linux/fs/minix/namei.c
Arjan van de Ven 92e1d5be91 [PATCH] mark struct inode_operations const 2
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

305 lines
6.2 KiB
C

/*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include "minix.h"
static int add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = minix_add_link(dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
iput(inode);
return err;
}
static int minix_hash(struct dentry *dentry, struct qstr *qstr)
{
unsigned long hash;
int i;
const unsigned char *name;
i = minix_sb(dentry->d_inode->i_sb)->s_namelen;
if (i >= qstr->len)
return 0;
/* Truncate the name in place, avoids having to define a compare
function. */
qstr->len = i;
name = qstr->name;
hash = init_name_hash();
while (i--)
hash = partial_name_hash(*name++, hash);
qstr->hash = end_name_hash(hash);
return 0;
}
struct dentry_operations minix_dentry_operations = {
.d_hash = minix_hash,
};
static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
{
struct inode * inode = NULL;
ino_t ino;
dentry->d_op = dir->i_sb->s_root->d_op;
if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
return ERR_PTR(-ENAMETOOLONG);
ino = minix_inode_by_name(dentry);
if (ino) {
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
}
d_add(dentry, inode);
return NULL;
}
static int minix_mknod(struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
{
int error;
struct inode *inode;
if (!old_valid_dev(rdev))
return -EINVAL;
inode = minix_new_inode(dir, &error);
if (inode) {
inode->i_mode = mode;
minix_set_inode(inode, rdev);
mark_inode_dirty(inode);
error = add_nondir(dentry, inode);
}
return error;
}
static int minix_create(struct inode * dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
return minix_mknod(dir, dentry, mode, 0);
}
static int minix_symlink(struct inode * dir, struct dentry *dentry,
const char * symname)
{
int err = -ENAMETOOLONG;
int i = strlen(symname)+1;
struct inode * inode;
if (i > dir->i_sb->s_blocksize)
goto out;
inode = minix_new_inode(dir, &err);
if (!inode)
goto out;
inode->i_mode = S_IFLNK | 0777;
minix_set_inode(inode, 0);
err = page_symlink(inode, symname, i);
if (err)
goto out_fail;
err = add_nondir(dentry, inode);
out:
return err;
out_fail:
inode_dec_link_count(inode);
iput(inode);
goto out;
}
static int minix_link(struct dentry * old_dentry, struct inode * dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max)
return -EMLINK;
inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
atomic_inc(&inode->i_count);
return add_nondir(dentry, inode);
}
static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode)
{
struct inode * inode;
int err = -EMLINK;
if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max)
goto out;
inode_inc_link_count(dir);
inode = minix_new_inode(dir, &err);
if (!inode)
goto out_dir;
inode->i_mode = S_IFDIR | mode;
if (dir->i_mode & S_ISGID)
inode->i_mode |= S_ISGID;
minix_set_inode(inode, 0);
inode_inc_link_count(inode);
err = minix_make_empty(inode, dir);
if (err)
goto out_fail;
err = minix_add_link(dentry, inode);
if (err)
goto out_fail;
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);
goto out;
}
static int minix_unlink(struct inode * dir, struct dentry *dentry)
{
int err = -ENOENT;
struct inode * inode = dentry->d_inode;
struct page * page;
struct minix_dir_entry * de;
de = minix_find_entry(dentry, &page);
if (!de)
goto end_unlink;
err = minix_delete_entry(de, page);
if (err)
goto end_unlink;
inode->i_ctime = dir->i_ctime;
inode_dec_link_count(inode);
end_unlink:
return err;
}
static int minix_rmdir(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
int err = -ENOTEMPTY;
if (minix_empty_dir(inode)) {
err = minix_unlink(dir, dentry);
if (!err) {
inode_dec_link_count(dir);
inode_dec_link_count(inode);
}
}
return err;
}
static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir, struct dentry *new_dentry)
{
struct minix_sb_info * info = minix_sb(old_dir->i_sb);
struct inode * old_inode = old_dentry->d_inode;
struct inode * new_inode = new_dentry->d_inode;
struct page * dir_page = NULL;
struct minix_dir_entry * dir_de = NULL;
struct page * old_page;
struct minix_dir_entry * old_de;
int err = -ENOENT;
old_de = minix_find_entry(old_dentry, &old_page);
if (!old_de)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = minix_dotdot(old_inode, &dir_page);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct page * new_page;
struct minix_dir_entry * new_de;
err = -ENOTEMPTY;
if (dir_de && !minix_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_de = minix_find_entry(new_dentry, &new_page);
if (!new_de)
goto out_dir;
inode_inc_link_count(old_inode);
minix_set_link(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 >= info->s_link_max)
goto out_dir;
}
inode_inc_link_count(old_inode);
err = minix_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);
}
minix_delete_entry(old_de, old_page);
inode_dec_link_count(old_inode);
if (dir_de) {
minix_set_link(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;
}
/*
* directories can handle most operations...
*/
const struct inode_operations minix_dir_inode_operations = {
.create = minix_create,
.lookup = minix_lookup,
.link = minix_link,
.unlink = minix_unlink,
.symlink = minix_symlink,
.mkdir = minix_mkdir,
.rmdir = minix_rmdir,
.mknod = minix_mknod,
.rename = minix_rename,
.getattr = minix_getattr,
};