From 9a9aecaad92d4fba0e2682ca6897d3a5aeabf123 Mon Sep 17 00:00:00 2001 From: Daniel Rosenberg Date: Wed, 29 May 2019 17:49:04 -0700 Subject: [PATCH] f2fs: Fix root reserved on remount On a remount, you can currently set root reserved if it was not previously set. This can cause an underflow if reserved has been set to a very high value, since then root reserved + current reserved could be greater than user_block_count. inc_valid_block_count later subtracts out these values from user_block_count, causing an underflow. Signed-off-by: Daniel Rosenberg Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 1dc02101e5e5..4b547024571f 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -213,7 +213,8 @@ void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...) static inline void limit_reserve_root(struct f2fs_sb_info *sbi) { - block_t limit = (sbi->user_block_count << 1) / 1000; + block_t limit = min((sbi->user_block_count << 1) / 1000, + sbi->user_block_count - sbi->reserved_blocks); /* limit is 0.2% */ if (test_opt(sbi, RESERVE_ROOT) &&