f2fs: fix to access nullified flush_cmd_control pointer
f2fs_sync_file() remount_ro
- f2fs_readonly
- destroy_flush_cmd_control
- f2fs_issue_flush
- no fcc pointer!
So, this patch doesn't free fcc in this case, but just stop its kernel thread
which sends flush commands.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 1a52647..b62c10d 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1102,8 +1102,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
* or if flush_merge is not passed in mount option.
*/
if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
- destroy_flush_cmd_control(sbi);
- } else if (!SM_I(sbi)->cmd_control_info) {
+ clear_opt(sbi, FLUSH_MERGE);
+ destroy_flush_cmd_control(sbi, false);
+ } else {
err = create_flush_cmd_control(sbi);
if (err)
goto restore_gc;
