* [Qemu-devel] [PATCH v3 3/3] vmdk: Add read-only support for seSparse snapshots
2019-06-20 9:10 [Qemu-devel] [PATCH v3 0/3] vmdk: Add read-only support for the new seSparse format Sam Eiderman
2019-06-20 9:10 ` [Qemu-devel] [PATCH v3 1/3] vmdk: Fix comment regarding max l1_size coverage Sam Eiderman
2019-06-20 9:10 ` [Qemu-devel] [PATCH v3 2/3] vmdk: Reduce the max bound for L1 table size Sam Eiderman
@ 2019-06-20 9:10 ` Sam Eiderman
2019-06-20 13:44 ` [Qemu-devel] [PATCH v3 0/3] vmdk: Add read-only support for the new seSparse format Max Reitz
3 siblings, 0 replies; 5+ messages in thread
From: Sam Eiderman @ 2019-06-20 9:10 UTC (permalink / raw)
To: kwolf, qemu-block, qemu-devel, mreitz
Cc: liran.alon, shmuel.eiderman, karl.heubaum, arbel.moshe
Until ESXi 6.5 VMware used the vmfsSparse format for snapshots (VMDK3 in
QEMU).
This format was lacking in the following:
* Grain directory (L1) and grain table (L2) entries were 32-bit,
allowing access to only 2TB (slightly less) of data.
* The grain size (default) was 512 bytes - leading to data
fragmentation and many grain tables.
* For space reclamation purposes, it was necessary to find all the
grains which are not pointed to by any grain table - so a reverse
mapping of "offset of grain in vmdk" to "grain table" must be
constructed - which takes large amounts of CPU/RAM.
The format specification can be found in VMware's documentation:
https://www.vmware.com/support/developer/vddk/vmdk_50_technote.pdf
In ESXi 6.5, to support snapshot files larger than 2TB, a new format was
introduced: SESparse (Space Efficient).
This format fixes the above issues:
* All entries are now 64-bit.
* The grain size (default) is 4KB.
* Grain directory and grain tables are now located at the beginning
of the file.
+ seSparse format reserves space for all grain tables.
+ Grain tables can be addressed using an index.
+ Grains are located in the end of the file and can also be
addressed with an index.
- seSparse vmdks of large disks (64TB) have huge preallocated
headers - mainly due to L2 tables, even for empty snapshots.
* The header contains a reverse mapping ("backmap") of "offset of
grain in vmdk" to "grain table" and a bitmap ("free bitmap") which
specifies for each grain - whether it is allocated or not.
Using these data structures we can implement space reclamation
efficiently.
* Due to the fact that the header now maintains two mappings:
* The regular one (grain directory & grain tables)
* A reverse one (backmap and free bitmap)
These data structures can lose consistency upon crash and result
in a corrupted VMDK.
Therefore, a journal is also added to the VMDK and is replayed
when the VMware reopens the file after a crash.
Since ESXi 6.7 - SESparse is the only snapshot format available.
Unfortunately, VMware does not provide documentation regarding the new
seSparse format.
This commit is based on black-box research of the seSparse format.
Various in-guest block operations and their effect on the snapshot file
were tested.
The only VMware provided source of information (regarding the underlying
implementation) was a log file on the ESXi:
/var/log/hostd.log
Whenever an seSparse snapshot is created - the log is being populated
with seSparse records.
Relevant log records are of the form:
[...] Const Header:
[...] constMagic = 0xcafebabe
[...] version = 2.1
[...] capacity = 204800
[...] grainSize = 8
[...] grainTableSize = 64
[...] flags = 0
[...] Extents:
[...] Header : <1 : 1>
[...] JournalHdr : <2 : 2>
[...] Journal : <2048 : 2048>
[...] GrainDirectory : <4096 : 2048>
[...] GrainTables : <6144 : 2048>
[...] FreeBitmap : <8192 : 2048>
[...] BackMap : <10240 : 2048>
[...] Grain : <12288 : 204800>
[...] Volatile Header:
[...] volatileMagic = 0xcafecafe
[...] FreeGTNumber = 0
[...] nextTxnSeqNumber = 0
[...] replayJournal = 0
The sizes that are seen in the log file are in sectors.
Extents are of the following format: <offset : size>
This commit is a strict implementation which enforces:
* magics
* version number 2.1
* grain size of 8 sectors (4KB)
* grain table size of 64 sectors
* zero flags
* extent locations
Additionally, this commit proivdes only a subset of the functionality
offered by seSparse's format:
* Read-only
* No journal replay
* No space reclamation
* No unmap support
Hence, journal header, journal, free bitmap and backmap extents are
unused, only the "classic" (L1 -> L2 -> data) grain access is
implemented.
However there are several differences in the grain access itself.
Grain directory (L1):
* Grain directory entries are indexes (not offsets) to grain
tables.
* Valid grain directory entries have their highest nibble set to
0x1.
* Since grain tables are always located in the beginning of the
file - the index can fit into 32 bits - so we can use its low
part if it's valid.
Grain table (L2):
* Grain table entries are indexes (not offsets) to grains.
* If the highest nibble of the entry is:
0x0:
The grain in not allocated.
The rest of the bytes are 0.
0x1:
The grain is unmapped - guest sees a zero grain.
The rest of the bits point to the previously mapped grain,
see 0x3 case.
0x2:
The grain is zero.
0x3:
The grain is allocated - to get the index calculate:
((entry & 0x0fff000000000000) >> 48) |
((entry & 0x0000ffffffffffff) << 12)
* The difference between 0x1 and 0x2 is that 0x1 is an unallocated
grain which results from the guest using sg_unmap to unmap the
grain - but the grain itself still exists in the grain extent - a
space reclamation procedure should delete it.
Unmapping a zero grain has no effect (0x2 will not change to 0x1)
but unmapping an unallocated grain will (0x0 to 0x1) - naturally.
In order to implement seSparse some fields had to be changed to support
both 32-bit and 64-bit entry sizes.
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Reviewed-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com>
---
block/vmdk.c | 358 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 342 insertions(+), 16 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index 931eb2759c..bd36ece125 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -91,6 +91,44 @@ typedef struct {
uint16_t compressAlgorithm;
} QEMU_PACKED VMDK4Header;
+typedef struct VMDKSESparseConstHeader {
+ uint64_t magic;
+ uint64_t version;
+ uint64_t capacity;
+ uint64_t grain_size;
+ uint64_t grain_table_size;
+ uint64_t flags;
+ uint64_t reserved1;
+ uint64_t reserved2;
+ uint64_t reserved3;
+ uint64_t reserved4;
+ uint64_t volatile_header_offset;
+ uint64_t volatile_header_size;
+ uint64_t journal_header_offset;
+ uint64_t journal_header_size;
+ uint64_t journal_offset;
+ uint64_t journal_size;
+ uint64_t grain_dir_offset;
+ uint64_t grain_dir_size;
+ uint64_t grain_tables_offset;
+ uint64_t grain_tables_size;
+ uint64_t free_bitmap_offset;
+ uint64_t free_bitmap_size;
+ uint64_t backmap_offset;
+ uint64_t backmap_size;
+ uint64_t grains_offset;
+ uint64_t grains_size;
+ uint8_t pad[304];
+} QEMU_PACKED VMDKSESparseConstHeader;
+
+typedef struct VMDKSESparseVolatileHeader {
+ uint64_t magic;
+ uint64_t free_gt_number;
+ uint64_t next_txn_seq_number;
+ uint64_t replay_journal;
+ uint8_t pad[480];
+} QEMU_PACKED VMDKSESparseVolatileHeader;
+
#define L2_CACHE_SIZE 16
typedef struct VmdkExtent {
@@ -99,19 +137,23 @@ typedef struct VmdkExtent {
bool compressed;
bool has_marker;
bool has_zero_grain;
+ bool sesparse;
+ uint64_t sesparse_l2_tables_offset;
+ uint64_t sesparse_clusters_offset;
+ int32_t entry_size;
int version;
int64_t sectors;
int64_t end_sector;
int64_t flat_start_offset;
int64_t l1_table_offset;
int64_t l1_backup_table_offset;
- uint32_t *l1_table;
+ void *l1_table;
uint32_t *l1_backup_table;
unsigned int l1_size;
uint32_t l1_entry_sectors;
unsigned int l2_size;
- uint32_t *l2_cache;
+ void *l2_cache;
uint32_t l2_cache_offsets[L2_CACHE_SIZE];
uint32_t l2_cache_counts[L2_CACHE_SIZE];
@@ -435,6 +477,11 @@ static int vmdk_add_extent(BlockDriverState *bs,
* minimal L2 table size: 512 entries
* 8 TB is still more than the maximal value supported for
* VMDK3 & VMDK4 which is 2TB.
+ * 64TB - for "ESXi seSparse Extent"
+ * minimal cluster size: 512B (default is 4KB)
+ * L2 table size: 4096 entries (const).
+ * 64TB is more than the maximal value supported for
+ * seSparse VMDKs (which is slightly less than 64TB)
*/
error_setg(errp, "L1 size too big");
return -EFBIG;
@@ -460,6 +507,7 @@ static int vmdk_add_extent(BlockDriverState *bs,
extent->l2_size = l2_size;
extent->cluster_sectors = flat ? sectors : cluster_sectors;
extent->next_cluster_sector = ROUND_UP(nb_sectors, cluster_sectors);
+ extent->entry_size = sizeof(uint32_t);
if (s->num_extents > 1) {
extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
@@ -481,7 +529,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
int i;
/* read the L1 table */
- l1_size = extent->l1_size * sizeof(uint32_t);
+ l1_size = extent->l1_size * extent->entry_size;
extent->l1_table = g_try_malloc(l1_size);
if (l1_size && extent->l1_table == NULL) {
return -ENOMEM;
@@ -499,10 +547,16 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
goto fail_l1;
}
for (i = 0; i < extent->l1_size; i++) {
- le32_to_cpus(&extent->l1_table[i]);
+ if (extent->entry_size == sizeof(uint64_t)) {
+ le64_to_cpus((uint64_t *)extent->l1_table + i);
+ } else {
+ assert(extent->entry_size == sizeof(uint32_t));
+ le32_to_cpus((uint32_t *)extent->l1_table + i);
+ }
}
if (extent->l1_backup_table_offset) {
+ assert(!extent->sesparse);
extent->l1_backup_table = g_try_malloc(l1_size);
if (l1_size && extent->l1_backup_table == NULL) {
ret = -ENOMEM;
@@ -525,7 +579,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
}
extent->l2_cache =
- g_new(uint32_t, extent->l2_size * L2_CACHE_SIZE);
+ g_malloc(extent->entry_size * extent->l2_size * L2_CACHE_SIZE);
return 0;
fail_l1b:
g_free(extent->l1_backup_table);
@@ -571,6 +625,205 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
return ret;
}
+#define SESPARSE_CONST_HEADER_MAGIC UINT64_C(0x00000000cafebabe)
+#define SESPARSE_VOLATILE_HEADER_MAGIC UINT64_C(0x00000000cafecafe)
+
+/* Strict checks - format not officially documented */
+static int check_se_sparse_const_header(VMDKSESparseConstHeader *header,
+ Error **errp)
+{
+ header->magic = le64_to_cpu(header->magic);
+ header->version = le64_to_cpu(header->version);
+ header->grain_size = le64_to_cpu(header->grain_size);
+ header->grain_table_size = le64_to_cpu(header->grain_table_size);
+ header->flags = le64_to_cpu(header->flags);
+ header->reserved1 = le64_to_cpu(header->reserved1);
+ header->reserved2 = le64_to_cpu(header->reserved2);
+ header->reserved3 = le64_to_cpu(header->reserved3);
+ header->reserved4 = le64_to_cpu(header->reserved4);
+
+ header->volatile_header_offset =
+ le64_to_cpu(header->volatile_header_offset);
+ header->volatile_header_size = le64_to_cpu(header->volatile_header_size);
+
+ header->journal_header_offset = le64_to_cpu(header->journal_header_offset);
+ header->journal_header_size = le64_to_cpu(header->journal_header_size);
+
+ header->journal_offset = le64_to_cpu(header->journal_offset);
+ header->journal_size = le64_to_cpu(header->journal_size);
+
+ header->grain_dir_offset = le64_to_cpu(header->grain_dir_offset);
+ header->grain_dir_size = le64_to_cpu(header->grain_dir_size);
+
+ header->grain_tables_offset = le64_to_cpu(header->grain_tables_offset);
+ header->grain_tables_size = le64_to_cpu(header->grain_tables_size);
+
+ header->free_bitmap_offset = le64_to_cpu(header->free_bitmap_offset);
+ header->free_bitmap_size = le64_to_cpu(header->free_bitmap_size);
+
+ header->backmap_offset = le64_to_cpu(header->backmap_offset);
+ header->backmap_size = le64_to_cpu(header->backmap_size);
+
+ header->grains_offset = le64_to_cpu(header->grains_offset);
+ header->grains_size = le64_to_cpu(header->grains_size);
+
+ if (header->magic != SESPARSE_CONST_HEADER_MAGIC) {
+ error_setg(errp, "Bad const header magic: 0x%016" PRIx64,
+ header->magic);
+ return -EINVAL;
+ }
+
+ if (header->version != 0x0000000200000001) {
+ error_setg(errp, "Unsupported version: 0x%016" PRIx64,
+ header->version);
+ return -ENOTSUP;
+ }
+
+ if (header->grain_size != 8) {
+ error_setg(errp, "Unsupported grain size: %" PRIu64,
+ header->grain_size);
+ return -ENOTSUP;
+ }
+
+ if (header->grain_table_size != 64) {
+ error_setg(errp, "Unsupported grain table size: %" PRIu64,
+ header->grain_table_size);
+ return -ENOTSUP;
+ }
+
+ if (header->flags != 0) {
+ error_setg(errp, "Unsupported flags: 0x%016" PRIx64,
+ header->flags);
+ return -ENOTSUP;
+ }
+
+ if (header->reserved1 != 0 || header->reserved2 != 0 ||
+ header->reserved3 != 0 || header->reserved4 != 0) {
+ error_setg(errp, "Unsupported reserved bits:"
+ " 0x%016" PRIx64 " 0x%016" PRIx64
+ " 0x%016" PRIx64 " 0x%016" PRIx64,
+ header->reserved1, header->reserved2,
+ header->reserved3, header->reserved4);
+ return -ENOTSUP;
+ }
+
+ /* check that padding is 0 */
+ if (!buffer_is_zero(header->pad, sizeof(header->pad))) {
+ error_setg(errp, "Unsupported non-zero const header padding");
+ return -ENOTSUP;
+ }
+
+ return 0;
+}
+
+static int check_se_sparse_volatile_header(VMDKSESparseVolatileHeader *header,
+ Error **errp)
+{
+ header->magic = le64_to_cpu(header->magic);
+ header->free_gt_number = le64_to_cpu(header->free_gt_number);
+ header->next_txn_seq_number = le64_to_cpu(header->next_txn_seq_number);
+ header->replay_journal = le64_to_cpu(header->replay_journal);
+
+ if (header->magic != SESPARSE_VOLATILE_HEADER_MAGIC) {
+ error_setg(errp, "Bad volatile header magic: 0x%016" PRIx64,
+ header->magic);
+ return -EINVAL;
+ }
+
+ if (header->replay_journal) {
+ error_setg(errp, "Image is dirty, Replaying journal not supported");
+ return -ENOTSUP;
+ }
+
+ /* check that padding is 0 */
+ if (!buffer_is_zero(header->pad, sizeof(header->pad))) {
+ error_setg(errp, "Unsupported non-zero volatile header padding");
+ return -ENOTSUP;
+ }
+
+ return 0;
+}
+
+static int vmdk_open_se_sparse(BlockDriverState *bs,
+ BdrvChild *file,
+ int flags, Error **errp)
+{
+ int ret;
+ VMDKSESparseConstHeader const_header;
+ VMDKSESparseVolatileHeader volatile_header;
+ VmdkExtent *extent;
+
+ ret = bdrv_apply_auto_read_only(bs,
+ "No write support for seSparse images available", errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ assert(sizeof(const_header) == SECTOR_SIZE);
+
+ ret = bdrv_pread(file, 0, &const_header, sizeof(const_header));
+ if (ret < 0) {
+ bdrv_refresh_filename(file->bs);
+ error_setg_errno(errp, -ret,
+ "Could not read const header from file '%s'",
+ file->bs->filename);
+ return ret;
+ }
+
+ /* check const header */
+ ret = check_se_sparse_const_header(&const_header, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ assert(sizeof(volatile_header) == SECTOR_SIZE);
+
+ ret = bdrv_pread(file,
+ const_header.volatile_header_offset * SECTOR_SIZE,
+ &volatile_header, sizeof(volatile_header));
+ if (ret < 0) {
+ bdrv_refresh_filename(file->bs);
+ error_setg_errno(errp, -ret,
+ "Could not read volatile header from file '%s'",
+ file->bs->filename);
+ return ret;
+ }
+
+ /* check volatile header */
+ ret = check_se_sparse_volatile_header(&volatile_header, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = vmdk_add_extent(bs, file, false,
+ const_header.capacity,
+ const_header.grain_dir_offset * SECTOR_SIZE,
+ 0,
+ const_header.grain_dir_size *
+ SECTOR_SIZE / sizeof(uint64_t),
+ const_header.grain_table_size *
+ SECTOR_SIZE / sizeof(uint64_t),
+ const_header.grain_size,
+ &extent,
+ errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ extent->sesparse = true;
+ extent->sesparse_l2_tables_offset = const_header.grain_tables_offset;
+ extent->sesparse_clusters_offset = const_header.grains_offset;
+ extent->entry_size = sizeof(uint64_t);
+
+ ret = vmdk_init_tables(bs, extent, errp);
+ if (ret) {
+ /* free extent allocated by vmdk_add_extent */
+ vmdk_free_last_extent(bs);
+ }
+
+ return ret;
+}
+
static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
QDict *options, Error **errp);
@@ -848,6 +1101,7 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
* RW [size in sectors] SPARSE "file-name.vmdk"
* RW [size in sectors] VMFS "file-name.vmdk"
* RW [size in sectors] VMFSSPARSE "file-name.vmdk"
+ * RW [size in sectors] SESPARSE "file-name.vmdk"
*/
flat_offset = -1;
matches = sscanf(p, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" SCNd64,
@@ -870,7 +1124,8 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
if (sectors <= 0 ||
(strcmp(type, "FLAT") && strcmp(type, "SPARSE") &&
- strcmp(type, "VMFS") && strcmp(type, "VMFSSPARSE")) ||
+ strcmp(type, "VMFS") && strcmp(type, "VMFSSPARSE") &&
+ strcmp(type, "SESPARSE")) ||
(strcmp(access, "RW"))) {
continue;
}
@@ -923,6 +1178,13 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
return ret;
}
extent = &s->extents[s->num_extents - 1];
+ } else if (!strcmp(type, "SESPARSE")) {
+ ret = vmdk_open_se_sparse(bs, extent_file, bs->open_flags, errp);
+ if (ret) {
+ bdrv_unref_child(bs, extent_file);
+ return ret;
+ }
+ extent = &s->extents[s->num_extents - 1];
} else {
error_setg(errp, "Unsupported extent type '%s'", type);
bdrv_unref_child(bs, extent_file);
@@ -957,6 +1219,7 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
if (strcmp(ct, "monolithicFlat") &&
strcmp(ct, "vmfs") &&
strcmp(ct, "vmfsSparse") &&
+ strcmp(ct, "seSparse") &&
strcmp(ct, "twoGbMaxExtentSparse") &&
strcmp(ct, "twoGbMaxExtentFlat")) {
error_setg(errp, "Unsupported image type '%s'", ct);
@@ -1207,10 +1470,12 @@ static int get_cluster_offset(BlockDriverState *bs,
{
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
- uint32_t min_count, *l2_table;
+ uint32_t min_count;
+ void *l2_table;
bool zeroed = false;
int64_t ret;
int64_t cluster_sector;
+ unsigned int l2_size_bytes = extent->l2_size * extent->entry_size;
if (m_data) {
m_data->valid = 0;
@@ -1225,7 +1490,36 @@ static int get_cluster_offset(BlockDriverState *bs,
if (l1_index >= extent->l1_size) {
return VMDK_ERROR;
}
- l2_offset = extent->l1_table[l1_index];
+ if (extent->sesparse) {
+ uint64_t l2_offset_u64;
+
+ assert(extent->entry_size == sizeof(uint64_t));
+
+ l2_offset_u64 = ((uint64_t *)extent->l1_table)[l1_index];
+ if (l2_offset_u64 == 0) {
+ l2_offset = 0;
+ } else if ((l2_offset_u64 & 0xffffffff00000000) != 0x1000000000000000) {
+ /*
+ * Top most nibble is 0x1 if grain table is allocated.
+ * strict check - top most 4 bytes must be 0x10000000 since max
+ * supported size is 64TB for disk - so no more than 64TB / 16MB
+ * grain directories which is smaller than uint32,
+ * where 16MB is the only supported default grain table coverage.
+ */
+ return VMDK_ERROR;
+ } else {
+ l2_offset_u64 = l2_offset_u64 & 0x00000000ffffffff;
+ l2_offset_u64 = extent->sesparse_l2_tables_offset +
+ l2_offset_u64 * l2_size_bytes / SECTOR_SIZE;
+ if (l2_offset_u64 > 0x00000000ffffffff) {
+ return VMDK_ERROR;
+ }
+ l2_offset = (unsigned int)(l2_offset_u64);
+ }
+ } else {
+ assert(extent->entry_size == sizeof(uint32_t));
+ l2_offset = ((uint32_t *)extent->l1_table)[l1_index];
+ }
if (!l2_offset) {
return VMDK_UNALLOC;
}
@@ -1237,7 +1531,7 @@ static int get_cluster_offset(BlockDriverState *bs,
extent->l2_cache_counts[j] >>= 1;
}
}
- l2_table = extent->l2_cache + (i * extent->l2_size);
+ l2_table = (char *)extent->l2_cache + (i * l2_size_bytes);
goto found;
}
}
@@ -1250,13 +1544,13 @@ static int get_cluster_offset(BlockDriverState *bs,
min_index = i;
}
}
- l2_table = extent->l2_cache + (min_index * extent->l2_size);
+ l2_table = (char *)extent->l2_cache + (min_index * l2_size_bytes);
BLKDBG_EVENT(extent->file, BLKDBG_L2_LOAD);
if (bdrv_pread(extent->file,
(int64_t)l2_offset * 512,
l2_table,
- extent->l2_size * sizeof(uint32_t)
- ) != extent->l2_size * sizeof(uint32_t)) {
+ l2_size_bytes
+ ) != l2_size_bytes) {
return VMDK_ERROR;
}
@@ -1264,16 +1558,45 @@ static int get_cluster_offset(BlockDriverState *bs,
extent->l2_cache_counts[min_index] = 1;
found:
l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
- cluster_sector = le32_to_cpu(l2_table[l2_index]);
- if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) {
- zeroed = true;
+ if (extent->sesparse) {
+ cluster_sector = le64_to_cpu(((uint64_t *)l2_table)[l2_index]);
+ switch (cluster_sector & 0xf000000000000000) {
+ case 0x0000000000000000:
+ /* unallocated grain */
+ if (cluster_sector != 0) {
+ return VMDK_ERROR;
+ }
+ break;
+ case 0x1000000000000000:
+ /* scsi-unmapped grain - fallthrough */
+ case 0x2000000000000000:
+ /* zero grain */
+ zeroed = true;
+ break;
+ case 0x3000000000000000:
+ /* allocated grain */
+ cluster_sector = (((cluster_sector & 0x0fff000000000000) >> 48) |
+ ((cluster_sector & 0x0000ffffffffffff) << 12));
+ cluster_sector = extent->sesparse_clusters_offset +
+ cluster_sector * extent->cluster_sectors;
+ break;
+ default:
+ return VMDK_ERROR;
+ }
+ } else {
+ cluster_sector = le32_to_cpu(((uint32_t *)l2_table)[l2_index]);
+
+ if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) {
+ zeroed = true;
+ }
}
if (!cluster_sector || zeroed) {
if (!allocate) {
return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
}
+ assert(!extent->sesparse);
if (extent->next_cluster_sector >= VMDK_EXTENT_MAX_SECTORS) {
return VMDK_ERROR;
@@ -1297,7 +1620,7 @@ static int get_cluster_offset(BlockDriverState *bs,
m_data->l1_index = l1_index;
m_data->l2_index = l2_index;
m_data->l2_offset = l2_offset;
- m_data->l2_cache_entry = &l2_table[l2_index];
+ m_data->l2_cache_entry = ((uint32_t *)l2_table) + l2_index;
}
}
*cluster_offset = cluster_sector << BDRV_SECTOR_BITS;
@@ -1623,6 +1946,9 @@ static int vmdk_pwritev(BlockDriverState *bs, uint64_t offset,
if (!extent) {
return -EIO;
}
+ if (extent->sesparse) {
+ return -ENOTSUP;
+ }
offset_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
n_bytes = MIN(bytes, extent->cluster_sectors * BDRV_SECTOR_SIZE
- offset_in_cluster);
--
2.13.3
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