From f0d1bec9d58d4c038d0ac958c9af82be6eb18045 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 3 Apr 2014 15:05:18 -0400 Subject: 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 --- fs/pipe.c | 129 +++++++++----------------------------------------------------- 1 file changed, 19 insertions(+), 110 deletions(-) (limited to 'fs/pipe.c') 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 @@ void pipe_wait(struct pipe_inode_info *pipe) 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 inline int is_packetized(struct file *file) } 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 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, 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 @@ redo1: 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 @@ redo1: * 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 @@ redo2: 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 @@ const struct file_operations pipefifo_fops = { .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, -- cgit v1.1