f2fs: indicate shutdown f2fs to allow unmount successfully

Once we shutdown f2fs, we have to flush stale pages in order to unmount
the system. In order to make stable, we need to stop fault injection as well.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/checkpoint.c

@@ -28,6 +28,7 @@ struct kmem_cache *f2fs_inode_entry_slab;
 
 void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
 {
+	f2fs_build_fault_attr(sbi, 0);
 	set_ckpt_flags(sbi, CP_ERROR_FLAG);
 	if (!end_io)
 		f2fs_flush_merged_writes(sbi);

fs/f2fs/f2fs.h

@@ -1066,6 +1066,7 @@ enum {
 	SBI_POR_DOING,				/* recovery is doing or not */
 	SBI_NEED_SB_WRITE,			/* need to recover superblock */
 	SBI_NEED_CP,				/* need to checkpoint */
+	SBI_IS_SHUTDOWN,			/* shutdown by ioctl */
 };
 
 enum {
@@ -3373,4 +3374,10 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)
 			F2FS_I_SB(inode)->s_ndevs);
 }
 
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+extern void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate);
+#else
+#define f2fs_build_fault_attr(sbi, rate)		do { } while (0)
+#endif
+
 #endif

fs/f2fs/file.c

@@ -1889,6 +1889,7 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
 		}
 		if (sb) {
 			f2fs_stop_checkpoint(sbi, false);
+			set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
 			thaw_bdev(sb->s_bdev, sb);
 		}
 		break;
@@ -1898,13 +1899,16 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
 		if (ret)
 			goto out;
 		f2fs_stop_checkpoint(sbi, false);
+		set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
 		break;
 	case F2FS_GOING_DOWN_NOSYNC:
 		f2fs_stop_checkpoint(sbi, false);
+		set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
 		break;
 	case F2FS_GOING_DOWN_METAFLUSH:
 		f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_META_IO);
 		f2fs_stop_checkpoint(sbi, false);
+		set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
 		break;
 	default:
 		ret = -EINVAL;

fs/f2fs/inode.c

@@ -159,6 +159,9 @@ bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page)
 	struct f2fs_inode *ri;
 	__u32 provided, calculated;
 
+	if (unlikely(is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN)))
+		return true;
+
 	if (!f2fs_enable_inode_chksum(sbi, page) ||
 			PageDirty(page) || PageWriteback(page))
 		return true;

fs/f2fs/node.c

@@ -1146,7 +1146,8 @@ static int read_node_page(struct page *page, int op_flags)
 
 	f2fs_get_node_info(sbi, page->index, &ni);
 
-	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+	if (unlikely(ni.blk_addr == NULL_ADDR) ||
+			is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN)) {
 		ClearPageUptodate(page);
 		return -ENOENT;
 	}

fs/f2fs/super.c

@@ -57,8 +57,7 @@ char *fault_name[FAULT_MAX] = {
 	[FAULT_CHECKPOINT]	= "checkpoint error",
 };
 
-static void f2fs_build_fault_attr(struct f2fs_sb_info *sbi,
-						unsigned int rate)
+void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate)
 {
 	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
 
@@ -1379,9 +1378,7 @@ static void default_options(struct f2fs_sb_info *sbi)
 	set_opt(sbi, POSIX_ACL);
 #endif
 
-#ifdef CONFIG_F2FS_FAULT_INJECTION
 	f2fs_build_fault_attr(sbi, 0);
-#endif
 }
 
 #ifdef CONFIG_QUOTA