switch pipe_read() to copy_page_to_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/pipe.c b/fs/pipe.c
index 6679c95..034bffa 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -142,55 +142,6 @@
return 0;
}
-static int
-pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len,
- int atomic)
-{
- unsigned long copy;
-
- while (len > 0) {
- while (!iov->iov_len)
- iov++;
- copy = min_t(unsigned long, len, iov->iov_len);
-
- if (atomic) {
- if (__copy_to_user_inatomic(iov->iov_base, from, copy))
- return -EFAULT;
- } else {
- if (copy_to_user(iov->iov_base, from, copy))
- return -EFAULT;
- }
- from += copy;
- len -= copy;
- iov->iov_base += copy;
- iov->iov_len -= copy;
- }
- return 0;
-}
-
-/*
- * Attempt to pre-fault in the user memory, so we can use atomic copies.
- * Returns the number of bytes not faulted in.
- */
-static int iov_fault_in_pages_write(struct iovec *iov, unsigned long len)
-{
- while (!iov->iov_len)
- iov++;
-
- while (len > 0) {
- unsigned long this_len;
-
- this_len = min_t(unsigned long, len, iov->iov_len);
- if (fault_in_pages_writeable(iov->iov_base, this_len))
- break;
-
- len -= this_len;
- iov++;
- }
-
- return len;
-}
-
/*
* Pre-fault in the user memory, so we can use atomic copies.
*/
@@ -329,12 +280,15 @@
ssize_t ret;
struct iovec *iov = (struct iovec *)_iov;
size_t total_len;
+ struct iov_iter iter;
total_len = iov_length(iov, nr_segs);
/* Null read succeeds. */
if (unlikely(total_len == 0))
return 0;
+ iov_iter_init(&iter, iov, nr_segs, total_len, 0);
+
do_wakeup = 0;
ret = 0;
__pipe_lock(pipe);
@@ -344,9 +298,9 @@
int curbuf = pipe->curbuf;
struct pipe_buffer *buf = pipe->bufs + curbuf;
const struct pipe_buf_operations *ops = buf->ops;
- void *addr;
size_t chars = buf->len;
- int error, atomic;
+ size_t written;
+ int error;
if (chars > total_len)
chars = total_len;
@@ -358,27 +312,10 @@
break;
}
- atomic = !iov_fault_in_pages_write(iov, chars);
-redo:
- if (atomic)
- addr = kmap_atomic(buf->page);
- else
- addr = kmap(buf->page);
- error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars, atomic);
- if (atomic)
- kunmap_atomic(addr);
- else
- kunmap(buf->page);
- if (unlikely(error)) {
- /*
- * Just retry with the slow path if we failed.
- */
- if (atomic) {
- atomic = 0;
- goto redo;
- }
+ written = copy_page_to_iter(buf->page, buf->offset, chars, &iter);
+ if (unlikely(written < chars)) {
if (!ret)
- ret = error;
+ ret = -EFAULT;
break;
}
ret += chars;
