Looks good with one nit, can be done at the time of applying patch.
Reviewed-by: Chaitanya Kulkarni <[email protected]>
On 6/24/19 7:46 PM, Damien Le Moal wrote:
> To allow the SCSI subsystem scsi_execute_req() function to issue
> requests using large buffers that are better allocated with vmalloc()
> rather than kmalloc(), modify bio_map_kern() to allow passing a buffer
> allocated with the vmalloc() function. To do so, simply test the buffer
> address using is_vmalloc_addr() and use vmalloc_to_page() instead of
> virt_to_page() to obtain the pages of vmalloc-ed buffers.
>
> Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer
> allocation")
> Fixes: e76239a3748c ("block: add a report_zones method")
> Cc: [email protected]
> Signed-off-by: Damien Le Moal <[email protected]>
> ---
> block/bio.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index ce797d73bb43..05afcaf655f3 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -1501,6 +1501,8 @@ struct bio *bio_map_kern(struct request_queue *q, void
> *data, unsigned int len,
> unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> unsigned long start = kaddr >> PAGE_SHIFT;
> const int nr_pages = end - start;
> + bool is_vmalloc = is_vmalloc_addr(data); > + struct page *page;
> int offset, i;
> struct bio *bio;
>
> @@ -1518,7 +1520,11 @@ struct bio *bio_map_kern(struct request_queue *q, void
> *data, unsigned int len,
> if (bytes > len)
> bytes = len;
>
> - if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
> + if (is_vmalloc)
nit:- Can we use is_vmalloc_addr() call directly so that
"if (is_vmalloc)" -> "if (is_vmalloc_addr(data))" and remove is_vmalloc
variable.
> + page = vmalloc_to_page(data);
> + else
> + page = virt_to_page(data);
> + if (bio_add_pc_page(q, bio, page, bytes,
> offset) < bytes) {
> /* we don't support partial mappings */
> bio_put(bio);
>
