Re: [Qemu-devel] [PATCH v2] Fix for qemu-img info to supply FORMAT values for SPARSE extents

[Fam Zheng]

On Tue, 04/01 17:49, Shwetha Mathangi Chandra Choodamani wrote:
> This patch fixes the bug in qemu-img info that wouldn't populate the extent 
> type for default formats.
> The extent type has now been set where necessary. This is the second version 
> in the series after inputs
> from Fam Zheng(address@hidden).
> 
> Signed-off-by: Shwetha Mathangi Chandra Choodamani <address@hidden>
> ---
>  block/vmdk.c |   53 +++++++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 49 insertions(+), 4 deletions(-)
> 
> diff --git a/block/vmdk.c b/block/vmdk.c
> index b69988d..d4a37ad 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -499,6 +499,18 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
>      VMDK3Header header;
>      VmdkExtent *extent;
>  

IIRC VMFS always comes with a description file, so we won't miss the extent
type and this part is not necessary.

> +    char access[11];
> +    char type[11];
> +    char fname[512];
> +    int64_t sectors = 0;
> +    int64_t flat_offset;
> +    int64_t size;
> +    size = bdrv_getlength(file);
> +    char *buf;
> +    buf = g_malloc0(size + 1);
> +    bdrv_pread(file, sizeof(magic), buf, size);
> +    sscanf(buf, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" SCNd64,
> +    access, &sectors, type, fname, &flat_offset);
>      ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
>      if (ret < 0) {
>          error_setg_errno(errp, -ret,
> @@ -515,6 +527,18 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
>                            le32_to_cpu(header.granularity),
>                            &extent,
>                            errp);
> +    while (strcmp(access, "RW")) {
> +        while (*buf) {
> +            sscanf(buf, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" SCNd64,
> +            access, &sectors, type, fname, &flat_offset);
> +            if (*buf == '\n') {
> +                buf++;
> +                break;
> +            }
> +            buf++;
> +        }
> +    }
> +    extent->type = g_strdup(type);
>      if (ret < 0) {
>          return ret;
>      }
> @@ -523,6 +547,7 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
>          /* free extent allocated by vmdk_add_extent */
>          vmdk_free_last_extent(bs);
>      }
> +    g_free(buf);
>      return ret;
>  }
>  
> @@ -566,7 +591,11 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
>      VmdkExtent *extent;
>      BDRVVmdkState *s = bs->opaque;
>      int64_t l1_backup_offset = 0;
> -
> +    char access[11];
> +    char type[11];
> +    char fname[512];
> +    int64_t sectors = 0;
> +    int64_t flat_offset;
>      ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
>      if (ret < 0) {
>          error_setg_errno(errp, -ret,
> @@ -586,11 +615,9 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
>              return ret;
>          }
>      }
> -

Unnecessary blank line change.

>      if (!s->create_type) {
>          s->create_type = g_strdup("monolithicSparse");
>      }
> -

Same here.

>      if (le64_to_cpu(header.gd_offset) == VMDK4_GD_AT_END) {
>          /*
>           * The footer takes precedence over the header, so read it in. The
> @@ -694,6 +721,25 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
>          g_free(s->create_type);
>          s->create_type = g_strdup("streamOptimized");
>      }
> +
> +    if (!extent->type) {
> +        uint64_t desc_offset = le64_to_cpu(header.desc_offset);
> +        char *buf = vmdk_read_desc(file, desc_offset<<9, errp);
> +        sscanf(buf, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" SCNd64,
> +        access, &sectors, type, fname, &flat_offset);
> +        while (strcmp(access, "RW")) {
> +            while (*buf) {
> +                sscanf(buf, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" 
> SCNd64,
> +                access, &sectors, type, fname, &flat_offset);
> +                if (*buf == '\n') {
> +                    buf++;
> +                    break;
> +                }
> +                buf++;
> +            }
> +        }
> +    }

No. Why do you need to read the description?

Here we already know the extent type by looking at s->create_type, it would be
"monolithicSparse" or "streamOptimized" in the cases that we are trying to fix
in this patch, so no need to parse the description text.

Just set extent->type according to s->create_type.

> +    extent->type = g_strdup(type);


>      extent->has_marker = le32_to_cpu(header.flags) & VMDK4_FLAG_MARKER;
>      extent->version = le32_to_cpu(header.version);
>      extent->has_zero_grain = le32_to_cpu(header.flags) & 
> VMDK4_FLAG_ZERO_GRAIN;
> @@ -711,7 +757,6 @@ static int vmdk_parse_description(const char *desc, const 
> char *opt_name,
>  {
>      char *opt_pos, *opt_end;
>      const char *end = desc + strlen(desc);
> -

Blank line change, please drop it.

Fam

>      opt_pos = strstr(desc, opt_name);
>      if (!opt_pos) {
>          return VMDK_ERROR;
> -- 
> 1.7.9.5
> 
>