qed: Add QEMU Enhanced Disk image format
This patch introduces the qed on-disk layout and implements image creation. Later patches add read/write and other functionality. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi
Kevin Wolf
parent
71af014f14
commit
75411d236d
@ -20,6 +20,7 @@ block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
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block-nested-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o
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block-nested-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o
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block-nested-y += qed.o
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block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o
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block-nested-$(CONFIG_WIN32) += raw-win32.o
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block-nested-$(CONFIG_POSIX) += raw-posix.o
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554
block/qed.c
Normal file
554
block/qed.c
Normal file
@ -0,0 +1,554 @@
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/*
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* QEMU Enhanced Disk Format
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*
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* Copyright IBM, Corp. 2010
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*
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* Authors:
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qed.h"
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static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
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const char *filename)
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{
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const QEDHeader *header = (const QEDHeader *)buf;
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if (buf_size < sizeof(*header)) {
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return 0;
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}
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if (le32_to_cpu(header->magic) != QED_MAGIC) {
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return 0;
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}
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return 100;
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}
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/**
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* Check whether an image format is raw
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*
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* @fmt: Backing file format, may be NULL
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*/
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static bool qed_fmt_is_raw(const char *fmt)
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{
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return fmt && strcmp(fmt, "raw") == 0;
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}
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static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu)
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{
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cpu->magic = le32_to_cpu(le->magic);
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cpu->cluster_size = le32_to_cpu(le->cluster_size);
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cpu->table_size = le32_to_cpu(le->table_size);
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cpu->header_size = le32_to_cpu(le->header_size);
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cpu->features = le64_to_cpu(le->features);
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cpu->compat_features = le64_to_cpu(le->compat_features);
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cpu->autoclear_features = le64_to_cpu(le->autoclear_features);
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cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset);
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cpu->image_size = le64_to_cpu(le->image_size);
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cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset);
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cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size);
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}
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static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
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{
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le->magic = cpu_to_le32(cpu->magic);
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le->cluster_size = cpu_to_le32(cpu->cluster_size);
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le->table_size = cpu_to_le32(cpu->table_size);
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le->header_size = cpu_to_le32(cpu->header_size);
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le->features = cpu_to_le64(cpu->features);
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le->compat_features = cpu_to_le64(cpu->compat_features);
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le->autoclear_features = cpu_to_le64(cpu->autoclear_features);
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le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset);
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le->image_size = cpu_to_le64(cpu->image_size);
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le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset);
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le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size);
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}
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static int qed_write_header_sync(BDRVQEDState *s)
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{
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QEDHeader le;
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int ret;
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qed_header_cpu_to_le(&s->header, &le);
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ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le));
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if (ret != sizeof(le)) {
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return ret;
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}
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return 0;
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}
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static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
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{
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uint64_t table_entries;
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uint64_t l2_size;
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table_entries = (table_size * cluster_size) / sizeof(uint64_t);
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l2_size = table_entries * cluster_size;
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return l2_size * table_entries;
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}
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static bool qed_is_cluster_size_valid(uint32_t cluster_size)
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{
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if (cluster_size < QED_MIN_CLUSTER_SIZE ||
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cluster_size > QED_MAX_CLUSTER_SIZE) {
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return false;
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}
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if (cluster_size & (cluster_size - 1)) {
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return false; /* not power of 2 */
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}
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return true;
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}
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static bool qed_is_table_size_valid(uint32_t table_size)
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{
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if (table_size < QED_MIN_TABLE_SIZE ||
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table_size > QED_MAX_TABLE_SIZE) {
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return false;
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}
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if (table_size & (table_size - 1)) {
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return false; /* not power of 2 */
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}
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return true;
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}
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static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size,
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uint32_t table_size)
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{
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if (image_size % BDRV_SECTOR_SIZE != 0) {
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return false; /* not multiple of sector size */
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}
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if (image_size > qed_max_image_size(cluster_size, table_size)) {
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return false; /* image is too large */
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}
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return true;
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}
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/**
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* Read a string of known length from the image file
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*
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* @file: Image file
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* @offset: File offset to start of string, in bytes
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* @n: String length in bytes
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* @buf: Destination buffer
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* @buflen: Destination buffer length in bytes
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* @ret: 0 on success, -errno on failure
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*
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* The string is NUL-terminated.
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*/
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static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n,
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char *buf, size_t buflen)
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{
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int ret;
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if (n >= buflen) {
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return -EINVAL;
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}
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ret = bdrv_pread(file, offset, buf, n);
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if (ret < 0) {
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return ret;
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}
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buf[n] = '\0';
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return 0;
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}
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static int bdrv_qed_open(BlockDriverState *bs, int flags)
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{
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BDRVQEDState *s = bs->opaque;
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QEDHeader le_header;
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int64_t file_size;
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int ret;
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s->bs = bs;
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ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header));
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if (ret < 0) {
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return ret;
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}
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ret = 0; /* ret should always be 0 or -errno */
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qed_header_le_to_cpu(&le_header, &s->header);
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if (s->header.magic != QED_MAGIC) {
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return -EINVAL;
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}
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if (s->header.features & ~QED_FEATURE_MASK) {
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return -ENOTSUP; /* image uses unsupported feature bits */
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}
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if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
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return -EINVAL;
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}
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/* Round down file size to the last cluster */
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file_size = bdrv_getlength(bs->file);
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if (file_size < 0) {
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return file_size;
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}
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s->file_size = qed_start_of_cluster(s, file_size);
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if (!qed_is_table_size_valid(s->header.table_size)) {
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return -EINVAL;
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}
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if (!qed_is_image_size_valid(s->header.image_size,
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s->header.cluster_size,
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s->header.table_size)) {
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return -EINVAL;
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}
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if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
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return -EINVAL;
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}
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s->table_nelems = (s->header.cluster_size * s->header.table_size) /
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sizeof(uint64_t);
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s->l2_shift = ffs(s->header.cluster_size) - 1;
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s->l2_mask = s->table_nelems - 1;
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s->l1_shift = s->l2_shift + ffs(s->table_nelems) - 1;
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if ((s->header.features & QED_F_BACKING_FILE)) {
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if ((uint64_t)s->header.backing_filename_offset +
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s->header.backing_filename_size >
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s->header.cluster_size * s->header.header_size) {
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return -EINVAL;
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}
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ret = qed_read_string(bs->file, s->header.backing_filename_offset,
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s->header.backing_filename_size, bs->backing_file,
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sizeof(bs->backing_file));
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if (ret < 0) {
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return ret;
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}
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if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
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pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
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}
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}
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/* Reset unknown autoclear feature bits. This is a backwards
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* compatibility mechanism that allows images to be opened by older
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* programs, which "knock out" unknown feature bits. When an image is
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* opened by a newer program again it can detect that the autoclear
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* feature is no longer valid.
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*/
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if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 &&
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!bdrv_is_read_only(bs->file)) {
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s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK;
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ret = qed_write_header_sync(s);
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if (ret) {
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return ret;
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}
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/* From here on only known autoclear feature bits are valid */
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bdrv_flush(bs->file);
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}
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return ret;
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}
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static void bdrv_qed_close(BlockDriverState *bs)
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{
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}
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static int bdrv_qed_flush(BlockDriverState *bs)
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{
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return bdrv_flush(bs->file);
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}
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static int qed_create(const char *filename, uint32_t cluster_size,
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uint64_t image_size, uint32_t table_size,
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const char *backing_file, const char *backing_fmt)
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{
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QEDHeader header = {
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.magic = QED_MAGIC,
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.cluster_size = cluster_size,
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.table_size = table_size,
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.header_size = 1,
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.features = 0,
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.compat_features = 0,
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.l1_table_offset = cluster_size,
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.image_size = image_size,
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};
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QEDHeader le_header;
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uint8_t *l1_table = NULL;
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size_t l1_size = header.cluster_size * header.table_size;
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int ret = 0;
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BlockDriverState *bs = NULL;
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ret = bdrv_create_file(filename, NULL);
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if (ret < 0) {
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return ret;
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}
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ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR | BDRV_O_CACHE_WB);
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if (ret < 0) {
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return ret;
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}
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if (backing_file) {
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header.features |= QED_F_BACKING_FILE;
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header.backing_filename_offset = sizeof(le_header);
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header.backing_filename_size = strlen(backing_file);
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if (qed_fmt_is_raw(backing_fmt)) {
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header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
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}
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}
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qed_header_cpu_to_le(&header, &le_header);
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ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header));
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if (ret < 0) {
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goto out;
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}
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ret = bdrv_pwrite(bs, sizeof(le_header), backing_file,
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header.backing_filename_size);
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if (ret < 0) {
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goto out;
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}
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l1_table = qemu_mallocz(l1_size);
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ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size);
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if (ret < 0) {
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goto out;
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}
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ret = 0; /* success */
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out:
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qemu_free(l1_table);
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bdrv_delete(bs);
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return ret;
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}
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static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options)
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{
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uint64_t image_size = 0;
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uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE;
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uint32_t table_size = QED_DEFAULT_TABLE_SIZE;
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const char *backing_file = NULL;
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const char *backing_fmt = NULL;
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while (options && options->name) {
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if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
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image_size = options->value.n;
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} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
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backing_file = options->value.s;
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} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
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backing_fmt = options->value.s;
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} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
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if (options->value.n) {
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cluster_size = options->value.n;
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}
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} else if (!strcmp(options->name, BLOCK_OPT_TABLE_SIZE)) {
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if (options->value.n) {
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table_size = options->value.n;
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}
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}
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options++;
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}
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if (!qed_is_cluster_size_valid(cluster_size)) {
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fprintf(stderr, "QED cluster size must be within range [%u, %u] and power of 2\n",
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QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE);
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return -EINVAL;
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}
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if (!qed_is_table_size_valid(table_size)) {
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fprintf(stderr, "QED table size must be within range [%u, %u] and power of 2\n",
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QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE);
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return -EINVAL;
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}
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if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) {
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fprintf(stderr, "QED image size must be a non-zero multiple of "
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"cluster size and less than %" PRIu64 " bytes\n",
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qed_max_image_size(cluster_size, table_size));
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return -EINVAL;
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}
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return qed_create(filename, cluster_size, image_size, table_size,
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backing_file, backing_fmt);
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}
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static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, int *pnum)
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{
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return -ENOTSUP;
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}
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static int bdrv_qed_make_empty(BlockDriverState *bs)
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{
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return -ENOTSUP;
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}
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static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs,
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int64_t sector_num,
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QEMUIOVector *qiov, int nb_sectors,
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BlockDriverCompletionFunc *cb,
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void *opaque)
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{
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return NULL;
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}
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static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs,
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int64_t sector_num,
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QEMUIOVector *qiov, int nb_sectors,
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BlockDriverCompletionFunc *cb,
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void *opaque)
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{
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return NULL;
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}
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static BlockDriverAIOCB *bdrv_qed_aio_flush(BlockDriverState *bs,
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BlockDriverCompletionFunc *cb,
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void *opaque)
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{
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return bdrv_aio_flush(bs->file, cb, opaque);
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}
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static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset)
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{
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return -ENOTSUP;
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}
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static int64_t bdrv_qed_getlength(BlockDriverState *bs)
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{
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BDRVQEDState *s = bs->opaque;
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return s->header.image_size;
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}
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static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
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{
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BDRVQEDState *s = bs->opaque;
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memset(bdi, 0, sizeof(*bdi));
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bdi->cluster_size = s->header.cluster_size;
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return 0;
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}
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static int bdrv_qed_change_backing_file(BlockDriverState *bs,
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const char *backing_file,
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const char *backing_fmt)
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{
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BDRVQEDState *s = bs->opaque;
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QEDHeader new_header, le_header;
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void *buffer;
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size_t buffer_len, backing_file_len;
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int ret;
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/* Refuse to set backing filename if unknown compat feature bits are
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* active. If the image uses an unknown compat feature then we may not
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* know the layout of data following the header structure and cannot safely
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* add a new string.
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*/
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if (backing_file && (s->header.compat_features &
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~QED_COMPAT_FEATURE_MASK)) {
|
||||
return -ENOTSUP;
|
||||
}
|
||||
|
||||
memcpy(&new_header, &s->header, sizeof(new_header));
|
||||
|
||||
new_header.features &= ~(QED_F_BACKING_FILE |
|
||||
QED_F_BACKING_FORMAT_NO_PROBE);
|
||||
|
||||
/* Adjust feature flags */
|
||||
if (backing_file) {
|
||||
new_header.features |= QED_F_BACKING_FILE;
|
||||
|
||||
if (qed_fmt_is_raw(backing_fmt)) {
|
||||
new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
|
||||
}
|
||||
}
|
||||
|
||||
/* Calculate new header size */
|
||||
backing_file_len = 0;
|
||||
|
||||
if (backing_file) {
|
||||
backing_file_len = strlen(backing_file);
|
||||
}
|
||||
|
||||
buffer_len = sizeof(new_header);
|
||||
new_header.backing_filename_offset = buffer_len;
|
||||
new_header.backing_filename_size = backing_file_len;
|
||||
buffer_len += backing_file_len;
|
||||
|
||||
/* Make sure we can rewrite header without failing */
|
||||
if (buffer_len > new_header.header_size * new_header.cluster_size) {
|
||||
return -ENOSPC;
|
||||
}
|
||||
|
||||
/* Prepare new header */
|
||||
buffer = qemu_malloc(buffer_len);
|
||||
|
||||
qed_header_cpu_to_le(&new_header, &le_header);
|
||||
memcpy(buffer, &le_header, sizeof(le_header));
|
||||
buffer_len = sizeof(le_header);
|
||||
|
||||
memcpy(buffer + buffer_len, backing_file, backing_file_len);
|
||||
buffer_len += backing_file_len;
|
||||
|
||||
/* Write new header */
|
||||
ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
|
||||
qemu_free(buffer);
|
||||
if (ret == 0) {
|
||||
memcpy(&s->header, &new_header, sizeof(new_header));
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result)
|
||||
{
|
||||
return -ENOTSUP;
|
||||
}
|
||||
|
||||
static QEMUOptionParameter qed_create_options[] = {
|
||||
{
|
||||
.name = BLOCK_OPT_SIZE,
|
||||
.type = OPT_SIZE,
|
||||
.help = "Virtual disk size (in bytes)"
|
||||
}, {
|
||||
.name = BLOCK_OPT_BACKING_FILE,
|
||||
.type = OPT_STRING,
|
||||
.help = "File name of a base image"
|
||||
}, {
|
||||
.name = BLOCK_OPT_BACKING_FMT,
|
||||
.type = OPT_STRING,
|
||||
.help = "Image format of the base image"
|
||||
}, {
|
||||
.name = BLOCK_OPT_CLUSTER_SIZE,
|
||||
.type = OPT_SIZE,
|
||||
.help = "Cluster size (in bytes)"
|
||||
}, {
|
||||
.name = BLOCK_OPT_TABLE_SIZE,
|
||||
.type = OPT_SIZE,
|
||||
.help = "L1/L2 table size (in clusters)"
|
||||
},
|
||||
{ /* end of list */ }
|
||||
};
|
||||
|
||||
static BlockDriver bdrv_qed = {
|
||||
.format_name = "qed",
|
||||
.instance_size = sizeof(BDRVQEDState),
|
||||
.create_options = qed_create_options,
|
||||
|
||||
.bdrv_probe = bdrv_qed_probe,
|
||||
.bdrv_open = bdrv_qed_open,
|
||||
.bdrv_close = bdrv_qed_close,
|
||||
.bdrv_create = bdrv_qed_create,
|
||||
.bdrv_flush = bdrv_qed_flush,
|
||||
.bdrv_is_allocated = bdrv_qed_is_allocated,
|
||||
.bdrv_make_empty = bdrv_qed_make_empty,
|
||||
.bdrv_aio_readv = bdrv_qed_aio_readv,
|
||||
.bdrv_aio_writev = bdrv_qed_aio_writev,
|
||||
.bdrv_aio_flush = bdrv_qed_aio_flush,
|
||||
.bdrv_truncate = bdrv_qed_truncate,
|
||||
.bdrv_getlength = bdrv_qed_getlength,
|
||||
.bdrv_get_info = bdrv_qed_get_info,
|
||||
.bdrv_change_backing_file = bdrv_qed_change_backing_file,
|
||||
.bdrv_check = bdrv_qed_check,
|
||||
};
|
||||
|
||||
static void bdrv_qed_init(void)
|
||||
{
|
||||
bdrv_register(&bdrv_qed);
|
||||
}
|
||||
|
||||
block_init(bdrv_qed_init);
|
||||
148
block/qed.h
Normal file
148
block/qed.h
Normal file
@ -0,0 +1,148 @@
|
||||
/*
|
||||
* QEMU Enhanced Disk Format
|
||||
*
|
||||
* Copyright IBM, Corp. 2010
|
||||
*
|
||||
* Authors:
|
||||
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
|
||||
* Anthony Liguori <aliguori@us.ibm.com>
|
||||
*
|
||||
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
|
||||
* See the COPYING.LIB file in the top-level directory.
|
||||
*
|
||||
*/
|
||||
|
||||
#ifndef BLOCK_QED_H
|
||||
#define BLOCK_QED_H
|
||||
|
||||
#include "block_int.h"
|
||||
|
||||
/* The layout of a QED file is as follows:
|
||||
*
|
||||
* +--------+----------+----------+----------+-----+
|
||||
* | header | L1 table | cluster0 | cluster1 | ... |
|
||||
* +--------+----------+----------+----------+-----+
|
||||
*
|
||||
* There is a 2-level pagetable for cluster allocation:
|
||||
*
|
||||
* +----------+
|
||||
* | L1 table |
|
||||
* +----------+
|
||||
* ,------' | '------.
|
||||
* +----------+ | +----------+
|
||||
* | L2 table | ... | L2 table |
|
||||
* +----------+ +----------+
|
||||
* ,------' | '------.
|
||||
* +----------+ | +----------+
|
||||
* | Data | ... | Data |
|
||||
* +----------+ +----------+
|
||||
*
|
||||
* The L1 table is fixed size and always present. L2 tables are allocated on
|
||||
* demand. The L1 table size determines the maximum possible image size; it
|
||||
* can be influenced using the cluster_size and table_size values.
|
||||
*
|
||||
* All fields are little-endian on disk.
|
||||
*/
|
||||
|
||||
enum {
|
||||
QED_MAGIC = 'Q' | 'E' << 8 | 'D' << 16 | '\0' << 24,
|
||||
|
||||
/* The image supports a backing file */
|
||||
QED_F_BACKING_FILE = 0x01,
|
||||
|
||||
/* The backing file format must not be probed, treat as raw image */
|
||||
QED_F_BACKING_FORMAT_NO_PROBE = 0x04,
|
||||
|
||||
/* Feature bits must be used when the on-disk format changes */
|
||||
QED_FEATURE_MASK = QED_F_BACKING_FILE | /* supported feature bits */
|
||||
QED_F_BACKING_FORMAT_NO_PROBE,
|
||||
QED_COMPAT_FEATURE_MASK = 0, /* supported compat feature bits */
|
||||
QED_AUTOCLEAR_FEATURE_MASK = 0, /* supported autoclear feature bits */
|
||||
|
||||
/* Data is stored in groups of sectors called clusters. Cluster size must
|
||||
* be large to avoid keeping too much metadata. I/O requests that have
|
||||
* sub-cluster size will require read-modify-write.
|
||||
*/
|
||||
QED_MIN_CLUSTER_SIZE = 4 * 1024, /* in bytes */
|
||||
QED_MAX_CLUSTER_SIZE = 64 * 1024 * 1024,
|
||||
QED_DEFAULT_CLUSTER_SIZE = 64 * 1024,
|
||||
|
||||
/* Allocated clusters are tracked using a 2-level pagetable. Table size is
|
||||
* a multiple of clusters so large maximum image sizes can be supported
|
||||
* without jacking up the cluster size too much.
|
||||
*/
|
||||
QED_MIN_TABLE_SIZE = 1, /* in clusters */
|
||||
QED_MAX_TABLE_SIZE = 16,
|
||||
QED_DEFAULT_TABLE_SIZE = 4,
|
||||
};
|
||||
|
||||
typedef struct {
|
||||
uint32_t magic; /* QED\0 */
|
||||
|
||||
uint32_t cluster_size; /* in bytes */
|
||||
uint32_t table_size; /* for L1 and L2 tables, in clusters */
|
||||
uint32_t header_size; /* in clusters */
|
||||
|
||||
uint64_t features; /* format feature bits */
|
||||
uint64_t compat_features; /* compatible feature bits */
|
||||
uint64_t autoclear_features; /* self-resetting feature bits */
|
||||
|
||||
uint64_t l1_table_offset; /* in bytes */
|
||||
uint64_t image_size; /* total logical image size, in bytes */
|
||||
|
||||
/* if (features & QED_F_BACKING_FILE) */
|
||||
uint32_t backing_filename_offset; /* in bytes from start of header */
|
||||
uint32_t backing_filename_size; /* in bytes */
|
||||
} QEDHeader;
|
||||
|
||||
typedef struct {
|
||||
BlockDriverState *bs; /* device */
|
||||
uint64_t file_size; /* length of image file, in bytes */
|
||||
|
||||
QEDHeader header; /* always cpu-endian */
|
||||
uint32_t table_nelems;
|
||||
uint32_t l1_shift;
|
||||
uint32_t l2_shift;
|
||||
uint32_t l2_mask;
|
||||
} BDRVQEDState;
|
||||
|
||||
/**
|
||||
* Round down to the start of a cluster
|
||||
*/
|
||||
static inline uint64_t qed_start_of_cluster(BDRVQEDState *s, uint64_t offset)
|
||||
{
|
||||
return offset & ~(uint64_t)(s->header.cluster_size - 1);
|
||||
}
|
||||
|
||||
/**
|
||||
* Test if a cluster offset is valid
|
||||
*/
|
||||
static inline bool qed_check_cluster_offset(BDRVQEDState *s, uint64_t offset)
|
||||
{
|
||||
uint64_t header_size = (uint64_t)s->header.header_size *
|
||||
s->header.cluster_size;
|
||||
|
||||
if (offset & (s->header.cluster_size - 1)) {
|
||||
return false;
|
||||
}
|
||||
return offset >= header_size && offset < s->file_size;
|
||||
}
|
||||
|
||||
/**
|
||||
* Test if a table offset is valid
|
||||
*/
|
||||
static inline bool qed_check_table_offset(BDRVQEDState *s, uint64_t offset)
|
||||
{
|
||||
uint64_t end_offset = offset + (s->header.table_size - 1) *
|
||||
s->header.cluster_size;
|
||||
|
||||
/* Overflow check */
|
||||
if (end_offset <= offset) {
|
||||
return false;
|
||||
}
|
||||
|
||||
return qed_check_cluster_offset(s, offset) &&
|
||||
qed_check_cluster_offset(s, end_offset);
|
||||
}
|
||||
|
||||
#endif /* BLOCK_QED_H */
|
||||
@ -37,6 +37,7 @@
|
||||
#define BLOCK_OPT_BACKING_FILE "backing_file"
|
||||
#define BLOCK_OPT_BACKING_FMT "backing_fmt"
|
||||
#define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
|
||||
#define BLOCK_OPT_TABLE_SIZE "table_size"
|
||||
#define BLOCK_OPT_PREALLOC "preallocation"
|
||||
|
||||
typedef struct AIOPool {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user