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openwrt/tools/qemu/patches/0002-VMDK-introduce-VmdkExt...

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From fcd9c52d160376184cbd25e04586aa6eef6abd61 Mon Sep 17 00:00:00 2001
From: Fam Zheng <famcool@gmail.com>
Date: Tue, 12 Jul 2011 19:56:28 +0800
Subject: [PATCH 02/12] VMDK: introduce VmdkExtent
Introduced VmdkExtent array into BDRVVmdkState, enable holding multiple
image extents for multiple file image support.
Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/vmdk.c | 348 +++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 246 insertions(+), 102 deletions(-)
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -60,7 +60,11 @@ typedef struct {
#define L2_CACHE_SIZE 16
-typedef struct BDRVVmdkState {
+typedef struct VmdkExtent {
+ BlockDriverState *file;
+ bool flat;
+ int64_t sectors;
+ int64_t end_sector;
int64_t l1_table_offset;
int64_t l1_backup_table_offset;
uint32_t *l1_table;
@@ -74,7 +78,13 @@ typedef struct BDRVVmdkState {
uint32_t l2_cache_counts[L2_CACHE_SIZE];
unsigned int cluster_sectors;
+} VmdkExtent;
+
+typedef struct BDRVVmdkState {
uint32_t parent_cid;
+ int num_extents;
+ /* Extent array with num_extents entries, ascend ordered by address */
+ VmdkExtent *extents;
} BDRVVmdkState;
typedef struct VmdkMetaData {
@@ -105,6 +115,19 @@ static int vmdk_probe(const uint8_t *buf
#define DESC_SIZE 20*SECTOR_SIZE // 20 sectors of 512 bytes each
#define HEADER_SIZE 512 // first sector of 512 bytes
+static void vmdk_free_extents(BlockDriverState *bs)
+{
+ int i;
+ BDRVVmdkState *s = bs->opaque;
+
+ for (i = 0; i < s->num_extents; i++) {
+ qemu_free(s->extents[i].l1_table);
+ qemu_free(s->extents[i].l2_cache);
+ qemu_free(s->extents[i].l1_backup_table);
+ }
+ qemu_free(s->extents);
+}
+
static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
{
char desc[DESC_SIZE];
@@ -358,11 +381,50 @@ static int vmdk_parent_open(BlockDriverS
return 0;
}
+/* Create and append extent to the extent array. Return the added VmdkExtent
+ * address. return NULL if allocation failed. */
+static VmdkExtent *vmdk_add_extent(BlockDriverState *bs,
+ BlockDriverState *file, bool flat, int64_t sectors,
+ int64_t l1_offset, int64_t l1_backup_offset,
+ uint32_t l1_size,
+ int l2_size, unsigned int cluster_sectors)
+{
+ VmdkExtent *extent;
+ BDRVVmdkState *s = bs->opaque;
+
+ s->extents = qemu_realloc(s->extents,
+ (s->num_extents + 1) * sizeof(VmdkExtent));
+ extent = &s->extents[s->num_extents];
+ s->num_extents++;
+
+ memset(extent, 0, sizeof(VmdkExtent));
+ extent->file = file;
+ extent->flat = flat;
+ extent->sectors = sectors;
+ extent->l1_table_offset = l1_offset;
+ extent->l1_backup_table_offset = l1_backup_offset;
+ extent->l1_size = l1_size;
+ extent->l1_entry_sectors = l2_size * cluster_sectors;
+ extent->l2_size = l2_size;
+ extent->cluster_sectors = cluster_sectors;
+
+ if (s->num_extents > 1) {
+ extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
+ } else {
+ extent->end_sector = extent->sectors;
+ }
+ bs->total_sectors = extent->end_sector;
+ return extent;
+}
+
+
static int vmdk_open(BlockDriverState *bs, int flags)
{
BDRVVmdkState *s = bs->opaque;
uint32_t magic;
- int l1_size, i;
+ int i;
+ uint32_t l1_size, l1_entry_sectors;
+ VmdkExtent *extent = NULL;
if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic))
goto fail;
@@ -370,32 +432,34 @@ static int vmdk_open(BlockDriverState *b
magic = be32_to_cpu(magic);
if (magic == VMDK3_MAGIC) {
VMDK3Header header;
-
- if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header)) != sizeof(header))
+ if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header))
+ != sizeof(header)) {
goto fail;
- s->cluster_sectors = le32_to_cpu(header.granularity);
- s->l2_size = 1 << 9;
- s->l1_size = 1 << 6;
- bs->total_sectors = le32_to_cpu(header.disk_sectors);
- s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
- s->l1_backup_table_offset = 0;
- s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
+ }
+ extent = vmdk_add_extent(bs, bs->file, false,
+ le32_to_cpu(header.disk_sectors),
+ le32_to_cpu(header.l1dir_offset) << 9, 0,
+ 1 << 6, 1 << 9, le32_to_cpu(header.granularity));
} else if (magic == VMDK4_MAGIC) {
VMDK4Header header;
-
- if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header)) != sizeof(header))
+ if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header))
+ != sizeof(header)) {
goto fail;
- bs->total_sectors = le64_to_cpu(header.capacity);
- s->cluster_sectors = le64_to_cpu(header.granularity);
- s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
- s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
- if (s->l1_entry_sectors <= 0)
+ }
+ l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte)
+ * le64_to_cpu(header.granularity);
+ l1_size = (le64_to_cpu(header.capacity) + l1_entry_sectors - 1)
+ / l1_entry_sectors;
+ extent = vmdk_add_extent(bs, bs->file, false,
+ le64_to_cpu(header.capacity),
+ le64_to_cpu(header.gd_offset) << 9,
+ le64_to_cpu(header.rgd_offset) << 9,
+ l1_size,
+ le32_to_cpu(header.num_gtes_per_gte),
+ le64_to_cpu(header.granularity));
+ if (extent->l1_entry_sectors <= 0) {
goto fail;
- s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
- / s->l1_entry_sectors;
- s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
- s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
-
+ }
// try to open parent images, if exist
if (vmdk_parent_open(bs) != 0)
goto fail;
@@ -406,40 +470,49 @@ static int vmdk_open(BlockDriverState *b
}
/* read the L1 table */
- l1_size = s->l1_size * sizeof(uint32_t);
- s->l1_table = qemu_malloc(l1_size);
- if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
- goto fail;
- for(i = 0; i < s->l1_size; i++) {
- le32_to_cpus(&s->l1_table[i]);
- }
-
- if (s->l1_backup_table_offset) {
- s->l1_backup_table = qemu_malloc(l1_size);
- if (bdrv_pread(bs->file, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
+ l1_size = extent->l1_size * sizeof(uint32_t);
+ extent->l1_table = qemu_malloc(l1_size);
+ if (bdrv_pread(bs->file,
+ extent->l1_table_offset,
+ extent->l1_table,
+ l1_size)
+ != l1_size) {
+ goto fail;
+ }
+ for (i = 0; i < extent->l1_size; i++) {
+ le32_to_cpus(&extent->l1_table[i]);
+ }
+
+ if (extent->l1_backup_table_offset) {
+ extent->l1_backup_table = qemu_malloc(l1_size);
+ if (bdrv_pread(bs->file,
+ extent->l1_backup_table_offset,
+ extent->l1_backup_table,
+ l1_size)
+ != l1_size) {
goto fail;
- for(i = 0; i < s->l1_size; i++) {
- le32_to_cpus(&s->l1_backup_table[i]);
+ }
+ for (i = 0; i < extent->l1_size; i++) {
+ le32_to_cpus(&extent->l1_backup_table[i]);
}
}
- s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
+ extent->l2_cache =
+ qemu_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
return 0;
fail:
- qemu_free(s->l1_backup_table);
- qemu_free(s->l1_table);
- qemu_free(s->l2_cache);
+ vmdk_free_extents(bs);
return -1;
}
-static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
- uint64_t offset, int allocate);
-
-static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
- uint64_t offset, int allocate)
+static int get_whole_cluster(BlockDriverState *bs,
+ VmdkExtent *extent,
+ uint64_t cluster_offset,
+ uint64_t offset,
+ bool allocate)
{
- BDRVVmdkState *s = bs->opaque;
- uint8_t whole_grain[s->cluster_sectors*512]; // 128 sectors * 512 bytes each = grain size 64KB
+ /* 128 sectors * 512 bytes each = grain size 64KB */
+ uint8_t whole_grain[extent->cluster_sectors * 512];
// we will be here if it's first write on non-exist grain(cluster).
// try to read from parent image, if exist
@@ -450,14 +523,14 @@ static int get_whole_cluster(BlockDriver
return -1;
ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
- s->cluster_sectors);
+ extent->cluster_sectors);
if (ret < 0) {
return -1;
}
//Write grain only into the active image
- ret = bdrv_write(bs->file, cluster_offset, whole_grain,
- s->cluster_sectors);
+ ret = bdrv_write(extent->file, cluster_offset, whole_grain,
+ extent->cluster_sectors);
if (ret < 0) {
return -1;
}
@@ -465,29 +538,39 @@ static int get_whole_cluster(BlockDriver
return 0;
}
-static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
+static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data)
{
- BDRVVmdkState *s = bs->opaque;
-
/* update L2 table */
- if (bdrv_pwrite_sync(bs->file, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
- &(m_data->offset), sizeof(m_data->offset)) < 0)
+ if (bdrv_pwrite_sync(
+ extent->file,
+ ((int64_t)m_data->l2_offset * 512)
+ + (m_data->l2_index * sizeof(m_data->offset)),
+ &(m_data->offset),
+ sizeof(m_data->offset)
+ ) < 0) {
return -1;
+ }
/* update backup L2 table */
- if (s->l1_backup_table_offset != 0) {
- m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
- if (bdrv_pwrite_sync(bs->file, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
- &(m_data->offset), sizeof(m_data->offset)) < 0)
+ if (extent->l1_backup_table_offset != 0) {
+ m_data->l2_offset = extent->l1_backup_table[m_data->l1_index];
+ if (bdrv_pwrite_sync(
+ extent->file,
+ ((int64_t)m_data->l2_offset * 512)
+ + (m_data->l2_index * sizeof(m_data->offset)),
+ &(m_data->offset), sizeof(m_data->offset)
+ ) < 0) {
return -1;
+ }
}
return 0;
}
-static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
- uint64_t offset, int allocate)
+static uint64_t get_cluster_offset(BlockDriverState *bs,
+ VmdkExtent *extent,
+ VmdkMetaData *m_data,
+ uint64_t offset, int allocate)
{
- BDRVVmdkState *s = bs->opaque;
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
uint32_t min_count, *l2_table, tmp = 0;
@@ -496,21 +579,23 @@ static uint64_t get_cluster_offset(Block
if (m_data)
m_data->valid = 0;
- l1_index = (offset >> 9) / s->l1_entry_sectors;
- if (l1_index >= s->l1_size)
+ l1_index = (offset >> 9) / extent->l1_entry_sectors;
+ if (l1_index >= extent->l1_size) {
return 0;
- l2_offset = s->l1_table[l1_index];
- if (!l2_offset)
+ }
+ l2_offset = extent->l1_table[l1_index];
+ if (!l2_offset) {
return 0;
+ }
for(i = 0; i < L2_CACHE_SIZE; i++) {
- if (l2_offset == s->l2_cache_offsets[i]) {
+ if (l2_offset == extent->l2_cache_offsets[i]) {
/* increment the hit count */
- if (++s->l2_cache_counts[i] == 0xffffffff) {
+ if (++extent->l2_cache_counts[i] == 0xffffffff) {
for(j = 0; j < L2_CACHE_SIZE; j++) {
- s->l2_cache_counts[j] >>= 1;
+ extent->l2_cache_counts[j] >>= 1;
}
}
- l2_table = s->l2_cache + (i * s->l2_size);
+ l2_table = extent->l2_cache + (i * extent->l2_size);
goto found;
}
}
@@ -518,20 +603,25 @@ static uint64_t get_cluster_offset(Block
min_index = 0;
min_count = 0xffffffff;
for(i = 0; i < L2_CACHE_SIZE; i++) {
- if (s->l2_cache_counts[i] < min_count) {
- min_count = s->l2_cache_counts[i];
+ if (extent->l2_cache_counts[i] < min_count) {
+ min_count = extent->l2_cache_counts[i];
min_index = i;
}
}
- l2_table = s->l2_cache + (min_index * s->l2_size);
- if (bdrv_pread(bs->file, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
- s->l2_size * sizeof(uint32_t))
+ l2_table = extent->l2_cache + (min_index * extent->l2_size);
+ if (bdrv_pread(
+ extent->file,
+ (int64_t)l2_offset * 512,
+ l2_table,
+ extent->l2_size * sizeof(uint32_t)
+ ) != extent->l2_size * sizeof(uint32_t)) {
return 0;
+ }
- s->l2_cache_offsets[min_index] = l2_offset;
- s->l2_cache_counts[min_index] = 1;
+ extent->l2_cache_offsets[min_index] = l2_offset;
+ extent->l2_cache_counts[min_index] = 1;
found:
- l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
+ l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
cluster_offset = le32_to_cpu(l2_table[l2_index]);
if (!cluster_offset) {
@@ -539,8 +629,11 @@ static uint64_t get_cluster_offset(Block
return 0;
// Avoid the L2 tables update for the images that have snapshots.
- cluster_offset = bdrv_getlength(bs->file);
- bdrv_truncate(bs->file, cluster_offset + (s->cluster_sectors << 9));
+ cluster_offset = bdrv_getlength(extent->file);
+ bdrv_truncate(
+ extent->file,
+ cluster_offset + (extent->cluster_sectors << 9)
+ );
cluster_offset >>= 9;
tmp = cpu_to_le32(cluster_offset);
@@ -551,7 +644,8 @@ static uint64_t get_cluster_offset(Block
* This problem may occur because of insufficient space on host disk
* or inappropriate VM shutdown.
*/
- if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
+ if (get_whole_cluster(
+ bs, extent, cluster_offset, offset, allocate) == -1)
return 0;
if (m_data) {
@@ -566,33 +660,69 @@ static uint64_t get_cluster_offset(Block
return cluster_offset;
}
+static VmdkExtent *find_extent(BDRVVmdkState *s,
+ int64_t sector_num, VmdkExtent *start_hint)
+{
+ VmdkExtent *extent = start_hint;
+
+ if (!extent) {
+ extent = &s->extents[0];
+ }
+ while (extent < &s->extents[s->num_extents]) {
+ if (sector_num < extent->end_sector) {
+ return extent;
+ }
+ extent++;
+ }
+ return NULL;
+}
+
static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVVmdkState *s = bs->opaque;
- int index_in_cluster, n;
- uint64_t cluster_offset;
- cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
- index_in_cluster = sector_num % s->cluster_sectors;
- n = s->cluster_sectors - index_in_cluster;
+ int64_t index_in_cluster, n, ret;
+ uint64_t offset;
+ VmdkExtent *extent;
+
+ extent = find_extent(s, sector_num, NULL);
+ if (!extent) {
+ return 0;
+ }
+ if (extent->flat) {
+ n = extent->end_sector - sector_num;
+ ret = 1;
+ } else {
+ offset = get_cluster_offset(bs, extent, NULL, sector_num * 512, 0);
+ index_in_cluster = sector_num % extent->cluster_sectors;
+ n = extent->cluster_sectors - index_in_cluster;
+ ret = offset ? 1 : 0;
+ }
if (n > nb_sectors)
n = nb_sectors;
*pnum = n;
- return (cluster_offset != 0);
+ return ret;
}
static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVVmdkState *s = bs->opaque;
- int index_in_cluster, n, ret;
+ int ret;
+ uint64_t n, index_in_cluster;
+ VmdkExtent *extent = NULL;
uint64_t cluster_offset;
while (nb_sectors > 0) {
- cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
- index_in_cluster = sector_num % s->cluster_sectors;
- n = s->cluster_sectors - index_in_cluster;
+ extent = find_extent(s, sector_num, extent);
+ if (!extent) {
+ return -EIO;
+ }
+ cluster_offset = get_cluster_offset(
+ bs, extent, NULL, sector_num << 9, 0);
+ index_in_cluster = sector_num % extent->cluster_sectors;
+ n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
if (!cluster_offset) {
@@ -621,10 +751,12 @@ static int vmdk_write(BlockDriverState *
const uint8_t *buf, int nb_sectors)
{
BDRVVmdkState *s = bs->opaque;
- VmdkMetaData m_data;
- int index_in_cluster, n;
+ VmdkExtent *extent = NULL;
+ int n;
+ int64_t index_in_cluster;
uint64_t cluster_offset;
static int cid_update = 0;
+ VmdkMetaData m_data;
if (sector_num > bs->total_sectors) {
fprintf(stderr,
@@ -635,20 +767,35 @@ static int vmdk_write(BlockDriverState *
}
while (nb_sectors > 0) {
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- n = s->cluster_sectors - index_in_cluster;
- if (n > nb_sectors)
- n = nb_sectors;
- cluster_offset = get_cluster_offset(bs, &m_data, sector_num << 9, 1);
- if (!cluster_offset)
+ extent = find_extent(s, sector_num, extent);
+ if (!extent) {
+ return -EIO;
+ }
+ cluster_offset = get_cluster_offset(
+ bs,
+ extent,
+ &m_data,
+ sector_num << 9, 1);
+ if (!cluster_offset) {
return -1;
+ }
+ index_in_cluster = sector_num % extent->cluster_sectors;
+ n = extent->cluster_sectors - index_in_cluster;
+ if (n > nb_sectors) {
+ n = nb_sectors;
+ }
- if (bdrv_pwrite(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
+ if (bdrv_pwrite(bs->file,
+ cluster_offset + index_in_cluster * 512,
+ buf, n * 512)
+ != n * 512) {
return -1;
+ }
if (m_data.valid) {
/* update L2 tables */
- if (vmdk_L2update(bs, &m_data) == -1)
+ if (vmdk_L2update(extent, &m_data) == -1) {
return -1;
+ }
}
nb_sectors -= n;
sector_num += n;
@@ -822,10 +969,7 @@ exit:
static void vmdk_close(BlockDriverState *bs)
{
- BDRVVmdkState *s = bs->opaque;
-
- qemu_free(s->l1_table);
- qemu_free(s->l2_cache);
+ vmdk_free_extents(bs);
}
static int vmdk_flush(BlockDriverState *bs)