On Mon, Apr 17, 2017 at 02:59:33AM +0300, Amir Goldstein wrote:
[..]
> @@ -272,6 +385,33 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
> goto out_put_upper;
> }
>
> + /* Try to lookup lower layers by file handle (at root) */
> + d.by_path = false;
> + for (i = 0; !d.stop && d.fh && i < roe->numlower; i++) {
> + struct path lowerpath = roe->lowerstack[i];
> +
> + d.last = i == roe->numlower - 1;
> + err = ovl_lookup_layer_fh(&lowerpath, &d, &this);
> + if (err)
> + goto out_put;
> +
> + if (!this)
> + continue;
> +
> + stack[ctr].dentry = this;
> + stack[ctr].mnt = lowerpath.mnt;
> + ctr++;
> + }
> +
> + /* Fallback to lookup lower layers by name (at parent) */
> + if (ctr) {
> + d.stop = true;
Hi Amir,
Got a very basic question. So say I two lower layers and a directory is
in present in both, say lower1/dir1 and lower2/dir1. Now this directory
gets copied up to upper/dir1. Assume lower1/dir1 is being copied up. So
upper/dir1 will save file handle of lower1/dir1 right? This file handle
does not represent lower2/dir1?
IOW, later when I am doing lookup, then using file handle I will find
dentry of lower1/dir1 but not lower2/dir1. And looks like we will not
path based lookup as ctr will be non-zero (as we found one dentry in
one path).
What am I missing.
(This ovl_lookup() logic has become really twisted now. I wished it was
little easier to read.)
Vivek
