[PATCH] reiserfs: clean up bitmap block buffer head references
Similar to the SB_JOURNAL cleanup that was accepted a while ago, this patch
uses a temporary variable for buffer head references from the bitmap info
array.
This makes the code much more readable in some areas.
It also uses proper reference counting, doing a get_bh() after using the
pointer from the array and brelse()'ing it later. This may seem silly, but a
later patch will replace the simple temporary variables with an actual read,
so the reference freeing will be used then.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index 1022347..44d9410 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -59,6 +59,7 @@
int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
{
int bmap, offset;
+ struct buffer_head *bh;
if (block == 0 || block >= SB_BLOCK_COUNT(s)) {
reiserfs_warning(s,
@@ -96,20 +97,21 @@
return 0;
}
- if ((bit_value == 0 &&
- reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data)) ||
- (bit_value == 1 &&
- reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data) == 0)) {
+ bh = SB_AP_BITMAP(s)[bmap].bh;
+ get_bh(bh);
+
+ if ((bit_value == 0 && reiserfs_test_le_bit(offset, bh->b_data)) ||
+ (bit_value == 1 && reiserfs_test_le_bit(offset, bh->b_data) == 0)) {
reiserfs_warning(s,
"vs-4040: is_reusable: corresponding bit of block %lu does not "
"match required value (bmap==%d, offset==%d) test_bit==%d",
- block, bmap, offset, reiserfs_test_le_bit(offset,
- SB_AP_BITMAP
- (s)[bmap].bh->
- b_data));
+ block, bmap, offset,
+ reiserfs_test_le_bit(offset, bh->b_data));
+ brelse(bh);
return 0;
}
+ brelse(bh);
if (bit_value == 0 && block == SB_ROOT_BLOCK(s)) {
reiserfs_warning(s,
@@ -151,6 +153,7 @@
{
struct super_block *s = th->t_super;
struct reiserfs_bitmap_info *bi = &SB_AP_BITMAP(s)[bmap_n];
+ struct buffer_head *bh;
int end, next;
int org = *beg;
@@ -169,22 +172,28 @@
bmap_n);
return 0;
}
- if (buffer_locked(bi->bh)) {
+ bh = bi->bh;
+ get_bh(bh);
+
+ if (buffer_locked(bh)) {
PROC_INFO_INC(s, scan_bitmap.wait);
- __wait_on_buffer(bi->bh);
+ __wait_on_buffer(bh);
}
while (1) {
cont:
- if (bi->free_count < min)
+ if (bi->free_count < min) {
+ brelse(bh);
return 0; // No free blocks in this bitmap
+ }
/* search for a first zero bit -- beggining of a window */
*beg = reiserfs_find_next_zero_le_bit
- ((unsigned long *)(bi->bh->b_data), boundary, *beg);
+ ((unsigned long *)(bh->b_data), boundary, *beg);
if (*beg + min > boundary) { /* search for a zero bit fails or the rest of bitmap block
* cannot contain a zero window of minimum size */
+ brelse(bh);
return 0;
}
@@ -193,7 +202,7 @@
/* first zero bit found; we check next bits */
for (end = *beg + 1;; end++) {
if (end >= *beg + max || end >= boundary
- || reiserfs_test_le_bit(end, bi->bh->b_data)) {
+ || reiserfs_test_le_bit(end, bh->b_data)) {
next = end;
break;
}
@@ -207,12 +216,12 @@
* (end) points to one bit after the window end */
if (end - *beg >= min) { /* it seems we have found window of proper size */
int i;
- reiserfs_prepare_for_journal(s, bi->bh, 1);
+ reiserfs_prepare_for_journal(s, bh, 1);
/* try to set all blocks used checking are they still free */
for (i = *beg; i < end; i++) {
/* It seems that we should not check in journal again. */
if (reiserfs_test_and_set_le_bit
- (i, bi->bh->b_data)) {
+ (i, bh->b_data)) {
/* bit was set by another process
* while we slept in prepare_for_journal() */
PROC_INFO_INC(s, scan_bitmap.stolen);
@@ -224,17 +233,16 @@
/* otherwise we clear all bit were set ... */
while (--i >= *beg)
reiserfs_test_and_clear_le_bit
- (i, bi->bh->b_data);
- reiserfs_restore_prepared_buffer(s,
- bi->
- bh);
+ (i, bh->b_data);
+ reiserfs_restore_prepared_buffer(s, bh);
*beg = org;
/* ... and search again in current block from beginning */
goto cont;
}
}
bi->free_count -= (end - *beg);
- journal_mark_dirty(th, s, bi->bh);
+ journal_mark_dirty(th, s, bh);
+ brelse(bh);
/* free block count calculation */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s),
@@ -383,7 +391,7 @@
{
struct super_block *s = th->t_super;
struct reiserfs_super_block *rs;
- struct buffer_head *sbh;
+ struct buffer_head *sbh, *bmbh;
struct reiserfs_bitmap_info *apbi;
int nr, offset;
@@ -404,16 +412,20 @@
return;
}
- reiserfs_prepare_for_journal(s, apbi[nr].bh, 1);
+ bmbh = apbi[nr].bh;
+ get_bh(bmbh);
+
+ reiserfs_prepare_for_journal(s, bmbh, 1);
/* clear bit for the given block in bit map */
- if (!reiserfs_test_and_clear_le_bit(offset, apbi[nr].bh->b_data)) {
+ if (!reiserfs_test_and_clear_le_bit(offset, bmbh->b_data)) {
reiserfs_warning(s, "vs-4080: reiserfs_free_block: "
"free_block (%s:%lu)[dev:blocknr]: bit already cleared",
reiserfs_bdevname(s), block);
}
apbi[nr].free_count++;
- journal_mark_dirty(th, s, apbi[nr].bh);
+ journal_mark_dirty(th, s, bmbh);
+ brelse(bmbh);
reiserfs_prepare_for_journal(s, sbh, 1);
/* update super block */