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Re: [Qemu-devel] [PATCH 2/6] VMDK: add twoGbMaxExtentSparse support
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH 2/6] VMDK: add twoGbMaxExtentSparse support |
Date: |
Tue, 2 Aug 2011 11:32:43 +0100 |
On Wed, Jul 27, 2011 at 10:27 AM, Fam Zheng <address@hidden> wrote:
> Add twoGbMaxExtentSparse support. Only opening code is changed.
>
> Signed-off-by: Fam Zheng <address@hidden>
> ---
> block/vmdk.c | 124
> ++++++++++++++++++++++++++++++++++++----------------------
> 1 files changed, 77 insertions(+), 47 deletions(-)
>
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 9e6c67a..9d1ae32 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -357,7 +357,9 @@ static int vmdk_init_tables(BlockDriverState *bs,
> VmdkExtent *extent)
> return ret;
> }
>
> -static int vmdk_open_vmdk3(BlockDriverState *bs, int flags)
> +static int vmdk_open_vmdk3(BlockDriverState *bs,
> + BlockDriverState *file,
> + int flags)
> {
> int ret;
> uint32_t magic;
> @@ -365,10 +367,9 @@ static int vmdk_open_vmdk3(BlockDriverState *bs, int
> flags)
> BDRVVmdkState *s = bs->opaque;
> VmdkExtent *extent;
>
> - s->desc_offset = 0x200;
> - ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
> + ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
> if (ret < 0) {
> - goto fail;
> + return ret;
> }
> extent = vmdk_add_extent(bs,
> bs->file, false,
> @@ -378,17 +379,16 @@ static int vmdk_open_vmdk3(BlockDriverState *bs, int
> flags)
> le32_to_cpu(header.granularity));
> ret = vmdk_init_tables(bs, extent);
> if (ret) {
> - /* vmdk_init_tables cleans up on fail, so only free allocation of
> - * vmdk_add_extent here. */
> - goto fail;
> + /* free extent allocated by vmdk_add_extent */
> + s->num_extents--;
> + qemu_realloc(s->extents, s->num_extents * sizeof(VmdkExtent));
The return value of qemu_realloc() is the new address of s->extents[].
You are ignoring the new address and continue to use the old one.
Please add a vmdk_free_last_extent() function that encapsulates this.
The rest of the vmdk.c code should not manipulate
s->extents[]/s->num_extents. Use vmdk_add_extent(),
vmdk_free_last_extent(), vmdk_free_extents() instead of spreading the
extent management code in various places.
> }
> - return 0;
> - fail:
> - vmdk_free_extents(bs);
> return ret;
> }
>
> -static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
> +static int vmdk_open_vmdk4(BlockDriverState *bs,
> + BlockDriverState *file,
> + int flags)
> {
> int ret;
> uint32_t magic;
> @@ -397,39 +397,30 @@ static int vmdk_open_vmdk4(BlockDriverState *bs, int
> flags)
> BDRVVmdkState *s = bs->opaque;
> VmdkExtent *extent;
>
> - s->desc_offset = 0x200;
> - ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
> + ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
> if (ret < 0) {
> - goto fail;
> + return ret;
> }
> l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte)
> * le64_to_cpu(header.granularity);
> + if (l1_entry_sectors <= 0) {
> + return -EINVAL;
> + }
> l1_size = (le64_to_cpu(header.capacity) + l1_entry_sectors - 1)
> / l1_entry_sectors;
> - extent = vmdk_add_extent(bs, bs->file, false,
> + extent = vmdk_add_extent(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) {
> - ret = -EINVAL;
> - goto fail;
> - }
> - /* try to open parent images, if exist */
> - ret = vmdk_parent_open(bs);
> - if (ret) {
> - goto fail;
> - }
> - s->parent_cid = vmdk_read_cid(bs, 1);
> ret = vmdk_init_tables(bs, extent);
> if (ret) {
> - goto fail;
> + /* free extent allocated by vmdk_add_extent */
> + s->num_extents--;
> + qemu_realloc(s->extents, s->num_extents * sizeof(VmdkExtent));
Same bug.
> }
> - return 0;
> - fail:
> - vmdk_free_extents(bs);
> return ret;
> }
>
> @@ -460,6 +451,35 @@ static int vmdk_parse_description(const char *desc,
> const char *opt_name,
> return 0;
> }
>
> +/* Open an extent file and append to bs array */
> +static int vmdk_open_sparse(BlockDriverState *bs,
> + BlockDriverState *file,
> + int flags)
> +{
> + int ret;
> + uint32_t magic;
> +
> + if (bdrv_pread(file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
> + return -EIO;
> + }
> +
> + magic = be32_to_cpu(magic);
> + if (magic == VMDK3_MAGIC) {
> + ret = vmdk_open_vmdk3(bs, file, flags);
> + if (ret) {
> + return ret;
> + }
> + } else if (magic == VMDK4_MAGIC) {
> + ret = vmdk_open_vmdk4(bs, file, flags);
> + if (ret) {
> + return ret;
> + }
> + } else {
> + return -EINVAL;
> + }
> + return 0;
Shorter way of writing this (ret is no longer necessary):
switch (magic) {
case VMDK3_MAGIC:
return vmdk_open_vmdk3(bs, file, flags);
case VMDK4_MAGIC:
return vmdk_open_vmdk4(bs, file, flags);
default:
return -EINVAL;
}
> +}
> +
> static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
> const char *desc_file_path)
> {
> @@ -470,6 +490,8 @@ static int vmdk_parse_extents(const char *desc,
> BlockDriverState *bs,
> const char *p = desc;
> int64_t sectors = 0;
> int64_t flat_offset;
> + char extent_path[PATH_MAX];
> + BlockDriverState *extent_file;
>
> while (*p) {
> /* parse extent line:
> @@ -504,22 +526,28 @@ static int vmdk_parse_extents(const char *desc,
> BlockDriverState *bs,
> goto next_line;
> }
>
> + path_combine(extent_path, sizeof(extent_path),
> + desc_file_path, fname);
> + ret = bdrv_file_open(&extent_file, extent_path, bs->open_flags);
> + if (ret) {
> + return ret;
> + }
> +
> /* save to extents array */
> if (!strcmp(type, "FLAT")) {
> /* FLAT extent */
> - char extent_path[PATH_MAX];
> - BlockDriverState *extent_file;
> VmdkExtent *extent;
>
> - path_combine(extent_path, sizeof(extent_path),
> - desc_file_path, fname);
> - ret = bdrv_file_open(&extent_file, extent_path, bs->open_flags);
> - if (ret) {
> - return ret;
> - }
> extent = vmdk_add_extent(bs, extent_file, true, sectors,
> 0, 0, 0, 0, sectors);
> extent->flat_start_offset = flat_offset;
> + } else if (!strcmp(type, "SPARSE")) {
> + /* SPARSE extent */
> + ret = vmdk_open_sparse(bs, extent_file, bs->open_flags);
> + if (ret) {
> + bdrv_delete(extent_file);
> + return ret;
> + }
> } else {
> /* SPARSE extent, not supported for now */
This comment is outdated.
> fprintf(stderr,
> @@ -552,6 +580,7 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int
> flags)
> return -EINVAL;
> }
> if (strcmp(ct, "monolithicFlat") &&
> + strcmp(ct, "twoGbMaxExtentSparse") &&
> strcmp(ct, "twoGbMaxExtentFlat")) {
> fprintf(stderr,
> "VMDK: Not supported image type \"%s\""".\n", ct);
> @@ -574,17 +603,18 @@ static int vmdk_open_desc_file(BlockDriverState *bs,
> int flags)
>
> static int vmdk_open(BlockDriverState *bs, int flags)
> {
> - uint32_t magic;
> -
> - if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
> - return -EIO;
> - }
> + int ret;
> + BDRVVmdkState *s = bs->opaque;
>
> - magic = be32_to_cpu(magic);
> - if (magic == VMDK3_MAGIC) {
> - return vmdk_open_vmdk3(bs, flags);
> - } else if (magic == VMDK4_MAGIC) {
> - return vmdk_open_vmdk4(bs, flags);
> + if (vmdk_open_sparse(bs, bs->file, flags) == 0) {
> + s->desc_offset = 0x200;
> + /* try to open parent images, if exist */
> + ret = vmdk_parent_open(bs);
> + if (ret) {
> + return ret;
What needs to be freed here?
Stefan
- Re: [Qemu-devel] [PATCH 2/6] VMDK: add twoGbMaxExtentSparse support,
Stefan Hajnoczi <=