xref: /openbmc/linux/fs/ocfs2/alloc.h (revision 2b604351)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * alloc.h
5  *
6  * Function prototypes
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #ifndef OCFS2_ALLOC_H
27 #define OCFS2_ALLOC_H
28 
29 struct ocfs2_alloc_context;
30 int ocfs2_insert_extent(struct ocfs2_super *osb,
31 			handle_t *handle,
32 			struct inode *inode,
33 			struct buffer_head *fe_bh,
34 			u32 cpos,
35 			u64 start_blk,
36 			u32 new_clusters,
37 			struct ocfs2_alloc_context *meta_ac);
38 int ocfs2_num_free_extents(struct ocfs2_super *osb,
39 			   struct inode *inode,
40 			   struct ocfs2_dinode *fe);
41 /* how many new metadata chunks would an allocation need at maximum? */
42 static inline int ocfs2_extend_meta_needed(struct ocfs2_dinode *fe)
43 {
44 	/*
45 	 * Rather than do all the work of determining how much we need
46 	 * (involves a ton of reads and locks), just ask for the
47 	 * maximal limit.  That's a tree depth shift.  So, one block for
48 	 * level of the tree (current l_tree_depth), one block for the
49 	 * new tree_depth==0 extent_block, and one block at the new
50 	 * top-of-the tree.
51 	 */
52 	return le16_to_cpu(fe->id2.i_list.l_tree_depth) + 2;
53 }
54 
55 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
56 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
57 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
58 				       int cancel);
59 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
60 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
61 				      int slot_num,
62 				      struct ocfs2_dinode **tl_copy);
63 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
64 					 struct ocfs2_dinode *tl_copy);
65 
66 /*
67  * Process local structure which describes the block unlinks done
68  * during an operation. This is populated via
69  * ocfs2_cache_block_dealloc().
70  *
71  * ocfs2_run_deallocs() should be called after the potentially
72  * de-allocating routines. No journal handles should be open, and most
73  * locks should have been dropped.
74  */
75 struct ocfs2_cached_dealloc_ctxt {
76 	struct ocfs2_per_slot_free_list		*c_first_suballocator;
77 };
78 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
79 {
80 	c->c_first_suballocator = NULL;
81 }
82 int ocfs2_run_deallocs(struct ocfs2_super *osb,
83 		       struct ocfs2_cached_dealloc_ctxt *ctxt);
84 
85 struct ocfs2_truncate_context {
86 	struct inode *tc_ext_alloc_inode;
87 	struct buffer_head *tc_ext_alloc_bh;
88 	int tc_ext_alloc_locked; /* is it cluster locked? */
89 	/* these get destroyed once it's passed to ocfs2_commit_truncate. */
90 	struct buffer_head *tc_last_eb_bh;
91 };
92 
93 int ocfs2_zero_tail_for_truncate(struct inode *inode, handle_t *handle,
94 				 u64 new_i_size);
95 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
96 			   struct inode *inode,
97 			   struct buffer_head *fe_bh,
98 			   struct ocfs2_truncate_context **tc);
99 int ocfs2_commit_truncate(struct ocfs2_super *osb,
100 			  struct inode *inode,
101 			  struct buffer_head *fe_bh,
102 			  struct ocfs2_truncate_context *tc);
103 
104 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
105 		    u32 cpos, struct buffer_head **leaf_bh);
106 
107 /*
108  * Helper function to look at the # of clusters in an extent record.
109  */
110 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
111 					      struct ocfs2_extent_rec *rec)
112 {
113 	/*
114 	 * Cluster count in extent records is slightly different
115 	 * between interior nodes and leaf nodes. This is to support
116 	 * unwritten extents which need a flags field in leaf node
117 	 * records, thus shrinking the available space for a clusters
118 	 * field.
119 	 */
120 	if (el->l_tree_depth)
121 		return le32_to_cpu(rec->e_int_clusters);
122 	else
123 		return le16_to_cpu(rec->e_leaf_clusters);
124 }
125 
126 #endif /* OCFS2_ALLOC_H */
127