1. 26 Mar, 2009 2 commits
    • Boaz Harrosh's avatar
      block: WARN in __blk_put_request() for potential bio leak · 1cd96c24
      Boaz Harrosh authored
      Put a WARN_ON in __blk_put_request if it is about to
      leak bio(s). This is a serious bug that can happen in error
      handling code paths.
      For this to work I have fixed a couple of places in block/ where
      request->bio != NULL ownership was not honored. And a small cleanup
      at sg_io() while at it.
      Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
    • Nikanth Karthikesan's avatar
      loop: fix circular locking in loop_clr_fd() · f028f3b2
      Nikanth Karthikesan authored
      With CONFIG_PROVE_LOCKING enabled
      $ losetup /dev/loop0 file
      $ losetup -o 32256 /dev/loop1 /dev/loop0
      $ losetup -d /dev/loop1
      $ losetup -d /dev/loop0
      triggers a [ INFO: possible circular locking dependency detected ]
      I think this warning is a false positive.
      Open/close on a loop device acquires bd_mutex of the device before
      acquiring lo_ctl_mutex of the same device. For ioctl(LOOP_CLR_FD) after
      acquiring lo_ctl_mutex, fput on the backing_file might acquire the bd_mutex of
      a device, if backing file is a device and this is the last reference to the
      file being dropped . But it is guaranteed that it is impossible to have a
      circular list of backing devices.(say loop2->loop1->loop0->loop2 is not
      possible), which guarantees that this can never deadlock.
      So this warning should be suppressed. It is very difficult to annotate lockdep
      not to warn here in the correct way. A simple way to silence lockdep could be
      to mark the lo_ctl_mutex in ioctl to be a sub class, but this might mask some
      other real bugs.
      @@ -1164,7 +1164,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
       	struct loop_device *lo = bdev->bd_disk->private_data;
       	int err;
      -	mutex_lock(&lo->lo_ctl_mutex);
      +	mutex_lock_nested(&lo->lo_ctl_mutex, 1);
       	switch (cmd) {
       	case LOOP_SET_FD:
       		err = loop_set_fd(lo, mode, bdev, arg);
      Or actually marking the bd_mutex after lo_ctl_mutex as a sub class could be
      a better solution.
      Luckily it is easy to avoid calling fput on backing file with lo_ctl_mutex
      held, so no lockdep annotation is required.
      If you do not like the special handling of the lo_ctl_mutex just for the
      LOOP_CLR_FD ioctl in lo_ioctl(), the mutex handling could be moved inside
      each of the individual ioctl handlers and I could send you another patch.
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
  2. 24 Mar, 2009 11 commits
  3. 23 Mar, 2009 11 commits
  4. 22 Mar, 2009 6 commits
  5. 21 Mar, 2009 2 commits
  6. 20 Mar, 2009 5 commits
  7. 19 Mar, 2009 3 commits