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GET /api/patches/813845/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
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Vary: Accept

{
    "id": 813845,
    "url": "http://patchwork.ozlabs.org/api/patches/813845/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170914144032.14945-6-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": "<20170914144032.14945-6-eblake@redhat.com>",
    "list_archive_url": null,
    "date": "2017-09-14T14:40:17",
    "name": "[v3,05/20] iscsi: Switch cluster_sectors to byte-based",
    "commit_ref": null,
    "pull_url": null,
    "state": "new",
    "archived": false,
    "hash": "55b43f2b205586a61c087a138e22367d47334bee",
    "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/20170914144032.14945-6-eblake@redhat.com/mbox/",
    "series": [
        {
            "id": 3114,
            "url": "http://patchwork.ozlabs.org/api/series/3114/?format=api",
            "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=3114",
            "date": "2017-09-14T14:40:12",
            "name": "add byte-based block_status driver callbacks",
            "version": 3,
            "mbox": "http://patchwork.ozlabs.org/series/3114/mbox/"
        }
    ],
    "comments": "http://patchwork.ozlabs.org/api/patches/813845/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/813845/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",
        "Authentication-Results": [
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            "ext-mx09.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@redhat.com"
        ],
        "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 3xtLpB6JZ8z9sPk\n\tfor <incoming@patchwork.ozlabs.org>;\n\tFri, 15 Sep 2017 00:41:54 +1000 (AEST)",
            "from localhost ([::1]:48171 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 1dsVKy-0005jQ-Tk\n\tfor incoming@patchwork.ozlabs.org; Thu, 14 Sep 2017 10:41:52 -0400",
            "from eggs.gnu.org ([2001:4830:134:3::10]:46324)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <eblake@redhat.com>) id 1dsVK7-0005cZ-Vc\n\tfor qemu-devel@nongnu.org; Thu, 14 Sep 2017 10:41:01 -0400",
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            "from mx1.redhat.com ([209.132.183.28]:58548)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from <eblake@redhat.com>)\n\tid 1dsVK0-0002N6-Hb; Thu, 14 Sep 2017 10:40:52 -0400",
            "from smtp.corp.redhat.com\n\t(int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id 914BD4E33A;\n\tThu, 14 Sep 2017 14:40:51 +0000 (UTC)",
            "from red.redhat.com (ovpn-123-70.rdu2.redhat.com [10.10.123.70])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 7ACA360841;\n\tThu, 14 Sep 2017 14:40:49 +0000 (UTC)"
        ],
        "DMARC-Filter": "OpenDMARC Filter v1.3.2 mx1.redhat.com 914BD4E33A",
        "From": "Eric Blake <eblake@redhat.com>",
        "To": "qemu-devel@nongnu.org",
        "Date": "Thu, 14 Sep 2017 09:40:17 -0500",
        "Message-Id": "<20170914144032.14945-6-eblake@redhat.com>",
        "In-Reply-To": "<20170914144032.14945-1-eblake@redhat.com>",
        "References": "<20170914144032.14945-1-eblake@redhat.com>",
        "X-Scanned-By": "MIMEDefang 2.79 on 10.5.11.13",
        "X-Greylist": "Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.38]);\n\tThu, 14 Sep 2017 14:40:51 +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 v3 05/20] iscsi: Switch cluster_sectors 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, famz@redhat.com, qemu-block@nongnu.org,\n\tPeter Lieven <pl@kamp.de>, Max Reitz <mreitz@redhat.com>,\n\tRonnie Sahlberg <ronniesahlberg@gmail.com>,\n\tPaolo Bonzini <pbonzini@redhat.com>, jsnow@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 all uses of\nthe cluster size in sectors, along with adding assertions that we\nare not dividing by zero.\n\nSigned-off-by: Eric Blake <eblake@redhat.com>\n\n---\nv2: no change\n---\n block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++---------------------\n 1 file changed, 35 insertions(+), 21 deletions(-)",
    "diff": "diff --git a/block/iscsi.c b/block/iscsi.c\nindex 8b47d30dcc..08f43ddb0c 100644\n--- a/block/iscsi.c\n+++ b/block/iscsi.c\n@@ -79,7 +79,7 @@ typedef struct IscsiLun {\n     unsigned long *allocmap;\n     unsigned long *allocmap_valid;\n     long allocmap_size;\n-    int cluster_sectors;\n+    int cluster_size;\n     bool use_16_for_rw;\n     bool write_protected;\n     bool lbpme;\n@@ -460,9 +460,10 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)\n {\n     iscsi_allocmap_free(iscsilun);\n\n+    assert(iscsilun->cluster_size);\n     iscsilun->allocmap_size =\n-        DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun),\n-                     iscsilun->cluster_sectors);\n+        DIV_ROUND_UP(iscsilun->num_blocks * iscsilun->block_size,\n+                     iscsilun->cluster_size);\n\n     iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size);\n     if (!iscsilun->allocmap) {\n@@ -470,7 +471,7 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)\n     }\n\n     if (open_flags & BDRV_O_NOCACHE) {\n-        /* in case that cache.direct = on all allocmap entries are\n+        /* when cache.direct = on all allocmap entries are\n          * treated as invalid to force a relookup of the block\n          * status on every read request */\n         return 0;\n@@ -491,17 +492,19 @@ iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,\n                       int nb_sectors, bool allocated, bool valid)\n {\n     int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;\n+    int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;\n\n     if (iscsilun->allocmap == NULL) {\n         return;\n     }\n     /* expand to entirely contain all affected clusters */\n-    cl_num_expanded = sector_num / iscsilun->cluster_sectors;\n+    assert(cluster_sectors);\n+    cl_num_expanded = sector_num / cluster_sectors;\n     nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,\n-                                   iscsilun->cluster_sectors) - cl_num_expanded;\n+                                   cluster_sectors) - cl_num_expanded;\n     /* shrink to touch only completely contained clusters */\n-    cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);\n-    nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors\n+    cl_num_shrunk = DIV_ROUND_UP(sector_num, cluster_sectors);\n+    nb_cls_shrunk = (sector_num + nb_sectors) / cluster_sectors\n                       - cl_num_shrunk;\n     if (allocated) {\n         bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);\n@@ -565,9 +568,12 @@ iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num,\n     if (iscsilun->allocmap == NULL) {\n         return true;\n     }\n-    size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);\n+    assert(iscsilun->cluster_size);\n+    size = DIV_ROUND_UP(sector_num + nb_sectors,\n+                        iscsilun->cluster_size >> BDRV_SECTOR_BITS);\n     return !(find_next_bit(iscsilun->allocmap, size,\n-                           sector_num / iscsilun->cluster_sectors) == size);\n+                           sector_num * BDRV_SECTOR_SIZE /\n+                           iscsilun->cluster_size) == size);\n }\n\n static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,\n@@ -577,9 +583,12 @@ static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,\n     if (iscsilun->allocmap_valid == NULL) {\n         return false;\n     }\n-    size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);\n+    assert(iscsilun->cluster_size);\n+    size = DIV_ROUND_UP(sector_num + nb_sectors,\n+                        iscsilun->cluster_size >> BDRV_SECTOR_BITS);\n     return (find_next_zero_bit(iscsilun->allocmap_valid, size,\n-                               sector_num / iscsilun->cluster_sectors) == size);\n+                               sector_num * BDRV_SECTOR_SIZE /\n+                               iscsilun->cluster_size) == size);\n }\n\n static int coroutine_fn\n@@ -814,16 +823,21 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,\n         BlockDriverState *file;\n         /* check the block status from the beginning of the cluster\n          * containing the start sector */\n-        int64_t ret = iscsi_co_get_block_status(bs,\n-                          sector_num - sector_num % iscsilun->cluster_sectors,\n-                          BDRV_REQUEST_MAX_SECTORS, &pnum, &file);\n+        int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;\n+        int head;\n+        int64_t ret;\n+\n+        assert(cluster_sectors);\n+        head = sector_num % cluster_sectors;\n+        ret = iscsi_co_get_block_status(bs, sector_num - head,\n+                                        BDRV_REQUEST_MAX_SECTORS, &pnum,\n+                                        &file);\n         if (ret < 0) {\n             return ret;\n         }\n         /* if the whole request falls into an unallocated area we can avoid\n-         * to read and directly return zeroes instead */\n-        if (ret & BDRV_BLOCK_ZERO &&\n-            pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) {\n+         * reading and directly return zeroes instead */\n+        if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors + head) {\n             qemu_iovec_memset(iov, 0, 0x00, iov->size);\n             return 0;\n         }\n@@ -1963,8 +1977,8 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,\n      * reasonable size */\n     if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&\n         iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {\n-        iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *\n-                                     iscsilun->block_size) >> BDRV_SECTOR_BITS;\n+        iscsilun->cluster_size = iscsilun->bl.opt_unmap_gran *\n+            iscsilun->block_size;\n         if (iscsilun->lbprz) {\n             ret = iscsi_allocmap_init(iscsilun, bs->open_flags);\n         }\n@@ -2170,7 +2184,7 @@ static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)\n     IscsiLun *iscsilun = bs->opaque;\n     bdi->unallocated_blocks_are_zero = iscsilun->lbprz;\n     bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;\n-    bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;\n+    bdi->cluster_size = iscsilun->cluster_size;\n     return 0;\n }\n\n",
    "prefixes": [
        "v3",
        "05/20"
    ]
}