Messages in this thread |  | | | Date | Wed, 22 Sep 2010 19:21:11 -0400 | | From | Valerie Aurora <> | | Subject | Re: [PATCH 6/7 v3] overlay: hybrid overlay filesystem prototype |
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On Mon, Sep 20, 2010 at 08:04:10PM +0200, Miklos Szeredi wrote: > From: Miklos Szeredi <mszeredi@suse.cz> > > This overlay filesystem is a hybrid of entirely filesystem based > (unionfs, aufs) and entierly VFS based (union mounts) solutions.
[...]
> +static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) > +{ > + struct file *old_file; > + struct file *new_file; > + int error = 0; > + > + if (len == 0) > + return 0; > + > + old_file = path_open(old, O_RDONLY); > + if (IS_ERR(old_file)) > + return PTR_ERR(old_file); > + > + new_file = path_open(new, O_WRONLY); > + if (IS_ERR(new_file)) { > + error = PTR_ERR(new_file); > + goto out_fput; > + } > + > + /* FIXME: copy up sparse files efficiently */ > + while (len) { > + loff_t offset = new_file->f_pos; > + size_t this_len = OVL_COPY_UP_CHUNK_SIZE; > + long bytes; > + > + if (len < this_len) > + this_len = len; > + > + if (signal_pending_state(TASK_KILLABLE, current)) > + return -EINTR; > + > + bytes = do_splice_direct(old_file, &offset, new_file, this_len, > + SPLICE_F_MOVE);
Interruptible copyup is good. But it looks like splice setup is kind of heavyweight and we should do it as seldom as possible.
What about implementing splice flag SPLICE_F_INTERRUPTIBLE instead?
-VAL
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