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Diffstat (limited to 'block/vpc.c')
-rw-r--r--block/vpc.c102
1 files changed, 58 insertions, 44 deletions
diff --git a/block/vpc.c b/block/vpc.c
index 3713ec3a5f..3e2ea698d9 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -45,34 +45,34 @@ enum vhd_type {
VHD_DIFFERENCING = 4,
};
-// Seconds since Jan 1, 2000 0:00:00 (UTC)
+/* Seconds since Jan 1, 2000 0:00:00 (UTC) */
#define VHD_TIMESTAMP_BASE 946684800
#define VHD_CHS_MAX_C 65535LL
#define VHD_CHS_MAX_H 16
#define VHD_CHS_MAX_S 255
-#define VHD_MAX_SECTORS (65535LL * 255 * 255)
+#define VHD_MAX_SECTORS 0xff000000 /* 2040 GiB max image size */
#define VHD_MAX_GEOMETRY (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S)
#define VPC_OPT_FORCE_SIZE "force_size"
-// always big-endian
+/* always big-endian */
typedef struct vhd_footer {
- char creator[8]; // "conectix"
+ char creator[8]; /* "conectix" */
uint32_t features;
uint32_t version;
- // Offset of next header structure, 0xFFFFFFFF if none
+ /* Offset of next header structure, 0xFFFFFFFF if none */
uint64_t data_offset;
- // Seconds since Jan 1, 2000 0:00:00 (UTC)
+ /* Seconds since Jan 1, 2000 0:00:00 (UTC) */
uint32_t timestamp;
- char creator_app[4]; // "vpc "
+ char creator_app[4]; /* e.g., "vpc " */
uint16_t major;
uint16_t minor;
- char creator_os[4]; // "Wi2k"
+ char creator_os[4]; /* "Wi2k" */
uint64_t orig_size;
uint64_t current_size;
@@ -83,29 +83,29 @@ typedef struct vhd_footer {
uint32_t type;
- // Checksum of the Hard Disk Footer ("one's complement of the sum of all
- // the bytes in the footer without the checksum field")
+ /* Checksum of the Hard Disk Footer ("one's complement of the sum of all
+ the bytes in the footer without the checksum field") */
uint32_t checksum;
- // UUID used to identify a parent hard disk (backing file)
+ /* UUID used to identify a parent hard disk (backing file) */
uint8_t uuid[16];
uint8_t in_saved_state;
} QEMU_PACKED VHDFooter;
typedef struct vhd_dyndisk_header {
- char magic[8]; // "cxsparse"
+ char magic[8]; /* "cxsparse" */
- // Offset of next header structure, 0xFFFFFFFF if none
+ /* Offset of next header structure, 0xFFFFFFFF if none */
uint64_t data_offset;
- // Offset of the Block Allocation Table (BAT)
+ /* Offset of the Block Allocation Table (BAT) */
uint64_t table_offset;
uint32_t version;
- uint32_t max_table_entries; // 32bit/entry
+ uint32_t max_table_entries; /* 32bit/entry */
- // 2 MB by default, must be a power of two
+ /* 2 MB by default, must be a power of two */
uint32_t block_size;
uint32_t checksum;
@@ -113,7 +113,7 @@ typedef struct vhd_dyndisk_header {
uint32_t parent_timestamp;
uint32_t reserved;
- // Backing file name (in UTF-16)
+ /* Backing file name (in UTF-16) */
uint8_t parent_name[512];
struct {
@@ -238,6 +238,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
ret = bdrv_pread(bs->file->bs, 0, s->footer_buf, HEADER_SIZE);
if (ret < 0) {
+ error_setg(errp, "Unable to read VHD header");
goto fail;
}
@@ -246,9 +247,11 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
int64_t offset = bdrv_getlength(bs->file->bs);
if (offset < 0) {
ret = offset;
+ error_setg(errp, "Invalid file size");
goto fail;
} else if (offset < HEADER_SIZE) {
ret = -EINVAL;
+ error_setg(errp, "File too small for a VHD header");
goto fail;
}
@@ -275,9 +278,9 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
/* Write 'checksum' back to footer, or else will leave it with zero. */
footer->checksum = cpu_to_be32(checksum);
- // The visible size of a image in Virtual PC depends on the geometry
- // rather than on the size stored in the footer (the size in the footer
- // is too large usually)
+ /* The visible size of a image in Virtual PC depends on the geometry
+ rather than on the size stored in the footer (the size in the footer
+ is too large usually) */
bs->total_sectors = (int64_t)
be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
@@ -299,6 +302,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
* 'qem2' : current_size QEMU (uses current_size)
* 'win ' : current_size Hyper-V
* 'd2v ' : current_size Disk2vhd
+ * 'tap\0' : current_size XenServer
+ * 'CTXS' : current_size XenConverter
*
* The user can override the table values via drive options, however
* even with an override we will still use current_size for images
@@ -306,15 +311,17 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
*/
use_chs = (!!strncmp(footer->creator_app, "win ", 4) &&
!!strncmp(footer->creator_app, "qem2", 4) &&
- !!strncmp(footer->creator_app, "d2v ", 4)) || s->force_use_chs;
+ !!strncmp(footer->creator_app, "d2v ", 4) &&
+ !!strncmp(footer->creator_app, "CTXS", 4) &&
+ !!memcmp(footer->creator_app, "tap", 4)) || s->force_use_chs;
if (!use_chs || bs->total_sectors == VHD_MAX_GEOMETRY || s->force_use_sz) {
bs->total_sectors = be64_to_cpu(footer->current_size) /
BDRV_SECTOR_SIZE;
}
- /* Allow a maximum disk size of approximately 2 TB */
- if (bs->total_sectors >= VHD_MAX_SECTORS) {
+ /* Allow a maximum disk size of 2040 GiB */
+ if (bs->total_sectors > VHD_MAX_SECTORS) {
ret = -EFBIG;
goto fail;
}
@@ -323,12 +330,14 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
ret = bdrv_pread(bs->file->bs, be64_to_cpu(footer->data_offset), buf,
HEADER_SIZE);
if (ret < 0) {
+ error_setg(errp, "Error reading dynamic VHD header");
goto fail;
}
dyndisk_header = (VHDDynDiskHeader *) buf;
if (strncmp(dyndisk_header->magic, "cxsparse", 8)) {
+ error_setg(errp, "Invalid header magic");
ret = -EINVAL;
goto fail;
}
@@ -344,16 +353,14 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
if ((bs->total_sectors * 512) / s->block_size > 0xffffffffU) {
- ret = -EINVAL;
- goto fail;
- }
- if (s->max_table_entries > (VHD_MAX_SECTORS * 512) / s->block_size) {
+ error_setg(errp, "Too many blocks");
ret = -EINVAL;
goto fail;
}
computed_size = (uint64_t) s->max_table_entries * s->block_size;
if (computed_size < bs->total_sectors * 512) {
+ error_setg(errp, "Page table too small");
ret = -EINVAL;
goto fail;
}
@@ -370,6 +377,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
s->pagetable = qemu_try_blockalign(bs->file->bs, pagetable_size);
if (s->pagetable == NULL) {
+ error_setg(errp, "Unable to allocate memory for page table");
ret = -ENOMEM;
goto fail;
}
@@ -379,6 +387,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
ret = bdrv_pread(bs->file->bs, s->bat_offset, s->pagetable,
pagetable_size);
if (ret < 0) {
+ error_setg(errp, "Error reading pagetable");
goto fail;
}
@@ -457,16 +466,16 @@ static inline int64_t get_sector_offset(BlockDriverState *bs,
pageentry_index = (offset % s->block_size) / 512;
if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff)
- return -1; // not allocated
+ return -1; /* not allocated */
bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index];
block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index);
- // We must ensure that we don't write to any sectors which are marked as
- // unused in the bitmap. We get away with setting all bits in the block
- // bitmap each time we write to a new block. This might cause Virtual PC to
- // miss sparse read optimization, but it's not a problem in terms of
- // correctness.
+ /* We must ensure that we don't write to any sectors which are marked as
+ unused in the bitmap. We get away with setting all bits in the block
+ bitmap each time we write to a new block. This might cause Virtual PC to
+ miss sparse read optimization, but it's not a problem in terms of
+ correctness. */
if (write && (s->last_bitmap_offset != bitmap_offset)) {
uint8_t bitmap[s->bitmap_size];
@@ -512,18 +521,18 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
int ret;
uint8_t bitmap[s->bitmap_size];
- // Check if sector_num is valid
+ /* Check if sector_num is valid */
if ((sector_num < 0) || (sector_num > bs->total_sectors))
return -1;
- // Write entry into in-memory BAT
+ /* Write entry into in-memory BAT */
index = (sector_num * 512) / s->block_size;
if (s->pagetable[index] != 0xFFFFFFFF)
return -1;
s->pagetable[index] = s->free_data_block_offset / 512;
- // Initialize the block's bitmap
+ /* Initialize the block's bitmap */
memset(bitmap, 0xff, s->bitmap_size);
ret = bdrv_pwrite_sync(bs->file->bs, s->free_data_block_offset, bitmap,
s->bitmap_size);
@@ -531,13 +540,13 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
return ret;
}
- // Write new footer (the old one will be overwritten)
+ /* Write new footer (the old one will be overwritten) */
s->free_data_block_offset += s->block_size + s->bitmap_size;
ret = rewrite_footer(bs);
if (ret < 0)
goto fail;
- // Write BAT entry to disk
+ /* Write BAT entry to disk */
bat_offset = s->bat_offset + (4 * index);
bat_value = cpu_to_be32(s->pagetable[index]);
ret = bdrv_pwrite_sync(bs->file->bs, bat_offset, &bat_value, 4);
@@ -718,7 +727,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
* Note that the geometry doesn't always exactly match total_sectors but
* may round it down.
*
- * Returns 0 on success, -EFBIG if the size is larger than ~2 TB. Override
+ * Returns 0 on success, -EFBIG if the size is larger than 2040 GiB. Override
* the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)
* and instead allow up to 255 heads.
*/
@@ -770,7 +779,7 @@ static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
int ret;
int64_t offset = 0;
- // Write the footer (twice: at the beginning and at the end)
+ /* Write the footer (twice: at the beginning and at the end) */
block_size = 0x200000;
num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512);
@@ -785,7 +794,7 @@ static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
goto fail;
}
- // Write the initial BAT
+ /* Write the initial BAT */
offset = 3 * 512;
memset(buf, 0xFF, 512);
@@ -797,7 +806,7 @@ static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
offset += 512;
}
- // Prepare the Dynamic Disk Header
+ /* Prepare the Dynamic Disk Header */
memset(buf, 0, 1024);
memcpy(dyndisk_header->magic, "cxsparse", 8);
@@ -814,7 +823,7 @@ static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
dyndisk_header->checksum = cpu_to_be32(vpc_checksum(buf, 1024));
- // Write the header
+ /* Write the header */
offset = 512;
ret = blk_pwrite(blk, offset, buf, 1024);
@@ -874,6 +883,7 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
} else if (!strcmp(disk_type_param, "fixed")) {
disk_type = VHD_FIXED;
} else {
+ error_setg(errp, "Invalid disk type, %s", disk_type_param);
ret = -EINVAL;
goto out;
}
@@ -922,8 +932,9 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {
total_sectors = total_size / BDRV_SECTOR_SIZE;
- /* Allow a maximum disk size of approximately 2 TB */
+ /* Allow a maximum disk size of 2040 GiB */
if (total_sectors > VHD_MAX_SECTORS) {
+ error_setg(errp, "Disk size is too large, max size is 2040 GiB");
ret = -EFBIG;
goto out;
}
@@ -974,6 +985,9 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
} else {
ret = create_fixed_disk(blk, buf, total_size);
}
+ if (ret < 0) {
+ error_setg(errp, "Unable to create or write VHD header");
+ }
out:
blk_unref(blk);
generated by cgit v1.2.3 (git 2.26.2) at 2025-03-05 10:40:45 +0000