[iov_iter] new primitives - copy_from_iter_full() and friends
copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.
Convert some obvious users. *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case. Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index bd82dd1..10b2576 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -667,7 +667,7 @@
return -ENOMEM;
}
- if (unlikely(copy_from_iter(buf, len, from) != len)) {
+ if (unlikely(!copy_from_iter_full(buf, len, from))) {
value = -EFAULT;
goto out;
}