ext4: refactor code to read the extent tree block (7d7ea89e) · Commits · 戴 / test

fs/ext4/extents.c

+43 −54

Original line number	Diff line number	Diff line
		@@ -464,25 +464,39 @@ int ext4_ext_check_inode(struct inode *inode)
		return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
		}

		static int __ext4_ext_check_block(const char *function, unsigned int line,
		struct inode *inode,
		struct ext4_extent_header *eh,
		int depth,
		struct buffer_head *bh)
		static struct buffer_head *
		__read_extent_tree_block(const char *function, unsigned int line,
		struct inode *inode, ext4_fsblk_t pblk, int depth)
		{
		int ret;
		struct buffer_head *bh;
		int err;

		bh = sb_getblk(inode->i_sb, pblk);
		if (unlikely(!bh))
		return ERR_PTR(-ENOMEM);

		if (!bh_uptodate_or_lock(bh)) {
		trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
		err = bh_submit_read(bh);
		if (err < 0)
		goto errout;
		}
		if (buffer_verified(bh))
		return 0;
		ret = ext4_ext_check(inode, eh, depth);
		if (ret)
		return ret;
		return bh;
		err = __ext4_ext_check(function, line, inode,
		ext_block_hdr(bh), depth);
		if (err)
		goto errout;
		set_buffer_verified(bh);
		return ret;
		return bh;
		errout:
		put_bh(bh);
		return ERR_PTR(err);

		}

		#define ext4_ext_check_block(inode, eh, depth, bh) \
		__ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
		#define read_extent_tree_block(inode, pblk, depth) \
		__read_extent_tree_block(__func__, __LINE__, (inode), (pblk), (depth))

		#ifdef EXT_DEBUG
		static void ext4_ext_show_path(struct inode inode, struct ext4_ext_path path)
		@@ -748,20 +762,12 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
		path[ppos].p_depth = i;
		path[ppos].p_ext = NULL;

		bh = sb_getblk(inode->i_sb, path[ppos].p_block);
		if (unlikely(!bh)) {
		ret = -ENOMEM;
		goto err;
		}
		if (!bh_uptodate_or_lock(bh)) {
		trace_ext4_ext_load_extent(inode, block,
		path[ppos].p_block);
		ret = bh_submit_read(bh);
		if (ret < 0) {
		put_bh(bh);
		bh = read_extent_tree_block(inode, path[ppos].p_block, --i);
		if (IS_ERR(bh)) {
		ret = PTR_ERR(bh);
		goto err;
		}
		}

		eh = ext_block_hdr(bh);
		ppos++;
		if (unlikely(ppos > depth)) {
		@@ -773,11 +779,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
		}
		path[ppos].p_bh = bh;
		path[ppos].p_hdr = eh;
		i--;

		ret = ext4_ext_check_block(inode, eh, i, bh);
		if (ret < 0)
		goto err;
		}

		path[ppos].p_depth = i;
		@@ -1412,29 +1413,21 @@ got_index:
		ix++;
		block = ext4_idx_pblock(ix);
		while (++depth < path->p_depth) {
		bh = sb_bread(inode->i_sb, block);
		if (bh == NULL)
		return -EIO;
		eh = ext_block_hdr(bh);
		/* subtract from p_depth to get proper eh_depth */
		if (ext4_ext_check_block(inode, eh,
		path->p_depth - depth, bh)) {
		put_bh(bh);
		return -EIO;
		}
		bh = read_extent_tree_block(inode, block,
		path->p_depth - depth);
		if (IS_ERR(bh))
		return PTR_ERR(bh);
		eh = ext_block_hdr(bh);
		ix = EXT_FIRST_INDEX(eh);
		block = ext4_idx_pblock(ix);
		put_bh(bh);
		}

		bh = sb_bread(inode->i_sb, block);
		if (bh == NULL)
		return -EIO;
		bh = read_extent_tree_block(inode, block, path->p_depth - depth);
		if (IS_ERR(bh))
		return PTR_ERR(bh);
		eh = ext_block_hdr(bh);
		if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
		put_bh(bh);
		return -EIO;
		}
		ex = EXT_FIRST_EXTENT(eh);
		found_extent:
		*logical = le32_to_cpu(ex->ee_block);
		@@ -2829,10 +2822,11 @@ again:
		ext_debug("move to level %d (block %llu)\n",
		i + 1, ext4_idx_pblock(path[i].p_idx));
		memset(path + i + 1, 0, sizeof(*path));
		bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
		if (!bh) {
		bh = read_extent_tree_block(inode,
		ext4_idx_pblock(path[i].p_idx), depth - i - 1);
		if (IS_ERR(bh)) {
		/* should we reset i_size? */
		err = -EIO;
		err = PTR_ERR(bh);
		break;
		}
		/* Yield here to deal with large extent trees.
		@@ -2842,11 +2836,6 @@ again:
		err = -EIO;
		break;
		}
		if (ext4_ext_check_block(inode, ext_block_hdr(bh),
		depth - i - 1, bh)) {
		err = -EIO;
		break;
		}
		path[i + 1].p_bh = bh;

		/* save actual number of indexes since this

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