/* * linux/fs/ext3/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@redhat.com), 1993 * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 */ #include #include #include #include #include #include #include #include #include #include #include /* * 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 ext3_read_super). */ /* * Read the inode allocation 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_inode_bitmap (struct super_block * sb, unsigned long block_group, unsigned int bitmap_nr) { struct ext3_group_desc * gdp; struct buffer_head * bh = NULL; int retval = 0; gdp = ext3_get_group_desc (sb, block_group, NULL); if (!gdp) { retval = -EIO; goto error_out; } bh = bread (sb->s_dev, le32_to_cpu(gdp->bg_inode_bitmap), sb->s_blocksize); if (!bh) { ext3_error (sb, "read_inode_bitmap", "Cannot read inode bitmap - " "block_group = %lu, inode_bitmap = %lu", block_group, (unsigned long) gdp->bg_inode_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.ext3_sb.s_inode_bitmap_number[bitmap_nr] = block_group; sb->u.ext3_sb.s_inode_bitmap[bitmap_nr] = bh; return retval; } /* * 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 EXT3_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_inode_bitmap (struct super_block * sb, unsigned int block_group) { struct ext3_sb_info *sbi = EXT3_SB(sb); unsigned long inode_bitmap_number; struct buffer_head * inode_bitmap; int i, j, retval = 0; if (block_group >= sbi->s_groups_count) ext3_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 && sbi->s_inode_bitmap[0] != NULL) return 0; if (sbi->s_groups_count <= EXT3_MAX_GROUP_LOADED) { if (sbi->s_inode_bitmap[block_group]) { if (sbi->s_inode_bitmap_number[block_group] != block_group) ext3_panic(sb, "load_inode_bitmap", "block_group != inode_bitmap_number"); return block_group; } retval = read_inode_bitmap(sb, block_group, block_group); if (retval < 0) return retval; return block_group; } for (i = 0; i < sbi->s_loaded_inode_bitmaps && sbi->s_inode_bitmap_number[i] != block_group; i++) /* do nothing */; if (i < sbi->s_loaded_inode_bitmaps && sbi->s_inode_bitmap_number[i] == block_group) { inode_bitmap_number = sbi->s_inode_bitmap_number[i]; inode_bitmap = sbi->s_inode_bitmap[i]; for (j = i; j > 0; j--) { sbi->s_inode_bitmap_number[j] = sbi->s_inode_bitmap_number[j - 1]; sbi->s_inode_bitmap[j] = sbi->s_inode_bitmap[j - 1]; } sbi->s_inode_bitmap_number[0] = inode_bitmap_number; sbi->s_inode_bitmap[0] = inode_bitmap; /* * There's still one special case here --- if inode_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 (!inode_bitmap) retval = read_inode_bitmap (sb, block_group, 0); } else { if (sbi->s_loaded_inode_bitmaps < EXT3_MAX_GROUP_LOADED) sbi->s_loaded_inode_bitmaps++; else brelse(sbi->s_inode_bitmap[EXT3_MAX_GROUP_LOADED - 1]); for (j = sbi->s_loaded_inode_bitmaps - 1; j > 0; j--) { sbi->s_inode_bitmap_number[j] = sbi->s_inode_bitmap_number[j - 1]; sbi->s_inode_bitmap[j] = sbi->s_inode_bitmap[j - 1]; } retval = read_inode_bitmap (sb, block_group, 0); } return retval; } /* * 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 ext3_free_inode (handle_t *handle, 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; int bitmap_nr; struct ext3_group_desc * gdp; struct ext3_super_block * es; int fatal = 0, err; if (!inode->i_dev) { printk ("ext3_free_inode: inode has no device\n"); return; } if (atomic_read(&inode->i_count) > 1) { printk ("ext3_free_inode: inode has count=%d\n", atomic_read(&inode->i_count)); return; } if (inode->i_nlink) { printk ("ext3_free_inode: inode has nlink=%d\n", inode->i_nlink); return; } if (!sb) { printk("ext3_free_inode: inode on nonexistent device\n"); return; } ino = inode->i_ino; ext3_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. */ DQUOT_INIT(inode); DQUOT_FREE_INODE(inode); DQUOT_DROP(inode); is_directory = S_ISDIR(inode->i_mode); /* Do this BEFORE marking the inode not in use or returning an error */ clear_inode (inode); lock_super (sb); es = sb->u.ext3_sb.s_es; if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { ext3_error (sb, "ext3_free_inode", "reserved or nonexistent inode %lu", ino); goto error_return; } block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb); bitmap_nr = load_inode_bitmap (sb, block_group); if (bitmap_nr < 0) goto error_return; bh = sb->u.ext3_sb.s_inode_bitmap[bitmap_nr]; BUFFER_TRACE(bh, "get_write_access"); fatal = ext3_journal_get_write_access(handle, bh); if (fatal) goto error_return; /* Ok, now we can actually update the inode bitmaps.. */ if (!ext3_clear_bit (bit, bh->b_data)) ext3_error (sb, "ext3_free_inode", "bit already cleared for inode %lu", ino); else { gdp = ext3_get_group_desc (sb, block_group, &bh2); BUFFER_TRACE(bh2, "get_write_access"); fatal = ext3_journal_get_write_access(handle, bh2); if (fatal) goto error_return; BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get write access"); fatal = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh); if (fatal) goto error_return; if (gdp) { gdp->bg_free_inodes_count = cpu_to_le16( le16_to_cpu(gdp->bg_free_inodes_count) + 1); if (is_directory) gdp->bg_used_dirs_count = cpu_to_le16( le16_to_cpu(gdp->bg_used_dirs_count) - 1); } BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, bh2); if (!fatal) fatal = err; es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1); BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh); if (!fatal) fatal = err; } BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, bh); if (!fatal) fatal = err; sb->s_dirt = 1; error_return: ext3_std_error(sb, fatal); 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. */ struct inode * ext3_new_inode (handle_t *handle, const struct inode * dir, int mode) { struct super_block * sb; struct buffer_head * bh; struct buffer_head * bh2; int i, j, avefreei; struct inode * inode; int bitmap_nr; struct ext3_group_desc * gdp; struct ext3_group_desc * tmp; struct ext3_super_block * es; int err = 0; /* Cannot create files in a deleted directory */ if (!dir || !dir->i_nlink) return ERR_PTR(-EPERM); sb = dir->i_sb; inode = new_inode(sb); if (!inode) return ERR_PTR(-ENOMEM); init_rwsem(&inode->u.ext3_i.truncate_sem); lock_super (sb); es = sb->u.ext3_sb.s_es; repeat: gdp = NULL; i = 0; if (S_ISDIR(mode)) { avefreei = le32_to_cpu(es->s_free_inodes_count) / sb->u.ext3_sb.s_groups_count; if (!gdp) { for (j = 0; j < sb->u.ext3_sb.s_groups_count; j++) { struct buffer_head *temp_buffer; tmp = ext3_get_group_desc (sb, j, &temp_buffer); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count) && le16_to_cpu(tmp->bg_free_inodes_count) >= avefreei) { if (!gdp || (le16_to_cpu(tmp->bg_free_blocks_count) > le16_to_cpu(gdp->bg_free_blocks_count))) { i = j; gdp = tmp; bh2 = temp_buffer; } } } } } else { /* * Try to place the inode in its parent directory */ i = dir->u.ext3_i.i_block_group; tmp = ext3_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) gdp = tmp; else { /* * Use a quadratic hash to find a group with a * free inode */ for (j = 1; j < sb->u.ext3_sb.s_groups_count; j <<= 1) { i += j; if (i >= sb->u.ext3_sb.s_groups_count) i -= sb->u.ext3_sb.s_groups_count; tmp = ext3_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) { gdp = tmp; break; } } } if (!gdp) { /* * That failed: try linear search for a free inode */ i = dir->u.ext3_i.i_block_group + 1; for (j = 2; j < sb->u.ext3_sb.s_groups_count; j++) { if (++i >= sb->u.ext3_sb.s_groups_count) i = 0; tmp = ext3_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) { gdp = tmp; break; } } } } err = -ENOSPC; if (!gdp) goto fail; err = -EIO; bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) goto fail; bh = sb->u.ext3_sb.s_inode_bitmap[bitmap_nr]; if ((j = ext3_find_first_zero_bit ((unsigned long *) bh->b_data, EXT3_INODES_PER_GROUP(sb))) < EXT3_INODES_PER_GROUP(sb)) { BUFFER_TRACE(bh, "get_write_access"); err = ext3_journal_get_write_access(handle, bh); if (err) goto fail; if (ext3_set_bit (j, bh->b_data)) { ext3_error (sb, "ext3_new_inode", "bit already set for inode %d", j); goto repeat; } BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, bh); if (err) goto fail; } else { if (le16_to_cpu(gdp->bg_free_inodes_count) != 0) { ext3_error (sb, "ext3_new_inode", "Free inodes count corrupted in group %d", i); /* Is it really ENOSPC? */ err = -ENOSPC; if (sb->s_flags & MS_RDONLY) goto fail; BUFFER_TRACE(bh2, "get_write_access"); err = ext3_journal_get_write_access(handle, bh2); if (err) goto fail; gdp->bg_free_inodes_count = 0; BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, bh2); if (err) goto fail; } goto repeat; } j += i * EXT3_INODES_PER_GROUP(sb) + 1; if (j < EXT3_FIRST_INO(sb) || j > le32_to_cpu(es->s_inodes_count)) { ext3_error (sb, "ext3_new_inode", "reserved inode or inode > inodes count - " "block_group = %d,inode=%d", i, j); err = -EIO; goto fail; } BUFFER_TRACE(bh2, "get_write_access"); err = ext3_journal_get_write_access(handle, bh2); if (err) goto fail; gdp->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1); if (S_ISDIR(mode)) gdp->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1); BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, bh2); if (err) goto fail; BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get_write_access"); err = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh); if (err) goto fail; es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) - 1); BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "call ext3_journal_dirty_metadata"); err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh); sb->s_dirt = 1; if (err) goto fail; 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 = j; /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blksize = PAGE_SIZE; inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->u.ext3_i.i_flags = dir->u.ext3_i.i_flags & ~EXT3_INDEX_FL; if (S_ISLNK(mode)) inode->u.ext3_i.i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL); #ifdef EXT3_FRAGMENTS inode->u.ext3_i.i_faddr = 0; inode->u.ext3_i.i_frag_no = 0; inode->u.ext3_i.i_frag_size = 0; #endif inode->u.ext3_i.i_file_acl = 0; inode->u.ext3_i.i_dir_acl = 0; inode->u.ext3_i.i_dtime = 0; INIT_LIST_HEAD(&inode->u.ext3_i.i_orphan); #ifdef EXT3_PREALLOCATE inode->u.ext3_i.i_prealloc_count = 0; #endif inode->u.ext3_i.i_block_group = i; if (inode->u.ext3_i.i_flags & EXT3_SYNC_FL) inode->i_flags |= S_SYNC; if (IS_SYNC(inode)) handle->h_sync = 1; insert_inode_hash(inode); inode->i_generation = event++; inode->u.ext3_i.i_state = EXT3_STATE_NEW; err = ext3_mark_inode_dirty(handle, inode); if (err) goto fail; 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); } ext3_debug ("allocating inode %lu\n", inode->i_ino); return inode; fail: unlock_super(sb); iput(inode); ext3_std_error(sb, err); return ERR_PTR(err); } /* Verify that we are loading a valid orphan from disk */ struct inode *ext3_orphan_get (struct super_block * sb, ino_t ino) { ino_t max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count); unsigned long block_group; int bit; int bitmap_nr; struct buffer_head *bh; struct inode *inode = NULL; /* Error cases - e2fsck has already cleaned up for us */ if (ino > max_ino) { ext3_warning(sb, __FUNCTION__, "bad orphan ino %ld! e2fsck was run?\n", ino); return NULL; } block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb); if ((bitmap_nr = load_inode_bitmap(sb, block_group)) < 0 || !(bh = EXT3_SB(sb)->s_inode_bitmap[bitmap_nr])) { ext3_warning(sb, __FUNCTION__, "inode bitmap error for orphan %ld\n", ino); return NULL; } /* Having the inode bit set should be a 100% indicator that this * is a valid orphan (no e2fsck run on fs). Orphans also include * inodes that were being truncated, so we can't check i_nlink==0. */ if (!ext3_test_bit(bit, bh->b_data) || !(inode = iget(sb, ino)) || is_bad_inode(inode) || NEXT_ORPHAN(inode) > max_ino) { ext3_warning(sb, __FUNCTION__, "bad orphan inode %ld! e2fsck was run?\n", ino); printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%ld) = %d\n", bit, bh->b_blocknr, ext3_test_bit(bit, bh->b_data)); printk(KERN_NOTICE "inode=%p\n", inode); if (inode) { printk(KERN_NOTICE "is_bad_inode(inode)=%d\n", is_bad_inode(inode)); printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%d\n", NEXT_ORPHAN(inode)); printk(KERN_NOTICE "max_ino=%ld\n", max_ino); } /* Avoid freeing blocks if we got a bad deleted inode */ if (inode && inode->i_nlink == 0) inode->i_blocks = 0; iput(inode); return NULL; } return inode; } unsigned long ext3_count_free_inodes (struct super_block * sb) { #ifdef EXT3FS_DEBUG struct ext3_super_block * es; unsigned long desc_count, bitmap_count, x; int bitmap_nr; struct ext3_group_desc * gdp; int i; lock_super (sb); es = sb->u.ext3_sb.s_es; desc_count = 0; bitmap_count = 0; gdp = NULL; for (i = 0; i < sb->u.ext3_sb.s_groups_count; i++) { gdp = ext3_get_group_desc (sb, i, NULL); if (!gdp) continue; desc_count += le16_to_cpu(gdp->bg_free_inodes_count); bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) continue; x = ext3_count_free (sb->u.ext3_sb.s_inode_bitmap[bitmap_nr], EXT3_INODES_PER_GROUP(sb) / 8); printk ("group %d: stored = %d, counted = %lu\n", i, le16_to_cpu(gdp->bg_free_inodes_count), x); bitmap_count += x; } printk("ext3_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.ext3_sb.s_es->s_free_inodes_count); #endif } #ifdef CONFIG_EXT3_CHECK /* Called at mount-time, super-block is locked */ void ext3_check_inodes_bitmap (struct super_block * sb) { struct ext3_super_block * es; unsigned long desc_count, bitmap_count, x; int bitmap_nr; struct ext3_group_desc * gdp; int i; es = sb->u.ext3_sb.s_es; desc_count = 0; bitmap_count = 0; gdp = NULL; for (i = 0; i < sb->u.ext3_sb.s_groups_count; i++) { gdp = ext3_get_group_desc (sb, i, NULL); if (!gdp) continue; desc_count += le16_to_cpu(gdp->bg_free_inodes_count); bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) continue; x = ext3_count_free (sb->u.ext3_sb.s_inode_bitmap[bitmap_nr], EXT3_INODES_PER_GROUP(sb) / 8); if (le16_to_cpu(gdp->bg_free_inodes_count) != x) ext3_error (sb, "ext3_check_inodes_bitmap", "Wrong free inodes count in group %d, " "stored = %d, counted = %lu", i, le16_to_cpu(gdp->bg_free_inodes_count), x); bitmap_count += x; } if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count) ext3_error (sb, "ext3_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