| /* |
| * linux/fs/ext2/ialloc.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) |
| * |
| * BSD ufs-inspired inode and directory 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> |
| |
| |
| /* |
| * ialloc.c contains the inodes allocation and deallocation routines |
| */ |
| |
| /* |
| * The free inodes 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). |
| */ |
| |
| |
| /* |
| * Read the inode allocation bitmap for a given block_group, reading |
| * into the specified slot in the superblock's bitmap cache. |
| * |
| * Return buffer_head of bitmap on success or NULL. |
| */ |
| static struct buffer_head *read_inode_bitmap (struct super_block * sb, |
| unsigned long block_group) |
| { |
| struct ext2_group_desc *desc; |
| struct buffer_head *bh = NULL; |
| |
| desc = ext2_get_group_desc(sb, block_group, NULL); |
| if (!desc) |
| goto error_out; |
| |
| bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap)); |
| if (!bh) |
| ext2_error (sb, "read_inode_bitmap", |
| "Cannot read inode bitmap - " |
| "block_group = %lu, inode_bitmap = %lu", |
| block_group, (unsigned long) desc->bg_inode_bitmap); |
| error_out: |
| return bh; |
| } |
| |
| /* |
| * load_inode_bitmap loads the inode 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 buffer_head of the bitmap or the ERR_PTR(error) |
| */ |
| static struct buffer_head *load_inode_bitmap (struct super_block * sb, |
| unsigned int block_group) |
| { |
| int i, slot = 0; |
| struct ext2_sb_info *sbi = &sb->u.ext2_sb; |
| struct buffer_head *bh = sbi->s_inode_bitmap[0]; |
| |
| if (block_group >= sbi->s_groups_count) |
| ext2_panic (sb, "load_inode_bitmap", |
| "block_group >= groups_count - " |
| "block_group = %d, groups_count = %lu", |
| block_group, sbi->s_groups_count); |
| |
| if (sbi->s_loaded_inode_bitmaps > 0 && |
| sbi->s_inode_bitmap_number[0] == block_group && bh) |
| goto found; |
| |
| if (sbi->s_groups_count <= EXT2_MAX_GROUP_LOADED) { |
| slot = block_group; |
| bh = sbi->s_inode_bitmap[slot]; |
| if (!bh) |
| goto read_it; |
| if (sbi->s_inode_bitmap_number[slot] == slot) |
| goto found; |
| ext2_panic (sb, "load_inode_bitmap", |
| "block_group != inode_bitmap_number"); |
| } |
| |
| bh = NULL; |
| for (i = 0; i < sbi->s_loaded_inode_bitmaps && |
| sbi->s_inode_bitmap_number[i] != block_group; |
| i++) |
| ; |
| if (i < sbi->s_loaded_inode_bitmaps) |
| bh = sbi->s_inode_bitmap[i]; |
| else if (sbi->s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED) |
| sbi->s_loaded_inode_bitmaps++; |
| else |
| brelse (sbi->s_inode_bitmap[--i]); |
| |
| while (i--) { |
| sbi->s_inode_bitmap_number[i+1] = sbi->s_inode_bitmap_number[i]; |
| sbi->s_inode_bitmap[i+1] = sbi->s_inode_bitmap[i]; |
| } |
| |
| read_it: |
| if (!bh) |
| bh = read_inode_bitmap (sb, block_group); |
| sbi->s_inode_bitmap_number[slot] = block_group; |
| sbi->s_inode_bitmap[slot] = bh; |
| if (!bh) |
| return ERR_PTR(-EIO); |
| found: |
| return bh; |
| } |
| |
| /* |
| * NOTE! When we get the inode, we're the only people |
| * that have access to it, and as such there are no |
| * race conditions we have to worry about. The inode |
| * is not on the hash-lists, and it cannot be reached |
| * through the filesystem because the directory entry |
| * has been deleted earlier. |
| * |
| * HOWEVER: we must make sure that we get no aliases, |
| * which means that we have to call "clear_inode()" |
| * _before_ we mark the inode not in use in the inode |
| * bitmaps. Otherwise a newly created file might use |
| * the same inode number (not actually the same pointer |
| * though), and then we'd have two inodes sharing the |
| * same inode number and space on the harddisk. |
| */ |
| void ext2_free_inode (struct inode * inode) |
| { |
| struct super_block * sb = inode->i_sb; |
| int is_directory; |
| unsigned long ino; |
| struct buffer_head * bh; |
| struct buffer_head * bh2; |
| unsigned long block_group; |
| unsigned long bit; |
| struct ext2_group_desc * desc; |
| struct ext2_super_block * es; |
| |
| ino = inode->i_ino; |
| ext2_debug ("freeing inode %lu\n", ino); |
| |
| /* |
| * Note: we must free any quota before locking the superblock, |
| * as writing the quota to disk may need the lock as well. |
| */ |
| if (!is_bad_inode(inode)) { |
| /* Quota is already initialized in iput() */ |
| DQUOT_FREE_INODE(inode); |
| DQUOT_DROP(inode); |
| } |
| |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| is_directory = S_ISDIR(inode->i_mode); |
| |
| /* Do this BEFORE marking the inode not in use or returning an error */ |
| clear_inode (inode); |
| |
| if (ino < EXT2_FIRST_INO(sb) || |
| ino > le32_to_cpu(es->s_inodes_count)) { |
| ext2_error (sb, "ext2_free_inode", |
| "reserved or nonexistent inode %lu", ino); |
| goto error_return; |
| } |
| block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); |
| bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb); |
| bh = load_inode_bitmap (sb, block_group); |
| if (IS_ERR(bh)) |
| goto error_return; |
| |
| /* Ok, now we can actually update the inode bitmaps.. */ |
| if (!ext2_clear_bit (bit, bh->b_data)) |
| ext2_error (sb, "ext2_free_inode", |
| "bit already cleared for inode %lu", ino); |
| else { |
| desc = ext2_get_group_desc (sb, block_group, &bh2); |
| if (desc) { |
| desc->bg_free_inodes_count = |
| cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1); |
| if (is_directory) |
| desc->bg_used_dirs_count = |
| cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1); |
| } |
| mark_buffer_dirty(bh2); |
| es->s_free_inodes_count = |
| cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1); |
| 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); |
| } |
| sb->s_dirt = 1; |
| error_return: |
| unlock_super (sb); |
| } |
| |
| /* |
| * There are two policies for allocating an inode. If the new inode is |
| * a directory, then a forward search is made for a block group with both |
| * free space and a low directory-to-inode ratio; if that fails, then of |
| * the groups with above-average free space, that group with the fewest |
| * directories already is chosen. |
| * |
| * For other inodes, search forward from the parent directory\'s block |
| * group to find a free inode. |
| */ |
| |
| static int find_group_dir(struct super_block *sb, int parent_group) |
| { |
| struct ext2_super_block * es = sb->u.ext2_sb.s_es; |
| int ngroups = sb->u.ext2_sb.s_groups_count; |
| int avefreei = le32_to_cpu(es->s_free_inodes_count) / ngroups; |
| struct ext2_group_desc *desc, *best_desc = NULL; |
| struct buffer_head *bh, *best_bh = NULL; |
| int group, best_group = -1; |
| |
| for (group = 0; group < ngroups; group++) { |
| desc = ext2_get_group_desc (sb, group, &bh); |
| if (!desc || !desc->bg_free_inodes_count) |
| continue; |
| if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) |
| continue; |
| if (!best_desc || |
| (le16_to_cpu(desc->bg_free_blocks_count) > |
| le16_to_cpu(best_desc->bg_free_blocks_count))) { |
| best_group = group; |
| best_desc = desc; |
| best_bh = bh; |
| } |
| } |
| if (!best_desc) |
| return -1; |
| best_desc->bg_free_inodes_count = |
| cpu_to_le16(le16_to_cpu(best_desc->bg_free_inodes_count) - 1); |
| best_desc->bg_used_dirs_count = |
| cpu_to_le16(le16_to_cpu(best_desc->bg_used_dirs_count) + 1); |
| mark_buffer_dirty(best_bh); |
| return best_group; |
| } |
| |
| static int find_group_other(struct super_block *sb, int parent_group) |
| { |
| int ngroups = sb->u.ext2_sb.s_groups_count; |
| struct ext2_group_desc *desc; |
| struct buffer_head *bh; |
| int group, i; |
| |
| /* |
| * Try to place the inode in its parent directory |
| */ |
| group = parent_group; |
| desc = ext2_get_group_desc (sb, group, &bh); |
| if (desc && le16_to_cpu(desc->bg_free_inodes_count)) |
| goto found; |
| |
| /* |
| * Use a quadratic hash to find a group with a |
| * free inode |
| */ |
| for (i = 1; i < ngroups; i <<= 1) { |
| group += i; |
| if (group >= ngroups) |
| group -= ngroups; |
| desc = ext2_get_group_desc (sb, group, &bh); |
| if (desc && le16_to_cpu(desc->bg_free_inodes_count)) |
| goto found; |
| } |
| |
| /* |
| * That failed: try linear search for a free inode |
| */ |
| group = parent_group + 1; |
| for (i = 2; i < ngroups; i++) { |
| if (++group >= ngroups) |
| group = 0; |
| desc = ext2_get_group_desc (sb, group, &bh); |
| if (desc && le16_to_cpu(desc->bg_free_inodes_count)) |
| goto found; |
| } |
| |
| return -1; |
| |
| found: |
| desc->bg_free_inodes_count = |
| cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) - 1); |
| mark_buffer_dirty(bh); |
| return group; |
| } |
| |
| struct inode * ext2_new_inode (const struct inode * dir, int mode) |
| { |
| struct super_block * sb; |
| struct buffer_head * bh; |
| struct buffer_head * bh2; |
| int group, i; |
| ino_t ino; |
| struct inode * inode; |
| struct ext2_group_desc * desc; |
| struct ext2_super_block * es; |
| int err; |
| |
| sb = dir->i_sb; |
| inode = new_inode(sb); |
| if (!inode) |
| return ERR_PTR(-ENOMEM); |
| |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| repeat: |
| if (S_ISDIR(mode)) |
| group = find_group_dir(sb, dir->u.ext2_i.i_block_group); |
| else |
| group = find_group_other(sb, dir->u.ext2_i.i_block_group); |
| |
| err = -ENOSPC; |
| if (group == -1) |
| goto fail; |
| |
| err = -EIO; |
| bh = load_inode_bitmap (sb, group); |
| if (IS_ERR(bh)) |
| goto fail2; |
| |
| i = ext2_find_first_zero_bit ((unsigned long *) bh->b_data, |
| EXT2_INODES_PER_GROUP(sb)); |
| if (i >= EXT2_INODES_PER_GROUP(sb)) |
| goto bad_count; |
| ext2_set_bit (i, bh->b_data); |
| |
| mark_buffer_dirty(bh); |
| if (sb->s_flags & MS_SYNCHRONOUS) { |
| ll_rw_block (WRITE, 1, &bh); |
| wait_on_buffer (bh); |
| } |
| |
| ino = group * EXT2_INODES_PER_GROUP(sb) + i + 1; |
| if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { |
| ext2_error (sb, "ext2_new_inode", |
| "reserved inode or inode > inodes count - " |
| "block_group = %d,inode=%ld", group, ino); |
| err = -EIO; |
| goto fail2; |
| } |
| |
| es->s_free_inodes_count = |
| cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) - 1); |
| mark_buffer_dirty(sb->u.ext2_sb.s_sbh); |
| sb->s_dirt = 1; |
| inode->i_uid = current->fsuid; |
| if (test_opt (sb, GRPID)) |
| inode->i_gid = dir->i_gid; |
| else if (dir->i_mode & S_ISGID) { |
| inode->i_gid = dir->i_gid; |
| if (S_ISDIR(mode)) |
| mode |= S_ISGID; |
| } else |
| inode->i_gid = current->fsgid; |
| inode->i_mode = mode; |
| |
| inode->i_ino = ino; |
| inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ |
| inode->i_blocks = 0; |
| inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| inode->u.ext2_i.i_new_inode = 1; |
| inode->u.ext2_i.i_flags = dir->u.ext2_i.i_flags; |
| if (S_ISLNK(mode)) |
| inode->u.ext2_i.i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL); |
| inode->u.ext2_i.i_block_group = group; |
| if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL) |
| inode->i_flags |= S_SYNC; |
| insert_inode_hash(inode); |
| inode->i_generation = event++; |
| mark_inode_dirty(inode); |
| |
| unlock_super (sb); |
| if(DQUOT_ALLOC_INODE(inode)) { |
| DQUOT_DROP(inode); |
| inode->i_flags |= S_NOQUOTA; |
| inode->i_nlink = 0; |
| iput(inode); |
| return ERR_PTR(-EDQUOT); |
| } |
| ext2_debug ("allocating inode %lu\n", inode->i_ino); |
| return inode; |
| |
| fail2: |
| desc = ext2_get_group_desc (sb, group, &bh2); |
| desc->bg_free_inodes_count = |
| cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1); |
| if (S_ISDIR(mode)) |
| desc->bg_used_dirs_count = |
| cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1); |
| mark_buffer_dirty(bh2); |
| fail: |
| unlock_super(sb); |
| make_bad_inode(inode); |
| iput(inode); |
| return ERR_PTR(err); |
| |
| bad_count: |
| ext2_error (sb, "ext2_new_inode", |
| "Free inodes count corrupted in group %d", |
| group); |
| /* Is it really ENOSPC? */ |
| err = -ENOSPC; |
| if (sb->s_flags & MS_RDONLY) |
| goto fail; |
| |
| desc = ext2_get_group_desc (sb, group, &bh2); |
| desc->bg_free_inodes_count = 0; |
| mark_buffer_dirty(bh2); |
| goto repeat; |
| } |
| |
| unsigned long ext2_count_free_inodes (struct super_block * sb) |
| { |
| #ifdef EXT2FS_DEBUG |
| struct ext2_super_block * es; |
| unsigned long desc_count = 0, bitmap_count = 0; |
| int i; |
| |
| lock_super (sb); |
| es = sb->u.ext2_sb.s_es; |
| for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { |
| struct ext2_group_desc *desc = ext2_get_group_desc (sb, i, NULL); |
| struct buffer_head *bh; |
| unsigned x; |
| |
| if (!desc) |
| continue; |
| desc_count += le16_to_cpu(desc->bg_free_inodes_count); |
| bh = load_inode_bitmap (sb, i); |
| if (IS_ERR(bh)) |
| continue; |
| |
| x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8); |
| printk ("group %d: stored = %d, counted = %lu\n", |
| i, le16_to_cpu(desc->bg_free_inodes_count), x); |
| bitmap_count += x; |
| } |
| printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", |
| le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); |
| unlock_super (sb); |
| return desc_count; |
| #else |
| return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_inodes_count); |
| #endif |
| } |
| |
| #ifdef CONFIG_EXT2_CHECK |
| /* Called at mount-time, super-block is locked */ |
| void ext2_check_inodes_bitmap (struct super_block * sb) |
| { |
| struct ext2_super_block * es = sb->u.ext2_sb.s_es; |
| unsigned long desc_count = 0, bitmap_count = 0; |
| int i; |
| |
| for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { |
| struct ext2_group_desc *desc = ext2_get_group_desc(sb, i, NULL); |
| struct buffer_head *bh; |
| unsigned x; |
| |
| if (!desc) |
| continue; |
| desc_count += le16_to_cpu(desc->bg_free_inodes_count); |
| bh = load_inode_bitmap (sb, i); |
| if (IS_ERR(bh)) |
| continue; |
| |
| x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8); |
| if (le16_to_cpu(desc->bg_free_inodes_count) != x) |
| ext2_error (sb, "ext2_check_inodes_bitmap", |
| "Wrong free inodes count in group %d, " |
| "stored = %d, counted = %lu", i, |
| le16_to_cpu(desc->bg_free_inodes_count), x); |
| bitmap_count += x; |
| } |
| if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count) |
| ext2_error (sb, "ext2_check_inodes_bitmap", |
| "Wrong free inodes count in super block, " |
| "stored = %lu, counted = %lu", |
| (unsigned long)le32_to_cpu(es->s_free_inodes_count), |
| bitmap_count); |
| } |
| #endif |