[PATCH v2] erofs-utils: fsck: extract chunk-based file with hole correctly

[Yifan Zhao]

Currently fsck skips file extraction if it finds that EROFS_MAP_MAPPED
is unset, which is not the case for chunk-based files with hole. This
patch handles the corner case correctly.

Signed-off-by: Yifan Zhao <zhaoyifan at sjtu.edu.cn>
---
changelog since v1:
- use lseek instead of write zero to the hole

 fsck/main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fsck/main.c b/fsck/main.c
index e5c37be..249ccd4 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -470,7 +470,7 @@ static int erofs_verify_inode_data(struct erofs_inode *inode, int outfd)
 		pos += map.m_llen;
 
 		/* should skip decomp? */
-		if (!(map.m_flags & EROFS_MAP_MAPPED) || !fsckcfg.check_decomp)
+		if (map.m_la >= inode->i_size || !fsckcfg.check_decomp)
 			continue;
 
 		if (map.m_plen > Z_EROFS_PCLUSTER_MAX_SIZE) {
@@ -513,6 +513,15 @@ static int erofs_verify_inode_data(struct erofs_inode *inode, int outfd)
 		} else {
 			u64 p = 0;
 
+			if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+				ret = lseek(outfd, map.m_llen, SEEK_CUR);
+				if (ret < 0) {
+					ret = -errno;
+					goto out;
+				}
+				continue;
+			}
+
 			do {
 				u64 count = min_t(u64, alloc_rawsize,
 						  map.m_llen);
-- 
2.44.0