1. 24 12月, 2008 1 次提交
    • W
      nfs: remove redundant tests on reading new pages · 136221fc
      Wu Fengguang 提交于
      aops->readpages() and its NFS helper readpage_async_filler() will only
      be called to do readahead I/O for newly allocated pages. So it's not
      necessary to test for the always 0 dirty/uptodate page flags.
      
      The removal of nfs_wb_page() call also fixes a readahead bug: the NFS
      readahead has been synchronous since 2.6.23, because that call will
      clear PG_readahead, which is the reminder for asynchronous readahead.
      
      More background: the PG_readahead page flag is shared with PG_reclaim,
      one for read path and the other for write path. clear_page_dirty_for_io()
      unconditionally clears PG_readahead to prevent possible readahead residuals,
      assuming itself to be always called in the write path. However, NFS is one
      and the only exception in that it _always_ calls clear_page_dirty_for_io()
      in the read path, i.e. for readpages()/readpage().
      
      Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
      Signed-off-by: NWu Fengguang <wfg@linux.intel.com>
      Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
      136221fc
  2. 21 12月, 2008 3 次提交
  3. 20 12月, 2008 10 次提交
  4. 19 12月, 2008 16 次提交
  5. 18 12月, 2008 10 次提交