1 // SPDX-License-Identifier: GPL-2.0-only
7  * Copyright (C) 2017-2018 CTERA Networks. All Rights Reserved.
33 		pr_warn_ratelimited("failed to copy up on encode (%pd2, err=%i)\n",  in ovl_encode_maybe_copy_up()
41  * Before encoding a non-upper directory file handle from real layer N, we need
59  * /a/b/c, which is "layer 2 connectable", on encode time. That ancestor is
82 	if (dentry == dentry->d_sb->s_root)  in ovl_connectable_layer()
83 		return oe->numlower;  in ovl_connectable_layer()
94 	return oe->lowerstack[0].layer->idx;  in ovl_connectable_layer()
111 	if (WARN_ON(dentry == dentry->d_sb->s_root) ||  in ovl_connect_layer()
113 		return -EIO;  in ovl_connect_layer()
115 	origin_layer = OVL_E(dentry)->lowerstack[0].layer->idx;  in ovl_connect_layer()
124 			err = -EIO;  in ovl_connect_layer()
156  * We only need to encode origin if there is a chance that the same object was
158  * encoding also after copy up. If non-pure upper is not indexed, then it was
160  * about staying consistent with pre copy up encoding and we encode an upper
161  * file handle. Overlay root dentry is a private case of non-indexed upper.
167  * --------------------------------
169  *  Non-indexed upper	| U
171  *  Non-upper		| L (*)
177  * possible when there are redirects in lower layers and non-indexed merge dirs.
178  * To mitigate those case, we may copy up the lower dir ancestor before encode
185 	struct ovl_fs *ofs = dentry->d_sb->s_fs_info;  in ovl_check_encode_origin()
192 	 * Upper file handle for non-indexed upper.  in ovl_check_encode_origin()
194 	 * Root is never indexed, so if there's an upper layer, encode upper for  in ovl_check_encode_origin()
203 	 * lower dir or under a non-indexed upper is not always possible.  in ovl_check_encode_origin()
210 	/* Lower file handle for indexed and non-upper dir/non-dir */  in ovl_check_encode_origin()
222 	 * Check if we should encode a lower or upper file handle and maybe  in ovl_dentry_to_fid()
229 	/* Encode an upper or lower file handle */  in ovl_dentry_to_fid()
245 	pr_warn_ratelimited("failed to encode file handle (%pd2, err=%i)\n",  in ovl_dentry_to_fid()
253 	struct ovl_fs *ofs = OVL_FS(inode->i_sb);  in ovl_encode_fh()
257 	/* TODO: encode connectable file handles */  in ovl_encode_fh()
285 	struct dentry *lower = lowerpath ? lowerpath->dentry : NULL;  in ovl_obtain_alias()
298 		return ERR_PTR(-EIO);  in ovl_obtain_alias()
314 	dentry = d_alloc_anon(inode->i_sb);  in ovl_obtain_alias()
322 		oe->lowerstack->dentry = dget(lower);  in ovl_obtain_alias()
323 		oe->lowerstack->layer = lowerpath->layer;  in ovl_obtain_alias()
325 	dentry->d_fsdata = oe;  in ovl_obtain_alias()
336 	dentry = ERR_PTR(-ENOMEM);  in ovl_obtain_alias()
345 	struct ovl_entry *oe = dentry->d_fsdata;  in ovl_dentry_real_at()
351 	for (i = 0; i < oe->numlower; i++) {  in ovl_dentry_real_at()
352 		if (oe->lowerstack[i].layer->idx == idx)  in ovl_dentry_real_at()
353 			return oe->lowerstack[i].dentry;  in ovl_dentry_real_at()
378 	 * connected overlay dir, we return -ECHILD and restart the lookup of  in ovl_lookup_real_one()
382 	err = -ECHILD;  in ovl_lookup_real_one()
384 	if (ovl_dentry_real_at(connected, layer->idx) != parent)  in ovl_lookup_real_one()
390 	 * care about returning ESTALE, only from dereferencing a free name  in ovl_lookup_real_one()
396 	 * permission checking altogether, but for now just use non-mnt_userns  in ovl_lookup_real_one()
404 	} else if (!this || !this->d_inode) {  in ovl_lookup_real_one()
406 		err = -ENOENT;  in ovl_lookup_real_one()
408 	} else if (ovl_dentry_real_at(this, layer->idx) != real) {  in ovl_lookup_real_one()
410 		err = -ESTALE;  in ovl_lookup_real_one()
421 			    real, layer->idx, connected, err);  in ovl_lookup_real_one()
437 	struct ovl_fs *ofs = sb->s_fs_info;  in ovl_lookup_real_inode()
446 	inode = ovl_lookup_inode(sb, real, !layer->idx);  in ovl_lookup_real_inode()
458 	if (!this && layer->idx && ofs->indexdir && !WARN_ON(!d_is_dir(real))) {  in ovl_lookup_real_inode()
479 		this = ovl_lookup_real(sb, upper, &ofs->layers[0]);  in ovl_lookup_real_inode()
486 	if (ovl_dentry_real_at(this, layer->idx) != real) {  in ovl_lookup_real_inode()
488 		this = ERR_PTR(-EIO);  in ovl_lookup_real_inode()
503 	struct dentry *ancestor = ERR_PTR(-EIO);  in ovl_lookup_real_ancestor()
505 	if (real == layer->mnt->mnt_root)  in ovl_lookup_real_ancestor()
506 		return dget(sb->s_root);  in ovl_lookup_real_ancestor()
521 		if (parent == layer->mnt->mnt_root) {  in ovl_lookup_real_ancestor()
522 			ancestor = dget(sb->s_root);  in ovl_lookup_real_ancestor()
532 			ancestor = ERR_PTR(-EXDEV);  in ovl_lookup_real_ancestor()
566 								   layer->idx);  in ovl_lookup_real()
587 			if (parent == layer->mnt->mnt_root) {  in ovl_lookup_real()
589 				connected = dget(sb->s_root);  in ovl_lookup_real()
600 				err = -EXDEV;  in ovl_lookup_real()
623 			if (err == -ECHILD) {  in ovl_lookup_real()
645 			    real, layer->idx, connected, err);  in ovl_lookup_real()
658 	struct ovl_fs *ofs = sb->s_fs_info;  in ovl_get_dentry()
659 	const struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer;  in ovl_get_dentry()
660 	struct dentry *real = upper ?: (index ?: lowerpath->dentry);  in ovl_get_dentry()
663 	 * Obtain a disconnected overlay dentry from a non-dir real dentry  in ovl_get_dentry()
670 	if ((real->d_flags & DCACHE_DISCONNECTED) || d_unhashed(real))  in ovl_get_dentry()
671 		return ERR_PTR(-ENOENT);  in ovl_get_dentry()
683 	struct ovl_fs *ofs = sb->s_fs_info;  in ovl_upper_fh_to_d()
688 		return ERR_PTR(-EACCES);  in ovl_upper_fh_to_d()
703 	struct ovl_fs *ofs = sb->s_fs_info;  in ovl_lower_fh_to_d()
717 	    !(origin.dentry->d_flags & DCACHE_DISCONNECTED)) {  in ovl_lower_fh_to_d()
731 	if (ofs->indexdir) {  in ovl_lower_fh_to_d()
767 	/* Get a connected non-upper dir or disconnected non-dir */  in ovl_lower_fh_to_d()
784 	/* If on-wire inner fid is aligned - nothing to do */  in ovl_fid_to_fh()
789 		return ERR_PTR(-EINVAL);  in ovl_fid_to_fh()
792 		return ERR_PTR(-EINVAL);  in ovl_fid_to_fh()
796 		return ERR_PTR(-ENOMEM);  in ovl_fid_to_fh()
799 	memcpy(&fh->fb, fid, buflen - OVL_FH_WIRE_OFFSET);  in ovl_fid_to_fh()
821 	flags = fh->fb.flags;  in ovl_fh_to_dentry()
826 	if (IS_ERR(dentry) && err != -ESTALE)  in ovl_fh_to_dentry()
830 	/* We may have needed to re-align OVL_FILEID_V0 */  in ovl_fh_to_dentry()
847 	return ERR_PTR(-EACCES);  in ovl_fh_to_parent()
858 	return -EIO;  in ovl_get_name()
868 	return ERR_PTR(-EIO);  in ovl_get_parent()