f2fs: relax sanity check if checkpoint is corrupted

1. extent_cache
 - let's drop the largest extent_cache
2. invalidate_block
 - don't show the warnings

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/checkpoint.c

@@ -152,6 +152,11 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
 	se = get_seg_entry(sbi, segno);
 
 	exist = f2fs_test_bit(offset, se->cur_valid_map);
+
+	/* skip data, if we already have an error in checkpoint. */
+	if (unlikely(f2fs_cp_error(sbi)))
+		return exist;
+
 	if (exist && type == DATA_GENERIC_ENHANCE_UPDATE) {
 		f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
 			 blkaddr, exist);
@@ -202,6 +207,11 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
 	case DATA_GENERIC_ENHANCE_UPDATE:
 		if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
 				blkaddr < MAIN_BLKADDR(sbi))) {
+
+			/* Skip to emit an error message. */
+			if (unlikely(f2fs_cp_error(sbi)))
+				return false;
+
 			f2fs_warn(sbi, "access invalid blkaddr:%u",
 				  blkaddr);
 			set_sbi_flag(sbi, SBI_NEED_FSCK);

fs/f2fs/data.c

@@ -2237,6 +2237,10 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 	if (ret)
 		goto out;
 
+	if (unlikely(f2fs_cp_error(sbi))) {
+		ret = -EIO;
+		goto out_put_dnode;
+	}
 	f2fs_bug_on(sbi, dn.data_blkaddr != COMPRESS_ADDR);
 
 skip_reading_dnode:

fs/f2fs/extent_cache.c

@@ -23,18 +23,26 @@ bool sanity_check_extent_cache(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct extent_tree *et = fi->extent_tree[EX_READ];
 	struct extent_info *ei;
 
-	if (!fi->extent_tree[EX_READ])
+	if (!et)
 		return true;
 
-	ei = &fi->extent_tree[EX_READ]->largest;
+	ei = &et->largest;
+	if (!ei->len)
+		return true;
 
-	if (ei->len &&
-		(!f2fs_is_valid_blkaddr(sbi, ei->blk,
-					DATA_GENERIC_ENHANCE) ||
-		!f2fs_is_valid_blkaddr(sbi, ei->blk + ei->len - 1,
-					DATA_GENERIC_ENHANCE))) {
+	/* Let's drop, if checkpoint got corrupted. */
+	if (is_set_ckpt_flags(sbi, CP_ERROR_FLAG)) {
+		ei->len = 0;
+		et->largest_updated = true;
+		return true;
+	}
+
+	if (!f2fs_is_valid_blkaddr(sbi, ei->blk, DATA_GENERIC_ENHANCE) ||
+	    !f2fs_is_valid_blkaddr(sbi, ei->blk + ei->len - 1,
+					DATA_GENERIC_ENHANCE)) {
 		set_sbi_flag(sbi, SBI_NEED_FSCK);
 		f2fs_warn(sbi, "%s: inode (ino=%lx) extent info [%u, %u, %u] is incorrect, run fsck to fix",
 			  __func__, inode->i_ino,