Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932581AbWJGFyz (ORCPT ); Sat, 7 Oct 2006 01:54:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932583AbWJGFyw (ORCPT ); Sat, 7 Oct 2006 01:54:52 -0400 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:51632 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S932422AbWJGFyu (ORCPT ); Sat, 7 Oct 2006 01:54:50 -0400 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 22 of 23] Unionfs: Unlink Message-Id: In-Reply-To: Date: Sat, 07 Oct 2006 01:07:41 -0400 From: Josef "Jeff" Sipek To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, torvalds@osdl.org, akpm@osdl.org, hch@infradead.org, viro@ftp.linux.org.uk Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5471 Lines: 202 From: Josef "Jeff" Sipek This patch provides unlink functionality for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- 1 file changed, 178 insertions(+) fs/unionfs/unlink.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++++ diff -r 606b1edca92c -r a20795e821a8 fs/unionfs/unlink.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/fs/unionfs/unlink.c Sat Oct 07 00:46:20 2006 -0400 @@ -0,0 +1,178 @@ +/* + * Copyright (c) 2003-2006 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2006 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2006 Stony Brook University + * Copyright (c) 2003-2006 The Research Foundation of State University of New York + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry) +{ + struct dentry *hidden_dentry; + struct dentry *hidden_dir_dentry; + int bindex; + int err = 0; + + if ((err = unionfs_partial_lookup(dentry))) + goto out; + + bindex = dbstart(dentry); + + hidden_dentry = dtohd_index(dentry, bindex); + if (!hidden_dentry) + goto out; + + hidden_dir_dentry = lock_parent(hidden_dentry); + + /* avoid destroying the hidden inode if the file is in use */ + dget(hidden_dentry); + if (!(err = is_robranch_super(dentry->d_sb, bindex))) + err = vfs_unlink(hidden_dir_dentry->d_inode, hidden_dentry); + dput(hidden_dentry); + fist_copy_attr_times(dir, hidden_dir_dentry->d_inode); + unlock_dir(hidden_dir_dentry); + + if (err && !IS_COPYUP_ERR(err)) + goto out; + + if (err) { + if (dbstart(dentry) == 0) + goto out; + + err = create_whiteout(dentry, dbstart(dentry) - 1); + } else if (dbopaque(dentry) != -1) { + /* There is a hidden lower-priority file with the same name. */ + err = create_whiteout(dentry, dbopaque(dentry)); + } else { + err = create_whiteout(dentry, dbstart(dentry)); + } + +out: + if (!err) + dentry->d_inode->i_nlink--; + + /* We don't want to leave negative leftover dentries for revalidate. */ + if (!err && (dbopaque(dentry) != -1)) + update_bstart(dentry); + + return err; +} + +int unionfs_unlink(struct inode *dir, struct dentry *dentry) +{ + int err = 0; + + lock_dentry(dentry); + + err = unionfs_unlink_whiteout(dir, dentry); + /* call d_drop so the system "forgets" about us */ + if (!err) + d_drop(dentry); + + unlock_dentry(dentry); + return err; +} + +static int unionfs_rmdir_first(struct inode *dir, struct dentry *dentry, + struct unionfs_dir_state *namelist) +{ + int err; + struct dentry *hidden_dentry; + struct dentry *hidden_dir_dentry = NULL; + + /* Here we need to remove whiteout entries. */ + err = delete_whiteouts(dentry, dbstart(dentry), namelist); + if (err) { + goto out; + } + + hidden_dentry = dtohd(dentry); + + hidden_dir_dentry = lock_parent(hidden_dentry); + + /* avoid destroying the hidden inode if the file is in use */ + dget(hidden_dentry); + if (!(err = is_robranch(dentry))) { + err = vfs_rmdir(hidden_dir_dentry->d_inode, hidden_dentry); + } + dput(hidden_dentry); + + fist_copy_attr_times(dir, hidden_dir_dentry->d_inode); + /* propagate number of hard-links */ + dentry->d_inode->i_nlink = get_nlinks(dentry->d_inode); + +out: + if (hidden_dir_dentry) { + unlock_dir(hidden_dir_dentry); + } + return err; +} + +int unionfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + int err = 0; + struct unionfs_dir_state *namelist = NULL; + + lock_dentry(dentry); + + /* check if this unionfs directory is empty or not */ + err = check_empty(dentry, &namelist); + if (err) { +#if 0 + /* vfs_rmdir(our caller) unhashed the dentry. This will recover + * the Unionfs inode number for the directory itself, but the + * children are already lost. It seems that tmpfs manages its + * way around this by upping the refcount on everything. + * + * Even if we do this, we still lose the inode numbers of the + * children. The best way to fix this is to fix the VFS (or + * use persistent inode maps). */ + if (d_unhashed(dentry)) + d_rehash(dentry); +#endif + goto out; + } + + err = unionfs_rmdir_first(dir, dentry, namelist); + /* create whiteout */ + if (!err) { + err = create_whiteout(dentry, dbstart(dentry)); + } else { + int new_err; + + if (dbstart(dentry) == 0) + goto out; + + /* exit if the error returned was NOT -EROFS */ + if (!IS_COPYUP_ERR(err)) + goto out; + + new_err = create_whiteout(dentry, dbstart(dentry) - 1); + if (new_err != -EEXIST) + err = new_err; + } + +out: + /* call d_drop so the system "forgets" about us */ + if (!err) + d_drop(dentry); + + if (namelist) + free_rdstate(namelist); + + unlock_dentry(dentry); + return err; +} + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/