From 0b3dc17bc0c0997bde9f5d7691ec0cae24258cf7 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Sat, 30 Sep 2006 23:28:42 -0700 Subject: [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 Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/reiserfs/bitmap.c | 60 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 36 insertions(+), 24 deletions(-) (limited to 'fs/reiserfs/bitmap.c') 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 @@ 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 */ -- cgit v1.1