From patchwork Wed Apr 26 11:30:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 755446 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 3wCdTd0dpPz9s2s for ; Wed, 26 Apr 2017 21:41:57 +1000 (AEST) Received: from localhost ([::1]:54454 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3LKU-0004y2-Fa for incoming@patchwork.ozlabs.org; Wed, 26 Apr 2017 07:41:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40653) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3L9l-00041L-St for qemu-devel@nongnu.org; Wed, 26 Apr 2017 07:30:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d3L9h-0002Gn-W1 for qemu-devel@nongnu.org; Wed, 26 Apr 2017 07:30:49 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:2586 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 1d3L9h-0002Do-BF for qemu-devel@nongnu.org; Wed, 26 Apr 2017 07:30:45 -0400 Received: from kvm.sw.ru (msk-vpn.virtuozzo.com [195.214.232.6]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id v3QBUcuh028720; Wed, 26 Apr 2017 14:30:39 +0300 (MSK) From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org, qemu-devel@nongnu.org Date: Wed, 26 Apr 2017 14:30:22 +0300 Message-Id: <20170426113038.60044-9-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20170426113038.60044-1-vsementsov@virtuozzo.com> References: <20170426113038.60044-1-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 08/24] qcow2: add bitmaps extension 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" Add bitmap extension as specified in docs/specs/qcow2.txt. For now, just mirror extension header into Qcow2 state and check constraints. Also, calculate refcounts for qcow2 bitmaps, to not break qemu-img check. For now, disable image resize if it has bitmaps. It will be fixed later. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Reviewed-by: John Snow --- block/Makefile.objs | 2 +- block/qcow2-bitmap.c | 439 +++++++++++++++++++++++++++++++++++++++++++++++++ block/qcow2-refcount.c | 6 + block/qcow2.c | 124 +++++++++++++- block/qcow2.h | 27 +++ 5 files changed, 592 insertions(+), 6 deletions(-) create mode 100644 block/qcow2-bitmap.c diff --git a/block/Makefile.objs b/block/Makefile.objs index c6bd14e883..ff8d18511b 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -1,5 +1,5 @@ block-obj-y += raw-format.o qcow.o vdi.o vmdk.o cloop.o bochs.o vpc.o vvfat.o dmg.o -block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o +block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o qcow2-bitmap.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 += vhdx.o vhdx-endian.o vhdx-log.o diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c new file mode 100644 index 0000000000..b8e472b3e8 --- /dev/null +++ b/block/qcow2-bitmap.c @@ -0,0 +1,439 @@ +/* + * Bitmaps for the QCOW version 2 format + * + * Copyright (c) 2014-2017 Vladimir Sementsov-Ogievskiy + * + * This file is derived from qcow2-snapshot.c, original copyright: + * Copyright (c) 2004-2006 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" + +#include "block/block_int.h" +#include "block/qcow2.h" + +/* NOTICE: BME here means Bitmaps Extension and used as a namespace for + * _internal_ constants. Please do not use this _internal_ abbreviation for + * other needs and/or outside of this file. */ + +/* Bitmap directory entry constraints */ +#define BME_MAX_TABLE_SIZE 0x8000000 +#define BME_MAX_PHYS_SIZE 0x20000000 /* restrict BdrvDirtyBitmap size in RAM */ +#define BME_MAX_GRANULARITY_BITS 31 +#define BME_MIN_GRANULARITY_BITS 9 +#define BME_MAX_NAME_SIZE 1023 + +/* Bitmap directory entry flags */ +#define BME_RESERVED_FLAGS 0xfffffffcU + +/* bits [1, 8] U [56, 63] are reserved */ +#define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001feULL +#define BME_TABLE_ENTRY_OFFSET_MASK 0x00fffffffffffe00ULL +#define BME_TABLE_ENTRY_FLAG_ALL_ONES (1ULL << 0) + +typedef struct QEMU_PACKED Qcow2BitmapDirEntry { + /* header is 8 byte aligned */ + uint64_t bitmap_table_offset; + + uint32_t bitmap_table_size; + uint32_t flags; + + uint8_t type; + uint8_t granularity_bits; + uint16_t name_size; + uint32_t extra_data_size; + /* extra data follows */ + /* name follows */ +} Qcow2BitmapDirEntry; + +typedef struct Qcow2BitmapTable { + uint64_t offset; + uint32_t size; /* number of 64bit entries */ + QSIMPLEQ_ENTRY(Qcow2BitmapTable) entry; +} Qcow2BitmapTable; + +typedef struct Qcow2Bitmap { + Qcow2BitmapTable table; + uint32_t flags; + uint8_t granularity_bits; + char *name; + + QSIMPLEQ_ENTRY(Qcow2Bitmap) entry; +} Qcow2Bitmap; +typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList; + +typedef enum BitmapType { + BT_DIRTY_TRACKING_BITMAP = 1 +} BitmapType; + +static int check_table_entry(uint64_t entry, int cluster_size) +{ + uint64_t offset; + + if (entry & BME_TABLE_ENTRY_RESERVED_MASK) { + return -EINVAL; + } + + offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; + if (offset != 0) { + /* if offset specified, bit 0 is reserved */ + if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { + return -EINVAL; + } + + if (offset % cluster_size != 0) { + return -EINVAL; + } + } + + return 0; +} + +static int bitmap_table_load(BlockDriverState *bs, Qcow2BitmapTable *tb, + uint64_t **bitmap_table) +{ + int ret; + BDRVQcow2State *s = bs->opaque; + uint32_t i; + uint64_t *table; + + assert(tb->size != 0); + table = g_try_new(uint64_t, tb->size); + if (table == NULL) { + return -ENOMEM; + } + + assert(tb->size <= BME_MAX_TABLE_SIZE); + ret = bdrv_pread(bs->file, tb->offset, + table, tb->size * sizeof(uint64_t)); + if (ret < 0) { + goto fail; + } + + for (i = 0; i < tb->size; ++i) { + be64_to_cpus(&table[i]); + ret = check_table_entry(table[i], s->cluster_size); + if (ret < 0) { + goto fail; + } + } + + *bitmap_table = table; + return 0; + +fail: + g_free(table); + + return ret; +} + +/* + * Bitmap List + */ + +/* + * Bitmap List private functions + * Only Bitmap List knows about bitmap directory structure in Qcow2. + */ + +static inline void bitmap_dir_entry_to_cpu(Qcow2BitmapDirEntry *entry) +{ + be64_to_cpus(&entry->bitmap_table_offset); + be32_to_cpus(&entry->bitmap_table_size); + be32_to_cpus(&entry->flags); + be16_to_cpus(&entry->name_size); + be32_to_cpus(&entry->extra_data_size); +} + +static inline int calc_dir_entry_size(size_t name_size, size_t extra_data_size) +{ + return align_offset(sizeof(Qcow2BitmapDirEntry) + + name_size + extra_data_size, 8); +} + +static inline int dir_entry_size(Qcow2BitmapDirEntry *entry) +{ + return calc_dir_entry_size(entry->name_size, entry->extra_data_size); +} + +static inline const char *dir_entry_name_field(Qcow2BitmapDirEntry *entry) +{ + return (const char *)(entry + 1) + entry->extra_data_size; +} + +static inline char *dir_entry_copy_name(Qcow2BitmapDirEntry *entry) +{ + const char *name_field = dir_entry_name_field(entry); + return g_strndup(name_field, entry->name_size); +} + +static inline Qcow2BitmapDirEntry *next_dir_entry(Qcow2BitmapDirEntry *entry) +{ + return (Qcow2BitmapDirEntry *)((uint8_t *)entry + dir_entry_size(entry)); +} + +static int check_dir_entry(BlockDriverState *bs, Qcow2BitmapDirEntry *entry) +{ + BDRVQcow2State *s = bs->opaque; + uint64_t phys_bitmap_bytes; + int64_t len; + + bool fail = (entry->bitmap_table_size == 0) || + (entry->bitmap_table_offset == 0) || + (entry->bitmap_table_offset % s->cluster_size) || + (entry->bitmap_table_size > BME_MAX_TABLE_SIZE) || + (entry->granularity_bits > BME_MAX_GRANULARITY_BITS) || + (entry->granularity_bits < BME_MIN_GRANULARITY_BITS) || + (entry->flags & BME_RESERVED_FLAGS) || + (entry->name_size > BME_MAX_NAME_SIZE) || + (entry->type != BT_DIRTY_TRACKING_BITMAP); + + if (fail) { + return -EINVAL; + } + + phys_bitmap_bytes = (uint64_t)entry->bitmap_table_size * s->cluster_size; + len = bdrv_getlength(bs); + + if (len < 0) { + return len; + } + + fail = (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) || + (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)); + + return fail ? -EINVAL : 0; +} + +/* + * Bitmap List public functions + */ + +static void bitmap_free(Qcow2Bitmap *bm) +{ + g_free(bm->name); + g_free(bm); +} + +static void bitmap_list_free(Qcow2BitmapList *bm_list) +{ + Qcow2Bitmap *bm; + + if (bm_list == NULL) { + return; + } + + while ((bm = QSIMPLEQ_FIRST(bm_list)) != NULL) { + QSIMPLEQ_REMOVE_HEAD(bm_list, entry); + bitmap_free(bm); + } + + g_free(bm_list); +} + +static Qcow2BitmapList *bitmap_list_new(void) +{ + Qcow2BitmapList *bm_list = g_new(Qcow2BitmapList, 1); + QSIMPLEQ_INIT(bm_list); + + return bm_list; +} + +/* bitmap_list_load + * Get bitmap list from qcow2 image. Actually reads bitmap directory, + * checks it and convert to bitmap list. + */ +static Qcow2BitmapList *bitmap_list_load(BlockDriverState *bs, uint64_t offset, + uint64_t size, Error **errp) +{ + int ret; + BDRVQcow2State *s = bs->opaque; + uint8_t *dir, *dir_end; + Qcow2BitmapDirEntry *e; + uint32_t nb_dir_entries = 0; + Qcow2BitmapList *bm_list = NULL; + + if (size == 0) { + error_setg(errp, "Requested bitmap directory size is zero"); + return NULL; + } + + if (size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { + error_setg(errp, "Requested bitmap directory size is too big"); + return NULL; + } + + dir = g_try_malloc(size); + if (dir == NULL) { + error_setg(errp, "Failed to allocate space for bitmap directory"); + return NULL; + } + dir_end = dir + size; + + ret = bdrv_pread(bs->file, offset, dir, size); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to read bitmap directory"); + goto fail; + } + + bm_list = bitmap_list_new(); + for (e = (Qcow2BitmapDirEntry *)dir; + e < (Qcow2BitmapDirEntry *)dir_end; + e = next_dir_entry(e)) + { + Qcow2Bitmap *bm; + + if ((uint8_t *)(e + 1) > dir_end) { + goto broken_dir; + } + + if (++nb_dir_entries > s->nb_bitmaps) { + error_setg(errp, "More bitmaps found than specified in header" + " extension"); + goto fail; + } + bitmap_dir_entry_to_cpu(e); + + if ((uint8_t *)next_dir_entry(e) > dir_end) { + goto broken_dir; + } + + if (e->extra_data_size != 0) { + error_setg(errp, "Bitmap extra data is not supported"); + goto fail; + } + + ret = check_dir_entry(bs, e); + if (ret < 0) { + error_setg(errp, "Bitmap '%.*s' doesn't satisfy the constraints", + e->name_size, dir_entry_name_field(e)); + goto fail; + } + + bm = g_new(Qcow2Bitmap, 1); + bm->table.offset = e->bitmap_table_offset; + bm->table.size = e->bitmap_table_size; + bm->flags = e->flags; + bm->granularity_bits = e->granularity_bits; + bm->name = dir_entry_copy_name(e); + QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); + } + + if (nb_dir_entries != s->nb_bitmaps) { + error_setg(errp, "Less bitmaps found than specified in header" + " extension"); + goto fail; + } + + if ((uint8_t *)e != dir_end) { + goto broken_dir; + } + + g_free(dir); + return bm_list; + +broken_dir: + ret = -EINVAL; + error_setg(errp, "Broken bitmap directory"); + +fail: + g_free(dir); + bitmap_list_free(bm_list); + + return NULL; +} + +int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + void **refcount_table, + int64_t *refcount_table_size) +{ + int ret; + BDRVQcow2State *s = bs->opaque; + Qcow2BitmapList *bm_list; + Qcow2Bitmap *bm; + + if (s->nb_bitmaps == 0) { + return 0; + } + + ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size, + s->bitmap_directory_offset, + s->bitmap_directory_size); + if (ret < 0) { + return ret; + } + + bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, + s->bitmap_directory_size, NULL); + if (bm_list == NULL) { + res->corruptions++; + return -EINVAL; + } + + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + uint64_t *bitmap_table = NULL; + int i; + + ret = qcow2_inc_refcounts_imrt(bs, res, + refcount_table, refcount_table_size, + bm->table.offset, + bm->table.size * sizeof(uint64_t)); + if (ret < 0) { + goto out; + } + + ret = bitmap_table_load(bs, &bm->table, &bitmap_table); + if (ret < 0) { + res->corruptions++; + goto out; + } + + for (i = 0; i < bm->table.size; ++i) { + uint64_t entry = bitmap_table[i]; + uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; + + if (check_table_entry(entry, s->cluster_size) < 0) { + res->corruptions++; + continue; + } + + if (offset == 0) { + continue; + } + + ret = qcow2_inc_refcounts_imrt(bs, res, + refcount_table, refcount_table_size, + offset, s->cluster_size); + if (ret < 0) { + g_free(bitmap_table); + goto out; + } + } + + g_free(bitmap_table); + } + +out: + bitmap_list_free(bm_list); + + return ret; +} diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 14a736d245..cdb74ba4de 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1846,6 +1846,12 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, return ret; } + /* bitmaps */ + ret = qcow2_check_bitmaps_refcounts(bs, res, refcount_table, nb_clusters); + if (ret < 0) { + return ret; + } + return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); } diff --git a/block/qcow2.c b/block/qcow2.c index 96fb8a8f16..6cd411f9c5 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -63,6 +63,7 @@ typedef struct { #define QCOW2_EXT_MAGIC_END 0 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 +#define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) { @@ -86,12 +87,17 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) */ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, uint64_t end_offset, void **p_feature_table, - Error **errp) + bool *need_update_header, Error **errp) { BDRVQcow2State *s = bs->opaque; QCowExtension ext; uint64_t offset; int ret; + Qcow2BitmapHeaderExt bitmaps_ext; + + if (need_update_header != NULL) { + *need_update_header = false; + } #ifdef DEBUG_EXT printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); @@ -162,6 +168,85 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, } break; + case QCOW2_EXT_MAGIC_BITMAPS: + if (ext.len != sizeof(bitmaps_ext)) { + error_setg_errno(errp, -ret, "bitmaps_ext: " + "Invalid extension length"); + return -EINVAL; + } + + if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { + error_report("WARNING: a program lacking bitmap support " + "modified this file, so all bitmaps are now " + "considered inconsistent. Some clusters may be " + "leaked, run 'qemu-img check -r' on the image " + "file to fix."); + if (need_update_header != NULL) { + /* Updating is needed to drop invalid bitmap extension. */ + *need_update_header = true; + } + break; + } + + ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len); + if (ret < 0) { + error_setg_errno(errp, -ret, "bitmaps_ext: " + "Could not read ext header"); + return ret; + } + + if (bitmaps_ext.reserved32 != 0) { + error_setg_errno(errp, -ret, "bitmaps_ext: " + "Reserved field is not zero"); + return -EINVAL; + } + + be32_to_cpus(&bitmaps_ext.nb_bitmaps); + be64_to_cpus(&bitmaps_ext.bitmap_directory_size); + be64_to_cpus(&bitmaps_ext.bitmap_directory_offset); + + if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { + error_setg(errp, + "bitmaps_ext: Image has %" PRIu32 " bitmaps, " + "exceeding the QEMU supported maximum of %d", + bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); + return -EINVAL; + } + + if (bitmaps_ext.nb_bitmaps == 0) { + error_setg(errp, "found bitmaps extension with zero bitmaps"); + return -EINVAL; + } + + if (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) { + error_setg(errp, "bitmaps_ext: " + "invalid bitmap directory offset"); + return -EINVAL; + } + + if (bitmaps_ext.bitmap_directory_size > + QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { + error_setg(errp, "bitmaps_ext: " + "bitmap directory size (%" PRIu64 ") exceeds " + "the maximum supported size (%d)", + bitmaps_ext.bitmap_directory_size, + QCOW2_MAX_BITMAP_DIRECTORY_SIZE); + return -EINVAL; + } + + s->nb_bitmaps = bitmaps_ext.nb_bitmaps; + s->bitmap_directory_offset = + bitmaps_ext.bitmap_directory_offset; + s->bitmap_directory_size = + bitmaps_ext.bitmap_directory_size; + +#ifdef DEBUG_EXT + printf("Qcow2: Got bitmaps extension: " + "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", + s->bitmap_directory_offset, s->nb_bitmaps); +#endif + break; + default: /* unknown magic - save it in case we need to rewrite the header */ { @@ -824,6 +909,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, Error *local_err = NULL; uint64_t ext_end; uint64_t l1_vm_state_index; + bool need_update_header = false; ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); if (ret < 0) { @@ -929,7 +1015,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { void *feature_table = NULL; qcow2_read_extensions(bs, header.header_length, ext_end, - &feature_table, NULL); + &feature_table, NULL, NULL); report_unsupported_feature(errp, feature_table, s->incompatible_features & ~QCOW2_INCOMPAT_MASK); @@ -1116,7 +1202,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, /* read qcow2 extensions */ if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, - &local_err)) { + &need_update_header, &local_err)) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; @@ -1152,8 +1238,10 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, } /* Clear unknown autoclear feature bits */ - if (!bs->read_only && !(flags & BDRV_O_INACTIVE) && s->autoclear_features) { - s->autoclear_features = 0; + need_update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; + + if (need_update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE)) { + s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; ret = qcow2_update_header(bs); if (ret < 0) { error_setg_errno(errp, -ret, "Could not update qcow2 header"); @@ -1953,6 +2041,25 @@ int qcow2_update_header(BlockDriverState *bs) buflen -= ret; } + /* Bitmap extension */ + if (s->nb_bitmaps > 0) { + Qcow2BitmapHeaderExt bitmaps_header = { + .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), + .bitmap_directory_size = + cpu_to_be64(s->bitmap_directory_size), + .bitmap_directory_offset = + cpu_to_be64(s->bitmap_directory_offset) + }; + ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, + &bitmaps_header, sizeof(bitmaps_header), + buflen); + if (ret < 0) { + goto fail; + } + buf += ret; + buflen -= ret; + } + /* Keep unknown header extensions */ QLIST_FOREACH(uext, &s->unknown_header_ext, next) { ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); @@ -2528,6 +2635,13 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset) return -ENOTSUP; } + /* cannot proceed if image has bitmaps */ + if (s->nb_bitmaps) { + /* TODO: resize bitmaps in the image */ + error_report("Can't resize an image which has bitmaps"); + return -ENOTSUP; + } + /* shrinking is currently not supported */ if (offset < bs->total_sectors * 512) { error_report("qcow2 doesn't support shrinking images yet"); diff --git a/block/qcow2.h b/block/qcow2.h index 39c5807d09..53cd229b41 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -52,6 +52,10 @@ * space for snapshot names and IDs */ #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) +/* Bitmap header extension constraints */ +#define QCOW2_MAX_BITMAPS 65535 +#define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) + /* indicate that the refcount of the referenced cluster is exactly one. */ #define QCOW_OFLAG_COPIED (1ULL << 63) /* indicate that the cluster is compressed (they never have the copied flag) */ @@ -195,6 +199,14 @@ enum { QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, }; +/* Autoclear feature bits */ +enum { + QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0, + QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR, + + QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS, +}; + enum qcow2_discard_type { QCOW2_DISCARD_NEVER = 0, QCOW2_DISCARD_ALWAYS, @@ -222,6 +234,13 @@ typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, typedef void Qcow2SetRefcountFunc(void *refcount_array, uint64_t index, uint64_t value); +typedef struct Qcow2BitmapHeaderExt { + uint32_t nb_bitmaps; + uint32_t reserved32; + uint64_t bitmap_directory_size; + uint64_t bitmap_directory_offset; +} QEMU_PACKED Qcow2BitmapHeaderExt; + typedef struct BDRVQcow2State { int cluster_bits; int cluster_size; @@ -263,6 +282,10 @@ typedef struct BDRVQcow2State { unsigned int nb_snapshots; QCowSnapshot *snapshots; + uint32_t nb_bitmaps; + uint64_t bitmap_directory_size; + uint64_t bitmap_directory_offset; + int flags; int qcow_version; bool use_lazy_refcounts; @@ -593,4 +616,8 @@ int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, void **table); void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); +/* qcow2-bitmap.c functions */ +int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + void **refcount_table, + int64_t *refcount_table_size); #endif