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OpenCloudOS-Kernel/fs/ufs/namei.c

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/*
* 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/smp_lock.h>
#include <linux/quotaops.h>
#include "ufs_fs.h"
#include "ufs.h"
#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->d_name);
if (ino) {
inode = ufs_iget(dir->i_sb, ino);
if (IS_ERR(inode)) {
unlock_kernel();
return ERR_CAST(inode);
}
}
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");
dquot_initialize(dir);
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;
dquot_initialize(dir);
inode = ufs_new_inode(dir, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, mode, rdev);
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;
dquot_initialize(dir);
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(UFS_I(inode)->i_u1.i_symlink, 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;
}
dquot_initialize(dir);
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;
dquot_initialize(dir);
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;
dquot_initialize(dir);
de = ufs_find_entry(dir, &dentry->d_name, &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;
dquot_initialize(old_dir);
dquot_initialize(new_dir);
old_de = ufs_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 = 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->d_name, &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,
};
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