ext4: factor out ext4_map_create_blocks() to allocate new blocks (1d7d5132) · Commits · EulixOS / Software / Kernel

fs/ext4/inode.c

+81 −76

Original line number	Diff line number	Diff line
		@@ -482,6 +482,86 @@ static int ext4_map_query_blocks(handle_t handle, struct inode inode,
		return retval;
		}

		static int ext4_map_create_blocks(handle_t handle, struct inode inode,
		struct ext4_map_blocks *map, int flags)
		{
		struct extent_status es;
		unsigned int status;
		int err, retval = 0;

		/*
		* Here we clear m_flags because after allocating an new extent,
		* it will be set again.
		*/
		map->m_flags &= ~EXT4_MAP_FLAGS;

		/*
		* We need to check for EXT4 here because migrate could have
		* changed the inode type in between.
		*/
		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
		retval = ext4_ext_map_blocks(handle, inode, map, flags);
		} else {
		retval = ext4_ind_map_blocks(handle, inode, map, flags);

		/*
		* We allocated new blocks which will result in i_data's
		* format changing. Force the migrate to fail by clearing
		* migrate flags.
		*/
		if (retval > 0 && map->m_flags & EXT4_MAP_NEW)
		ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
		}
		if (retval <= 0)
		return retval;

		if (unlikely(retval != map->m_len)) {
		ext4_warning(inode->i_sb,
		"ES len assertion failed for inode %lu: "
		"retval %d != map->m_len %d",
		inode->i_ino, retval, map->m_len);
		WARN_ON(1);
		}

		/*
		* We have to zeroout blocks before inserting them into extent
		* status tree. Otherwise someone could look them up there and
		* use them before they are really zeroed. We also have to
		* unmap metadata before zeroing as otherwise writeback can
		* overwrite zeros with stale data from block device.
		*/
		if (flags & EXT4_GET_BLOCKS_ZERO &&
		map->m_flags & EXT4_MAP_MAPPED && map->m_flags & EXT4_MAP_NEW) {
		err = ext4_issue_zeroout(inode, map->m_lblk, map->m_pblk,
		map->m_len);
		if (err)
		return err;
		}

		/*
		* If the extent has been zeroed out, we don't need to update
		* extent status tree.
		*/
		if (flags & EXT4_GET_BLOCKS_PRE_IO &&
		ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
		if (ext4_es_is_written(&es))
		return retval;
		}

		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
		EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
		!(status & EXTENT_STATUS_WRITTEN) &&
		ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
		map->m_lblk + map->m_len - 1))
		status \|= EXTENT_STATUS_DELAYED;

		ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
		map->m_pblk, status);

		return retval;
		}

		/*
		* The ext4_map_blocks() function tries to look up the requested blocks,
		* and returns if the blocks are already mapped.
		@@ -630,12 +710,6 @@ int ext4_map_blocks(handle_t handle, struct inode inode,
		if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
		return retval;

		/*
		* Here we clear m_flags because after allocating an new extent,
		* it will be set again.
		*/
		map->m_flags &= ~EXT4_MAP_FLAGS;

		/*
		* New blocks allocate and/or writing to unwritten extent
		* will possibly result in updating i_data, so we take
		@@ -643,76 +717,7 @@ int ext4_map_blocks(handle_t handle, struct inode inode,
		* with create == 1 flag.
		*/
		down_write(&EXT4_I(inode)->i_data_sem);

		/*
		* We need to check for EXT4 here because migrate
		* could have changed the inode type in between
		*/
		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
		retval = ext4_ext_map_blocks(handle, inode, map, flags);
		} else {
		retval = ext4_ind_map_blocks(handle, inode, map, flags);

		if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
		/*
		* We allocated new blocks which will result in
		* i_data's format changing. Force the migrate
		* to fail by clearing migrate flags
		*/
		ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
		}
		}

		if (retval > 0) {
		unsigned int status;

		if (unlikely(retval != map->m_len)) {
		ext4_warning(inode->i_sb,
		"ES len assertion failed for inode "
		"%lu: retval %d != map->m_len %d",
		inode->i_ino, retval, map->m_len);
		WARN_ON(1);
		}

		/*
		* We have to zeroout blocks before inserting them into extent
		* status tree. Otherwise someone could look them up there and
		* use them before they are really zeroed. We also have to
		* unmap metadata before zeroing as otherwise writeback can
		* overwrite zeros with stale data from block device.
		*/
		if (flags & EXT4_GET_BLOCKS_ZERO &&
		map->m_flags & EXT4_MAP_MAPPED &&
		map->m_flags & EXT4_MAP_NEW) {
		ret = ext4_issue_zeroout(inode, map->m_lblk,
		map->m_pblk, map->m_len);
		if (ret) {
		retval = ret;
		goto out_sem;
		}
		}

		/*
		* If the extent has been zeroed out, we don't need to update
		* extent status tree.
		*/
		if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
		ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
		if (ext4_es_is_written(&es))
		goto out_sem;
		}
		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
		EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
		!(status & EXTENT_STATUS_WRITTEN) &&
		ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
		map->m_lblk + map->m_len - 1))
		status \|= EXTENT_STATUS_DELAYED;
		ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
		map->m_pblk, status);
		}

		out_sem:
		retval = ext4_map_create_blocks(handle, inode, map, flags);
		up_write((&EXT4_I(inode)->i_data_sem));
		if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
		ret = check_block_validity(inode, map);