And with this patch, mount points other than the 26 drives are listed.
For example, I created a separate disk, formatted it as NTFS, mounted
it at S:\, added some files, unmounted it from S:\, and finally
mounted it at C:\Users\bruno\mt_scratch.
The test program now reports:
??? C:\ ??? NFTS local
??? P:\ C:\Users\Public NFTS local
??? T:\ \\larid\tmp NTFS remote
??? C:\Users\bruno\mt_scratch\ ??? NTFS local
2025-03-19 Bruno Haible <br...@clisp.org>
mountlist: Improve implementation on native Windows.
* lib/mountlist.c (read_file_system_list) [_WIN32 && !__CYGWIN__]:
Also return the mount points inside the file systems.
diff --git a/lib/mountlist.c b/lib/mountlist.c
index 23ebdf6750..2ed4b138ba 100644
--- a/lib/mountlist.c
+++ b/lib/mountlist.c
@@ -1195,7 +1195,96 @@ read_file_system_list (bool need_fs_type)
}
}
}
-
+ {
+ /* Windows also has true mount points, called "mounted folders". See
+
<https://learn.microsoft.com/en-us/windows/win32/fileio/volume-mount-points>
+ For testing:
<https://learn.microsoft.com/en-us/windows-server/storage/disk-management/assign-a-mount-point-folder-path-to-a-drive>
*/
+ /* Enumerate the volumes. See
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findfirstvolumew>
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findnextvolumew>
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findvolumeclose>
*/
+ wchar_t vol_name[MAX_PATH + 1];
+ HANDLE h = FindFirstVolumeW (vol_name, sizeof (vol_name) / sizeof
(vol_name[0]));
+ if (h != INVALID_HANDLE_VALUE)
+ {
+ do
+ {
+ /* Look where the volume vol_name is mounted.
+ There are two APIs for doing this:
+ - FindFirstVolumeMountPointW, FindNextVolumeMountPointW,
+ FindVolumeMountPointClose. This API always fails with
+ error code ERROR_ACCESS_DENIED.
+ - GetVolumePathNamesForVolumeNameW. This API works but
+ may require a significantly larger buffer.
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getvolumepathnamesforvolumenamew>
*/
+ wchar_t stack_buf[MAX_PATH + 2];
+ wchar_t *malloced_buf = NULL;
+ wchar_t *buf = stack_buf;
+ DWORD bufsize = sizeof (stack_buf) / sizeof (wchar_t);
+ BOOL success;
+ for (;;)
+ {
+ success = GetVolumePathNamesForVolumeNameW (vol_name, buf,
bufsize, &bufsize);
+ if (!success && GetLastError () == ERROR_MORE_DATA)
+ {
+ free (malloced_buf);
+ malloced_buf = (wchar_t *) xmalloc (bufsize * sizeof
(wchar_t));
+ buf = malloced_buf;
+ }
+ else
+ break;
+ }
+ if (success)
+ {
+ wchar_t *mount_dir = buf;
+ while (*mount_dir != L'\0')
+ {
+ /* Drive mounts are already handled above. */
+ if (!(mount_dir[0] >= L'A' && mount_dir[0] <= L'Z'
+ && mount_dir[1] == L':' && mount_dir[2] == L'\\'
+ && mount_dir[3] == L'\0'))
+ {
+ char mountdir[MAX_PATH + 1];
+ size_t mountdir_len = wcstombs (mountdir, mount_dir,
sizeof (mountdir));
+ if (mountdir_len > 0 && mountdir_len <= MAX_PATH)
+ {
+ char fs_name[MAX_PATH + 1];
+ /* Get the name of the file system. See:
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getvolumeinformationa>.
*/
+ if (GetVolumeInformation (mountdir, NULL, 0, NULL,
NULL, NULL,
+ fs_name, sizeof fs_name))
+ {
+ me = xmalloc (sizeof *me);
+ me->me_mountdir = xstrdup (mountdir);
+ me->me_remote = false;
+ /* Here we could use vol_name, something like
'\\?\Volume{...}'. */
+ me->me_devname = NULL;
+ me->me_mntroot = NULL;
+ me->me_dev = (dev_t) -1;
+ me->me_dummy = 0;
+ me->me_type = xstrdup (fs_name);
+ me->me_type_malloced = 1;
+
+ /* Add to the linked list. */
+ *mtail = me;
+ mtail = &me->me_next;
+ }
+ }
+ else
+ {
+ /* mount_dir is too long or not convertible to the
+ locale encoding. */
+ }
+ }
+ mount_dir += wcslen (mount_dir) + 1;
+ }
+ }
+ free (malloced_buf);
+ }
+ while (FindNextVolumeW (h, vol_name, sizeof (vol_name) / sizeof
(vol_name[0])));
+ FindVolumeClose (h);
+ }
+ }
#endif
*mtail = NULL;
