[U-Boot] [PATCH v2 8/8] fs/fat: fix case for FAT shortnames

[Łukasz Majewski]

On 09/02/2017 06:38 PM, Rob Clark wrote:
> Noticed when comparing our output to linux.  There are some lcase bits
> which control whether filename and/or extension should be downcase'd.

Reviewed-by: Łukasz Majewski <lukma at denx.de>

> 
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
>   fs/fat/fat.c       | 17 ++++++++++++-----
>   fs/fat/fat_write.c |  4 ++--
>   include/fat.h      |  3 +++
>   3 files changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/fat/fat.c b/fs/fat/fat.c
> index fc3106aacb..ccbf7ba1c8 100644
> --- a/fs/fat/fat.c
> +++ b/fs/fat/fat.c
> @@ -29,11 +29,13 @@ static const int vfat_enabled = 0;
>   #endif
>   
>   /*
> - * Convert a string to lowercase.
> + * Convert a string to lowercase.  Converts at most 'len' characters,
> + * 'len' may be larger than the length of 'str' if 'str' is NULL
> + * terminated.
>    */
> -static void downcase(char *str)
> +static void downcase(char *str, size_t len)
>   {
> -	while (*str != '\0') {
> +	while (*str != '\0' && len--) {
>   		*str = tolower(*str);
>   		str++;
>   	}
> @@ -131,10 +133,16 @@ static void get_name(dir_entry *dirent, char *s_name)
>   	ptr = s_name;
>   	while (*ptr && *ptr != ' ')
>   		ptr++;
> +	if (dirent->lcase & CASE_LOWER_BASE)
> +		downcase(s_name, (unsigned)(ptr - s_name));
>   	if (dirent->ext[0] && dirent->ext[0] != ' ') {
> +		char *ext;
> +
>   		*ptr = '.';
> -		ptr++;
> +		ext = ++ptr;
>   		memcpy(ptr, dirent->ext, 3);
> +		if (dirent->lcase & CASE_LOWER_EXT)
> +			downcase(ext, 3);
>   		ptr[3] = '\0';
>   		while (*ptr && *ptr != ' ')
>   			ptr++;
> @@ -144,7 +152,6 @@ static void get_name(dir_entry *dirent, char *s_name)
>   		*s_name = '\0';
>   	else if (*s_name == aRING)
>   		*s_name = DELETED_FLAG;
> -	downcase(s_name);
>   }
>   
>   static int flush_dirty_fat_buffer(fsdata *mydata);
> diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
> index 4ca024c208..655ad4ec84 100644
> --- a/fs/fat/fat_write.c
> +++ b/fs/fat/fat_write.c
> @@ -345,7 +345,7 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
>   		*l_name = '\0';
>   	else if (*l_name == aRING)
>   		*l_name = DELETED_FLAG;
> -	downcase(l_name);
> +	downcase(l_name, ~0);
>   
>   	/* Return the real directory entry */
>   	*retdent = realdent;
> @@ -981,7 +981,7 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
>   
>   	memcpy(l_filename, filename, name_len);
>   	l_filename[name_len] = 0; /* terminate the string */
> -	downcase(l_filename);
> +	downcase(l_filename, ~0);
>   
>   	startsect = mydata->rootdir_sect;
>   	retdent = find_directory_entry(mydata, startsect,
> diff --git a/include/fat.h b/include/fat.h
> index b2d4b952fd..5e4924316a 100644
> --- a/include/fat.h
> +++ b/include/fat.h
> @@ -128,6 +128,9 @@ typedef struct volume_info
>   	/* Boot sign comes last, 2 bytes */
>   } volume_info;
>   
> +#define CASE_LOWER_BASE	8	/* base is lower case */
> +#define CASE_LOWER_EXT	16	/* extension is lower case */
> +
>   typedef struct dir_entry {
>   	char	name[8],ext[3];	/* Name and extension */
>   	__u8	attr;		/* Attribute bits */
> 


-- 
Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de