Ekaterina Tumanova <tuman...@linux.vnet.ibm.com> writes:
> Add driver functions for geometry and blocksize detection
>
> Signed-off-by: Ekaterina Tumanova <tuman...@linux.vnet.ibm.com>
> ---
> block.c | 35 +++++++++++++++++++++++++++++++++++
> include/block/block.h | 13 +++++++++++++
> include/block/block_int.h | 5 +++++
> 3 files changed, 53 insertions(+)
>
> diff --git a/block.c b/block.c
> index a612594..7b0b804 100644
> --- a/block.c
> +++ b/block.c
> @@ -548,6 +548,41 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error
> **errp)
> }
> }
>
> +/**
> + * Try to get @bs's logical and physical block size.
> + * On success, store them in bsz struct.
@bsz
> + * On failure, set default blocksize.
> + */
Suggest not to talk about failure here. Like this:
/**
* Get @bs's logical and physical block size, store them in @bsz.
*/
> +void bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
> +{
> + BlockDriver *drv = bs->drv;
> +
> + assert(drv != NULL);
Dies when @bs is empty (no medium). Either return default block sizes
instead, or amend the function contract with "@bs must not be empty."
Should've caught that in v2, sorry.
> + if (drv->bdrv_probe_blocksizes &&
> + !drv->bdrv_probe_blocksizes(bs, bsz)) {
> + return;
> + }
> + bsz->log = BDRV_SECTOR_SIZE;
> + bsz->phys = BDRV_SECTOR_SIZE;
> +}
> +
> +/**
> + * Try to get @bs's geometry (cyls, heads, sectos)
> + * On success, store them in geo struct and return 0.
... store it in @geo and ...
> + * On failure return -errno.
> + */
> +int bdrv_probe_geometry(BlockDriverState *bs, hdGeometry *geo)
> +{
> + BlockDriver *drv = bs->drv;
> +
> + assert(drv != NULL);
Dies when @bs is empty (no medium). Either return -ENOMEDIUM instead,
or amend the function contract with "@bs must not be empty." The former
seems simpler to me.
> + if (drv->bdrv_probe_geometry) {
> + return drv->bdrv_probe_geometry(bs, geo);
> + }
> +
> + return -1;
This is not a negative errno! I'd return -ENOTSUP.
> +}
> +
> /*
> * Create a uniquely-named empty temporary file.
> * Return 0 upon success, otherwise a negative errno value.
> diff --git a/include/block/block.h b/include/block/block.h
> index 5450610..17184b6 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -60,6 +60,17 @@ typedef enum {
> BDRV_REQ_MAY_UNMAP = 0x4,
> } BdrvRequestFlags;
>
> +typedef struct BlockSizes {
> + uint32_t phys;
> + uint32_t log;
> +} BlockSizes;
> +
> +typedef struct hdGeometry {
> + uint32_t heads;
> + uint32_t sectors;
> + uint32_t cylinders;
> +} hdGeometry;
> +
> #define BDRV_O_RDWR 0x0002
> #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes
> in a snapshot */
> #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
> @@ -538,6 +549,8 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs);
> * the old #AioContext is not executing.
> */
> void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
> +void bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
> +int bdrv_probe_geometry(BlockDriverState *bs, hdGeometry *geo);
>
> void bdrv_io_plug(BlockDriverState *bs);
> void bdrv_io_unplug(BlockDriverState *bs);
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index a1c17b9..16e53e9 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -271,6 +271,11 @@ struct BlockDriver {
> void (*bdrv_io_unplug)(BlockDriverState *bs);
> void (*bdrv_flush_io_queue)(BlockDriverState *bs);
>
> + /* try to get physical and logical blocksizes */
> + int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
I recommend a function contract, not just a paraphrasing of the function
name. The one you put in block.c needs just a small touchup to fit
here nicely:
/**
* Try to get @bs's logical and physical block size.
* On success, store them in @bsz and return zero.
* On failure, return negative errno.
*/
> + /* tey to get hard drive geometry (cyls, head, sectors) */
s/tey/try/
> + int (*bdrv_probe_geometry)(BlockDriverState *bs, hdGeometry *geo);
> +
/**
* Try to get @bs's geometry (cyls, heads, sectos)
* On success, store them in @geo and return 0.
* On failure return -errno.
*/
> QLIST_ENTRY(BlockDriver) list;
> };
