| /* |
| * linux/fs/ext2/balloc.c |
| * |
| * Copyright (C) 1992, 1993, 1994, 1995 |
| * Remy Card (card@masi.ibp.fr) |
| * Laboratoire MASI - Institut Blaise Pascal |
| * Universite Pierre et Marie Curie (Paris VI) |
| * |
| * Enhanced block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993 |
| * Big-endian to little-endian byte-swapping/bitmaps by |
| * David S. Miller (davem@caip.rutgers.edu), 1995 |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/fs.h> |
| #include <linux/ext2_fs.h> |
| #include <linux/locks.h> |
| #include <linux/quotaops.h> |
| |
| /* |
| * balloc.c contains the blocks allocation and deallocation routines |
| */ |
| |
| /* |
| * The free blocks are managed by bitmaps. A file system contains several |
| * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap |
| * block for inodes, N blocks for the inode table and data blocks. |
| * |
| * The file system contains group descriptors which are located after the |
| * super block. Each descriptor contains the number of the bitmap block and |
| * the free blocks count in the block. The descriptors are loaded in memory |
| * when a file system is mounted (see ext2_read_super). |
| */ |
| |
| |
| #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) |
| |
| struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, |
| unsigned int block_group, |
| struct buffer_head ** bh) |
| { |
| unsigned long group_desc; |
| unsigned long desc; |
| struct ext2_group_desc * gdp; |
| |
| if (block_group >= sb->u.ext2_sb.s_groups_count) { |
| ext2_error (sb, "ext2_get_group_desc", |
| "block_group >= groups_count - " |
| "block_group = %d, groups_count = %lu", |
| block_group, sb->u.ext2_sb.s_groups_count); |
| |
| return NULL; |
| } |
| |
| group_desc = block_group / EXT2_DESC_PER_BLOCK(sb); |
| desc = block_group % EXT2_DESC_PER_BLOCK(sb); |
| if (!sb->u.ext2_sb.s_group_desc[group_desc]) { |
| ext2_error (sb, "ext2_get_group_desc", |
| "Group descriptor not loaded - " |
| "block_group = %d, group_desc = %lu, desc = %lu", |
| block_group, group_desc, desc); |
| return NULL; |
| } |
| |
| gdp = (struct ext2_group_desc *) |
| sb->u.ext2_sb.s_group_desc[group_desc]->b_data; |
| if (bh) |
| *bh = sb->u.ext2_sb.s_group_desc[group_desc]; |
| return gdp + desc; |
| } |
| |
| /* |
| * Read the bitmap for a given block_group, reading into the specified |
| * slot in the superblock's bitmap cache. |
| * |
| * Return >=0 on success or a -ve error code. |
| */ |
| |
| static int read_block_bitmap (struct super_block * sb, |
| unsigned int block_group, |
| unsigned long bitmap_nr) |
| { |
| struct ext2_group_desc * gdp; |
| struct buffer_head * bh = NULL; |
| int retval = -EIO; |
| |
| gdp = ext2_get_group_desc (sb, block_group, NULL); |
| if (!gdp) |
| goto error_out; |
| retval = 0; |
| bh = bread (sb->s_dev, le32_to_cpu(gdp->bg_block_bitmap), sb->s_blocksize); |
| if (!bh) { |
| ext2_error (sb, "read_block_bitmap", |
| "Cannot read block bitmap - " |
| "block_group = %d, block_bitmap = %lu", |
| block_group, (unsigned long) gdp->bg_block_bitmap); |
| retval = -EIO; |
| } |
| /* |
| * On IO error, just leave a zero in the superblock's block pointer for |
| * this group. The IO will be retried next time. |
| */ |
| error_out: |
| sb->u.ext2_sb.s_block_bitmap_number[bitmap_nr] = block_group; |
| sb->u.ext2_sb.s_block_bitmap[bitmap_nr] = bh; |
| return retval; |
| } |
| |
| /* |
| * load_block_bitmap loads the block bitmap for a blocks group |
| * |
| * It maintains a cache for the last bitmaps loaded. This cache is managed |
| * with a LRU algorithm. |
| * |
| * Notes: |
| * 1/ There is one cache per mounted file system. |
| * 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups, |
| * this function reads the bitmap without maintaining a LRU cache. |
| * |
| * Return the slot used to store the bitmap, or a -ve error code. |
| */ |
| static int __load_block_bitmap (struct super_block * sb, |
| unsigned int block_group) |
| { |
| int i, j, retval = 0; |
| unsigned long block_bitmap_number; |
| struct buffer_head * block_bitmap; |
| |
| if (block_group >= sb->u.ext2_sb.s_groups_count) |
| ext2_panic (sb, "load_block_bitmap", |
| "block_group >= groups_count - " |
| "block_group = %d, groups_count = %lu", |
| block_group, sb->u.ext2_sb.s_groups_count); |
| |
| if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED) { |
| if (sb->u.ext2_sb.s_block_bitmap[block_group]) { |
| if (sb->u.ext2_sb.s_block_bitmap_number[block_group] == |
| block_group) |
| return block_group; |
| ext2_error (sb, "__load_block_bitmap", |
| "block_group != block_bitmap_number"); |
| } |
| retval = read_block_bitmap (sb, block_group, block_group); |
| if (retval < 0) |
| return retval; |
| return block_group; |
| } |
| |
| for (i = 0; i < sb->u.ext2_sb.s_loaded_block_bitmaps && |
| sb->u.ext2_sb.s_block_bitmap_number[i] != block_group; i++) |
| ; |
| if (i < sb->u.ext2_sb.s_loaded_block_bitmaps && |
| sb->u.ext2_sb.s_block_bitmap_number[i] == block_group) { |
| block_bitmap_number = sb->u.ext2_sb.s_block_bitmap_number[i]; |
| block_bitmap = sb->u.ext2_sb.s_block_bitmap[i]; |
| for (j = i; j > 0; j--) { |
| sb->u.ext2_sb.s_block_bitmap_number[j] = |
| sb->u.ext2_sb.s_block_bitmap_number[j - 1]; |
| sb->u.ext2_sb.s_block_bitmap[j] = |
| sb->u.ext2_sb.s_block_bitmap[j - 1]; |
| } |
| sb->u.ext2_sb.s_block_bitmap_number[0] = block_bitmap_number; |
| sb->u.ext2_sb.s_block_bitmap[0] = block_bitmap; |
| |
| /* |
| * There's still one special case here --- if block_bitmap == 0 |
| * then our last attempt to read the bitmap failed and we have |
| * just ended up caching that failure. Try again to read it. |
| */ |
| if (!block_bitmap) |
| retval = read_block_bitmap (sb, block_group, 0); |
| } else { |
| if (sb->u.ext2_sb.s_loaded_block_bitmaps < EXT2_MAX_GROUP_LOADED) |
| sb->u.ext2_sb.s_loaded_block_bitmaps++; |
| else |
| brelse (sb->u.ext2_sb.s_block_bitmap[EXT2_MAX_GROUP_LOADED - 1]); |
| for (j = sb->u.ext2_sb.s_loaded_block_bitmaps - 1; j > 0; j--) { |
| sb->u.ext2_sb.s_block_bitmap_number[j] = |
| sb->u.ext2_sb.s_block_bitmap_number[j - 1]; |
| sb->u.ext2_sb.s_block_bitmap[j] = |
| sb->u.ext2_sb.s_block_bitmap[j - 1]; |
| } |
| retval = read_block_bitmap (sb, block_group, 0); |
| } |
| return retval; |
| } |
| |
| /* |
| * Load the block bitmap for a given block group. First of all do a couple |
| * of fast lookups for common cases and then pass the request onto the guts |
| * of the bitmap loader. |
| * |
| * Return the slot number of the group in the superblock bitmap cache's on |
| * success, or a -ve error code. |
| * |
| * There is still one inconsistency here --- if the number of groups in this |
| * filesystems is <= EXT2_MAX_GROUP_LOADED, then we have no way of |
| * differentiating between a group for which we have never performed a bitmap |
| * IO request, and a group for which the last bitmap read request failed. |
| */ |
| static inline int load_block_bitmap (struct super_block * sb, |
| unsigned int block_group) |
| { |
| int slot; |
| |
| /* |
| * Do the lookup for the slot. First of all, check if we're asking |
| * for the same slot as last time, and did we succeed that last time? |
| */ |
| if (sb->u.ext2_sb.s_loaded_block_bitmaps > 0 && |
| sb->u.ext2_sb.s_block_bitmap_number[0] == block_group && |
| sb->u.ext2_sb.s_block_bitmap[0]) { |
| return 0; |
| } |
| /* |
| * Or can we do a fast lookup based on a loaded group on a filesystem |
| * small enough to be mapped directly into the superblock? |
| */ |
| else if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED && |
| sb->u.ext2_sb.s_block_bitmap_number[block_group] == block_group && |
| sb->u.ext2_sb.s_block_bitmap[block_group]) { |
| slot = block_group; |
| } |
| /* |
| * If not, then do a full lookup for this block group. |
| */ |
| else { |
| slot = __load_block_bitmap (sb, block_group); |
| } |
| |
| /* |
| * <0 means we just got an error |
| */ |
| if (slot < 0) |
| return slot; |
| |
| /* |
| * If it's a valid slot, we may still have cached a previous IO error, |
| * in which case the bh in the superblock cache will be zero. |
| */ |
| if (!sb->u.ext2_sb.s_block_bitmap[slot]) |
| return -EIO; |
| |
| /* |
| * Must have been read in OK to get this far. |
| */ |
| return slot; |
| } |
| |
| /* Free given blocks, update quota and i_blocks field */ |
| void ext2_free_blocks (struct inode * inode, unsigned long block, |
| unsigned long count) |
| { |
| struct buffer_head * bh; |
| struct buffer_head * bh2; |
| unsigned long block_group; |
| unsigned long bit; |
| unsigned long i; |
| int bitmap_nr; |
| unsigned long overflow; |
| struct super_block * sb; |
| struct ext2_group_desc * gdp; |
| struct ext2_super_block * es; |
| |
| sb = inode->i_sb; |
| if (!sb) { |
| printk ("ext2_free_blocks: nonexistent device"); |
| return; |
| } |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| if (block < le32_to_cpu(es->s_first_data_block) || |
| (block + count) > le32_to_cpu(es->s_blocks_count)) { |
| ext2_error (sb, "ext2_free_blocks", |
| "Freeing blocks not in datazone - " |
| "block = %lu, count = %lu", block, count); |
| goto error_return; |
| } |
| |
| ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); |
| |
| do_more: |
| overflow = 0; |
| block_group = (block - le32_to_cpu(es->s_first_data_block)) / |
| EXT2_BLOCKS_PER_GROUP(sb); |
| bit = (block - le32_to_cpu(es->s_first_data_block)) % |
| EXT2_BLOCKS_PER_GROUP(sb); |
| /* |
| * Check to see if we are freeing blocks across a group |
| * boundary. |
| */ |
| if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) { |
| overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb); |
| count -= overflow; |
| } |
| bitmap_nr = load_block_bitmap (sb, block_group); |
| if (bitmap_nr < 0) |
| goto error_return; |
| |
| bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr]; |
| gdp = ext2_get_group_desc (sb, block_group, &bh2); |
| if (!gdp) |
| goto error_return; |
| |
| if (in_range (le32_to_cpu(gdp->bg_block_bitmap), block, count) || |
| in_range (le32_to_cpu(gdp->bg_inode_bitmap), block, count) || |
| in_range (block, le32_to_cpu(gdp->bg_inode_table), |
| sb->u.ext2_sb.s_itb_per_group) || |
| in_range (block + count - 1, le32_to_cpu(gdp->bg_inode_table), |
| sb->u.ext2_sb.s_itb_per_group)) |
| ext2_error (sb, "ext2_free_blocks", |
| "Freeing blocks in system zones - " |
| "Block = %lu, count = %lu", |
| block, count); |
| |
| for (i = 0; i < count; i++) { |
| if (!ext2_clear_bit (bit + i, bh->b_data)) |
| ext2_error (sb, "ext2_free_blocks", |
| "bit already cleared for block %lu", |
| block + i); |
| else { |
| DQUOT_FREE_BLOCK(inode, 1); |
| gdp->bg_free_blocks_count = |
| cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)+1); |
| es->s_free_blocks_count = |
| cpu_to_le32(le32_to_cpu(es->s_free_blocks_count)+1); |
| } |
| } |
| |
| mark_buffer_dirty(bh2); |
| mark_buffer_dirty(sb->u.ext2_sb.s_sbh); |
| |
| mark_buffer_dirty(bh); |
| if (sb->s_flags & MS_SYNCHRONOUS) { |
| ll_rw_block (WRITE, 1, &bh); |
| wait_on_buffer (bh); |
| } |
| if (overflow) { |
| block += count; |
| count = overflow; |
| goto do_more; |
| } |
| sb->s_dirt = 1; |
| error_return: |
| unlock_super (sb); |
| return; |
| } |
| |
| /* |
| * ext2_new_block uses a goal block to assist allocation. If the goal is |
| * free, or there is a free block within 32 blocks of the goal, that block |
| * is allocated. Otherwise a forward search is made for a free block; within |
| * each block group the search first looks for an entire free byte in the block |
| * bitmap, and then for any free bit if that fails. |
| * This function also updates quota and i_blocks field. |
| */ |
| int ext2_new_block (struct inode * inode, unsigned long goal, |
| u32 * prealloc_count, u32 * prealloc_block, int * err) |
| { |
| struct buffer_head * bh; |
| struct buffer_head * bh2; |
| char * p, * r; |
| int i, j, k, tmp; |
| int bitmap_nr; |
| struct super_block * sb; |
| struct ext2_group_desc * gdp; |
| struct ext2_super_block * es; |
| #ifdef EXT2FS_DEBUG |
| static int goal_hits = 0, goal_attempts = 0; |
| #endif |
| *err = -ENOSPC; |
| sb = inode->i_sb; |
| if (!sb) { |
| printk ("ext2_new_block: nonexistent device"); |
| return 0; |
| } |
| |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| if (le32_to_cpu(es->s_free_blocks_count) <= le32_to_cpu(es->s_r_blocks_count) && |
| ((sb->u.ext2_sb.s_resuid != current->fsuid) && |
| (sb->u.ext2_sb.s_resgid == 0 || |
| !in_group_p (sb->u.ext2_sb.s_resgid)) && |
| !capable(CAP_SYS_RESOURCE))) |
| goto out; |
| |
| ext2_debug ("goal=%lu.\n", goal); |
| |
| repeat: |
| /* |
| * First, test whether the goal block is free. |
| */ |
| if (goal < le32_to_cpu(es->s_first_data_block) || |
| goal >= le32_to_cpu(es->s_blocks_count)) |
| goal = le32_to_cpu(es->s_first_data_block); |
| i = (goal - le32_to_cpu(es->s_first_data_block)) / EXT2_BLOCKS_PER_GROUP(sb); |
| gdp = ext2_get_group_desc (sb, i, &bh2); |
| if (!gdp) |
| goto io_error; |
| |
| if (le16_to_cpu(gdp->bg_free_blocks_count) > 0) { |
| j = ((goal - le32_to_cpu(es->s_first_data_block)) % EXT2_BLOCKS_PER_GROUP(sb)); |
| #ifdef EXT2FS_DEBUG |
| if (j) |
| goal_attempts++; |
| #endif |
| bitmap_nr = load_block_bitmap (sb, i); |
| if (bitmap_nr < 0) |
| goto io_error; |
| |
| bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr]; |
| |
| ext2_debug ("goal is at %d:%d.\n", i, j); |
| |
| if (!ext2_test_bit(j, bh->b_data)) { |
| ext2_debug("goal bit allocated, %d hits\n",++goal_hits); |
| goto got_block; |
| } |
| if (j) { |
| /* |
| * The goal was occupied; search forward for a free |
| * block within the next XX blocks. |
| * |
| * end_goal is more or less random, but it has to be |
| * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the |
| * next 64-bit boundary is simple.. |
| */ |
| int end_goal = (j + 63) & ~63; |
| j = ext2_find_next_zero_bit(bh->b_data, end_goal, j); |
| if (j < end_goal) |
| goto got_block; |
| } |
| |
| ext2_debug ("Bit not found near goal\n"); |
| |
| /* |
| * There has been no free block found in the near vicinity |
| * of the goal: do a search forward through the block groups, |
| * searching in each group first for an entire free byte in |
| * the bitmap and then for any free bit. |
| * |
| * Search first in the remainder of the current group; then, |
| * cyclicly search through the rest of the groups. |
| */ |
| p = ((char *) bh->b_data) + (j >> 3); |
| r = memscan(p, 0, (EXT2_BLOCKS_PER_GROUP(sb) - j + 7) >> 3); |
| k = (r - ((char *) bh->b_data)) << 3; |
| if (k < EXT2_BLOCKS_PER_GROUP(sb)) { |
| j = k; |
| goto search_back; |
| } |
| |
| k = ext2_find_next_zero_bit ((unsigned long *) bh->b_data, |
| EXT2_BLOCKS_PER_GROUP(sb), |
| j); |
| if (k < EXT2_BLOCKS_PER_GROUP(sb)) { |
| j = k; |
| goto got_block; |
| } |
| } |
| |
| ext2_debug ("Bit not found in block group %d.\n", i); |
| |
| /* |
| * Now search the rest of the groups. We assume that |
| * i and gdp correctly point to the last group visited. |
| */ |
| for (k = 0; k < sb->u.ext2_sb.s_groups_count; k++) { |
| i++; |
| if (i >= sb->u.ext2_sb.s_groups_count) |
| i = 0; |
| gdp = ext2_get_group_desc (sb, i, &bh2); |
| if (!gdp) |
| goto io_error; |
| if (le16_to_cpu(gdp->bg_free_blocks_count) > 0) |
| break; |
| } |
| if (k >= sb->u.ext2_sb.s_groups_count) |
| goto out; |
| bitmap_nr = load_block_bitmap (sb, i); |
| if (bitmap_nr < 0) |
| goto io_error; |
| |
| bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr]; |
| r = memscan(bh->b_data, 0, EXT2_BLOCKS_PER_GROUP(sb) >> 3); |
| j = (r - bh->b_data) << 3; |
| if (j < EXT2_BLOCKS_PER_GROUP(sb)) |
| goto search_back; |
| else |
| j = ext2_find_first_zero_bit ((unsigned long *) bh->b_data, |
| EXT2_BLOCKS_PER_GROUP(sb)); |
| if (j >= EXT2_BLOCKS_PER_GROUP(sb)) { |
| ext2_error (sb, "ext2_new_block", |
| "Free blocks count corrupted for block group %d", i); |
| goto out; |
| } |
| |
| search_back: |
| /* |
| * We have succeeded in finding a free byte in the block |
| * bitmap. Now search backwards up to 7 bits to find the |
| * start of this group of free blocks. |
| */ |
| for (k = 0; k < 7 && j > 0 && !ext2_test_bit (j - 1, bh->b_data); k++, j--); |
| |
| got_block: |
| |
| ext2_debug ("using block group %d(%d)\n", i, gdp->bg_free_blocks_count); |
| |
| /* |
| * Check quota for allocation of this block. |
| */ |
| if(DQUOT_ALLOC_BLOCK(inode, 1)) { |
| *err = -EDQUOT; |
| goto out; |
| } |
| |
| tmp = j + i * EXT2_BLOCKS_PER_GROUP(sb) + le32_to_cpu(es->s_first_data_block); |
| |
| if (tmp == le32_to_cpu(gdp->bg_block_bitmap) || |
| tmp == le32_to_cpu(gdp->bg_inode_bitmap) || |
| in_range (tmp, le32_to_cpu(gdp->bg_inode_table), |
| sb->u.ext2_sb.s_itb_per_group)) |
| ext2_error (sb, "ext2_new_block", |
| "Allocating block in system zone - " |
| "block = %u", tmp); |
| |
| if (ext2_set_bit (j, bh->b_data)) { |
| ext2_warning (sb, "ext2_new_block", |
| "bit already set for block %d", j); |
| DQUOT_FREE_BLOCK(inode, 1); |
| goto repeat; |
| } |
| |
| ext2_debug ("found bit %d\n", j); |
| |
| /* |
| * Do block preallocation now if required. |
| */ |
| #ifdef EXT2_PREALLOCATE |
| /* Writer: ->i_prealloc* */ |
| if (prealloc_count && !*prealloc_count) { |
| int prealloc_goal; |
| unsigned long next_block = tmp + 1; |
| |
| prealloc_goal = es->s_prealloc_blocks ? |
| es->s_prealloc_blocks : EXT2_DEFAULT_PREALLOC_BLOCKS; |
| |
| *prealloc_block = next_block; |
| /* Writer: end */ |
| for (k = 1; |
| k < prealloc_goal && (j + k) < EXT2_BLOCKS_PER_GROUP(sb); |
| k++, next_block++) { |
| if (DQUOT_PREALLOC_BLOCK(inode, 1)) |
| break; |
| /* Writer: ->i_prealloc* */ |
| if (*prealloc_block + *prealloc_count != next_block || |
| ext2_set_bit (j + k, bh->b_data)) { |
| /* Writer: end */ |
| DQUOT_FREE_BLOCK(inode, 1); |
| break; |
| } |
| (*prealloc_count)++; |
| /* Writer: end */ |
| } |
| /* |
| * As soon as we go for per-group spinlocks we'll need these |
| * done inside the loop above. |
| */ |
| gdp->bg_free_blocks_count = |
| cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - |
| (k - 1)); |
| es->s_free_blocks_count = |
| cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) - |
| (k - 1)); |
| ext2_debug ("Preallocated a further %lu bits.\n", |
| (k - 1)); |
| } |
| #endif |
| |
| j = tmp; |
| |
| mark_buffer_dirty(bh); |
| if (sb->s_flags & MS_SYNCHRONOUS) { |
| ll_rw_block (WRITE, 1, &bh); |
| wait_on_buffer (bh); |
| } |
| |
| if (j >= le32_to_cpu(es->s_blocks_count)) { |
| ext2_error (sb, "ext2_new_block", |
| "block(%d) >= blocks count(%d) - " |
| "block_group = %d, es == %p ",j, |
| le32_to_cpu(es->s_blocks_count), i, es); |
| goto out; |
| } |
| |
| ext2_debug ("allocating block %d. " |
| "Goal hits %d of %d.\n", j, goal_hits, goal_attempts); |
| |
| gdp->bg_free_blocks_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1); |
| mark_buffer_dirty(bh2); |
| es->s_free_blocks_count = cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) - 1); |
| mark_buffer_dirty(sb->u.ext2_sb.s_sbh); |
| sb->s_dirt = 1; |
| unlock_super (sb); |
| *err = 0; |
| return j; |
| |
| io_error: |
| *err = -EIO; |
| out: |
| unlock_super (sb); |
| return 0; |
| |
| } |
| |
| unsigned long ext2_count_free_blocks (struct super_block * sb) |
| { |
| #ifdef EXT2FS_DEBUG |
| struct ext2_super_block * es; |
| unsigned long desc_count, bitmap_count, x; |
| int bitmap_nr; |
| struct ext2_group_desc * gdp; |
| int i; |
| |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| desc_count = 0; |
| bitmap_count = 0; |
| gdp = NULL; |
| for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { |
| gdp = ext2_get_group_desc (sb, i, NULL); |
| if (!gdp) |
| continue; |
| desc_count += le16_to_cpu(gdp->bg_free_blocks_count); |
| bitmap_nr = load_block_bitmap (sb, i); |
| if (bitmap_nr < 0) |
| continue; |
| |
| x = ext2_count_free (sb->u.ext2_sb.s_block_bitmap[bitmap_nr], |
| sb->s_blocksize); |
| printk ("group %d: stored = %d, counted = %lu\n", |
| i, le16_to_cpu(gdp->bg_free_blocks_count), x); |
| bitmap_count += x; |
| } |
| printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n", |
| le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count); |
| unlock_super (sb); |
| return bitmap_count; |
| #else |
| return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_blocks_count); |
| #endif |
| } |
| |
| static inline int block_in_use (unsigned long block, |
| struct super_block * sb, |
| unsigned char * map) |
| { |
| return ext2_test_bit ((block - le32_to_cpu(sb->u.ext2_sb.s_es->s_first_data_block)) % |
| EXT2_BLOCKS_PER_GROUP(sb), map); |
| } |
| |
| static inline int test_root(int a, int b) |
| { |
| if (a == 0) |
| return 1; |
| while (1) { |
| if (a == 1) |
| return 1; |
| if (a % b) |
| return 0; |
| a = a / b; |
| } |
| } |
| |
| int ext2_group_sparse(int group) |
| { |
| return (test_root(group, 3) || test_root(group, 5) || |
| test_root(group, 7)); |
| } |
| |
| /** |
| * ext2_bg_has_super - number of blocks used by the superblock in group |
| * @sb: superblock for filesystem |
| * @group: group number to check |
| * |
| * Return the number of blocks used by the superblock (primary or backup) |
| * in this group. Currently this will be only 0 or 1. |
| */ |
| int ext2_bg_has_super(struct super_block *sb, int group) |
| { |
| if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& |
| !ext2_group_sparse(group)) |
| return 0; |
| return 1; |
| } |
| |
| /** |
| * ext2_bg_num_gdb - number of blocks used by the group table in group |
| * @sb: superblock for filesystem |
| * @group: group number to check |
| * |
| * Return the number of blocks used by the group descriptor table |
| * (primary or backup) in this group. In the future there may be a |
| * different number of descriptor blocks in each group. |
| */ |
| unsigned long ext2_bg_num_gdb(struct super_block *sb, int group) |
| { |
| if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& |
| !ext2_group_sparse(group)) |
| return 0; |
| return EXT2_SB(sb)->s_gdb_count; |
| } |
| |
| #ifdef CONFIG_EXT2_CHECK |
| /* Called at mount-time, super-block is locked */ |
| void ext2_check_blocks_bitmap (struct super_block * sb) |
| { |
| struct buffer_head * bh; |
| struct ext2_super_block * es; |
| unsigned long desc_count, bitmap_count, x, j; |
| unsigned long desc_blocks; |
| int bitmap_nr; |
| struct ext2_group_desc * gdp; |
| int i; |
| |
| es = sb->u.ext2_sb.s_es; |
| desc_count = 0; |
| bitmap_count = 0; |
| gdp = NULL; |
| for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { |
| gdp = ext2_get_group_desc (sb, i, NULL); |
| if (!gdp) |
| continue; |
| desc_count += le16_to_cpu(gdp->bg_free_blocks_count); |
| bitmap_nr = load_block_bitmap (sb, i); |
| if (bitmap_nr < 0) |
| continue; |
| |
| bh = EXT2_SB(sb)->s_block_bitmap[bitmap_nr]; |
| |
| if (ext2_bg_has_super(sb, i) && !ext2_test_bit(0, bh->b_data)) |
| ext2_error(sb, __FUNCTION__, |
| "Superblock in group %d is marked free", i); |
| |
| desc_blocks = ext2_bg_num_gdb(sb, i); |
| for (j = 0; j < desc_blocks; j++) |
| if (!ext2_test_bit(j + 1, bh->b_data)) |
| ext2_error(sb, __FUNCTION__, |
| "Descriptor block #%ld in group " |
| "%d is marked free", j, i); |
| |
| if (!block_in_use (le32_to_cpu(gdp->bg_block_bitmap), sb, bh->b_data)) |
| ext2_error (sb, "ext2_check_blocks_bitmap", |
| "Block bitmap for group %d is marked free", |
| i); |
| |
| if (!block_in_use (le32_to_cpu(gdp->bg_inode_bitmap), sb, bh->b_data)) |
| ext2_error (sb, "ext2_check_blocks_bitmap", |
| "Inode bitmap for group %d is marked free", |
| i); |
| |
| for (j = 0; j < sb->u.ext2_sb.s_itb_per_group; j++) |
| if (!block_in_use (le32_to_cpu(gdp->bg_inode_table) + j, sb, bh->b_data)) |
| ext2_error (sb, "ext2_check_blocks_bitmap", |
| "Block #%ld of the inode table in " |
| "group %d is marked free", j, i); |
| |
| x = ext2_count_free (bh, sb->s_blocksize); |
| if (le16_to_cpu(gdp->bg_free_blocks_count) != x) |
| ext2_error (sb, "ext2_check_blocks_bitmap", |
| "Wrong free blocks count for group %d, " |
| "stored = %d, counted = %lu", i, |
| le16_to_cpu(gdp->bg_free_blocks_count), x); |
| bitmap_count += x; |
| } |
| if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count) |
| ext2_error (sb, "ext2_check_blocks_bitmap", |
| "Wrong free blocks count in super block, " |
| "stored = %lu, counted = %lu", |
| (unsigned long) le32_to_cpu(es->s_free_blocks_count), bitmap_count); |
| } |
| #endif |