Skip to content

Commit

Permalink
[PATCH] reiserfs: clean up bitmap block buffer head references
Browse files Browse the repository at this point in the history 
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>
  • Loading branch information
Jeff Mahoney authored and Linus Torvalds committed Oct 1, 2006
1 parent e1fabd3 commit 0b3dc17
Show file tree
Hide file tree
Showing 2 changed files with 71 additions and 49 deletions.
60 changes: 36 additions & 24 deletions fs/reiserfs/bitmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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;

Expand All @@ -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;
}

Expand All @@ -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;
}
Expand All @@ -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);
Expand All @@ -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),
Expand Down Expand Up @@ -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;

Expand All @@ -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 */
Expand Down
60 changes: 35 additions & 25 deletions fs/reiserfs/resize.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
int err = 0;
struct reiserfs_super_block *sb;
struct reiserfs_bitmap_info *bitmap;
struct reiserfs_bitmap_info *info;
struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
struct buffer_head *bh;
struct reiserfs_transaction_handle th;
Expand Down Expand Up @@ -127,16 +128,19 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
* transaction begins, and the new bitmaps don't matter if the
* transaction fails. */
for (i = bmap_nr; i < bmap_nr_new; i++) {
bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);

set_buffer_uptodate(bitmap[i].bh);
mark_buffer_dirty(bitmap[i].bh);
sync_dirty_buffer(bitmap[i].bh);
bh = sb_getblk(s, i * s->s_blocksize * 8);
get_bh(bh);
memset(bh->b_data, 0, sb_blocksize(sb));
reiserfs_test_and_set_le_bit(0, bh->b_data);

set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
// update bitmap_info stuff
bitmap[i].first_zero_hint = 1;
bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
bitmap[i].bh = bh;
brelse(bh);
}
/* free old bitmap blocks array */
SB_AP_BITMAP(s) = bitmap;
Expand All @@ -150,30 +154,36 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
if (err)
return err;

/* correct last bitmap blocks in old and new disk layout */
reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
/* Extend old last bitmap block - new blocks have been made available */
info = SB_AP_BITMAP(s) + bmap_nr - 1;
bh = info->bh;
get_bh(bh);

reiserfs_prepare_for_journal(s, bh, 1);
for (i = block_r; i < s->s_blocksize * 8; i++)
reiserfs_test_and_clear_le_bit(i,
SB_AP_BITMAP(s)[bmap_nr -
1].bh->b_data);
SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
if (!SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
reiserfs_test_and_clear_le_bit(i, bh->b_data);
info->free_count += s->s_blocksize * 8 - block_r;
if (!info->first_zero_hint)
info->first_zero_hint = block_r;

journal_mark_dirty(&th, s, bh);
brelse(bh);

journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
/* Correct new last bitmap block - It may not be full */
info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
bh = info->bh;
get_bh(bh);

reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
reiserfs_prepare_for_journal(s, bh, 1);
for (i = block_r_new; i < s->s_blocksize * 8; i++)
reiserfs_test_and_set_le_bit(i,
SB_AP_BITMAP(s)[bmap_nr_new -
1].bh->b_data);
journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
reiserfs_test_and_set_le_bit(i, bh->b_data);
journal_mark_dirty(&th, s, bh);
brelse(bh);

SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -=
s->s_blocksize * 8 - block_r_new;
info->free_count -= s->s_blocksize * 8 - block_r_new;
/* Extreme case where last bitmap is the only valid block in itself. */
if (!SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count)
SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
if (!info->free_count)
info->first_zero_hint = 0;
/* update super */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
free_blocks = SB_FREE_BLOCKS(s);
Expand Down

0 comments on commit 0b3dc17

Please sign in to comment.