Re: aufs_do_xino_fwrite() EINTR loop (WAS: aufs_destroy_inode() deadlock?)

[Akihiro Suda]

   Yes, I meant that generic_perform_write() simply returns EINTR every time
   when it is called.
   So do_xino_fwrite() cannot escape from the loop.
   Â  Â static ssize_t do_xino_fwrite(vfs_writef_t func, struct file *file,
   void *kbuf,
   Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  size_t size, loff_t *pos)
   Â  Â  {
   Â  Â  ..
   Â  Â  Â  Â  do {
   Â  Â  Â  Â  Â  Â  Â /* cannot escape from this loop */
   Â  Â  Â  Â  Â  Â  err = func(file, buf.u, size, pos);
   Â  Â  Â  Â  } while (err == -EAGAIN || err == -EINTR);
   Â  Â  ..
   Â  Â  }
   Sorry for my ambiguity.
   BTW, I tested your patch in my machine, and it seems working well.
   If modifying 296291cd is not accepted, your patch will be the best solution.
   Thanks!

   2015-12-25 15:16 GMT+09:00 <[1]sf...@users.sourceforge.net>:

     Akihiro Suda:
     > However, the bug is a regression caused by commit 296291cd ("mm: make
     > sendfile(2) killable") to the upstream of Linux kernel.
     > [2]https://github.com/torvalds/linux/commit/296291cd
     > This produces infinite -EINTR loop in
     mm/filemap.c:generic_perform_write().
     > Perhaps it can also affect filesystems other than AUFS.
     Why infinite?
     generic_perform_write() simply returns EINTR, doesn't it?
     J. R. Okajima

References

   1. mailto:sf...@users.sourceforge.net
   2. https://github.com/torvalds/linux/commit/296291cd

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