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root/fs/minix/namei.c

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DEFINITIONS

This source file includes following definitions.
  1. add_nondir
  2. minix_lookup
  3. minix_mknod
  4. minix_create
  5. minix_symlink
  6. minix_link
  7. minix_mkdir
  8. minix_unlink
  9. minix_rmdir
  10. minix_rename

/*
 *  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 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 = minix_iget(dir->i_sb, ino);
                if (IS_ERR(inode))
                        return ERR_CAST(inode);
        }
        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,
};

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