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root/fs/ufs/namei.c

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DEFINITIONS

This source file includes following definitions.
  1. ufs_add_nondir
  2. ufs_lookup
  3. ufs_create
  4. ufs_mknod
  5. ufs_symlink
  6. ufs_link
  7. ufs_mkdir
  8. ufs_unlink
  9. ufs_rmdir
  10. ufs_rename

/*
 * 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 "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);
        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");
        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);
                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,
};

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