Re: [PATCH] state: backend_bucket_direct: add debug prints on read/write

[Johannes Zink <j.zink@xxxxxxxxxxxxxx>]

Hi Ahmad,

thanks for your patch.

On 7/28/23 15:31, Ahmad Fatoum wrote:
> We already have debug prints for the circular backend to help see how
> much data is read/written for each bucket. Add similar debugging info
> for the direct backend as well. Example with stride size of 2048 and
> 44 bytes for the variable set:
>
>    barebox@board:/ state -l
>    state: Read state from 0 length 68
>    state: Read state from 2048 length 68
>    state: Read state from 4096 length 68
>
>    barebox@board:/ state -s
>    state: Written state to offset 0 length 68 data length 60
>    state: Written state to offset 2048 length 68 data length 60
>    state: Written state to offset 4096 length 68 data length 60
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
>   common/state/backend_bucket_direct.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/common/state/backend_bucket_direct.c b/common/state/backend_bucket_direct.c
> index f06e14277862..03c752d6fe41 100644
> --- a/common/state/backend_bucket_direct.c
> +++ b/common/state/backend_bucket_direct.c
> @@ -52,7 +52,7 @@ static int state_backend_bucket_direct_read(struct state_backend_storage_bucket
>   	struct state_backend_storage_bucket_direct *direct =
>   	    get_bucket_direct(bucket);
>   	struct state_backend_storage_bucket_direct_meta meta;
> -	uint32_t read_len;
> +	uint32_t read_len, header_len = 0;
>   	void *buf;
>   	int ret;
>   
> @@ -72,6 +72,8 @@ static int state_backend_bucket_direct_read(struct state_backend_storage_bucket
>   			return -EINVAL;
>   
>   		}
> +
> +		header_len = sizeof(meta);
>   	} else {
>   		if (meta.magic != ~0 && !!meta.magic)
>   			bucket->wrong_magic = 1;
> @@ -87,12 +89,16 @@ static int state_backend_bucket_direct_read(struct state_backend_storage_bucket
>   				-errno);
>   			return -errno;
>   		}
> +
>   	}
>   
>   	buf = xmalloc(read_len);
>   	if (!buf)
>   		return -ENOMEM;
>   
> +	dev_dbg(direct->dev, "Read state from %lld length %d\n", (long long) direct->offset,
> +		header_len + read_len);
> +

maybe this could use the same message format as for writing (i.e. total length 
and data length pointed out separately)?

Best regards
Johannes

>   	ret = read_full(direct->fd, buf, read_len);
>   	if (ret < 0) {
>   		dev_err(direct->dev, "Failed to read from file, %d\n", ret);
> @@ -112,6 +118,7 @@ static int state_backend_bucket_direct_write(struct state_backend_storage_bucket
>   {
>   	struct state_backend_storage_bucket_direct *direct =
>   	    get_bucket_direct(bucket);
> +	size_t header_len = 0;
>   	int ret;
>   	struct state_backend_storage_bucket_direct_meta meta;
>   
> @@ -129,6 +136,8 @@ static int state_backend_bucket_direct_write(struct state_backend_storage_bucket
>   			dev_err(direct->dev, "Failed to write metadata to file, %d\n", ret);
>   			return ret;
>   		}
> +
> +		header_len = sizeof(meta);
>   	} else {
>   		if (!IS_ENABLED(CONFIG_STATE_BACKWARD_COMPATIBLE)) {
>   			dev_dbg(direct->dev, "Too small stride size: must skip metadata! Increase stride size\n");
> @@ -148,6 +157,9 @@ static int state_backend_bucket_direct_write(struct state_backend_storage_bucket
>   		return ret;
>   	}
>   
> +	dev_dbg(direct->dev, "Written state to offset %lld length %zu data length %zu\n",
> +		(long long)direct->offset, len + header_len, len);
> +
>   	return 0;
>   }
>   

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