Copy user data to bio
struct bio * bio_copy_user(struct request_queue * q, struct rq_map_data * map_data, unsigned long uaddr, unsigned int len, int write_to_vm, gfp_t gfp_mask);
q
destination block queue
map_data
pointer to the rq_map_data holding pages (if necessary)
uaddr
start of user address
len
length in bytes
write_to_vm
bool indicating writing to pages or not
gfp_mask
memory allocation flags
Prepares and returns a bio for indirect user io, bouncing data to/from kernel pages as necessary. Must be paired with call bio_uncopy_user on io completion.