ext4: let ext4_group_add() use common code (61f296cc) · Commits · EulixOS / Software / Kernel

fs/ext4/resize.c

+10 −299

Original line number	Diff line number	Diff line
		@@ -594,137 +594,6 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
		return err;
		}

		/*
		* Set up the block and inode bitmaps, and the inode table for the new group.
		* This doesn't need to be part of the main transaction, since we are only
		* changing blocks outside the actual filesystem. We still do journaling to
		* ensure the recovery is correct in case of a failure just after resize.
		* If any part of this fails, we simply abort the resize.
		*/
		static int setup_new_group_blocks(struct super_block *sb,
		struct ext4_new_group_data *input)
		{
		struct ext4_sb_info *sbi = EXT4_SB(sb);
		ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
		int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
		le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
		unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
		struct buffer_head *bh;
		handle_t *handle;
		ext4_fsblk_t block;
		ext4_grpblk_t bit;
		int i;
		int err = 0, err2;

		/* This transaction may be extended/restarted along the way */
		handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);

		if (IS_ERR(handle))
		return PTR_ERR(handle);

		BUG_ON(input->group != sbi->s_groups_count);

		/* Copy all of the GDT blocks into the backup in this group */
		for (i = 0, bit = 1, block = start + 1;
		i < gdblocks; i++, block++, bit++) {
		struct buffer_head *gdb;

		ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
		err = extend_or_restart_transaction(handle, 1);
		if (err)
		goto exit_journal;

		gdb = sb_getblk(sb, block);
		if (!gdb) {
		err = -EIO;
		goto exit_journal;
		}
		if ((err = ext4_journal_get_write_access(handle, gdb))) {
		brelse(gdb);
		goto exit_journal;
		}
		memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
		set_buffer_uptodate(gdb);
		err = ext4_handle_dirty_metadata(handle, NULL, gdb);
		if (unlikely(err)) {
		brelse(gdb);
		goto exit_journal;
		}
		brelse(gdb);
		}

		/* Zero out all of the reserved backup group descriptor table blocks */
		ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
		block, sbi->s_itb_per_group);
		err = sb_issue_zeroout(sb, gdblocks + start + 1, reserved_gdb,
		GFP_NOFS);
		if (err)
		goto exit_journal;

		err = extend_or_restart_transaction(handle, 2);
		if (err)
		goto exit_journal;

		bh = bclean(handle, sb, input->block_bitmap);
		if (IS_ERR(bh)) {
		err = PTR_ERR(bh);
		goto exit_journal;
		}

		if (ext4_bg_has_super(sb, input->group)) {
		ext4_debug("mark backup group tables %#04llx (+0)\n", start);
		ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb + 1);
		}

		ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap,
		input->block_bitmap - start);
		ext4_set_bit(input->block_bitmap - start, bh->b_data);
		ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap,
		input->inode_bitmap - start);
		ext4_set_bit(input->inode_bitmap - start, bh->b_data);

		/* Zero out all of the inode table blocks */
		block = input->inode_table;
		ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
		block, sbi->s_itb_per_group);
		err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, GFP_NOFS);
		if (err)
		goto exit_bh;
		ext4_set_bits(bh->b_data, input->inode_table - start,
		sbi->s_itb_per_group);


		ext4_mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8,
		bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (unlikely(err)) {
		ext4_std_error(sb, err);
		goto exit_bh;
		}
		brelse(bh);
		/* Mark unused entries in inode bitmap used */
		ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
		input->inode_bitmap, input->inode_bitmap - start);
		if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
		err = PTR_ERR(bh);
		goto exit_journal;
		}

		ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
		bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (unlikely(err))
		ext4_std_error(sb, err);
		exit_bh:
		brelse(bh);

		exit_journal:
		if ((err2 = ext4_journal_stop(handle)) && !err)
		err = err2;

		return err;
		}

		/*
		* Iterate through the groups which hold BACKUP superblock/GDT copies in an
		* ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
		@@ -1509,16 +1378,15 @@ static int ext4_setup_next_flex_gd(struct super_block *sb,
		*/
		int ext4_group_add(struct super_block sb, struct ext4_new_group_data input)
		{
		struct ext4_new_flex_group_data flex_gd;
		struct ext4_sb_info *sbi = EXT4_SB(sb);
		struct ext4_super_block *es = sbi->s_es;
		int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
		le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
		struct buffer_head *primary = NULL;
		struct ext4_group_desc *gdp;
		struct inode *inode = NULL;
		handle_t *handle;
		int gdb_off, gdb_num;
		int err, err2;
		int err;
		__u16 bg_flags = 0;

		gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
		gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
		@@ -1557,172 +1425,15 @@ int ext4_group_add(struct super_block sb, struct ext4_new_group_data input)
		}


		if ((err = verify_group_input(sb, input)))
		goto exit_put;

		if ((err = setup_new_group_blocks(sb, input)))
		goto exit_put;

		/*
		* We will always be modifying at least the superblock and a GDT
		* block. If we are adding a group past the last current GDT block,
		* we will also modify the inode and the dindirect block. If we
		* are adding a group with superblock/GDT backups we will also
		* modify each of the reserved GDT dindirect blocks.
		*/
		handle = ext4_journal_start_sb(sb,
		ext4_bg_has_super(sb, input->group) ?
		3 + reserved_gdb : 4);
		if (IS_ERR(handle)) {
		err = PTR_ERR(handle);
		goto exit_put;
		}

		if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
		goto exit_journal;

		/*
		* We will only either add reserved group blocks to a backup group
		* or remove reserved blocks for the first group in a new group block.
		* Doing both would be mean more complex code, and sane people don't
		* use non-sparse filesystems anymore. This is already checked above.
		*/
		if (gdb_off) {
		primary = sbi->s_group_desc[gdb_num];
		if ((err = ext4_journal_get_write_access(handle, primary)))
		goto exit_journal;

		if (reserved_gdb && ext4_bg_num_gdb(sb, input->group)) {
		err = reserve_backup_gdb(handle, inode, input->group);
		if (err)
		goto exit_journal;
		}
		} else {
		/*
		* Note that we can access new group descriptor block safely
		* only if add_new_gdb() succeeds.
		*/
		err = add_new_gdb(handle, inode, input->group);
		if (err)
		goto exit_journal;
		primary = sbi->s_group_desc[gdb_num];
		}

		/*
		* OK, now we've set up the new group. Time to make it active.
		*
		* so we have to be safe wrt. concurrent accesses the group
		* data. So we need to be careful to set all of the relevant
		* group descriptor data etc. before we enable the group.
		*
		* The key field here is sbi->s_groups_count: as long as
		* that retains its old value, nobody is going to access the new
		* group.
		*
		* So first we update all the descriptor metadata for the new
		* group; then we update the total disk blocks count; then we
		* update the groups count to enable the group; then finally we
		* update the free space counts so that the system can start
		* using the new disk blocks.
		*/

		/* Update group descriptor block for new group */
		gdp = (struct ext4_group_desc )((char )primary->b_data +
		gdb_off * EXT4_DESC_SIZE(sb));

		memset(gdp, 0, EXT4_DESC_SIZE(sb));
		ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
		ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
		ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
		ext4_free_group_clusters_set(sb, gdp, input->free_blocks_count);
		ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
		gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED);
		gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);

		/*
		* We can allocate memory for mb_alloc based on the new group
		* descriptor
		*/
		err = ext4_mb_add_groupinfo(sb, input->group, gdp);
		err = verify_group_input(sb, input);
		if (err)
		goto exit_journal;

		/*
		* Make the new blocks and inodes valid next. We do this before
		* increasing the group count so that once the group is enabled,
		* all of its blocks and inodes are already valid.
		*
		* We always allocate group-by-group, then block-by-block or
		* inode-by-inode within a group, so enabling these
		* blocks/inodes before the group is live won't actually let us
		* allocate the new space yet.
		*/
		ext4_blocks_count_set(es, ext4_blocks_count(es) +
		input->blocks_count);
		le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb));

		/*
		* We need to protect s_groups_count against other CPUs seeing
		* inconsistent state in the superblock.
		*
		* The precise rules we use are:
		*
		* * Writers must perform a smp_wmb() after updating all dependent
		* data and before modifying the groups count
		*
		* * Readers must perform an smp_rmb() after reading the groups count
		* and before reading any dependent data.
		*
		* NB. These rules can be relaxed when checking the group count
		* while freeing data, as we can only allocate from a block
		* group after serialising against the group count, and we can
		* only then free after serialising in turn against that
		* allocation.
		*/
		smp_wmb();

		/* Update the global fs size fields */
		sbi->s_groups_count++;

		err = ext4_handle_dirty_metadata(handle, NULL, primary);
		if (unlikely(err)) {
		ext4_std_error(sb, err);
		goto exit_journal;
		}

		/* Update the reserved block counts only once the new group is
		* active. */
		ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
		input->reserved_blocks);

		/* Update the free space counts */
		percpu_counter_add(&sbi->s_freeclusters_counter,
		EXT4_B2C(sbi, input->free_blocks_count));
		percpu_counter_add(&sbi->s_freeinodes_counter,
		EXT4_INODES_PER_GROUP(sb));

		if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
		sbi->s_log_groups_per_flex) {
		ext4_group_t flex_group;
		flex_group = ext4_flex_group(sbi, input->group);
		atomic_add(EXT4_B2C(sbi, input->free_blocks_count),
		&sbi->s_flex_groups[flex_group].free_clusters);
		atomic_add(EXT4_INODES_PER_GROUP(sb),
		&sbi->s_flex_groups[flex_group].free_inodes);
		}

		ext4_handle_dirty_super(handle, sb);
		goto out;

		exit_journal:
		if ((err2 = ext4_journal_stop(handle)) && !err)
		err = err2;
		if (!err && primary) {
		update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
		sizeof(struct ext4_super_block));
		update_backups(sb, primary->b_blocknr, primary->b_data,
		primary->b_size);
		}
		exit_put:
		flex_gd.count = 1;
		flex_gd.groups = input;
		flex_gd.bg_flags = &bg_flags;
		err = ext4_flex_group_add(sb, inode, &flex_gd);
		out:
		iput(inode);
		return err;
		} /* ext4_group_add */