// SPDX-License-Identifier: GPL-2.0+
/*
* NILFS pathname lookup operations.
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* Modified for NILFS by Amagai Yoshiji and Ryusuke Konishi.
*/
/*
* linux/fs/ext2/namei.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card ([email protected])
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller ([email protected]), 1995
*/
#include <linux/pagemap.h>
#include "nilfs.h"
#include "export.h"
#define NILFS_FID_SIZE_NON_CONNECTABLE \
(offsetof(struct nilfs_fid, parent_gen) / 4)
#define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4)
static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = nilfs_add_link(dentry, inode);
if (!err) {
d_instantiate_new(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
unlock_new_inode(inode);
iput(inode);
return err;
}
/*
* Methods themselves.
*/
static struct dentry *
nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
ino_t ino;
if (dentry->d_name.len > NILFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ino = nilfs_inode_by_name(dir, &dentry->d_name);
inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL;
return d_splice_alias(inode, dentry);
}
/*
* By the time this is called, we already have created
* the directory cache entry for the new file, but it
* is so far negative - it has no inode.
*
* If the create succeeds, we fill in the inode information
* with d_instantiate().
*/
static int nilfs_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inode = nilfs_new_inode(dir, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &nilfs_file_inode_operations;
inode->i_fop = &nilfs_file_operations;
inode->i_mapping->a_ops = &nilfs_aops;
nilfs_mark_inode_dirty(inode);
err = nilfs_add_nondir(dentry, inode);
}
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int
nilfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inode = nilfs_new_inode(dir, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
nilfs_mark_inode_dirty(inode);
err = nilfs_add_nondir(dentry, inode);
}
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *symname)
{
struct nilfs_transaction_info ti;
struct super_block *sb = dir->i_sb;
unsigned int l = strlen(symname) + 1;
struct inode *inode;
int err;
if (l > sb->s_blocksize)
return -ENAMETOOLONG;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inode = nilfs_new_inode(dir, S_IFLNK | 0777);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
/* slow symlink */
inode->i_op = &nilfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &nilfs_aops;
err = page_symlink(inode, symname, l);
if (err)
goto out_fail;
/* mark_inode_dirty(inode); */
/* page_symlink() do this */
err = nilfs_add_nondir(dentry, inode);
out:
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
out_fail:
drop_nlink(inode);
nilfs_mark_inode_dirty(inode);
unlock_new_inode(inode);
iput(inode);
goto out;
}
static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct inode *inode = d_inode(old_dentry);
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inode_set_ctime_current(inode);
inode_inc_link_count(inode);
ihold(inode);
err = nilfs_add_link(dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
err = nilfs_transaction_commit(dir->i_sb);
} else {
inode_dec_link_count(inode);
iput(inode);
nilfs_transaction_abort(dir->i_sb);
}
return err;
}
static int nilfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inc_nlink(dir);
inode = nilfs_new_inode(dir, S_IFDIR | mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_dir;
inode->i_op = &nilfs_dir_inode_operations;
inode->i_fop = &nilfs_dir_operations;
inode->i_mapping->a_ops = &nilfs_aops;
inc_nlink(inode);
err = nilfs_make_empty(inode, dir);
if (err)
goto out_fail;
err = nilfs_add_link(dentry, inode);
if (err)
goto out_fail;
nilfs_mark_inode_dirty(inode);
d_instantiate_new(dentry, inode);
out:
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
out_fail:
drop_nlink(inode);
drop_nlink(inode);
nilfs_mark_inode_dirty(inode);
unlock_new_inode(inode);
iput(inode);
out_dir:
drop_nlink(dir);
nilfs_mark_inode_dirty(dir);
goto out;
}
static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *inode;
struct nilfs_dir_entry *de;
struct folio *folio;
int err;
err = -ENOENT;
de = nilfs_find_entry(dir, &dentry->d_name, &folio);
if (!de)
goto out;
inode = d_inode(dentry);
err = -EIO;
if (le64_to_cpu(de->inode) != inode->i_ino)
goto out;
if (!inode->i_nlink) {
nilfs_warn(inode->i_sb,
"deleting nonexistent file (ino=%lu), %d",
inode->i_ino, inode->i_nlink);
set_nlink(inode, 1);
}
err = nilfs_delete_entry(de, folio);
folio_release_kmap(folio, de);
if (err)
goto out;
inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
drop_nlink(inode);
err = 0;
out:
return err;
}
static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
if (err)
return err;
err = nilfs_do_unlink(dir, dentry);
if (!err) {
nilfs_mark_inode_dirty(dir);
nilfs_mark_inode_dirty(d_inode(dentry));
err = nilfs_transaction_commit(dir->i_sb);
} else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
if (err)
return err;
err = -ENOTEMPTY;
if (nilfs_empty_dir(inode)) {
err = nilfs_do_unlink(dir, dentry);
if (!err) {
inode->i_size = 0;
drop_nlink(inode);
nilfs_mark_inode_dirty(inode);
drop_nlink(dir);
nilfs_mark_inode_dirty(dir);
}
}
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_rename(struct mnt_idmap *idmap,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
struct inode *old_inode = d_inode(old_dentry);
struct inode *new_inode = d_inode(new_dentry);
struct folio *dir_folio = NULL;
struct nilfs_dir_entry *dir_de = NULL;
struct folio *old_folio;
struct nilfs_dir_entry *old_de;
struct nilfs_transaction_info ti;
int err;
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
if (unlikely(err))
return err;
err = -ENOENT;
old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_folio);
if (!old_de)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = nilfs_dotdot(old_inode, &dir_folio);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct folio *new_folio;
struct nilfs_dir_entry *new_de;
err = -ENOTEMPTY;
if (dir_de && !nilfs_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_folio);
if (!new_de)
goto out_dir;
nilfs_set_link(new_dir, new_de, new_folio, old_inode);
folio_release_kmap(new_folio, new_de);
nilfs_mark_inode_dirty(new_dir);
inode_set_ctime_current(new_inode);
if (dir_de)
drop_nlink(new_inode);
drop_nlink(new_inode);
nilfs_mark_inode_dirty(new_inode);
} else {
err = nilfs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
if (dir_de) {
inc_nlink(new_dir);
nilfs_mark_inode_dirty(new_dir);
}
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
inode_set_ctime_current(old_inode);
nilfs_delete_entry(old_de, old_folio);
if (dir_de) {
nilfs_set_link(old_inode, dir_de, dir_folio, new_dir);
folio_release_kmap(dir_folio, dir_de);
drop_nlink(old_dir);
}
folio_release_kmap(old_folio, old_de);
nilfs_mark_inode_dirty(old_dir);
nilfs_mark_inode_dirty(old_inode);
err = nilfs_transaction_commit(old_dir->i_sb);
return err;
out_dir:
if (dir_de)
folio_release_kmap(dir_folio, dir_de);
out_old:
folio_release_kmap(old_folio, old_de);
out:
nilfs_transaction_abort(old_dir->i_sb);
return err;
}
/*
* Export operations
*/
static struct dentry *nilfs_get_parent(struct dentry *child)
{
unsigned long ino;
struct nilfs_root *root;
ino = nilfs_inode_by_name(d_inode(child), &dotdot_name);
if (!ino)
return ERR_PTR(-ENOENT);
root = NILFS_I(d_inode(child))->i_root;
return d_obtain_alias(nilfs_iget(child->d_sb, root, ino));
}
static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
u64 ino, u32 gen)
{
struct nilfs_root *root;
struct inode *inode;
if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
return ERR_PTR(-ESTALE);
root = nilfs_lookup_root(sb->s_fs_info, cno);
if (!root)
return ERR_PTR(-ESTALE);
inode = nilfs_iget(sb, root, ino);
nilfs_put_root(root);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (gen && inode->i_generation != gen) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return d_obtain_alias(inode);
}
static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
int fh_len, int fh_type)
{
struct nilfs_fid *fid = (struct nilfs_fid *)fh;
if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
(fh_type != FILEID_NILFS_WITH_PARENT &&
fh_type != FILEID_NILFS_WITHOUT_PARENT))
return NULL;
return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
}
static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
int fh_len, int fh_type)
{
struct nilfs_fid *fid = (struct nilfs_fid *)fh;
if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
fh_type != FILEID_NILFS_WITH_PARENT)
return NULL;
return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
}
static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
struct inode *parent)
{
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,
};
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