journal.c

Linux Kernel 2.6.9 for OMAP1710

  if (bh) 
    return test_bit(BH_JNew, &bh->b_state) ;
  else
    return 0 ;
}

inline int mark_buffer_journal_new(struct buffer_head *bh) {
  if (bh) {
    set_bit(BH_JNew, &bh->b_state) ;
  }
  return 0 ;
}

inline int mark_buffer_not_journaled(struct buffer_head *bh) {
  if (bh) 
    clear_bit(BH_JDirty, &bh->b_state) ;
  return 0 ;
}

/* utility function to force a BUG if it is called without the big
** kernel lock held.  caller is the string printed just before calling BUG()
*/
void reiserfs_check_lock_depth(struct super_block *sb, char *caller) {
#ifdef CONFIG_SMP
  if (current->lock_depth < 0) {
    reiserfs_panic (sb, "%s called without kernel lock held", caller) ;
  }
#else
  ;
#endif
}

/* return a cnode with same dev, block number and size in table, or null if not found */
static inline struct reiserfs_journal_cnode *
get_journal_hash_dev(struct super_block *sb,
		     struct reiserfs_journal_cnode **table,
		     long bl)
{
  struct reiserfs_journal_cnode *cn ;
  cn = journal_hash(table, sb, bl) ;
  while(cn) {
    if (cn->blocknr == bl && cn->sb == sb)
      return cn ;
    cn = cn->hnext ;
  }
  return (struct reiserfs_journal_cnode *)0 ;
}

/* returns a cnode with same size, block number and dev as bh in the current transaction hash.  NULL if not found */
static inline struct reiserfs_journal_cnode *get_journal_hash(struct super_block *p_s_sb, struct buffer_head *bh) {
  struct reiserfs_journal_cnode *cn ;
  if (bh) {
    cn =  get_journal_hash_dev(p_s_sb, SB_JOURNAL(p_s_sb)->j_hash_table, bh->b_blocknr);
  }
  else {
    return (struct reiserfs_journal_cnode *)0 ;
  }
  return cn ;
}

/*
** this actually means 'can this block be reallocated yet?'.  If you set search_all, a block can only be allocated
** if it is not in the current transaction, was not freed by the current transaction, and has no chance of ever
** being overwritten by a replay after crashing.
**
** If you don't set search_all, a block can only be allocated if it is not in the current transaction.  Since deleting
** a block removes it from the current transaction, this case should never happen.  If you don't set search_all, make
** sure you never write the block without logging it.
**
** next_zero_bit is a suggestion about the next block to try for find_forward.
** when bl is rejected because it is set in a journal list bitmap, we search
** for the next zero bit in the bitmap that rejected bl.  Then, we return that
** through next_zero_bit for find_forward to try.
**
** Just because we return something in next_zero_bit does not mean we won't
** reject it on the next call to reiserfs_in_journal
**
*/
int reiserfs_in_journal(struct super_block *p_s_sb,
                        int bmap_nr, int bit_nr, int search_all, 
			b_blocknr_t *next_zero_bit) {
  struct reiserfs_journal_cnode *cn ;
  struct reiserfs_list_bitmap *jb ;
  int i ;
  unsigned long bl;

  *next_zero_bit = 0 ; /* always start this at zero. */

  PROC_INFO_INC( p_s_sb, journal.in_journal );
  /* If we aren't doing a search_all, this is a metablock, and it will be logged before use.
  ** if we crash before the transaction that freed it commits,  this transaction won't
  ** have committed either, and the block will never be written
  */
  if (search_all) {
    for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
      PROC_INFO_INC( p_s_sb, journal.in_journal_bitmap );
      jb = SB_JOURNAL(p_s_sb)->j_list_bitmap + i ;
      if (jb->journal_list && jb->bitmaps[bmap_nr] &&
          test_bit(bit_nr, (unsigned long *)jb->bitmaps[bmap_nr]->data)) {
	*next_zero_bit = find_next_zero_bit((unsigned long *)
	                             (jb->bitmaps[bmap_nr]->data),
	                             p_s_sb->s_blocksize << 3, bit_nr+1) ; 
	return 1 ;
      }
    }
  }

  bl = bmap_nr * (p_s_sb->s_blocksize << 3) + bit_nr;
  /* is it in any old transactions? */
  if (search_all && (cn = get_journal_hash_dev(p_s_sb, SB_JOURNAL(p_s_sb)->j_list_hash_table, bl))) {
    return 1; 
  }

  /* is it in the current transaction.  This should never happen */
  if ((cn = get_journal_hash_dev(p_s_sb, SB_JOURNAL(p_s_sb)->j_hash_table, bl))) {
    BUG();
    return 1; 
  }

  PROC_INFO_INC( p_s_sb, journal.in_journal_reusable );
  /* safe for reuse */
  return 0 ;
}

/* insert cn into table
*/
inline void insert_journal_hash(struct reiserfs_journal_cnode **table, struct reiserfs_journal_cnode *cn) {
  struct reiserfs_journal_cnode *cn_orig ;

  cn_orig = journal_hash(table, cn->sb, cn->blocknr) ;
  cn->hnext = cn_orig ;
  cn->hprev = NULL ;
  if (cn_orig) {
    cn_orig->hprev = cn ;
  }
  journal_hash(table, cn->sb, cn->blocknr) =  cn ;
}

/* lock the current transaction */
inline static void lock_journal(struct super_block *p_s_sb) {
    PROC_INFO_INC( p_s_sb, journal.lock_journal );
    down(&SB_JOURNAL(p_s_sb)->j_lock);
}

/* unlock the current transaction */
inline static void unlock_journal(struct super_block *p_s_sb) {
    up(&SB_JOURNAL(p_s_sb)->j_lock);
}

static inline void get_journal_list(struct reiserfs_journal_list *jl)
{
    jl->j_refcount++;
}

static inline void put_journal_list(struct super_block *s,
                                   struct reiserfs_journal_list *jl)
{
    if (jl->j_refcount < 1) {
        reiserfs_panic (s, "trans id %lu, refcount at %d", jl->j_trans_id,
	                                         jl->j_refcount);
    }
    if (--jl->j_refcount == 0)
        reiserfs_kfree(jl, sizeof(struct reiserfs_journal_list), s);
}

/*
** this used to be much more involved, and I'm keeping it just in case things get ugly again.
** it gets called by flush_commit_list, and cleans up any data stored about blocks freed during a
** transaction.
*/
static void cleanup_freed_for_journal_list(struct super_block *p_s_sb, struct reiserfs_journal_list *jl) {

  struct reiserfs_list_bitmap *jb = jl->j_list_bitmap ;
  if (jb) {
    cleanup_bitmap_list(p_s_sb, jb) ;
  }
  jl->j_list_bitmap->journal_list = NULL ;
  jl->j_list_bitmap = NULL ;
}

static int journal_list_still_alive(struct super_block *s,
                                    unsigned long trans_id)
{
    struct list_head *entry = &SB_JOURNAL(s)->j_journal_list;
    struct reiserfs_journal_list *jl;

    if (!list_empty(entry)) {
        jl = JOURNAL_LIST_ENTRY(entry->next);
	if (jl->j_trans_id <= trans_id) {
	    return 1;
	}
    }
    return 0;
}

static void reiserfs_end_buffer_io_sync(struct buffer_head *bh, int uptodate) {
    char b[BDEVNAME_SIZE];

    if (buffer_journaled(bh)) {
        reiserfs_warning(NULL, "clm-2084: pinned buffer %lu:%s sent to disk",
	                 bh->b_blocknr, bdevname(bh->b_bdev, b)) ;
    }
    if (uptodate)
    	set_buffer_uptodate(bh) ;
    else
    	clear_buffer_uptodate(bh) ;
    unlock_buffer(bh) ;
    put_bh(bh) ;
}

static void reiserfs_end_ordered_io(struct buffer_head *bh, int uptodate) {
    if (uptodate)
    	set_buffer_uptodate(bh) ;
    else
    	clear_buffer_uptodate(bh) ;
    unlock_buffer(bh) ;
    put_bh(bh) ;
}

static void submit_logged_buffer(struct buffer_head *bh) {
    get_bh(bh) ;
    bh->b_end_io = reiserfs_end_buffer_io_sync ;
    mark_buffer_notjournal_new(bh) ;
    clear_buffer_dirty(bh) ;
    if (!test_and_clear_bit(BH_JTest, &bh->b_state))
        BUG();
    if (!buffer_uptodate(bh))
        BUG();
    submit_bh(WRITE, bh) ;
}

static void submit_ordered_buffer(struct buffer_head *bh) {
    get_bh(bh) ;
    bh->b_end_io = reiserfs_end_ordered_io;
    clear_buffer_dirty(bh) ;
    if (!buffer_uptodate(bh))
        BUG();
    submit_bh(WRITE, bh) ;
}

static int submit_barrier_buffer(struct buffer_head *bh) {
    get_bh(bh) ;
    bh->b_end_io = reiserfs_end_ordered_io;
    clear_buffer_dirty(bh) ;
    if (!buffer_uptodate(bh))
        BUG();
    return submit_bh(WRITE_BARRIER, bh) ;
}

static void check_barrier_completion(struct super_block *s,
                                     struct buffer_head *bh) {
    if (buffer_eopnotsupp(bh)) {
	clear_buffer_eopnotsupp(bh);
	disable_barrier(s);
	set_buffer_uptodate(bh);
	set_buffer_dirty(bh);
	sync_dirty_buffer(bh);
    }
}

#define CHUNK_SIZE 32
struct buffer_chunk {
    struct buffer_head *bh[CHUNK_SIZE];
    int nr;
};

static void write_chunk(struct buffer_chunk *chunk) {
    int i;
    for (i = 0; i < chunk->nr ; i++) {
	submit_logged_buffer(chunk->bh[i]) ;
    }
    chunk->nr = 0;
}

static void write_ordered_chunk(struct buffer_chunk *chunk) {
    int i;
    for (i = 0; i < chunk->nr ; i++) {
	submit_ordered_buffer(chunk->bh[i]) ;
    }
    chunk->nr = 0;
}

static int add_to_chunk(struct buffer_chunk *chunk, struct buffer_head *bh,
			 spinlock_t *lock,
			 void (fn)(struct buffer_chunk *))
{
    int ret = 0;
    if (chunk->nr >= CHUNK_SIZE)
        BUG();
    chunk->bh[chunk->nr++] = bh;
    if (chunk->nr >= CHUNK_SIZE) {
	ret = 1;
        if (lock)
	    spin_unlock(lock);
        fn(chunk);
        if (lock)
	    spin_lock(lock);
    }
    return ret;
}


atomic_t nr_reiserfs_jh = ATOMIC_INIT(0);
static struct reiserfs_jh *alloc_jh(void) {
    struct reiserfs_jh *jh;
    while(1) {
	jh = kmalloc(sizeof(*jh), GFP_NOFS);
	if (jh) {
	    atomic_inc(&nr_reiserfs_jh);
	    return jh;
	}
        yield();
    }
}

/*
 * we want to free the jh when the buffer has been written
 * and waited on
 */
void reiserfs_free_jh(struct buffer_head *bh) {
    struct reiserfs_jh *jh;

    jh = bh->b_private;
    if (jh) {
	bh->b_private = NULL;
	jh->bh = NULL;
	list_del_init(&jh->list);
	kfree(jh);
	if (atomic_read(&nr_reiserfs_jh) <= 0)
	    BUG();
	atomic_dec(&nr_reiserfs_jh);
	put_bh(bh);
    }
}

static inline int __add_jh(struct reiserfs_journal *j, struct buffer_head *bh,
                           int tail)
{
    struct reiserfs_jh *jh;

    if (bh->b_private) {
	spin_lock(&j->j_dirty_buffers_lock);
	if (!bh->b_private) {
	    spin_unlock(&j->j_dirty_buffers_lock);
	    goto no_jh;
	}
        jh = bh->b_private;
	list_del_init(&jh->list);
    } else {
no_jh:
	get_bh(bh);
	jh = alloc_jh();
	spin_lock(&j->j_dirty_buffers_lock);
	/* buffer must be locked for __add_jh, should be able to have
	 * two adds at the same time
	 */
	if (bh->b_private)
	    BUG();
	jh->bh = bh;
	bh->b_private = jh;
    }
    jh->jl = j->j_current_jl;
    if (tail)
	list_add_tail(&jh->list, &jh->jl->j_tail_bh_list);
    else {
	list_add_tail(&jh->list, &jh->jl->j_bh_list);
    }
    spin_unlock(&j->j_dirty_buffers_lock);
    return 0;
}

int reiserfs_add_tail_list(struct inode *inode, struct buffer_head *bh) {
    return __add_jh(SB_JOURNAL(inode->i_sb), bh, 1);
}
int reiserfs_add_ordered_list(struct inode *inode, struct buffer_head *bh) {
    return __add_jh(SB_JOURNAL(inode->i_sb), bh, 0);
}

#define JH_ENTRY(l) list_entry((l), struct reiserfs_jh, list)
static int write_ordered_buffers(spinlock_t *lock,
				 struct reiserfs_journal *j,
                                 struct reiserfs_journal_list *jl,
				 struct list_head *list)
{
    struct buffer_head *bh;
    struct reiserfs_jh *jh;
    int ret = 0;
    struct buffer_chunk chunk;
    struct list_head tmp;
    INIT_LIST_HEAD(&tmp);

    chunk.nr = 0;
    spin_lock(lock);
    while(!list_empty(list)) {
        jh = JH_ENTRY(list->next);
	bh = jh->bh;
	get_bh(bh);
	if (test_set_buffer_locked(bh)) {
	    if (!buffer_dirty(bh)) {
		list_del_init(&jh->list);
		list_add(&jh->list, &tmp);
		goto loop_next;
	    }
	    spin_unlock(lock);
	    if (chunk.nr)
		write_ordered_chunk(&chunk);
	    wait_on_buffer(bh);
	    cond_resched();