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 void ocfs2_wait_for_recovery(struct ocfs2_super *osb);
 138
 139 int ocfs2_recovery_init(struct ocfs2_super *osb);
 140 void ocfs2_recovery_exit(struct ocfs2_super *osb);
 141
 142 /*
 143  *  Journal Control:
 144  *  Initialize, Load, Shutdown, Wipe a journal.
 145  *
 146  *  ocfs2_journal_init     - Initialize journal structures in the OSB.
 147  *  ocfs2_journal_load     - Load the given journal off disk. Replay it if
 148  *                          there's transactions still in there.
 149  *  ocfs2_journal_shutdown - Shutdown a journal, this will flush all
 150  *                          uncommitted, uncheckpointed transactions.
 151  *  ocfs2_journal_wipe     - Wipe transactions from a journal. Optionally
 152  *                          zero out each block.
 153  *  ocfs2_recovery_thread  - Perform recovery on a node. osb is our own osb.
 154  *  ocfs2_mark_dead_nodes - Start recovery on nodes we won't get a heartbeat
 155  *                          event on.
 156  *  ocfs2_start_checkpoint - Kick the commit thread to do a checkpoint.
 157  */
 158 void   ocfs2_set_journal_params(struct ocfs2_super *osb);
 159 int    ocfs2_journal_init(struct ocfs2_journal *journal,
 160                           int *dirty);
 161 void   ocfs2_journal_shutdown(struct ocfs2_super *osb);
 162 int    ocfs2_journal_wipe(struct ocfs2_journal *journal,
 163                           int full);
 164 int    ocfs2_journal_load(struct ocfs2_journal *journal, int local);
 165 int    ocfs2_check_journals_nolocks(struct ocfs2_super *osb);
 166 void   ocfs2_recovery_thread(struct ocfs2_super *osb,
 167                              int node_num);
 168 int    ocfs2_mark_dead_nodes(struct ocfs2_super *osb);
 169 void   ocfs2_complete_mount_recovery(struct ocfs2_super *osb);
 170
 171 static inline void ocfs2_start_checkpoint(struct ocfs2_super *osb)
 172 {
 173         atomic_set(&osb->needs_checkpoint, 1);
 174         wake_up(&osb->checkpoint_event);
 175 }
 176
 177 static inline void ocfs2_checkpoint_inode(struct inode *inode)
 178 {
 179         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 180
 181         if (ocfs2_mount_local(osb))
 182                 return;
 183
 184         if (!ocfs2_inode_fully_checkpointed(inode)) {
 185                 /* WARNING: This only kicks off a single
 186                  * checkpoint. If someone races you and adds more
 187                  * metadata to the journal, you won't know, and will
 188                  * wind up waiting *alot* longer than necessary. Right
 189                  * now we only use this in clear_inode so that's
 190                  * OK. */
 191                 ocfs2_start_checkpoint(osb);
 192
 193                 wait_event(osb->journal->j_checkpointed,
 194                            ocfs2_inode_fully_checkpointed(inode));
 195         }
 196 }
 197
 198 /*
 199  *  Transaction Handling:
 200  *  Manage the lifetime of a transaction handle.
 201  *
 202  *  ocfs2_start_trans      - Begin a transaction. Give it an upper estimate of
 203  *                          the number of blocks that will be changed during
 204  *                          this handle.
 205  *  ocfs2_commit_trans - Complete a handle. It might return -EIO if
 206  *                       the journal was aborted. The majority of paths don't
 207  *                       check the return value as an error there comes too
 208  *                       late to do anything (and will be picked up in a
 209  *                       later transaction).
 210  *  ocfs2_extend_trans     - Extend a handle by nblocks credits. This may
 211  *                          commit the handle to disk in the process, but will
 212  *                          not release any locks taken during the transaction.
 213  *  ocfs2_journal_access   - Notify the handle that we want to journal this
 214  *                          buffer. Will have to call ocfs2_journal_dirty once
 215  *                          we've actually dirtied it. Type is one of . or .
 216  *  ocfs2_journal_dirty    - Mark a journalled buffer as having dirty data.
 217  *  ocfs2_journal_dirty_data - Indicate that a data buffer should go out before
 218  *                             the current handle commits.
 219  */
 220
 221 /* You must always start_trans with a number of buffs > 0, but it's
 222  * perfectly legal to go through an entire transaction without having
 223  * dirtied any buffers. */
 224 handle_t                    *ocfs2_start_trans(struct ocfs2_super *osb,
 225                                                int max_buffs);
 226 int                          ocfs2_commit_trans(struct ocfs2_super *osb,
 227                                                 handle_t *handle);
 228 int                          ocfs2_extend_trans(handle_t *handle, int nblocks);
 229
 230 /*
 231  * Create access is for when we get a newly created buffer and we're
 232  * not gonna read it off disk, but rather fill it ourselves.  Right
 233  * now, we don't do anything special with this (it turns into a write
 234  * request), but this is a good placeholder in case we do...
 235  *
 236  * Write access is for when we read a block off disk and are going to
 237  * modify it. This way the journalling layer knows it may need to make
 238  * a copy of that block (if it's part of another, uncommitted
 239  * transaction) before we do so.
 240  */
 241 #define OCFS2_JOURNAL_ACCESS_CREATE 0
 242 #define OCFS2_JOURNAL_ACCESS_WRITE  1
 243 #define OCFS2_JOURNAL_ACCESS_UNDO   2
 244
 245 int                  ocfs2_journal_access(handle_t *handle,
 246                                           struct inode *inode,
 247                                           struct buffer_head *bh,
 248                                           int type);
 249 /*
 250  * A word about the journal_access/journal_dirty "dance". It is
 251  * entirely legal to journal_access a buffer more than once (as long
 252  * as the access type is the same -- I'm not sure what will happen if
 253  * access type is different but this should never happen anyway) It is
 254  * also legal to journal_dirty a buffer more than once. In fact, you
 255  * can even journal_access a buffer after you've done a
 256  * journal_access/journal_dirty pair. The only thing you cannot do
 257  * however, is journal_dirty a buffer which you haven't yet passed to
 258  * journal_access at least once.
 259  *
 260  * That said, 99% of the time this doesn't matter and this is what the
 261  * path looks like:
 262  *
 263  *      <read a bh>
 264  *      ocfs2_journal_access(handle, bh,        OCFS2_JOURNAL_ACCESS_WRITE);
 265  *      <modify the bh>
 266  *      ocfs2_journal_dirty(handle, bh);
 267  */
 268 int                  ocfs2_journal_dirty(handle_t *handle,
 269                                          struct buffer_head *bh);
 270 int                  ocfs2_journal_dirty_data(handle_t *handle,
 271                                               struct buffer_head *bh);
 272
 273 /*
 274  *  Credit Macros:
 275  *  Convenience macros to calculate number of credits needed.
 276  *
 277  *  For convenience sake, I have a set of macros here which calculate
 278  *  the *maximum* number of sectors which will be changed for various
 279  *  metadata updates.
 280  */
 281
 282 /* simple file updates like chmod, etc. */
 283 #define OCFS2_INODE_UPDATE_CREDITS 1
 284
 285 /* group extend. inode update and last group update. */
 286 #define OCFS2_GROUP_EXTEND_CREDITS      (OCFS2_INODE_UPDATE_CREDITS + 1)
 287
 288 /* group add. inode update and the new group update. */
 289 #define OCFS2_GROUP_ADD_CREDITS (OCFS2_INODE_UPDATE_CREDITS + 1)
 290
 291 /* get one bit out of a suballocator: dinode + group descriptor +
 292  * prev. group desc. if we relink. */
 293 #define OCFS2_SUBALLOC_ALLOC (3)
 294
 295 #define OCFS2_INLINE_TO_EXTENTS_CREDITS (OCFS2_SUBALLOC_ALLOC           \
 296                                          + OCFS2_INODE_UPDATE_CREDITS)
 297
 298 /* dinode + group descriptor update. We don't relink on free yet. */
 299 #define OCFS2_SUBALLOC_FREE  (2)
 300
 301 #define OCFS2_TRUNCATE_LOG_UPDATE OCFS2_INODE_UPDATE_CREDITS
 302 #define OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC (OCFS2_SUBALLOC_FREE                 \
 303                                          + OCFS2_TRUNCATE_LOG_UPDATE)
 304
 305 #define OCFS2_REMOVE_EXTENT_CREDITS (OCFS2_TRUNCATE_LOG_UPDATE + OCFS2_INODE_UPDATE_CREDITS)
 306
 307 /* data block for new dir/symlink, 2 for bitmap updates (bitmap fe +
 308  * bitmap block for the new bit) */
 309 #define OCFS2_DIR_LINK_ADDITIONAL_CREDITS (1 + 2)
 310
 311 /* parent fe, parent block, new file entry, inode alloc fe, inode alloc
 312  * group descriptor + mkdir/symlink blocks */
 313 #define OCFS2_MKNOD_CREDITS (3 + OCFS2_SUBALLOC_ALLOC                         \
 314                             + OCFS2_DIR_LINK_ADDITIONAL_CREDITS)
 315
 316 /* local alloc metadata change + main bitmap updates */
 317 #define OCFS2_WINDOW_MOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS                 \
 318                                   + OCFS2_SUBALLOC_ALLOC + OCFS2_SUBALLOC_FREE)
 319
 320 /* used when we don't need an allocation change for a dir extend. One
 321  * for the dinode, one for the new block. */
 322 #define OCFS2_SIMPLE_DIR_EXTEND_CREDITS (2)
 323
 324 /* file update (nlink, etc) + directory mtime/ctime + dir entry block */
 325 #define OCFS2_LINK_CREDITS  (2*OCFS2_INODE_UPDATE_CREDITS + 1)
 326
 327 /* inode + dir inode (if we unlink a dir), + dir entry block + orphan
 328  * dir inode link */
 329 #define OCFS2_UNLINK_CREDITS  (2 * OCFS2_INODE_UPDATE_CREDITS + 1             \
 330                               + OCFS2_LINK_CREDITS)
 331
 332 /* dinode + orphan dir dinode + inode alloc dinode + orphan dir entry +
 333  * inode alloc group descriptor */
 334 #define OCFS2_DELETE_INODE_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 1 + 1)
 335
 336 /* dinode update, old dir dinode update, new dir dinode update, old
 337  * dir dir entry, new dir dir entry, dir entry update for renaming
 338  * directory + target unlink */
 339 #define OCFS2_RENAME_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 3              \
 340                              + OCFS2_UNLINK_CREDITS)
 341
 342 static inline int ocfs2_calc_extend_credits(struct super_block *sb,
 343                                             struct ocfs2_dinode *fe,
 344                                             u32 bits_wanted)
 345 {
 346         int bitmap_blocks, sysfile_bitmap_blocks, dinode_blocks;
 347
 348         /* bitmap dinode, group desc. + relinked group. */
 349         bitmap_blocks = OCFS2_SUBALLOC_ALLOC;
 350
 351         /* we might need to shift tree depth so lets assume an
 352          * absolute worst case of complete fragmentation.  Even with
 353          * that, we only need one update for the dinode, and then
 354          * however many metadata chunks needed * a remaining suballoc
 355          * alloc. */
 356         sysfile_bitmap_blocks = 1 +
 357                 (OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(fe);
 358
 359         /* this does not include *new* metadata blocks, which are
 360          * accounted for in sysfile_bitmap_blocks. fe +
 361          * prev. last_eb_blk + blocks along edge of tree.
 362          * calc_symlink_credits passes because we just need 1
 363          * credit for the dinode there. */
 364         dinode_blocks = 1 + 1 + le16_to_cpu(fe->id2.i_list.l_tree_depth);
 365
 366         return bitmap_blocks + sysfile_bitmap_blocks + dinode_blocks;
 367 }
 368
 369 static inline int ocfs2_calc_symlink_credits(struct super_block *sb)
 370 {
 371         int blocks = OCFS2_MKNOD_CREDITS;
 372
 373         /* links can be longer than one block so we may update many
 374          * within our single allocated extent. */
 375         blocks += ocfs2_clusters_to_blocks(sb, 1);
 376
 377         return blocks;
 378 }
 379
 380 static inline int ocfs2_calc_group_alloc_credits(struct super_block *sb,
 381                                                  unsigned int cpg)
 382 {
 383         int blocks;
 384         int bitmap_blocks = OCFS2_SUBALLOC_ALLOC + 1;
 385         /* parent inode update + new block group header + bitmap inode update
 386            + bitmap blocks affected */
 387         blocks = 1 + 1 + 1 + bitmap_blocks;
 388         return blocks;
 389 }
 390
 391 static inline int ocfs2_calc_tree_trunc_credits(struct super_block *sb,
 392                                                 unsigned int clusters_to_del,
 393                                                 struct ocfs2_dinode *fe,
 394                                                 struct ocfs2_extent_list *last_el)
 395 {
 396         /* for dinode + all headers in this pass + update to next leaf */
 397         u16 next_free = le16_to_cpu(last_el->l_next_free_rec);
 398         u16 tree_depth = le16_to_cpu(fe->id2.i_list.l_tree_depth);
 399         int credits = 1 + tree_depth + 1;
 400         int i;
 401
 402         i = next_free - 1;
 403         BUG_ON(i < 0);
 404
 405         /* We may be deleting metadata blocks, so metadata alloc dinode +
 406            one desc. block for each possible delete. */
 407         if (tree_depth && next_free == 1 &&
 408             ocfs2_rec_clusters(last_el, &last_el->l_recs[i]) == clusters_to_del)
 409                 credits += 1 + tree_depth;
 410
 411         /* update to the truncate log. */
 412         credits += OCFS2_TRUNCATE_LOG_UPDATE;
 413
 414         return credits;
 415 }
 416
 417 #endif /* OCFS2_JOURNAL_H */