.

wcfs/internal/wcfs_virtmem.cpp

@@ -60,6 +60,7 @@ const Tid TidHead = -1ULL;
 static string h(uint64_t v); // v -> 016x hex representation
 #define h_(v)   (h(v).c_str())
 static error mmap_zero_into_ro(void *addr, size_t size);
+static error mmap_into_ro(void *addr, size_t size, const os::File &f, off_t offset);
 
 // XXX ok?
 struct IContext {
@@ -423,7 +424,7 @@ error Conn::resync(Tid at) {
                             mmap->mem_start + (headfsize   - mmap->blk_start*f.blksize));
 
             if (mem_unzero_stop - mem_unzero_start > 0) {
-                err = mm::map_into(mem_unzero_start, mem_unzero_stop-mem_unzero_start, PROT_READ, MAP_SHARED, f.headf, f.headfsize);
+                err = mmap_into_ro(mem_unzero_start, mem_unzero_stop-mem_unzero_start, f.headf, f.headfsize);
                 if (err != nil)
                     return err;
             }
@@ -494,7 +495,7 @@ error _Mapping::_remmapblk(int64_t blk, Tid at) {
     }
     // block is inside file - mmap file data
     else {
-        err = mm::map_into(blkmem, 1*f->blksize, PROT_READ, MAP_SHARED, fsfile, blk*f->blksize);
+        err = mmap_into_ro(blkmem, 1*f->blksize, fsfile, blk*f->blksize);
         if (err != nil)
             return err;
     }
@@ -899,7 +900,7 @@ static string h(uint64_t v) {
     return fmt::sprintf("%016lx", v);
 }
 
-// map_zero_ro mmaps read-only zeros into [addr +size) so that region as all zeros.
+// mmap_zero_ro mmaps read-only zeros into [addr +size) so that region as all zeros.
 // created mapping, even after it is accessed, does not consume memory.
 static error _mmap_zero_into_ro(void *addr, size_t size);
 static error mmap_zero_into_ro(void *addr, size_t size) {
@@ -924,3 +925,9 @@ static error _mmap_zero_into_ro(void *addr, size_t size) {
         return err;
     return nil;
 }
+
+// mmap_into_ro mmaps read-only fd[offset +size) into [addr +size).
+// The mapping is created with MAP_SHARED.
+static error mmap_into_ro(void *addr, size_t size, const os::File &f, off_t offset) {
+    return mm::map_into(addr, size, PROT_READ, MAP_SHARED, f, offset);
+}