- 根目录:
- fs
- nilfs2
- namei.c
/*
* namei.c - NILFS pathname lookup operations.
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>,
* Ryusuke Konishi <ryusuke@osrg.net>
*/
/*
* linux/fs/ext2/namei.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* 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 (davem@caip.rutgers.edu), 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(dentry, inode);
return 0;
}
inode_dec_link_count(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 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 inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err;
if (!new_valid_dev(rdev))
return -EINVAL;
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 inode *dir, struct dentry *dentry,
const char *symname)
{
struct nilfs_transaction_info ti;
struct super_block *sb = dir->i_sb;
unsigned 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 | S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
/* slow symlink */
inode->i_op = &nilfs_symlink_inode_operations;
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);
iput(inode);
goto out;
}
static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
struct nilfs_transaction_info ti;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
inode->i_ctime = CURRENT_TIME;
inode_inc_link_count(inode);
ihold(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_mkdir(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(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);
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 page *page;
int err;
err = -ENOENT;
de = nilfs_find_entry(dir, &dentry->d_name, &page);
if (!de)
goto out;
inode = dentry->d_inode;
err = -EIO;
if (le64_to_cpu(de->inode) != inode->i_ino)
goto out;
if (!inode->i_nlink) {
nilfs_warning(inode->i_sb, __func__,
"deleting nonexistent file (%lu), %d\n",
inode->i_ino, inode->i_nlink);
set_nlink(inode, 1);
}
err = nilfs_delete_entry(de, page);
if (err)
goto out;
inode->i_ctime = dir->i_ctime;
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(dentry->d_inode);
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 = dentry->d_inode;
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 inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct inode *old_inode = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
struct page *dir_page = NULL;
struct nilfs_dir_entry *dir_de = NULL;
struct page *old_page;
struct nilfs_dir_entry *old_de;
struct nilfs_transaction_info ti;
int err;
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_page);
if (!old_de)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = nilfs_dotdot(old_inode, &dir_page);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct page *new_page;
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_page);
if (!new_de)
goto out_dir;
nilfs_set_link(new_dir, new_de, new_page, old_inode);
nilfs_mark_inode_dirty(new_dir);
new_inode->i_ctime = CURRENT_TIME;
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.
*/
old_inode->i_ctime = CURRENT_TIME;
nilfs_delete_entry(old_de, old_page);
if (dir_de) {
nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
drop_nlink(old_dir);
}
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) {
kunmap(dir_page);
page_cache_release(dir_page);
}
out_old:
kunmap(old_page);
page_cache_release(old_page);
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 inode *inode;
struct qstr dotdot = QSTR_INIT("..", 2);
struct nilfs_root *root;
ino = nilfs_inode_by_name(child->d_inode, &dotdot);
if (!ino)
return ERR_PTR(-ENOENT);
root = NILFS_I(child->d_inode)->i_root;
inode = nilfs_iget(child->d_inode->i_sb, root, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
return d_obtain_alias(inode);
}
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_len != NILFS_FID_SIZE_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,
};
const struct inode_operations nilfs_special_inode_operations = {
.setattr = nilfs_setattr,
.permission = nilfs_permission,
};
const struct inode_operations nilfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_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,
};