Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936362AbWLDMjj (ORCPT ); Mon, 4 Dec 2006 07:39:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936367AbWLDMi7 (ORCPT ); Mon, 4 Dec 2006 07:38:59 -0500 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:17119 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S936362AbWLDMgJ (ORCPT ); Mon, 4 Dec 2006 07:36:09 -0500 From: "Josef 'Jeff' Sipek" To: linux-kernel@vger.kernel.org Cc: torvalds@osdl.org, akpm@osdl.org, hch@infradead.org, viro@ftp.linux.org.uk, linux-fsdevel@vger.kernel.org, mhalcrow@us.ibm.com, Josef "Jeff" Sipek Subject: [PATCH 28/35] Unionfs: Miscellaneous helper functions Date: Mon, 4 Dec 2006 07:31:01 -0500 Message-Id: <11652354723615-git-send-email-jsipek@cs.sunysb.edu> X-Mailer: git-send-email 1.4.3.3 In-Reply-To: <1165235468365-git-send-email-jsipek@cs.sunysb.edu> References: <1165235468365-git-send-email-jsipek@cs.sunysb.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5704 Lines: 195 From: Josef "Jeff" Sipek This patch contains miscellaneous helper functions used thoughout Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- fs/unionfs/subr.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 170 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/subr.c b/fs/unionfs/subr.c new file mode 100644 index 0000000..f002f19 --- /dev/null +++ b/fs/unionfs/subr.c @@ -0,0 +1,170 @@ +/* + * 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" + +/* Pass an unionfs dentry and an index. It will try to create a whiteout + * for the filename in dentry, and will try in branch 'index'. On error, + * it will proceed to a branch to the left. + */ +int create_whiteout(struct dentry *dentry, int start) +{ + int bstart, bend, bindex; + struct dentry *hidden_dir_dentry; + struct dentry *hidden_dentry; + struct dentry *hidden_wh_dentry; + char *name = NULL; + int err = -EINVAL; + + verify_locked(dentry); + + bstart = dbstart(dentry); + bend = dbend(dentry); + + /* create dentry's whiteout equivalent */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (IS_ERR(name)) { + err = PTR_ERR(name); + goto out; + } + + for (bindex = start; bindex >= 0; bindex--) { + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); + + if (!hidden_dentry) { + /* if hidden dentry is not present, create the entire + * hidden dentry directory structure and go ahead. + * Since we want to just create whiteout, we only want + * the parent dentry, and hence get rid of this dentry. + */ + hidden_dentry = create_parents(dentry->d_inode, + dentry, bindex); + if (!hidden_dentry || IS_ERR(hidden_dentry)) { + printk(KERN_DEBUG "create_parents failed for " + "bindex = %d\n", bindex); + continue; + } + } + + hidden_wh_dentry = lookup_one_len(name, hidden_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(hidden_wh_dentry)) + continue; + + /* The whiteout already exists. This used to be impossible, but + * now is possible because of opaqueness. */ + if (hidden_wh_dentry->d_inode) { + dput(hidden_wh_dentry); + err = 0; + goto out; + } + + hidden_dir_dentry = lock_parent(hidden_wh_dentry); + if (!(err = is_robranch_super(dentry->d_sb, bindex))) { + err = vfs_create(hidden_dir_dentry->d_inode, + hidden_wh_dentry, + ~current->fs->umask & S_IRWXUGO, NULL); + + } + unlock_dir(hidden_dir_dentry); + dput(hidden_wh_dentry); + + if (!err || !IS_COPYUP_ERR(err)) + break; + } + + /* set dbopaque so that lookup will not proceed after this branch */ + if (!err) + set_dbopaque(dentry, bindex); + +out: + kfree(name); + return err; +} + +/* This is a helper function for rename, which ends up with hosed over dentries + * when it needs to revert. */ +int unionfs_refresh_hidden_dentry(struct dentry *dentry, int bindex) +{ + struct dentry *hidden_dentry; + struct dentry *hidden_parent; + int err = 0; + + verify_locked(dentry); + + lock_dentry(dentry->d_parent); + hidden_parent = unionfs_lower_dentry_idx(dentry->d_parent, bindex); + unlock_dentry(dentry->d_parent); + + BUG_ON(!S_ISDIR(hidden_parent->d_inode->i_mode)); + + hidden_dentry = lookup_one_len(dentry->d_name.name, hidden_parent, + dentry->d_name.len); + if (IS_ERR(hidden_dentry)) { + err = PTR_ERR(hidden_dentry); + goto out; + } + + dput(unionfs_lower_dentry_idx(dentry, bindex)); + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, NULL); + + if (!hidden_dentry->d_inode) { + dput(hidden_dentry); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + } else { + unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + igrab(hidden_dentry->d_inode)); + } + +out: + return err; +} + +int make_dir_opaque(struct dentry *dentry, int bindex) +{ + int err = 0; + struct dentry *hidden_dentry, *diropq; + struct inode *hidden_dir; + + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); + hidden_dir = hidden_dentry->d_inode; + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode) || + !S_ISDIR(hidden_dir->i_mode)); + + mutex_lock(&hidden_dir->i_mutex); + diropq = lookup_one_len(UNIONFS_DIR_OPAQUE, hidden_dentry, + sizeof(UNIONFS_DIR_OPAQUE) - 1); + if (IS_ERR(diropq)) { + err = PTR_ERR(diropq); + goto out; + } + + if (!diropq->d_inode) + err = vfs_create(hidden_dir, diropq, S_IRUGO, NULL); + if (!err) + set_dbopaque(dentry, bindex); + + dput(diropq); + +out: + mutex_unlock(&hidden_dir->i_mutex); + return err; +} + -- 1.4.3.3 - 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/