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