nilfs2: add btree get block function with readahead option (464ece88) · Commits · 戴 / test

fs/nilfs2/btree.c

+68 −26

Original line number	Diff line number	Diff line
		@@ -66,32 +66,6 @@ static void nilfs_btree_free_path(struct nilfs_btree_path *path)
		/*
		* B-tree node operations
		*/
		static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
		struct buffer_head **bhp)
		{
		struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
		struct buffer_head *bh;
		sector_t pbn = 0;
		int err;

		err = nilfs_btnode_submit_block(btnc, ptr, pbn, READ, bhp, &pbn);
		if (err)
		return err == -EEXIST ? 0 : err;

		bh = *bhp;
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
		brelse(bh);
		return -EIO;
		}
		if (nilfs_btree_broken_node_block(bh)) {
		clear_buffer_uptodate(bh);
		brelse(bh);
		return -EINVAL;
		}
		return 0;
		}

		static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree,
		__u64 ptr, struct buffer_head **bhp)
		{
		@@ -452,6 +426,74 @@ nilfs_btree_bad_node(struct nilfs_btree_node *node, int level)
		return 0;
		}

		struct nilfs_btree_readahead_info {
		struct nilfs_btree_node node; / parent node */
		int max_ra_blocks; /* max nof blocks to read ahead */
		int index; /* current index on the parent node */
		int ncmax; /* nof children in the parent node */
		};

		static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
		struct buffer_head **bhp,
		const struct nilfs_btree_readahead_info *ra)
		{
		struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
		struct buffer_head bh, ra_bh;
		sector_t submit_ptr = 0;
		int ret;

		ret = nilfs_btnode_submit_block(btnc, ptr, 0, READ, &bh, &submit_ptr);
		if (ret) {
		if (ret != -EEXIST)
		return ret;
		goto out_check;
		}

		if (ra) {
		int i, n;
		__u64 ptr2;

		/* read ahead sibling nodes */
		for (n = ra->max_ra_blocks, i = ra->index + 1;
		n > 0 && i < ra->ncmax; n--, i++) {
		ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax);

		ret = nilfs_btnode_submit_block(btnc, ptr2, 0, READA,
		&ra_bh, &submit_ptr);
		if (likely(!ret \|\| ret == -EEXIST))
		brelse(ra_bh);
		else if (ret != -EBUSY)
		break;
		if (!buffer_locked(bh))
		goto out_no_wait;
		}
		}

		wait_on_buffer(bh);

		out_no_wait:
		if (!buffer_uptodate(bh)) {
		brelse(bh);
		return -EIO;
		}

		out_check:
		if (nilfs_btree_broken_node_block(bh)) {
		clear_buffer_uptodate(bh);
		brelse(bh);
		return -EINVAL;
		}

		*bhp = bh;
		return 0;
		}

		static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
		struct buffer_head **bhp)
		{
		return __nilfs_btree_get_block(btree, ptr, bhp, NULL);
		}

		static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree,
		struct nilfs_btree_path *path,
		__u64 key, __u64 *ptrp, int minlevel)

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