[PATCH v2 2/4] erofs-utils: lib: fix large chunk index writes

[Yifan Zhao <stopire@gmail.com>]

Use ssize_t for chunk index write results in erofs_write_chunk_indexes()
and erofs_iflush().  Widen index buffer offsets and inode metadata size
calculations to avoid truncation with large index tables.

Assisted-by: Codex:gpt-6-astra
Signed-off-by: Yifan Zhao <stopire@gmail.com>
---
 lib/blobchunk.c      |  7 ++++---
 lib/inode.c          | 19 +++++++++----------
 lib/liberofs_chunk.h |  4 ++--
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/lib/blobchunk.c b/lib/blobchunk.c
index 8f43dd0..2f42541 100644
--- a/lib/blobchunk.c
+++ b/lib/blobchunk.c
@@ -192,8 +192,8 @@ void erofs_inode_fixup_chunkformat(struct erofs_inode *inode)
 		inode->u.chunkformat |= EROFS_CHUNK_FORMAT_48BIT;
 }
 
-int erofs_write_chunk_indexes(struct erofs_inode *inode, struct erofs_vfile *vf,
-			      erofs_off_t off)
+ssize_t erofs_write_chunk_indexes(struct erofs_inode *inode, struct erofs_vfile *vf,
+				 erofs_off_t off)
 {
 	struct erofs_sb_info *sbi = inode->sbi;
 	erofs_blk_t remaining_blks = BLK_ROUND_UP(sbi, inode->i_size);
@@ -201,7 +201,8 @@ int erofs_write_chunk_indexes(struct erofs_inode *inode, struct erofs_vfile *vf,
 	erofs_blk_t extent_end = EROFS_NULL_ADDR, chunkblks, addrmask;
 	erofs_blk_t extent_start = EROFS_NULL_ADDR;
 	erofs_off_t source_offset;
-	unsigned int dst, src, unit, zeroedlen;
+	unsigned int unit, zeroedlen;
+	size_t dst, src;
 	bool _48bit;
 
 	if (inode->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
diff --git a/lib/inode.c b/lib/inode.c
index ec96556..0cf09b8 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -816,7 +816,8 @@ int erofs_iflush(struct erofs_inode *inode)
 	struct iovec iov[2];
 	char *xattrs = NULL;
 	bool nlink_1 = true;
-	int ret, fmt;
+	ssize_t ret;
+	int fmt;
 
 	DBG_BUGON(inode->nid == EROFS_NID_UNALLOCATED);
 	DBG_BUGON(bh && erofs_btell(bh, false) != off);
@@ -998,11 +999,11 @@ static bool erofs_inode_need_48bit(struct erofs_inode *inode)
 	return false;
 }
 
-static unsigned int erofs_inode_meta_size(struct erofs_inode *inode)
+static erofs_off_t erofs_inode_meta_size(struct erofs_inode *inode)
 {
-	unsigned int inodesize;
+	erofs_off_t inodesize;
 
-	inodesize = inode->inode_isize + inode->xattr_isize;
+	inodesize = inode->inode_isize + (erofs_off_t)inode->xattr_isize;
 	if (inode->extent_isize)
 		inodesize = roundup(inodesize, 8) + inode->extent_isize;
 	return inodesize;
@@ -1014,7 +1015,7 @@ static int erofs_prepare_inode_buffer(struct erofs_importer *im,
 	const struct erofs_importer_params *params = im->params;
 	struct erofs_sb_info *sbi = im->sbi;
 	struct erofs_bufmgr *ibmgr;
-	unsigned int inodesize;
+	erofs_off_t inodesize;
 	struct erofs_buffer_head *bh, *ibh;
 
 	DBG_BUGON(inode->bh || inode->bh_inline);
@@ -2456,7 +2457,8 @@ int erofs_fixup_root_inode(struct erofs_inode *root)
 {
 	struct erofs_sb_info *sbi = root->sbi;
 	struct erofs_inode oi;
-	unsigned int ondisk_capacity, ondisk_size;
+	unsigned int ondisk_capacity;
+	erofs_off_t ondisk_size;
 	char *ibuf;
 	int err;
 
@@ -2484,10 +2486,7 @@ int erofs_fixup_root_inode(struct erofs_inode *root)
 	if (oi.datalayout == EROFS_INODE_FLAT_INLINE)
 		ondisk_capacity += erofs_blkoff(sbi, oi.i_size);
 
-	ondisk_size = root->inode_isize + root->xattr_isize;
-	if (root->extent_isize)
-		ondisk_size = roundup(ondisk_size, 8) + root->extent_isize;
-	ondisk_size += root->idata_size;
+	ondisk_size = erofs_inode_meta_size(root) + root->idata_size;
 
 	if (ondisk_size > ondisk_capacity) {
 		erofs_err("no enough room for the root inode from nid %llu",
diff --git a/lib/liberofs_chunk.h b/lib/liberofs_chunk.h
index 16f3d05..64e7ec8 100644
--- a/lib/liberofs_chunk.h
+++ b/lib/liberofs_chunk.h
@@ -18,8 +18,8 @@ struct erofs_chunkitem *erofs_get_unhashed_chunk(struct erofs_sb_info *sbi,
 		unsigned int device_id, erofs_blk_t blkaddr,
 		erofs_off_t sourceoffset);
 void erofs_inode_fixup_chunkformat(struct erofs_inode *inode);
-int erofs_write_chunk_indexes(struct erofs_inode *inode, struct erofs_vfile *vf,
-			      erofs_off_t off);
+ssize_t erofs_write_chunk_indexes(struct erofs_inode *inode, struct erofs_vfile *vf,
+				 erofs_off_t off);
 int erofs_blob_write_chunked_file(struct erofs_inode *inode, int fd,
 				  erofs_off_t startoff, int device_id);
 int erofs_write_zero_inode(struct erofs_inode *inode);
-- 
2.55.0