| Message ID | 1411738998-3019-1-git-send-email-gordongong0350@gmail.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Sep 26, 2014 at 09:43:18PM +0800, Xiaodong Gong wrote: > Now qemu only supports vhd type VHD_FIXED and VHD_DYNAMIC, so qemu > can't read snapshot volume of vhd, and can't support other storage > features of vhd file. > > This patch add read parent information in function "vpc_open", read > bitmap in "vpc_read", and change bitmap in "vpc_write". > > Signed-off-by: Xiaodong Gong <gordongong0350@gmail.com> > --- > block/vpc.c | 428 ++++++++++++++++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 357 insertions(+), 71 deletions(-) Waiting for code review. I only consider patches for the block branch that have at least 1 Reviewed-by from another contributor. Anyone? > diff --git a/block/vpc.c b/block/vpc.c > index 4947369..1210542 100644 > --- a/block/vpc.c > +++ b/block/vpc.c > @@ -29,17 +29,27 @@ > #if defined(CONFIG_UUID) > #include <uuid/uuid.h> > #endif > +#include <iconv.h> > > /**************************************************************/ > > #define HEADER_SIZE 512 > +#define DYNAMIC_HEADER_SIZE 1024 > +#define PARENT_LOCATOR_NUM 8 > +#define MACX_PREFIX_LEN 7 /* file:// */ > +#define TBBATMAP_HEAD_SIZE 28 > + > +#define PLATFORM_MACX 0x5863614d /* big endian */ > +#define PLATFORM_W2RU 0x75723257 > + > +#define VHD_VERSION(major, minor) (((major) << 16) | ((minor) & 0x0000FFFF)) > > //#define CACHE > > enum vhd_type { > VHD_FIXED = 2, > VHD_DYNAMIC = 3, > - VHD_DIFFERENCING = 4, > + VHD_DIFF = 4, > }; > > // Seconds since Jan 1, 2000 0:00:00 (UTC) > @@ -138,6 +148,15 @@ typedef struct BDRVVPCState { > Error *migration_blocker; > } BDRVVPCState; > > +typedef struct vhd_tdbatmap_header { > + char magic[8]; /* always "tdbatmap" */ > + > + uint64_t batmap_offset; > + uint32_t batmap_size; > + uint32_t batmap_version; > + uint32_t checksum; > +} QEMU_PACKED VHDTdBatmapHeader; > + > static uint32_t vpc_checksum(uint8_t* buf, size_t size) > { > uint32_t res = 0; > @@ -153,10 +172,107 @@ static uint32_t vpc_checksum(uint8_t* buf, size_t size) > static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) > { > if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) > - return 100; > + return 100; > return 0; > } > > +static int vpc_read_backing_loc(VHDDynDiskHeader *dyndisk_header, > + BlockDriverState *bs, > + Error **errp) > +{ > + BDRVVPCState *s = bs->opaque; > + int64_t data_offset = 0; > + int data_length = 0; > + uint32_t platform; > + bool done = false; > + int parent_locator_offset = 0; > + int i; > + int ret = 0; > + > + for (i = 0; i < PARENT_LOCATOR_NUM; i++) { > + data_offset = > + be64_to_cpu(dyndisk_header->parent_locator[i].data_offset); > + data_length = > + be32_to_cpu(dyndisk_header->parent_locator[i].data_length); > + platform = dyndisk_header->parent_locator[i].platform; > + > + /* Extend the location offset */ > + if (parent_locator_offset < data_offset) { > + parent_locator_offset = data_offset; > + } > + > + if (done) { > + continue; > + } > + > + /* Skip "file://" in MacX platform */ > + if (platform == PLATFORM_MACX) { > + data_offset += MACX_PREFIX_LEN; > + data_length -= MACX_PREFIX_LEN; > + } > + > + /* Read location of backing file */ > + if (platform == PLATFORM_MACX || platform == PLATFORM_W2RU) { > + if (data_offset > s->max_table_entries * s->block_size) { > + return -1; > + } > + if (data_length > BDRV_SECTOR_SIZE) { > + return -1; > + } > + ret = bdrv_pread(bs->file, data_offset, bs->backing_file, > + data_length); > + if (ret < 0) { > + return ret; > + } > + bs->backing_file[data_length] = '\0'; > + } > + > + /* Convert location to ACSII string */ > + if (platform == PLATFORM_MACX) { > + done = true; > + > + } else if (platform == PLATFORM_W2RU) { > + /* Must be UTF16-LE to ASCII */ > + char *out, *optr; > + int j; > + > + optr = out = (char *) malloc(data_length + 1); > + if (out == NULL) { > + ret = -1; > + return ret; > + } > + memset(out, 0, data_length + 1); > + > + for (j = 0; j < data_length + 1; j++) { > + out[j] = bs->backing_file[2*j]; > + } > + out[data_length + 1] = '\0'; > + > + while (*optr != '\0') { > + if (*optr == '\\') { > + *optr = '/'; > + } > + optr++; > + } > + > + strncpy(bs->backing_file, out, data_length + 1); > + > + out = NULL; > + free(out); > + > + done = true; > + } > + } > + > + if (bs->backing_file[0] == '\0') { > + error_setg(errp, "block-vpc: differencing is not support in w2ku"); > + ret = -EINVAL; > + return ret; > + } > + > + return parent_locator_offset; > +} > + > static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > Error **errp) > { > @@ -164,11 +280,14 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > int i; > VHDFooter *footer; > VHDDynDiskHeader *dyndisk_header; > - uint8_t buf[HEADER_SIZE]; > + uint8_t buf[DYNAMIC_HEADER_SIZE]; > + uint8_t tdbatmap_header_buf[TBBATMAP_HEAD_SIZE]; > uint32_t checksum; > uint64_t computed_size; > - int disk_type = VHD_DYNAMIC; > + uint32_t disk_type; > int ret; > + VHDTdBatmapHeader *tdbatmap_header; > + int parent_locator_offset = 0; > > ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); > if (ret < 0) { > @@ -176,6 +295,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > } > > footer = (VHDFooter *) s->footer_buf; > + disk_type = be32_to_cpu(footer->type); > + > if (strncmp(footer->creator, "conectix", 8)) { > int64_t offset = bdrv_getlength(bs->file); > if (offset < 0) { > @@ -230,9 +351,9 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > goto fail; > } > > - if (disk_type == VHD_DYNAMIC) { > + if (disk_type == VHD_DYNAMIC || disk_type == VHD_DIFF) { > ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, > - HEADER_SIZE); > + DYNAMIC_HEADER_SIZE); > if (ret < 0) { > goto fail; > } > @@ -286,6 +407,37 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > s->free_data_block_offset = > (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; > > + /* Read tdbatmap header by offset */ > + if (footer->version >= VHD_VERSION(1, 2)) { > + ret = bdrv_pread(bs->file, s->free_data_block_offset, > + tdbatmap_header_buf, TBBATMAP_HEAD_SIZE); > + if (ret < 0) { > + goto fail; > + } > + > + tdbatmap_header = (VHDTdBatmapHeader *) tdbatmap_header_buf; > + if (!strncmp(tdbatmap_header->magic, "tdbatmap", 8)) { > + s->free_data_block_offset = > + be32_to_cpu(tdbatmap_header->batmap_size) * 512 > + + be64_to_cpu(tdbatmap_header->batmap_offset); > + } > + } > + > + /* Read backing file location from dyn header table */ > + if (dyndisk_header->parent_name[0] || dyndisk_header->parent_name[1]) { > + ret = parent_locator_offset = vpc_read_backing_loc(dyndisk_header, > + bs, errp); > + if (ret < 0) { > + goto fail; > + } > + } > + > + if (s->free_data_block_offset < parent_locator_offset > + + BDRV_SECTOR_SIZE) { > + s->free_data_block_offset = parent_locator_offset > + + BDRV_SECTOR_SIZE; > + } > + > for (i = 0; i < s->max_table_entries; i++) { > be32_to_cpus(&s->pagetable[i]); > if (s->pagetable[i] != 0xFFFFFFFF) { > @@ -340,35 +492,76 @@ static int vpc_reopen_prepare(BDRVReopenState *state, > } > > /* > - * Returns the absolute byte offset of the given sector in the image file. > - * If the sector is not allocated, -1 is returned instead. > + * Returns the absolute byte offset of the given sector in the differencing > + * image file. > + * > + * If error happened, -1 is returned. > + * > + * When write all type or read dynamic, if the sector is not allocated, -2 > + * is returned instead. If the sector is allocated in current file, the block > + * offset is returned. > * > - * The parameter write must be 1 if the offset will be used for a write > - * operation (the block bitmaps is updated then), 0 otherwise. > + * When read diff. If the sector is not allocated, -2 is returned instead. > + * If the sector is allocated in the backing file, -3 is returned. If the > + * sector is allocated in current file, the block offset is returned. > */ > static inline int64_t get_sector_offset(BlockDriverState *bs, > - int64_t sector_num, int write) > + int64_t sector_num, bool write, bool diff) > { > BDRVVPCState *s = bs->opaque; > - uint64_t offset = sector_num * 512; > - uint64_t bitmap_offset, block_offset; > + uint64_t offset = sector_num << BDRV_SECTOR_BITS; > + uint64_t bitmap_offset; > uint32_t pagetable_index, pageentry_index; > + int64_t block_offset = LONG_MIN; > + int ret; > > pagetable_index = offset / s->block_size; > - pageentry_index = (offset % s->block_size) / 512; > + pageentry_index = (offset % s->block_size) >> BDRV_SECTOR_BITS; > > - if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff) > - return -1; // not allocated > + if (pagetable_index >= s->max_table_entries) { > + return -2; > + } > + if (s->pagetable[pagetable_index] == 0xffffffff) { > + if (!write && diff) { > + return -3; /* parent allocated */ > + } else { > + return -2; /* not allocated */ > + } > + } > > - bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; > - block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index); > + bitmap_offset = (uint64_t) s->pagetable[pagetable_index] > + << BDRV_SECTOR_BITS; > + > + if (!diff || write) { > + block_offset = bitmap_offset + s->bitmap_size > + + (pageentry_index << BDRV_SECTOR_BITS); > + } else { > + uint32_t bitmap_index, bitmapentry_index; > + uint8_t bitmap[s->bitmap_size]; > > + if (bitmap_offset > s->max_table_entries * s->block_size) { > + return -1; > + } > + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, s->bitmap_size); > + if (ret < 0) { > + return -1; > + } > + > + bitmap_index = pageentry_index / 8; > + bitmapentry_index = 7 - pageentry_index % 8; > + if (bitmap[bitmap_index] & 0x1 << bitmapentry_index) { > + block_offset = bitmap_offset + s->bitmap_size > + + (pageentry_index << BDRV_SECTOR_BITS); > + } else { > + return -3; > + } > + } > // 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)) { > + if (!diff && write && (s->last_bitmap_offset != bitmap_offset)) { > uint8_t bitmap[s->bitmap_size]; > > s->last_bitmap_offset = bitmap_offset; > @@ -376,7 +569,7 @@ static inline int64_t get_sector_offset(BlockDriverState *bs, > bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size); > } > > -// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", > +// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", > // sector_num, pagetable_index, pageentry_index, > // bitmap_offset, block_offset); > > @@ -437,7 +630,8 @@ static int rewrite_footer(BlockDriverState* bs) > * > * Returns the sectors' offset in the image file on success and < 0 on error > */ > -static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) > +static int64_t alloc_block(BlockDriverState *bs, int64_t sector_num, > + bool diff) > { > BDRVVPCState *s = bs->opaque; > int64_t bat_offset; > @@ -457,7 +651,11 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) > s->pagetable[index] = s->free_data_block_offset / 512; > > // Initialize the block's bitmap > - memset(bitmap, 0xff, s->bitmap_size); > + if (diff) { > + memset(bitmap, 0x0, s->bitmap_size); > + } else { > + memset(bitmap, 0xff, s->bitmap_size); > + } > ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap, > s->bitmap_size); > if (ret < 0) { > @@ -477,7 +675,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) > if (ret < 0) > goto fail; > > - return get_sector_offset(bs, sector_num, 0); > + return get_sector_offset(bs, sector_num, false, diff); > > fail: > s->free_data_block_offset -= (s->block_size + s->bitmap_size); > @@ -501,36 +699,66 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num, > uint8_t *buf, int nb_sectors) > { > BDRVVPCState *s = bs->opaque; > - int ret; > - int64_t offset; > - int64_t sectors, sectors_per_block; > VHDFooter *footer = (VHDFooter *) s->footer_buf; > + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > + int64_t offset, sectors; > + int ret; > > - if (be32_to_cpu(footer->type) == VHD_FIXED) { > + switch (be32_to_cpu(footer->type)) { > + case VHD_FIXED: > return bdrv_read(bs->file, sector_num, buf, nb_sectors); > - } > - while (nb_sectors > 0) { > - offset = get_sector_offset(bs, sector_num, 0); > - > - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > - sectors = sectors_per_block - (sector_num % sectors_per_block); > - if (sectors > nb_sectors) { > - sectors = nb_sectors; > - } > + case VHD_DYNAMIC: > + while (nb_sectors > 0) { > + sectors = sectors_per_block - (sector_num % sectors_per_block); > + if (sectors > nb_sectors) { > + sectors = nb_sectors; > + } > > - if (offset == -1) { > - memset(buf, 0, sectors * BDRV_SECTOR_SIZE); > - } else { > - ret = bdrv_pread(bs->file, offset, buf, > - sectors * BDRV_SECTOR_SIZE); > - if (ret != sectors * BDRV_SECTOR_SIZE) { > + offset = get_sector_offset(bs, sector_num, false, false); > + if (offset == -1) { > return -1; > + } else if (offset == -2) { > + memset(buf, 0, sectors * BDRV_SECTOR_SIZE); > + } else { > + ret = bdrv_pread(bs->file, offset, buf, > + sectors * BDRV_SECTOR_SIZE); > + if (ret != sectors * BDRV_SECTOR_SIZE) { > + return -1; > + } > } > + > + nb_sectors -= sectors; > + sector_num += sectors; > + buf += sectors * BDRV_SECTOR_SIZE; > } > + break; > + case VHD_DIFF: > + while (nb_sectors > 0) { > + offset = get_sector_offset(bs, sector_num, false, true); > + if (offset == -1) { > + return -1; > + } else if (offset == -2) { > + memset(buf, 0, BDRV_SECTOR_SIZE); > + } else if (offset == -3) { > + ret = bdrv_pread(bs->backing_hd, sector_num << BDRV_SECTOR_BITS > + , buf, BDRV_SECTOR_SIZE); > + if (ret < 0) { > + return -1; > + } > + } else { > + ret = bdrv_pread(bs->file, offset, buf, BDRV_SECTOR_SIZE); > + if (ret != BDRV_SECTOR_SIZE) { > + return -1; > + } > + } > > - nb_sectors -= sectors; > - sector_num += sectors; > - buf += sectors * BDRV_SECTOR_SIZE; > + nb_sectors--; > + sector_num++; > + buf += BDRV_SECTOR_SIZE; > + } > + break; > + default: > + return -1; > } > return 0; > } > @@ -546,44 +774,101 @@ static coroutine_fn int vpc_co_read(BlockDriverState *bs, int64_t sector_num, > return ret; > } > > -static int vpc_write(BlockDriverState *bs, int64_t sector_num, > - const uint8_t *buf, int nb_sectors) > +static inline int64_t write_bitmap(BlockDriverState *bs, int64_t sector_num, > + int64_t sectors) > { > BDRVVPCState *s = bs->opaque; > - int64_t offset; > - int64_t sectors, sectors_per_block; > + uint64_t offset = sector_num << BDRV_SECTOR_BITS; > + uint64_t bitmap_offset; > + uint32_t pagetable_index, pageentry_index; > + uint8_t bitmap[s->bitmap_size]; > + uint32_t bitmap_index, bitmapbit_index; > + int i; > int ret; > - VHDFooter *footer = (VHDFooter *) s->footer_buf; > > - if (be32_to_cpu(footer->type) == VHD_FIXED) { > - return bdrv_write(bs->file, sector_num, buf, nb_sectors); > + pagetable_index = offset / s->block_size; > + pageentry_index = (offset % s->block_size) / 512; > + bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; > + > + if (bitmap_offset > s->max_table_entries * s->block_size) { > + return -1; > + } > + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, s->bitmap_size); > + if (ret < 0) { > + return -1; > } > - while (nb_sectors > 0) { > - offset = get_sector_offset(bs, sector_num, 1); > > - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > - sectors = sectors_per_block - (sector_num % sectors_per_block); > - if (sectors > nb_sectors) { > - sectors = nb_sectors; > + for (i = 0; i < sectors; i++) { > + bitmap_index = pageentry_index / 8; > + bitmapbit_index = 7 - pageentry_index % 8; > + bitmap[bitmap_index] |= (0x1 << bitmapbit_index); > + pageentry_index++; > + } > + ret = bdrv_pwrite(bs->file, bitmap_offset, bitmap, s->bitmap_size); > + if (ret < 0) { > + return -1; > + } > + > + return 0; > +} > + > +static int vpc_write(BlockDriverState *bs, int64_t sector_num, > + const uint8_t *buf, int nb_sectors) > +{ > + BDRVVPCState *s = bs->opaque; > + VHDFooter *footer = (VHDFooter *) s->footer_buf; > + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > + int64_t offset, sectors; > + bool diff = true; > + int ret = 0; > + > + switch (be32_to_cpu(footer->type)) { > + case VHD_FIXED: > + return bdrv_write(bs->file, sector_num, buf, nb_sectors); > + case VHD_DYNAMIC: > + case VHD_DIFF: > + if (be32_to_cpu(footer->type) == VHD_DYNAMIC) { > + diff = false; > } > > - if (offset == -1) { > - offset = alloc_block(bs, sector_num); > - if (offset < 0) > + while (nb_sectors > 0) { > + sectors = sectors_per_block - (sector_num % sectors_per_block); > + if (sectors > nb_sectors) { > + sectors = nb_sectors; > + } > + > + offset = get_sector_offset(bs, sector_num, true, diff); > + if (offset == -1) { > return -1; > - } > + } else if (offset == -2) { > + offset = alloc_block(bs, sector_num, diff); > + if (offset < 0) { > + return -1; > + } > + } > > - ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE); > - if (ret != sectors * BDRV_SECTOR_SIZE) { > - return -1; > - } > + ret = bdrv_pwrite(bs->file, offset, buf, > + sectors * BDRV_SECTOR_SIZE); > + if (ret != sectors * BDRV_SECTOR_SIZE) { > + return -1; > + } > > - nb_sectors -= sectors; > - sector_num += sectors; > - buf += sectors * BDRV_SECTOR_SIZE; > - } > + if (diff) { > + ret = write_bitmap(bs, sector_num, sectors); > + if (ret < 0) { > + return -1; > + } > + } > > - return 0; > + nb_sectors -= sectors; > + sector_num += sectors; > + buf += sectors * BDRV_SECTOR_SIZE; > + } > + break; > + default: > + return -1; > + } > + return ret; > } > > static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num, > @@ -911,6 +1196,7 @@ static BlockDriver bdrv_vpc = { > .bdrv_close = vpc_close, > .bdrv_reopen_prepare = vpc_reopen_prepare, > .bdrv_create = vpc_create, > + .supports_backing = true, > > .bdrv_read = vpc_co_read, > .bdrv_write = vpc_co_write, > -- > 1.8.3.1 > >
A little bit late for the 7 days of Nation's day, Ding xiao will review my patch. It looks like qcow2 is too popular. :) On Thu, Oct 2, 2014 at 11:36 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote: > On Fri, Sep 26, 2014 at 09:43:18PM +0800, Xiaodong Gong wrote: > > Now qemu only supports vhd type VHD_FIXED and VHD_DYNAMIC, so qemu > > can't read snapshot volume of vhd, and can't support other storage > > features of vhd file. > > > > This patch add read parent information in function "vpc_open", read > > bitmap in "vpc_read", and change bitmap in "vpc_write". > > > > Signed-off-by: Xiaodong Gong <gordongong0350@gmail.com> > > --- > > block/vpc.c | 428 > ++++++++++++++++++++++++++++++++++++++++++++++++++---------- > > 1 file changed, 357 insertions(+), 71 deletions(-) > > Waiting for code review. > > I only consider patches for the block branch that have at least 1 > Reviewed-by from another contributor. > > Anyone? > > > diff --git a/block/vpc.c b/block/vpc.c > > index 4947369..1210542 100644 > > --- a/block/vpc.c > > +++ b/block/vpc.c > > @@ -29,17 +29,27 @@ > > #if defined(CONFIG_UUID) > > #include <uuid/uuid.h> > > #endif > > +#include <iconv.h> > > > > /**************************************************************/ > > > > #define HEADER_SIZE 512 > > +#define DYNAMIC_HEADER_SIZE 1024 > > +#define PARENT_LOCATOR_NUM 8 > > +#define MACX_PREFIX_LEN 7 /* file:// */ > > +#define TBBATMAP_HEAD_SIZE 28 > > + > > +#define PLATFORM_MACX 0x5863614d /* big endian */ > > +#define PLATFORM_W2RU 0x75723257 > > + > > +#define VHD_VERSION(major, minor) (((major) << 16) | ((minor) & > 0x0000FFFF)) > > > > //#define CACHE > > > > enum vhd_type { > > VHD_FIXED = 2, > > VHD_DYNAMIC = 3, > > - VHD_DIFFERENCING = 4, > > + VHD_DIFF = 4, > > }; > > > > // Seconds since Jan 1, 2000 0:00:00 (UTC) > > @@ -138,6 +148,15 @@ typedef struct BDRVVPCState { > > Error *migration_blocker; > > } BDRVVPCState; > > > > +typedef struct vhd_tdbatmap_header { > > + char magic[8]; /* always "tdbatmap" */ > > + > > + uint64_t batmap_offset; > > + uint32_t batmap_size; > > + uint32_t batmap_version; > > + uint32_t checksum; > > +} QEMU_PACKED VHDTdBatmapHeader; > > + > > static uint32_t vpc_checksum(uint8_t* buf, size_t size) > > { > > uint32_t res = 0; > > @@ -153,10 +172,107 @@ static uint32_t vpc_checksum(uint8_t* buf, size_t > size) > > static int vpc_probe(const uint8_t *buf, int buf_size, const char > *filename) > > { > > if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) > > - return 100; > > + return 100; > > return 0; > > } > > > > +static int vpc_read_backing_loc(VHDDynDiskHeader *dyndisk_header, > > + BlockDriverState *bs, > > + Error **errp) > > +{ > > + BDRVVPCState *s = bs->opaque; > > + int64_t data_offset = 0; > > + int data_length = 0; > > + uint32_t platform; > > + bool done = false; > > + int parent_locator_offset = 0; > > + int i; > > + int ret = 0; > > + > > + for (i = 0; i < PARENT_LOCATOR_NUM; i++) { > > + data_offset = > > + be64_to_cpu(dyndisk_header->parent_locator[i].data_offset); > > + data_length = > > + be32_to_cpu(dyndisk_header->parent_locator[i].data_length); > > + platform = dyndisk_header->parent_locator[i].platform; > > + > > + /* Extend the location offset */ > > + if (parent_locator_offset < data_offset) { > > + parent_locator_offset = data_offset; > > + } > > + > > + if (done) { > > + continue; > > + } > > + > > + /* Skip "file://" in MacX platform */ > > + if (platform == PLATFORM_MACX) { > > + data_offset += MACX_PREFIX_LEN; > > + data_length -= MACX_PREFIX_LEN; > > + } > > + > > + /* Read location of backing file */ > > + if (platform == PLATFORM_MACX || platform == PLATFORM_W2RU) { > > + if (data_offset > s->max_table_entries * s->block_size) { > > + return -1; > > + } > > + if (data_length > BDRV_SECTOR_SIZE) { > > + return -1; > > + } > > + ret = bdrv_pread(bs->file, data_offset, bs->backing_file, > > + data_length); > > + if (ret < 0) { > > + return ret; > > + } > > + bs->backing_file[data_length] = '\0'; > > + } > > + > > + /* Convert location to ACSII string */ > > + if (platform == PLATFORM_MACX) { > > + done = true; > > + > > + } else if (platform == PLATFORM_W2RU) { > > + /* Must be UTF16-LE to ASCII */ > > + char *out, *optr; > > + int j; > > + > > + optr = out = (char *) malloc(data_length + 1); > > + if (out == NULL) { > > + ret = -1; > > + return ret; > > + } > > + memset(out, 0, data_length + 1); > > + > > + for (j = 0; j < data_length + 1; j++) { > > + out[j] = bs->backing_file[2*j]; > > + } > > + out[data_length + 1] = '\0'; > > + > > + while (*optr != '\0') { > > + if (*optr == '\\') { > > + *optr = '/'; > > + } > > + optr++; > > + } > > + > > + strncpy(bs->backing_file, out, data_length + 1); > > + > > + out = NULL; > > + free(out); > > + > > + done = true; > > + } > > + } > > + > > + if (bs->backing_file[0] == '\0') { > > + error_setg(errp, "block-vpc: differencing is not support in > w2ku"); > > + ret = -EINVAL; > > + return ret; > > + } > > + > > + return parent_locator_offset; > > +} > > + > > static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > > Error **errp) > > { > > @@ -164,11 +280,14 @@ static int vpc_open(BlockDriverState *bs, QDict > *options, int flags, > > int i; > > VHDFooter *footer; > > VHDDynDiskHeader *dyndisk_header; > > - uint8_t buf[HEADER_SIZE]; > > + uint8_t buf[DYNAMIC_HEADER_SIZE]; > > + uint8_t tdbatmap_header_buf[TBBATMAP_HEAD_SIZE]; > > uint32_t checksum; > > uint64_t computed_size; > > - int disk_type = VHD_DYNAMIC; > > + uint32_t disk_type; > > int ret; > > + VHDTdBatmapHeader *tdbatmap_header; > > + int parent_locator_offset = 0; > > > > ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); > > if (ret < 0) { > > @@ -176,6 +295,8 @@ static int vpc_open(BlockDriverState *bs, QDict > *options, int flags, > > } > > > > footer = (VHDFooter *) s->footer_buf; > > + disk_type = be32_to_cpu(footer->type); > > + > > if (strncmp(footer->creator, "conectix", 8)) { > > int64_t offset = bdrv_getlength(bs->file); > > if (offset < 0) { > > @@ -230,9 +351,9 @@ static int vpc_open(BlockDriverState *bs, QDict > *options, int flags, > > goto fail; > > } > > > > - if (disk_type == VHD_DYNAMIC) { > > + if (disk_type == VHD_DYNAMIC || disk_type == VHD_DIFF) { > > ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), > buf, > > - HEADER_SIZE); > > + DYNAMIC_HEADER_SIZE); > > if (ret < 0) { > > goto fail; > > } > > @@ -286,6 +407,37 @@ static int vpc_open(BlockDriverState *bs, QDict > *options, int flags, > > s->free_data_block_offset = > > (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; > > > > + /* Read tdbatmap header by offset */ > > + if (footer->version >= VHD_VERSION(1, 2)) { > > + ret = bdrv_pread(bs->file, s->free_data_block_offset, > > + tdbatmap_header_buf, TBBATMAP_HEAD_SIZE); > > + if (ret < 0) { > > + goto fail; > > + } > > + > > + tdbatmap_header = (VHDTdBatmapHeader *) tdbatmap_header_buf; > > + if (!strncmp(tdbatmap_header->magic, "tdbatmap", 8)) { > > + s->free_data_block_offset = > > + be32_to_cpu(tdbatmap_header->batmap_size) * 512 > > + + be64_to_cpu(tdbatmap_header->batmap_offset); > > + } > > + } > > + > > + /* Read backing file location from dyn header table */ > > + if (dyndisk_header->parent_name[0] || > dyndisk_header->parent_name[1]) { > > + ret = parent_locator_offset = > vpc_read_backing_loc(dyndisk_header, > > + bs, errp); > > + if (ret < 0) { > > + goto fail; > > + } > > + } > > + > > + if (s->free_data_block_offset < parent_locator_offset > > + + BDRV_SECTOR_SIZE) { > > + s->free_data_block_offset = parent_locator_offset > > + + BDRV_SECTOR_SIZE; > > + } > > + > > for (i = 0; i < s->max_table_entries; i++) { > > be32_to_cpus(&s->pagetable[i]); > > if (s->pagetable[i] != 0xFFFFFFFF) { > > @@ -340,35 +492,76 @@ static int vpc_reopen_prepare(BDRVReopenState > *state, > > } > > > > /* > > - * Returns the absolute byte offset of the given sector in the image > file. > > - * If the sector is not allocated, -1 is returned instead. > > + * Returns the absolute byte offset of the given sector in the > differencing > > + * image file. > > + * > > + * If error happened, -1 is returned. > > + * > > + * When write all type or read dynamic, if the sector is not allocated, > -2 > > + * is returned instead. If the sector is allocated in current file, the > block > > + * offset is returned. > > * > > - * The parameter write must be 1 if the offset will be used for a write > > - * operation (the block bitmaps is updated then), 0 otherwise. > > + * When read diff. If the sector is not allocated, -2 is returned > instead. > > + * If the sector is allocated in the backing file, -3 is returned. If > the > > + * sector is allocated in current file, the block offset is returned. > > */ > > static inline int64_t get_sector_offset(BlockDriverState *bs, > > - int64_t sector_num, int write) > > + int64_t sector_num, bool write, bool diff) > > { > > BDRVVPCState *s = bs->opaque; > > - uint64_t offset = sector_num * 512; > > - uint64_t bitmap_offset, block_offset; > > + uint64_t offset = sector_num << BDRV_SECTOR_BITS; > > + uint64_t bitmap_offset; > > uint32_t pagetable_index, pageentry_index; > > + int64_t block_offset = LONG_MIN; > > + int ret; > > > > pagetable_index = offset / s->block_size; > > - pageentry_index = (offset % s->block_size) / 512; > > + pageentry_index = (offset % s->block_size) >> BDRV_SECTOR_BITS; > > > > - if (pagetable_index >= s->max_table_entries || > s->pagetable[pagetable_index] == 0xffffffff) > > - return -1; // not allocated > > + if (pagetable_index >= s->max_table_entries) { > > + return -2; > > + } > > + if (s->pagetable[pagetable_index] == 0xffffffff) { > > + if (!write && diff) { > > + return -3; /* parent allocated */ > > + } else { > > + return -2; /* not allocated */ > > + } > > + } > > > > - bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; > > - block_offset = bitmap_offset + s->bitmap_size + (512 * > pageentry_index); > > + bitmap_offset = (uint64_t) s->pagetable[pagetable_index] > > + << BDRV_SECTOR_BITS; > > + > > + if (!diff || write) { > > + block_offset = bitmap_offset + s->bitmap_size > > + + (pageentry_index << BDRV_SECTOR_BITS); > > + } else { > > + uint32_t bitmap_index, bitmapentry_index; > > + uint8_t bitmap[s->bitmap_size]; > > > > + if (bitmap_offset > s->max_table_entries * s->block_size) { > > + return -1; > > + } > > + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, > s->bitmap_size); > > + if (ret < 0) { > > + return -1; > > + } > > + > > + bitmap_index = pageentry_index / 8; > > + bitmapentry_index = 7 - pageentry_index % 8; > > + if (bitmap[bitmap_index] & 0x1 << bitmapentry_index) { > > + block_offset = bitmap_offset + s->bitmap_size > > + + (pageentry_index << BDRV_SECTOR_BITS); > > + } else { > > + return -3; > > + } > > + } > > // 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)) { > > + if (!diff && write && (s->last_bitmap_offset != bitmap_offset)) { > > uint8_t bitmap[s->bitmap_size]; > > > > s->last_bitmap_offset = bitmap_offset; > > @@ -376,7 +569,7 @@ static inline int64_t > get_sector_offset(BlockDriverState *bs, > > bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, > s->bitmap_size); > > } > > > > -// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" > PRIx64 ", bloff: %" PRIx64 "\n", > > +// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" > PRIx64 ", bloff: %" PRIx64 "\n", > > // sector_num, pagetable_index, pageentry_index, > > // bitmap_offset, block_offset); > > > > @@ -437,7 +630,8 @@ static int rewrite_footer(BlockDriverState* bs) > > * > > * Returns the sectors' offset in the image file on success and < 0 on > error > > */ > > -static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) > > +static int64_t alloc_block(BlockDriverState *bs, int64_t sector_num, > > + bool diff) > > { > > BDRVVPCState *s = bs->opaque; > > int64_t bat_offset; > > @@ -457,7 +651,11 @@ static int64_t alloc_block(BlockDriverState* bs, > int64_t sector_num) > > s->pagetable[index] = s->free_data_block_offset / 512; > > > > // Initialize the block's bitmap > > - memset(bitmap, 0xff, s->bitmap_size); > > + if (diff) { > > + memset(bitmap, 0x0, s->bitmap_size); > > + } else { > > + memset(bitmap, 0xff, s->bitmap_size); > > + } > > ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap, > > s->bitmap_size); > > if (ret < 0) { > > @@ -477,7 +675,7 @@ static int64_t alloc_block(BlockDriverState* bs, > int64_t sector_num) > > if (ret < 0) > > goto fail; > > > > - return get_sector_offset(bs, sector_num, 0); > > + return get_sector_offset(bs, sector_num, false, diff); > > > > fail: > > s->free_data_block_offset -= (s->block_size + s->bitmap_size); > > @@ -501,36 +699,66 @@ static int vpc_read(BlockDriverState *bs, int64_t > sector_num, > > uint8_t *buf, int nb_sectors) > > { > > BDRVVPCState *s = bs->opaque; > > - int ret; > > - int64_t offset; > > - int64_t sectors, sectors_per_block; > > VHDFooter *footer = (VHDFooter *) s->footer_buf; > > + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > > + int64_t offset, sectors; > > + int ret; > > > > - if (be32_to_cpu(footer->type) == VHD_FIXED) { > > + switch (be32_to_cpu(footer->type)) { > > + case VHD_FIXED: > > return bdrv_read(bs->file, sector_num, buf, nb_sectors); > > - } > > - while (nb_sectors > 0) { > > - offset = get_sector_offset(bs, sector_num, 0); > > - > > - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > > - sectors = sectors_per_block - (sector_num % sectors_per_block); > > - if (sectors > nb_sectors) { > > - sectors = nb_sectors; > > - } > > + case VHD_DYNAMIC: > > + while (nb_sectors > 0) { > > + sectors = sectors_per_block - (sector_num % > sectors_per_block); > > + if (sectors > nb_sectors) { > > + sectors = nb_sectors; > > + } > > > > - if (offset == -1) { > > - memset(buf, 0, sectors * BDRV_SECTOR_SIZE); > > - } else { > > - ret = bdrv_pread(bs->file, offset, buf, > > - sectors * BDRV_SECTOR_SIZE); > > - if (ret != sectors * BDRV_SECTOR_SIZE) { > > + offset = get_sector_offset(bs, sector_num, false, false); > > + if (offset == -1) { > > return -1; > > + } else if (offset == -2) { > > + memset(buf, 0, sectors * BDRV_SECTOR_SIZE); > > + } else { > > + ret = bdrv_pread(bs->file, offset, buf, > > + sectors * BDRV_SECTOR_SIZE); > > + if (ret != sectors * BDRV_SECTOR_SIZE) { > > + return -1; > > + } > > } > > + > > + nb_sectors -= sectors; > > + sector_num += sectors; > > + buf += sectors * BDRV_SECTOR_SIZE; > > } > > + break; > > + case VHD_DIFF: > > + while (nb_sectors > 0) { > > + offset = get_sector_offset(bs, sector_num, false, true); > > + if (offset == -1) { > > + return -1; > > + } else if (offset == -2) { > > + memset(buf, 0, BDRV_SECTOR_SIZE); > > + } else if (offset == -3) { > > + ret = bdrv_pread(bs->backing_hd, sector_num << > BDRV_SECTOR_BITS > > + , buf, BDRV_SECTOR_SIZE); > > + if (ret < 0) { > > + return -1; > > + } > > + } else { > > + ret = bdrv_pread(bs->file, offset, buf, > BDRV_SECTOR_SIZE); > > + if (ret != BDRV_SECTOR_SIZE) { > > + return -1; > > + } > > + } > > > > - nb_sectors -= sectors; > > - sector_num += sectors; > > - buf += sectors * BDRV_SECTOR_SIZE; > > + nb_sectors--; > > + sector_num++; > > + buf += BDRV_SECTOR_SIZE; > > + } > > + break; > > + default: > > + return -1; > > } > > return 0; > > } > > @@ -546,44 +774,101 @@ static coroutine_fn int > vpc_co_read(BlockDriverState *bs, int64_t sector_num, > > return ret; > > } > > > > -static int vpc_write(BlockDriverState *bs, int64_t sector_num, > > - const uint8_t *buf, int nb_sectors) > > +static inline int64_t write_bitmap(BlockDriverState *bs, int64_t > sector_num, > > + int64_t sectors) > > { > > BDRVVPCState *s = bs->opaque; > > - int64_t offset; > > - int64_t sectors, sectors_per_block; > > + uint64_t offset = sector_num << BDRV_SECTOR_BITS; > > + uint64_t bitmap_offset; > > + uint32_t pagetable_index, pageentry_index; > > + uint8_t bitmap[s->bitmap_size]; > > + uint32_t bitmap_index, bitmapbit_index; > > + int i; > > int ret; > > - VHDFooter *footer = (VHDFooter *) s->footer_buf; > > > > - if (be32_to_cpu(footer->type) == VHD_FIXED) { > > - return bdrv_write(bs->file, sector_num, buf, nb_sectors); > > + pagetable_index = offset / s->block_size; > > + pageentry_index = (offset % s->block_size) / 512; > > + bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; > > + > > + if (bitmap_offset > s->max_table_entries * s->block_size) { > > + return -1; > > + } > > + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, s->bitmap_size); > > + if (ret < 0) { > > + return -1; > > } > > - while (nb_sectors > 0) { > > - offset = get_sector_offset(bs, sector_num, 1); > > > > - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > > - sectors = sectors_per_block - (sector_num % sectors_per_block); > > - if (sectors > nb_sectors) { > > - sectors = nb_sectors; > > + for (i = 0; i < sectors; i++) { > > + bitmap_index = pageentry_index / 8; > > + bitmapbit_index = 7 - pageentry_index % 8; > > + bitmap[bitmap_index] |= (0x1 << bitmapbit_index); > > + pageentry_index++; > > + } > > + ret = bdrv_pwrite(bs->file, bitmap_offset, bitmap, s->bitmap_size); > > + if (ret < 0) { > > + return -1; > > + } > > + > > + return 0; > > +} > > + > > +static int vpc_write(BlockDriverState *bs, int64_t sector_num, > > + const uint8_t *buf, int nb_sectors) > > +{ > > + BDRVVPCState *s = bs->opaque; > > + VHDFooter *footer = (VHDFooter *) s->footer_buf; > > + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; > > + int64_t offset, sectors; > > + bool diff = true; > > + int ret = 0; > > + > > + switch (be32_to_cpu(footer->type)) { > > + case VHD_FIXED: > > + return bdrv_write(bs->file, sector_num, buf, nb_sectors); > > + case VHD_DYNAMIC: > > + case VHD_DIFF: > > + if (be32_to_cpu(footer->type) == VHD_DYNAMIC) { > > + diff = false; > > } > > > > - if (offset == -1) { > > - offset = alloc_block(bs, sector_num); > > - if (offset < 0) > > + while (nb_sectors > 0) { > > + sectors = sectors_per_block - (sector_num % > sectors_per_block); > > + if (sectors > nb_sectors) { > > + sectors = nb_sectors; > > + } > > + > > + offset = get_sector_offset(bs, sector_num, true, diff); > > + if (offset == -1) { > > return -1; > > - } > > + } else if (offset == -2) { > > + offset = alloc_block(bs, sector_num, diff); > > + if (offset < 0) { > > + return -1; > > + } > > + } > > > > - ret = bdrv_pwrite(bs->file, offset, buf, sectors * > BDRV_SECTOR_SIZE); > > - if (ret != sectors * BDRV_SECTOR_SIZE) { > > - return -1; > > - } > > + ret = bdrv_pwrite(bs->file, offset, buf, > > + sectors * BDRV_SECTOR_SIZE); > > + if (ret != sectors * BDRV_SECTOR_SIZE) { > > + return -1; > > + } > > > > - nb_sectors -= sectors; > > - sector_num += sectors; > > - buf += sectors * BDRV_SECTOR_SIZE; > > - } > > + if (diff) { > > + ret = write_bitmap(bs, sector_num, sectors); > > + if (ret < 0) { > > + return -1; > > + } > > + } > > > > - return 0; > > + nb_sectors -= sectors; > > + sector_num += sectors; > > + buf += sectors * BDRV_SECTOR_SIZE; > > + } > > + break; > > + default: > > + return -1; > > + } > > + return ret; > > } > > > > static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t > sector_num, > > @@ -911,6 +1196,7 @@ static BlockDriver bdrv_vpc = { > > .bdrv_close = vpc_close, > > .bdrv_reopen_prepare = vpc_reopen_prepare, > > .bdrv_create = vpc_create, > > + .supports_backing = true, > > > > .bdrv_read = vpc_co_read, > > .bdrv_write = vpc_co_write, > > -- > > 1.8.3.1 > > > > >
diff --git a/block/vpc.c b/block/vpc.c index 4947369..1210542 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -29,17 +29,27 @@ #if defined(CONFIG_UUID) #include <uuid/uuid.h> #endif +#include <iconv.h> /**************************************************************/ #define HEADER_SIZE 512 +#define DYNAMIC_HEADER_SIZE 1024 +#define PARENT_LOCATOR_NUM 8 +#define MACX_PREFIX_LEN 7 /* file:// */ +#define TBBATMAP_HEAD_SIZE 28 + +#define PLATFORM_MACX 0x5863614d /* big endian */ +#define PLATFORM_W2RU 0x75723257 + +#define VHD_VERSION(major, minor) (((major) << 16) | ((minor) & 0x0000FFFF)) //#define CACHE enum vhd_type { VHD_FIXED = 2, VHD_DYNAMIC = 3, - VHD_DIFFERENCING = 4, + VHD_DIFF = 4, }; // Seconds since Jan 1, 2000 0:00:00 (UTC) @@ -138,6 +148,15 @@ typedef struct BDRVVPCState { Error *migration_blocker; } BDRVVPCState; +typedef struct vhd_tdbatmap_header { + char magic[8]; /* always "tdbatmap" */ + + uint64_t batmap_offset; + uint32_t batmap_size; + uint32_t batmap_version; + uint32_t checksum; +} QEMU_PACKED VHDTdBatmapHeader; + static uint32_t vpc_checksum(uint8_t* buf, size_t size) { uint32_t res = 0; @@ -153,10 +172,107 @@ static uint32_t vpc_checksum(uint8_t* buf, size_t size) static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) { if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) - return 100; + return 100; return 0; } +static int vpc_read_backing_loc(VHDDynDiskHeader *dyndisk_header, + BlockDriverState *bs, + Error **errp) +{ + BDRVVPCState *s = bs->opaque; + int64_t data_offset = 0; + int data_length = 0; + uint32_t platform; + bool done = false; + int parent_locator_offset = 0; + int i; + int ret = 0; + + for (i = 0; i < PARENT_LOCATOR_NUM; i++) { + data_offset = + be64_to_cpu(dyndisk_header->parent_locator[i].data_offset); + data_length = + be32_to_cpu(dyndisk_header->parent_locator[i].data_length); + platform = dyndisk_header->parent_locator[i].platform; + + /* Extend the location offset */ + if (parent_locator_offset < data_offset) { + parent_locator_offset = data_offset; + } + + if (done) { + continue; + } + + /* Skip "file://" in MacX platform */ + if (platform == PLATFORM_MACX) { + data_offset += MACX_PREFIX_LEN; + data_length -= MACX_PREFIX_LEN; + } + + /* Read location of backing file */ + if (platform == PLATFORM_MACX || platform == PLATFORM_W2RU) { + if (data_offset > s->max_table_entries * s->block_size) { + return -1; + } + if (data_length > BDRV_SECTOR_SIZE) { + return -1; + } + ret = bdrv_pread(bs->file, data_offset, bs->backing_file, + data_length); + if (ret < 0) { + return ret; + } + bs->backing_file[data_length] = '\0'; + } + + /* Convert location to ACSII string */ + if (platform == PLATFORM_MACX) { + done = true; + + } else if (platform == PLATFORM_W2RU) { + /* Must be UTF16-LE to ASCII */ + char *out, *optr; + int j; + + optr = out = (char *) malloc(data_length + 1); + if (out == NULL) { + ret = -1; + return ret; + } + memset(out, 0, data_length + 1); + + for (j = 0; j < data_length + 1; j++) { + out[j] = bs->backing_file[2*j]; + } + out[data_length + 1] = '\0'; + + while (*optr != '\0') { + if (*optr == '\\') { + *optr = '/'; + } + optr++; + } + + strncpy(bs->backing_file, out, data_length + 1); + + out = NULL; + free(out); + + done = true; + } + } + + if (bs->backing_file[0] == '\0') { + error_setg(errp, "block-vpc: differencing is not support in w2ku"); + ret = -EINVAL; + return ret; + } + + return parent_locator_offset; +} + static int vpc_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { @@ -164,11 +280,14 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, int i; VHDFooter *footer; VHDDynDiskHeader *dyndisk_header; - uint8_t buf[HEADER_SIZE]; + uint8_t buf[DYNAMIC_HEADER_SIZE]; + uint8_t tdbatmap_header_buf[TBBATMAP_HEAD_SIZE]; uint32_t checksum; uint64_t computed_size; - int disk_type = VHD_DYNAMIC; + uint32_t disk_type; int ret; + VHDTdBatmapHeader *tdbatmap_header; + int parent_locator_offset = 0; ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); if (ret < 0) { @@ -176,6 +295,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, } footer = (VHDFooter *) s->footer_buf; + disk_type = be32_to_cpu(footer->type); + if (strncmp(footer->creator, "conectix", 8)) { int64_t offset = bdrv_getlength(bs->file); if (offset < 0) { @@ -230,9 +351,9 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - if (disk_type == VHD_DYNAMIC) { + if (disk_type == VHD_DYNAMIC || disk_type == VHD_DIFF) { ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, - HEADER_SIZE); + DYNAMIC_HEADER_SIZE); if (ret < 0) { goto fail; } @@ -286,6 +407,37 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, s->free_data_block_offset = (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; + /* Read tdbatmap header by offset */ + if (footer->version >= VHD_VERSION(1, 2)) { + ret = bdrv_pread(bs->file, s->free_data_block_offset, + tdbatmap_header_buf, TBBATMAP_HEAD_SIZE); + if (ret < 0) { + goto fail; + } + + tdbatmap_header = (VHDTdBatmapHeader *) tdbatmap_header_buf; + if (!strncmp(tdbatmap_header->magic, "tdbatmap", 8)) { + s->free_data_block_offset = + be32_to_cpu(tdbatmap_header->batmap_size) * 512 + + be64_to_cpu(tdbatmap_header->batmap_offset); + } + } + + /* Read backing file location from dyn header table */ + if (dyndisk_header->parent_name[0] || dyndisk_header->parent_name[1]) { + ret = parent_locator_offset = vpc_read_backing_loc(dyndisk_header, + bs, errp); + if (ret < 0) { + goto fail; + } + } + + if (s->free_data_block_offset < parent_locator_offset + + BDRV_SECTOR_SIZE) { + s->free_data_block_offset = parent_locator_offset + + BDRV_SECTOR_SIZE; + } + for (i = 0; i < s->max_table_entries; i++) { be32_to_cpus(&s->pagetable[i]); if (s->pagetable[i] != 0xFFFFFFFF) { @@ -340,35 +492,76 @@ static int vpc_reopen_prepare(BDRVReopenState *state, } /* - * Returns the absolute byte offset of the given sector in the image file. - * If the sector is not allocated, -1 is returned instead. + * Returns the absolute byte offset of the given sector in the differencing + * image file. + * + * If error happened, -1 is returned. + * + * When write all type or read dynamic, if the sector is not allocated, -2 + * is returned instead. If the sector is allocated in current file, the block + * offset is returned. * - * The parameter write must be 1 if the offset will be used for a write - * operation (the block bitmaps is updated then), 0 otherwise. + * When read diff. If the sector is not allocated, -2 is returned instead. + * If the sector is allocated in the backing file, -3 is returned. If the + * sector is allocated in current file, the block offset is returned. */ static inline int64_t get_sector_offset(BlockDriverState *bs, - int64_t sector_num, int write) + int64_t sector_num, bool write, bool diff) { BDRVVPCState *s = bs->opaque; - uint64_t offset = sector_num * 512; - uint64_t bitmap_offset, block_offset; + uint64_t offset = sector_num << BDRV_SECTOR_BITS; + uint64_t bitmap_offset; uint32_t pagetable_index, pageentry_index; + int64_t block_offset = LONG_MIN; + int ret; pagetable_index = offset / s->block_size; - pageentry_index = (offset % s->block_size) / 512; + pageentry_index = (offset % s->block_size) >> BDRV_SECTOR_BITS; - if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff) - return -1; // not allocated + if (pagetable_index >= s->max_table_entries) { + return -2; + } + if (s->pagetable[pagetable_index] == 0xffffffff) { + if (!write && diff) { + return -3; /* parent allocated */ + } else { + return -2; /* not allocated */ + } + } - bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; - block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index); + bitmap_offset = (uint64_t) s->pagetable[pagetable_index] + << BDRV_SECTOR_BITS; + + if (!diff || write) { + block_offset = bitmap_offset + s->bitmap_size + + (pageentry_index << BDRV_SECTOR_BITS); + } else { + uint32_t bitmap_index, bitmapentry_index; + uint8_t bitmap[s->bitmap_size]; + if (bitmap_offset > s->max_table_entries * s->block_size) { + return -1; + } + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, s->bitmap_size); + if (ret < 0) { + return -1; + } + + bitmap_index = pageentry_index / 8; + bitmapentry_index = 7 - pageentry_index % 8; + if (bitmap[bitmap_index] & 0x1 << bitmapentry_index) { + block_offset = bitmap_offset + s->bitmap_size + + (pageentry_index << BDRV_SECTOR_BITS); + } else { + return -3; + } + } // 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)) { + if (!diff && write && (s->last_bitmap_offset != bitmap_offset)) { uint8_t bitmap[s->bitmap_size]; s->last_bitmap_offset = bitmap_offset; @@ -376,7 +569,7 @@ static inline int64_t get_sector_offset(BlockDriverState *bs, bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size); } -// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", +// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", // sector_num, pagetable_index, pageentry_index, // bitmap_offset, block_offset); @@ -437,7 +630,8 @@ static int rewrite_footer(BlockDriverState* bs) * * Returns the sectors' offset in the image file on success and < 0 on error */ -static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) +static int64_t alloc_block(BlockDriverState *bs, int64_t sector_num, + bool diff) { BDRVVPCState *s = bs->opaque; int64_t bat_offset; @@ -457,7 +651,11 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) s->pagetable[index] = s->free_data_block_offset / 512; // Initialize the block's bitmap - memset(bitmap, 0xff, s->bitmap_size); + if (diff) { + memset(bitmap, 0x0, s->bitmap_size); + } else { + memset(bitmap, 0xff, s->bitmap_size); + } ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap, s->bitmap_size); if (ret < 0) { @@ -477,7 +675,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) if (ret < 0) goto fail; - return get_sector_offset(bs, sector_num, 0); + return get_sector_offset(bs, sector_num, false, diff); fail: s->free_data_block_offset -= (s->block_size + s->bitmap_size); @@ -501,36 +699,66 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { BDRVVPCState *s = bs->opaque; - int ret; - int64_t offset; - int64_t sectors, sectors_per_block; VHDFooter *footer = (VHDFooter *) s->footer_buf; + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; + int64_t offset, sectors; + int ret; - if (be32_to_cpu(footer->type) == VHD_FIXED) { + switch (be32_to_cpu(footer->type)) { + case VHD_FIXED: return bdrv_read(bs->file, sector_num, buf, nb_sectors); - } - while (nb_sectors > 0) { - offset = get_sector_offset(bs, sector_num, 0); - - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; - sectors = sectors_per_block - (sector_num % sectors_per_block); - if (sectors > nb_sectors) { - sectors = nb_sectors; - } + case VHD_DYNAMIC: + while (nb_sectors > 0) { + sectors = sectors_per_block - (sector_num % sectors_per_block); + if (sectors > nb_sectors) { + sectors = nb_sectors; + } - if (offset == -1) { - memset(buf, 0, sectors * BDRV_SECTOR_SIZE); - } else { - ret = bdrv_pread(bs->file, offset, buf, - sectors * BDRV_SECTOR_SIZE); - if (ret != sectors * BDRV_SECTOR_SIZE) { + offset = get_sector_offset(bs, sector_num, false, false); + if (offset == -1) { return -1; + } else if (offset == -2) { + memset(buf, 0, sectors * BDRV_SECTOR_SIZE); + } else { + ret = bdrv_pread(bs->file, offset, buf, + sectors * BDRV_SECTOR_SIZE); + if (ret != sectors * BDRV_SECTOR_SIZE) { + return -1; + } } + + nb_sectors -= sectors; + sector_num += sectors; + buf += sectors * BDRV_SECTOR_SIZE; } + break; + case VHD_DIFF: + while (nb_sectors > 0) { + offset = get_sector_offset(bs, sector_num, false, true); + if (offset == -1) { + return -1; + } else if (offset == -2) { + memset(buf, 0, BDRV_SECTOR_SIZE); + } else if (offset == -3) { + ret = bdrv_pread(bs->backing_hd, sector_num << BDRV_SECTOR_BITS + , buf, BDRV_SECTOR_SIZE); + if (ret < 0) { + return -1; + } + } else { + ret = bdrv_pread(bs->file, offset, buf, BDRV_SECTOR_SIZE); + if (ret != BDRV_SECTOR_SIZE) { + return -1; + } + } - nb_sectors -= sectors; - sector_num += sectors; - buf += sectors * BDRV_SECTOR_SIZE; + nb_sectors--; + sector_num++; + buf += BDRV_SECTOR_SIZE; + } + break; + default: + return -1; } return 0; } @@ -546,44 +774,101 @@ static coroutine_fn int vpc_co_read(BlockDriverState *bs, int64_t sector_num, return ret; } -static int vpc_write(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) +static inline int64_t write_bitmap(BlockDriverState *bs, int64_t sector_num, + int64_t sectors) { BDRVVPCState *s = bs->opaque; - int64_t offset; - int64_t sectors, sectors_per_block; + uint64_t offset = sector_num << BDRV_SECTOR_BITS; + uint64_t bitmap_offset; + uint32_t pagetable_index, pageentry_index; + uint8_t bitmap[s->bitmap_size]; + uint32_t bitmap_index, bitmapbit_index; + int i; int ret; - VHDFooter *footer = (VHDFooter *) s->footer_buf; - if (be32_to_cpu(footer->type) == VHD_FIXED) { - return bdrv_write(bs->file, sector_num, buf, nb_sectors); + pagetable_index = offset / s->block_size; + pageentry_index = (offset % s->block_size) / 512; + bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; + + if (bitmap_offset > s->max_table_entries * s->block_size) { + return -1; + } + ret = bdrv_pread(bs->file, bitmap_offset, bitmap, s->bitmap_size); + if (ret < 0) { + return -1; } - while (nb_sectors > 0) { - offset = get_sector_offset(bs, sector_num, 1); - sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; - sectors = sectors_per_block - (sector_num % sectors_per_block); - if (sectors > nb_sectors) { - sectors = nb_sectors; + for (i = 0; i < sectors; i++) { + bitmap_index = pageentry_index / 8; + bitmapbit_index = 7 - pageentry_index % 8; + bitmap[bitmap_index] |= (0x1 << bitmapbit_index); + pageentry_index++; + } + ret = bdrv_pwrite(bs->file, bitmap_offset, bitmap, s->bitmap_size); + if (ret < 0) { + return -1; + } + + return 0; +} + +static int vpc_write(BlockDriverState *bs, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + BDRVVPCState *s = bs->opaque; + VHDFooter *footer = (VHDFooter *) s->footer_buf; + int64_t sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; + int64_t offset, sectors; + bool diff = true; + int ret = 0; + + switch (be32_to_cpu(footer->type)) { + case VHD_FIXED: + return bdrv_write(bs->file, sector_num, buf, nb_sectors); + case VHD_DYNAMIC: + case VHD_DIFF: + if (be32_to_cpu(footer->type) == VHD_DYNAMIC) { + diff = false; } - if (offset == -1) { - offset = alloc_block(bs, sector_num); - if (offset < 0) + while (nb_sectors > 0) { + sectors = sectors_per_block - (sector_num % sectors_per_block); + if (sectors > nb_sectors) { + sectors = nb_sectors; + } + + offset = get_sector_offset(bs, sector_num, true, diff); + if (offset == -1) { return -1; - } + } else if (offset == -2) { + offset = alloc_block(bs, sector_num, diff); + if (offset < 0) { + return -1; + } + } - ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE); - if (ret != sectors * BDRV_SECTOR_SIZE) { - return -1; - } + ret = bdrv_pwrite(bs->file, offset, buf, + sectors * BDRV_SECTOR_SIZE); + if (ret != sectors * BDRV_SECTOR_SIZE) { + return -1; + } - nb_sectors -= sectors; - sector_num += sectors; - buf += sectors * BDRV_SECTOR_SIZE; - } + if (diff) { + ret = write_bitmap(bs, sector_num, sectors); + if (ret < 0) { + return -1; + } + } - return 0; + nb_sectors -= sectors; + sector_num += sectors; + buf += sectors * BDRV_SECTOR_SIZE; + } + break; + default: + return -1; + } + return ret; } static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num, @@ -911,6 +1196,7 @@ static BlockDriver bdrv_vpc = { .bdrv_close = vpc_close, .bdrv_reopen_prepare = vpc_reopen_prepare, .bdrv_create = vpc_create, + .supports_backing = true, .bdrv_read = vpc_co_read, .bdrv_write = vpc_co_write,
Now qemu only supports vhd type VHD_FIXED and VHD_DYNAMIC, so qemu can't read snapshot volume of vhd, and can't support other storage features of vhd file. This patch add read parent information in function "vpc_open", read bitmap in "vpc_read", and change bitmap in "vpc_write". Signed-off-by: Xiaodong Gong <gordongong0350@gmail.com> --- block/vpc.c | 428 ++++++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 357 insertions(+), 71 deletions(-)