f2fs: add sysfs node to control ra_pages for fadvise seq file
fadvise() allows the user to expand the readahead window to double with
POSIX_FADV_SEQUENTIAL, now. But, in some use cases, it is not that
sufficient and we need to meet the need in a restricted way. We can
control the multiplier value of bdi device readahead between 2 (default)
and 256 for POSIX_FADV_SEQUENTIAL advise option.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index a4fed18..84cd085 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3466,6 +3466,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
sbi->migration_granularity = sbi->segs_per_sec;
+ sbi->seq_file_ra_mul = MIN_RA_MUL;
sbi->dir_level = DEF_DIR_LEVEL;
sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;