fs/ocfs2/alloc.h - linux - Git at Google

 /* -*- mode: c; c-basic-offset: 8; -*-
  * vim: noexpandtab sw=8 ts=8 sts=0:
  *
  * alloc.h
  *
  * Function prototypes
  *
  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public
  * License along with this program; if not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * Boston, MA 021110-1307, USA.
  */

 #ifndef OCFS2_ALLOC_H
 #define OCFS2_ALLOC_H


 /*
  * For xattr tree leaf, we limit the leaf byte size to be 64K.
  */
 #define OCFS2_MAX_XATTR_TREE_LEAF_SIZE 65536

 /*
  * ocfs2_extent_tree and ocfs2_extent_tree_operations are used to abstract
  * the b-tree operations in ocfs2. Now all the b-tree operations are not
  * limited to ocfs2_dinode only. Any data which need to allocate clusters
  * to store can use b-tree. And it only needs to implement its ocfs2_extent_tree
  * and operation.
  *
  * ocfs2_extent_tree becomes the first-class object for extent tree
  * manipulation.  Callers of the alloc.c code need to fill it via one of
  * the ocfs2_init_*_extent_tree() operations below.
  *
  * ocfs2_extent_tree contains info for the root of the b-tree, it must have a
  * root ocfs2_extent_list and a root_bh so that they can be used in the b-tree
  * functions.
  * ocfs2_extent_tree_operations abstract the normal operations we do for
  * the root of extent b-tree.
  */
 struct ocfs2_extent_tree_operations;
 struct ocfs2_extent_tree {
 	struct ocfs2_extent_tree_operations	*et_ops;
 	struct buffer_head			*et_root_bh;
 	struct ocfs2_extent_list		*et_root_el;
 	void					*et_object;
 	unsigned int				et_max_leaf_clusters;
 };

 /*
  * ocfs2_init_*_extent_tree() will fill an ocfs2_extent_tree from the
  * specified object buffer.
  */
 void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
 				   struct inode *inode,
 				   struct buffer_head *bh);
 void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
 				       struct inode *inode,
 				       struct buffer_head *bh);
 void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
 					struct inode *inode,
 					struct buffer_head *bh,
 					struct ocfs2_xattr_value_root *xv);

 /*
  * Read an extent block into *bh.  If *bh is NULL, a bh will be
  * allocated.  This is a cached read.  The extent block will be validated
  * with ocfs2_validate_extent_block().
  */
 int ocfs2_read_extent_block(struct inode *inode, u64 eb_blkno,
 			    struct buffer_head **bh);

 struct ocfs2_alloc_context;
 int ocfs2_insert_extent(struct ocfs2_super *osb,
 			handle_t *handle,
 			struct inode *inode,
 			struct ocfs2_extent_tree *et,
 			u32 cpos,
 			u64 start_blk,
 			u32 new_clusters,
 			u8 flags,
 			struct ocfs2_alloc_context *meta_ac);

 enum ocfs2_alloc_restarted {
 	RESTART_NONE = 0,
 	RESTART_TRANS,
 	RESTART_META
 };
 int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
 				struct inode *inode,
 				u32 *logical_offset,
 				u32 clusters_to_add,
 				int mark_unwritten,
 				struct ocfs2_extent_tree *et,
 				handle_t *handle,
 				struct ocfs2_alloc_context *data_ac,
 				struct ocfs2_alloc_context *meta_ac,
 				enum ocfs2_alloc_restarted *reason_ret);
 struct ocfs2_cached_dealloc_ctxt;
 int ocfs2_mark_extent_written(struct inode *inode,
 			      struct ocfs2_extent_tree *et,
 			      handle_t *handle, u32 cpos, u32 len, u32 phys,
 			      struct ocfs2_alloc_context *meta_ac,
 			      struct ocfs2_cached_dealloc_ctxt *dealloc);
 int ocfs2_remove_extent(struct inode *inode,
 			struct ocfs2_extent_tree *et,
 			u32 cpos, u32 len, handle_t *handle,
 			struct ocfs2_alloc_context *meta_ac,
 			struct ocfs2_cached_dealloc_ctxt *dealloc);
 int ocfs2_remove_btree_range(struct inode *inode,
 			     struct ocfs2_extent_tree *et,
 			     u32 cpos, u32 phys_cpos, u32 len,
 			     struct ocfs2_cached_dealloc_ctxt *dealloc);

 int ocfs2_num_free_extents(struct ocfs2_super *osb,
 			   struct inode *inode,
 			   struct ocfs2_extent_tree *et);

 /*
  * how many new metadata chunks would an allocation need at maximum?
  *
  * Please note that the caller must make sure that root_el is the root
  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
  * the result may be wrong.
  */
 static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
 {
 	/*
 	 * Rather than do all the work of determining how much we need
 	 * (involves a ton of reads and locks), just ask for the
 	 * maximal limit.  That's a tree depth shift.  So, one block for
 	 * level of the tree (current l_tree_depth), one block for the
 	 * new tree_depth==0 extent_block, and one block at the new
 	 * top-of-the tree.
 	 */
 	return le16_to_cpu(root_el->l_tree_depth) + 2;
 }

 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
 					 struct buffer_head *di_bh);

 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
 				       int cancel);
 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
 				      int slot_num,
 				      struct ocfs2_dinode **tl_copy);
 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
 					 struct ocfs2_dinode *tl_copy);
 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
 			      handle_t *handle,
 			      u64 start_blk,
 			      unsigned int num_clusters);
 int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);

 /*
  * Process local structure which describes the block unlinks done
  * during an operation. This is populated via
  * ocfs2_cache_block_dealloc().
  *
  * ocfs2_run_deallocs() should be called after the potentially
  * de-allocating routines. No journal handles should be open, and most
  * locks should have been dropped.
  */
 struct ocfs2_cached_dealloc_ctxt {
 	struct ocfs2_per_slot_free_list		*c_first_suballocator;
 	struct ocfs2_cached_block_free 		*c_global_allocator;
 };
 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
 {
 	c->c_first_suballocator = NULL;
 	c->c_global_allocator = NULL;
 }
 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
 				u64 blkno, unsigned int bit);
 static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
 {
 	return c->c_global_allocator != NULL;
 }
 int ocfs2_run_deallocs(struct ocfs2_super *osb,
 		       struct ocfs2_cached_dealloc_ctxt *ctxt);

 struct ocfs2_truncate_context {
 	struct ocfs2_cached_dealloc_ctxt tc_dealloc;
 	int tc_ext_alloc_locked; /* is it cluster locked? */
 	/* these get destroyed once it's passed to ocfs2_commit_truncate. */
 	struct buffer_head *tc_last_eb_bh;
 };

 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
 				  u64 range_start, u64 range_end);
 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
 			   struct inode *inode,
 			   struct buffer_head *fe_bh,
 			   struct ocfs2_truncate_context **tc);
 int ocfs2_commit_truncate(struct ocfs2_super *osb,
 			  struct inode *inode,
 			  struct buffer_head *fe_bh,
 			  struct ocfs2_truncate_context *tc);
 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
 			  unsigned int start, unsigned int end, int trunc);

 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
 		    u32 cpos, struct buffer_head **leaf_bh);
 int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);

 /*
  * Helper function to look at the # of clusters in an extent record.
  */
 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
 					      struct ocfs2_extent_rec *rec)
 {
 	/*
 	 * Cluster count in extent records is slightly different
 	 * between interior nodes and leaf nodes. This is to support
 	 * unwritten extents which need a flags field in leaf node
 	 * records, thus shrinking the available space for a clusters
 	 * field.
 	 */
 	if (el->l_tree_depth)
 		return le32_to_cpu(rec->e_int_clusters);
 	else
 		return le16_to_cpu(rec->e_leaf_clusters);
 }

 /*
  * This is only valid for leaf nodes, which are the only ones that can
  * have empty extents anyway.
  */
 static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
 {
 	return !rec->e_leaf_clusters;
 }

 #endif /* OCFS2_ALLOC_H */
	/* -- mode: c; c-basic-offset: 8; --
	* vim: noexpandtab sw=8 ts=8 sts=0:
	*
	* alloc.h
	*
	* Function prototypes
	*
	* Copyright (C) 2002, 2004 Oracle. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public
	* License along with this program; if not, write to the
	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	* Boston, MA 021110-1307, USA.
	*/

	#ifndef OCFS2_ALLOC_H
	#define OCFS2_ALLOC_H


	/*
	* For xattr tree leaf, we limit the leaf byte size to be 64K.
	*/
	#define OCFS2_MAX_XATTR_TREE_LEAF_SIZE 65536

	/*
	* ocfs2_extent_tree and ocfs2_extent_tree_operations are used to abstract
	* the b-tree operations in ocfs2. Now all the b-tree operations are not
	* limited to ocfs2_dinode only. Any data which need to allocate clusters
	* to store can use b-tree. And it only needs to implement its ocfs2_extent_tree
	* and operation.
	*
	* ocfs2_extent_tree becomes the first-class object for extent tree
	* manipulation. Callers of the alloc.c code need to fill it via one of
	* the ocfs2_init_*_extent_tree() operations below.
	*
	* ocfs2_extent_tree contains info for the root of the b-tree, it must have a
	* root ocfs2_extent_list and a root_bh so that they can be used in the b-tree
	* functions.
	* ocfs2_extent_tree_operations abstract the normal operations we do for
	* the root of extent b-tree.
	*/
	struct ocfs2_extent_tree_operations;
	struct ocfs2_extent_tree {
	struct ocfs2_extent_tree_operations *et_ops;
	struct buffer_head *et_root_bh;
	struct ocfs2_extent_list *et_root_el;
	void *et_object;
	unsigned int et_max_leaf_clusters;
	};

	/*
	* ocfs2_init_*_extent_tree() will fill an ocfs2_extent_tree from the
	* specified object buffer.
	*/
	void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
	struct inode *inode,
	struct buffer_head *bh);
	void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
	struct inode *inode,
	struct buffer_head *bh);
	void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
	struct inode *inode,
	struct buffer_head *bh,
	struct ocfs2_xattr_value_root *xv);

	/*
	* Read an extent block into bh. If bh is NULL, a bh will be
	* allocated. This is a cached read. The extent block will be validated
	* with ocfs2_validate_extent_block().
	*/
	int ocfs2_read_extent_block(struct inode *inode, u64 eb_blkno,
	struct buffer_head **bh);

	struct ocfs2_alloc_context;
	int ocfs2_insert_extent(struct ocfs2_super *osb,
	handle_t *handle,
	struct inode *inode,
	struct ocfs2_extent_tree *et,
	u32 cpos,
	u64 start_blk,
	u32 new_clusters,
	u8 flags,
	struct ocfs2_alloc_context *meta_ac);

	enum ocfs2_alloc_restarted {
	RESTART_NONE = 0,
	RESTART_TRANS,
	RESTART_META
	};
	int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
	struct inode *inode,
	u32 *logical_offset,
	u32 clusters_to_add,
	int mark_unwritten,
	struct ocfs2_extent_tree *et,
	handle_t *handle,
	struct ocfs2_alloc_context *data_ac,
	struct ocfs2_alloc_context *meta_ac,
	enum ocfs2_alloc_restarted *reason_ret);
	struct ocfs2_cached_dealloc_ctxt;
	int ocfs2_mark_extent_written(struct inode *inode,
	struct ocfs2_extent_tree *et,
	handle_t *handle, u32 cpos, u32 len, u32 phys,
	struct ocfs2_alloc_context *meta_ac,
	struct ocfs2_cached_dealloc_ctxt *dealloc);
	int ocfs2_remove_extent(struct inode *inode,
	struct ocfs2_extent_tree *et,
	u32 cpos, u32 len, handle_t *handle,
	struct ocfs2_alloc_context *meta_ac,
	struct ocfs2_cached_dealloc_ctxt *dealloc);
	int ocfs2_remove_btree_range(struct inode *inode,
	struct ocfs2_extent_tree *et,
	u32 cpos, u32 phys_cpos, u32 len,
	struct ocfs2_cached_dealloc_ctxt *dealloc);

	int ocfs2_num_free_extents(struct ocfs2_super *osb,
	struct inode *inode,
	struct ocfs2_extent_tree *et);

	/*
	* how many new metadata chunks would an allocation need at maximum?
	*
	* Please note that the caller must make sure that root_el is the root
	* of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
	* the result may be wrong.
	*/
	static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
	{
	/*
	* Rather than do all the work of determining how much we need
	* (involves a ton of reads and locks), just ask for the
	* maximal limit. That's a tree depth shift. So, one block for
	* level of the tree (current l_tree_depth), one block for the
	* new tree_depth==0 extent_block, and one block at the new
	* top-of-the tree.
	*/
	return le16_to_cpu(root_el->l_tree_depth) + 2;
	}

	void ocfs2_dinode_new_extent_list(struct inode inode, struct ocfs2_dinode di);
	void ocfs2_set_inode_data_inline(struct inode inode, struct ocfs2_dinode di);
	int ocfs2_convert_inline_data_to_extents(struct inode *inode,
	struct buffer_head *di_bh);

	int ocfs2_truncate_log_init(struct ocfs2_super *osb);
	void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
	void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
	int cancel);
	int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
	int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
	int slot_num,
	struct ocfs2_dinode **tl_copy);
	int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
	struct ocfs2_dinode *tl_copy);
	int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
	int ocfs2_truncate_log_append(struct ocfs2_super *osb,
	handle_t *handle,
	u64 start_blk,
	unsigned int num_clusters);
	int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);

	/*
	* Process local structure which describes the block unlinks done
	* during an operation. This is populated via
	* ocfs2_cache_block_dealloc().
	*
	* ocfs2_run_deallocs() should be called after the potentially
	* de-allocating routines. No journal handles should be open, and most
	* locks should have been dropped.
	*/
	struct ocfs2_cached_dealloc_ctxt {
	struct ocfs2_per_slot_free_list *c_first_suballocator;
	struct ocfs2_cached_block_free *c_global_allocator;
	};
	static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
	{
	c->c_first_suballocator = NULL;
	c->c_global_allocator = NULL;
	}
	int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
	u64 blkno, unsigned int bit);
	static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
	{
	return c->c_global_allocator != NULL;
	}
	int ocfs2_run_deallocs(struct ocfs2_super *osb,
	struct ocfs2_cached_dealloc_ctxt *ctxt);

	struct ocfs2_truncate_context {
	struct ocfs2_cached_dealloc_ctxt tc_dealloc;
	int tc_ext_alloc_locked; /* is it cluster locked? */
	/* these get destroyed once it's passed to ocfs2_commit_truncate. */
	struct buffer_head *tc_last_eb_bh;
	};

	int ocfs2_zero_range_for_truncate(struct inode inode, handle_t handle,
	u64 range_start, u64 range_end);
	int ocfs2_prepare_truncate(struct ocfs2_super *osb,
	struct inode *inode,
	struct buffer_head *fe_bh,
	struct ocfs2_truncate_context **tc);
	int ocfs2_commit_truncate(struct ocfs2_super *osb,
	struct inode *inode,
	struct buffer_head *fe_bh,
	struct ocfs2_truncate_context *tc);
	int ocfs2_truncate_inline(struct inode inode, struct buffer_head di_bh,
	unsigned int start, unsigned int end, int trunc);

	int ocfs2_find_leaf(struct inode inode, struct ocfs2_extent_list root_el,
	u32 cpos, struct buffer_head **leaf_bh);
	int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);

	/*
	* Helper function to look at the # of clusters in an extent record.
	*/
	static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
	struct ocfs2_extent_rec *rec)
	{
	/*
	* Cluster count in extent records is slightly different
	* between interior nodes and leaf nodes. This is to support
	* unwritten extents which need a flags field in leaf node
	* records, thus shrinking the available space for a clusters
	* field.
	*/
	if (el->l_tree_depth)
	return le32_to_cpu(rec->e_int_clusters);
	else
	return le16_to_cpu(rec->e_leaf_clusters);
	}

	/*
	* This is only valid for leaf nodes, which are the only ones that can
	* have empty extents anyway.
	*/
	static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
	{
	return !rec->e_leaf_clusters;
	}

	#endif /* OCFS2_ALLOC_H */