namei.c

linux 内核源代码

		    NAME_NOT_FOUND) {
			reiserfs_warning(dir->i_sb,
					 "vs-7032: reiserfs_add_entry: "
					 "entry with this key (%K) already exists",
					 &entry_key);

			if (buffer != small_buf)
				kfree(buffer);
			pathrelse(&path);
			return -EBUSY;
		}
	}

	/* perform the insertion of the entry that we have prepared */
	retval =
	    reiserfs_paste_into_item(th, &path, &entry_key, dir, buffer,
				     paste_size);
	if (buffer != small_buf)
		kfree(buffer);
	if (retval) {
		reiserfs_check_path(&path);
		return retval;
	}

	dir->i_size += paste_size;
	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
	if (!S_ISDIR(inode->i_mode) && visible)
		// reiserfs_mkdir or reiserfs_rename will do that by itself
		reiserfs_update_sd(th, dir);

	reiserfs_check_path(&path);
	return 0;
}

/* quota utility function, call if you've had to abort after calling
** new_inode_init, and have not called reiserfs_new_inode yet.
** This should only be called on inodes that do not have stat data
** inserted into the tree yet.
*/
static int drop_new_inode(struct inode *inode)
{
	DQUOT_DROP(inode);
	make_bad_inode(inode);
	inode->i_flags |= S_NOQUOTA;
	iput(inode);
	return 0;
}

/* utility function that does setup for reiserfs_new_inode.  
** DQUOT_INIT needs lots of credits so it's better to have it
** outside of a transaction, so we had to pull some bits of
** reiserfs_new_inode out into this func.
*/
static int new_inode_init(struct inode *inode, struct inode *dir, int mode)
{

	/* the quota init calls have to know who to charge the quota to, so
	 ** we have to set uid and gid here
	 */
	inode->i_uid = current->fsuid;
	inode->i_mode = mode;
	/* Make inode invalid - just in case we are going to drop it before
	 * the initialization happens */
	INODE_PKEY(inode)->k_objectid = 0;

	if (dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;
		if (S_ISDIR(mode))
			inode->i_mode |= S_ISGID;
	} else {
		inode->i_gid = current->fsgid;
	}
	DQUOT_INIT(inode);
	return 0;
}

static int reiserfs_create(struct inode *dir, struct dentry *dentry, int mode,
			   struct nameidata *nd)
{
	int retval;
	struct inode *inode;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
	struct reiserfs_transaction_handle th;
	int locked;

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	locked = reiserfs_cache_default_acl(dir);

	reiserfs_write_lock(dir->i_sb);

	if (locked)
		reiserfs_write_lock_xattrs(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode);
	if (retval)
		goto out_failed;

	if (locked) {
		reiserfs_write_unlock_xattrs(dir->i_sb);
		locked = 0;
	}

	inode->i_op = &reiserfs_file_inode_operations;
	inode->i_fop = &reiserfs_file_operations;
	inode->i_mapping->a_ops = &reiserfs_address_space_operations;

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink--;
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		iput(inode);
		goto out_failed;
	}
	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	if (locked)
		reiserfs_write_unlock_xattrs(dir->i_sb);
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
			  dev_t rdev)
{
	int retval;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
	int locked;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	locked = reiserfs_cache_default_acl(dir);

	reiserfs_write_lock(dir->i_sb);

	if (locked)
		reiserfs_write_lock_xattrs(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode);
	if (retval) {
		goto out_failed;
	}

	if (locked) {
		reiserfs_write_unlock_xattrs(dir->i_sb);
		locked = 0;
	}

	inode->i_op = &reiserfs_special_inode_operations;
	init_special_inode(inode, inode->i_mode, rdev);

	//FIXME: needed for block and char devices only
	reiserfs_update_sd(&th, inode);

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink--;
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		iput(inode);
		goto out_failed;
	}

	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	if (locked)
		reiserfs_write_unlock_xattrs(dir->i_sb);
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	int retval;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
	int locked;

#ifdef DISPLACE_NEW_PACKING_LOCALITIES
	/* set flag that new packing locality created and new blocks for the content     * of that directory are not displaced yet */
	REISERFS_I(dir)->new_packing_locality = 1;
#endif
	mode = S_IFDIR | mode;
	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	locked = reiserfs_cache_default_acl(dir);

	reiserfs_write_lock(dir->i_sb);
	if (locked)
		reiserfs_write_lock_xattrs(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	/* inc the link count now, so another writer doesn't overflow it while
	 ** we sleep later on.
	 */
	INC_DIR_INODE_NLINK(dir)

	    retval = reiserfs_new_inode(&th, dir, mode, NULL /*symlink */ ,
					old_format_only(dir->i_sb) ?
					EMPTY_DIR_SIZE_V1 : EMPTY_DIR_SIZE,
					dentry, inode);
	if (retval) {
		dir->i_nlink--;
		goto out_failed;
	}

	if (locked) {
		reiserfs_write_unlock_xattrs(dir->i_sb);
		locked = 0;
	}

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	inode->i_op = &reiserfs_dir_inode_operations;
	inode->i_fop = &reiserfs_dir_operations;

	// note, _this_ add_entry will not update dir's stat data
	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink = 0;
		DEC_DIR_INODE_NLINK(dir);
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		iput(inode);
		goto out_failed;
	}
	// the above add_entry did not update dir's stat data
	reiserfs_update_sd(&th, dir);

	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);
      out_failed:
	if (locked)
		reiserfs_write_unlock_xattrs(dir->i_sb);
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static inline int reiserfs_empty_dir(struct inode *inode)
{
	/* we can cheat because an old format dir cannot have
	 ** EMPTY_DIR_SIZE, and a new format dir cannot have
	 ** EMPTY_DIR_SIZE_V1.  So, if the inode is either size, 
	 ** regardless of disk format version, the directory is empty.
	 */
	if (inode->i_size != EMPTY_DIR_SIZE &&
	    inode->i_size != EMPTY_DIR_SIZE_V1) {
		return 0;
	}
	return 1;
}

static int reiserfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int retval, err;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	int jbegin_count;
	INITIALIZE_PATH(path);
	struct reiserfs_dir_entry de;

	/* we will be doing 2 balancings and update 2 stat data, we change quotas
	 * of the owner of the directory and of the owner of the parent directory.
	 * The quota structure is possibly deleted only on last iput => outside
	 * of this transaction */
	jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 + 2 +
	    4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);

	reiserfs_write_lock(dir->i_sb);
	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval)
		goto out_rmdir;

	de.de_gen_number_bit_string = NULL;
	if ((retval =
	     reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
				 &path, &de)) == NAME_NOT_FOUND) {
		retval = -ENOENT;
		goto end_rmdir;
	} else if (retval == IO_ERROR) {
		retval = -EIO;
		goto end_rmdir;
	}

	inode = dentry->d_inode;

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	if (de.de_objectid != inode->i_ino) {
		// FIXME: compare key of an object and a key found in the
		// entry
		retval = -EIO;
		goto end_rmdir;
	}
	if (!reiserfs_empty_dir(inode)) {
		retval = -ENOTEMPTY;
		goto end_rmdir;
	}

	/* cut entry from dir directory */
	retval = reiserfs_cut_from_item(&th, &path, &(de.de_entry_key), dir, NULL,	/* page */
					0 /*new file size - not used here */ );
	if (retval < 0)
		goto end_rmdir;

	if (inode->i_nlink != 2 && inode->i_nlink != 1)
		reiserfs_warning(inode->i_sb, "%s: empty directory has nlink "
				 "!= 2 (%d)", __FUNCTION__, inode->i_nlink);

	clear_nlink(inode);
	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	reiserfs_update_sd(&th, inode);

	DEC_DIR_INODE_NLINK(dir)
	    dir->i_size -= (DEH_SIZE + de.de_entrylen);
	reiserfs_update_sd(&th, dir);

	/* prevent empty directory from getting lost */
	add_save_link(&th, inode, 0 /* not truncate */ );

	retval = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_check_path(&path);
      out_rmdir:
	reiserfs_write_unlock(dir->i_sb);
	return retval;

      end_rmdir:
	/* we must release path, because we did not call
	   reiserfs_cut_from_item, or reiserfs_cut_from_item does not
	   release path if operation was not complete */
	pathrelse(&path);
	err = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_write_unlock(dir->i_sb);
	return err ? err : retval;
}

static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
{
	int retval, err;
	struct inode *inode;
	struct reiserfs_dir_entry de;
	INITIALIZE_PATH(path);
	struct reiserfs_transaction_handle th;
	int jbegin_count;
	unsigned long savelink;

	inode = dentry->d_inode;

	/* in this transaction we can be doing at max two balancings and update
	 * two stat datas, we change quotas of the owner of the directory and of
	 * the owner of the parent directory. The quota structure is possibly
	 * deleted only on iput => outside of this transaction */
	jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 + 2 +
	    4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);

	reiserfs_write_lock(dir->i_sb);
	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval)
		goto out_unlink;

	de.de_gen_number_bit_string = NULL;
	if ((retval =
	     reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
				 &path, &de)) == NAME_NOT_FOUND) {
		retval = -ENOENT;
		goto end_unlink;
	} else if (retval == IO_ERROR) {
		retval = -EIO;
		goto end_unlink;
	}

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	if (de.de_objectid != inode->i_ino) {
		// FIXME: compare key of an object and a key found in the
		// entry
		retval = -EIO;
		goto end_unlink;
	}

	if (!inode->i_nlink) {
		reiserfs_warning(inode->i_sb, "%s: deleting nonexistent file "
				 "(%s:%lu), %d", __FUNCTION__,
				 reiserfs_bdevname(inode->i_sb), inode->i_ino,
				 inode->i_nlink);
		inode->i_nlink = 1;
	}

	drop_nlink(inode);

	/*
	 * we schedule before doing the add_save_link call, save the link
	 * count so we don't race
	 */
	savelink = inode->i_nlink;

	retval =
	    reiserfs_cut_from_item(&th, &path, &(de.de_entry_key), dir, NULL,
				   0);
	if (retval < 0) {
		inc_nlink(inode);
		goto end_unlink;
	}
	inode->i_ctime = CURRENT_TIME_SEC;
	reiserfs_update_sd(&th, inode);

	dir->i_size -= (de.de_entrylen + DEH_SIZE);
	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	reiserfs_update_sd(&th, dir);

	if (!savelink)
		/* prevent file from getting lost */
		add_save_link(&th, inode, 0 /* not truncate */ );

	retval = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_check_path(&path);
	reiserfs_write_unlock(dir->i_sb);
	return retval;

      end_unlink:
	pathrelse(&path);
	err = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_check_path(&path);
	if (err)
		retval = err;
      out_unlink:
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int reiserfs_symlink(struct inode *parent_dir,
			    struct dentry *dentry, const char *symname)
{
	int retval;
	struct inode *inode;
	char *name;
	int item_len;
	struct reiserfs_transaction_handle th;
	int mode = S_IFLNK | S_IRWXUGO;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(parent_dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(parent_dir->i_sb));

	if (!(inode = new_inode(parent_dir->i_sb))) {