495 lines
11 KiB
C
495 lines
11 KiB
C
/*
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* namei.c - NILFS pathname lookup operations.
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*
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>,
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* Ryusuke Konishi <ryusuke@osrg.net>
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*/
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/*
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* linux/fs/ext2/namei.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/namei.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Big-endian to little-endian byte-swapping/bitmaps by
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* David S. Miller (davem@caip.rutgers.edu), 1995
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*/
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#include <linux/pagemap.h>
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#include "nilfs.h"
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static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
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{
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int err = nilfs_add_link(dentry, inode);
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if (!err) {
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d_instantiate(dentry, inode);
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return 0;
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}
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inode_dec_link_count(inode);
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iput(inode);
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return err;
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}
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/*
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* Methods themselves.
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*/
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static struct dentry *
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nilfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *inode;
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ino_t ino;
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if (dentry->d_name.len > NILFS_NAME_LEN)
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return ERR_PTR(-ENAMETOOLONG);
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ino = nilfs_inode_by_name(dir, &dentry->d_name);
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inode = NULL;
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if (ino) {
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inode = nilfs_iget(dir->i_sb, ino);
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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}
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return d_splice_alias(inode, dentry);
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}
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struct dentry *nilfs_get_parent(struct dentry *child)
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{
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unsigned long ino;
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struct inode *inode;
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struct qstr dotdot = {.name = "..", .len = 2};
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ino = nilfs_inode_by_name(child->d_inode, &dotdot);
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if (!ino)
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return ERR_PTR(-ENOENT);
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inode = nilfs_iget(child->d_inode->i_sb, ino);
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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return d_obtain_alias(inode);
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}
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/*
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* By the time this is called, we already have created
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* the directory cache entry for the new file, but it
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* is so far negative - it has no inode.
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*
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* If the create succeeds, we fill in the inode information
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* with d_instantiate().
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*/
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static int nilfs_create(struct inode *dir, struct dentry *dentry, int mode,
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struct nameidata *nd)
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{
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struct inode *inode;
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struct nilfs_transaction_info ti;
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int err;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
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if (err)
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return err;
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inode = nilfs_new_inode(dir, mode);
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err = PTR_ERR(inode);
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if (!IS_ERR(inode)) {
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inode->i_op = &nilfs_file_inode_operations;
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inode->i_fop = &nilfs_file_operations;
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inode->i_mapping->a_ops = &nilfs_aops;
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nilfs_mark_inode_dirty(inode);
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err = nilfs_add_nondir(dentry, inode);
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}
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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}
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static int
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nilfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
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{
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struct inode *inode;
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struct nilfs_transaction_info ti;
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int err;
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if (!new_valid_dev(rdev))
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return -EINVAL;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
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if (err)
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return err;
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inode = nilfs_new_inode(dir, mode);
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err = PTR_ERR(inode);
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if (!IS_ERR(inode)) {
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init_special_inode(inode, inode->i_mode, rdev);
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nilfs_mark_inode_dirty(inode);
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err = nilfs_add_nondir(dentry, inode);
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}
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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}
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static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
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const char *symname)
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{
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struct nilfs_transaction_info ti;
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struct super_block *sb = dir->i_sb;
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unsigned l = strlen(symname)+1;
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struct inode *inode;
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int err;
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if (l > sb->s_blocksize)
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return -ENAMETOOLONG;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
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if (err)
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return err;
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inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO);
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err = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out;
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/* slow symlink */
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inode->i_op = &nilfs_symlink_inode_operations;
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inode->i_mapping->a_ops = &nilfs_aops;
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err = page_symlink(inode, symname, l);
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if (err)
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goto out_fail;
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/* mark_inode_dirty(inode); */
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/* page_symlink() do this */
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err = nilfs_add_nondir(dentry, inode);
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out:
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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out_fail:
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drop_nlink(inode);
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nilfs_mark_inode_dirty(inode);
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iput(inode);
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goto out;
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}
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static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
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struct dentry *dentry)
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{
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struct inode *inode = old_dentry->d_inode;
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struct nilfs_transaction_info ti;
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int err;
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if (inode->i_nlink >= NILFS_LINK_MAX)
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return -EMLINK;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
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if (err)
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return err;
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inode->i_ctime = CURRENT_TIME;
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inode_inc_link_count(inode);
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atomic_inc(&inode->i_count);
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err = nilfs_add_nondir(dentry, inode);
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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}
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static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
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{
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struct inode *inode;
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struct nilfs_transaction_info ti;
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int err;
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if (dir->i_nlink >= NILFS_LINK_MAX)
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return -EMLINK;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
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if (err)
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return err;
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inc_nlink(dir);
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inode = nilfs_new_inode(dir, S_IFDIR | mode);
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err = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out_dir;
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inode->i_op = &nilfs_dir_inode_operations;
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inode->i_fop = &nilfs_dir_operations;
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inode->i_mapping->a_ops = &nilfs_aops;
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inc_nlink(inode);
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err = nilfs_make_empty(inode, dir);
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if (err)
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goto out_fail;
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err = nilfs_add_link(dentry, inode);
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if (err)
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goto out_fail;
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nilfs_mark_inode_dirty(inode);
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d_instantiate(dentry, inode);
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out:
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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out_fail:
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drop_nlink(inode);
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drop_nlink(inode);
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nilfs_mark_inode_dirty(inode);
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iput(inode);
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out_dir:
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drop_nlink(dir);
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nilfs_mark_inode_dirty(dir);
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goto out;
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}
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static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct inode *inode;
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struct nilfs_dir_entry *de;
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struct page *page;
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int err;
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err = -ENOENT;
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de = nilfs_find_entry(dir, &dentry->d_name, &page);
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if (!de)
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goto out;
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inode = dentry->d_inode;
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err = -EIO;
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if (le64_to_cpu(de->inode) != inode->i_ino)
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goto out;
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if (!inode->i_nlink) {
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nilfs_warning(inode->i_sb, __func__,
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"deleting nonexistent file (%lu), %d\n",
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inode->i_ino, inode->i_nlink);
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inode->i_nlink = 1;
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}
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err = nilfs_delete_entry(de, page);
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if (err)
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goto out;
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inode->i_ctime = dir->i_ctime;
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drop_nlink(inode);
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err = 0;
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out:
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return err;
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}
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static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct nilfs_transaction_info ti;
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int err;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
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if (err)
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return err;
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err = nilfs_do_unlink(dir, dentry);
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if (!err) {
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nilfs_mark_inode_dirty(dir);
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nilfs_mark_inode_dirty(dentry->d_inode);
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err = nilfs_transaction_commit(dir->i_sb);
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} else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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}
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static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
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{
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struct inode *inode = dentry->d_inode;
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struct nilfs_transaction_info ti;
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int err;
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err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
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if (err)
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return err;
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err = -ENOTEMPTY;
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if (nilfs_empty_dir(inode)) {
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err = nilfs_do_unlink(dir, dentry);
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if (!err) {
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inode->i_size = 0;
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drop_nlink(inode);
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nilfs_mark_inode_dirty(inode);
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drop_nlink(dir);
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nilfs_mark_inode_dirty(dir);
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}
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}
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if (!err)
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err = nilfs_transaction_commit(dir->i_sb);
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else
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nilfs_transaction_abort(dir->i_sb);
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return err;
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}
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static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry)
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{
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struct inode *old_inode = old_dentry->d_inode;
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struct inode *new_inode = new_dentry->d_inode;
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struct page *dir_page = NULL;
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struct nilfs_dir_entry *dir_de = NULL;
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struct page *old_page;
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struct nilfs_dir_entry *old_de;
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struct nilfs_transaction_info ti;
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int err;
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err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
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if (unlikely(err))
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return err;
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err = -ENOENT;
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old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page);
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if (!old_de)
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goto out;
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if (S_ISDIR(old_inode->i_mode)) {
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err = -EIO;
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dir_de = nilfs_dotdot(old_inode, &dir_page);
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if (!dir_de)
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goto out_old;
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}
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if (new_inode) {
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struct page *new_page;
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struct nilfs_dir_entry *new_de;
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err = -ENOTEMPTY;
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if (dir_de && !nilfs_empty_dir(new_inode))
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goto out_dir;
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err = -ENOENT;
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new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page);
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if (!new_de)
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goto out_dir;
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inc_nlink(old_inode);
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nilfs_set_link(new_dir, new_de, new_page, old_inode);
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nilfs_mark_inode_dirty(new_dir);
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new_inode->i_ctime = CURRENT_TIME;
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if (dir_de)
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drop_nlink(new_inode);
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drop_nlink(new_inode);
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nilfs_mark_inode_dirty(new_inode);
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} else {
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if (dir_de) {
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err = -EMLINK;
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if (new_dir->i_nlink >= NILFS_LINK_MAX)
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goto out_dir;
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}
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inc_nlink(old_inode);
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err = nilfs_add_link(new_dentry, old_inode);
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if (err) {
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drop_nlink(old_inode);
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nilfs_mark_inode_dirty(old_inode);
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goto out_dir;
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}
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if (dir_de) {
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inc_nlink(new_dir);
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nilfs_mark_inode_dirty(new_dir);
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}
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}
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/*
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* Like most other Unix systems, set the ctime for inodes on a
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* rename.
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*/
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old_inode->i_ctime = CURRENT_TIME;
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nilfs_delete_entry(old_de, old_page);
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drop_nlink(old_inode);
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if (dir_de) {
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nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
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drop_nlink(old_dir);
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}
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nilfs_mark_inode_dirty(old_dir);
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nilfs_mark_inode_dirty(old_inode);
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err = nilfs_transaction_commit(old_dir->i_sb);
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return err;
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out_dir:
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if (dir_de) {
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kunmap(dir_page);
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page_cache_release(dir_page);
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}
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out_old:
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kunmap(old_page);
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page_cache_release(old_page);
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out:
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nilfs_transaction_abort(old_dir->i_sb);
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return err;
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}
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const struct inode_operations nilfs_dir_inode_operations = {
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.create = nilfs_create,
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.lookup = nilfs_lookup,
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.link = nilfs_link,
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.unlink = nilfs_unlink,
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.symlink = nilfs_symlink,
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.mkdir = nilfs_mkdir,
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.rmdir = nilfs_rmdir,
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.mknod = nilfs_mknod,
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.rename = nilfs_rename,
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.setattr = nilfs_setattr,
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.permission = nilfs_permission,
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};
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const struct inode_operations nilfs_special_inode_operations = {
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.setattr = nilfs_setattr,
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.permission = nilfs_permission,
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};
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const struct inode_operations nilfs_symlink_inode_operations = {
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.readlink = generic_readlink,
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.follow_link = page_follow_link_light,
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.put_link = page_put_link,
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};
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