block: Allow mapping of vmalloc-ed buffers

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 vmalloc().

To do so, detect vmalloc-ed buffers using is_vmalloc_addr(). For
vmalloc-ed buffers, flush the buffer using flush_kernel_vmap_range(),
use vmalloc_to_page() instead of virt_to_page() to obtain the pages of
the buffer, and invalidate the buffer addresses with
invalidate_kernel_vmap_range() on completion of read BIOs. This last
point is executed using the function bio_invalidate_vmalloc_pages()
which is defined only if the architecture defines
ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE, that is, if the architecture
actually needs the invalidation done.

Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
Fixes: e76239a3748c ("block: add a report_zones method")
Cc: [email protected]
Reviewed-by: Martin K. Petersen <[email protected]>
Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions