From b4c5875d36178e8df409bdce232f270cac89fafe Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 1 Jul 2019 14:09:15 +0900 Subject: 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: stable@vger.kernel.org Reviewed-by: Martin K. Petersen Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Ming Lei Signed-off-by: Jens Axboe --- block/bio.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/bio.c b/block/bio.c index 29cd6cf4da51..299a0e7651ec 100644 --- a/block/bio.c +++ b/block/bio.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "blk.h" @@ -1441,8 +1442,22 @@ void bio_unmap_user(struct bio *bio) bio_put(bio); } +static void bio_invalidate_vmalloc_pages(struct bio *bio) +{ +#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE + if (bio->bi_private && !op_is_write(bio_op(bio))) { + unsigned long i, len = 0; + + for (i = 0; i < bio->bi_vcnt; i++) + len += bio->bi_io_vec[i].bv_len; + invalidate_kernel_vmap_range(bio->bi_private, len); + } +#endif +} + static void bio_map_kern_endio(struct bio *bio) { + bio_invalidate_vmalloc_pages(bio); bio_put(bio); } @@ -1463,6 +1478,8 @@ 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; @@ -1470,6 +1487,11 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, if (!bio) return ERR_PTR(-ENOMEM); + if (is_vmalloc) { + flush_kernel_vmap_range(data, len); + bio->bi_private = data; + } + offset = offset_in_page(kaddr); for (i = 0; i < nr_pages; i++) { unsigned int bytes = PAGE_SIZE - offset; @@ -1480,7 +1502,11 @@ 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) + page = virt_to_page(data); + else + page = vmalloc_to_page(data); + if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) { /* we don't support partial mappings */ bio_put(bio); -- cgit v1.2.3-59-g8ed1b