From patchwork Wed Sep 21 08:56:28 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Wang X-Patchwork-Id: 116038 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id ED5FBB6F83 for ; Fri, 23 Sep 2011 20:35:48 +1000 (EST) Received: from localhost ([::1]:57357 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R736d-0008Qw-US for incoming@patchwork.ozlabs.org; Fri, 23 Sep 2011 06:35:43 -0400 Received: from eggs.gnu.org ([140.186.70.92]:33017) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R736V-0008Qd-1L for qemu-devel@nongnu.org; Fri, 23 Sep 2011 06:35:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R736T-00061N-2F for qemu-devel@nongnu.org; Fri, 23 Sep 2011 06:35:34 -0400 Received: from [218.240.18.116] (port=54126 helo=wdongxu-T410) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R736S-000616-84 for qemu-devel@nongnu.org; Fri, 23 Sep 2011 06:35:32 -0400 Received: by wdongxu-T410 (Postfix, from userid 1000) id 065DB80D2B; Wed, 21 Sep 2011 16:56:54 +0800 (CST) From: Dong Xu Wang To: qemu-devel@nongnu.org Date: Wed, 21 Sep 2011 16:56:28 +0800 Message-Id: <1316595388-12427-1-git-send-email-wdongxu@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.4.1 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 218.240.18.116 Cc: kwolf@redhat.com, Dong Xu Wang , wdongxu@cn.ibm.com, stefanha@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH v2] support add-cow 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 ubuntu.img is a disk image which has been installed OS. (1) Create a raw image with the same size of ubuntu.img qemu-img create -f raw test.raw 8G (2) Create a add-cow image which will store dirty bitmap qemu-img create -f add-cow test.add-cow -o backing_file=ubuntu.img,image_file=test.raw (3) Run qemu with add-cow image qemu -drive if=virtio,file=test.add-cow -m 1024 Signed-off-by: Dong Xu Wang --- Makefile.objs | 1 + block.c | 4 +- block.h | 1 + block/add-cow.c | 403 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ block_int.h | 1 + qemu-img.c | 2 +- 6 files changed, 409 insertions(+), 3 deletions(-) create mode 100644 block/add-cow.c diff --git a/Makefile.objs b/Makefile.objs index 1c65087..2521f0d 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -31,6 +31,7 @@ block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o block-nested-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o block-nested-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o +block-nested-y += add-cow.o block-nested-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-nested-y += qed-check.o block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o diff --git a/block.c b/block.c index e3fe97f..66f2d39 100644 --- a/block.c +++ b/block.c @@ -106,7 +106,7 @@ int is_windows_drive(const char *filename) #endif /* check if the path starts with ":" */ -static int path_has_protocol(const char *path) +int path_has_protocol(const char *path) { #ifdef _WIN32 if (is_windows_drive(path) || @@ -875,7 +875,7 @@ int bdrv_commit(BlockDriverState *bs) if (!drv) return -ENOMEDIUM; - + if (!bs->backing_hd) { return -ENOTSUP; } diff --git a/block.h b/block.h index 16bfa0a..8b09f12 100644 --- a/block.h +++ b/block.h @@ -256,6 +256,7 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn); char *get_human_readable_size(char *buf, int buf_size, int64_t size); int path_is_absolute(const char *path); +int path_has_protocol(const char *path); void path_combine(char *dest, int dest_size, const char *base_path, const char *filename); diff --git a/block/add-cow.c b/block/add-cow.c new file mode 100644 index 0000000..d27be6e --- /dev/null +++ b/block/add-cow.c @@ -0,0 +1,403 @@ +#include "qemu-common.h" +#include "block_int.h" +#include "module.h" + +#define 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) +#define ADD_COW_VERSION 1 + +typedef struct AddCowHeader { + uint64_t magic; + uint32_t version; + char backing_file[1024]; + char image_file[1024]; + uint64_t size; + uint32_t sectorsize; +} QEMU_PACKED AddCowHeader; + +typedef struct BDRVAddCowState { + CoMutex lock; + CoMutex bitmap_lock; + char image_file[1024]; + BlockDriverState *image_hd; + uint8_t *bitmap; + uint64_t bitmap_size; +} BDRVAddCowState; + +static int add_cow_probe(const uint8_t *buf, int buf_size, const char *filename) +{ + const AddCowHeader *header = (const void *)buf; + + if (be64_to_cpu(header->magic) == ADD_COW_MAGIC && + be32_to_cpu(header->version) == ADD_COW_VERSION) { + return 100; + } else { + return 0; + } +} + +static int add_cow_open(BlockDriverState *bs, int flags) +{ + AddCowHeader header; + int64_t size; + char image_filename[1024]; + int image_flags; + BlockDriver *image_drv = NULL; + int ret; + BDRVAddCowState *state = (BDRVAddCowState *)(bs->opaque); + + if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header)) { + goto fail; + } + + if (be64_to_cpu(header.magic) != ADD_COW_MAGIC || + be32_to_cpu(header.version) != ADD_COW_VERSION) { + goto fail; + } + + size = be64_to_cpu(header.size); + bs->total_sectors = size / 512; + + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + header.backing_file); + pstrcpy(state->image_file, sizeof(state->image_file), + header.image_file); + + state->bitmap_size = ((bs->total_sectors + 7) >> 3); + if (!state->bitmap) { + state->bitmap = g_malloc0(state->bitmap_size); + } + if (bdrv_pread(bs->file, sizeof(header), state->bitmap, \ + state->bitmap_size) != state->bitmap_size) { + goto fail; + } + /* if there is a image_file, must be together with backing_file */ + if (state->image_file[0] != '\0') { + state->image_hd = bdrv_new(""); + if (path_has_protocol(state->image_file)) { + pstrcpy(image_filename, sizeof(image_filename), + state->image_file); + } else { + path_combine(image_filename, sizeof(image_filename), + bs->filename, state->image_file); + } + + image_drv = bdrv_find_format("raw"); + image_flags = + (flags & (~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING))) | BDRV_O_RDWR; + state->image_hd->keep_read_only = 0; + + ret = bdrv_open(state->image_hd, image_filename, image_flags, \ + image_drv); + if (ret < 0) { + bdrv_close(bs); + goto fail; + } + } + return 0; + fail: + if (state->bitmap) { + g_free(state->bitmap); + state->bitmap = NULL; + } + return -1; +} + +static inline void add_cow_set_bit(BlockDriverState *bs, int64_t bitnum) +{ + uint64_t offset = sizeof(AddCowHeader) + bitnum / 8; + uint8_t bitmap; + BDRVAddCowState *state = (BDRVAddCowState *)(bs->opaque); + + qemu_co_mutex_lock(&state->bitmap_lock); + bitmap = (state->bitmap[offset]) |= (1 << (bitnum % 8)); + qemu_co_mutex_unlock(&state->bitmap_lock); +} + +static inline int is_bit_set(BlockDriverState *bs, int64_t bitnum) +{ + BDRVAddCowState *state = (BDRVAddCowState *)(bs->opaque); + qemu_co_mutex_lock(&state->bitmap_lock); + uint64_t offset = sizeof(AddCowHeader) + bitnum / 8; + qemu_co_mutex_unlock(&state->bitmap_lock); + + return !!(state->bitmap[offset] & (1 << (bitnum % 8))); +} + +static int add_cow_is_allocated(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, int *num_same) +{ + int changed; + + if (nb_sectors == 0) { + *num_same = nb_sectors; + return 0; + } + + changed = is_bit_set(bs, sector_num); + if (changed < 0) { + return 0; + } + + for (*num_same = 1; *num_same < nb_sectors; (*num_same)++) { + if (is_bit_set(bs, sector_num + *num_same) != changed) { + break; + } + } + + return changed; +} + +static int add_cow_update_bitmap(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) +{ + int error = 0; + int i, ret; + BDRVAddCowState *state = (BDRVAddCowState *)(bs->opaque); + + for (i = 0; i < nb_sectors; i++) { + add_cow_set_bit(bs, sector_num + i); + } + ret = bdrv_pwrite_sync(bs->file, sizeof(AddCowHeader), \ + state->bitmap, state->bitmap_size); + if (ret < 0) { + return ret; + } + return error; +} + +static void add_cow_close(BlockDriverState *bs) +{ + BDRVAddCowState *state = (BDRVAddCowState *)(bs->opaque); + if (state->bitmap) { + g_free(state->bitmap); + state->bitmap = NULL; + } +} + +static int add_cow_create(const char *filename, QEMUOptionParameter *options) +{ + AddCowHeader header; + int64_t image_sectors = 0; + const char *backing_filename = NULL; + const char *image_filename = NULL; + int ret; + BlockDriverState *bs, *image_bs = NULL; + + while (options && options->name) { + if (!strcmp(options->name, BLOCK_OPT_SIZE)) { + image_sectors = options->value.n / 512; + } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { + backing_filename = options->value.s; + } else if (!strcmp(options->name, BLOCK_OPT_IMAGE_FILE)) { + image_filename = options->value.s; + } + options++; + } + + if (!backing_filename || !image_filename) { + return -EINVAL; + } + /* Make sure image file exists */ + BlockDriver *raw_drv = bdrv_find_format("raw"); + assert(raw_drv != NULL); + ret = bdrv_file_open(&image_bs, image_filename, BDRV_O_RDWR | \ + BDRV_O_CACHE_WB); + if (ret < 0) { + return ret; + } + bdrv_close(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; + } + + memset(&header, 0, sizeof(header)); + header.magic = cpu_to_be64(ADD_COW_MAGIC); + header.version = cpu_to_be32(ADD_COW_VERSION); + pstrcpy(header.backing_file, \ + sizeof(header.backing_file), backing_filename); + pstrcpy(header.image_file, sizeof(header.image_file), + image_filename); + + header.sectorsize = cpu_to_be32(512); + header.size = cpu_to_be64(image_sectors * 512); + + ret = bdrv_pwrite(bs, 0, &header, sizeof(header)); + if (ret < 0) { + return ret; + } + bdrv_close(bs); + + BlockDriver *drv = bdrv_find_format("add-cow"); + assert(drv != NULL); + ret = bdrv_open(bs, filename, BDRV_O_RDWR | BDRV_O_NO_FLUSH, drv); + if (ret < 0) { + return ret; + } + + ret = bdrv_truncate(bs, ((image_sectors + 7) >> 3)); + if (ret < 0) { + return ret; + } + return ret; +} + + +static 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, 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_copy(&hd_qiov, qiov, bytes_done, + cur_nr_sectors * 512); + 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_copy(&hd_qiov, qiov, bytes_done, + cur_nr_sectors * 512); + 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, 512 * cur_nr_sectors); + } + } + remaining_sectors -= cur_nr_sectors; + sector_num += cur_nr_sectors; + bytes_done += cur_nr_sectors * 512; + } +fail: + qemu_co_mutex_unlock(&s->lock); + qemu_iovec_destroy(&hd_qiov); + return ret; +} + +static int add_cow_co_writev(BlockDriverState *bs, int64_t sector_num, + int remaining_sectors, QEMUIOVector *qiov) +{ + BDRVAddCowState *s = bs->opaque; + int ret; + int cur_nr_sectors = remaining_sectors; + QEMUIOVector hd_qiov; + uint64_t bytes_done = 0; + qemu_iovec_init(&hd_qiov, qiov->niov); + qemu_co_mutex_lock(&s->lock); + + qemu_iovec_reset(&hd_qiov); + qemu_iovec_copy(&hd_qiov, qiov, bytes_done, cur_nr_sectors * 512); + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_writev(s->image_hd, + sector_num, + cur_nr_sectors, &hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + goto fail; + } + + qemu_co_mutex_unlock(&s->lock); + add_cow_update_bitmap(bs, sector_num, remaining_sectors); + ret = 0; +fail: + qemu_iovec_destroy(&hd_qiov); + return ret; +} + +static int bdrv_add_cow_truncate(BlockDriverState *bs, int64_t offset) +{ + int ret; + ret = bdrv_truncate(bs->file, offset + sizeof(AddCowHeader)); + if (ret < 0) { + return ret; + } + + return 0; +} + +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_IMAGE_FILE, + .type = OPT_STRING, + .help = "File name of a image file" + }, + { NULL } +}; + +static int add_cow_flush(BlockDriverState *bs) +{ + BDRVAddCowState *state = bs->opaque; + return bdrv_flush(bs->file) | bdrv_flush(state->image_hd); +} + +static BlockDriverAIOCB *add_cow_aio_flush(BlockDriverState *bs, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BDRVAddCowState *state = bs->opaque; + bdrv_aio_flush(state->image_hd, cb, opaque); + return bdrv_aio_flush(bs->file, cb, opaque); + +} + +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_is_allocated = add_cow_is_allocated, + + .bdrv_co_readv = add_cow_co_readv, + .bdrv_co_writev = add_cow_co_writev, + .bdrv_truncate = bdrv_add_cow_truncate, + + .create_options = add_cow_create_options, + .bdrv_flush = add_cow_flush, + .bdrv_aio_flush = add_cow_aio_flush, +}; + +static void bdrv_add_cow_init(void) +{ + bdrv_register(&bdrv_add_cow); +} + +block_init(bdrv_add_cow_init); diff --git a/block_int.h b/block_int.h index 8c3b863..2b26fdc 100644 --- a/block_int.h +++ b/block_int.h @@ -42,6 +42,7 @@ #define BLOCK_OPT_TABLE_SIZE "table_size" #define BLOCK_OPT_PREALLOC "preallocation" #define BLOCK_OPT_SUBFMT "subformat" +#define BLOCK_OPT_IMAGE_FILE "image_file" typedef struct AIOPool { void (*cancel)(BlockDriverAIOCB *acb); diff --git a/qemu-img.c b/qemu-img.c index 6a39731..6335234 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -746,7 +746,7 @@ static int img_convert(int argc, char **argv) ret = -1; goto out; } - + qemu_progress_init(progress, 2.0); qemu_progress_print(0, 100);