Christoph Hellwig writes: > On Sat, Oct 18, 2014 at 07:21:26PM +0400, Dmitry Monakhov wrote: >> sys_fadvise result in direct f_mode modification, which may be not >> suitable for some unusual filesytems where file mode invariant is more >> complex. In order to support such filesystems we have to delegate fadvise >> logic to filesystem layer. > > Is there a real use case for it? So for it seems mostly about ecryptfs, > and even that use is lacking a proper explanation. Fairly to say original issue was with vzfs (COW stack filesystem for containers from openvz). As far as I understand direct analog is unionfs. We asserted v_file->mode == lower_file->f_mode, but fadvise (POSIX_FADV_{RANDOM,RANDOM,SEQUENTIAL})changes v_file->mode directly. > > Also fadvice and set_flags seem entirely unrelated, I don't understand > why you're throwing fadvice in thise series. It has semantic relation. Both methods manipulate filp->XXX internals directly No problem I can split this to separate patch set. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html