1. 01 Sep, 2008 1 commit
    • NeilBrown's avatar
      Remove invalidate_partition call from do_md_stop. · 271f5a9b
      NeilBrown authored
      When stopping an md array, or just switching to read-only, we
      currently call invalidate_partition while holding the mddev lock.
      The main reason for this is probably to ensure all dirty buffers
      are flushed (invalidate_partition calls fsync_bdev).
      
      However if any dirty buffers are found, it will almost certainly cause
      a deadlock as starting writeout will require an update to the
      superblock, and performing that updates requires taking the mddev
      lock - which is already held.
      
      This deadlock can be demonstrated by running "reboot -f -n" with
      a root filesystem on md/raid, and some dirty buffers in memory.
      
      All other calls to stop an array should already happen after a flush.
      The normal sequence is to stop using the array (e.g. umount) which
      will cause __blkdev_put to call sync_blockdev.  Then open the
      array and issue the STOP_ARRAY ioctl while the buffers are all still
      clean.
      
      So this invalidate_partition is normally a no-op, except for one case
      where it will cause a deadlock.
      
      So remove it.
      
      This patch possibly addresses the regression recored in
         http://bugzilla.kernel.org/show_bug.cgi?id=11460
      and
         http://bugzilla.kernel.org/show_bug.cgi?id=11452
      
      though it isn't yet clear how it ever worked.
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      271f5a9b
  2. 30 Aug, 2008 1 commit
  3. 29 Aug, 2008 4 commits
  4. 28 Aug, 2008 17 commits
  5. 27 Aug, 2008 17 commits