.

bigfile/tests/test_virtmem.c

@@ -201,6 +201,7 @@ const char *__tsan_default_options()
 
 
 /* whether appropriate page of vma is mapped */
+// XXX BUG on out-of-bounds
 int M(VMA *vma, pgoff_t idx) {  return bitmap_test_bit(vma->page_ismappedv, idx);   }
 
 
@@ -1112,6 +1113,90 @@ void test_pagefault_savestate()
 #undef  CHECK_NOPAGE
 }
 
+/* ---------------------------------------- */
+
+/* test access to file mappings with file having .mmap* instead of .loadblk
+ *
+ * mmapbase is virtmem mode used with wcfs: RAM pages are used only for dirtied
+ * data and everything else comes as read-only mmap from wcfs file.
+ */
+
+/* file that mmaps blkdata */   // XXX
+struct BigFileMMap {
+    BigFile;
+    int fd;  /* fd of file to mmap */
+};
+typedef struct BigFileMMap BigFileMMap;
+
+void *mmapfile_mmap_setup_read(BigFile *file, blk_t blk, size_t blklen, VMA *vma) {
+    BigFileMMap *f = upcast(BigFileMMap*, file);
+    void *addr;
+
+    addr = mmap(NULL, blklen*f->blksize, PROT_READ, MAP_SHARED, f->fd, blk*f->blksize);
+    if (addr == MAP_FAILED)
+        addr = NULL;
+
+    return addr;
+}
+
+void mmapfile_release(BigFile *file) {
+    BigFileMMap *f = upcast(BigFileMMap*, file);
+    int err;
+
+    err = close(f->fd);
+    BUG_ON(err);
+}
+
+static const struct bigfile_ops mmapfile_ops = {
+    .loadblk            = NULL,
+//  .storeblk           = mmapfile_storeblk,
+    .mmap_setup_read    = mmapfile_mmap_setup_read,
+    .release            = mmapfile_release,
+};
+
+
+void test_file_access_mmapbase(void)
+{
+    RAM *ram;
+    BigFileH fh_struct, *fh = &fh_struct;
+    VMA vma_struct, *vma = &vma_struct;
+    size_t PS;
+    int fd, err;
+
+    diag("Testing file access (mmap base)");
+
+    ram = ram_new(NULL, NULL);
+    ok1(ram);
+    PS = ram->pagesize;
+
+    /* ensure we are starting from new ram */
+    ok1(list_empty(&ram->lru_list));
+
+    /* setup mmaped id file */
+    char path[] = "/tmp/bigfile_mmap.XXXXXX";
+    fd = mkstemp(path);
+    ok1(fd != -1);
+    err = unlink(path);
+    ok1(!err);
+
+    BigFileMMap fileid = {
+        .blksize    = ram->pagesize,    /* artificially blksize = pagesize */
+        .file_ops   = &mmapfile_ops,
+        .fd         = fd,
+    };
+
+    err = fileh_open(fh, &fileid, ram);
+    ok1(!err);
+
+/* implicitly use fileh=fh */
+#define CHECK_PAGE(page, pgoffset, pgstate, pgrefcnt)   \
+                __CHECK_PAGE(page, fh, pgoffset, pgstate, pgrefcnt)
+#define CHECK_NOPAGE(pgoffset)  __CHECK_NOPAGE(fh, pgoffset)
+
+    err = fileh_mmap(vma, fh, 100, 4);
+    ok1(!err);
+
+}
 
 
 // TODO test for loadblk that returns -1
@@ -1120,9 +1205,12 @@ int main()
 {
     tap_fail_callback = abort;  // XXX to catch failure immediately
 
+  if (0) {
     test_vmamap();
     test_file_access_synthetic();
     test_file_access_pagefault();
     test_pagefault_savestate();
+  }
+    test_file_access_mmapbase();
     return 0;
 }

include/wendelin/bigfile/file.h

@@ -32,6 +32,9 @@
 #include <stddef.h>
 #include <wendelin/bigfile/types.h>
 
+// XXX move everything into virtmem.h ?
+#include <wendelin/bigfile/virtmem.h>   // for VMA
+
 
 /* BigFile base class
  *
@@ -69,7 +72,9 @@ struct bigfile_ops {
     int  (*storeblk) (BigFile *file, blk_t blk, const void *buf);
 
 
-    /* mmap_read is called to mmap read-only file[blk +blklen) into @addr.
+    /* mmap_setup_read is called to setup new read-only mapping of file[blk +blklen).
+     *
+     * The mapping will be used as the base read-only layer for vma.
      *
      * XXX mmap_read -> !loadblk ?
      * NOTE blk and blklen are in blocks, not pages.
@@ -77,9 +82,10 @@ struct bigfile_ops {
      * @addr    NULL - mmap at anywhere,    !NULL - mmap exactly at addr.
      * @return  !NULL - mapped there,       NULL - error.
      */
-    void* (*mmap_read) (BigFile *file, void *addr, blk_t blk, size_t blklen);
+//    void* (*mmap_read) (BigFile *file, void *addr, blk_t blk, size_t blklen);
+    void* (*mmap_setup_read) (BigFile *file, blk_t blk, size_t blklen, VMA *vma);
 
-    // - mmap_read(vma)             setup initial read-only mmap
+    // - mmap_setup_read(vma)       setup initial read-only mmap
     // - mresync(vma, was_dirtyv)   forget RW dirty pages -> mmap them back read-only to file data
     // - munmap(vma)                before VMA is unmapped
 

t/t_utils.h

@@ -2,7 +2,7 @@
 #define _WENDELIN_TESTING_UTILS_H_
 
 /* Wendelin.bigfile | various testing utilities
- * Copyright (C) 2014-2015  Nexedi SA and Contributors.
+ * Copyright (C) 2014-2019  Nexedi SA and Contributors.
  *                          Kirill Smelkov <kirr@nexedi.com>
  *
  * This program is free software: you can Use, Study, Modify and Redistribute
@@ -25,6 +25,7 @@
 #include <wendelin/bigfile/ram.h>
 
 /* access to vma memory as byte[] and blk_t[] */
+// XXX BUG on out-of-bound access
 #define b(vma, idx) ( ((volatile uint8_t *)vma->addr_start) [ idx ] )
 #define B(vma, idx) ( ((volatile blk_t *)vma->addr_start)   [ idx ] )