On Mon 19-09-16 09:25:48, Dilger, Andreas wrote: > On Sep 19, 2016, at 09:28, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Sun, Sep 18, 2016 at 04:37:29PM -0400, James Simmons wrote: > >> + * Range lock is used to allow multiple threads writing a single shared > >> + * file given each thread is writing to a non-overlapping portion of the > >> + * file. > >> + * > >> + * Refer to the possible upstream kernel version of range lock by > >> + * Jan Kara <jack@xxxxxxx>: https://lkml.org/lkml/2013/1/31/480 > >> + * > >> + * This file could later replaced by the upstream kernel version. > > > > It doesn't look like range_lock ever got accepted in the kernel tree, > > any idea what happened to it? Having a per-filesystem lock type seems > > odd to me... > > I've added Jan and linux-fsdevel to the CC list to see what interest > there is in the range locking implementaion. At the time we added this > to Lustre it appeared that this was moving nicely torward landing, but > it seems to have stalled. > > I think the range locking implementation is fairly generic, and if there > are other users in the kernel it could easily be pulled out of the staging > dir into vfs/. I'm not against it going into vfs/ directly either, but > not sure whether that is acceptable if the only user is in staging. Yeah, so the problem with my range_lock implementation (and your one looks fairly similar from a quick look) is that it is fairly heavyweight. That may be OK for an inode_lock replacement but it needs a careful benchmarking. Davidlohr was looking into making the implementation more efficient (he wanted to use it for mmap_sem) but I think it got preempted by other work. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
