linux/fs/nilfs2/namei.c
Ryusuke Konishi e3154e9748 nilfs2: get rid of nilfs_sb_info structure
This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:54:26 +09:00

594 lines
13 KiB
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, struct nameidata *nd)
{
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 = NULL;
if (ino) {
inode = nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
}
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, int mode,
struct nameidata *nd)
{
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, int 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;
if (inode->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
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, int mode)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err;
if (dir->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
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);
inode->i_nlink = 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 {
if (dir_de) {
err = -EMLINK;
if (new_dir->i_nlink >= NILFS_LINK_MAX)
goto out_dir;
}
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 = {.name = "..", .len = 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 dentry *dentry, __u32 *fh, int *lenp,
int connectable)
{
struct nilfs_fid *fid = (struct nilfs_fid *)fh;
struct inode *inode = dentry->d_inode;
struct nilfs_root *root = NILFS_I(inode)->i_root;
int type;
if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE ||
(connectable && *lenp < NILFS_FID_SIZE_CONNECTABLE))
return 255;
fid->cno = root->cno;
fid->ino = inode->i_ino;
fid->gen = inode->i_generation;
if (connectable && !S_ISDIR(inode->i_mode)) {
struct inode *parent;
spin_lock(&dentry->d_lock);
parent = dentry->d_parent->d_inode;
fid->parent_ino = parent->i_ino;
fid->parent_gen = parent->i_generation;
spin_unlock(&dentry->d_lock);
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,
};