diff options
Diffstat (limited to '')
-rw-r--r-- | fs/pipe.c | 133 |
1 files changed, 16 insertions, 117 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 78fd0d0788db..034bffac3f97 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -142,55 +142,6 @@ pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len, 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. */ @@ -226,52 +177,6 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, } /** - * generic_pipe_buf_map - virtually map a pipe buffer - * @pipe: the pipe that the buffer belongs to - * @buf: the buffer that should be mapped - * @atomic: whether to use an atomic map - * - * Description: - * This function returns a kernel virtual address mapping for the - * pipe_buffer passed in @buf. If @atomic is set, an atomic map is provided - * and the caller has to be careful not to fault before calling - * the unmap function. - * - * Note that this function calls kmap_atomic() if @atomic != 0. - */ -void *generic_pipe_buf_map(struct pipe_inode_info *pipe, - struct pipe_buffer *buf, int atomic) -{ - if (atomic) { - buf->flags |= PIPE_BUF_FLAG_ATOMIC; - return kmap_atomic(buf->page); - } - - return kmap(buf->page); -} -EXPORT_SYMBOL(generic_pipe_buf_map); - -/** - * generic_pipe_buf_unmap - unmap a previously mapped pipe buffer - * @pipe: the pipe that the buffer belongs to - * @buf: the buffer that should be unmapped - * @map_data: the data that the mapping function returned - * - * Description: - * This function undoes the mapping that ->map() provided. - */ -void generic_pipe_buf_unmap(struct pipe_inode_info *pipe, - struct pipe_buffer *buf, void *map_data) -{ - if (buf->flags & PIPE_BUF_FLAG_ATOMIC) { - buf->flags &= ~PIPE_BUF_FLAG_ATOMIC; - kunmap_atomic(map_data); - } else - kunmap(buf->page); -} -EXPORT_SYMBOL(generic_pipe_buf_unmap); - -/** * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer * @pipe: the pipe that the buffer belongs to * @buf: the buffer to attempt to steal @@ -351,8 +256,6 @@ EXPORT_SYMBOL(generic_pipe_buf_release); static const struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, - .map = generic_pipe_buf_map, - .unmap = generic_pipe_buf_unmap, .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, .steal = generic_pipe_buf_steal, @@ -361,8 +264,6 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = { static const struct pipe_buf_operations packet_pipe_buf_ops = { .can_merge = 0, - .map = generic_pipe_buf_map, - .unmap = generic_pipe_buf_unmap, .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, .steal = generic_pipe_buf_steal, @@ -379,12 +280,15 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, 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); @@ -394,9 +298,9 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, 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; @@ -408,21 +312,10 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, break; } - atomic = !iov_fault_in_pages_write(iov, chars); -redo: - addr = ops->map(pipe, buf, atomic); - error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars, atomic); - ops->unmap(pipe, buf, addr); - 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; @@ -538,10 +431,16 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, iov_fault_in_pages_read(iov, chars); redo1: - addr = ops->map(pipe, buf, atomic); + if (atomic) + addr = kmap_atomic(buf->page); + else + addr = kmap(buf->page); error = pipe_iov_copy_from_user(offset + addr, iov, chars, atomic); - ops->unmap(pipe, buf, addr); + if (atomic) + kunmap_atomic(addr); + else + kunmap(buf->page); ret = error; do_wakeup = 1; if (error) { |