From e1fabd3ccf02901374bffa434e0af472749a5bd9 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Sat, 30 Sep 2006 23:28:40 -0700 Subject: [PATCH] reiserfs: fix is_reusable bitmap check to not traverse the bitmap info array There is a check in is_reusable to determine if a particular block is a bitmap block. It verifies this by going through the array of bitmap block buffer heads and comparing the block number to each one. Bitmap blocks are at defined locations on the disk in both old and current formats. Simply checking against the known good values is enough. This is a trivial optimization for a non-production codepath, but this is the first in a series of patches that will ultimately remove the buffer heads from that array. Signed-off-by: Jeff Mahoney Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/reiserfs/bitmap.c | 40 +++++++++++++++++++++++++--------------- fs/reiserfs/super.c | 2 ++ 2 files changed, 27 insertions(+), 15 deletions(-) (limited to 'fs') diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c index 4a7dbdee1b6..1022347a211 100644 --- a/fs/reiserfs/bitmap.c +++ b/fs/reiserfs/bitmap.c @@ -50,16 +50,15 @@ static inline void get_bit_address(struct super_block *s, { /* It is in the bitmap block number equal to the block * number divided by the number of bits in a block. */ - *bmap_nr = block / (s->s_blocksize << 3); + *bmap_nr = block >> (s->s_blocksize_bits + 3); /* Within that bitmap block it is located at bit offset *offset. */ *offset = block & ((s->s_blocksize << 3) - 1); - return; } #ifdef CONFIG_REISERFS_CHECK int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value) { - int i, j; + int bmap, offset; if (block == 0 || block >= SB_BLOCK_COUNT(s)) { reiserfs_warning(s, @@ -68,34 +67,45 @@ int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value) return 0; } - /* it can't be one of the bitmap blocks */ - for (i = 0; i < SB_BMAP_NR(s); i++) - if (block == SB_AP_BITMAP(s)[i].bh->b_blocknr) { + get_bit_address(s, block, &bmap, &offset); + + /* Old format filesystem? Unlikely, but the bitmaps are all up front so + * we need to account for it. */ + if (unlikely(test_bit(REISERFS_OLD_FORMAT, + &(REISERFS_SB(s)->s_properties)))) { + b_blocknr_t bmap1 = REISERFS_SB(s)->s_sbh->b_blocknr + 1; + if (block >= bmap1 && block <= bmap1 + SB_BMAP_NR(s)) { + reiserfs_warning(s, "vs: 4019: is_reusable: " + "bitmap block %lu(%u) can't be freed or reused", + block, SB_BMAP_NR(s)); + return 0; + } + } else { + if (offset == 0) { reiserfs_warning(s, "vs: 4020: is_reusable: " "bitmap block %lu(%u) can't be freed or reused", block, SB_BMAP_NR(s)); return 0; } + } - get_bit_address(s, block, &i, &j); - - if (i >= SB_BMAP_NR(s)) { + if (bmap >= SB_BMAP_NR(s)) { reiserfs_warning(s, "vs-4030: is_reusable: there is no so many bitmap blocks: " - "block=%lu, bitmap_nr=%d", block, i); + "block=%lu, bitmap_nr=%d", block, bmap); return 0; } if ((bit_value == 0 && - reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data)) || + reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data)) || (bit_value == 1 && - reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data) == 0)) { + reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data) == 0)) { reiserfs_warning(s, "vs-4040: is_reusable: corresponding bit of block %lu does not " - "match required value (i==%d, j==%d) test_bit==%d", - block, i, j, reiserfs_test_le_bit(j, + "match required value (bmap==%d, offset==%d) test_bit==%d", + block, bmap, offset, reiserfs_test_le_bit(offset, SB_AP_BITMAP - (s)[i].bh-> + (s)[bmap].bh-> b_data)); return 0; diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index 80fc3b32802..db2c581df76 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -1818,6 +1818,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent) if (is_reiserfs_3_5(rs) || (is_reiserfs_jr(rs) && SB_VERSION(s) == REISERFS_VERSION_1)) set_bit(REISERFS_3_5, &(sbi->s_properties)); + else if (old_format) + set_bit(REISERFS_OLD_FORMAT, &(sbi->s_properties)); else set_bit(REISERFS_3_6, &(sbi->s_properties)); -- cgit v1.2.3