fs/overlayfs/export.c

39  * "layer N connected" ancestor and verifying that all parents along the way are
42  * making that ancestor "layer N connected". For example:
50  * in ovl_lookup_real_ancestor() will not be able to lookup a connected overlay
51  * dentry from the connected lower dentry /a/b/c.
55  * /a/b. After copy up (and index) of /a/b, it will become "layer 2 connected"
58  * a connected overlay dentry will be accomplished.
62  * layer 1. If that improvement is made, then the check for "layer N connected"
93  * @dentry is "connected" if all ancestors up to root or a "connected" ancestor
95  * copy up a "connectable" ancestor to make it "connected". A "connected" dentry
96  * cannot become non "connected", so cache positive result in dentry flags.
98  * Return the connected origin layer or < 0 on error.
133 		/* If @parent is connected or indexed we are done */
172  * (*) Decoding a connected overlay dir from real lower dentry is not always
209 	 * ovl_connect_layer() will try to make origin's layer "connected" by
344  * Lookup a child overlay dentry to get a connected overlay dentry whose real
349 static struct dentry *ovl_lookup_real_one(struct dentry *connected,
353 	struct inode *dir = d_inode(connected);
362 	 * connected overlay dir, we return -ECHILD and restart the lookup of
363 	 * connected real path from the top.
368 	if (ovl_dentry_real_at(connected, layer->idx) != parent)
383 	this = lookup_one_len(name.name.name, connected, name.name.len);
404 	pr_warn_ratelimited("failed to lookup one by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
405 			    real, layer->idx, connected, err);
448 	/* Get connected upper overlay dir from index */
461 		 * connected/hashed upper parent (or up to root).
531  * Lookup a connected overlay dentry whose real dentry is @real.
539 	struct dentry *connected;
542 	connected = ovl_lookup_real_ancestor(sb, real, layer);
543 	if (IS_ERR(connected))
544 		return connected;
549 		struct dentry *real_connected = ovl_dentry_real_at(connected,
555 		/* Find the topmost dentry not yet connected */
572 				dput(connected);
573 				connected = dget(sb->s_root);
593 			this = ovl_lookup_real_one(connected, next, layer);
599 			 * overlay rename of child away from 'connected' parent.
613 				dput(connected);
614 				connected = this;
625 	return connected;
628 	pr_warn_ratelimited("failed to lookup by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
629 			    real, layer->idx, connected, err);
630 	dput(connected);
658 	 * If real dentry is connected and hashed, get a connected overlay
724 	/* Then try to get a connected upper dir by index */
751 	/* Get a connected non-upper dir or disconnected non-dir */
838 	 * ovl_fh_to_dentry() returns connected dir overlay dentries and
848 	 * ovl_fh_to_dentry() returns connected dir overlay dentries, so we