task IO accounting: provide distinct tgid/tid I/O statistics

[sfrench/cifs-2.6.git] / fs / sync.c

diff --git a/fs/sync.c b/fs/sync.c
index 2f97576355b8828e2b952782860e5af7b3bebea2..2967562d416fb52e54a1af5840d0dc63c0d25cfb 100644 (file)
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -64,7 +64,7 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
        /* sync the superblock to buffers */
        sb = inode->i_sb;
        lock_super(sb);
-       if (sb->s_op->write_super)
+       if (sb->s_dirt && sb->s_op->write_super)
                sb->s_op->write_super(sb);
        unlock_super(sb);
 
@@ -139,7 +139,8 @@ asmlinkage long sys_fdatasync(unsigned int fd)
  * before performing the write.
  *
  * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
- * range which are not presently under writeback.
+ * range which are not presently under writeback. Note that this may block for
+ * significant periods due to exhaustion of disk request structures.
  *
  * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
  * after performing the write.
@@ -236,6 +237,14 @@ out:
        return ret;
 }
 
+/* It would be nice if people remember that not all the world's an i386
+   when they introduce new system calls */
+asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
+                                    loff_t offset, loff_t nbytes)
+{
+       return sys_sync_file_range(fd, offset, nbytes, flags);
+}
+
 /*
  * `endbyte' is inclusive
  */