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GET /api/patches/813515/?format=api
{ "id": 813515, "url": "http://patchwork.ozlabs.org/api/patches/813515/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170913160333.23622-9-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": "<20170913160333.23622-9-eblake@redhat.com>", "list_archive_url": null, "date": "2017-09-13T16:03:18", "name": "[v4,08/23] block: Switch bdrv_co_get_block_status() to byte-based", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "12bd5518942edcd69816d2d0bfea262c217d43c0", "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/20170913160333.23622-9-eblake@redhat.com/mbox/", "series": [ { "id": 2944, "url": "http://patchwork.ozlabs.org/api/series/2944/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=2944", "date": "2017-09-13T16:03:10", "name": "make bdrv_get_block_status byte-based", "version": 4, "mbox": "http://patchwork.ozlabs.org/series/2944/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/813515/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/813515/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": [ "ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=208.118.235.17; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=<UNKNOWN>)", "ext-mx07.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com", "ext-mx07.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@redhat.com" ], "Received": [ "from lists.gnu.org (lists.gnu.org [208.118.235.17])\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 3xsmtc28tXz9sPk\n\tfor <incoming@patchwork.ozlabs.org>;\n\tThu, 14 Sep 2017 02:13:44 +1000 (AEST)", "from localhost ([::1]:43397 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 1dsAII-0003fI-6U\n\tfor incoming@patchwork.ozlabs.org; Wed, 13 Sep 2017 12:13:42 -0400", "from eggs.gnu.org ([2001:4830:134:3::10]:45826)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <eblake@redhat.com>) id 1dsA9P-0001eZ-Qn\n\tfor qemu-devel@nongnu.org; Wed, 13 Sep 2017 12:04:33 -0400", "from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <eblake@redhat.com>) id 1dsA9L-0006Ax-Dj\n\tfor qemu-devel@nongnu.org; Wed, 13 Sep 2017 12:04:31 -0400", "from mx1.redhat.com ([209.132.183.28]:56734)\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 1dsA9D-00064g-8M; Wed, 13 Sep 2017 12:04:19 -0400", "from smtp.corp.redhat.com\n\t(int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11])\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 315ECC04B944;\n\tWed, 13 Sep 2017 16:04:18 +0000 (UTC)", "from red.redhat.com (ovpn-120-201.rdu2.redhat.com [10.10.120.201])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 8B18B64433;\n\tWed, 13 Sep 2017 16:04:11 +0000 (UTC)" ], "DMARC-Filter": "OpenDMARC Filter v1.3.2 mx1.redhat.com 315ECC04B944", "From": "Eric Blake <eblake@redhat.com>", "To": "qemu-devel@nongnu.org", "Date": "Wed, 13 Sep 2017 11:03:18 -0500", "Message-Id": "<20170913160333.23622-9-eblake@redhat.com>", "In-Reply-To": "<20170913160333.23622-1-eblake@redhat.com>", "References": "<20170913160333.23622-1-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 [10.5.110.31]);\n\tWed, 13 Sep 2017 16:04:18 +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 v4 08/23] block: Switch\n\tbdrv_co_get_block_status() to byte-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\tMax Reitz <mreitz@redhat.com>,\n\tStefan Hajnoczi <stefanha@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 another internal\nfunction (no semantic change); and as with its public counterpart,\nrename to bdrv_co_block_status() to make the compiler enforce that\nwe catch all uses. For now, we assert that callers still pass\naligned data, but ultimately, this will be the function where we\nhand off to a byte-based driver callback, and will eventually need\nto add logic to ensure we round calls according to the driver's\nrequest_alignment then touch up the result handed back to the\ncaller, to start permitting a caller to pass unaligned offsets.\n\nNote that we are now prepared to accepts 'bytes' larger than INT_MAX;\nthis is okay as long as we clamp things internally before violating\nany 32-bit limits, and makes no difference to how a client will\nuse the information (clients looping over the entire file must\nalready be prepared for consecutive calls to return the same status,\nas drivers are already free to return shorter-than-maximal status\ndue to any other convenient split points, such as when the L2 table\ncrosses cluster boundaries in qcow2).\n\nSigned-off-by: Eric Blake <eblake@redhat.com>\n\n---\nv4: no change\nv3: rebase to allocation/mapping sense change, clamp bytes to 32-bits\nwhen needed, drop R-b\nv2: rebase to earlier changes\n---\n block/io.c | 91 +++++++++++++++++++++++++++++++++++++-------------------------\n 1 file changed, 54 insertions(+), 37 deletions(-)", "diff": "diff --git a/block/io.c b/block/io.c\nindex 1ed46bcece..da85c903dd 100644\n--- a/block/io.c\n+++ b/block/io.c\n@@ -1748,42 +1748,43 @@ int64_t coroutine_fn bdrv_co_get_block_status_from_backing(BlockDriverState *bs,\n * possible; otherwise, the result may omit that bit particularly if\n * it allows for a larger value in 'pnum'.\n *\n- * If 'sector_num' is beyond the end of the disk image the return value is\n+ * If 'offset' is beyond the end of the disk image the return value is\n * BDRV_BLOCK_EOF and 'pnum' is set to 0.\n *\n- * 'pnum' is set to the number of sectors (including and immediately following\n- * the specified sector) that are known to be in the same\n- * allocated/unallocated state.\n+ * 'pnum' is set to the number of bytes (including and immediately following\n+ * the specified offset) that are known to be in the same\n+ * allocated/unallocated state. It may be NULL.\n *\n- * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes\n+ * 'bytes' is the max value 'pnum' should be set to. If bytes goes\n * beyond the end of the disk image it will be clamped; if 'pnum' is set to\n * the end of the image, then the returned value will include BDRV_BLOCK_EOF.\n *\n * If returned value is positive, BDRV_BLOCK_OFFSET_VALID bit is set, and\n- * 'file' is non-NULL, then '*file' points to the BDS which the sector range\n- * is allocated in.\n+ * 'file' is non-NULL, then '*file' points to the BDS which owns the\n+ * allocated sector that contains offset.\n */\n-static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,\n- bool mapping,\n- int64_t sector_num,\n- int nb_sectors, int *pnum,\n- BlockDriverState **file)\n+static int64_t coroutine_fn bdrv_co_block_status(BlockDriverState *bs,\n+ bool mapping,\n+ int64_t offset, int64_t bytes,\n+ int64_t *pnum,\n+ BlockDriverState **file)\n {\n- int64_t total_sectors;\n- int64_t n;\n+ int64_t total_size;\n+ int64_t n; /* bytes */\n int64_t ret, ret2;\n BlockDriverState *local_file = NULL;\n+ int count; /* sectors */\n\n assert(pnum);\n- total_sectors = bdrv_nb_sectors(bs);\n- if (total_sectors < 0) {\n+ total_size = bdrv_getlength(bs);\n+ if (total_size < 0) {\n if (file) {\n *file = NULL;\n }\n- return total_sectors;\n+ return total_size;\n }\n\n- if (sector_num >= total_sectors) {\n+ if (offset >= total_size) {\n *pnum = 0;\n if (file) {\n *file = NULL;\n@@ -1791,19 +1792,19 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,\n return BDRV_BLOCK_EOF;\n }\n\n- n = total_sectors - sector_num;\n- if (n < nb_sectors) {\n- nb_sectors = n;\n+ n = total_size - offset;\n+ if (n < bytes) {\n+ bytes = n;\n }\n\n if (!bs->drv->bdrv_co_get_block_status) {\n- *pnum = nb_sectors;\n+ *pnum = bytes;\n ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;\n- if (sector_num + nb_sectors == total_sectors) {\n+ if (offset + bytes == total_size) {\n ret |= BDRV_BLOCK_EOF;\n }\n if (bs->drv->protocol_name) {\n- ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);\n+ ret |= BDRV_BLOCK_OFFSET_VALID | (offset & BDRV_BLOCK_OFFSET_MASK);\n if (file) {\n *file = bs;\n }\n@@ -1814,18 +1815,28 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,\n }\n\n bdrv_inc_in_flight(bs);\n- ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum,\n+ /*\n+ * TODO: Rather than require aligned offsets, we could instead\n+ * round to the driver's request_alignment here, then touch up\n+ * count afterwards back to the caller's expectations.\n+ */\n+ assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));\n+ bytes = MIN(bytes, BDRV_REQUEST_MAX_BYTES);\n+ ret = bs->drv->bdrv_co_get_block_status(bs, offset >> BDRV_SECTOR_BITS,\n+ bytes >> BDRV_SECTOR_BITS, &count,\n &local_file);\n if (ret < 0) {\n *pnum = 0;\n goto out;\n }\n+ *pnum = count * BDRV_SECTOR_SIZE;\n\n if (ret & BDRV_BLOCK_RAW) {\n assert(ret & BDRV_BLOCK_OFFSET_VALID && local_file);\n- ret = bdrv_co_get_block_status(local_file, mapping,\n- ret >> BDRV_SECTOR_BITS,\n- *pnum, pnum, &local_file);\n+ ret = bdrv_co_block_status(local_file, mapping,\n+ ret & BDRV_BLOCK_OFFSET_MASK,\n+ *pnum, pnum, &local_file);\n+ assert(QEMU_IS_ALIGNED(*pnum, BDRV_SECTOR_SIZE));\n goto out;\n }\n\n@@ -1836,8 +1847,8 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,\n ret |= BDRV_BLOCK_ZERO;\n } else if (bs->backing) {\n BlockDriverState *bs2 = bs->backing->bs;\n- int64_t nb_sectors2 = bdrv_nb_sectors(bs2);\n- if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {\n+ int64_t size2 = bdrv_getlength(bs2);\n+ if (size2 >= 0 && offset >= size2) {\n ret |= BDRV_BLOCK_ZERO;\n }\n }\n@@ -1846,11 +1857,11 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,\n if (mapping && local_file && local_file != bs &&\n (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&\n (ret & BDRV_BLOCK_OFFSET_VALID)) {\n- int file_pnum;\n+ int64_t file_pnum;\n\n- ret2 = bdrv_co_get_block_status(local_file, mapping,\n- ret >> BDRV_SECTOR_BITS,\n- *pnum, &file_pnum, NULL);\n+ ret2 = bdrv_co_block_status(local_file, mapping,\n+ ret & BDRV_BLOCK_OFFSET_MASK,\n+ *pnum, &file_pnum, NULL);\n if (ret2 >= 0) {\n /* Ignore errors. This is just providing extra information, it\n * is useful but not necessary.\n@@ -1876,7 +1887,7 @@ out:\n *file = local_file;\n }\n bdrv_dec_in_flight(bs);\n- if (ret >= 0 && sector_num + *pnum == total_sectors) {\n+ if (ret >= 0 && offset + *pnum == total_size) {\n ret |= BDRV_BLOCK_EOF;\n }\n return ret;\n@@ -1896,11 +1907,17 @@ static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,\n\n assert(bs != base);\n for (p = bs; p != base; p = backing_bs(p)) {\n- ret = bdrv_co_get_block_status(p, mapping, sector_num, nb_sectors,\n- pnum, file);\n+ int64_t count;\n+\n+ ret = bdrv_co_block_status(p, mapping,\n+ sector_num * BDRV_SECTOR_SIZE,\n+ nb_sectors * BDRV_SECTOR_SIZE, &count,\n+ file);\n if (ret < 0) {\n break;\n }\n+ assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE));\n+ *pnum = count >> BDRV_SECTOR_BITS;\n if (ret & BDRV_BLOCK_ZERO && ret & BDRV_BLOCK_EOF && !first) {\n /*\n * Reading beyond the end of the file continues to read\n", "prefixes": [ "v4", "08/23" ] }