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authorDamien Le Moal <damien.lemoal@wdc.com>2019-07-01 08:09:15 +0300
committerJens Axboe <axboe@kernel.dk>2019-07-12 05:04:36 +0300
commitb4c5875d36178e8df409bdce232f270cac89fafe (patch)
tree3dcf8838b6b74b38b4c1db5d154ecee93e15922c /block/bio.c
parente7bf90e5afe3aa1d1282c1635a49e17a32c4ecec (diff)
downloadlinux-b4c5875d36178e8df409bdce232f270cac89fafe.tar.xz
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 <martin.petersen@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c28
1 files changed, 27 insertions, 1 deletions
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 <linux/workqueue.h>
#include <linux/cgroup.h>
#include <linux/blk-cgroup.h>
+#include <linux/highmem.h>
#include <trace/events/block.h>
#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);