On Tue, Jan 29, 2019 at 9:17 AM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > On Mon, Jan 28, 2019 at 11:14 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > > > On Mon, Jan 28, 2019 at 11:22 PM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > > > > > On Mon, Jan 28, 2019 at 10:17 PM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > > > > > > Trying to put some code together... > > > > > > Very rudimentary patch attached. It doens't do direct IO yet, but > > > demonstrates what I meant about achoring the upper file in the inode. > > > > > > > Code looks good, but blows up on xfstests, so I'll wait for a baked patch > > before testing. > > > > > Also found the trick to actually make writeback work: > > > super_setup_bdi() call in fill_super... > > > > > > > Cool, but when adding only setup_bdi() this to my code, I still don't see any > > writeback. No writeback observed with your patch as well. > > I did observe writeback, but haven't done much testing. Will > hopefully get this into a better shape today. > OK, I see the writebacks. Didn't see them with test: # ./run --ov --samefs --recycle rename-new-pop-dir ... ./run --open-file /mnt/a/dir100-new/a -w -c -W aaaa [ 59.092942] ovl_write_end: page->flags: 10000000000000c ... /mnt/a/dir100-new/a: File size wrong (got 0, want 4) Missing sync_filesystem(sb) in ovl_remount()? No flush yet. What else? There is also a NULL pointer deference in ovl_fault() of file opened as upper with vfs_fadvise(NULL, ... Need to remove vfs_fadvise. Thanks, Amir.
