vvfat: Fix usage of `info.file.offset`

The field is marked as "the offset in the file (in clusters)", but it
was being used like this
`cluster_size*(nums)+mapping->info.file.offset`, which is incorrect.

Signed-off-by: Amjad Alsharafi <amjadsharafi10@gmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <72f19a7903886dda1aa78bcae0e17702ee939262.1721470238.git.amjadsharafi10@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block/vvfat.c b/block/vvfat.c
index a67cfa823bcaf267d07ca4d7b28221e51ebea083..cfde468c2ef60dba9a7761e4292d87005153e1ee 100644 (file)
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1408,7 +1408,9 @@ read_cluster_directory:
 
         assert(s->current_fd);
 
-        offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
+        offset = s->cluster_size *
+            ((cluster_num - s->current_mapping->begin)
+            + s->current_mapping->info.file.offset);
         if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
             return -3;
         s->cluster=s->cluster_buffer;
@@ -1929,8 +1931,9 @@ get_cluster_count_for_direntry(BDRVVVFATState* s, direntry_t* direntry, const ch
                         (mapping->mode & MODE_DIRECTORY) == 0) {
 
                     /* was modified in qcow */
-                    if (offset != mapping->info.file.offset + s->cluster_size
-                            * (cluster_num - mapping->begin)) {
+                    if (offset != s->cluster_size
+                            * ((cluster_num - mapping->begin)
+                            + mapping->info.file.offset)) {
                         /* offset of this cluster in file chain has changed */
                         abort();
                         copy_it = 1;
@@ -2404,7 +2407,7 @@ static int commit_mappings(BDRVVVFATState* s,
                         (mapping->end - mapping->begin);
             } else
                 next_mapping->info.file.offset = mapping->info.file.offset +
-                        mapping->end - mapping->begin;
+                        (mapping->end - mapping->begin);
 
             mapping = next_mapping;
         }