new helper: copy_page_from_iter()
parallel to copy_page_to_iter(). pipe_write() switched to it (and became
->write_iter()).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/pipe.c b/fs/pipe.c
index 05ccb00..21981e5 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -116,50 +116,6 @@
pipe_lock(pipe);
}
-static int
-pipe_iov_copy_from_user(void *to, struct iovec *iov, 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_from_user_inatomic(to, iov->iov_base, copy))
- return -EFAULT;
- } else {
- if (copy_from_user(to, iov->iov_base, copy))
- return -EFAULT;
- }
- to += copy;
- len -= copy;
- iov->iov_base += copy;
- iov->iov_len -= copy;
- }
- return 0;
-}
-
-/*
- * Pre-fault in the user memory, so we can use atomic copies.
- */
-static void iov_fault_in_pages_read(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);
- fault_in_pages_readable(iov->iov_base, this_len);
- len -= this_len;
- iov++;
- }
-}
-
static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
@@ -380,24 +336,19 @@
}
static ssize_t
-pipe_write(struct kiocb *iocb, const struct iovec *_iov,
- unsigned long nr_segs, loff_t ppos)
+pipe_write(struct kiocb *iocb, struct iov_iter *from)
{
struct file *filp = iocb->ki_filp;
struct pipe_inode_info *pipe = filp->private_data;
- ssize_t ret;
- int do_wakeup;
- struct iovec *iov = (struct iovec *)_iov;
- size_t total_len;
+ ssize_t ret = 0;
+ int do_wakeup = 0;
+ size_t total_len = iov_iter_count(from);
ssize_t chars;
- total_len = iov_length(iov, nr_segs);
/* Null write succeeds. */
if (unlikely(total_len == 0))
return 0;
- do_wakeup = 0;
- ret = 0;
__pipe_lock(pipe);
if (!pipe->readers) {
@@ -416,38 +367,19 @@
int offset = buf->offset + buf->len;
if (ops->can_merge && offset + chars <= PAGE_SIZE) {
- int error, atomic = 1;
- void *addr;
-
- error = ops->confirm(pipe, buf);
+ int error = ops->confirm(pipe, buf);
if (error)
goto out;
- iov_fault_in_pages_read(iov, chars);
-redo1:
- if (atomic)
- addr = kmap_atomic(buf->page);
- else
- addr = kmap(buf->page);
- error = pipe_iov_copy_from_user(offset + addr, iov,
- chars, atomic);
- if (atomic)
- kunmap_atomic(addr);
- else
- kunmap(buf->page);
- ret = error;
- do_wakeup = 1;
- if (error) {
- if (atomic) {
- atomic = 0;
- goto redo1;
- }
+ ret = copy_page_from_iter(buf->page, offset, chars, from);
+ if (unlikely(ret < chars)) {
+ error = -EFAULT;
goto out;
}
+ do_wakeup = 1;
buf->len += chars;
- total_len -= chars;
ret = chars;
- if (!total_len)
+ if (!iov_iter_count(from))
goto out;
}
}
@@ -466,8 +398,7 @@
int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1);
struct pipe_buffer *buf = pipe->bufs + newbuf;
struct page *page = pipe->tmp_page;
- char *src;
- int error, atomic = 1;
+ int copied;
if (!page) {
page = alloc_page(GFP_HIGHUSER);
@@ -483,40 +414,19 @@
* FIXME! Is this really true?
*/
do_wakeup = 1;
- chars = PAGE_SIZE;
- if (chars > total_len)
- chars = total_len;
-
- iov_fault_in_pages_read(iov, chars);
-redo2:
- if (atomic)
- src = kmap_atomic(page);
- else
- src = kmap(page);
-
- error = pipe_iov_copy_from_user(src, iov, chars,
- atomic);
- if (atomic)
- kunmap_atomic(src);
- else
- kunmap(page);
-
- if (unlikely(error)) {
- if (atomic) {
- atomic = 0;
- goto redo2;
- }
+ copied = copy_page_from_iter(page, 0, PAGE_SIZE, from);
+ if (unlikely(copied < PAGE_SIZE && iov_iter_count(from))) {
if (!ret)
- ret = error;
+ ret = -EFAULT;
break;
}
- ret += chars;
+ ret += copied;
/* Insert it into the buffer array */
buf->page = page;
buf->ops = &anon_pipe_buf_ops;
buf->offset = 0;
- buf->len = chars;
+ buf->len = copied;
buf->flags = 0;
if (is_packetized(filp)) {
buf->ops = &packet_pipe_buf_ops;
@@ -525,8 +435,7 @@
pipe->nrbufs = ++bufs;
pipe->tmp_page = NULL;
- total_len -= chars;
- if (!total_len)
+ if (!iov_iter_count(from))
break;
}
if (bufs < pipe->buffers)
@@ -1040,8 +949,8 @@
.llseek = no_llseek,
.read = new_sync_read,
.read_iter = pipe_read,
- .write = do_sync_write,
- .aio_write = pipe_write,
+ .write = new_sync_write,
+ .write_iter = pipe_write,
.poll = pipe_poll,
.unlocked_ioctl = pipe_ioctl,
.release = pipe_release,