From patchwork Tue Nov 22 17:26:18 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 697839 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tNY9C1DyMz9t1B for ; Wed, 23 Nov 2016 04:58:07 +1100 (AEDT) Received: from localhost ([::1]:57150 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c9FKW-00005M-Cg for incoming@patchwork.ozlabs.org; Tue, 22 Nov 2016 12:58:04 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53689) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c9EqM-0007OT-Ho for qemu-devel@nongnu.org; Tue, 22 Nov 2016 12:26:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c9EqH-0001aC-Ex for qemu-devel@nongnu.org; Tue, 22 Nov 2016 12:26:54 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:41943 helo=relay.sw.ru) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c9EqG-0001VO-U2 for qemu-devel@nongnu.org; Tue, 22 Nov 2016 12:26:49 -0500 Received: from kvm.qa.sw.ru. ([10.28.8.145]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id uAMHQVaa029558; Tue, 22 Nov 2016 20:26:43 +0300 (MSK) From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org, qemu-devel@nongnu.org Date: Tue, 22 Nov 2016 20:26:18 +0300 Message-Id: <1479835586-74394-14-git-send-email-vsementsov@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1479835586-74394-1-git-send-email-vsementsov@virtuozzo.com> References: <1479835586-74394-1-git-send-email-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x [fuzzy] X-Received-From: 195.214.232.25 Subject: [Qemu-devel] [PATCH 13/21] qcow2: add .bdrv_store_persistent_dirty_bitmaps() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, famz@redhat.com, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, den@openvz.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Realize block bitmap storing interface, to allow qcow2 images store persistent bitmaps. Signed-off-by: Vladimir Sementsov-Ogievskiy --- block/qcow2-bitmap.c | 451 +++++++++++++++++++++++++++++++++++++++++++++++++++ block/qcow2.c | 1 + block/qcow2.h | 1 + 3 files changed, 453 insertions(+) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 81be1ca..a975388 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -28,6 +28,7 @@ #include "qemu/osdep.h" #include "qapi/error.h" #include "exec/log.h" +#include "qemu/cutils.h" #include "block/block_int.h" #include "block/qcow2.h" @@ -43,6 +44,10 @@ #define BME_MIN_GRANULARITY_BITS 9 #define BME_MAX_NAME_SIZE 1023 +#if BME_MAX_TABLE_SIZE * 8ULL > INT_MAX +#error In the code bitmap table physical size assumed to fit into int +#endif + /* Bitmap directory entry flags */ #define BME_RESERVED_FLAGS 0xfffffffcU #define BME_FLAG_IN_USE 1 @@ -74,6 +79,8 @@ typedef struct Qcow2Bitmap { uint8_t granularity_bits; char *name; + BdrvDirtyBitmap *dirty_bitmap; + QSIMPLEQ_ENTRY(Qcow2Bitmap) entry; } Qcow2Bitmap; typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList; @@ -87,6 +94,27 @@ static inline bool can_write(BlockDriverState *bs) return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); } +static int update_header_sync(BlockDriverState *bs) +{ + int ret; + + ret = qcow2_update_header(bs); + if (ret < 0) { + return ret; + } + + /* We doesn't return bdrv_flush error code. Even if it fails, write was + * successful and it is more logical to consider that header is in the new + * state than in the old. + */ + ret = bdrv_flush(bs); + if (ret < 0) { + fprintf(stderr, "Failed to flush qcow2 header"); + } + + return 0; +} + static inline void bitmap_table_to_cpu(uint64_t *bitmap_table, size_t size) { size_t i; @@ -96,6 +124,15 @@ static inline void bitmap_table_to_cpu(uint64_t *bitmap_table, size_t size) } } +static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size) +{ + size_t i; + + for (i = 0; i < size; ++i) { + cpu_to_be64s(&bitmap_table[i]); + } +} + /* Check table entry specification constraints. If cluster_size is 0, offset * alignment is not checked. */ static int check_table_entry(uint64_t entry, int cluster_size) @@ -121,6 +158,51 @@ static int check_table_entry(uint64_t entry, int cluster_size) return 0; } +static int check_constraints_on_bitmap(BlockDriverState *bs, + const char *name, + uint32_t granularity) +{ + BDRVQcow2State *s = bs->opaque; + int granularity_bits = ctz32(granularity); + + int64_t nb_sectors = bdrv_nb_sectors(bs); + + if (nb_sectors < 0) { + return nb_sectors; + } + + uint64_t phys_bitmap_bytes = (nb_sectors << BDRV_SECTOR_BITS) >> + granularity_bits; + uint64_t bitmap_table_size = phys_bitmap_bytes / s->cluster_size; + size_t name_size = strlen(name); + + int fail = + (bitmap_table_size > BME_MAX_TABLE_SIZE) || + (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) || + (granularity_bits > BME_MAX_GRANULARITY_BITS) || + (granularity_bits < BME_MIN_GRANULARITY_BITS) || + (name_size > BME_MAX_NAME_SIZE); + + return fail ? -EINVAL : 0; +} + +static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table, + uint32_t bitmap_table_size) +{ + BDRVQcow2State *s = bs->opaque; + int i; + + for (i = 0; i < bitmap_table_size; ++i) { + uint64_t addr = bitmap_table[i] & BME_TABLE_ENTRY_OFFSET_MASK; + if (!addr) { + continue; + } + + qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_OTHER); + bitmap_table[i] = 0; + } +} + static int bitmap_table_load(BlockDriverState *bs, Qcow2Bitmap *bm, uint64_t **bitmap_table) { @@ -159,6 +241,28 @@ fail: return ret; } +static int free_bitmap_clusters(BlockDriverState *bs, Qcow2Bitmap *bm) +{ + int ret; + uint64_t *bitmap_table; + + ret = bitmap_table_load(bs, bm, &bitmap_table); + if (ret < 0) { + assert(bitmap_table == NULL); + return ret; + } + + clear_bitmap_table(bs, bitmap_table, bm->table_size); + qcow2_free_clusters(bs, bm->table_offset, bm->table_size * sizeof(uint64_t), + QCOW2_DISCARD_OTHER); + g_free(bitmap_table); + + bm->table_offset = 0; + bm->table_size = 0; + + return 0; +} + /* This function returns the number of disk sectors covered by a single cluster * of bitmap data. */ static uint64_t disk_sectors_in_bitmap_cluster(const BDRVQcow2State *s, @@ -603,6 +707,72 @@ fail: * Bitmap List end */ +static int update_ext_header_and_dir(BlockDriverState *bs, + Qcow2BitmapList *bm_list) +{ + BDRVQcow2State *s = bs->opaque; + int ret; + Qcow2Bitmap *bm; + uint64_t new_offset = 0; + uint64_t new_size = 0; + uint32_t new_nb_bitmaps = 0; + uint64_t old_offset = s->bitmap_directory_offset; + uint64_t old_size = s->bitmap_directory_size; + uint32_t old_nb_bitmaps = s->nb_bitmaps; + uint64_t old_autocl = s->autoclear_features; + + if (bm_list != NULL && !QSIMPLEQ_EMPTY(bm_list)) { + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + new_nb_bitmaps++; + } + + if (new_nb_bitmaps > QCOW2_MAX_BITMAPS) { + return -EINVAL; + } + + ret = bitmap_list_store(bs, bm_list, &new_offset, &new_size, false); + if (ret < 0) { + return ret; + } + + ret = bdrv_flush(bs); + if (ret < 0) { + goto fail; + } + + s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS; + } else { + s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; + } + + s->bitmap_directory_offset = new_offset; + s->bitmap_directory_size = new_size; + s->nb_bitmaps = new_nb_bitmaps; + + ret = update_header_sync(bs); + if (ret < 0) { + goto fail; + } + + if (old_size > 0) { + qcow2_free_clusters(bs, old_offset, old_size, QCOW2_DISCARD_OTHER); + } + + return 0; + +fail: + if (new_offset > 0) { + qcow2_free_clusters(bs, new_offset, new_size, QCOW2_DISCARD_OTHER); + } + + s->bitmap_directory_offset = old_offset; + s->bitmap_directory_size = old_size; + s->nb_bitmaps = old_nb_bitmaps; + s->autoclear_features = old_autocl; + + return ret; +} + /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ static void release_dirty_bitmap_helper(gpointer bitmap, gpointer bs) @@ -664,3 +834,284 @@ fail: g_slist_free(created_dirty_bitmaps); bitmap_list_free(bm_list); } + +/* store_bitmap_data() + * Store bitmap to image, filling bitmap table accordingly. + */ +static uint64_t *store_bitmap_data(BlockDriverState *bs, + BdrvDirtyBitmap *bitmap, + uint32_t *bitmap_table_size, Error **errp) +{ + int ret; + BDRVQcow2State *s = bs->opaque; + int64_t sector; + uint64_t dsc; + uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); + const char *bm_name = bdrv_dirty_bitmap_name(bitmap); + uint8_t *buf = NULL; + BdrvDirtyBitmapIter *dbi; + uint64_t *tb; + uint64_t tb_size = + size_to_clusters(s, + bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size)); + + if (tb_size > BME_MAX_TABLE_SIZE || + tb_size * s->cluster_size > BME_MAX_PHYS_SIZE) { + error_setg(errp, "Bitmap '%s' is too big", bm_name); + return NULL; + } + + tb = g_try_new0(uint64_t, tb_size); + if (tb == NULL) { + error_setg(errp, "No memory"); + return NULL; + } + + dbi = bdrv_dirty_iter_new(bitmap, 0); + buf = g_malloc(s->cluster_size); + dsc = disk_sectors_in_bitmap_cluster(s, bitmap); + + while ((sector = bdrv_dirty_iter_next(dbi)) != -1) { + uint64_t cluster = sector / dsc; + uint64_t end, write_size; + int64_t off; + + sector = cluster * dsc; + end = MIN(bm_size, sector + dsc); + write_size = + bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector); + + off = qcow2_alloc_clusters(bs, s->cluster_size); + if (off < 0) { + error_setg_errno(errp, -off, + "Failed to allocate clusters for bitmap '%s'", + bm_name); + goto fail; + } + tb[cluster] = off; + + bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end - sector); + if (write_size < s->cluster_size) { + memset(buf + write_size, 0, s->cluster_size - write_size); + } + + ret = qcow2_pre_write_overlap_check(bs, 0, off, s->cluster_size); + if (ret < 0) { + error_setg_errno(errp, -ret, "Qcow2 overlap check failed"); + goto fail; + } + + ret = bdrv_pwrite(bs->file, off, buf, s->cluster_size); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file", + bm_name); + goto fail; + } + + if (end >= bm_size) { + break; + } + + bdrv_set_dirty_iter(dbi, end); + } + + *bitmap_table_size = tb_size; + g_free(buf); + bdrv_dirty_iter_free(dbi); + + return tb; + +fail: + clear_bitmap_table(bs, tb, tb_size); + g_free(buf); + bdrv_dirty_iter_free(dbi); + g_free(tb); + + return NULL; +} + +/* store_bitmap() + * Store bm->dirty_bitmap to qcow2. + * Set bm->table_offset and bm->table_size accordingly. + */ +static int store_bitmap(BlockDriverState *bs, Qcow2Bitmap *bm, Error **errp) +{ + int ret; + uint64_t *tb; + int64_t tb_offset; + uint32_t tb_size; + BdrvDirtyBitmap *bitmap = bm->dirty_bitmap; + const char *bm_name; + + assert(bitmap != NULL); + + bm_name = bdrv_dirty_bitmap_name(bitmap); + + tb = store_bitmap_data(bs, bitmap, &tb_size, errp); + if (tb == NULL) { + g_free(tb); + return -EINVAL; + } + + assert(tb_size <= BME_MAX_TABLE_SIZE); + tb_offset = qcow2_alloc_clusters(bs, tb_size * sizeof(tb[0])); + if (tb_offset < 0) { + error_setg_errno(errp, -tb_offset, + "Failed to allocate clusters for bitmap '%s'", + bm_name); + goto fail; + } + + ret = qcow2_pre_write_overlap_check(bs, 0, tb_offset, + tb_size * sizeof(tb[0])); + if (ret < 0) { + error_setg_errno(errp, -ret, "Qcow2 overlap check failed"); + goto fail; + } + + bitmap_table_to_be(tb, tb_size); + ret = bdrv_pwrite(bs->file, tb_offset, tb, tb_size * sizeof(tb[0])); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file", + bm_name); + goto fail; + } + + g_free(tb); + + bm->table_offset = tb_offset; + bm->table_size = tb_size; + + return 0; + +fail: + clear_bitmap_table(bs, tb, tb_size); + + if (tb_offset > 0) { + qcow2_free_clusters(bs, tb_offset, tb_size, QCOW2_DISCARD_OTHER); + } + + g_free(tb); + + return ret; +} + +static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList *bm_list, + const char *name) +{ + Qcow2Bitmap *bm; + + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + if (strcmp(name, bm->name) == 0) { + return bm; + } + } + + return NULL; +} + +void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp) +{ + BdrvDirtyBitmap *bitmap; + BDRVQcow2State *s = bs->opaque; + uint32_t new_nb_bitmaps = s->nb_bitmaps; + uint64_t new_dir_size = s->bitmap_directory_size; + int ret; + Qcow2BitmapList *bm_list; + Qcow2Bitmap *bm; + + if (!bdrv_has_persistent_bitmaps(bs)) { + /* nothing to do */ + return; + } + + if (s->nb_bitmaps == 0) { + bm_list = bitmap_list_new(); + } else { + bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, + s->bitmap_directory_size, errp); + if (bm_list == NULL) { + /* errp is already set */ + return; + } + } + + /* check constraints and names */ + for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; + bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) { + const char *name = bdrv_dirty_bitmap_name(bitmap); + uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap); + Qcow2Bitmap *bm; + + if (!bdrv_dirty_bitmap_get_persistance(bitmap)) { + continue; + } + + if (++new_nb_bitmaps > QCOW2_MAX_BITMAPS) { + error_setg(errp, "Too many persistent bitmaps"); + goto fail; + } + + new_dir_size += calc_dir_entry_size(strlen(name), 0); + if (new_dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { + error_setg(errp, "Too large bitmap directory"); + goto fail; + } + + if (check_constraints_on_bitmap(bs, name, granularity) < 0) { + error_setg(errp, "Bitmap '%s' doesn't satisfy the constraints", + name); + goto fail; + } + + bm = find_bitmap_by_name(bm_list, name); + if (bm == NULL) { + bm = g_new0(Qcow2Bitmap, 1); + bm->name = g_strdup(name); + QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); + } else { + if (!(bm->flags & BME_FLAG_IN_USE) && can_write(bs)) { + error_setg(errp, "Bitmap '%s' is already exists in the image", + name); + goto fail; + } + free_bitmap_clusters(bs, bm); + /* TODO it is better to reuse these clusters */ + } + bm->flags = bdrv_dirty_bitmap_get_autoload(bitmap) ? BME_FLAG_AUTO : 0; + bm->granularity_bits = ctz32(bdrv_dirty_bitmap_granularity(bitmap)); + bm->dirty_bitmap = bitmap; + } + + /* allocate clusters and store bitmaps */ + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + if (bm->dirty_bitmap == NULL) { + continue; + } + + ret = store_bitmap(bs, bm, errp); + if (ret < 0) { + goto fail; + } + } + + ret = update_ext_header_and_dir(bs, bm_list); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to update bitmap extension"); + goto fail; + } + + bitmap_list_free(bm_list); + return; + +fail: + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + if (bm->dirty_bitmap == NULL || bm->table_offset == 0) { + continue; + } + + free_bitmap_clusters(bs, bm); + } + + bitmap_list_free(bm_list); +} diff --git a/block/qcow2.c b/block/qcow2.c index 443be0e..66c7f74 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3515,6 +3515,7 @@ BlockDriver bdrv_qcow2 = { .bdrv_attach_aio_context = qcow2_attach_aio_context, .bdrv_load_autoloading_dirty_bitmaps = qcow2_load_autoloading_dirty_bitmaps, + .bdrv_store_persistent_dirty_bitmaps = qcow2_store_persistent_dirty_bitmaps, }; static void bdrv_qcow2_init(void) diff --git a/block/qcow2.h b/block/qcow2.h index bcedf5b..d9a7643 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -615,5 +615,6 @@ void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); /* qcow2-bitmap.c functions */ void qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp); +void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp); #endif