org/api/projects/14/?format=api",
        "name": "QEMU Development",
        "link_name": "qemu-devel",
        "list_id": "qemu-devel.nongnu.org",
        "list_email": "qemu-devel@nongnu.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": "",
        "list_archive_url": "",
        "list_archive_url_format": "",
        "commit_url_format": ""
    },
    "msgid": "<20170411222945.11741-15-eblake@redhat.com>",
    "list_archive_url": null,
    "date": "2017-04-11T22:29:42",
    "name": "[14/17] backup: Switch backup_do_cow() to byte-based",
    "commit_ref": null,
    "pull_url": null,
    "state": "new",
    "archived": false,
    "hash": "ff2cdbc1fb7c928c534f4bc6de9f0de842e4ce60",
    "submitter": {
        "id": 6591,
        "url": "http://patchwork.ozlabs.org/api/people/6591/?format=api",
        "name": "Eric Blake",
        "email": "eblake@redhat.com"
    },
    "delegate": null,
    "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170411222945.11741-15-eblake@redhat.com/mbox/",
    "series": [],
    "comments": "http://patchwork.ozlabs.org/api/patches/749668/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/749668/checks/",
    "tags": {},
    "related": [],
    "headers": {
        "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>",
        "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])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3w2hwm4Qp2z9sNd\n\tfor <incoming@patchwork.ozlabs.org>;\n\tWed, 12 Apr 2017 08:46:00 +1000 (AEST)",
            "from localhost ([::1]:41414 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\n\tid 1cy4Xu-0002Cd-5Z\n\tfor incoming@patchwork.ozlabs.org; Tue, 11 Apr 2017 18:45:58 -0400",
            "from eggs.gnu.org ([2001:4830:134:3::10]:40380)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <eblake@redhat.com>) id 1cy4Ii-0006Nk-Rx\n\tfor qemu-devel@nongnu.org; Tue, 11 Apr 2017 18:30:18 -0400",
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            "from red.redhat.com (ovpn-122-61.rdu2.redhat.com [10.10.122.61])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id C1E5518EFF;\n\tTue, 11 Apr 2017 22:30:09 +0000 (UTC)"
        ],
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        ],
        "DKIM-Filter": "OpenDKIM Filter v2.11.0 mx1.redhat.com C643F61D19",
        "From": "Eric Blake <eblake@redhat.com>",
        "To": "qemu-devel@nongnu.org",
        "Date": "Tue, 11 Apr 2017 17:29:42 -0500",
        "Message-Id": "<20170411222945.11741-15-eblake@redhat.com>",
        "In-Reply-To": "<20170411222945.11741-1-eblake@redhat.com>",
        "References": "<20170411222945.11741-1-eblake@redhat.com>",
        "X-Scanned-By": "MIMEDefang 2.79 on 10.5.11.11",
        "X-Greylist": "Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.39]);\n\tTue, 11 Apr 2017 22:30:11 +0000 (UTC)",
        "X-detected-operating-system": "by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]",
        "X-Received-From": "209.132.183.28",
        "Subject": "[Qemu-devel] [PATCH 14/17] backup: Switch backup_do_cow() to\n\tbyte-based",
        "X-BeenThere": "qemu-devel@nongnu.org",
        "X-Mailman-Version": "2.1.21",
        "Precedence": "list",
        "List-Id": "<qemu-devel.nongnu.org>",
        "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>",
        "List-Archive": "<http://lists.nongnu.org/archive/html/qemu-devel/>",
        "List-Post": "<mailto:qemu-devel@nongnu.org>",
        "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>",
        "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>",
        "Cc": "kwolf@redhat.com, Jeff Cody <jcody@redhat.com>, qemu-block@nongnu.org,\n\tMax Reitz <mreitz@redhat.com>",
        "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org",
        "Sender": "\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"
    },
    "content": "We are gradually converting to byte-based interfaces, as they are\neasier to reason about than sector-based.  Convert another internal\nfunction (no semantic change).\n\nSigned-off-by: Eric Blake <eblake@redhat.com>\n---\n block/backup.c | 62 ++++++++++++++++++++++++----------------------------------\n 1 file changed, 26 insertions(+), 36 deletions(-)",
    "diff": "diff --git a/block/backup.c b/block/backup.c\nindex 0502c1a..0e87b22 100644\n--- a/block/backup.c\n+++ b/block/backup.c\n@@ -91,7 +91,7 @@ static void cow_request_end(CowRequest *req)\n }\n\n static int coroutine_fn backup_do_cow(BackupBlockJob *job,\n-                                      int64_t sector_num, int nb_sectors,\n+                                      int64_t offset, uint64_t bytes,\n                                       bool *error_is_read,\n                                       bool is_write_notifier)\n {\n@@ -101,34 +101,28 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,\n     QEMUIOVector bounce_qiov;\n     void *bounce_buffer = NULL;\n     int ret = 0;\n-    int64_t sectors_per_cluster = cluster_size_sectors(job);\n-    int64_t start, end; /* clusters */\n+    int64_t start, end; /* bytes */\n     int n; /* bytes */\n\n     qemu_co_rwlock_rdlock(&job->flush_rwlock);\n\n-    start = sector_num / sectors_per_cluster;\n-    end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);\n+    start = QEMU_ALIGN_DOWN(offset, job->cluster_size);\n+    end = QEMU_ALIGN_UP(bytes + offset, job->cluster_size);\n\n-    trace_backup_do_cow_enter(job, start * job->cluster_size,\n-                              sector_num * BDRV_SECTOR_SIZE,\n-                              nb_sectors * BDRV_SECTOR_SIZE);\n+    trace_backup_do_cow_enter(job, start, offset, bytes);\n\n-    wait_for_overlapping_requests(job, start * job->cluster_size,\n-                                  end * job->cluster_size);\n-    cow_request_begin(&cow_request, job, start * job->cluster_size,\n-                      end * job->cluster_size);\n+    wait_for_overlapping_requests(job, start, end);\n+    cow_request_begin(&cow_request, job, start, end);\n\n-    for (; start < end; start++) {\n-        if (test_bit(start, job->done_bitmap)) {\n-            trace_backup_do_cow_skip(job, start * job->cluster_size);\n+    for (; start < end; start += job->cluster_size) {\n+        if (test_bit(start / job->cluster_size, job->done_bitmap)) {\n+            trace_backup_do_cow_skip(job, start);\n             continue; /* already copied */\n         }\n\n-        trace_backup_do_cow_process(job, start * job->cluster_size);\n+        trace_backup_do_cow_process(job, start);\n\n-        n = MIN(job->cluster_size,\n-                job->common.len - start * job->cluster_size);\n+        n = MIN(job->cluster_size, job->common.len - start);\n\n         if (!bounce_buffer) {\n             bounce_buffer = blk_blockalign(blk, job->cluster_size);\n@@ -137,11 +131,10 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,\n         iov.iov_len = n;\n         qemu_iovec_init_external(&bounce_qiov, &iov, 1);\n\n-        ret = blk_co_preadv(blk, start * job->cluster_size,\n-                            bounce_qiov.size, &bounce_qiov,\n+        ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov,\n                             is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);\n         if (ret < 0) {\n-            trace_backup_do_cow_read_fail(job, start * job->cluster_size, ret);\n+            trace_backup_do_cow_read_fail(job, start, ret);\n             if (error_is_read) {\n                 *error_is_read = true;\n             }\n@@ -149,22 +142,22 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,\n         }\n\n         if (buffer_is_zero(iov.iov_base, iov.iov_len)) {\n-            ret = blk_co_pwrite_zeroes(job->target, start * job->cluster_size,\n+            ret = blk_co_pwrite_zeroes(job->target, start,\n                                        bounce_qiov.size, BDRV_REQ_MAY_UNMAP);\n         } else {\n-            ret = blk_co_pwritev(job->target, start * job->cluster_size,\n+            ret = blk_co_pwritev(job->target, start,\n                                  bounce_qiov.size, &bounce_qiov,\n                                  job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);\n         }\n         if (ret < 0) {\n-            trace_backup_do_cow_write_fail(job, start * job->cluster_size, ret);\n+            trace_backup_do_cow_write_fail(job, start, ret);\n             if (error_is_read) {\n                 *error_is_read = false;\n             }\n             goto out;\n         }\n\n-        set_bit(start, job->done_bitmap);\n+        set_bit(start / job->cluster_size, job->done_bitmap);\n\n         /* Publish progress, guest I/O counts as progress too.  Note that the\n          * offset field is an opaque progress value, it is not a disk offset.\n@@ -180,8 +173,7 @@ out:\n\n     cow_request_end(&cow_request);\n\n-    trace_backup_do_cow_return(job, sector_num * BDRV_SECTOR_SIZE,\n-                               nb_sectors * BDRV_SECTOR_SIZE, ret);\n+    trace_backup_do_cow_return(job, offset, bytes, ret);\n\n     qemu_co_rwlock_unlock(&job->flush_rwlock);\n\n@@ -194,14 +186,12 @@ static int coroutine_fn backup_before_write_notify(\n {\n     BackupBlockJob *job = container_of(notifier, BackupBlockJob, before_write);\n     BdrvTrackedRequest *req = opaque;\n-    int64_t sector_num = req->offset >> BDRV_SECTOR_BITS;\n-    int nb_sectors = req->bytes >> BDRV_SECTOR_BITS;\n\n     assert(req->bs == blk_bs(job->common.blk));\n-    assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0);\n-    assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0);\n+    assert(QEMU_IS_ALIGNED(req->offset, BDRV_SECTOR_SIZE));\n+    assert(QEMU_IS_ALIGNED(req->bytes, BDRV_SECTOR_SIZE));\n\n-    return backup_do_cow(job, sector_num, nb_sectors, NULL, true);\n+    return backup_do_cow(job, req->offset, req->bytes, NULL, true);\n }\n\n static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp)\n@@ -406,8 +396,8 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)\n                 if (yield_and_check(job)) {\n                     goto out;\n                 }\n-                ret = backup_do_cow(job, cluster * sectors_per_cluster,\n-                                    sectors_per_cluster, &error_is_read,\n+                ret = backup_do_cow(job, cluster * job->cluster_size,\n+                                    job->cluster_size, &error_is_read,\n                                     false);\n                 if ((ret < 0) &&\n                     backup_error_action(job, error_is_read, -ret) ==\n@@ -509,8 +499,8 @@ static void coroutine_fn backup_run(void *opaque)\n             if (alloced < 0) {\n                 ret = alloced;\n             } else {\n-                ret = backup_do_cow(job, start * sectors_per_cluster,\n-                                    sectors_per_cluster, &error_is_read,\n+                ret = backup_do_cow(job, start * job->cluster_size,\n+                                    job->cluster_size, &error_is_read,\n                                     false);\n             }\n             if (ret < 0) {\n",
    "prefixes": [
        "14/17"
    ]
}