diff options
Diffstat (limited to 'fs/reiserfs/bitmap.c')
| -rw-r--r-- | fs/reiserfs/bitmap.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c index 44d9410e9d6a..abdd6d9c4558 100644 --- a/fs/reiserfs/bitmap.c +++ b/fs/reiserfs/bitmap.c @@ -9,6 +9,7 @@ #include <linux/buffer_head.h> #include <linux/kernel.h> #include <linux/pagemap.h> +#include <linux/vmalloc.h> #include <linux/reiserfs_fs_sb.h> #include <linux/reiserfs_fs_i.h> #include <linux/quotaops.h> @@ -1285,3 +1286,90 @@ int reiserfs_can_fit_pages(struct super_block *sb /* superblock of filesystem return space > 0 ? space : 0; } + +void reiserfs_cache_bitmap_metadata(struct super_block *sb, + struct buffer_head *bh, + struct reiserfs_bitmap_info *info) +{ + unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size); + + info->first_zero_hint = 1 << (sb->s_blocksize_bits + 3); + + while (--cur >= (unsigned long *)bh->b_data) { + int base = ((char *)cur - bh->b_data) << 3; + + /* 0 and ~0 are special, we can optimize for them */ + if (*cur == 0) { + info->first_zero_hint = base; + info->free_count += BITS_PER_LONG; + } else if (*cur != ~0L) { /* A mix, investigate */ + int b; + for (b = BITS_PER_LONG - 1; b >= 0; b--) { + if (!reiserfs_test_le_bit(b, cur)) { + info->first_zero_hint = base + b; + info->free_count++; + } + } + } + } + /* The first bit must ALWAYS be 1 */ + BUG_ON(info->first_zero_hint == 0); +} + +struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, + unsigned int bitmap) +{ + b_blocknr_t block = (sb->s_blocksize << 3) * bitmap; + struct buffer_head *bh; + + /* Way old format filesystems had the bitmaps packed up front. + * I doubt there are any of these left, but just in case... */ + if (unlikely(test_bit(REISERFS_OLD_FORMAT, + &(REISERFS_SB(sb)->s_properties)))) + block = REISERFS_SB(sb)->s_sbh->b_blocknr + 1 + bitmap; + else if (bitmap == 0) + block = (REISERFS_DISK_OFFSET_IN_BYTES >> sb->s_blocksize_bits) + 1; + + bh = sb_getblk(sb, block); + if (!buffer_uptodate(bh)) + ll_rw_block(READ, 1, &bh); + + return bh; +} + +int reiserfs_init_bitmap_cache(struct super_block *sb) +{ + struct reiserfs_bitmap_info *bitmap; + int i; + + bitmap = vmalloc(sizeof (*bitmap) * SB_BMAP_NR(sb)); + if (bitmap == NULL) + return -ENOMEM; + + memset(bitmap, 0, sizeof (*bitmap) * SB_BMAP_NR(sb)); + + for (i = 0; i < SB_BMAP_NR(sb); i++) + bitmap[i].bh = reiserfs_read_bitmap_block(sb, i); + + /* make sure we have them all */ + for (i = 0; i < SB_BMAP_NR(sb); i++) { + wait_on_buffer(bitmap[i].bh); + if (!buffer_uptodate(bitmap[i].bh)) { + reiserfs_warning(sb, "sh-2029: %s: " + "bitmap block (#%lu) reading failed", + __FUNCTION__, bitmap[i].bh->b_blocknr); + for (i = 0; i < SB_BMAP_NR(sb); i++) + brelse(bitmap[i].bh); + vfree(bitmap); + return -EIO; + } + } + + /* Cache the info on the bitmaps before we get rolling */ + for (i = 0; i < SB_BMAP_NR(sb); i++) + reiserfs_cache_bitmap_metadata(sb, bitmap[i].bh, &bitmap[i]); + + SB_AP_BITMAP(sb) = bitmap; + + return 0; +} |
