.

bigfile/tests/test_virtmem.c

@@ -1125,6 +1125,7 @@ struct BigFileMMap {
     BigFile;
     int fd;         /* fd of file to mmap */
     int nstoreblk;  /* number of times storeblk called */
+    int nmunmap;    /* ----//----      munmap   called */
 };
 typedef struct BigFileMMap BigFileMMap;
 
@@ -1184,11 +1185,20 @@ int mmapfile_remmap_blk_read(BigFile *file, blk_t blk, VMA *vma) {
     return 0;
 }
 
+void mmapfile_munmap(BigFile *file, VMA *vma) {
+    BigFileMMap *f = upcast(BigFileMMap*, file);
+    size_t len = vma->addr_stop - vma->addr_start;
+
+    f->nmunmap++;
+    xmunmap((void *)vma->addr_start, len);
+}
+
 static const struct bigfile_ops mmapfile_ops = {
     .loadblk            = NULL,
+    .storeblk           = mmapfile_storeblk,
     .mmap_setup_read    = mmapfile_mmap_setup_read,
     .remmap_blk_read    = mmapfile_remmap_blk_read,
-    .storeblk           = mmapfile_storeblk,
+    .munmap             = mmapfile_munmap,
     .release            = mmapfile_release,
 };
 
@@ -1233,6 +1243,7 @@ void test_file_access_mmapbase(void)
         .file_ops   = &mmapfile_ops,
         .fd         = fd,
         .nstoreblk  = 0,
+        .nmunmap    = 0,
     };
 
     /* fstore stores data into file[blk] */
@@ -1609,7 +1620,10 @@ void test_file_access_mmapbase(void)
 
 
     /* free resources */
+    file.nmunmap = 0;
     vma_unmap(vma);
+    ok1(file.nmunmap == 1);
+
     fileh_close(fh);
     ram_close(ram);
     free(ram);

bigfile/virtmem.c

@@ -322,8 +322,11 @@ void vma_unmap(VMA *vma)
 
     /* unmap whole vma at once - the kernel unmaps each mapping in turn.
      * NOTE error here would mean something is broken */
-    // XXX overlay: -> notify_unmap
+    if (fileh->mmap_overlay) {
+        fileh->file->file_ops->munmap(fileh->file, vma);
+    } else {
         xmunmap((void *)vma->addr_start, len);
+    }
 
     /* scan through mapped-to-this-vma pages and release them */
     for (i=0; i < pglen; ++i) {

include/wendelin/bigfile/file.h

@@ -102,6 +102,13 @@ struct bigfile_ops {
     // XXX error -> bug (must not fail)
     int (*remmap_blk_read) (BigFile *file, blk_t, VMA *vma);
 
+    /* munmap is called when vma set up via mmap_setup_read is going to be unmapped.
+     *
+     * XXX called under virtmem lock?
+     * Must not fail.
+     */
+    void (*munmap) (BigFile *file, VMA *vma);
+