f2fs: retry to update the inode page given data corruption

If the storage gives a corrupted node block due to short power failure and
reset, f2fs stops the entire operations by setting the checkpoint failure flag.

Let's give more chances to live by re-issuing IOs for a while in such critical
path.

Cc: stable@vger.kernel.org
Suggested-by: Randall Huang <huangrandall@google.com>
Suggested-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/inode.c

@@ -724,18 +724,19 @@ void f2fs_update_inode_page(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct page *node_page;
+	int count = 0;
 retry:
 	node_page = f2fs_get_node_page(sbi, inode->i_ino);
 	if (IS_ERR(node_page)) {
 		int err = PTR_ERR(node_page);
 
-		if (err == -ENOMEM) {
-			cond_resched();
+		/* The node block was truncated. */
+		if (err == -ENOENT)
+			return;
+
+		if (err == -ENOMEM || ++count <= DEFAULT_RETRY_IO_COUNT)
 			goto retry;
-		} else if (err != -ENOENT) {
-			f2fs_stop_checkpoint(sbi, false,
-					STOP_CP_REASON_UPDATE_INODE);
-		}
+		f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_UPDATE_INODE);
 		return;
 	}
 	f2fs_update_inode(inode, node_page);