On Fri, Jul 05, 2024 at 08:06:51AM +1000, Dave Chinner wrote: > > > It seems strange to silently clamp these? Presumably for the bs>ps usecase, > > > whatever values are passed in are a hard requirement? So wouldn't want them to > > > be silently reduced. (Especially given the recent change to reduce the size of > > > MAX_PAGECACHE_ORDER to less then PMD size in some cases). > > > > Hm, yes. We should probably make this return an errno. Including > > returning an errno for !IS_ENABLED() and min > 0. > > What are callers supposed to do with an error? In the case of > setting up a newly allocated inode in XFS, the error would be > returned in the middle of a transaction and so this failure would > result in a filesystem shutdown. I suggest you handle it better than this. If the device is asking for a blocksize > PMD_SIZE, you should fail to mount it. If the device is asking for a blocksize > PAGE_SIZE and CONFIG_TRANSPARENT_HUGEPAGE is not set, you should also decline to mount the filesystem.