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![Christian Brauner](/assets/img/avatar_default.png)
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b
("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
573 lines
13 KiB
C
573 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* 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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* Modified for NILFS by Amagai Yoshiji and Ryusuke Konishi.
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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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#include "export.h"
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#define NILFS_FID_SIZE_NON_CONNECTABLE \
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(offsetof(struct nilfs_fid, parent_gen) / 4)
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#define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4)
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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_new(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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unlock_new_inode(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, unsigned int flags)
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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 = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL;
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return d_splice_alias(inode, dentry);
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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 mnt_idmap *idmap, struct inode *dir,
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struct dentry *dentry, umode_t mode, bool excl)
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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 mnt_idmap *idmap, struct inode *dir,
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struct dentry *dentry, umode_t 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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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 mnt_idmap *idmap, struct inode *dir,
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struct dentry *dentry, 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 int 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 | 0777);
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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_nohighmem(inode);
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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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unlock_new_inode(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 = d_inode(old_dentry);
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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->i_ctime = current_time(inode);
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inode_inc_link_count(inode);
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ihold(inode);
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err = nilfs_add_link(dentry, inode);
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if (!err) {
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d_instantiate(dentry, inode);
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err = nilfs_transaction_commit(dir->i_sb);
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} else {
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inode_dec_link_count(inode);
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iput(inode);
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nilfs_transaction_abort(dir->i_sb);
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}
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return err;
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}
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static int nilfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
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struct dentry *dentry, umode_t 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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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_new(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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unlock_new_inode(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 = d_inode(dentry);
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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_warn(inode->i_sb,
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"deleting nonexistent file (ino=%lu), %d",
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inode->i_ino, inode->i_nlink);
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set_nlink(inode, 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(d_inode(dentry));
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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 = d_inode(dentry);
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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 mnt_idmap *idmap,
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struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry,
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unsigned int flags)
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{
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struct inode *old_inode = d_inode(old_dentry);
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struct inode *new_inode = d_inode(new_dentry);
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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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if (flags & ~RENAME_NOREPLACE)
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return -EINVAL;
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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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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(new_inode);
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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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err = nilfs_add_link(new_dentry, old_inode);
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if (err)
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goto out_dir;
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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(old_inode);
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nilfs_delete_entry(old_de, old_page);
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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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put_page(dir_page);
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}
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out_old:
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kunmap(old_page);
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put_page(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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/*
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* Export operations
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*/
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static 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 nilfs_root *root;
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ino = nilfs_inode_by_name(d_inode(child), &dotdot_name);
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if (!ino)
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return ERR_PTR(-ENOENT);
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root = NILFS_I(d_inode(child))->i_root;
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inode = nilfs_iget(child->d_sb, root, 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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static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
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u64 ino, u32 gen)
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{
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struct nilfs_root *root;
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struct inode *inode;
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if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
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return ERR_PTR(-ESTALE);
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root = nilfs_lookup_root(sb->s_fs_info, cno);
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if (!root)
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return ERR_PTR(-ESTALE);
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inode = nilfs_iget(sb, root, ino);
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nilfs_put_root(root);
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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if (gen && inode->i_generation != gen) {
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iput(inode);
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return ERR_PTR(-ESTALE);
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}
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return d_obtain_alias(inode);
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}
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static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
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int fh_len, int fh_type)
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{
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struct nilfs_fid *fid = (struct nilfs_fid *)fh;
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if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
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(fh_type != FILEID_NILFS_WITH_PARENT &&
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fh_type != FILEID_NILFS_WITHOUT_PARENT))
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return NULL;
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return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
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}
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static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
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int fh_len, int fh_type)
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{
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struct nilfs_fid *fid = (struct nilfs_fid *)fh;
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if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
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fh_type != FILEID_NILFS_WITH_PARENT)
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return NULL;
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return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
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}
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static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
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struct inode *parent)
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{
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struct nilfs_fid *fid = (struct nilfs_fid *)fh;
|
|
struct nilfs_root *root = NILFS_I(inode)->i_root;
|
|
int type;
|
|
|
|
if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
|
|
*lenp = NILFS_FID_SIZE_CONNECTABLE;
|
|
return FILEID_INVALID;
|
|
}
|
|
if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
|
|
*lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
|
|
return FILEID_INVALID;
|
|
}
|
|
|
|
fid->cno = root->cno;
|
|
fid->ino = inode->i_ino;
|
|
fid->gen = inode->i_generation;
|
|
|
|
if (parent) {
|
|
fid->parent_ino = parent->i_ino;
|
|
fid->parent_gen = parent->i_generation;
|
|
type = FILEID_NILFS_WITH_PARENT;
|
|
*lenp = NILFS_FID_SIZE_CONNECTABLE;
|
|
} else {
|
|
type = FILEID_NILFS_WITHOUT_PARENT;
|
|
*lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
|
|
}
|
|
|
|
return type;
|
|
}
|
|
|
|
const struct inode_operations nilfs_dir_inode_operations = {
|
|
.create = nilfs_create,
|
|
.lookup = nilfs_lookup,
|
|
.link = nilfs_link,
|
|
.unlink = nilfs_unlink,
|
|
.symlink = nilfs_symlink,
|
|
.mkdir = nilfs_mkdir,
|
|
.rmdir = nilfs_rmdir,
|
|
.mknod = nilfs_mknod,
|
|
.rename = nilfs_rename,
|
|
.setattr = nilfs_setattr,
|
|
.permission = nilfs_permission,
|
|
.fiemap = nilfs_fiemap,
|
|
.fileattr_get = nilfs_fileattr_get,
|
|
.fileattr_set = nilfs_fileattr_set,
|
|
};
|
|
|
|
const struct inode_operations nilfs_special_inode_operations = {
|
|
.setattr = nilfs_setattr,
|
|
.permission = nilfs_permission,
|
|
};
|
|
|
|
const struct inode_operations nilfs_symlink_inode_operations = {
|
|
.get_link = page_get_link,
|
|
.permission = nilfs_permission,
|
|
};
|
|
|
|
const struct export_operations nilfs_export_ops = {
|
|
.encode_fh = nilfs_encode_fh,
|
|
.fh_to_dentry = nilfs_fh_to_dentry,
|
|
.fh_to_parent = nilfs_fh_to_parent,
|
|
.get_parent = nilfs_get_parent,
|
|
};
|