void __user *ubuf, unsigned int len)
{
unsigned long uaddr;
+ unsigned int alignment;
struct bio *bio, *orig_bio;
int reading, ret;
* direct dma. else, set up kernel bounce buffers
*/
uaddr = (unsigned long) ubuf;
- if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))
+ alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+ if (!(uaddr & alignment) && !(len & alignment))
bio = bio_map_user(q, NULL, uaddr, len, reading);
else
bio = bio_copy_user(q, uaddr, len, reading);
ubuf += ret;
}
+ /*
+ * __blk_rq_map_user() copies the buffers if starting address
+ * or length isn't aligned to dma_pad_mask. As the copied
+ * buffer is always page aligned, we know that there's enough
+ * room for padding. Extend the last bio and update
+ * rq->data_len accordingly.
+ *
+ * On unmap, bio_uncopy_user() will use unmodified
+ * bio_map_data pointed to by bio->bi_private.
+ */
+ if (len & q->dma_pad_mask) {
+ unsigned int pad_len = (q->dma_pad_mask & ~len) + 1;
+ struct bio *tail = rq->biotail;
+
+ tail->bi_io_vec[tail->bi_vcnt - 1].bv_len += pad_len;
+ tail->bi_size += pad_len;
+
+ rq->extra_len += pad_len;
+ }
+
rq->buffer = rq->data = NULL;
return 0;
unmap_rq:
blk_rq_unmap_user(bio);
+ rq->bio = NULL;
return ret;
}
-
EXPORT_SYMBOL(blk_rq_map_user);
/**
/* we don't allow misaligned data like bio_map_user() does. If the
* user is using sg, they're expected to know the alignment constraints
* and respect them accordingly */
- bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ);
+ bio = bio_map_user_iov(q, NULL, iov, iov_count,
+ rq_data_dir(rq) == READ);
if (IS_ERR(bio))
return PTR_ERR(bio);
return 0;
}
-EXPORT_SYMBOL(blk_rq_map_user_iov);
-
/**
* blk_rq_unmap_user - unmap a request with user data
* @bio: start of bio list
return ret;
}
-
EXPORT_SYMBOL(blk_rq_unmap_user);
/**
rq->buffer = rq->data = NULL;
return 0;
}
-
EXPORT_SYMBOL(blk_rq_map_kern);