On Fri, Feb 07, 2020 at 03:26:47PM -0500, Vivek Goyal wrote:
> Currently pmem_do_write() is written with assumption that all I/O is
> sector aligned. Soon I want to use this function in zero_page_range()
> where range passed in does not have to be sector aligned.
>
> Modify this function to be able to deal with an arbitrary range. Which
> is specified by pmem_off and len.
>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> drivers/nvdimm/pmem.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index 9ad07cb8c9fc..281fe04d25fd 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -154,15 +154,23 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem,
>
> static blk_status_t pmem_do_write(struct pmem_device *pmem,
> struct page *page, unsigned int page_off,
> - sector_t sector, unsigned int len)
> + u64 pmem_off, unsigned int len)
> {
> blk_status_t rc = BLK_STS_OK;
> bool bad_pmem = false;
> - phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
> - void *pmem_addr = pmem->virt_addr + pmem_off;
> -
> - if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
> - bad_pmem = true;
> + phys_addr_t pmem_real_off = pmem_off + pmem->data_offset;
> + void *pmem_addr = pmem->virt_addr + pmem_real_off;
> + sector_t sector_start, sector_end;
> + unsigned nr_sectors;
> +
> + sector_start = DIV_ROUND_UP(pmem_off, SECTOR_SIZE);
> + sector_end = (pmem_off + len) >> SECTOR_SHIFT;
> + if (sector_end > sector_start) {
> + nr_sectors = sector_end - sector_start;
> + if (unlikely(is_bad_pmem(&pmem->bb, sector_start,
> + nr_sectors << SECTOR_SHIFT)))
> + bad_pmem = true;
I don't think an unlikely annotation makes much sense for assigning
a boolean value to a flag variable.
> + /*
> + * Pass sector aligned offset and length. That seems
> + * to work as of now. Other finer grained alignment
> + * cases can be addressed later if need be.
> + */
This comment seems pretty scary. What other cases can you think of?
