Avoid mixing cluster numbers and sector numbers. Makes code more readable.

Obtained from:	NetBSD
MFC after:	2 weeks

1 files changed, 7 insertions, 5 deletions

diff --git a/sbin/fsck_msdosfs/dir.c b/sbin/fsck_msdosfs/dir.c
index 2163db049fac..7e459c75d4ff 100644
--- a/sbin/fsck_msdosfs/dir.c
+++ b/sbin/fsck_msdosfs/dir.c
@@ -317,7 +317,8 @@ delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
 				break;
 			e = delbuf + endoff;
 		}
-		off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
+		off = (startcl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
+
 		off *= boot->bpbBytesPerSec;
 		if (lseek(f, off, SEEK_SET) != off) {
 			perr("Unable to lseek to %" PRId64, off);
@@ -457,7 +458,7 @@ check_subdirectory(int f, struct bootblock *boot, struct dosDirEntry *dir)
 		off = boot->bpbResSectors + boot->bpbFATs *
 			boot->FATsecs;
 	} else {
-		off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
+		off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
 	}
 
 	/*
@@ -538,7 +539,7 @@ readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
 			    boot->FATsecs;
 		} else {
 			last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
-			off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
+			off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
 		}
 
 		off *= boot->bpbBytesPerSec;
@@ -1069,8 +1070,9 @@ reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
 			lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0;
 			return FSERROR;
 		}
-		lfoff = lfcl * boot->ClusterSize
-		    + boot->ClusterOffset * boot->bpbBytesPerSec;
+		lfoff = (lfcl - CLUST_FIRST) * boot->ClusterSize
+		    + boot->FirstCluster * boot->bpbBytesPerSec;
+
 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
 		    || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
 			perr("could not read LOST.DIR");