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: stable@xxxxxxxxxxxxxxx
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
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)
+ 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);
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
