From nobody Wed Apr 16 07:36:58 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1499450398476494.6880088347692; Fri, 7 Jul 2017 10:59:58 -0700 (PDT) Received: from localhost ([::1]:57985 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dTXXp-0008IG-1R for importer@patchew.org; Fri, 07 Jul 2017 13:59:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43480) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dTWmX-0006dq-5a for qemu-devel@nongnu.org; Fri, 07 Jul 2017 13:11:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dTWmV-00010f-1V for qemu-devel@nongnu.org; Fri, 07 Jul 2017 13:11:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59118) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dTWmN-0000me-1M; Fri, 07 Jul 2017 13:10:55 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 13F89C0587CD; Fri, 7 Jul 2017 17:10:54 +0000 (UTC) Received: from noname.redhat.com (ovpn-117-34.ams2.redhat.com [10.36.117.34]) by smtp.corp.redhat.com (Postfix) with ESMTP id 27A8361F52; Fri, 7 Jul 2017 17:10:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 13F89C0587CD Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kwolf@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 13F89C0587CD From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 7 Jul 2017 19:08:36 +0200 Message-Id: <1499447335-6125-82-git-send-email-kwolf@redhat.com> In-Reply-To: <1499447335-6125-1-git-send-email-kwolf@redhat.com> References: <1499447335-6125-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 07 Jul 2017 17:10:54 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 081/100] qcow2: add persistent dirty bitmaps support 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, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Vladimir Sementsov-Ogievskiy Store persistent dirty bitmaps in qcow2 image. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Message-id: 20170628120530.31251-20-vsementsov@virtuozzo.com Signed-off-by: Max Reitz --- block/qcow2-bitmap.c | 475 +++++++++++++++++++++++++++++++++++++++++++++++= ++++ block/qcow2.c | 9 + block/qcow2.h | 1 + 3 files changed, 485 insertions(+) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 52e4616..5f53486 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -27,6 +27,7 @@ =20 #include "qemu/osdep.h" #include "qapi/error.h" +#include "qemu/cutils.h" =20 #include "block/block_int.h" #include "block/qcow2.h" @@ -42,6 +43,10 @@ #define BME_MIN_GRANULARITY_BITS 9 #define BME_MAX_NAME_SIZE 1023 =20 +#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 (1U << 0) @@ -72,6 +77,8 @@ typedef struct Qcow2BitmapTable { uint32_t size; /* number of 64bit entries */ QSIMPLEQ_ENTRY(Qcow2BitmapTable) entry; } Qcow2BitmapTable; +typedef QSIMPLEQ_HEAD(Qcow2BitmapTableList, Qcow2BitmapTable) + Qcow2BitmapTableList; =20 typedef struct Qcow2Bitmap { Qcow2BitmapTable table; @@ -79,6 +86,8 @@ typedef struct Qcow2Bitmap { uint8_t granularity_bits; char *name; =20 + BdrvDirtyBitmap *dirty_bitmap; + QSIMPLEQ_ENTRY(Qcow2Bitmap) entry; } Qcow2Bitmap; typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList; @@ -104,6 +113,15 @@ static int update_header_sync(BlockDriverState *bs) return bdrv_flush(bs); } =20 +static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size) +{ + size_t i; + + for (i =3D 0; i < size; ++i) { + cpu_to_be64s(&bitmap_table[i]); + } +} + static int check_table_entry(uint64_t entry, int cluster_size) { uint64_t offset; @@ -127,6 +145,70 @@ static int check_table_entry(uint64_t entry, int clust= er_size) return 0; } =20 +static int check_constraints_on_bitmap(BlockDriverState *bs, + const char *name, + uint32_t granularity, + Error **errp) +{ + BDRVQcow2State *s =3D bs->opaque; + int granularity_bits =3D ctz32(granularity); + int64_t len =3D bdrv_getlength(bs); + + assert(granularity > 0); + assert((granularity & (granularity - 1)) =3D=3D 0); + + if (len < 0) { + error_setg_errno(errp, -len, "Failed to get size of '%s'", + bdrv_get_device_or_node_name(bs)); + return len; + } + + if (granularity_bits > BME_MAX_GRANULARITY_BITS) { + error_setg(errp, "Granularity exceeds maximum (%llu bytes)", + 1ULL << BME_MAX_GRANULARITY_BITS); + return -EINVAL; + } + if (granularity_bits < BME_MIN_GRANULARITY_BITS) { + error_setg(errp, "Granularity is under minimum (%llu bytes)", + 1ULL << BME_MIN_GRANULARITY_BITS); + return -EINVAL; + } + + if ((len > (uint64_t)BME_MAX_PHYS_SIZE << granularity_bits) || + (len > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size << + granularity_bits)) + { + error_setg(errp, "Too much space will be occupied by the bitmap. " + "Use larger granularity"); + return -EINVAL; + } + + if (strlen(name) > BME_MAX_NAME_SIZE) { + error_setg(errp, "Name length exceeds maximum (%u characters)", + BME_MAX_NAME_SIZE); + return -EINVAL; + } + + return 0; +} + +static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_tabl= e, + uint32_t bitmap_table_size) +{ + BDRVQcow2State *s =3D bs->opaque; + int i; + + for (i =3D 0; i < bitmap_table_size; ++i) { + uint64_t addr =3D 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] =3D 0; + } +} + static int bitmap_table_load(BlockDriverState *bs, Qcow2BitmapTable *tb, uint64_t **bitmap_table) { @@ -165,6 +247,28 @@ fail: return ret; } =20 +static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb) +{ + int ret; + uint64_t *bitmap_table; + + ret =3D bitmap_table_load(bs, tb, &bitmap_table); + if (ret < 0) { + assert(bitmap_table =3D=3D NULL); + return ret; + } + + clear_bitmap_table(bs, bitmap_table, tb->size); + qcow2_free_clusters(bs, tb->offset, tb->size * sizeof(uint64_t), + QCOW2_DISCARD_OTHER); + g_free(bitmap_table); + + tb->offset =3D 0; + tb->size =3D 0; + + return 0; +} + /* This function returns the number of disk sectors covered by a single qc= ow2 * cluster of bitmap data. */ static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s, @@ -748,6 +852,69 @@ static int update_ext_header_and_dir_in_place(BlockDri= verState *bs, */ } =20 +static int update_ext_header_and_dir(BlockDriverState *bs, + Qcow2BitmapList *bm_list) +{ + BDRVQcow2State *s =3D bs->opaque; + int ret; + uint64_t new_offset =3D 0; + uint64_t new_size =3D 0; + uint32_t new_nb_bitmaps =3D 0; + uint64_t old_offset =3D s->bitmap_directory_offset; + uint64_t old_size =3D s->bitmap_directory_size; + uint32_t old_nb_bitmaps =3D s->nb_bitmaps; + uint64_t old_autocl =3D s->autoclear_features; + + if (bm_list !=3D NULL && !QSIMPLEQ_EMPTY(bm_list)) { + new_nb_bitmaps =3D bitmap_list_count(bm_list); + + if (new_nb_bitmaps > QCOW2_MAX_BITMAPS) { + return -EINVAL; + } + + ret =3D bitmap_list_store(bs, bm_list, &new_offset, &new_size, fal= se); + if (ret < 0) { + return ret; + } + + ret =3D bdrv_flush(bs->file->bs); + if (ret < 0) { + goto fail; + } + + s->autoclear_features |=3D QCOW2_AUTOCLEAR_BITMAPS; + } else { + s->autoclear_features &=3D ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; + } + + s->bitmap_directory_offset =3D new_offset; + s->bitmap_directory_size =3D new_size; + s->nb_bitmaps =3D new_nb_bitmaps; + + ret =3D 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 =3D old_offset; + s->bitmap_directory_size =3D old_size; + s->nb_bitmaps =3D old_nb_bitmaps; + s->autoclear_features =3D old_autocl; + + return ret; +} + /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ static void release_dirty_bitmap_helper(gpointer bitmap, gpointer bs) @@ -890,3 +1057,311 @@ out: =20 return ret; } + +/* 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 **er= rp) +{ + int ret; + BDRVQcow2State *s =3D bs->opaque; + int64_t sector; + uint64_t sbc; + uint64_t bm_size =3D bdrv_dirty_bitmap_size(bitmap); + const char *bm_name =3D bdrv_dirty_bitmap_name(bitmap); + uint8_t *buf =3D NULL; + BdrvDirtyBitmapIter *dbi; + uint64_t *tb; + uint64_t tb_size =3D + 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 =3D g_try_new0(uint64_t, tb_size); + if (tb =3D=3D NULL) { + error_setg(errp, "No memory"); + return NULL; + } + + dbi =3D bdrv_dirty_iter_new(bitmap, 0); + buf =3D g_malloc(s->cluster_size); + sbc =3D sectors_covered_by_bitmap_cluster(s, bitmap); + assert(DIV_ROUND_UP(bm_size, sbc) =3D=3D tb_size); + + while ((sector =3D bdrv_dirty_iter_next(dbi)) !=3D -1) { + uint64_t cluster =3D sector / sbc; + uint64_t end, write_size; + int64_t off; + + sector =3D cluster * sbc; + end =3D MIN(bm_size, sector + sbc); + write_size =3D + bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sec= tor); + assert(write_size <=3D s->cluster_size); + + off =3D 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] =3D 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 =3D 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 =3D bdrv_pwrite(bs->file, off, buf, s->cluster_size); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to f= ile", + bm_name); + goto fail; + } + + if (end >=3D bm_size) { + break; + } + + bdrv_set_dirty_iter(dbi, end); + } + + *bitmap_table_size =3D 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 **err= p) +{ + int ret; + uint64_t *tb; + int64_t tb_offset; + uint32_t tb_size; + BdrvDirtyBitmap *bitmap =3D bm->dirty_bitmap; + const char *bm_name; + + assert(bitmap !=3D NULL); + + bm_name =3D bdrv_dirty_bitmap_name(bitmap); + + tb =3D store_bitmap_data(bs, bitmap, &tb_size, errp); + if (tb =3D=3D NULL) { + return -EINVAL; + } + + assert(tb_size <=3D BME_MAX_TABLE_SIZE); + tb_offset =3D 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 =3D 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 =3D 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 =3D tb_offset; + bm->table.size =3D tb_size; + + return 0; + +fail: + clear_bitmap_table(bs, tb, tb_size); + + if (tb_offset > 0) { + qcow2_free_clusters(bs, tb_offset, tb_size * sizeof(tb[0]), + 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) =3D=3D 0) { + return bm; + } + } + + return NULL; +} + +void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **er= rp) +{ + BdrvDirtyBitmap *bitmap; + BDRVQcow2State *s =3D bs->opaque; + uint32_t new_nb_bitmaps =3D s->nb_bitmaps; + uint64_t new_dir_size =3D s->bitmap_directory_size; + int ret; + Qcow2BitmapList *bm_list; + Qcow2Bitmap *bm; + Qcow2BitmapTableList drop_tables; + Qcow2BitmapTable *tb, *tb_next; + + if (!bdrv_has_changed_persistent_bitmaps(bs)) { + /* nothing to do */ + return; + } + + if (!can_write(bs)) { + error_setg(errp, "No write access"); + return; + } + + QSIMPLEQ_INIT(&drop_tables); + + if (s->nb_bitmaps =3D=3D 0) { + bm_list =3D bitmap_list_new(); + } else { + bm_list =3D bitmap_list_load(bs, s->bitmap_directory_offset, + s->bitmap_directory_size, errp); + if (bm_list =3D=3D NULL) { + return; + } + } + + /* check constraints and names */ + for (bitmap =3D bdrv_dirty_bitmap_next(bs, NULL); bitmap !=3D NULL; + bitmap =3D bdrv_dirty_bitmap_next(bs, bitmap)) + { + const char *name =3D bdrv_dirty_bitmap_name(bitmap); + uint32_t granularity =3D bdrv_dirty_bitmap_granularity(bitmap); + Qcow2Bitmap *bm; + + if (!bdrv_dirty_bitmap_get_persistance(bitmap) || + bdrv_dirty_bitmap_readonly(bitmap)) + { + continue; + } + + if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) { + error_prepend(errp, "Bitmap '%s' doesn't satisfy the constrain= ts: ", + name); + goto fail; + } + + bm =3D find_bitmap_by_name(bm_list, name); + if (bm =3D=3D NULL) { + if (++new_nb_bitmaps > QCOW2_MAX_BITMAPS) { + error_setg(errp, "Too many persistent bitmaps"); + goto fail; + } + + new_dir_size +=3D calc_dir_entry_size(strlen(name), 0); + if (new_dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { + error_setg(errp, "Bitmap directory is too large"); + goto fail; + } + + bm =3D g_new0(Qcow2Bitmap, 1); + bm->name =3D g_strdup(name); + QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); + } else { + if (!(bm->flags & BME_FLAG_IN_USE)) { + error_setg(errp, "Bitmap '%s' already exists in the image", + name); + goto fail; + } + tb =3D g_memdup(&bm->table, sizeof(bm->table)); + bm->table.offset =3D 0; + bm->table.size =3D 0; + QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry); + } + bm->flags =3D bdrv_dirty_bitmap_get_autoload(bitmap) ? BME_FLAG_AU= TO : 0; + bm->granularity_bits =3D ctz32(bdrv_dirty_bitmap_granularity(bitma= p)); + bm->dirty_bitmap =3D bitmap; + } + + /* allocate clusters and store bitmaps */ + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + if (bm->dirty_bitmap =3D=3D NULL) { + continue; + } + + ret =3D store_bitmap(bs, bm, errp); + if (ret < 0) { + goto fail; + } + } + + ret =3D update_ext_header_and_dir(bs, bm_list); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to update bitmap extension"); + goto fail; + } + + /* Bitmap directory was successfully updated, so, old data can be drop= ped. + * TODO it is better to reuse these clusters */ + QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { + free_bitmap_clusters(bs, tb); + g_free(tb); + } + + bitmap_list_free(bm_list); + return; + +fail: + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + if (bm->dirty_bitmap =3D=3D NULL || bm->table.offset =3D=3D 0) { + continue; + } + + free_bitmap_clusters(bs, &bm->table); + } + + QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { + g_free(tb); + } + + bitmap_list_free(bm_list); +} diff --git a/block/qcow2.c b/block/qcow2.c index 19cc49a..790b5b1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2046,6 +2046,7 @@ static int qcow2_inactivate(BlockDriverState *bs) { BDRVQcow2State *s =3D bs->opaque; int ret, result =3D 0; + Error *local_err =3D NULL; =20 ret =3D qcow2_cache_flush(bs, s->l2_table_cache); if (ret) { @@ -2061,6 +2062,14 @@ static int qcow2_inactivate(BlockDriverState *bs) strerror(-ret)); } =20 + qcow2_store_persistent_dirty_bitmaps(bs, &local_err); + if (local_err !=3D NULL) { + result =3D -EINVAL; + error_report_err(local_err); + error_report("Persistent bitmaps are lost for node '%s'", + bdrv_get_device_or_node_name(bs)); + } + if (result =3D=3D 0) { qcow2_mark_clean(bs); } diff --git a/block/qcow2.h b/block/qcow2.h index 633bd43..308cefd 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -647,5 +647,6 @@ int qcow2_check_bitmaps_refcounts(BlockDriverState *bs,= BdrvCheckResult *res, int64_t *refcount_table_size); bool qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **er= rp); int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp); +void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **er= rp); =20 #endif --=20 1.8.3.1