Commit 84bc926c authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: check the largest extent at look-up time 



Because of the extent shrinker or other -ENOMEM scenarios, it cannot guarantee
that the largest extent would be cached in the tree all the time.

Instead of relying on extent_tree, we can simply check the cached one in extent
tree accordingly.

Reviewed-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 3e72f721

fs/f2fs/data.c

+14 −2
Original line number Diff line number Diff line
@@ -512,12 +512,22 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs, 
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	struct extent_tree *et = F2FS_I(inode)->extent_tree;

	struct extent_node *en;

	bool ret = false;



	f2fs_bug_on(sbi, !et);



	trace_f2fs_lookup_extent_tree_start(inode, pgofs);



	read_lock(&et->lock);



	if (et->largest.fofs <= pgofs &&

			et->largest.fofs + et->largest.len > pgofs) {

		*ei = et->largest;

		ret = true;

		stat_inc_read_hit(sbi->sb);

		goto out;

	}



	en = __lookup_extent_tree(et, pgofs);

	if (en) {

		*ei = en->ei;
@@ -526,13 +536,15 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs, 
			list_move_tail(&en->list, &sbi->extent_list);

		et->cached_en = en;

		spin_unlock(&sbi->extent_lock);

		ret = true;

		stat_inc_read_hit(sbi->sb);

	}

out:

	stat_inc_total_hit(sbi->sb);

	read_unlock(&et->lock);



	trace_f2fs_lookup_extent_tree_end(inode, pgofs, en);

	return en ? true : false;

	trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);

	return ret;

}



/* return true, if on-disk extent should be updated */

include/trace/events/f2fs.h

+6 −6
Original line number Diff line number Diff line
@@ -1099,11 +1099,11 @@ TRACE_EVENT(f2fs_lookup_extent_tree_start, 
TRACE_EVENT_CONDITION(f2fs_lookup_extent_tree_end,



	TP_PROTO(struct inode *inode, unsigned int pgofs,

						struct extent_node *en),

						struct extent_info *ei),



	TP_ARGS(inode, pgofs, en),

	TP_ARGS(inode, pgofs, ei),



	TP_CONDITION(en),

	TP_CONDITION(ei),



	TP_STRUCT__entry(

		__field(dev_t,	dev)
@@ -1118,9 +1118,9 @@ TRACE_EVENT_CONDITION(f2fs_lookup_extent_tree_end, 
		__entry->dev = inode->i_sb->s_dev;

		__entry->ino = inode->i_ino;

		__entry->pgofs = pgofs;

		__entry->fofs = en->ei.fofs;

		__entry->blk = en->ei.blk;

		__entry->len = en->ei.len;

		__entry->fofs = ei->fofs;

		__entry->blk = ei->blk;

		__entry->len = ei->len;

	),



	TP_printk("dev = (%d,%d), ino = %lu, pgofs = %u, "

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