On 04/06/2018 04:41 AM, Sayan Ghosh wrote:
> The patch is on top of Linux Kernel 4.7.2.
>
> Signed-off-by: Sayan Ghosh <sgdgp.2014@xxxxxxxxx>
> ---
> fs/ext4/ext4.h | 1 +
> fs/ext4/extents.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 114 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index de9194f..aaff3a3 100755
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -58,6 +58,12 @@
> #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
>
> /*
> + * Starting block numbers for low and high grades
> + */
> +#define LOW_GRADE_STARTING_BLOCK 0
> +#define HIGH_GRADE_STARTING_BLOCK 1249280
> +
> +/*
> * read_grade_xattr() is used to read the grade array from the
> extended attribute.
> */
> void read_grade_xattr(struct inode *inode,struct grade_struct *grade_array)
> @@ -92,6 +98,43 @@ unsigned long long read_count_xattr(struct inode *inode)
> return total;
> }
>
> +/*
> + * find_grade() is to find the grade of a logical block.
> + * This also returns the length of graded or ungraded portion
> + * starting from that logical block number (gets stored in the variable
> + * req_len). The return value is 1 for high grade and 0 otherwise.
> + */
Lots of style issues:
> +int find_grade(struct grade_struct* grade_array, unsigned long long
> total, ext4_fsblk_t val, unsigned long long *req_len)
line too long.
> +{
> + if (val >= (grade_array[total -1].block_num + grade_array[total -1].len) ){
> + if (req_len != NULL)
> + (*req_len) = 0;
> + return 0;
> + }
use tabs, not spaces. and indentation should be 8, not 4. (many places)
> + unsigned long long beg, end, mid;
Don't declare variables after code.
> + beg = 0;
> + end = total-1;
> + while (beg <= end){
> + mid = (beg + end)/2;
> + if ((val >= grade_array[mid].block_num) && (val <=
> (grade_array[mid].block_num + grade_array[mid].len - 1)) ){
line too long.
> + if (req_len != NULL)
> + (*req_len) = grade_array[mid].len;
> + return 1;
> + }
> + if(beg == end)
space after "if"
> + break;
> + if (grade_array[mid].block_num > val){
> + end = (mid > 0) ? (mid - 1) : 0;
> + }
> + else{
> + beg = mid + 1;
> + }
> + }
> + if (req_len != NULL)
> + (*req_len) = grade_array[mid].block_num - val;
> + return 0;
> +}
> +
> static __le32 ext4_extent_block_csum(struct inode *inode,
> struct ext4_extent_header *eh)
> {
--
~Randy
