1. 10 Apr, 2009 3 commits
    • Lai Jiangshan's avatar
      tracing: update file->f_pos when splice(2) it · c7625a55
      Lai Jiangshan authored
      
      
      Impact: Cleanup
      
      These two lines:
      
      	if (unlikely(*ppos))
      		return -ESPIPE;
      
      in tracing_buffers_splice_read() are not needed, VFS layer
      has disabled seek(2).
      
      We remove these two lines, and then we can update file->f_pos.
      
      And tracing_buffers_read() updates file->f_pos, this fix
      make tracing_buffers_splice_read() updates file->f_pos too.
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      LKML-Reference: <49D46670.4010503@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c7625a55
    • Lai Jiangshan's avatar
      tracing: allocate page when needed · ddd538f3
      Lai Jiangshan authored
      
      
      Impact: Cleanup
      
      Sometimes, we open trace_pipe_raw, but we don't read(2) it,
      we just splice(2) it, thus, the page is not used.
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      LKML-Reference: <49D4666B.4010608@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ddd538f3
    • Lai Jiangshan's avatar
      tracing: disable seeking for trace_pipe_raw · d1e7e02f
      Lai Jiangshan authored
      
      
      Impact: disable pread()
      
      We set tracing_buffers_fops.llseek to no_llseek,
      but we can still perform pread() to read this file.
      
      That is not expected.
      
      This fix uses nonseekable_open() to disable it.
      
      tracing_buffers_fops.llseek is still set to no_llseek,
      it mark this file is a "non-seekable device" and is used by
      sys_splice(). See also do_splice() or manual of splice(2):
      
      ERRORS
             EINVAL Target file system doesn't support  splicing;
                    neither  of the descriptors refers to a pipe;
                    or offset given for non-seekable device.
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      LKML-Reference: <49D46668.8030806@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d1e7e02f
  2. 09 Apr, 2009 11 commits
  3. 08 Apr, 2009 26 commits