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[PATCH] reiserfs: clean up bitmap block buffer head references

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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>
This commit is contained in:
Jeff Mahoney 2006-09-30 23:28:42 -07:00 • committed by Linus Torvalds
parent e1fabd3ccf
commit 0b3dc17bc0
2 changed files with 70 additions and 48 deletions
Download patch file Download diff file Expand all files Collapse all files

60
fs/reiserfs/bitmap.c
View file

@ -59,6 +59,7 @@ static inline void get_bit_address(struct super_block *s,
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 @@ int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
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 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
{
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 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
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 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
/* 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 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
* (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 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
/* 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 @@ static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
{
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 @@ static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
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 */