Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...

[pandora-kernel.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 4384c92..109a102 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -15,6 +15,7 @@
 #include <linux/pipe_fs_i.h>
 #include <linux/uio.h>
 #include <linux/highmem.h>
+#include <linux/pagemap.h>
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
@@ -94,11 +95,20 @@ static void anon_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buff
 {
        struct page *page = buf->page;
 
-       if (info->tmp_page) {
-               __free_page(page);
+       /*
+        * If nobody else uses this page, and we don't already have a
+        * temporary page, let's keep track of it as a one-deep
+        * allocation cache
+        */
+       if (page_count(page) == 1 && !info->tmp_page) {
+               info->tmp_page = page;
                return;
        }
-       info->tmp_page = page;
+
+       /*
+        * Otherwise just release our reference to it
+        */
+       page_cache_release(page);
 }
 
 static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *info, struct pipe_buffer *buf)
@@ -111,11 +121,19 @@ static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer
        kunmap(buf->page);
 }
 
+static int anon_pipe_buf_steal(struct pipe_inode_info *info,
+                              struct pipe_buffer *buf)
+{
+       buf->stolen = 1;
+       return 0;
+}
+
 static struct pipe_buf_operations anon_pipe_buf_ops = {
        .can_merge = 1,
        .map = anon_pipe_buf_map,
        .unmap = anon_pipe_buf_unmap,
        .release = anon_pipe_buf_release,
+       .steal = anon_pipe_buf_steal,
 };
 
 static ssize_t
@@ -152,6 +170,11 @@ pipe_readv(struct file *filp, const struct iovec *_iov,
                                chars = total_len;
 
                        addr = ops->map(filp, info, buf);
+                       if (IS_ERR(addr)) {
+                               if (!ret)
+                                       ret = PTR_ERR(addr);
+                               break;
+                       }
                        error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars);
                        ops->unmap(info, buf);
                        if (unlikely(error)) {
@@ -254,8 +277,16 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
                struct pipe_buf_operations *ops = buf->ops;
                int offset = buf->offset + buf->len;
                if (ops->can_merge && offset + chars <= PAGE_SIZE) {
-                       void *addr = ops->map(filp, info, buf);
-                       int error = pipe_iov_copy_from_user(offset + addr, iov, chars);
+                       void *addr;
+                       int error;
+
+                       addr = ops->map(filp, info, buf);
+                       if (IS_ERR(addr)) {
+                               error = PTR_ERR(addr);
+                               goto out;
+                       }
+                       error = pipe_iov_copy_from_user(offset + addr, iov,
+                                                       chars);
                        ops->unmap(info, buf);
                        ret = error;
                        do_wakeup = 1;
@@ -568,7 +599,7 @@ pipe_rdwr_open(struct inode *inode, struct file *filp)
  * The file_operations structs are not static because they
  * are also used in linux/fs/fifo.c to do operations on FIFOs.
  */
-struct file_operations read_fifo_fops = {
+const struct file_operations read_fifo_fops = {
        .llseek         = no_llseek,
        .read           = pipe_read,
        .readv          = pipe_readv,
@@ -580,7 +611,7 @@ struct file_operations read_fifo_fops = {
        .fasync         = pipe_read_fasync,
 };
 
-struct file_operations write_fifo_fops = {
+const struct file_operations write_fifo_fops = {
        .llseek         = no_llseek,
        .read           = bad_pipe_r,
        .write          = pipe_write,
@@ -592,7 +623,7 @@ struct file_operations write_fifo_fops = {
        .fasync         = pipe_write_fasync,
 };
 
-struct file_operations rdwr_fifo_fops = {
+const struct file_operations rdwr_fifo_fops = {
        .llseek         = no_llseek,
        .read           = pipe_read,
        .readv          = pipe_readv,