LXR linux-old/fs/intermezzo/journal

   1/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2 * vim:expandtab:shiftwidth=8:tabstop=8:
   3 *
   4 *  Copyright (C) 1998 Peter J. Braam <braam@clusterfs.com>
   5 *  Copyright (C) 2000 Red Hat, Inc.
   6 *  Copyright (C) 2000 Los Alamos National Laboratory
   7 *  Copyright (C) 2000 TurboLinux, Inc.
   8 *  Copyright (C) 2001 Mountain View Data, Inc.
   9 *  Copyright (C) 2001 Tacit Networks, Inc. <phil@off.net>
  10 *
  11 *   This file is part of InterMezzo, http://www.inter-mezzo.org.
  12 *
  13 *   InterMezzo is free software; you can redistribute it and/or
  14 *   modify it under the terms of version 2 of the GNU General Public
  15 *   License as published by the Free Software Foundation.
  16 *
  17 *   InterMezzo is distributed in the hope that it will be useful,
  18 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 *   GNU General Public License for more details.
  21 *
  22 *   You should have received a copy of the GNU General Public License
  23 *   along with InterMezzo; if not, write to the Free Software
  24 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25 */
  26
  27#include <linux/types.h>
  28#include <linux/param.h>
  29#include <linux/kernel.h>
  30#include <linux/sched.h>
  31#include <linux/fs.h>
  32#include <linux/slab.h>
  33#include <linux/vmalloc.h>
  34#include <linux/stat.h>
  35#include <linux/errno.h>
  36#include <linux/locks.h>
  37#include <asm/segment.h>
  38#include <asm/uaccess.h>
  39#include <linux/string.h>
  40#include <linux/smp_lock.h>
  41#if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  42#include <linux/jbd.h>
  43#include <linux/ext3_fs.h>
  44#include <linux/ext3_jbd.h>
  45#endif
  46
  47#include <linux/intermezzo_fs.h>
  48#include <linux/intermezzo_psdev.h>
  49
  50#if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  51
  52#define MAX_PATH_BLOCKS(inode) (PATH_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  53#define MAX_NAME_BLOCKS(inode) (NAME_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  54
  55/* space requirements: 
  56   presto_do_truncate: 
  57        used to truncate the KML forward to next fset->chunksize boundary
  58          - zero partial block
  59          - update inode
  60   presto_write_record: 
  61        write header (< one block) 
  62        write one path (< MAX_PATHLEN) 
  63        possibly write another path (< MAX_PATHLEN)
  64        write suffix (< one block) 
  65   presto_update_last_rcvd
  66        write one block
  67*/
  68
  69static loff_t presto_e3_freespace(struct presto_cache *cache,
  70                                         struct super_block *sb)
  71{
  72        loff_t freebl = le32_to_cpu(sb->u.ext3_sb.s_es->s_free_blocks_count);
  73        loff_t avail =   freebl - 
  74                le32_to_cpu(sb->u.ext3_sb.s_es->s_r_blocks_count);
  75        return (avail <<  EXT3_BLOCK_SIZE_BITS(sb));
  76}
  77
  78/* start the filesystem journal operations */
  79static void *presto_e3_trans_start(struct presto_file_set *fset, 
  80                                   struct inode *inode, 
  81                                   int op)
  82{
  83        int jblocks;
  84        int trunc_blks, one_path_blks, extra_path_blks, 
  85                extra_name_blks, lml_blks; 
  86        __u32 avail_kmlblocks;
  87        handle_t *handle;
  88
  89        if ( presto_no_journal(fset) ||
  90             strcmp(fset->fset_cache->cache_type, "ext3"))
  91          {
  92            CDEBUG(D_JOURNAL, "got cache_type \"%s\"\n",
  93                   fset->fset_cache->cache_type);
  94            return NULL;
  95          }
  96
  97        avail_kmlblocks = inode->i_sb->u.ext3_sb.s_es->s_free_blocks_count;
  98        
  99        if ( avail_kmlblocks < 3 ) {
 100                return ERR_PTR(-ENOSPC);
 101        }
 102        
 103        if (  (op != KML_OPCODE_UNLINK && op != KML_OPCODE_RMDIR)
 104              && avail_kmlblocks < 6 ) {
 105                return ERR_PTR(-ENOSPC);
 106        }            
 107
 108        /* Need journal space for:
 109             at least three writes to KML (two one block writes, one a path) 
 110             possibly a second name (unlink, rmdir)
 111             possibly a second path (symlink, rename)
 112             a one block write to the last rcvd file 
 113        */
 114
 115        trunc_blks = EXT3_DATA_TRANS_BLOCKS + 1; 
 116        one_path_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 3;
 117        lml_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 2;
 118        extra_path_blks = EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode); 
 119        extra_name_blks = EXT3_DATA_TRANS_BLOCKS + MAX_NAME_BLOCKS(inode); 
 120
 121        /* additional blocks appear for "two pathname" operations
 122           and operations involving the LML records 
 123        */
 124        switch (op) {
 125        case KML_OPCODE_TRUNC:
 126                jblocks = one_path_blks + extra_name_blks + trunc_blks
 127                        + EXT3_DELETE_TRANS_BLOCKS; 
 128                break;
 129        case KML_OPCODE_KML_TRUNC:
 130                /* Hopefully this is a little better, but I'm still mostly
 131                 * guessing here. */
 132                /* unlink 1 */
 133                jblocks = extra_name_blks + trunc_blks +
 134                        EXT3_DELETE_TRANS_BLOCKS + 2; 
 135
 136                /* unlink 2 */
 137                jblocks += extra_name_blks + trunc_blks +
 138                        EXT3_DELETE_TRANS_BLOCKS + 2; 
 139
 140                /* rename 1 */
 141                jblocks += 2 * extra_path_blks + trunc_blks + 
 142                        2 * EXT3_DATA_TRANS_BLOCKS + 2 + 3;
 143
 144                /* rename 2 */
 145                jblocks += 2 * extra_path_blks + trunc_blks + 
 146                        2 * EXT3_DATA_TRANS_BLOCKS + 2 + 3;
 147                break;
 148        case KML_OPCODE_RELEASE:
 149                /* 
 150                jblocks = one_path_blks + lml_blks + 2*trunc_blks; 
 151                */
 152                jblocks = one_path_blks; 
 153                break;
 154        case KML_OPCODE_SETATTR:
 155                jblocks = one_path_blks + trunc_blks + 1 ; 
 156                break;
 157        case KML_OPCODE_CREATE:
 158                jblocks = one_path_blks + trunc_blks 
 159                        + EXT3_DATA_TRANS_BLOCKS + 3 + 2; 
 160                break;
 161        case KML_OPCODE_LINK:
 162                jblocks = one_path_blks + trunc_blks 
 163                        + EXT3_DATA_TRANS_BLOCKS + 2; 
 164                break;
 165        case KML_OPCODE_UNLINK:
 166                jblocks = one_path_blks + extra_name_blks + trunc_blks
 167                        + EXT3_DELETE_TRANS_BLOCKS + 2; 
 168                break;
 169        case KML_OPCODE_SYMLINK:
 170                jblocks = one_path_blks + extra_path_blks + trunc_blks
 171                        + EXT3_DATA_TRANS_BLOCKS + 5; 
 172                break;
 173        case KML_OPCODE_MKDIR:
 174                jblocks = one_path_blks + trunc_blks
 175                        + EXT3_DATA_TRANS_BLOCKS + 4 + 2;
 176                break;
 177        case KML_OPCODE_RMDIR:
 178                jblocks = one_path_blks + extra_name_blks + trunc_blks
 179                        + EXT3_DELETE_TRANS_BLOCKS + 1; 
 180                break;
 181        case KML_OPCODE_MKNOD:
 182                jblocks = one_path_blks + trunc_blks + 
 183                        EXT3_DATA_TRANS_BLOCKS + 3 + 2;
 184                break;
 185        case KML_OPCODE_RENAME:
 186                jblocks = one_path_blks + extra_path_blks + trunc_blks + 
 187                        2 * EXT3_DATA_TRANS_BLOCKS + 2 + 3;
 188                break;
 189        case KML_OPCODE_WRITE:
 190                jblocks = one_path_blks; 
 191                /*  add this when we can wrap our transaction with 
 192                    that of ext3_file_write (ordered writes)
 193                    +  EXT3_DATA_TRANS_BLOCKS;
 194                */
 195                break;
 196        default:
 197                CDEBUG(D_JOURNAL, "invalid operation %d for journal\n", op);
 198                return NULL;
 199        }
 200
 201        CDEBUG(D_JOURNAL, "creating journal handle (%d blocks) for op %d\n",
 202               jblocks, op);
 203        /* journal_start/stop does not do its own locking while updating
 204         * the handle/transaction information. Hence we create our own
 205         * critical section to protect these calls. -SHP
 206         */
 207        lock_kernel();
 208        handle = journal_start(EXT3_JOURNAL(inode), jblocks);
 209        unlock_kernel();
 210        return handle;
 211}
 212
 213static void presto_e3_trans_commit(struct presto_file_set *fset, void *handle)
 214{
 215        if ( presto_no_journal(fset) || !handle)
 216                return;
 217
 218        /* See comments before journal_start above. -SHP */
 219        lock_kernel();
 220        journal_stop(handle);
 221        unlock_kernel();
 222}
 223
 224static void presto_e3_journal_file_data(struct inode *inode)
 225{
 226#ifdef EXT3_JOURNAL_DATA_FL
 227        inode->u.ext3_i.i_flags |= EXT3_JOURNAL_DATA_FL;
 228#else
 229#warning You must have a facility to enable journaled writes for recovery!
 230#endif
 231}
 232
 233/* The logic here is a slightly modified version of ext3/inode.c:block_to_path
 234 */
 235static int presto_e3_has_all_data(struct inode *inode)
 236{
 237        int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
 238        int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
 239        const long direct_blocks = EXT3_NDIR_BLOCKS,
 240                indirect_blocks = ptrs,
 241                double_blocks = (1 << (ptrs_bits * 2));
 242        long block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
 243                inode->i_sb->s_blocksize_bits;
 244
 245        ENTRY;
 246
 247        if (inode->i_size == 0) {
 248                EXIT;
 249                return 1;
 250        }
 251
 252        if (block < direct_blocks) {
 253                /* No indirect blocks, no problem. */
 254        } else if (block < indirect_blocks + direct_blocks) {
 255                block++;
 256        } else if (block < double_blocks + indirect_blocks + direct_blocks) {
 257                block += 2;
 258        } else if (((block - double_blocks - indirect_blocks - direct_blocks)
 259                    >> (ptrs_bits * 2)) < ptrs) {
 260                block += 3;
 261        }
 262
 263        block *= (inode->i_sb->s_blocksize / 512);
 264
 265        CDEBUG(D_CACHE, "Need %ld blocks, have %ld.\n", block, inode->i_blocks);
 266
 267        if (block > inode->i_blocks) {
 268                EXIT;
 269                return 0;
 270        }
 271
 272        EXIT;
 273        return 1;
 274}
 275
 276struct journal_ops presto_ext3_journal_ops = {
 277        .tr_all_data     = presto_e3_has_all_data,
 278        .tr_avail        = presto_e3_freespace,
 279        .tr_start        =  presto_e3_trans_start,
 280        .tr_commit       = presto_e3_trans_commit,
 281        .tr_journal_data = presto_e3_journal_file_data,
 282        .tr_ilookup      = presto_iget_ilookup
 283};
 284
 285#endif /* CONFIG_EXT3_FS */
 286