1. 13 2月, 2013 3 次提交
  2. 09 12月, 2012 1 次提交
    • J
      cifs: simplify id_to_sid and sid_to_id mapping code · faa65f07
      Jeff Layton 提交于
      The cifs.idmap handling code currently causes the kernel to cache the
      data from userspace twice. It first looks in a rbtree to see if there is
      a matching entry for the given id. If there isn't then it calls
      request_key which then checks its cache and then calls out to userland
      if it doesn't have one. If the userland program establishes a mapping
      and downcalls with that info, it then gets cached in the keyring and in
      this rbtree.
      
      Aside from the double memory usage and the performance penalty in doing
      all of these extra copies, there are some nasty bugs in here too. The
      code declares four rbtrees and spinlocks to protect them, but only seems
      to use two of them. The upshot is that the same tree is used to hold
      (eg) uid:sid and sid:uid mappings. The comparitors aren't equipped to
      deal with that.
      
      I think we'd be best off to remove a layer of caching in this code. If
      this was originally done for performance reasons, then that really seems
      like a premature optimization.
      
      This patch does that -- it removes the rbtrees and the locks that
      protect them and simply has the code do a request_key call on each call
      into sid_to_id and id_to_sid. This greatly simplifies this code and
      should roughly halve the memory utilization from using the idmapping
      code.
      Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
      Signed-off-by: NJeff Layton <jlayton@redhat.com>
      Signed-off-by: NSteve French <smfrench@gmail.com>
      faa65f07
  3. 08 12月, 2012 1 次提交
  4. 06 12月, 2012 2 次提交
  5. 29 9月, 2012 1 次提交
  6. 25 9月, 2012 18 次提交
  7. 28 7月, 2012 3 次提交
  8. 25 7月, 2012 6 次提交
  9. 24 7月, 2012 5 次提交