On Thu, Mar 29, 2012 at 1:43 AM, Jan Kara <jack@xxxxxxx> wrote: > Most of places where we want freeze protection coincides with the places where > we also have remount-ro protection. So make mnt_want_write() and > mnt_drop_write() (and their _file alternative) prevent freezing as well. > For the few cases that are really interested only in remount-ro protection > provide new function variants. The underlying mechanism of mnt_want_write() and sb_start_write() is basically the same: - increment per-CPU counter - mb - check flag - retry loop for races It is scalable but still there is a non-zero overhead, and duplicating it doesn't seem to make a lot of sense. Why not instead try to use a common abstraction for both? Then the success case will be common, only the relatively rare failure case needs to be handled separately. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html