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authorJeff Mahoney <jeffm@suse.com>2007-10-19 02:39:26 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 14:53:35 -0400
commit4d20851d3757ba5bece263a4c8c5a2bd4983cb5d (patch)
treeac89f9cf860801675e587c38c39fd9e6bd2204da /fs
parent3ee1667042c350003b9d3f35e5666cc8c43ce8aa (diff)
reiserfs: remove first_zero_hint
The first_zero_hint metadata caching was never actually used, and it's of dubious optimization quality. This patch removes it. It doesn't actually shrink the size of the reiserfs_bitmap_info struct, since that doesn't work with block sizes larger than 8K. There was a big fixme in there, and with all the work lately in allowing block size > page size, I might as well kill the fixme as well. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/reiserfs/bitmap.c29
-rw-r--r--fs/reiserfs/resize.c6
2 files changed, 12 insertions, 23 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index f7275176305e..f09a6f6d3ac0 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -273,7 +273,7 @@ static inline int block_group_used(struct super_block *s, u32 id)
273 * to make a better decision. This favors long-term performace gain 273 * to make a better decision. This favors long-term performace gain
274 * with a better on-disk layout vs. a short term gain of skipping the 274 * with a better on-disk layout vs. a short term gain of skipping the
275 * read and potentially having a bad placement. */ 275 * read and potentially having a bad placement. */
276 if (info->first_zero_hint == 0) { 276 if (info->free_count == UINT_MAX) {
277 struct buffer_head *bh = reiserfs_read_bitmap_block(s, bm); 277 struct buffer_head *bh = reiserfs_read_bitmap_block(s, bm);
278 brelse(bh); 278 brelse(bh);
279 } 279 }
@@ -1214,27 +1214,22 @@ void reiserfs_cache_bitmap_metadata(struct super_block *sb,
1214{ 1214{
1215 unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size); 1215 unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size);
1216 1216
1217 info->first_zero_hint = 1 << (sb->s_blocksize_bits + 3); 1217 /* The first bit must ALWAYS be 1 */
1218 BUG_ON(!reiserfs_test_le_bit(0, (unsigned long *)bh->b_data));
1219
1220 info->free_count = 0;
1218 1221
1219 while (--cur >= (unsigned long *)bh->b_data) { 1222 while (--cur >= (unsigned long *)bh->b_data) {
1220 int base = ((char *)cur - bh->b_data) << 3; 1223 int i;
1221 1224
1222 /* 0 and ~0 are special, we can optimize for them */ 1225 /* 0 and ~0 are special, we can optimize for them */
1223 if (*cur == 0) { 1226 if (*cur == 0)
1224 info->first_zero_hint = base;
1225 info->free_count += BITS_PER_LONG; 1227 info->free_count += BITS_PER_LONG;
1226 } else if (*cur != ~0L) { /* A mix, investigate */ 1228 else if (*cur != ~0L) /* A mix, investigate */
1227 int b; 1229 for (i = BITS_PER_LONG - 1; i >= 0; i--)
1228 for (b = BITS_PER_LONG - 1; b >= 0; b--) { 1230 if (!reiserfs_test_le_bit(i, cur))
1229 if (!reiserfs_test_le_bit(b, cur)) {
1230 info->first_zero_hint = base + b;
1231 info->free_count++; 1231 info->free_count++;
1232 }
1233 }
1234 }
1235 } 1232 }
1236 /* The first bit must ALWAYS be 1 */
1237 BUG_ON(info->first_zero_hint == 0);
1238} 1233}
1239 1234
1240struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, 1235struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
@@ -1264,7 +1259,7 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
1264 BUG_ON(!buffer_uptodate(bh)); 1259 BUG_ON(!buffer_uptodate(bh));
1265 BUG_ON(atomic_read(&bh->b_count) == 0); 1260 BUG_ON(atomic_read(&bh->b_count) == 0);
1266 1261
1267 if (info->first_zero_hint == 0) 1262 if (info->free_count == UINT_MAX)
1268 reiserfs_cache_bitmap_metadata(sb, bh, info); 1263 reiserfs_cache_bitmap_metadata(sb, bh, info);
1269 } 1264 }
1270 1265
@@ -1279,7 +1274,7 @@ int reiserfs_init_bitmap_cache(struct super_block *sb)
1279 if (bitmap == NULL) 1274 if (bitmap == NULL)
1280 return -ENOMEM; 1275 return -ENOMEM;
1281 1276
1282 memset(bitmap, 0, sizeof (*bitmap) * SB_BMAP_NR(sb)); 1277 memset(bitmap, 0xff, sizeof(*bitmap) * SB_BMAP_NR(sb));
1283 1278
1284 SB_AP_BITMAP(sb) = bitmap; 1279 SB_AP_BITMAP(sb) = bitmap;
1285 1280
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
index 3bec2f96242a..66f1cda83a81 100644
--- a/fs/reiserfs/resize.c
+++ b/fs/reiserfs/resize.c
@@ -143,7 +143,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
143 mark_buffer_dirty(bh); 143 mark_buffer_dirty(bh);
144 sync_dirty_buffer(bh); 144 sync_dirty_buffer(bh);
145 // update bitmap_info stuff 145 // update bitmap_info stuff
146 bitmap[i].first_zero_hint = 1;
147 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; 146 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
148 brelse(bh); 147 brelse(bh);
149 } 148 }
@@ -173,8 +172,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
173 for (i = block_r; i < s->s_blocksize * 8; i++) 172 for (i = block_r; i < s->s_blocksize * 8; i++)
174 reiserfs_test_and_clear_le_bit(i, bh->b_data); 173 reiserfs_test_and_clear_le_bit(i, bh->b_data);
175 info->free_count += s->s_blocksize * 8 - block_r; 174 info->free_count += s->s_blocksize * 8 - block_r;
176 if (!info->first_zero_hint)
177 info->first_zero_hint = block_r;
178 175
179 journal_mark_dirty(&th, s, bh); 176 journal_mark_dirty(&th, s, bh);
180 brelse(bh); 177 brelse(bh);
@@ -196,9 +193,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
196 brelse(bh); 193 brelse(bh);
197 194
198 info->free_count -= s->s_blocksize * 8 - block_r_new; 195 info->free_count -= s->s_blocksize * 8 - block_r_new;
199 /* Extreme case where last bitmap is the only valid block in itself. */
200 if (!info->free_count)
201 info->first_zero_hint = 0;
202 /* update super */ 196 /* update super */
203 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); 197 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
204 free_blocks = SB_FREE_BLOCKS(s); 198 free_blocks = SB_FREE_BLOCKS(s);