fs/ocfs2/journal.h

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * journal.h
   5  *
   6  * Defines journalling api and structures.
   7  *
   8  * Copyright (C) 2003, 2005 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_JOURNAL_H
  27 #define OCFS2_JOURNAL_H
  28
  29 #include <linux/fs.h>
  30 #include <linux/jbd.h>
  31
  32 enum ocfs2_journal_state {
  33         OCFS2_JOURNAL_FREE = 0,
  34         OCFS2_JOURNAL_LOADED,
  35         OCFS2_JOURNAL_IN_SHUTDOWN,
  36 };
  37
  38 struct ocfs2_super;
  39 struct ocfs2_dinode;
  40
  41 struct ocfs2_journal {
  42         enum ocfs2_journal_state   j_state;    /* Journals current state   */
  43
  44         journal_t                 *j_journal; /* The kernels journal type */
  45         struct inode              *j_inode;   /* Kernel inode pointing to
  46                                                * this journal             */
  47         struct ocfs2_super        *j_osb;     /* pointer to the super
  48                                                * block for the node
  49                                                * we're currently
  50                                                * running on -- not
  51                                                * necessarily the super
  52                                                * block from the node
  53                                                * which we usually run
  54                                                * from (recovery,
  55                                                * etc)                     */
  56         struct buffer_head        *j_bh;      /* Journal disk inode block */
  57         atomic_t                  j_num_trans; /* Number of transactions
  58                                                 * currently in the system. */
  59         unsigned long             j_trans_id;
  60         struct rw_semaphore       j_trans_barrier;
  61         wait_queue_head_t         j_checkpointed;
  62
  63         spinlock_t                j_lock;
  64         struct list_head          j_la_cleanups;
  65         struct work_struct        j_recovery_work;
  66 };
  67
  68 extern spinlock_t trans_inc_lock;
  69
  70 /* wrap j_trans_id so we never have it equal to zero. */
  71 static inline unsigned long ocfs2_inc_trans_id(struct ocfs2_journal *j)
  72 {
  73         unsigned long old_id;
  74         spin_lock(&trans_inc_lock);
  75         old_id = j->j_trans_id++;
  76         if (unlikely(!j->j_trans_id))
  77                 j->j_trans_id = 1;
  78         spin_unlock(&trans_inc_lock);
  79         return old_id;
  80 }
  81
  82 static inline void ocfs2_set_inode_lock_trans(struct ocfs2_journal *journal,
  83                                               struct inode *inode)
  84 {
  85         spin_lock(&trans_inc_lock);
  86         OCFS2_I(inode)->ip_last_trans = journal->j_trans_id;
  87         spin_unlock(&trans_inc_lock);
  88 }
  89
  90 /* Used to figure out whether it's safe to drop a metadata lock on an
  91  * inode. Returns true if all the inodes changes have been
  92  * checkpointed to disk. You should be holding the spinlock on the
  93  * metadata lock while calling this to be sure that nobody can take
  94  * the lock and put it on another transaction. */
  95 static inline int ocfs2_inode_fully_checkpointed(struct inode *inode)
  96 {
  97         int ret;
  98         struct ocfs2_journal *journal = OCFS2_SB(inode->i_sb)->journal;
  99
 100         spin_lock(&trans_inc_lock);
 101         ret = time_after(journal->j_trans_id, OCFS2_I(inode)->ip_last_trans);
 102         spin_unlock(&trans_inc_lock);
 103         return ret;
 104 }
 105
 106 /* convenience function to check if an inode is still new (has never
 107  * hit disk) Will do you a favor and set created_trans = 0 when you've
 108  * been checkpointed.  returns '1' if the inode is still new. */
 109 static inline int ocfs2_inode_is_new(struct inode *inode)
 110 {
 111         int ret;
 112
 113         /* System files are never "new" as they're written out by
 114          * mkfs. This helps us early during mount, before we have the
 115          * journal open and j_trans_id could be junk. */
 116         if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
 117                 return 0;
 118         spin_lock(&trans_inc_lock);
 119         ret = !(time_after(OCFS2_SB(inode->i_sb)->journal->j_trans_id,
 120                            OCFS2_I(inode)->ip_created_trans));
 121         if (!ret)
 122                 OCFS2_I(inode)->ip_created_trans = 0;
 123         spin_unlock(&trans_inc_lock);
 124         return ret;
 125 }
 126
 127 static inline void ocfs2_inode_set_new(struct ocfs2_super *osb,
 128                                        struct inode *inode)
 129 {
 130         spin_lock(&trans_inc_lock);
 131         OCFS2_I(inode)->ip_created_trans = osb->journal->j_trans_id;
 132         spin_unlock(&trans_inc_lock);
 133 }
 134
 135 /* Exported only for the journal struct init code in super.c. Do not call. */
 136 void ocfs2_complete_recovery(struct work_struct *work);
 137
 138 /*
 139  *  Journal Control:
 140  *  Initialize, Load, Shutdown, Wipe a journal.
 141  *
 142  *  ocfs2_journal_init     - Initialize journal structures in the OSB.
 143  *  ocfs2_journal_load     - Load the given journal off disk. Replay it if
 144  *                          there's transactions still in there.
 145  *  ocfs2_journal_shutdown - Shutdown a journal, this will flush all
 146  *                          uncommitted, uncheckpointed transactions.
 147  *  ocfs2_journal_wipe     - Wipe transactions from a journal. Optionally
 148  *                          zero out each block.
 149  *  ocfs2_recovery_thread  - Perform recovery on a node. osb is our own osb.
 150  *  ocfs2_mark_dead_nodes - Start recovery on nodes we won't get a heartbeat
 151  *                          event on.
 152  *  ocfs2_start_checkpoint - Kick the commit thread to do a checkpoint.
 153  */
 154 void   ocfs2_set_journal_params(struct ocfs2_super *osb);
 155 int    ocfs2_journal_init(struct ocfs2_journal *journal,
 156                           int *dirty);
 157 void   ocfs2_journal_shutdown(struct ocfs2_super *osb);
 158 int    ocfs2_journal_wipe(struct ocfs2_journal *journal,
 159                           int full);
 160 int    ocfs2_journal_load(struct ocfs2_journal *journal, int local);
 161 int    ocfs2_check_journals_nolocks(struct ocfs2_super *osb);
 162 void   ocfs2_recovery_thread(struct ocfs2_super *osb,
 163                              int node_num);
 164 int    ocfs2_mark_dead_nodes(struct ocfs2_super *osb);
 165 void   ocfs2_complete_mount_recovery(struct ocfs2_super *osb);
 166
 167 static inline void ocfs2_start_checkpoint(struct ocfs2_super *osb)
 168 {
 169         atomic_set(&osb->needs_checkpoint, 1);
 170         wake_up(&osb->checkpoint_event);
 171 }
 172
 173 static inline void ocfs2_checkpoint_inode(struct inode *inode)
 174 {
 175         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 176
 177         if (ocfs2_mount_local(osb))
 178                 return;
 179
 180         if (!ocfs2_inode_fully_checkpointed(inode)) {
 181                 /* WARNING: This only kicks off a single
 182                  * checkpoint. If someone races you and adds more
 183                  * metadata to the journal, you won't know, and will
 184                  * wind up waiting *alot* longer than necessary. Right
 185                  * now we only use this in clear_inode so that's
 186                  * OK. */
 187                 ocfs2_start_checkpoint(osb);
 188
 189                 wait_event(osb->journal->j_checkpointed,
 190                            ocfs2_inode_fully_checkpointed(inode));
 191         }
 192 }
 193
 194 /*
 195  *  Transaction Handling:
 196  *  Manage the lifetime of a transaction handle.
 197  *
 198  *  ocfs2_start_trans      - Begin a transaction. Give it an upper estimate of
 199  *                          the number of blocks that will be changed during
 200  *                          this handle.
 201  *  ocfs2_commit_trans - Complete a handle. It might return -EIO if
 202  *                       the journal was aborted. The majority of paths don't
 203  *                       check the return value as an error there comes too
 204  *                       late to do anything (and will be picked up in a
 205  *                       later transaction).
 206  *  ocfs2_extend_trans     - Extend a handle by nblocks credits. This may
 207  *                          commit the handle to disk in the process, but will
 208  *                          not release any locks taken during the transaction.
 209  *  ocfs2_journal_access   - Notify the handle that we want to journal this
 210  *                          buffer. Will have to call ocfs2_journal_dirty once
 211  *                          we've actually dirtied it. Type is one of . or .
 212  *  ocfs2_journal_dirty    - Mark a journalled buffer as having dirty data.
 213  *  ocfs2_journal_dirty_data - Indicate that a data buffer should go out before
 214  *                             the current handle commits.
 215  */
 216
 217 /* You must always start_trans with a number of buffs > 0, but it's
 218  * perfectly legal to go through an entire transaction without having
 219  * dirtied any buffers. */
 220 handle_t                    *ocfs2_start_trans(struct ocfs2_super *osb,
 221                                                int max_buffs);
 222 int                          ocfs2_commit_trans(struct ocfs2_super *osb,
 223                                                 handle_t *handle);
 224 int                          ocfs2_extend_trans(handle_t *handle, int nblocks);
 225
 226 /*
 227  * Create access is for when we get a newly created buffer and we're
 228  * not gonna read it off disk, but rather fill it ourselves.  Right
 229  * now, we don't do anything special with this (it turns into a write
 230  * request), but this is a good placeholder in case we do...
 231  *
 232  * Write access is for when we read a block off disk and are going to
 233  * modify it. This way the journalling layer knows it may need to make
 234  * a copy of that block (if it's part of another, uncommitted
 235  * transaction) before we do so.
 236  */
 237 #define OCFS2_JOURNAL_ACCESS_CREATE 0
 238 #define OCFS2_JOURNAL_ACCESS_WRITE  1
 239 #define OCFS2_JOURNAL_ACCESS_UNDO   2
 240
 241 int                  ocfs2_journal_access(handle_t *handle,
 242                                           struct inode *inode,
 243                                           struct buffer_head *bh,
 244                                           int type);
 245 /*
 246  * A word about the journal_access/journal_dirty "dance". It is
 247  * entirely legal to journal_access a buffer more than once (as long
 248  * as the access type is the same -- I'm not sure what will happen if
 249  * access type is different but this should never happen anyway) It is
 250  * also legal to journal_dirty a buffer more than once. In fact, you
 251  * can even journal_access a buffer after you've done a
 252  * journal_access/journal_dirty pair. The only thing you cannot do
 253  * however, is journal_dirty a buffer which you haven't yet passed to
 254  * journal_access at least once.
 255  *
 256  * That said, 99% of the time this doesn't matter and this is what the
 257  * path looks like:
 258  *
 259  *      <read a bh>
 260  *      ocfs2_journal_access(handle, bh,        OCFS2_JOURNAL_ACCESS_WRITE);
 261  *      <modify the bh>
 262  *      ocfs2_journal_dirty(handle, bh);
 263  */
 264 int                  ocfs2_journal_dirty(handle_t *handle,
 265                                          struct buffer_head *bh);
 266 int                  ocfs2_journal_dirty_data(handle_t *handle,
 267                                               struct buffer_head *bh);
 268
 269 /*
 270  *  Credit Macros:
 271  *  Convenience macros to calculate number of credits needed.
 272  *
 273  *  For convenience sake, I have a set of macros here which calculate
 274  *  the *maximum* number of sectors which will be changed for various
 275  *  metadata updates.
 276  */
 277
 278 /* simple file updates like chmod, etc. */
 279 #define OCFS2_INODE_UPDATE_CREDITS 1
 280
 281 /* get one bit out of a suballocator: dinode + group descriptor +
 282  * prev. group desc. if we relink. */
 283 #define OCFS2_SUBALLOC_ALLOC (3)
 284
 285 /* dinode + group descriptor update. We don't relink on free yet. */
 286 #define OCFS2_SUBALLOC_FREE  (2)
 287
 288 #define OCFS2_TRUNCATE_LOG_UPDATE OCFS2_INODE_UPDATE_CREDITS
 289 #define OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC (OCFS2_SUBALLOC_FREE                 \
 290                                          + OCFS2_TRUNCATE_LOG_UPDATE)
 291
 292 #define OCFS2_REMOVE_EXTENT_CREDITS (OCFS2_TRUNCATE_LOG_UPDATE + OCFS2_INODE_UPDATE_CREDITS)
 293
 294 /* data block for new dir/symlink, 2 for bitmap updates (bitmap fe +
 295  * bitmap block for the new bit) */
 296 #define OCFS2_DIR_LINK_ADDITIONAL_CREDITS (1 + 2)
 297
 298 /* parent fe, parent block, new file entry, inode alloc fe, inode alloc
 299  * group descriptor + mkdir/symlink blocks */
 300 #define OCFS2_MKNOD_CREDITS (3 + OCFS2_SUBALLOC_ALLOC                         \
 301                             + OCFS2_DIR_LINK_ADDITIONAL_CREDITS)
 302
 303 /* local alloc metadata change + main bitmap updates */
 304 #define OCFS2_WINDOW_MOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS                 \
 305                                   + OCFS2_SUBALLOC_ALLOC + OCFS2_SUBALLOC_FREE)
 306
 307 /* used when we don't need an allocation change for a dir extend. One
 308  * for the dinode, one for the new block. */
 309 #define OCFS2_SIMPLE_DIR_EXTEND_CREDITS (2)
 310
 311 /* file update (nlink, etc) + directory mtime/ctime + dir entry block */
 312 #define OCFS2_LINK_CREDITS  (2*OCFS2_INODE_UPDATE_CREDITS + 1)
 313
 314 /* inode + dir inode (if we unlink a dir), + dir entry block + orphan
 315  * dir inode link */
 316 #define OCFS2_UNLINK_CREDITS  (2 * OCFS2_INODE_UPDATE_CREDITS + 1             \
 317                               + OCFS2_LINK_CREDITS)
 318
 319 /* dinode + orphan dir dinode + inode alloc dinode + orphan dir entry +
 320  * inode alloc group descriptor */
 321 #define OCFS2_DELETE_INODE_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 1 + 1)
 322
 323 /* dinode update, old dir dinode update, new dir dinode update, old
 324  * dir dir entry, new dir dir entry, dir entry update for renaming
 325  * directory + target unlink */
 326 #define OCFS2_RENAME_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 3              \
 327                              + OCFS2_UNLINK_CREDITS)
 328
 329 static inline int ocfs2_calc_extend_credits(struct super_block *sb,
 330                                             struct ocfs2_dinode *fe,
 331                                             u32 bits_wanted)
 332 {
 333         int bitmap_blocks, sysfile_bitmap_blocks, dinode_blocks;
 334
 335         /* bitmap dinode, group desc. + relinked group. */
 336         bitmap_blocks = OCFS2_SUBALLOC_ALLOC;
 337
 338         /* we might need to shift tree depth so lets assume an
 339          * absolute worst case of complete fragmentation.  Even with
 340          * that, we only need one update for the dinode, and then
 341          * however many metadata chunks needed * a remaining suballoc
 342          * alloc. */
 343         sysfile_bitmap_blocks = 1 +
 344                 (OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(fe);
 345
 346         /* this does not include *new* metadata blocks, which are
 347          * accounted for in sysfile_bitmap_blocks. fe +
 348          * prev. last_eb_blk + blocks along edge of tree.
 349          * calc_symlink_credits passes because we just need 1
 350          * credit for the dinode there. */
 351         dinode_blocks = 1 + 1 + le16_to_cpu(fe->id2.i_list.l_tree_depth);
 352
 353         return bitmap_blocks + sysfile_bitmap_blocks + dinode_blocks;
 354 }
 355
 356 static inline int ocfs2_calc_symlink_credits(struct super_block *sb)
 357 {
 358         int blocks = OCFS2_MKNOD_CREDITS;
 359
 360         /* links can be longer than one block so we may update many
 361          * within our single allocated extent. */
 362         blocks += ocfs2_clusters_to_blocks(sb, 1);
 363
 364         return blocks;
 365 }
 366
 367 static inline int ocfs2_calc_group_alloc_credits(struct super_block *sb,
 368                                                  unsigned int cpg)
 369 {
 370         int blocks;
 371         int bitmap_blocks = OCFS2_SUBALLOC_ALLOC + 1;
 372         /* parent inode update + new block group header + bitmap inode update
 373            + bitmap blocks affected */
 374         blocks = 1 + 1 + 1 + bitmap_blocks;
 375         return blocks;
 376 }
 377
 378 static inline int ocfs2_calc_tree_trunc_credits(struct super_block *sb,
 379                                                 unsigned int clusters_to_del,
 380                                                 struct ocfs2_dinode *fe,
 381                                                 struct ocfs2_extent_list *last_el)
 382 {
 383         /* for dinode + all headers in this pass + update to next leaf */
 384         u16 next_free = le16_to_cpu(last_el->l_next_free_rec);
 385         u16 tree_depth = le16_to_cpu(fe->id2.i_list.l_tree_depth);
 386         int credits = 1 + tree_depth + 1;
 387         int i;
 388
 389         i = next_free - 1;
 390         BUG_ON(i < 0);
 391
 392         /* We may be deleting metadata blocks, so metadata alloc dinode +
 393            one desc. block for each possible delete. */
 394         if (tree_depth && next_free == 1 &&
 395             ocfs2_rec_clusters(last_el, &last_el->l_recs[i]) == clusters_to_del)
 396                 credits += 1 + tree_depth;
 397
 398         /* update to the truncate log. */
 399         credits += OCFS2_TRUNCATE_LOG_UPDATE;
 400
 401         return credits;
 402 }
 403
 404 #endif /* OCFS2_JOURNAL_H */