kernel-ark/fs/ufs/namei.c
Arjan van de Ven c5ef1c42c5 [PATCH] mark struct inode_operations const 3
Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:46 -08:00

369 lines
7.8 KiB
C

/*
* linux/fs/ufs/namei.c
*
* Migration to usage of "page cache" on May 2006 by
* Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
*
* Copyright (C) 1998
* Daniel Pirkl <daniel.pirkl@email.cz>
* Charles University, Faculty of Mathematics and Physics
*
* from
*
* 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/time.h>
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/smp_lock.h>
#include "swab.h" /* will go away - see comment in mknod() */
#include "util.h"
static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = ufs_add_link(dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
iput(inode);
return err;
}
static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
{
struct inode * inode = NULL;
ino_t ino;
if (dentry->d_name.len > UFS_MAXNAMLEN)
return ERR_PTR(-ENAMETOOLONG);
lock_kernel();
ino = ufs_inode_by_name(dir, dentry);
if (ino) {
inode = iget(dir->i_sb, ino);
if (!inode) {
unlock_kernel();
return ERR_PTR(-EACCES);
}
}
unlock_kernel();
d_add(dentry, inode);
return NULL;
}
/*
* 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 ufs_create (struct inode * dir, struct dentry * dentry, int mode,
struct nameidata *nd)
{
struct inode *inode;
int err;
UFSD("BEGIN\n");
inode = ufs_new_inode(dir, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ufs_file_inode_operations;
inode->i_fop = &ufs_file_operations;
inode->i_mapping->a_ops = &ufs_aops;
mark_inode_dirty(inode);
lock_kernel();
err = ufs_add_nondir(dentry, inode);
unlock_kernel();
}
UFSD("END: err=%d\n", err);
return err;
}
static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
{
struct inode *inode;
int err;
if (!old_valid_dev(rdev))
return -EINVAL;
inode = ufs_new_inode(dir, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, mode, rdev);
/* NOTE: that'll go when we get wide dev_t */
ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
mark_inode_dirty(inode);
lock_kernel();
err = ufs_add_nondir(dentry, inode);
unlock_kernel();
}
return err;
}
static int ufs_symlink (struct inode * dir, struct dentry * dentry,
const char * symname)
{
struct super_block * sb = dir->i_sb;
int err = -ENAMETOOLONG;
unsigned l = strlen(symname)+1;
struct inode * inode;
if (l > sb->s_blocksize)
goto out_notlocked;
lock_kernel();
inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
/* slow symlink */
inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &ufs_aops;
err = page_symlink(inode, symname, l);
if (err)
goto out_fail;
} else {
/* fast symlink */
inode->i_op = &ufs_fast_symlink_inode_operations;
memcpy((char*)&UFS_I(inode)->i_u1.i_data,symname,l);
inode->i_size = l-1;
}
mark_inode_dirty(inode);
err = ufs_add_nondir(dentry, inode);
out:
unlock_kernel();
out_notlocked:
return err;
out_fail:
inode_dec_link_count(inode);
iput(inode);
goto out;
}
static int ufs_link (struct dentry * old_dentry, struct inode * dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
int error;
lock_kernel();
if (inode->i_nlink >= UFS_LINK_MAX) {
unlock_kernel();
return -EMLINK;
}
inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
atomic_inc(&inode->i_count);
error = ufs_add_nondir(dentry, inode);
unlock_kernel();
return error;
}
static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
{
struct inode * inode;
int err = -EMLINK;
if (dir->i_nlink >= UFS_LINK_MAX)
goto out;
lock_kernel();
inode_inc_link_count(dir);
inode = ufs_new_inode(dir, S_IFDIR|mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_dir;
inode->i_op = &ufs_dir_inode_operations;
inode->i_fop = &ufs_dir_operations;
inode->i_mapping->a_ops = &ufs_aops;
inode_inc_link_count(inode);
err = ufs_make_empty(inode, dir);
if (err)
goto out_fail;
err = ufs_add_link(dentry, inode);
if (err)
goto out_fail;
unlock_kernel();
d_instantiate(dentry, inode);
out:
return err;
out_fail:
inode_dec_link_count(inode);
inode_dec_link_count(inode);
iput (inode);
out_dir:
inode_dec_link_count(dir);
unlock_kernel();
goto out;
}
static int ufs_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
struct ufs_dir_entry *de;
struct page *page;
int err = -ENOENT;
de = ufs_find_entry(dir, dentry, &page);
if (!de)
goto out;
err = ufs_delete_entry(dir, de, page);
if (err)
goto out;
inode->i_ctime = dir->i_ctime;
inode_dec_link_count(inode);
err = 0;
out:
return err;
}
static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
int err= -ENOTEMPTY;
lock_kernel();
if (ufs_empty_dir (inode)) {
err = ufs_unlink(dir, dentry);
if (!err) {
inode->i_size = 0;
inode_dec_link_count(inode);
inode_dec_link_count(dir);
}
}
unlock_kernel();
return err;
}
static int ufs_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 ufs_dir_entry * dir_de = NULL;
struct page *old_page;
struct ufs_dir_entry *old_de;
int err = -ENOENT;
old_de = ufs_find_entry(old_dir, old_dentry, &old_page);
if (!old_de)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = ufs_dotdot(old_inode, &dir_page);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct page *new_page;
struct ufs_dir_entry *new_de;
err = -ENOTEMPTY;
if (dir_de && !ufs_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_de = ufs_find_entry(new_dir, new_dentry, &new_page);
if (!new_de)
goto out_dir;
inode_inc_link_count(old_inode);
ufs_set_link(new_dir, new_de, new_page, old_inode);
new_inode->i_ctime = CURRENT_TIME_SEC;
if (dir_de)
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
if (dir_de) {
err = -EMLINK;
if (new_dir->i_nlink >= UFS_LINK_MAX)
goto out_dir;
}
inode_inc_link_count(old_inode);
err = ufs_add_link(new_dentry, old_inode);
if (err) {
inode_dec_link_count(old_inode);
goto out_dir;
}
if (dir_de)
inode_inc_link_count(new_dir);
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
* inode_dec_link_count() will mark the inode dirty.
*/
old_inode->i_ctime = CURRENT_TIME_SEC;
ufs_delete_entry(old_dir, old_de, old_page);
inode_dec_link_count(old_inode);
if (dir_de) {
ufs_set_link(old_inode, dir_de, dir_page, new_dir);
inode_dec_link_count(old_dir);
}
return 0;
out_dir:
if (dir_de) {
kunmap(dir_page);
page_cache_release(dir_page);
}
out_old:
kunmap(old_page);
page_cache_release(old_page);
out:
return err;
}
const struct inode_operations ufs_dir_inode_operations = {
.create = ufs_create,
.lookup = ufs_lookup,
.link = ufs_link,
.unlink = ufs_unlink,
.symlink = ufs_symlink,
.mkdir = ufs_mkdir,
.rmdir = ufs_rmdir,
.mknod = ufs_mknod,
.rename = ufs_rename,
};