1809 lines
52 KiB
C
1809 lines
52 KiB
C
/*
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* Bitmaps for the QCOW version 2 format
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*
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* Copyright (c) 2014-2017 Vladimir Sementsov-Ogievskiy
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*
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* This file is derived from qcow2-snapshot.c, original copyright:
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "qapi/error.h"
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#include "qemu/cutils.h"
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#include "qcow2.h"
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/* NOTICE: BME here means Bitmaps Extension and used as a namespace for
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* _internal_ constants. Please do not use this _internal_ abbreviation for
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* other needs and/or outside of this file. */
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/* Bitmap directory entry constraints */
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#define BME_MAX_TABLE_SIZE 0x8000000
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#define BME_MAX_PHYS_SIZE 0x20000000 /* restrict BdrvDirtyBitmap size in RAM */
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#define BME_MAX_GRANULARITY_BITS 31
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#define BME_MIN_GRANULARITY_BITS 9
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#define BME_MAX_NAME_SIZE 1023
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QEMU_BUILD_BUG_ON(BME_MAX_NAME_SIZE != BDRV_BITMAP_MAX_NAME_SIZE);
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#if BME_MAX_TABLE_SIZE * 8ULL > INT_MAX
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#error In the code bitmap table physical size assumed to fit into int
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#endif
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/* Bitmap directory entry flags */
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#define BME_RESERVED_FLAGS 0xfffffffcU
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#define BME_FLAG_IN_USE (1U << 0)
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#define BME_FLAG_AUTO (1U << 1)
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/* bits [1, 8] U [56, 63] are reserved */
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#define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001feULL
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#define BME_TABLE_ENTRY_OFFSET_MASK 0x00fffffffffffe00ULL
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#define BME_TABLE_ENTRY_FLAG_ALL_ONES (1ULL << 0)
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typedef struct QEMU_PACKED Qcow2BitmapDirEntry {
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/* header is 8 byte aligned */
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uint64_t bitmap_table_offset;
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uint32_t bitmap_table_size;
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uint32_t flags;
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uint8_t type;
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uint8_t granularity_bits;
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uint16_t name_size;
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uint32_t extra_data_size;
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/* extra data follows */
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/* name follows */
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} Qcow2BitmapDirEntry;
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typedef struct Qcow2BitmapTable {
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uint64_t offset;
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uint32_t size; /* number of 64bit entries */
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QSIMPLEQ_ENTRY(Qcow2BitmapTable) entry;
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} Qcow2BitmapTable;
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typedef struct Qcow2Bitmap {
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Qcow2BitmapTable table;
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uint32_t flags;
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uint8_t granularity_bits;
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char *name;
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BdrvDirtyBitmap *dirty_bitmap;
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QSIMPLEQ_ENTRY(Qcow2Bitmap) entry;
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} Qcow2Bitmap;
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typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList;
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typedef enum BitmapType {
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BT_DIRTY_TRACKING_BITMAP = 1
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} BitmapType;
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static inline bool can_write(BlockDriverState *bs)
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{
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return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
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}
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static int update_header_sync(BlockDriverState *bs)
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{
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int ret;
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ret = qcow2_update_header(bs);
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if (ret < 0) {
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return ret;
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}
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return bdrv_flush(bs->file->bs);
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}
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static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size)
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{
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size_t i;
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for (i = 0; i < size; ++i) {
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bitmap_table[i] = cpu_to_be64(bitmap_table[i]);
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}
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}
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static int check_table_entry(uint64_t entry, int cluster_size)
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{
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uint64_t offset;
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if (entry & BME_TABLE_ENTRY_RESERVED_MASK) {
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return -EINVAL;
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}
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offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
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if (offset != 0) {
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/* if offset specified, bit 0 is reserved */
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if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
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return -EINVAL;
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}
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if (offset % cluster_size != 0) {
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return -EINVAL;
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}
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}
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return 0;
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}
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static int64_t get_bitmap_bytes_needed(int64_t len, uint32_t granularity)
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{
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int64_t num_bits = DIV_ROUND_UP(len, granularity);
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return DIV_ROUND_UP(num_bits, 8);
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}
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static int check_constraints_on_bitmap(BlockDriverState *bs,
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const char *name,
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uint32_t granularity,
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Error **errp)
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{
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BDRVQcow2State *s = bs->opaque;
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int granularity_bits = ctz32(granularity);
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int64_t len = bdrv_getlength(bs);
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int64_t bitmap_bytes;
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assert(granularity > 0);
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assert((granularity & (granularity - 1)) == 0);
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if (len < 0) {
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error_setg_errno(errp, -len, "Failed to get size of '%s'",
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bdrv_get_device_or_node_name(bs));
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return len;
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}
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if (granularity_bits > BME_MAX_GRANULARITY_BITS) {
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error_setg(errp, "Granularity exceeds maximum (%llu bytes)",
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1ULL << BME_MAX_GRANULARITY_BITS);
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return -EINVAL;
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}
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if (granularity_bits < BME_MIN_GRANULARITY_BITS) {
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error_setg(errp, "Granularity is under minimum (%llu bytes)",
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1ULL << BME_MIN_GRANULARITY_BITS);
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return -EINVAL;
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}
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bitmap_bytes = get_bitmap_bytes_needed(len, granularity);
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if ((bitmap_bytes > (uint64_t)BME_MAX_PHYS_SIZE) ||
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(bitmap_bytes > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size))
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{
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error_setg(errp, "Too much space will be occupied by the bitmap. "
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"Use larger granularity");
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return -EINVAL;
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}
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if (strlen(name) > BME_MAX_NAME_SIZE) {
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error_setg(errp, "Name length exceeds maximum (%u characters)",
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BME_MAX_NAME_SIZE);
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return -EINVAL;
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}
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return 0;
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}
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static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table,
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uint32_t bitmap_table_size)
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{
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BDRVQcow2State *s = bs->opaque;
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int i;
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for (i = 0; i < bitmap_table_size; ++i) {
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uint64_t addr = bitmap_table[i] & BME_TABLE_ENTRY_OFFSET_MASK;
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if (!addr) {
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continue;
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}
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qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_ALWAYS);
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bitmap_table[i] = 0;
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}
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}
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static int bitmap_table_load(BlockDriverState *bs, Qcow2BitmapTable *tb,
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uint64_t **bitmap_table)
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{
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int ret;
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BDRVQcow2State *s = bs->opaque;
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uint32_t i;
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uint64_t *table;
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assert(tb->size != 0);
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table = g_try_new(uint64_t, tb->size);
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if (table == NULL) {
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return -ENOMEM;
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}
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assert(tb->size <= BME_MAX_TABLE_SIZE);
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ret = bdrv_pread(bs->file, tb->offset,
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table, tb->size * sizeof(uint64_t));
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if (ret < 0) {
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goto fail;
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}
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for (i = 0; i < tb->size; ++i) {
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table[i] = be64_to_cpu(table[i]);
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ret = check_table_entry(table[i], s->cluster_size);
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if (ret < 0) {
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goto fail;
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}
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}
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*bitmap_table = table;
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return 0;
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fail:
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g_free(table);
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return ret;
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}
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static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb)
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{
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int ret;
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uint64_t *bitmap_table;
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ret = bitmap_table_load(bs, tb, &bitmap_table);
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if (ret < 0) {
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return ret;
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}
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clear_bitmap_table(bs, bitmap_table, tb->size);
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qcow2_free_clusters(bs, tb->offset, tb->size * sizeof(uint64_t),
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QCOW2_DISCARD_OTHER);
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g_free(bitmap_table);
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tb->offset = 0;
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tb->size = 0;
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return 0;
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}
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/* Return the disk size covered by a single qcow2 cluster of bitmap data. */
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static uint64_t bytes_covered_by_bitmap_cluster(const BDRVQcow2State *s,
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const BdrvDirtyBitmap *bitmap)
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{
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uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
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uint64_t limit = granularity * (s->cluster_size << 3);
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assert(QEMU_IS_ALIGNED(limit,
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bdrv_dirty_bitmap_serialization_align(bitmap)));
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return limit;
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}
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/* load_bitmap_data
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* @bitmap_table entries must satisfy specification constraints.
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* @bitmap must be cleared */
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static int load_bitmap_data(BlockDriverState *bs,
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const uint64_t *bitmap_table,
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uint32_t bitmap_table_size,
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BdrvDirtyBitmap *bitmap)
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{
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int ret = 0;
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BDRVQcow2State *s = bs->opaque;
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uint64_t offset, limit;
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uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
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uint8_t *buf = NULL;
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uint64_t i, tab_size =
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size_to_clusters(s,
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bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
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if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) {
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return -EINVAL;
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}
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buf = g_malloc(s->cluster_size);
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limit = bytes_covered_by_bitmap_cluster(s, bitmap);
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for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) {
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uint64_t count = MIN(bm_size - offset, limit);
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uint64_t entry = bitmap_table[i];
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uint64_t data_offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
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assert(check_table_entry(entry, s->cluster_size) == 0);
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if (data_offset == 0) {
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if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
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bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count,
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false);
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} else {
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/* No need to deserialize zeros because the dirty bitmap is
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* already cleared */
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}
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} else {
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ret = bdrv_pread(bs->file, data_offset, buf, s->cluster_size);
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if (ret < 0) {
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goto finish;
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}
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bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count,
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false);
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}
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}
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ret = 0;
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bdrv_dirty_bitmap_deserialize_finish(bitmap);
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finish:
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g_free(buf);
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return ret;
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}
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static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs,
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Qcow2Bitmap *bm, Error **errp)
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{
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int ret;
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uint64_t *bitmap_table = NULL;
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uint32_t granularity;
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BdrvDirtyBitmap *bitmap = NULL;
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granularity = 1U << bm->granularity_bits;
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bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp);
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if (bitmap == NULL) {
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goto fail;
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}
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if (bm->flags & BME_FLAG_IN_USE) {
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/* Data is unusable, skip loading it */
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return bitmap;
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}
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ret = bitmap_table_load(bs, &bm->table, &bitmap_table);
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if (ret < 0) {
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error_setg_errno(errp, -ret,
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"Could not read bitmap_table table from image for "
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"bitmap '%s'", bm->name);
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goto fail;
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}
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ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap);
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if (ret < 0) {
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error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image",
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bm->name);
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goto fail;
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}
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g_free(bitmap_table);
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return bitmap;
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fail:
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g_free(bitmap_table);
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if (bitmap != NULL) {
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bdrv_release_dirty_bitmap(bitmap);
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}
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return NULL;
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}
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/*
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* Bitmap List
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*/
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/*
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* Bitmap List private functions
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* Only Bitmap List knows about bitmap directory structure in Qcow2.
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*/
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static inline void bitmap_dir_entry_to_cpu(Qcow2BitmapDirEntry *entry)
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{
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entry->bitmap_table_offset = be64_to_cpu(entry->bitmap_table_offset);
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entry->bitmap_table_size = be32_to_cpu(entry->bitmap_table_size);
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entry->flags = be32_to_cpu(entry->flags);
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entry->name_size = be16_to_cpu(entry->name_size);
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entry->extra_data_size = be32_to_cpu(entry->extra_data_size);
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}
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static inline void bitmap_dir_entry_to_be(Qcow2BitmapDirEntry *entry)
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{
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entry->bitmap_table_offset = cpu_to_be64(entry->bitmap_table_offset);
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entry->bitmap_table_size = cpu_to_be32(entry->bitmap_table_size);
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entry->flags = cpu_to_be32(entry->flags);
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entry->name_size = cpu_to_be16(entry->name_size);
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entry->extra_data_size = cpu_to_be32(entry->extra_data_size);
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}
|
|
|
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static inline int calc_dir_entry_size(size_t name_size, size_t extra_data_size)
|
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{
|
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int size = sizeof(Qcow2BitmapDirEntry) + name_size + extra_data_size;
|
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return ROUND_UP(size, 8);
|
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}
|
|
|
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static inline int dir_entry_size(Qcow2BitmapDirEntry *entry)
|
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{
|
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return calc_dir_entry_size(entry->name_size, entry->extra_data_size);
|
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}
|
|
|
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static inline const char *dir_entry_name_field(Qcow2BitmapDirEntry *entry)
|
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{
|
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return (const char *)(entry + 1) + entry->extra_data_size;
|
|
}
|
|
|
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static inline char *dir_entry_copy_name(Qcow2BitmapDirEntry *entry)
|
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{
|
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const char *name_field = dir_entry_name_field(entry);
|
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return g_strndup(name_field, entry->name_size);
|
|
}
|
|
|
|
static inline Qcow2BitmapDirEntry *next_dir_entry(Qcow2BitmapDirEntry *entry)
|
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{
|
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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;
|
|
}
|
|
|
|
if (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!(entry->flags & BME_FLAG_IN_USE) &&
|
|
(len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)))
|
|
{
|
|
/*
|
|
* We've loaded a valid bitmap (IN_USE not set) or we are going to
|
|
* store a valid bitmap, but the allocated bitmap table size is not
|
|
* enough to store this bitmap.
|
|
*
|
|
* Note, that it's OK to have an invalid bitmap with invalid size due
|
|
* to a bitmap that was not correctly saved after image resize.
|
|
*/
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void bitmap_directory_to_be(uint8_t *dir, size_t size)
|
|
{
|
|
uint8_t *end = dir + size;
|
|
while (dir < end) {
|
|
Qcow2BitmapDirEntry *e = (Qcow2BitmapDirEntry *)dir;
|
|
dir += dir_entry_size(e);
|
|
|
|
bitmap_dir_entry_to_be(e);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Bitmap List public functions
|
|
*/
|
|
|
|
static void bitmap_free(Qcow2Bitmap *bm)
|
|
{
|
|
if (bm == NULL) {
|
|
return;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static uint32_t bitmap_list_count(Qcow2BitmapList *bm_list)
|
|
{
|
|
Qcow2Bitmap *bm;
|
|
uint32_t nb_bitmaps = 0;
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
nb_bitmaps++;
|
|
}
|
|
|
|
return nb_bitmaps;
|
|
}
|
|
|
|
/* 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_new0(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:
|
|
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;
|
|
}
|
|
|
|
/* bitmap_list_store
|
|
* Store bitmap list to qcow2 image as a bitmap directory.
|
|
* Everything is checked.
|
|
*/
|
|
static int bitmap_list_store(BlockDriverState *bs, Qcow2BitmapList *bm_list,
|
|
uint64_t *offset, uint64_t *size, bool in_place)
|
|
{
|
|
int ret;
|
|
uint8_t *dir;
|
|
int64_t dir_offset = 0;
|
|
uint64_t dir_size = 0;
|
|
Qcow2Bitmap *bm;
|
|
Qcow2BitmapDirEntry *e;
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
dir_size += calc_dir_entry_size(strlen(bm->name), 0);
|
|
}
|
|
|
|
if (dir_size == 0 || dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (in_place) {
|
|
if (*size != dir_size || *offset == 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
dir_offset = *offset;
|
|
}
|
|
|
|
dir = g_try_malloc0(dir_size);
|
|
if (dir == NULL) {
|
|
return -ENOMEM;
|
|
}
|
|
|
|
e = (Qcow2BitmapDirEntry *)dir;
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
e->bitmap_table_offset = bm->table.offset;
|
|
e->bitmap_table_size = bm->table.size;
|
|
e->flags = bm->flags;
|
|
e->type = BT_DIRTY_TRACKING_BITMAP;
|
|
e->granularity_bits = bm->granularity_bits;
|
|
e->name_size = strlen(bm->name);
|
|
e->extra_data_size = 0;
|
|
memcpy(e + 1, bm->name, e->name_size);
|
|
|
|
if (check_dir_entry(bs, e) < 0) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
e = next_dir_entry(e);
|
|
}
|
|
|
|
bitmap_directory_to_be(dir, dir_size);
|
|
|
|
if (!in_place) {
|
|
dir_offset = qcow2_alloc_clusters(bs, dir_size);
|
|
if (dir_offset < 0) {
|
|
ret = dir_offset;
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
/* Actually, even in in-place case ignoring QCOW2_OL_BITMAP_DIRECTORY is not
|
|
* necessary, because we drop QCOW2_AUTOCLEAR_BITMAPS when updating bitmap
|
|
* directory in-place (actually, turn-off the extension), which is checked
|
|
* in qcow2_check_metadata_overlap() */
|
|
ret = qcow2_pre_write_overlap_check(
|
|
bs, in_place ? QCOW2_OL_BITMAP_DIRECTORY : 0, dir_offset, dir_size,
|
|
false);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
ret = bdrv_pwrite(bs->file, dir_offset, dir, dir_size);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
g_free(dir);
|
|
|
|
if (!in_place) {
|
|
*size = dir_size;
|
|
*offset = dir_offset;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
g_free(dir);
|
|
|
|
if (!in_place && dir_offset > 0) {
|
|
qcow2_free_clusters(bs, dir_offset, dir_size, QCOW2_DISCARD_OTHER);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Bitmap List end
|
|
*/
|
|
|
|
static int update_ext_header_and_dir_in_place(BlockDriverState *bs,
|
|
Qcow2BitmapList *bm_list)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
int ret;
|
|
|
|
if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS) ||
|
|
bm_list == NULL || QSIMPLEQ_EMPTY(bm_list) ||
|
|
bitmap_list_count(bm_list) != s->nb_bitmaps)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS;
|
|
ret = update_header_sync(bs);
|
|
if (ret < 0) {
|
|
/* Two variants are possible here:
|
|
* 1. Autoclear flag is dropped, all bitmaps will be lost.
|
|
* 2. Autoclear flag is not dropped, old state is left.
|
|
*/
|
|
return ret;
|
|
}
|
|
|
|
/* autoclear bit is not set, so we can safely update bitmap directory */
|
|
|
|
ret = bitmap_list_store(bs, bm_list, &s->bitmap_directory_offset,
|
|
&s->bitmap_directory_size, true);
|
|
if (ret < 0) {
|
|
/* autoclear bit is cleared, so all leaked clusters would be removed on
|
|
* qemu-img check */
|
|
return ret;
|
|
}
|
|
|
|
ret = update_header_sync(bs);
|
|
if (ret < 0) {
|
|
/* autoclear bit is cleared, so all leaked clusters would be removed on
|
|
* qemu-img check */
|
|
return ret;
|
|
}
|
|
|
|
s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS;
|
|
return update_header_sync(bs);
|
|
/* If final update_header_sync() fails, two variants are possible:
|
|
* 1. Autoclear flag is not set, all bitmaps will be lost.
|
|
* 2. Autoclear flag is set, header and directory are successfully updated.
|
|
*/
|
|
}
|
|
|
|
static int update_ext_header_and_dir(BlockDriverState *bs,
|
|
Qcow2BitmapList *bm_list)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
int ret;
|
|
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)) {
|
|
new_nb_bitmaps = bitmap_list_count(bm_list);
|
|
|
|
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 = qcow2_flush_caches(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)
|
|
{
|
|
bdrv_release_dirty_bitmap(bitmap);
|
|
}
|
|
|
|
/* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */
|
|
static void set_readonly_helper(gpointer bitmap, gpointer value)
|
|
{
|
|
bdrv_dirty_bitmap_set_readonly(bitmap, (bool)value);
|
|
}
|
|
|
|
/* qcow2_load_dirty_bitmaps()
|
|
* Return value is a hint for caller: true means that the Qcow2 header was
|
|
* updated. (false doesn't mean that the header should be updated by the
|
|
* caller, it just means that updating was not needed or the image cannot be
|
|
* written to).
|
|
* On failure the function returns false.
|
|
*/
|
|
bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
Qcow2BitmapList *bm_list;
|
|
Qcow2Bitmap *bm;
|
|
GSList *created_dirty_bitmaps = NULL;
|
|
bool header_updated = false;
|
|
bool needs_update = false;
|
|
|
|
if (s->nb_bitmaps == 0) {
|
|
/* No bitmaps - nothing to do */
|
|
return false;
|
|
}
|
|
|
|
bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
|
|
s->bitmap_directory_size, errp);
|
|
if (bm_list == NULL) {
|
|
return false;
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
BdrvDirtyBitmap *bitmap;
|
|
|
|
if ((bm->flags & BME_FLAG_IN_USE) &&
|
|
bdrv_find_dirty_bitmap(bs, bm->name))
|
|
{
|
|
/*
|
|
* We already have corresponding BdrvDirtyBitmap, and bitmap in the
|
|
* image is marked IN_USE. Firstly, this state is valid, no reason
|
|
* to consider existing BdrvDirtyBitmap to be bad. Secondly it's
|
|
* absolutely possible, when we do migration with shared storage
|
|
* with dirty-bitmaps capability enabled: if the bitmap was loaded
|
|
* from this storage before migration start, the storage will
|
|
* of-course contain IN_USE outdated version of the bitmap, and we
|
|
* should not load it on migration target, as we already have this
|
|
* bitmap, being migrated.
|
|
*/
|
|
continue;
|
|
}
|
|
|
|
bitmap = load_bitmap(bs, bm, errp);
|
|
if (bitmap == NULL) {
|
|
goto fail;
|
|
}
|
|
|
|
bdrv_dirty_bitmap_set_persistence(bitmap, true);
|
|
if (bm->flags & BME_FLAG_IN_USE) {
|
|
bdrv_dirty_bitmap_set_inconsistent(bitmap);
|
|
} else {
|
|
/* NB: updated flags only get written if can_write(bs) is true. */
|
|
bm->flags |= BME_FLAG_IN_USE;
|
|
needs_update = true;
|
|
}
|
|
if (!(bm->flags & BME_FLAG_AUTO)) {
|
|
bdrv_disable_dirty_bitmap(bitmap);
|
|
}
|
|
created_dirty_bitmaps =
|
|
g_slist_append(created_dirty_bitmaps, bitmap);
|
|
}
|
|
|
|
if (needs_update && can_write(bs)) {
|
|
/* in_use flags must be updated */
|
|
int ret = update_ext_header_and_dir_in_place(bs, bm_list);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Can't update bitmap directory");
|
|
goto fail;
|
|
}
|
|
header_updated = true;
|
|
}
|
|
|
|
if (!can_write(bs)) {
|
|
g_slist_foreach(created_dirty_bitmaps, set_readonly_helper,
|
|
(gpointer)true);
|
|
}
|
|
|
|
g_slist_free(created_dirty_bitmaps);
|
|
bitmap_list_free(bm_list);
|
|
|
|
return header_updated;
|
|
|
|
fail:
|
|
g_slist_foreach(created_dirty_bitmaps, release_dirty_bitmap_helper, bs);
|
|
g_slist_free(created_dirty_bitmaps);
|
|
bitmap_list_free(bm_list);
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
static Qcow2BitmapInfoFlagsList *get_bitmap_info_flags(uint32_t flags)
|
|
{
|
|
Qcow2BitmapInfoFlagsList *list = NULL;
|
|
Qcow2BitmapInfoFlagsList **plist = &list;
|
|
int i;
|
|
|
|
static const struct {
|
|
int bme; /* Bitmap directory entry flags */
|
|
int info; /* The flags to report to the user */
|
|
} map[] = {
|
|
{ BME_FLAG_IN_USE, QCOW2_BITMAP_INFO_FLAGS_IN_USE },
|
|
{ BME_FLAG_AUTO, QCOW2_BITMAP_INFO_FLAGS_AUTO },
|
|
};
|
|
|
|
int map_size = ARRAY_SIZE(map);
|
|
|
|
for (i = 0; i < map_size; ++i) {
|
|
if (flags & map[i].bme) {
|
|
Qcow2BitmapInfoFlagsList *entry =
|
|
g_new0(Qcow2BitmapInfoFlagsList, 1);
|
|
entry->value = map[i].info;
|
|
*plist = entry;
|
|
plist = &entry->next;
|
|
flags &= ~map[i].bme;
|
|
}
|
|
}
|
|
/* Check if the BME_* mapping above is complete */
|
|
assert(!flags);
|
|
|
|
return list;
|
|
}
|
|
|
|
/*
|
|
* qcow2_get_bitmap_info_list()
|
|
* Returns a list of QCOW2 bitmap details.
|
|
* In case of no bitmaps, the function returns NULL and
|
|
* the @errp parameter is not set.
|
|
* When bitmap information can not be obtained, the function returns
|
|
* NULL and the @errp parameter is set.
|
|
*/
|
|
Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
|
|
Error **errp)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
Qcow2BitmapList *bm_list;
|
|
Qcow2Bitmap *bm;
|
|
Qcow2BitmapInfoList *list = NULL;
|
|
Qcow2BitmapInfoList **plist = &list;
|
|
|
|
if (s->nb_bitmaps == 0) {
|
|
return NULL;
|
|
}
|
|
|
|
bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
|
|
s->bitmap_directory_size, errp);
|
|
if (bm_list == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
Qcow2BitmapInfo *info = g_new0(Qcow2BitmapInfo, 1);
|
|
Qcow2BitmapInfoList *obj = g_new0(Qcow2BitmapInfoList, 1);
|
|
info->granularity = 1U << bm->granularity_bits;
|
|
info->name = g_strdup(bm->name);
|
|
info->flags = get_bitmap_info_flags(bm->flags & ~BME_RESERVED_FLAGS);
|
|
obj->value = info;
|
|
*plist = obj;
|
|
plist = &obj->next;
|
|
}
|
|
|
|
bitmap_list_free(bm_list);
|
|
|
|
return list;
|
|
}
|
|
|
|
int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
Qcow2BitmapList *bm_list;
|
|
Qcow2Bitmap *bm;
|
|
GSList *ro_dirty_bitmaps = NULL;
|
|
int ret = -EINVAL;
|
|
bool need_header_update = false;
|
|
|
|
if (s->nb_bitmaps == 0) {
|
|
/* No bitmaps - nothing to do */
|
|
return 0;
|
|
}
|
|
|
|
bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
|
|
s->bitmap_directory_size, errp);
|
|
if (bm_list == NULL) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name);
|
|
|
|
if (!bitmap) {
|
|
error_setg(errp, "Unexpected bitmap '%s' in image '%s'",
|
|
bm->name, bs->filename);
|
|
goto out;
|
|
}
|
|
|
|
if (!(bm->flags & BME_FLAG_IN_USE)) {
|
|
if (!bdrv_dirty_bitmap_readonly(bitmap)) {
|
|
error_setg(errp, "Corruption: bitmap '%s' is not marked IN_USE "
|
|
"in the image '%s' and not marked readonly in RAM",
|
|
bm->name, bs->filename);
|
|
goto out;
|
|
}
|
|
if (bdrv_dirty_bitmap_inconsistent(bitmap)) {
|
|
error_setg(errp, "Corruption: bitmap '%s' is inconsistent but "
|
|
"is not marked IN_USE in the image '%s'", bm->name,
|
|
bs->filename);
|
|
goto out;
|
|
}
|
|
|
|
bm->flags |= BME_FLAG_IN_USE;
|
|
need_header_update = true;
|
|
} else {
|
|
/*
|
|
* What if flags already has BME_FLAG_IN_USE ?
|
|
*
|
|
* 1. if we are reopening RW -> RW it's OK, of course.
|
|
* 2. if we are reopening RO -> RW:
|
|
* 2.1 if @bitmap is inconsistent, it's OK. It means that it was
|
|
* inconsistent (IN_USE) when we loaded it
|
|
* 2.2 if @bitmap is not inconsistent. This seems to be impossible
|
|
* and implies third party interaction. Let's error-out for
|
|
* safety.
|
|
*/
|
|
if (bdrv_dirty_bitmap_readonly(bitmap) &&
|
|
!bdrv_dirty_bitmap_inconsistent(bitmap))
|
|
{
|
|
error_setg(errp, "Corruption: bitmap '%s' is marked IN_USE "
|
|
"in the image '%s' but it is readonly and "
|
|
"consistent in RAM",
|
|
bm->name, bs->filename);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (bdrv_dirty_bitmap_readonly(bitmap)) {
|
|
ro_dirty_bitmaps = g_slist_append(ro_dirty_bitmaps, bitmap);
|
|
}
|
|
}
|
|
|
|
if (need_header_update) {
|
|
if (!can_write(bs->file->bs) || !(bs->file->perm & BLK_PERM_WRITE)) {
|
|
error_setg(errp, "Failed to reopen bitmaps rw: no write access "
|
|
"the protocol file");
|
|
goto out;
|
|
}
|
|
|
|
/* in_use flags must be updated */
|
|
ret = update_ext_header_and_dir_in_place(bs, bm_list);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Cannot update bitmap directory");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
g_slist_foreach(ro_dirty_bitmaps, set_readonly_helper, false);
|
|
ret = 0;
|
|
|
|
out:
|
|
g_slist_free(ro_dirty_bitmaps);
|
|
bitmap_list_free(bm_list);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Checks to see if it's safe to resize bitmaps */
|
|
int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
Qcow2BitmapList *bm_list;
|
|
Qcow2Bitmap *bm;
|
|
int ret = 0;
|
|
|
|
if (s->nb_bitmaps == 0) {
|
|
return 0;
|
|
}
|
|
|
|
bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
|
|
s->bitmap_directory_size, errp);
|
|
if (bm_list == NULL) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name);
|
|
if (bitmap == NULL) {
|
|
/*
|
|
* We rely on all bitmaps being in-memory to be able to resize them,
|
|
* Otherwise, we'd need to resize them on disk explicitly
|
|
*/
|
|
error_setg(errp, "Cannot resize qcow2 with persistent bitmaps that "
|
|
"were not loaded into memory");
|
|
ret = -ENOTSUP;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* The checks against readonly and busy are redundant, but certainly
|
|
* do no harm. checks against inconsistent are crucial:
|
|
*/
|
|
if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) {
|
|
ret = -ENOTSUP;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
bitmap_list_free(bm_list);
|
|
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 **errp)
|
|
{
|
|
int ret;
|
|
BDRVQcow2State *s = bs->opaque;
|
|
int64_t offset;
|
|
uint64_t limit;
|
|
uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
|
|
const char *bm_name = bdrv_dirty_bitmap_name(bitmap);
|
|
uint8_t *buf = NULL;
|
|
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;
|
|
}
|
|
|
|
buf = g_malloc(s->cluster_size);
|
|
limit = bytes_covered_by_bitmap_cluster(s, bitmap);
|
|
assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
|
|
|
|
offset = 0;
|
|
while ((offset = bdrv_dirty_bitmap_next_dirty(bitmap, offset, INT64_MAX))
|
|
>= 0)
|
|
{
|
|
uint64_t cluster = offset / limit;
|
|
uint64_t end, write_size;
|
|
int64_t off;
|
|
|
|
/*
|
|
* We found the first dirty offset, but want to write out the
|
|
* entire cluster of the bitmap that includes that offset,
|
|
* including any leading zero bits.
|
|
*/
|
|
offset = QEMU_ALIGN_DOWN(offset, limit);
|
|
end = MIN(bm_size, offset + limit);
|
|
write_size = bdrv_dirty_bitmap_serialization_size(bitmap, offset,
|
|
end - offset);
|
|
assert(write_size <= s->cluster_size);
|
|
|
|
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, offset, end - offset);
|
|
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, false);
|
|
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;
|
|
}
|
|
|
|
offset = end;
|
|
}
|
|
|
|
*bitmap_table_size = tb_size;
|
|
g_free(buf);
|
|
|
|
return tb;
|
|
|
|
fail:
|
|
clear_bitmap_table(bs, tb, tb_size);
|
|
g_free(buf);
|
|
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) {
|
|
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);
|
|
ret = tb_offset;
|
|
goto fail;
|
|
}
|
|
|
|
ret = qcow2_pre_write_overlap_check(bs, 0, tb_offset,
|
|
tb_size * sizeof(tb[0]), false);
|
|
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 * 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) == 0) {
|
|
return bm;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int coroutine_fn qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
|
|
const char *name,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BDRVQcow2State *s = bs->opaque;
|
|
Qcow2Bitmap *bm = NULL;
|
|
Qcow2BitmapList *bm_list;
|
|
|
|
if (s->nb_bitmaps == 0) {
|
|
/*
|
|
* Absence of the bitmap is not an error: see explanation above
|
|
* bdrv_co_remove_persistent_dirty_bitmap() definition.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
|
|
bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
|
|
s->bitmap_directory_size, errp);
|
|
if (bm_list == NULL) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
bm = find_bitmap_by_name(bm_list, name);
|
|
if (bm == NULL) {
|
|
/* Absence of the bitmap is not an error, see above. */
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
QSIMPLEQ_REMOVE(bm_list, bm, Qcow2Bitmap, entry);
|
|
|
|
ret = update_ext_header_and_dir(bs, bm_list);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Failed to update bitmap extension");
|
|
goto out;
|
|
}
|
|
|
|
free_bitmap_clusters(bs, &bm->table);
|
|
|
|
out:
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
bitmap_free(bm);
|
|
bitmap_list_free(bm_list);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* qcow2_store_persistent_dirty_bitmaps
|
|
*
|
|
* Stores persistent BdrvDirtyBitmap objects.
|
|
*
|
|
* @release_stored: if true, release BdrvDirtyBitmap's after storing to the
|
|
* image. This is used in two cases, both via qcow2_inactivate:
|
|
* 1. bdrv_close: It's correct to remove bitmaps on close.
|
|
* 2. migration: If bitmaps are migrated through migration channel via
|
|
* 'dirty-bitmaps' migration capability they are not handled by this code.
|
|
* Otherwise, it's OK to drop BdrvDirtyBitmap's and reload them on
|
|
* invalidation.
|
|
*
|
|
* Anyway, it's correct to remove BdrvDirtyBitmap's on inactivation, as
|
|
* inactivation means that we lose control on disk, and therefore on bitmaps,
|
|
* we should sync them and do not touch more.
|
|
*
|
|
* Contrariwise, we don't want to release any bitmaps on just reopen-to-ro,
|
|
* when we need to store them, as image is still under our control, and it's
|
|
* good to keep all the bitmaps in read-only mode. Moreover, keeping them
|
|
* read-only is correct because this is what would happen if we opened the node
|
|
* readonly to begin with, and whether we opened directly or reopened to that
|
|
* state shouldn't matter for the state we get afterward.
|
|
*/
|
|
void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
|
|
bool release_stored, 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;
|
|
QSIMPLEQ_HEAD(, Qcow2BitmapTable) drop_tables;
|
|
Qcow2BitmapTable *tb, *tb_next;
|
|
bool need_write = false;
|
|
|
|
QSIMPLEQ_INIT(&drop_tables);
|
|
|
|
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) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* check constraints and names */
|
|
FOR_EACH_DIRTY_BITMAP(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_persistence(bitmap) ||
|
|
bdrv_dirty_bitmap_inconsistent(bitmap)) {
|
|
continue;
|
|
}
|
|
|
|
if (bdrv_dirty_bitmap_readonly(bitmap)) {
|
|
/*
|
|
* Store the bitmap in the associated Qcow2Bitmap so it
|
|
* can be released later
|
|
*/
|
|
bm = find_bitmap_by_name(bm_list, name);
|
|
if (bm) {
|
|
bm->dirty_bitmap = bitmap;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
need_write = true;
|
|
|
|
if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) {
|
|
error_prepend(errp, "Bitmap '%s' doesn't satisfy the constraints: ",
|
|
name);
|
|
goto fail;
|
|
}
|
|
|
|
bm = find_bitmap_by_name(bm_list, name);
|
|
if (bm == NULL) {
|
|
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, "Bitmap directory is too large");
|
|
goto fail;
|
|
}
|
|
|
|
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)) {
|
|
error_setg(errp, "Bitmap '%s' already exists in the image",
|
|
name);
|
|
goto fail;
|
|
}
|
|
tb = g_memdup(&bm->table, sizeof(bm->table));
|
|
bm->table.offset = 0;
|
|
bm->table.size = 0;
|
|
QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry);
|
|
}
|
|
bm->flags = bdrv_dirty_bitmap_enabled(bitmap) ? BME_FLAG_AUTO : 0;
|
|
bm->granularity_bits = ctz32(bdrv_dirty_bitmap_granularity(bitmap));
|
|
bm->dirty_bitmap = bitmap;
|
|
}
|
|
|
|
if (!need_write) {
|
|
goto success;
|
|
}
|
|
|
|
if (!can_write(bs)) {
|
|
error_setg(errp, "No write access");
|
|
goto fail;
|
|
}
|
|
|
|
/* allocate clusters and store bitmaps */
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
BdrvDirtyBitmap *bitmap = bm->dirty_bitmap;
|
|
|
|
if (bitmap == NULL || bdrv_dirty_bitmap_readonly(bitmap)) {
|
|
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 directory was successfully updated, so, old data can be dropped.
|
|
* 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);
|
|
}
|
|
|
|
success:
|
|
if (release_stored) {
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
if (bm->dirty_bitmap == NULL) {
|
|
continue;
|
|
}
|
|
|
|
bdrv_release_dirty_bitmap(bm->dirty_bitmap);
|
|
}
|
|
}
|
|
|
|
bitmap_list_free(bm_list);
|
|
return;
|
|
|
|
fail:
|
|
QSIMPLEQ_FOREACH(bm, bm_list, entry) {
|
|
if (bm->dirty_bitmap == NULL || bm->table.offset == 0 ||
|
|
bdrv_dirty_bitmap_readonly(bm->dirty_bitmap))
|
|
{
|
|
continue;
|
|
}
|
|
|
|
free_bitmap_clusters(bs, &bm->table);
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) {
|
|
g_free(tb);
|
|
}
|
|
|
|
bitmap_list_free(bm_list);
|
|
}
|
|
|
|
int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BdrvDirtyBitmap *bitmap;
|
|
Error *local_err = NULL;
|
|
|
|
qcow2_store_persistent_dirty_bitmaps(bs, false, &local_err);
|
|
if (local_err != NULL) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
|
|
if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
|
|
bdrv_dirty_bitmap_set_readonly(bitmap, true);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool coroutine_fn qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
|
|
const char *name,
|
|
uint32_t granularity,
|
|
Error **errp)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
BdrvDirtyBitmap *bitmap;
|
|
uint64_t bitmap_directory_size = 0;
|
|
uint32_t nb_bitmaps = 0;
|
|
|
|
if (bdrv_find_dirty_bitmap(bs, name)) {
|
|
error_setg(errp, "Bitmap already exists: %s", name);
|
|
return false;
|
|
}
|
|
|
|
if (s->qcow_version < 3) {
|
|
/* Without autoclear_features, we would always have to assume
|
|
* that a program without persistent dirty bitmap support has
|
|
* accessed this qcow2 file when opening it, and would thus
|
|
* have to drop all dirty bitmaps (defeating their purpose).
|
|
*/
|
|
error_setg(errp, "Cannot store dirty bitmaps in qcow2 v2 files");
|
|
goto fail;
|
|
}
|
|
|
|
if (check_constraints_on_bitmap(bs, name, granularity, errp) != 0) {
|
|
goto fail;
|
|
}
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
|
|
if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
|
|
nb_bitmaps++;
|
|
bitmap_directory_size +=
|
|
calc_dir_entry_size(strlen(bdrv_dirty_bitmap_name(bitmap)), 0);
|
|
}
|
|
}
|
|
nb_bitmaps++;
|
|
bitmap_directory_size += calc_dir_entry_size(strlen(name), 0);
|
|
|
|
if (nb_bitmaps > QCOW2_MAX_BITMAPS) {
|
|
error_setg(errp,
|
|
"Maximum number of persistent bitmaps is already reached");
|
|
goto fail;
|
|
}
|
|
|
|
if (bitmap_directory_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) {
|
|
error_setg(errp, "Not enough space in the bitmap directory");
|
|
goto fail;
|
|
}
|
|
|
|
return true;
|
|
|
|
fail:
|
|
error_prepend(errp, "Can't make bitmap '%s' persistent in '%s': ",
|
|
name, bdrv_get_device_or_node_name(bs));
|
|
return false;
|
|
}
|
|
|
|
bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs)
|
|
{
|
|
BDRVQcow2State *s = bs->opaque;
|
|
|
|
return s->qcow_version >= 3;
|
|
}
|
|
|
|
/*
|
|
* Compute the space required to copy bitmaps from @in_bs.
|
|
*
|
|
* The computation is based as if copying to a new image with the
|
|
* given @cluster_size, which may differ from the cluster size in
|
|
* @in_bs; in fact, @in_bs might be something other than qcow2.
|
|
*/
|
|
uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *in_bs,
|
|
uint32_t cluster_size)
|
|
{
|
|
uint64_t bitmaps_size = 0;
|
|
BdrvDirtyBitmap *bm;
|
|
size_t bitmap_dir_size = 0;
|
|
|
|
FOR_EACH_DIRTY_BITMAP(in_bs, bm) {
|
|
if (bdrv_dirty_bitmap_get_persistence(bm)) {
|
|
const char *name = bdrv_dirty_bitmap_name(bm);
|
|
uint32_t granularity = bdrv_dirty_bitmap_granularity(bm);
|
|
uint64_t bmbytes =
|
|
get_bitmap_bytes_needed(bdrv_dirty_bitmap_size(bm),
|
|
granularity);
|
|
uint64_t bmclusters = DIV_ROUND_UP(bmbytes, cluster_size);
|
|
|
|
/* Assume the entire bitmap is allocated */
|
|
bitmaps_size += bmclusters * cluster_size;
|
|
/* Also reserve space for the bitmap table entries */
|
|
bitmaps_size += ROUND_UP(bmclusters * sizeof(uint64_t),
|
|
cluster_size);
|
|
/* And space for contribution to bitmap directory size */
|
|
bitmap_dir_size += calc_dir_entry_size(strlen(name), 0);
|
|
}
|
|
}
|
|
bitmaps_size += ROUND_UP(bitmap_dir_size, cluster_size);
|
|
|
|
return bitmaps_size;
|
|
}
|