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-rw-r--r--block/bio.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c
index bd3d048d0a72..26782ff85dbf 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1319,6 +1319,36 @@ int submit_bio_wait(struct bio *bio)
}
EXPORT_SYMBOL(submit_bio_wait);
+/**
+ * bdev_rw_virt - synchronously read into / write from kernel mapping
+ * @bdev: block device to access
+ * @sector: sector to access
+ * @data: data to read/write
+ * @len: length in byte to read/write
+ * @op: operation (e.g. REQ_OP_READ/REQ_OP_WRITE)
+ *
+ * Performs synchronous I/O to @bdev for @data/@len. @data must be in
+ * the kernel direct mapping and not a vmalloc address.
+ */
+int bdev_rw_virt(struct block_device *bdev, sector_t sector, void *data,
+ size_t len, enum req_op op)
+{
+ struct bio_vec bv;
+ struct bio bio;
+ int error;
+
+ if (WARN_ON_ONCE(is_vmalloc_addr(data)))
+ return -EIO;
+
+ bio_init(&bio, bdev, &bv, 1, op);
+ bio.bi_iter.bi_sector = sector;
+ bio_add_virt_nofail(&bio, data, len);
+ error = submit_bio_wait(&bio);
+ bio_uninit(&bio);
+ return error;
+}
+EXPORT_SYMBOL_GPL(bdev_rw_virt);
+
static void bio_wait_end_io(struct bio *bio)
{
complete(bio->bi_private);