On Fri, Apr 10, 2015 at 02:28:16PM +0100, David Howells wrote: > Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > SEEK_HOLE/SEEK_DATA is what you want, as they are page cache > > coherent, not extent based operations. And, really if you need it to > > really be able to find real holes, then a superblock flag might be a > > better way of marking filesystems with the required capability. > > Actually, I wonder if what I want is a kernel_read() that returns ENODATA upon > encountering a hole at the beginning of the area to be read. NFS READ_PLUS could also make use of this, but someone needs to actually implement it. Until we have that lseek SEEK_HOLE/DATA is the way to go, and the horrible ->bmap hack needs to die ASAP, I can't believe you managed to sneak that in in the not too distant past. -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs
