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authorJeff Mahoney <jeffm@suse.com>2006-09-30 23:28:40 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-01 00:39:27 -0700
commite1fabd3ccf02901374bffa434e0af472749a5bd9 (patch)
tree66d618e98020422874a521142ca2da797c9930f3 /fs/reiserfs/bitmap.c
parent8ef386092d7c2891bd7acefb2a87f878f7e9a0d6 (diff)
downloadlinux-e1fabd3ccf02901374bffa434e0af472749a5bd9.tar.bz2
[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 <jeffm@suse.com> Cc: <reiserfs-dev@namesys.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/reiserfs/bitmap.c')
-rw-r--r--fs/reiserfs/bitmap.c40
1 files changed, 25 insertions, 15 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index 4a7dbdee1b6d..1022347a211f 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;