On Fri, Nov 20, 2020 at 04:32:53PM +0100, Christoph Hellwig wrote: > On Fri, Nov 20, 2020 at 12:21:21PM +0100, Jan Kara wrote: > > > > AFAICT bd_size_lock is pointless after these changes so we can just remove > > > > it? > > > > > > I don't think it is, as reuqiring bd_mutex for size updates leads to > > > rather awkward lock ordering problems. > > > > OK, let me ask differently: What is bd_size_lock protecting now? Ah, I see, > > on 32-bit it is needed to prevent torn writes to i_size, right? > > Exactly. In theory we could skip it for 64-bit, but as updating the > size isn't a fast path, and struct block_device isn't super size critical > I'd rather keep the same code for 32 vs 64-bit builds. Is it better to switch to i_size_write() / i_size_read()?
