On Mon 01-11-10 17:15:28, Tejun Heo wrote: > Over time, block layer has accumulated a set of APIs dealing with bdev > open, close, claim and release. > > * blkdev_get/put() are the primary open and close functions. > > * bd_claim/release() deal with exclusive open. > > * open/close_bdev_exclusive() are combination of open and claim and > the other way around, respectively. > > * bd_link/unlink_disk_holder() to create and remove holder/slave > symlinks. > > * open_by_devnum() wraps bdget() + blkdev_get(). > > The interface is a bit confusing and the decoupling of open and claim > makes it impossible to properly guarantee exclusive access as > in-kernel open + claim sequence can disturb the existing exclusive > open even before the block layer knows the current open if for another > exclusive access. Reorganize the interface such that, ... The patch looks OK to me as far as ext3, ext4, and reiserfs are concerned. One thing I wondered about when I looked at it - does someone use the 'mode' argument of the blkdev_put() function (well, apart from the exclusive flag)? Because I've looked at a few random disk ->release() functions and none of them used it... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
