From patchwork Fri Nov 29 16:45:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 295477 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)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A2E412C00A2 for ; Sat, 30 Nov 2013 04:06:59 +1100 (EST) Received: from localhost ([::1]:48585 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmRWr-0002oo-1M for incoming@patchwork.ozlabs.org; Fri, 29 Nov 2013 12:06:57 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54135) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmRDl-0004pY-93 for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:47:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VmRDd-0002ye-Lm for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:47:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:61893) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmRDd-0002yG-D3 for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:47:05 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rATGl4dE017686 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 29 Nov 2013 11:47:04 -0500 Received: from dhcp-200-207.str.redhat.com (ovpn-116-75.ams2.redhat.com [10.36.116.75]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rATGkEqu019151; Fri, 29 Nov 2013 11:47:02 -0500 From: Kevin Wolf To: anthony@codemonkey.ws Date: Fri, 29 Nov 2013 17:45:45 +0100 Message-Id: <1385743555-27888-31-git-send-email-kwolf@redhat.com> In-Reply-To: <1385743555-27888-1-git-send-email-kwolf@redhat.com> References: <1385743555-27888-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PULL 30/41] sheepdog: support user-defined redundancy option 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 From: Liu Yuan Sheepdog support two kinds of redundancy, full replication and erasure coding. # create a fully replicated vdi with x copies -o redundancy=x (1 <= x <= SD_MAX_COPIES) # create a erasure coded vdi with x data strips and y parity strips -o redundancy=x:y (x must be one of {2,4,8,16} and 1 <= y < SD_EC_MAX_STRIP) E.g, to convert a vdi into sheepdog vdi 'test' with 8:3 erasure coding scheme $ qemu-img convert -o redundancy=8:3 linux-0.2.img sheepdog:test Cc: Kevin Wolf Cc: Stefan Hajnoczi Signed-off-by: Liu Yuan Signed-off-by: Stefan Hajnoczi --- block/sheepdog.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++- include/block/block_int.h | 1 + 2 files changed, 74 insertions(+), 1 deletion(-) diff --git a/block/sheepdog.c b/block/sheepdog.c index ae43675..b4ae50f 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -91,6 +91,14 @@ #define SD_NR_VDIS (1U << 24) #define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22) #define SD_MAX_VDI_SIZE (SD_DATA_OBJ_SIZE * MAX_DATA_OBJS) +/* + * For erasure coding, we use at most SD_EC_MAX_STRIP for data strips and + * (SD_EC_MAX_STRIP - 1) for parity strips + * + * SD_MAX_COPIES is sum of number of data strips and parity strips. + */ +#define SD_EC_MAX_STRIP 16 +#define SD_MAX_COPIES (SD_EC_MAX_STRIP * 2 - 1) #define SD_INODE_SIZE (sizeof(SheepdogInode)) #define CURRENT_VDI_ID 0 @@ -1495,6 +1503,7 @@ static int do_sd_create(BDRVSheepdogState *s, uint32_t *vdi_id, int snapshot) hdr.data_length = wlen; hdr.vdi_size = s->inode.vdi_size; hdr.copy_policy = s->inode.copy_policy; + hdr.copies = s->inode.nr_copies; ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen); @@ -1562,6 +1571,60 @@ out: return ret; } +/* + * Sheepdog support two kinds of redundancy, full replication and erasure + * coding. + * + * # create a fully replicated vdi with x copies + * -o redundancy=x (1 <= x <= SD_MAX_COPIES) + * + * # create a erasure coded vdi with x data strips and y parity strips + * -o redundancy=x:y (x must be one of {2,4,8,16} and 1 <= y < SD_EC_MAX_STRIP) + */ +static int parse_redundancy(BDRVSheepdogState *s, const char *opt) +{ + struct SheepdogInode *inode = &s->inode; + const char *n1, *n2; + long copy, parity; + char p[10]; + + pstrcpy(p, sizeof(p), opt); + n1 = strtok(p, ":"); + n2 = strtok(NULL, ":"); + + if (!n1) { + return -EINVAL; + } + + copy = strtol(n1, NULL, 10); + if (copy > SD_MAX_COPIES || copy < 1) { + return -EINVAL; + } + if (!n2) { + inode->copy_policy = 0; + inode->nr_copies = copy; + return 0; + } + + if (copy != 2 && copy != 4 && copy != 8 && copy != 16) { + return -EINVAL; + } + + parity = strtol(n2, NULL, 10); + if (parity >= SD_EC_MAX_STRIP || parity < 1) { + return -EINVAL; + } + + /* + * 4 bits for parity and 4 bits for data. + * We have to compress upper data bits because it can't represent 16 + */ + inode->copy_policy = ((copy / 2) << 4) + parity; + inode->nr_copies = copy + parity; + + return 0; +} + static int sd_create(const char *filename, QEMUOptionParameter *options, Error **errp) { @@ -1602,6 +1665,11 @@ static int sd_create(const char *filename, QEMUOptionParameter *options, ret = -EINVAL; goto out; } + } else if (!strcmp(options->name, BLOCK_OPT_REDUNDANCY)) { + ret = parse_redundancy(s, options->value.s); + if (ret < 0) { + goto out; + } } options++; } @@ -1644,7 +1712,6 @@ static int sd_create(const char *filename, QEMUOptionParameter *options, bdrv_unref(bs); } - /* TODO: allow users to specify copy number */ ret = do_sd_create(s, &vid, 0); if (!prealloc || ret) { goto out; @@ -2432,6 +2499,11 @@ static QEMUOptionParameter sd_create_options[] = { .type = OPT_STRING, .help = "Preallocation mode (allowed values: off, full)" }, + { + .name = BLOCK_OPT_REDUNDANCY, + .type = OPT_STRING, + .help = "Redundancy of the image" + }, { NULL } }; diff --git a/include/block/block_int.h b/include/block/block_int.h index 3c5e9cb..d0f70c4 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -53,6 +53,7 @@ #define BLOCK_OPT_COMPAT_LEVEL "compat" #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" +#define BLOCK_OPT_REDUNDANCY "redundancy" typedef struct BdrvTrackedRequest { BlockDriverState *bs;