/* searches in journal structures for a given block number (bmap, off). If block
is found in reiserfs journal it suggests next free block candidate to test. */
static inline int is_block_in_journal (struct super_block * s, int bmap, int off, int *next)
{
unsigned int tmp;
if (reiserfs_in_journal (s, s->s_dev, bmap, off, s->s_blocksize, 1, &tmp)) {
if (tmp) { /* hint supplied */
*next = tmp;
PROC_INFO_INC( s, scan_bitmap.in_journal_hint );
} else {
(*next) = off + 1; /* inc offset to avoid looping. */
PROC_INFO_INC( s, scan_bitmap.in_journal_nohint );
}
PROC_INFO_INC( s, scan_bitmap.retry );
return 1;
}
return 0;
}
/* The function is NOT SCHEDULE-SAFE! */
static int find_forward (struct super_block * s, int * bmap_nr, int * offset, int for_unformatted)
{
int i, j;
struct buffer_head * bh;
unsigned long block_to_try = 0;
unsigned long next_block_to_try = 0 ;
PROC_INFO_INC( s, find_forward.call );
for (i = *bmap_nr; i < SB_BMAP_NR (s); i ++, *offset = 0,
PROC_INFO_INC( s, find_forward.bmap )) {
/* get corresponding bitmap block */
bh = SB_AP_BITMAP (s)[i];
if (buffer_locked (bh)) {
PROC_INFO_INC( s, find_forward.wait );
__wait_on_buffer (bh);
}
retry:
j = reiserfs_find_next_zero_le_bit ((unsigned long *)bh->b_data,
s->s_blocksize << 3, *offset);
/* wow, this really needs to be redone. We can't allocate a block if
** it is in the journal somehow. reiserfs_in_journal makes a suggestion
** for a good block if the one you ask for is in the journal. Note,
** reiserfs_in_journal might reject the block it suggests. The big
** gain from the suggestion is when a big file has been deleted, and
** many blocks show free in the real bitmap, but are all not free
** in the journal list bitmaps.
**
** this whole system sucks. The bitmaps should reflect exactly what
** can and can't be allocated, and the journal should update them as
** it goes. TODO.
*/
if (j < (s->s_blocksize << 3)) {
block_to_try = (i * (s->s_blocksize << 3)) + j;
/* the block is not in the journal, we can proceed */
if (!(reiserfs_in_journal(s, s->s_dev, block_to_try, s->s_blocksize, for_unformatted, &next_block_to_try))) {
*bmap_nr = i;
*offset = j;
return 1;
}
/* the block is in the journal */
else if ((j+1) < (s->s_blocksize << 3)) { /* try again */
/* reiserfs_in_journal suggested a new block to try */
if (next_block_to_try > 0) {
int new_i ;
get_bit_address (s, next_block_to_try, &new_i, offset);
PROC_INFO_INC( s, find_forward.in_journal_hint );
/* block is not in this bitmap. reset i and continue
** we only reset i if new_i is in a later bitmap.
*/
if (new_i > i) {
i = (new_i - 1 ); /* i gets incremented by the for loop */
PROC_INFO_INC( s, find_forward.in_journal_out );
continue ;
}
} else {
/* no suggestion was made, just try the next block */
*offset = j+1 ;
}
PROC_INFO_INC( s, find_forward.retry );
goto retry ;
}
}
}
/* zero bit not found */
return 0;
}
