C++ BEFS_I函数代码示例

static struct dentry *
befs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct super_block *sb = dir->i_sb;
	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
	befs_off_t offset;
	int ret;
	int utfnamelen;
	char *utfname;
	const char *name = dentry->d_name.name;

	befs_debug(sb, "---> befs_lookup() "
		   "name %s inode %ld", dentry->d_name.name, dir->i_ino);

	/* Convert to UTF-8 */
	if (BEFS_SB(sb)->nls) {
		ret =
		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
		if (ret < 0) {
			befs_debug(sb, "<--- befs_lookup() ERROR");
			return ERR_PTR(ret);
		}
		ret = befs_btree_find(sb, ds, utfname, &offset);
		kfree(utfname);

	} else {
		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
	}

	if (ret == BEFS_BT_NOT_FOUND) {
		befs_debug(sb, "<--- befs_lookup() %s not found",
			   dentry->d_name.name);
		return ERR_PTR(-ENOENT);

	} else if (ret != BEFS_OK || offset == 0) {
		befs_warning(sb, "<--- befs_lookup() Error");
		return ERR_PTR(-ENODATA);
	}

	inode = iget(dir->i_sb, (ino_t) offset);
	if (!inode)
		return ERR_PTR(-EACCES);

	d_add(dentry, inode);

	befs_debug(sb, "<--- befs_lookup()");

	return NULL;
}

static struct dentry *
befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct inode *inode;
	struct super_block *sb = dir->i_sb;
	const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
	befs_off_t offset;
	int ret;
	int utfnamelen;
	char *utfname;
	const char *name = dentry->d_name.name;

	befs_debug(sb, "---> %s name %pd inode %ld", __func__,
		   dentry, dir->i_ino);

	/* Convert to UTF-8 */
	if (BEFS_SB(sb)->nls) {
		ret =
		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
		if (ret < 0) {
			befs_debug(sb, "<--- %s ERROR", __func__);
			return ERR_PTR(ret);
		}
		ret = befs_btree_find(sb, ds, utfname, &offset);
		kfree(utfname);

	} else {
		ret = befs_btree_find(sb, ds, name, &offset);
	}

	if (ret == BEFS_BT_NOT_FOUND) {
		befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
		d_add(dentry, NULL);
		return ERR_PTR(-ENOENT);

	} else if (ret != BEFS_OK || offset == 0) {
		befs_error(sb, "<--- %s Error", __func__);
		return ERR_PTR(-ENODATA);
	}

	inode = befs_iget(dir->i_sb, (ino_t) offset);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	d_add(dentry, inode);

	befs_debug(sb, "<--- %s", __func__);

	return NULL;
}

static int
befs_get_block(struct inode *inode, sector_t block,
	       struct buffer_head *bh_result, int create)
{
	struct super_block *sb = inode->i_sb;
	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
	befs_block_run run = BAD_IADDR;
	int res = 0;
	ulong disk_off;

	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
		   inode->i_ino, block);

	if (block < 0) {
		befs_error(sb, "befs_get_block() was asked for a block "
			   "number less than zero: block %ld in inode %lu",
			   block, inode->i_ino);
		return -EIO;
	}

	if (create) {
		befs_error(sb, "befs_get_block() was asked to write to "
			   "block %ld in inode %lu", block, inode->i_ino);
		return -EPERM;
	}

	res = befs_fblock2brun(sb, ds, block, &run);
	if (res != BEFS_OK) {
		befs_error(sb,
			   "<--- befs_get_block() for inode %lu, block "
			   "%ld ERROR", inode->i_ino, block);
		return -EFBIG;
	}

	disk_off = (ulong) iaddr2blockno(sb, &run);

	map_bh(bh_result, inode->i_sb, disk_off);

	befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
		   "disk address %lu", inode->i_ino, block, disk_off);

	return 0;
}

static int
befs_get_block(struct inode *inode, sector_t block,
	       struct buffer_head *bh_result, int create)
{
	struct super_block *sb = inode->i_sb;
	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
	befs_block_run run = BAD_IADDR;
	int res;
	ulong disk_off;

	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
		   (unsigned long)inode->i_ino, (long)block);
	if (create) {
		befs_error(sb, "befs_get_block() was asked to write to "
			   "block %ld in inode %lu", (long)block,
			   (unsigned long)inode->i_ino);
		return -EPERM;
	}

	res = befs_fblock2brun(sb, ds, block, &run);
	if (res != BEFS_OK) {
		befs_error(sb,
			   "<--- %s for inode %lu, block %ld ERROR",
			   __func__, (unsigned long)inode->i_ino,
			   (long)block);
		return -EFBIG;
	}

	disk_off = (ulong) iaddr2blockno(sb, &run);

	map_bh(bh_result, inode->i_sb, disk_off);

	befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
		  __func__, (unsigned long)inode->i_ino, (long)block,
		  (unsigned long)disk_off);

	return 0;
}

static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
{
	struct buffer_head *bh = NULL;
	befs_inode *raw_inode = NULL;

	befs_sb_info *befs_sb = BEFS_SB(sb);
	befs_inode_info *befs_ino = NULL;
	struct inode *inode;
	long ret = -EIO;

	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	befs_ino = BEFS_I(inode);

	/* convert from vfs's inode number to befs's inode number */
	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);

	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
		   befs_ino->i_inode_num.allocation_group,
		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);

	bh = befs_bread(sb, inode->i_ino);
	if (!bh) {
		befs_error(sb, "unable to read inode block - "
			   "inode = %lu", inode->i_ino);
		goto unacquire_none;
	}

	raw_inode = (befs_inode *) bh->b_data;

	befs_dump_inode(sb, raw_inode);

	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
		befs_error(sb, "Bad inode: %lu", inode->i_ino);
		goto unacquire_bh;
	}

	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);

	/*
	 * set uid and gid.  But since current BeOS is single user OS, so
	 * you can change by "uid" or "gid" options.
	 */   

	inode->i_uid = befs_sb->mount_opts.use_uid ?
		befs_sb->mount_opts.uid :
		make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
	inode->i_gid = befs_sb->mount_opts.use_gid ?
		befs_sb->mount_opts.gid :
		make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));

	set_nlink(inode, 1);

	/*
	 * BEFS's time is 64 bits, but current VFS is 32 bits...
	 * BEFS don't have access time. Nor inode change time. VFS
	 * doesn't have creation time.
	 * Also, the lower 16 bits of the last_modified_time and 
	 * create_time are just a counter to help ensure uniqueness
	 * for indexing purposes. (PFD, page 54)
	 */

	inode->i_mtime.tv_sec =
	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */	
	inode->i_ctime = inode->i_mtime;
	inode->i_atime = inode->i_mtime;

	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);

	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
		inode->i_size = 0;
		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
			BEFS_SYMLINK_LEN - 1);
		befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
	} else {
		int num_blks;

		befs_ino->i_data.ds =
		    fsds_to_cpu(sb, &raw_inode->data.datastream);

		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
		inode->i_blocks =
		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
		inode->i_size = befs_ino->i_data.ds.size;
	}

	inode->i_mapping->a_ops = &befs_aops;

	if (S_ISREG(inode->i_mode)) {
//.........这里部分代码省略.........

static void befs_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}

static int
befs_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	struct super_block *sb = inode->i_sb;
	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
	befs_off_t value;
	int result;
	size_t keysize;
	unsigned char d_type;
	char keybuf[BEFS_NAME_LEN + 1];
	const char *dirname = file->f_path.dentry->d_name.name;

	befs_debug(sb, "---> befs_readdir() "
		   "name %s, inode %ld, ctx->pos %Ld",
		   dirname, inode->i_ino, ctx->pos);

more:
	result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
				 keybuf, &keysize, &value);

	if (result == BEFS_ERR) {
		befs_debug(sb, "<--- befs_readdir() ERROR");
		befs_error(sb, "IO error reading %s (inode %lu)",
			   dirname, inode->i_ino);
		return -EIO;

	} else if (result == BEFS_BT_END) {
		befs_debug(sb, "<--- befs_readdir() END");
		return 0;

	} else if (result == BEFS_BT_EMPTY) {
		befs_debug(sb, "<--- befs_readdir() Empty directory");
		return 0;
	}

	d_type = DT_UNKNOWN;

	/* Convert to NLS */
	if (BEFS_SB(sb)->nls) {
		char *nlsname;
		int nlsnamelen;
		result =
		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
		if (result < 0) {
			befs_debug(sb, "<--- befs_readdir() ERROR");
			return result;
		}
		if (!dir_emit(ctx, nlsname, nlsnamelen,
				 (ino_t) value, d_type)) {
			kfree(nlsname);
			return 0;
		}
		kfree(nlsname);
	} else {
		if (!dir_emit(ctx, keybuf, keysize,
				 (ino_t) value, d_type))
			return 0;
	}
	ctx->pos++;
	goto more;

	befs_debug(sb, "<--- befs_readdir() pos %Ld", ctx->pos);

	return 0;
}

static void
befs_destroy_inode(struct inode *inode)
{
        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}

static int
befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct super_block *sb = inode->i_sb;
	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
	befs_off_t value;
	int result;
	size_t keysize;
	unsigned char d_type;
	char keybuf[BEFS_NAME_LEN + 1];
	char *nlsname;
	int nlsnamelen;
	const char *dirname = filp->f_dentry->d_name.name;

	befs_debug(sb, "---> befs_readdir() "
		   "name %s, inode %ld, filp->f_pos %Ld",
		   dirname, inode->i_ino, filp->f_pos);

	result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
				 keybuf, &keysize, &value);

	if (result == BEFS_ERR) {
		befs_debug(sb, "<--- befs_readdir() ERROR");
		befs_error(sb, "IO error reading %s (inode %lu)",
			   dirname, inode->i_ino);
		return -EIO;

	} else if (result == BEFS_BT_END) {
		befs_debug(sb, "<--- befs_readdir() END");
		return 0;

	} else if (result == BEFS_BT_EMPTY) {
		befs_debug(sb, "<--- befs_readdir() Empty directory");
		return 0;
	}

	d_type = DT_UNKNOWN;

	/* Convert to NLS */
	if (BEFS_SB(sb)->nls) {
		result =
		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
		if (result < 0) {
			befs_debug(sb, "<--- befs_readdir() ERROR");
			return result;
		}
		result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
				 (ino_t) value, d_type);
		kfree(nlsname);

	} else {
		result = filldir(dirent, keybuf, keysize, filp->f_pos,
				 (ino_t) value, d_type);
	}

	filp->f_pos++;

	befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);

	return 0;
}

static void befs_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	INIT_LIST_HEAD(&inode->i_dentry);
        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}