1. 11 Jun, 2009 9 commits
  2. 10 Jun, 2009 29 commits
  3. 09 Jun, 2009 2 commits
    • Jan Kara's avatar
      jbd: fix race in buffer processing in commit code · a61d90d7
      Jan Kara authored
      In commit code, we scan buffers attached to a transaction.  During this
      scan, we sometimes have to drop j_list_lock and then we recheck whether
      the journal buffer head didn't get freed by journal_try_to_free_buffers().
       But checking for buffer_jbd(bh) isn't enough because a new journal head
      could get attached to our buffer head.  So add a check whether the journal
      head remained the same and whether it's still at the same transaction and
      list.
      
      This is a nasty bug and can cause problems like memory corruption (use after
      free) or trigger various assertions in JBD code (observed).
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Cc: <stable@kernel.org>
      Cc: <linux-ext4@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a61d90d7
    • Ian Kent's avatar
      autofs4: remove hashed check in validate_wait() · 463aea1a
      Ian Kent authored
      The recent ->lookup() deadlock correction required the directory inode
      mutex to be dropped while waiting for expire completion.  We were
      concerned about side effects from this change and one has been identified.
      
      I saw several error messages.
      
      They cause autofs to become quite confused and don't really point to the
      actual problem.
      
      Things like:
      
      handle_packet_missing_direct:1376: can't find map entry for (43,1827932)
      
      which is usually totally fatal (although in this case it wouldn't be
      except that I treat is as such because it normally is).
      
      do_mount_direct: direct trigger not valid or already mounted
      /test/nested/g3c/s1/ss1
      
      which is recoverable, however if this problem is at play it can cause
      autofs to become quite confused as to the dependencies in the mount tree
      because mount triggers end up mounted multiple times.  It's hard to
      accurately check for this over mounting case and automount shouldn't need
      to if the kernel module is doing its job.
      
      There was one other message, similar in consequence of this last one but I
      can't locate a log example just now.
      
      When checking if a mount has already completed prior to adding a new mount
      request to the wait queue we check if the dentry is hashed and, if so, if
      it is a mount point.  But, if a mount successfully completed while we
      slept on the wait queue mutex the dentry must exist for the mount to have
      completed so the test is not really needed.
      
      Mounts can also be done on top of a global root dentry, so for the above
      case, where a mount request completes and the wait queue entry has already
      been removed, the hashed test returning false can cause an incorrect
      callback to the daemon.  Also, d_mountpoint() is not sufficient to check
      if a mount has completed for the multi-mount case when we don't have a
      real mount at the base of the tree.
      Signed-off-by: default avatarIan Kent <raven@themaw.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      463aea1a