#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>
*/
/* Drop the inode semaphore and wait for a pipe event, atomically */
-void pipe_wait(struct inode * inode)
+void pipe_wait(struct pipe_inode_info *pipe)
{
DEFINE_WAIT(wait);
* Pipes are system-local resources, so sleeping on them
* is considered a noninteractive wait:
*/
- prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
- mutex_unlock(PIPE_MUTEX(*inode));
+ prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
+ if (pipe->inode)
+ mutex_unlock(&pipe->inode->i_mutex);
schedule();
- finish_wait(PIPE_WAIT(*inode), &wait);
- mutex_lock(PIPE_MUTEX(*inode));
+ finish_wait(&pipe->wait, &wait);
+ if (pipe->inode)
+ mutex_lock(&pipe->inode->i_mutex);
}
static int
{
struct page *page = buf->page;
- if (info->tmp_page) {
- __free_page(page);
+ buf->flags &= ~PIPE_BUF_FLAG_STOLEN;
+
+ /*
+ * 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)
kunmap(buf->page);
}
+static int anon_pipe_buf_steal(struct pipe_inode_info *info,
+ struct pipe_buffer *buf)
+{
+ buf->flags |= PIPE_BUF_FLAG_STOLEN;
+ 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
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)) {
wake_up_interruptible_sync(PIPE_WAIT(*inode));
kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);
}
- pipe_wait(inode);
+ pipe_wait(inode->i_pipe);
}
mutex_unlock(PIPE_MUTEX(*inode));
/* Signal writers asynchronously that there is more room. */
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;
do_wakeup = 0;
}
PIPE_WAITING_WRITERS(*inode)++;
- pipe_wait(inode);
+ pipe_wait(inode->i_pipe);
PIPE_WAITING_WRITERS(*inode)--;
}
out:
* 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,
.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,
.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,
.fasync = pipe_rdwr_fasync,
};
+struct pipe_inode_info * alloc_pipe_info(struct inode *inode)
+{
+ struct pipe_inode_info *info;
+
+ info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
+ if (info) {
+ init_waitqueue_head(&info->wait);
+ info->r_counter = info->w_counter = 1;
+ info->inode = inode;
+ }
+
+ return info;
+}
+
void free_pipe_info(struct inode *inode)
{
int i;
kfree(info);
}
-struct inode* pipe_new(struct inode* inode)
-{
- struct pipe_inode_info *info;
-
- info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
- if (!info)
- goto fail_page;
- inode->i_pipe = info;
-
- init_waitqueue_head(PIPE_WAIT(*inode));
- PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1;
-
- return inode;
-fail_page:
- return NULL;
-}
-
-static struct vfsmount *pipe_mnt;
+static struct vfsmount *pipe_mnt __read_mostly;
static int pipefs_delete_dentry(struct dentry *dentry)
{
return 1;
if (!inode)
goto fail_inode;
- if(!pipe_new(inode))
+ inode->i_pipe = alloc_pipe_info(inode);
+ if (!inode->i_pipe)
goto fail_iput;
+
PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1;
inode->i_fop = &rdwr_pipe_fops;