[PATCH 1/2] erofs-utils: fix missing tail blocks for directories

[Gao Xiang]

Currently directory blocks will be allocated after inode metadata
space is reserved, but miss to fix tail blocks.

Fixes: 21d84349e79a ("erofs-utils: rearrange on-disk metadata")
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
 include/erofs/internal.h |  1 +
 lib/inode.c              | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 1f1e730..641a795 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -180,6 +180,7 @@ struct erofs_inode {
 	/* inline tail-end packing size */
 	unsigned short idata_size;
 	bool compressed_idata;
+	bool lazy_tailblock;
 
 	unsigned int xattr_isize;
 	unsigned int extent_isize;
diff --git a/lib/inode.c b/lib/inode.c
index 9db84a8..871968d 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -608,7 +608,12 @@ static int erofs_prepare_tail_block(struct erofs_inode *inode)
 	if (bh) {
 		/* expend a block as the tail block (should be successful) */
 		ret = erofs_bh_balloon(bh, erofs_blksiz());
-		DBG_BUGON(ret != erofs_blksiz());
+		if (ret != erofs_blksiz()) {
+			DBG_BUGON(1);
+			return -EIO;
+		}
+	} else {
+		inode->lazy_tailblock = true;
 	}
 	return 0;
 }
@@ -743,6 +748,15 @@ static int erofs_write_tail_end(struct erofs_inode *inode)
 			inode->u.i_blkaddr = bh->block->blkaddr;
 			inode->bh_data = bh;
 		} else {
+			if (inode->lazy_tailblock) {
+				/* expend a tail block (should be successful) */
+				ret = erofs_bh_balloon(bh, erofs_blksiz());
+				if (ret != erofs_blksiz()) {
+					DBG_BUGON(1);
+					return -EIO;
+				}
+				inode->lazy_tailblock = false;
+			}
 			ret = erofs_mapbh(bh->block);
 		}
 		DBG_BUGON(ret < 0);
-- 
2.24.4