[svn-r16082] Purpose: Fix a problem in the file unmounting code

Description: Fixes a problem in H5F_close_mounts where it wouldn't correctly
reshape the "child" array when unmounting files.  Test added for this case.
Also fixed a potential bug in H5F_unmount where that routine reshapes the child
array.

Tested: kagiso linew smirom (h5committest)

3 files changed, 140 insertions, 5 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index a90a249..a6ea23d 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -127,6 +127,8 @@ Bug Fixes since HDF5-1.8.0 release
 
     Library
     -------
+      - Fixed a bug that could cause problems when "automatically" unmounting
+            multiple files.  (NAF - 2008/11/17)
       - H5Ovisit and H5Ovisit_by_name will now properly terminate when the
             callback function returns a positive value on the starting object.
             (NAF - 2008/11/03)
diff --git a/src/H5Fmount.c b/src/H5Fmount.c
index 0c31be6..a428cd6 100644
--- a/src/H5Fmount.c
+++ b/src/H5Fmount.c
@@ -79,8 +79,10 @@ H5F_close_mounts(H5F_t *f)
 
     HDassert(f);
 
-    /* Unmount all child files */
-    for (u = 0; u < f->shared->mtab.nmounts; u++) {
+    /* Unmount all child files.  Loop backwards to avoid having to adjust u when
+     * a file is unmounted.  Note that we rely on unsigned u "wrapping around"
+     * to terminate the loop. */
+    for (u = f->shared->mtab.nmounts - 1; u < f->shared->mtab.nmounts; u--) {
         /* Only unmount children mounted to this top level file structure */
         if(f->shared->mtab.child[u].file->parent == f) {
             /* Detach the child file from the parent file */
@@ -93,10 +95,16 @@ H5F_close_mounts(H5F_t *f)
             /* Close the child file */
             if(H5F_try_close(f->shared->mtab.child[u].file) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close child file")
+
+            /* Eliminate the mount point from the table */
+            HDmemmove(f->shared->mtab.child + u, f->shared->mtab.child + u + 1,
+                (f->shared->mtab.nmounts - u - 1) * sizeof(f->shared->mtab.child[0]));
+            f->shared->mtab.nmounts--;
+            f->nmounts--;
         }
     } /* end if */
-    f->shared->mtab.nmounts -= f->nmounts;
-    f->nmounts = 0;
+
+    HDassert(f->nmounts == 0);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -390,7 +398,7 @@ H5F_unmount(H5G_loc_t *loc, const char *name, hid_t dxpl_id)
 
     /* Eliminate the mount point from the table */
     HDmemmove(parent->shared->mtab.child + child_idx, parent->shared->mtab.child + child_idx + 1,
-            (parent->shared->mtab.nmounts-child_idx) * sizeof(parent->shared->mtab.child[0]));
+            (parent->shared->mtab.nmounts - child_idx - 1) * sizeof(parent->shared->mtab.child[0]));
     parent->shared->mtab.nmounts -= 1;
     parent->nmounts -= 1;
 
diff --git a/test/mount.c b/test/mount.c
index 25af851..77ec3b6 100644
--- a/test/mount.c
+++ b/test/mount.c
@@ -4202,6 +4202,130 @@ error:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	test_multisharedclose
+ *
+ * Purpose: Test that multiple files mounted to a shared mount structure
+ *          can be properly closed by closing the groups holding them open.
+ *
+ * Return:	Success:	0
+ *
+ *		Failure:	number of errors
+ *
+ * Programmer:	Neil Fortner
+ *              Friday, November 14, 2008
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+ static int
+test_multisharedclose(hid_t fapl)
+{
+    hid_t fid1 = -1, fid2 = -1; /* File IDs */
+    hid_t gid1 = -1, gid2 = -1, gid3 = -1;
+    char    filename1[NAME_BUF_SIZE],
+            filename2[NAME_BUF_SIZE],
+            filename3[NAME_BUF_SIZE],
+            filename4[NAME_BUF_SIZE]; 	/* Name of files to mount */
+
+    TESTING("closing multiple shared mounts");
+
+    h5_fixname(FILENAME[0], fapl, filename1, sizeof filename1);
+    h5_fixname(FILENAME[1], fapl, filename2, sizeof filename2);
+    h5_fixname(FILENAME[2], fapl, filename3, sizeof filename3);
+    h5_fixname(FILENAME[3], fapl, filename4, sizeof filename4);
+
+    /* Create master file with three groups to serve as mount points */
+    if ((fid1 = H5Fcreate(filename4, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "mnt1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "mnt2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "mnt3", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fclose(fid1) < 0) TEST_ERROR
+
+    /* Create child file with group */
+    if ((fid1 = H5Fcreate(filename1, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "grp", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fclose(fid1) < 0) TEST_ERROR
+
+    /* Create child file with group */
+    if ((fid1 = H5Fcreate(filename2, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "grp", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fclose(fid1) < 0) TEST_ERROR
+
+    /* Create child file with group */
+    if ((fid1 = H5Fcreate(filename3, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Gclose(H5Gcreate(fid1, "grp", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fclose(fid1) < 0) TEST_ERROR
+
+
+    /* Open master and child 1 and mount child 1 to master */
+    if ((fid1 = H5Fopen(filename4, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if ((fid2 = H5Fopen(filename1, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fmount(fid1, "mnt1", fid2, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Open the group in child 1 */
+    if ((gid1 = H5Gopen(fid1, "mnt1/grp", H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Close both files.  They will be held open by gid1 */
+    if (H5Idec_ref(fid2) < 0) TEST_ERROR
+    if (H5Idec_ref(fid1) < 0) TEST_ERROR
+
+
+    /* Open master and child 2 and mount child 2 to master */
+    if ((fid1 = H5Fopen(filename4, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if ((fid2 = H5Fopen(filename2, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fmount(fid1, "mnt2", fid2, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Open the group in child 2 */
+    if ((gid2 = H5Gopen(fid1, "mnt2/grp", H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Close both files.  They will be held open by gid2 */
+    if (H5Idec_ref(fid2) < 0) TEST_ERROR
+    if (H5Idec_ref(fid1) < 0) TEST_ERROR
+
+
+    /* Open master and child 3 and mount child 3 to master */
+    if ((fid1 = H5Fopen(filename4, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if ((fid2 = H5Fopen(filename3, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0) TEST_ERROR
+    if (H5Fmount(fid1, "mnt3", fid2, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Open the group in child 3 */
+    if ((gid3 = H5Gopen(fid1, "mnt3/grp", H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Close both files.  They will be held open by gid3 */
+    if (H5Idec_ref(fid2) < 0) TEST_ERROR
+    if (H5Idec_ref(fid1) < 0) TEST_ERROR
+
+
+    /* Close gid1.  This will close child 1. */
+    if (H5Idec_ref(gid1) < 0) TEST_ERROR
+
+    /* Close gid2.  This will close child 2. */
+    if (H5Idec_ref(gid2) < 0) TEST_ERROR
+
+    /* Close gid3.  This will close child 3 and the master file. */
+    if (H5Idec_ref(gid3) < 0) TEST_ERROR
+
+    /* Check that all file IDs have been closed */
+    if(H5I_nmembers(H5I_FILE) != 0) TEST_ERROR
+    if(H5F_sfile_assert_num(0) < 0) TEST_ERROR
+
+    PASSED();
+    return 0;
+
+error:
+    H5E_BEGIN_TRY {
+    H5Gclose(gid1);
+    H5Gclose(gid2);
+    H5Gclose(gid3);
+    H5Fclose(fid2);
+    H5Fclose(fid2);
+    } H5E_END_TRY;
+    return 1;
+} /* end test_multisharedclose() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	main
  *
  * Purpose:	Test file mounting
@@ -4257,6 +4381,7 @@ main(void)
     nerrors += test_symlink(fapl);
     nerrors += test_sharedacc(fapl);
     nerrors += test_sharedclose(fapl);
+    nerrors += test_multisharedclose(fapl);
 
     if (nerrors) goto error;