release/src-rt-6.x/linux/linux-2.6/fs/ocfs2/alloc.h

   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 struct ocfs2_truncate_context {
  67         struct inode *tc_ext_alloc_inode;
  68         struct buffer_head *tc_ext_alloc_bh;
  69         int tc_ext_alloc_locked; /* is it cluster locked? */
  70         /* these get destroyed once it's passed to ocfs2_commit_truncate. */
  71         struct buffer_head *tc_last_eb_bh;
  72 };
  73
  74 int ocfs2_zero_tail_for_truncate(struct inode *inode, handle_t *handle,
  75                                  u64 new_i_size);
  76 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
  77                            struct inode *inode,
  78                            struct buffer_head *fe_bh,
  79                            struct ocfs2_truncate_context **tc);
  80 int ocfs2_commit_truncate(struct ocfs2_super *osb,
  81                           struct inode *inode,
  82                           struct buffer_head *fe_bh,
  83                           struct ocfs2_truncate_context *tc);
  84
  85 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
  86                     u32 cpos, struct buffer_head **leaf_bh);
  87
  88 /*
  89  * Helper function to look at the # of clusters in an extent record.
  90  */
  91 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
  92                                               struct ocfs2_extent_rec *rec)
  93 {
  94         /*
  95          * Cluster count in extent records is slightly different
  96          * between interior nodes and leaf nodes. This is to support
  97          * unwritten extents which need a flags field in leaf node
  98          * records, thus shrinking the available space for a clusters
  99          * field.
 100          */
 101         if (el->l_tree_depth)
 102                 return le32_to_cpu(rec->e_int_clusters);
 103         else
 104                 return le16_to_cpu(rec->e_leaf_clusters);
 105 }
 106
 107 #endif /* OCFS2_ALLOC_H */