In ->get_victim we get max_search value from dirty_i->nr_dirty without protection of seglist_lock, after that, nr_dirty can be increased/decreased before we hold seglist_lock lock. Then in main loop we attempt to traverse all dirty section one time to find victim section, but it's not accurate to use max_search as the total loop count, because we might lose checking several sections or check sections redundantly for the case of nr_dirty are increased or decreased previously.
Signed-off-by: Chao Yu <[email protected]> --- fs/f2fs/gc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 075ea1e..4481edc 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -263,14 +263,14 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, unsigned int secno, max_cost; int nsearched = 0; + mutex_lock(&dirty_i->seglist_lock); + p.alloc_mode = alloc_mode; select_policy(sbi, gc_type, type, &p); p.min_segno = NULL_SEGNO; p.min_cost = max_cost = get_max_cost(sbi, &p); - mutex_lock(&dirty_i->seglist_lock); - if (p.alloc_mode == LFS && gc_type == FG_GC) { p.min_segno = check_bg_victims(sbi); if (p.min_segno != NULL_SEGNO) -- 2.0.1.474.g72c7794 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
