Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936427AbWLDMmY (ORCPT ); Mon, 4 Dec 2006 07:42:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936350AbWLDMlu (ORCPT ); Mon, 4 Dec 2006 07:41:50 -0500 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:735 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S936331AbWLDMfR (ORCPT ); Mon, 4 Dec 2006 07:35:17 -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 20/35] Unionfs: Directory manipulation helper functions Date: Mon, 4 Dec 2006 07:30:53 -0500 Message-Id: <11652354711791-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: 7871 Lines: 295 From: Josef "Jeff" Sipek This patch contains directory manipulation helper functions. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- fs/unionfs/dirhelper.c | 270 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 270 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/dirhelper.c b/fs/unionfs/dirhelper.c new file mode 100644 index 0000000..714af2d --- /dev/null +++ b/fs/unionfs/dirhelper.c @@ -0,0 +1,270 @@ +/* + * 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" + +/* Delete all of the whiteouts in a given directory for rmdir. + * + * hidden directory inode should be locked + */ +int do_delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist) +{ + int err = 0; + struct dentry *hidden_dir_dentry = NULL; + struct dentry *hidden_dentry; + char *name = NULL, *p; + struct inode *hidden_dir; + + int i; + struct list_head *pos; + struct filldir_node *cursor; + + /* Find out hidden parent dentry */ + hidden_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); + BUG_ON(!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)); + hidden_dir = hidden_dir_dentry->d_inode; + BUG_ON(!S_ISDIR(hidden_dir->i_mode)); + + err = -ENOMEM; + name = __getname(); + if (!name) + goto out; + strcpy(name, UNIONFS_WHPFX); + p = name + UNIONFS_WHLEN; + + err = 0; + for (i = 0; !err && i < namelist->size; i++) { + list_for_each(pos, &namelist->list[i]) { + cursor = + list_entry(pos, struct filldir_node, file_list); + /* Only operate on whiteouts in this branch. */ + if (cursor->bindex != bindex) + continue; + if (!cursor->whiteout) + continue; + + strcpy(p, cursor->name); + hidden_dentry = + lookup_one_len(name, hidden_dir_dentry, + cursor->namelen + UNIONFS_WHLEN); + if (IS_ERR(hidden_dentry)) { + err = PTR_ERR(hidden_dentry); + break; + } + if (hidden_dentry->d_inode) + err = vfs_unlink(hidden_dir, hidden_dentry); + dput(hidden_dentry); + if (err) + break; + } + } + + __putname(name); + + /* After all of the removals, we should copy the attributes once. */ + fsstack_copy_attr_times(dentry->d_inode, hidden_dir_dentry->d_inode); + +out: + return err; +} + +/* delete whiteouts in a dir (for rmdir operation) using sioq if necessary */ +int delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist) +{ + int err; + struct super_block *sb; + struct dentry *hidden_dir_dentry; + struct inode *hidden_dir; + + struct sioq_args args; + + sb = dentry->d_sb; + unionfs_read_lock(sb); + + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); + BUG_ON(bindex < dbstart(dentry)); + BUG_ON(bindex > dbend(dentry)); + err = is_robranch_super(sb, bindex); + if (err) + goto out; + + hidden_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); + BUG_ON(!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)); + hidden_dir = hidden_dir_dentry->d_inode; + BUG_ON(!S_ISDIR(hidden_dir->i_mode)); + + mutex_lock(&hidden_dir->i_mutex); + if (!permission(hidden_dir, MAY_WRITE | MAY_EXEC, NULL)) + err = do_delete_whiteouts(dentry, bindex, namelist); + else { + args.deletewh.namelist = namelist; + args.deletewh.dentry = dentry; + args.deletewh.bindex = bindex; + run_sioq(__delete_whiteouts, &args); + err = args.err; + } + mutex_unlock(&hidden_dir->i_mutex); + +out: + unionfs_read_unlock(sb); + return err; +} + +#define RD_NONE 0 +#define RD_CHECK_EMPTY 1 +/* The callback structure for check_empty. */ +struct unionfs_rdutil_callback { + int err; + int filldir_called; + struct unionfs_dir_state *rdstate; + int mode; +}; + +/* This filldir function makes sure only whiteouts exist within a directory. */ +static int readdir_util_callback(void *dirent, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + int err = 0; + struct unionfs_rdutil_callback *buf = dirent; + int whiteout = 0; + struct filldir_node *found; + + buf->filldir_called = 1; + + if (name[0] == '.' + && (namelen == 1 || (name[1] == '.' && namelen == 2))) + goto out; + + if (namelen > UNIONFS_WHLEN && !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { + namelen -= UNIONFS_WHLEN; + name += UNIONFS_WHLEN; + whiteout = 1; + } + + found = find_filldir_node(buf->rdstate, name, namelen); + /* If it was found in the table there was a previous whiteout. */ + if (found) + goto out; + + /* If it wasn't found and isn't a whiteout, the directory isn't empty. */ + err = -ENOTEMPTY; + if ((buf->mode == RD_CHECK_EMPTY) && !whiteout) + goto out; + + err = add_filldir_node(buf->rdstate, name, namelen, + buf->rdstate->bindex, whiteout); + +out: + buf->err = err; + return err; +} + +/* Is a directory logically empty? */ +int check_empty(struct dentry *dentry, struct unionfs_dir_state **namelist) +{ + int err = 0; + struct dentry *hidden_dentry = NULL; + struct super_block *sb; + struct file *hidden_file; + struct unionfs_rdutil_callback *buf = NULL; + int bindex, bstart, bend, bopaque; + + sb = dentry->d_sb; + + unionfs_read_lock(sb); + + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); + + if ((err = unionfs_partial_lookup(dentry))) + goto out; + + bstart = dbstart(dentry); + bend = dbend(dentry); + bopaque = dbopaque(dentry); + if (0 <= bopaque && bopaque < bend) + bend = bopaque; + + buf = kmalloc(sizeof(struct unionfs_rdutil_callback), GFP_KERNEL); + if (!buf) { + err = -ENOMEM; + goto out; + } + buf->err = 0; + buf->mode = RD_CHECK_EMPTY; + buf->rdstate = alloc_rdstate(dentry->d_inode, bstart); + if (!buf->rdstate) { + err = -ENOMEM; + goto out; + } + + /* Process the hidden directories with rdutil_callback as a filldir. */ + for (bindex = bstart; bindex <= bend; bindex++) { + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!hidden_dentry) + continue; + if (!hidden_dentry->d_inode) + continue; + if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) + continue; + + dget(hidden_dentry); + mntget(unionfs_lower_mnt_idx(dentry, bindex)); + branchget(sb, bindex); + hidden_file = + dentry_open(hidden_dentry, unionfs_lower_mnt_idx(dentry, bindex), + O_RDONLY); + if (IS_ERR(hidden_file)) { + err = PTR_ERR(hidden_file); + dput(hidden_dentry); + branchput(sb, bindex); + goto out; + } + + do { + buf->filldir_called = 0; + buf->rdstate->bindex = bindex; + err = vfs_readdir(hidden_file, + readdir_util_callback, buf); + if (buf->err) + err = buf->err; + } while ((err >= 0) && buf->filldir_called); + + /* fput calls dput for hidden_dentry */ + fput(hidden_file); + branchput(sb, bindex); + + if (err < 0) + goto out; + } + +out: + if (buf) { + if (namelist && !err) + *namelist = buf->rdstate; + else if (buf->rdstate) + free_rdstate(buf->rdstate); + kfree(buf); + } + + unionfs_read_unlock(sb); + + 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/