[WIP] [PATCH 10/12] erofs-utils: fuse: cleanup erofs_read_data_compression()

[Gao Xiang]

[ let's fold in to the original patch. ]
Signed-off-by: Gao Xiang <hsiangkao at aol.com>
---
 fuse/read.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/fuse/read.c b/fuse/read.c
index 46be5cc64a90..f3aa628945e3 100644
--- a/fuse/read.c
+++ b/fuse/read.c
@@ -80,10 +80,10 @@ finished:
 }
 
 size_t erofs_read_data_compression(struct erofs_vnode *vnode, char *buffer,
-		       size_t size, off_t offset)
+				   erofs_off_t size, erofs_off_t offset)
 {
 	int ret;
-	size_t end, count, ofs, sum = size;
+	erofs_off_t end, length, skip;
 	struct erofs_map_blocks map = {
 		.index = UINT_MAX,
 	};
@@ -91,8 +91,8 @@ size_t erofs_read_data_compression(struct erofs_vnode *vnode, char *buffer,
 	unsigned int algorithmformat;
 	char raw[EROFS_BLKSIZ];
 
-	while (sum) {
-		end = offset + sum;
+	end = offset + size;
+	while (end > offset) {
 		map.m_la = end - 1;
 
 		ret = z_erofs_map_blocks_iter(vnode, &map);
@@ -100,7 +100,7 @@ size_t erofs_read_data_compression(struct erofs_vnode *vnode, char *buffer,
 			return ret;
 
 		if (!(map.m_flags & EROFS_MAP_MAPPED)) {
-			sum -= map.m_llen;
+			end = map.m_la;
 			continue;
 		}
 
@@ -117,28 +117,28 @@ size_t erofs_read_data_compression(struct erofs_vnode *vnode, char *buffer,
 		 * larger than requested, and set up partial flag as well.
 		 */
 		if (end < map.m_la + map.m_llen) {
-			count = end - map.m_la;
+			length = end - map.m_la;
 			partial = true;
 		} else {
 			ASSERT(end == map.m_la + map_m_llen);
-			count = map.m_llen;
+			length = map.m_llen;
 			partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED);
 		}
 
-		if ((off_t)map.m_la < offset) {
-			ofs = offset - map.m_la;
-			sum = 0;
+		if (map.m_la < offset) {
+			skip = offset - map.m_la;
+			end = offset;
 		} else {
-			ofs = 0;
-			sum -= count;
+			skip = 0;
+			end = map.m_la;
 		}
 
 		ret = z_erofs_decompress(&(struct z_erofs_decompress_req) {
 					.in = raw,
-					.out = buffer + sum,
-					.decodedskip = ofs,
-					.inputsize = EROFS_BLKSIZ,
-					.decodedlength = count,
+					.out = buffer + end - offset,
+					.decodedskip = skip,
+					.inputsize = map.m_plen,
+					.decodedlength = length,
 					.alg = algorithmformat,
 					.partial_decoding = partial
 					 });
-- 
2.24.0