openrisc: add support for folded p4d page tables

[platform/kernel/linux-rpi.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 16fb72e..c7c4fb5 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -140,21 +140,20 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
                put_page(page);
 }
 
-static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
-                              struct pipe_buffer *buf)
+static bool anon_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+               struct pipe_buffer *buf)
 {
        struct page *page = buf->page;
 
-       if (page_count(page) == 1) {
-               memcg_kmem_uncharge_page(page, 0);
-               __SetPageLocked(page);
-               return 0;
-       }
-       return 1;
+       if (page_count(page) != 1)
+               return false;
+       memcg_kmem_uncharge_page(page, 0);
+       __SetPageLocked(page);
+       return true;
 }
 
 /**
- * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer
+ * generic_pipe_buf_try_steal - attempt to take ownership of a &pipe_buffer
  * @pipe:      the pipe that the buffer belongs to
  * @buf:       the buffer to attempt to steal
  *
@@ -165,8 +164,8 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
  *     he wishes; the typical use is insertion into a different file
  *     page cache.
  */
-int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
-                          struct pipe_buffer *buf)
+bool generic_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+               struct pipe_buffer *buf)
 {
        struct page *page = buf->page;
 
@@ -177,12 +176,11 @@ int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
         */
        if (page_count(page) == 1) {
                lock_page(page);
-               return 0;
+               return true;
        }
-
-       return 1;
+       return false;
 }
-EXPORT_SYMBOL(generic_pipe_buf_steal);
+EXPORT_SYMBOL(generic_pipe_buf_try_steal);
 
 /**
  * generic_pipe_buf_get - get a reference to a &struct pipe_buffer
@@ -201,22 +199,6 @@ bool generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
 EXPORT_SYMBOL(generic_pipe_buf_get);
 
 /**
- * generic_pipe_buf_confirm - verify contents of the pipe buffer
- * @info:      the pipe that the buffer belongs to
- * @buf:       the buffer to confirm
- *
- * Description:
- *     This function does nothing, because the generic pipe code uses
- *     pages that are always good when inserted into the pipe.
- */
-int generic_pipe_buf_confirm(struct pipe_inode_info *info,
-                            struct pipe_buffer *buf)
-{
-       return 0;
-}
-EXPORT_SYMBOL(generic_pipe_buf_confirm);
-
-/**
  * generic_pipe_buf_release - put a reference to a &struct pipe_buffer
  * @pipe:      the pipe that the buffer belongs to
  * @buf:       the buffer to put a reference to
@@ -231,48 +213,12 @@ void generic_pipe_buf_release(struct pipe_inode_info *pipe,
 }
 EXPORT_SYMBOL(generic_pipe_buf_release);
 
-/* New data written to a pipe may be appended to a buffer with this type. */
 static const struct pipe_buf_operations anon_pipe_buf_ops = {
-       .confirm = generic_pipe_buf_confirm,
-       .release = anon_pipe_buf_release,
-       .steal = anon_pipe_buf_steal,
-       .get = generic_pipe_buf_get,
-};
-
-static const struct pipe_buf_operations anon_pipe_buf_nomerge_ops = {
-       .confirm = generic_pipe_buf_confirm,
-       .release = anon_pipe_buf_release,
-       .steal = anon_pipe_buf_steal,
-       .get = generic_pipe_buf_get,
-};
-
-static const struct pipe_buf_operations packet_pipe_buf_ops = {
-       .confirm = generic_pipe_buf_confirm,
-       .release = anon_pipe_buf_release,
-       .steal = anon_pipe_buf_steal,
-       .get = generic_pipe_buf_get,
+       .release        = anon_pipe_buf_release,
+       .try_steal      = anon_pipe_buf_try_steal,
+       .get            = generic_pipe_buf_get,
 };
 
-/**
- * pipe_buf_mark_unmergeable - mark a &struct pipe_buffer as unmergeable
- * @buf:       the buffer to mark
- *
- * Description:
- *     This function ensures that no future writes will be merged into the
- *     given &struct pipe_buffer. This is necessary when multiple pipe buffers
- *     share the same backing page.
- */
-void pipe_buf_mark_unmergeable(struct pipe_buffer *buf)
-{
-       if (buf->ops == &anon_pipe_buf_ops)
-               buf->ops = &anon_pipe_buf_nomerge_ops;
-}
-
-static bool pipe_buf_can_merge(struct pipe_buffer *buf)
-{
-       return buf->ops == &anon_pipe_buf_ops;
-}
-
 /* Done while waiting without holding the pipe lock - thus the READ_ONCE() */
 static inline bool pipe_readable(const struct pipe_inode_info *pipe)
 {
@@ -478,7 +424,8 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
                struct pipe_buffer *buf = &pipe->bufs[(head - 1) & mask];
                int offset = buf->offset + buf->len;
 
-               if (pipe_buf_can_merge(buf) && offset + chars <= PAGE_SIZE) {
+               if ((buf->flags & PIPE_BUF_FLAG_CAN_MERGE) &&
+                   offset + chars <= PAGE_SIZE) {
                        ret = pipe_buf_confirm(pipe, buf);
                        if (ret)
                                goto out;
@@ -541,11 +488,10 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
                        buf->ops = &anon_pipe_buf_ops;
                        buf->offset = 0;
                        buf->len = 0;
-                       buf->flags = 0;
-                       if (is_packetized(filp)) {
-                               buf->ops = &packet_pipe_buf_ops;
+                       if (is_packetized(filp))
                                buf->flags = PIPE_BUF_FLAG_PACKET;
-                       }
+                       else
+                               buf->flags = PIPE_BUF_FLAG_CAN_MERGE;
                        pipe->tmp_page = NULL;
 
                        copied = copy_page_from_iter(page, 0, PAGE_SIZE, from);