From patchwork Fri Aug 10 15:39:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Wang X-Patchwork-Id: 176515 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 93CE12C00A3 for ; Sat, 11 Aug 2012 01:41:09 +1000 (EST) Received: from localhost ([::1]:33518 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzrKl-0006jX-K7 for incoming@patchwork.ozlabs.org; Fri, 10 Aug 2012 11:41:07 -0400 Received: from eggs.gnu.org ([208.118.235.92]:58889) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzrKJ-0006Ig-4W for qemu-devel@nongnu.org; Fri, 10 Aug 2012 11:40:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SzrKF-0006a7-6I for qemu-devel@nongnu.org; Fri, 10 Aug 2012 11:40:39 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:55842) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzrKE-0006Vk-SB for qemu-devel@nongnu.org; Fri, 10 Aug 2012 11:40:35 -0400 Received: by mail-pb0-f45.google.com with SMTP id rp12so2695987pbb.4 for ; Fri, 10 Aug 2012 08:40:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=wrgAOTEHZCd6HBdiBOCbSU/Vbf89QdQVNpYkUoWRacw=; b=z4sF/uKCJgC+sFJNN9G4jSDGeRDU6Rgj5S5XH58tifTl9xFF4k9O7a82PH+iAWw07T YYxuKKQoEtnZhvm3dW14Jy4ucZ+hWc+zUCShQP8VcbFrDeqVsg7CrDI7UTWvoU7EA2HF 0IxK76rYqxwukjSnMsB9MWLME4lyJ+S1UR/6izbXnDaO2VAaLU1QvR4Y3J8IfCpeEcJl uFGnmuEWS8AG2T4zklDeojk0ZLPaJ5xsfvJxy6FSnMPGb7FRg4GyCpxGSjawNQQjA6Em MuAZBAi7UqCsuP0WsbYBLRZGJCbhJq8y8qKW8hJceLWww0F7xvaNIU+WOFPxAITKH3uP mlVw== Received: by 10.68.191.226 with SMTP id hb2mr13349170pbc.129.1344613234434; Fri, 10 Aug 2012 08:40:34 -0700 (PDT) Received: from localhost.localdomain ([202.108.130.138]) by mx.google.com with ESMTPS id os2sm3557374pbc.16.2012.08.10.08.40.30 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 10 Aug 2012 08:40:33 -0700 (PDT) From: Dong Xu Wang To: qemu-devel@nongnu.org Date: Fri, 10 Aug 2012 23:39:44 +0800 Message-Id: <1344613185-12308-6-git-send-email-wdongxu@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1344613185-12308-1-git-send-email-wdongxu@linux.vnet.ibm.com> References: <1344613185-12308-1-git-send-email-wdongxu@linux.vnet.ibm.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.160.45 Cc: kwolf@redhat.com, Dong Xu Wang Subject: [Qemu-devel] [PATCH V12 5/6] add-cow file format 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 add-cow file format core code. It use block-cache.c as cache code. Signed-off-by: Dong Xu Wang --- block/Makefile.objs | 1 + block/add-cow.c | 613 +++++++++++++++++++++++++++++++++++++++++++++++++++ block/add-cow.h | 85 +++++++ block_int.h | 2 + 4 files changed, 701 insertions(+), 0 deletions(-) create mode 100644 block/add-cow.c create mode 100644 block/add-cow.h diff --git a/block/Makefile.objs b/block/Makefile.objs index 23bdfc8..7ed5051 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -2,6 +2,7 @@ block-obj-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-obj-y += qed-check.o +block-obj-y += add-cow.o block-obj-y += block-cache.o block-obj-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o block-obj-y += stream.o diff --git a/block/add-cow.c b/block/add-cow.c new file mode 100644 index 0000000..d4711d5 --- /dev/null +++ b/block/add-cow.c @@ -0,0 +1,613 @@ +/* + * QEMU ADD-COW Disk Format + * + * Copyright IBM, Corp. 2012 + * + * Authors: + * Dong Xu Wang + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "qemu-common.h" +#include "block_int.h" +#include "module.h" +#include "add-cow.h" + +static void add_cow_header_le_to_cpu(const AddCowHeader *le, AddCowHeader *cpu) +{ + cpu->magic = le64_to_cpu(le->magic); + cpu->version = le32_to_cpu(le->version); + + cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); + cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); + + cpu->image_filename_offset = le32_to_cpu(le->image_filename_offset); + cpu->image_filename_size = le32_to_cpu(le->image_filename_size); + + cpu->features = le64_to_cpu(le->features); + cpu->optional_features = le64_to_cpu(le->optional_features); + cpu->header_pages_size = le32_to_cpu(le->header_pages_size); +} + +static void add_cow_header_cpu_to_le(const AddCowHeader *cpu, AddCowHeader *le) +{ + le->magic = cpu_to_le64(cpu->magic); + le->version = cpu_to_le32(cpu->version); + + le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); + le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); + + le->image_filename_offset = cpu_to_le32(cpu->image_filename_offset); + le->image_filename_size = cpu_to_le32(cpu->image_filename_size); + + le->features = cpu_to_le64(cpu->features); + le->optional_features = cpu_to_le64(cpu->optional_features); + le->header_pages_size = cpu_to_le32(cpu->header_pages_size); +} + +static int add_cow_probe(const uint8_t *buf, int buf_size, const char *filename) +{ + const AddCowHeader *header = (const AddCowHeader *)buf; + + if (le64_to_cpu(header->magic) == ADD_COW_MAGIC && + le32_to_cpu(header->version) == ADD_COW_VERSION) { + return 100; + } else { + return 0; + } +} + +static int add_cow_create(const char *filename, QEMUOptionParameter *options) +{ + AddCowHeader header = { + .magic = ADD_COW_MAGIC, + .version = ADD_COW_VERSION, + .features = 0, + .optional_features = 0, + .header_pages_size = ADD_COW_DEFAULT_PAGE_SIZE, + }; + AddCowHeader le_header; + int64_t image_len = 0; + const char *backing_filename = NULL; + const char *backing_fmt = NULL; + const char *image_filename = NULL; + const char *image_format = NULL; + BlockDriverState *bs, *image_bs = NULL, *backing_bs = NULL; + BlockDriver *drv = bdrv_find_format("add-cow"); + BDRVAddCowState s; + int ret; + + while (options && options->name) { + if (!strcmp(options->name, BLOCK_OPT_SIZE)) { + image_len = options->value.n; + } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { + backing_filename = options->value.s; + } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { + backing_fmt = options->value.s; + } else if (!strcmp(options->name, BLOCK_OPT_IMAGE_FILE)) { + image_filename = options->value.s; + } else if (!strcmp(options->name, BLOCK_OPT_IMAGE_FORMAT)) { + image_format = options->value.s; + } + options++; + } + + if (backing_filename) { + header.backing_filename_offset = sizeof(header) + + sizeof(s.backing_file_format) + sizeof(s.image_file_format); + header.backing_filename_size = strlen(backing_filename); + + if (!backing_fmt) { + backing_bs = bdrv_new("image"); + ret = bdrv_open(backing_bs, backing_filename, BDRV_O_RDWR + | BDRV_O_CACHE_WB, NULL); + if (ret < 0) { + return ret; + } + backing_fmt = bdrv_get_format_name(backing_bs); + bdrv_delete(backing_bs); + } + } else { + header.features |= ADD_COW_F_All_ALLOCATED; + } + + if (image_filename) { + header.image_filename_offset = + sizeof(header) + sizeof(s.backing_file_format) + + sizeof(s.image_file_format) + header.backing_filename_size; + header.image_filename_size = strlen(image_filename); + } else { + error_report("Error: image_file should be given."); + return -EINVAL; + } + + if (backing_filename && !strcmp(backing_filename, image_filename)) { + error_report("Error: Trying to create an image with the " + "same backing file name as the image file name"); + return -EINVAL; + } + + if (!strcmp(filename, image_filename)) { + error_report("Error: Trying to create an image with the " + "same filename as the image file name"); + return -EINVAL; + } + + if (header.image_filename_offset + header.image_filename_size + > ADD_COW_PAGE_SIZE * ADD_COW_DEFAULT_PAGE_SIZE) { + error_report("image_file name or backing_file name too long."); + return -ENOSPC; + } + + ret = bdrv_file_open(&image_bs, image_filename, BDRV_O_RDWR); + if (ret < 0) { + return ret; + } + bdrv_delete(image_bs); + + ret = bdrv_create_file(filename, NULL); + if (ret < 0) { + return ret; + } + + ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR); + if (ret < 0) { + return ret; + } + add_cow_header_cpu_to_le(&header, &le_header); + ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header)); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + + ret = bdrv_pwrite(bs, sizeof(le_header), backing_fmt ? backing_fmt : "", + backing_fmt ? strlen(backing_fmt) : 0); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + + ret = bdrv_pwrite(bs, sizeof(le_header) + sizeof(s.backing_file_format), + image_format ? image_format : "raw", + image_format ? strlen(image_format) : sizeof("raw")); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + + if (backing_filename) { + ret = bdrv_pwrite(bs, header.backing_filename_offset, + backing_filename, header.backing_filename_size); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + } + + ret = bdrv_pwrite(bs, header.image_filename_offset, + image_filename, header.image_filename_size); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + + ret = bdrv_open(bs, filename, BDRV_O_RDWR | BDRV_O_NO_FLUSH, drv); + if (ret < 0) { + bdrv_delete(bs); + return ret; + } + + ret = bdrv_truncate(bs, image_len); + bdrv_delete(bs); + return ret; +} + +static int add_cow_open(BlockDriverState *bs, int flags) +{ + char image_filename[ADD_COW_FILE_LEN]; + char tmp_name[ADD_COW_FILE_LEN]; + BlockDriver *image_drv = NULL; + int ret; + int sector_per_byte; + BDRVAddCowState *s = bs->opaque; + AddCowHeader le_header; + + ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); + if (ret != sizeof(s->header)) { + goto fail; + } + + add_cow_header_le_to_cpu(&le_header, &s->header); + + if (le64_to_cpu(s->header.magic) != ADD_COW_MAGIC) { + ret = -EINVAL; + goto fail; + } + + if (s->header.version != ADD_COW_VERSION) { + char version[64]; + snprintf(version, sizeof(version), "ADD-COW version %d", + s->header.version); + qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, + bs->device_name, "add-cow", version); + ret = -ENOTSUP; + goto fail; + } + + if (s->header.features & ~ADD_COW_FEATURE_MASK) { + char buf[64]; + snprintf(buf, sizeof(buf), "%" PRIx64, + s->header.features & ~ADD_COW_FEATURE_MASK); + qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, + bs->device_name, "add-cow", buf); + return -ENOTSUP; + } + + if ((s->header.features & ADD_COW_F_All_ALLOCATED) == 0) { + ret = bdrv_read_string(bs->file, sizeof(s->header), + sizeof(s->backing_file_format) - 1, s->backing_file_format, + sizeof(s->backing_file_format)); + if (ret < 0) { + goto fail; + } + } + + ret = bdrv_read_string(bs->file, + sizeof(s->header) + sizeof(s->image_file_format), + sizeof(s->image_file_format) - 1, s->image_file_format, + sizeof(s->image_file_format)); + if (ret < 0) { + goto fail; + } + + if ((s->header.features & ADD_COW_F_All_ALLOCATED) == 0) { + ret = bdrv_read_string(bs->file, s->header.backing_filename_offset, + s->header.backing_filename_size, bs->backing_file, + sizeof(bs->backing_file)); + if (ret < 0) { + goto fail; + } + } + + ret = bdrv_read_string(bs->file, s->header.image_filename_offset, + s->header.image_filename_size, tmp_name, + sizeof(tmp_name)); + if (ret < 0) { + goto fail; + } + + s->image_hd = bdrv_new(""); + if (path_has_protocol(image_filename)) { + pstrcpy(image_filename, sizeof(image_filename), tmp_name); + } else { + path_combine(image_filename, sizeof(image_filename), + bs->filename, tmp_name); + } + + ret = bdrv_open(s->image_hd, image_filename, flags, image_drv); + if (ret < 0) { + bdrv_delete(s->image_hd); + goto fail; + } + + bs->total_sectors = bdrv_getlength(s->image_hd) >> 9; + s->cluster_size = ADD_COW_CLUSTER_SIZE; + sector_per_byte = SECTORS_PER_CLUSTER * 8; + s->bitmap_size = + (bs->total_sectors + sector_per_byte - 1) / sector_per_byte; + s->bitmap_cache = + block_cache_create(bs, ADD_COW_CACHE_SIZE, ADD_COW_CACHE_ENTRY_SIZE); + + qemu_co_mutex_init(&s->lock); + return 0; +fail: + if (s->bitmap_cache) { + block_cache_destroy(bs, s->bitmap_cache, BLOCK_TABLE_BITMAP); + } + return ret; +} + +static void add_cow_close(BlockDriverState *bs) +{ + BDRVAddCowState *s = bs->opaque; + block_cache_destroy(bs, s->bitmap_cache, BLOCK_TABLE_BITMAP); + bdrv_delete(s->image_hd); +} + +static bool is_allocated(BlockDriverState *bs, int64_t sector_num) +{ + BDRVAddCowState *s = bs->opaque; + BlockCache *c = s->bitmap_cache; + int64_t cluster_num = sector_num / SECTORS_PER_CLUSTER; + uint8_t *table = NULL; + uint64_t offset = ADD_COW_PAGE_SIZE * s->header.header_pages_size + + (offset_in_bitmap(sector_num) & (~(c->entry_size - 1))); + int ret = block_cache_get(bs, s->bitmap_cache, offset, + (void **)&table, BLOCK_TABLE_BITMAP, ADD_COW_CACHE_ENTRY_SIZE); + + if (ret < 0) { + return ret; + } + return table[cluster_num / 8 % ADD_COW_CACHE_ENTRY_SIZE] + & (1 << (cluster_num % 8)); +} + +static coroutine_fn int add_cow_is_allocated(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, int *num_same) +{ + BDRVAddCowState *s = bs->opaque; + int changed; + + if (nb_sectors == 0) { + *num_same = 0; + return 0; + } + + if (s->header.features & ADD_COW_F_All_ALLOCATED) { + *num_same = nb_sectors - 1; + return 1; + } + changed = is_allocated(bs, sector_num); + + for (*num_same = 1; *num_same < nb_sectors; (*num_same)++) { + if (is_allocated(bs, sector_num + *num_same) != changed) { + break; + } + } + return changed; +} + +static int add_cow_backing_read(BlockDriverState *bs, QEMUIOVector *qiov, + int64_t sector_num, int nb_sectors) +{ + int n1; + if ((sector_num + nb_sectors) <= bs->total_sectors) { + return nb_sectors; + } + if (sector_num >= bs->total_sectors) { + n1 = 0; + } else { + n1 = bs->total_sectors - sector_num; + } + + qemu_iovec_memset(qiov, BDRV_SECTOR_SIZE * n1, + 0, BDRV_SECTOR_SIZE * (nb_sectors - n1)); + + return n1; +} + +static coroutine_fn int add_cow_co_readv(BlockDriverState *bs, + int64_t sector_num, int remaining_sectors, QEMUIOVector *qiov) +{ + BDRVAddCowState *s = bs->opaque; + int cur_nr_sectors; + uint64_t bytes_done = 0; + QEMUIOVector hd_qiov; + int n, n1, ret = 0; + + qemu_iovec_init(&hd_qiov, qiov->niov); + qemu_co_mutex_lock(&s->lock); + while (remaining_sectors != 0) { + cur_nr_sectors = remaining_sectors; + if (add_cow_is_allocated(bs, sector_num, cur_nr_sectors, &n)) { + cur_nr_sectors = n; + qemu_iovec_reset(&hd_qiov); + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, + cur_nr_sectors * BDRV_SECTOR_SIZE); + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(s->image_hd, sector_num, n, &hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + goto fail; + } + } else { + cur_nr_sectors = n; + if (bs->backing_hd) { + qemu_iovec_reset(&hd_qiov); + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, + cur_nr_sectors * BDRV_SECTOR_SIZE); + n1 = add_cow_backing_read(bs->backing_hd, &hd_qiov, + sector_num, cur_nr_sectors); + if (n1 > 0) { + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(bs->backing_hd, sector_num, + n, &hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + goto fail; + } + } + } else { + qemu_iovec_memset(&hd_qiov, 0, 0, + BDRV_SECTOR_SIZE * cur_nr_sectors); + } + } + remaining_sectors -= cur_nr_sectors; + sector_num += cur_nr_sectors; + bytes_done += cur_nr_sectors * BDRV_SECTOR_SIZE; + } +fail: + qemu_co_mutex_unlock(&s->lock); + qemu_iovec_destroy(&hd_qiov); + return ret; +} + +static int coroutine_fn copy_sectors(BlockDriverState *bs, + int n_start, int n_end) +{ + BDRVAddCowState *s = bs->opaque; + QEMUIOVector qiov; + struct iovec iov; + int n, ret; + + n = n_end - n_start; + if (n <= 0) { + return 0; + } + + iov.iov_len = n * BDRV_SECTOR_SIZE; + iov.iov_base = qemu_blockalign(bs, iov.iov_len); + + qemu_iovec_init_external(&qiov, &iov, 1); + + ret = bdrv_co_readv(bs->backing_hd, n_start, n, &qiov); + if (ret < 0) { + goto out; + } + ret = bdrv_co_writev(s->image_hd, n_start, n, &qiov); + if (ret < 0) { + goto out; + } + + ret = 0; +out: + qemu_vfree(iov.iov_base); + return ret; +} + +static coroutine_fn int add_cow_co_writev(BlockDriverState *bs, + int64_t sector_num, int remaining_sectors, QEMUIOVector *qiov) +{ + BDRVAddCowState *s = bs->opaque; + BlockCache *c = s->bitmap_cache; + int ret = 0, i; + QEMUIOVector hd_qiov; + uint8_t *table; + uint64_t offset; + + qemu_co_mutex_lock(&s->lock); + qemu_iovec_init(&hd_qiov, qiov->niov); + ret = bdrv_co_writev(s->image_hd, + sector_num, + remaining_sectors, qiov); + + if (ret < 0) { + goto fail; + } + if ((s->header.features & ADD_COW_F_All_ALLOCATED) == 0) { + /* Copy content of unmodified sectors */ + if (!is_cluster_head(sector_num) && !is_allocated(bs, sector_num)) { + ret = copy_sectors(bs, sector_num & ~(SECTORS_PER_CLUSTER - 1), + sector_num); + if (ret < 0) { + goto fail; + } + } + + if (!is_cluster_tail(sector_num + remaining_sectors - 1) + && !is_allocated(bs, sector_num + remaining_sectors - 1)) { + ret = copy_sectors(bs, sector_num + remaining_sectors, + ((sector_num + remaining_sectors) | (SECTORS_PER_CLUSTER - 1)) + 1); + if (ret < 0) { + goto fail; + } + } + + for (i = sector_num / SECTORS_PER_CLUSTER; + i <= (sector_num + remaining_sectors - 1) / SECTORS_PER_CLUSTER; + i++) { + offset = ADD_COW_PAGE_SIZE * s->header.header_pages_size + + (offset_in_bitmap(i * SECTORS_PER_CLUSTER) & (~(c->entry_size - 1))); + ret = block_cache_get(bs, s->bitmap_cache, offset, + (void **)&table, BLOCK_TABLE_BITMAP, ADD_COW_CACHE_ENTRY_SIZE); + if (ret < 0) { + goto fail; + } + if ((table[i / 8] & (1 << (i % 8))) == 0) { + table[i / 8] |= (1 << (i % 8)); + block_cache_entry_mark_dirty(s->bitmap_cache, table); + } + } + } + ret = 0; +fail: + qemu_co_mutex_unlock(&s->lock); + qemu_iovec_destroy(&hd_qiov); + return ret; +} + +static int bdrv_add_cow_truncate(BlockDriverState *bs, int64_t size) +{ + BDRVAddCowState *s = bs->opaque; + int sector_per_byte = SECTORS_PER_CLUSTER * 8; + int ret; + uint32_t bitmap_pos = s->header.header_pages_size * ADD_COW_PAGE_SIZE; + int64_t bitmap_size = + (size / BDRV_SECTOR_SIZE + sector_per_byte - 1) / sector_per_byte; + bitmap_size = (bitmap_size + ADD_COW_CACHE_ENTRY_SIZE - 1) + & (~(ADD_COW_CACHE_ENTRY_SIZE - 1)); + + ret = bdrv_truncate(bs->file, bitmap_pos + bitmap_size); + if (ret < 0) { + return ret; + } + return 0; +} + +static coroutine_fn int add_cow_co_flush(BlockDriverState *bs) +{ + BDRVAddCowState *s = bs->opaque; + int ret; + + qemu_co_mutex_lock(&s->lock); + ret = block_cache_flush(bs, s->bitmap_cache, BLOCK_TABLE_BITMAP, + ADD_COW_CACHE_ENTRY_SIZE); + qemu_co_mutex_unlock(&s->lock); + return ret; +} + +static QEMUOptionParameter add_cow_create_options[] = { + { + .name = BLOCK_OPT_SIZE, + .type = OPT_SIZE, + .help = "Virtual disk size" + }, + { + .name = BLOCK_OPT_BACKING_FILE, + .type = OPT_STRING, + .help = "File name of a base image" + }, + { + .name = BLOCK_OPT_BACKING_FMT, + .type = OPT_STRING, + .help = "Image format of the base image" + }, + { + .name = BLOCK_OPT_IMAGE_FILE, + .type = OPT_STRING, + .help = "File name of a image file" + }, + { + .name = BLOCK_OPT_IMAGE_FORMAT, + .type = OPT_STRING, + .help = "Image format of the image file" + }, + { NULL } +}; + +static BlockDriver bdrv_add_cow = { + .format_name = "add-cow", + .instance_size = sizeof(BDRVAddCowState), + .bdrv_probe = add_cow_probe, + .bdrv_open = add_cow_open, + .bdrv_close = add_cow_close, + .bdrv_create = add_cow_create, + .bdrv_co_readv = add_cow_co_readv, + .bdrv_co_writev = add_cow_co_writev, + .bdrv_truncate = bdrv_add_cow_truncate, + .bdrv_co_is_allocated = add_cow_is_allocated, + + .create_options = add_cow_create_options, + .bdrv_co_flush_to_os = add_cow_co_flush, +}; + +static void bdrv_add_cow_init(void) +{ + bdrv_register(&bdrv_add_cow); +} + +block_init(bdrv_add_cow_init); diff --git a/block/add-cow.h b/block/add-cow.h new file mode 100644 index 0000000..f058376 --- /dev/null +++ b/block/add-cow.h @@ -0,0 +1,85 @@ +/* + * QEMU ADD-COW Disk Format + * + * Copyright IBM, Corp. 2012 + * + * Authors: + * Dong Xu Wang + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#ifndef BLOCK_ADD_COW_H +#define BLOCK_ADD_COW_H +#include "block-cache.h" + +enum { + ADD_COW_F_All_ALLOCATED = 0X01, + ADD_COW_FEATURE_MASK = ADD_COW_F_All_ALLOCATED, + + ADD_COW_MAGIC = (((uint64_t)'A' << 56) | ((uint64_t)'D' << 48) | \ + ((uint64_t)'D' << 40) | ((uint64_t)'_' << 32) | \ + ((uint64_t)'C' << 24) | ((uint64_t)'O' << 16) | \ + ((uint64_t)'W' << 8) | 0xFF), + ADD_COW_VERSION = 1, + ADD_COW_FILE_LEN = 1024, + ADD_COW_CACHE_SIZE = 16, + ADD_COW_CACHE_ENTRY_SIZE = 65536, + ADD_COW_CLUSTER_SIZE = 65536, + SECTORS_PER_CLUSTER = (ADD_COW_CLUSTER_SIZE / BDRV_SECTOR_SIZE), + ADD_COW_PAGE_SIZE = 4096, + ADD_COW_DEFAULT_PAGE_SIZE = 1, +}; + +typedef struct AddCowHeader { + uint64_t magic; + uint32_t version; + + uint32_t backing_filename_offset; + uint32_t backing_filename_size; + + uint32_t image_filename_offset; + uint32_t image_filename_size; + + uint64_t features; + uint64_t optional_features; + uint32_t header_pages_size; +} QEMU_PACKED AddCowHeader; + +typedef struct BDRVAddCowState { + BlockDriverState *image_hd; + CoMutex lock; + int cluster_size; + BlockCache *bitmap_cache; + uint64_t bitmap_size; + AddCowHeader header; + char backing_file_format[16]; + char image_file_format[16]; +} BDRVAddCowState; + +/* Convert sector_num to offset in bitmap */ +static inline int64_t offset_in_bitmap(int64_t sector_num) +{ + int64_t cluster_num = sector_num / SECTORS_PER_CLUSTER; + return cluster_num / 8; +} + +static inline bool is_cluster_head(int64_t sector_num) +{ + return sector_num % SECTORS_PER_CLUSTER == 0; +} + +static inline bool is_cluster_tail(int64_t sector_num) +{ + return (sector_num + 1) % SECTORS_PER_CLUSTER == 0; +} + +BlockCache *add_cow_cache_create(BlockDriverState *bs, int num_tables); +int add_cow_cache_destroy(BlockDriverState *bs, BlockCache *c); +void add_cow_cache_entry_mark_dirty(BlockCache *c, void *table); +int add_cow_cache_get(BlockDriverState *bs, BlockCache *c, uint64_t offset, + void **table); +int add_cow_cache_flush(BlockDriverState *bs, BlockCache *c); +#endif diff --git a/block_int.h b/block_int.h index 6c1d9ca..67954ec 100644 --- a/block_int.h +++ b/block_int.h @@ -53,6 +53,8 @@ #define BLOCK_OPT_SUBFMT "subformat" #define BLOCK_OPT_COMPAT_LEVEL "compat" #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" +#define BLOCK_OPT_IMAGE_FILE "image_file" +#define BLOCK_OPT_IMAGE_FORMAT "image_format" typedef struct BdrvTrackedRequest BdrvTrackedRequest;