nilfs2: fix missing zero-fill initialization of btree node cache

[safe/jmp/linux-2.6] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 7aea8b8..52c4151 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -37,6 +37,42 @@
  * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09
  */
 
+static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass)
+{
+       if (pipe->inode)
+               mutex_lock_nested(&pipe->inode->i_mutex, subclass);
+}
+
+void pipe_lock(struct pipe_inode_info *pipe)
+{
+       /*
+        * pipe_lock() nests non-pipe inode locks (for writing to a file)
+        */
+       pipe_lock_nested(pipe, I_MUTEX_PARENT);
+}
+EXPORT_SYMBOL(pipe_lock);
+
+void pipe_unlock(struct pipe_inode_info *pipe)
+{
+       if (pipe->inode)
+               mutex_unlock(&pipe->inode->i_mutex);
+}
+EXPORT_SYMBOL(pipe_unlock);
+
+void pipe_double_lock(struct pipe_inode_info *pipe1,
+                     struct pipe_inode_info *pipe2)
+{
+       BUG_ON(pipe1 == pipe2);
+
+       if (pipe1 < pipe2) {
+               pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+               pipe_lock_nested(pipe2, I_MUTEX_CHILD);
+       } else {
+               pipe_lock_nested(pipe2, I_MUTEX_PARENT);
+               pipe_lock_nested(pipe1, I_MUTEX_CHILD);
+       }
+}
+
 /* Drop the inode semaphore and wait for a pipe event, atomically */
 void pipe_wait(struct pipe_inode_info *pipe)
 {
@@ -47,12 +83,10 @@ void pipe_wait(struct pipe_inode_info *pipe)
         * is considered a noninteractive wait:
         */
        prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
-       if (pipe->inode)
-               mutex_unlock(&pipe->inode->i_mutex);
+       pipe_unlock(pipe);
        schedule();
        finish_wait(&pipe->wait, &wait);
-       if (pipe->inode)
-               mutex_lock(&pipe->inode->i_mutex);
+       pipe_lock(pipe);
 }
 
 static int
@@ -268,6 +302,20 @@ int generic_pipe_buf_confirm(struct pipe_inode_info *info,
        return 0;
 }
 
+/**
+ * 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
+ *
+ * Description:
+ *     This function releases a reference to @buf.
+ */
+void generic_pipe_buf_release(struct pipe_inode_info *pipe,
+                             struct pipe_buffer *buf)
+{
+       page_cache_release(buf->page);
+}
+
 static const struct pipe_buf_operations anon_pipe_buf_ops = {
        .can_merge = 1,
        .map = generic_pipe_buf_map,
@@ -667,10 +715,7 @@ pipe_read_fasync(int fd, struct file *filp, int on)
        retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
        mutex_unlock(&inode->i_mutex);
 
-       if (retval < 0)
-               return retval;
-
-       return 0;
+       return retval;
 }
 
 
@@ -684,10 +729,7 @@ pipe_write_fasync(int fd, struct file *filp, int on)
        retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
        mutex_unlock(&inode->i_mutex);
 
-       if (retval < 0)
-               return retval;
-
-       return 0;
+       return retval;
 }
 
 
@@ -699,18 +741,14 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
        int retval;
 
        mutex_lock(&inode->i_mutex);
-
        retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
-
-       if (retval >= 0)
+       if (retval >= 0) {
                retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
-
+               if (retval < 0) /* this can happen only if on == T */
+                       fasync_helper(-1, filp, 0, &pipe->fasync_readers);
+       }
        mutex_unlock(&inode->i_mutex);
-
-       if (retval < 0)
-               return retval;
-
-       return 0;
+       return retval;
 }
 
 
@@ -870,7 +908,7 @@ static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
                                dentry->d_inode->i_ino);
 }
 
-static struct dentry_operations pipefs_dentry_operations = {
+static const struct dentry_operations pipefs_dentry_operations = {
        .d_delete       = pipefs_delete_dentry,
        .d_dname        = pipefs_dname,
 };
@@ -899,8 +937,8 @@ static struct inode * get_pipe_inode(void)
         */
        inode->i_state = I_DIRTY;
        inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR;
-       inode->i_uid = current->fsuid;
-       inode->i_gid = current->fsgid;
+       inode->i_uid = current_fsuid();
+       inode->i_gid = current_fsgid();
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 
        return inode;
@@ -1016,10 +1054,7 @@ int do_pipe_flags(int *fd, int flags)
                goto err_fdr;
        fdw = error;
 
-       error = audit_fd_pair(fdr, fdw);
-       if (error < 0)
-               goto err_fdw;
-
+       audit_fd_pair(fdr, fdw);
        fd_install(fdr, fr);
        fd_install(fdw, fw);
        fd[0] = fdr;
@@ -1027,8 +1062,6 @@ int do_pipe_flags(int *fd, int flags)
 
        return 0;
 
- err_fdw:
-       put_unused_fd(fdw);
  err_fdr:
        put_unused_fd(fdr);
  err_read_pipe:
@@ -1039,16 +1072,11 @@ int do_pipe_flags(int *fd, int flags)
        return error;
 }
 
-int do_pipe(int *fd)
-{
-       return do_pipe_flags(fd, 0);
-}
-
 /*
  * sys_pipe() is the normal C calling standard for creating
  * a pipe. It's not the way Unix traditionally does this, though.
  */
-asmlinkage long __weak sys_pipe2(int __user *fildes, int flags)
+SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags)
 {
        int fd[2];
        int error;
@@ -1064,7 +1092,7 @@ asmlinkage long __weak sys_pipe2(int __user *fildes, int flags)
        return error;
 }
 
-asmlinkage long __weak sys_pipe(int __user *fildes)
+SYSCALL_DEFINE1(pipe, int __user *, fildes)
 {
        return sys_pipe2(fildes, 0);
 }