After migrating from GetLogicalDrives to Find(First|Next)VolumeW, mapped
network drives no longer showed up in getmntent output. To fix that,
also iterate GetLogicalDriveStringsW when builing dos_drive_mappings,
and merge with volume mounts (skipping any volume mounts that are just
mounted on the root of a drive, and replacing the dos mounts in the
mapping for a volume which is mounted on both a drive root and a
directory).
Fixes: 04a5b072940cc ("Cygwin: expose all windows volume mount points.")
Addresses: https://cygwin.com/pipermail/cygwin/2025-February/257384.html
Signed-off-by: Jeremy Drake <cyg...@jdrake.com>
---
winsup/cygwin/mount.cc | 145 ++++++++++++++++++++++++++++++++---------
1 file changed, 113 insertions(+), 32 deletions(-)
diff --git a/winsup/cygwin/mount.cc b/winsup/cygwin/mount.cc
index b8d8d4a974..ab07c5abef 100644
--- a/winsup/cygwin/mount.cc
+++ b/winsup/cygwin/mount.cc
@@ -1986,6 +1986,40 @@ endmntent (FILE *)
return 1;
}
+static bool
+resolve_dos_device (const wchar_t *dosname, wchar_t *devpath)
+{
+ if (QueryDosDeviceW (dosname, devpath, NT_MAX_PATH))
+ {
+ /* The DOS drive mapping can be another symbolic link. If so,
+ the mapping won't work since the section name is the name
+ after resolving all symlinks. Resolve symlinks here, too. */
+ for (int syml_cnt = 0; syml_cnt < SYMLOOP_MAX; ++syml_cnt)
+ {
+ UNICODE_STRING upath;
+ OBJECT_ATTRIBUTES attr;
+ NTSTATUS status;
+ HANDLE h;
+
+ RtlInitUnicodeString (&upath, devpath);
+ InitializeObjectAttributes (&attr, &upath, OBJ_CASE_INSENSITIVE,
+ NULL, NULL);
+ status = NtOpenSymbolicLinkObject (&h, SYMBOLIC_LINK_QUERY, &attr);
+ if (!NT_SUCCESS (status))
+ break;
+ RtlInitEmptyUnicodeString (&upath, devpath, (NT_MAX_PATH - 1)
+ * sizeof (WCHAR));
+ status = NtQuerySymbolicLinkObject (h, &upath, NULL);
+ NtClose (h);
+ if (!NT_SUCCESS (status))
+ break;
+ devpath[upath.Length / sizeof (WCHAR)] = L'\0';
+ }
+ return true;
+ }
+ return false;
+}
+
dos_drive_mappings::dos_drive_mappings ()
: mappings(0)
, cur_mapping(0)
@@ -1995,6 +2029,44 @@ dos_drive_mappings::dos_drive_mappings ()
wchar_t vol[64]; /* Long enough for Volume GUID string */
wchar_t *devpath = tp.w_get ();
wchar_t *mounts = tp.w_get ();
+ mapping **nextm = &mappings;
+ mapping *endfirstloop = NULL;
+ DWORD len;
+
+ /* Iterate over all drive letters, fetch the DOS device path */
+ if (!(len = GetLogicalDriveStringsW (NT_MAX_PATH - 1, mounts)) ||
+ len >= NT_MAX_PATH)
+ debug_printf ("GetLogicalDriveStringsW, %E");
+ else {
+ for (wchar_t *mount = mounts; *mount; mount += len + 2)
+ {
+ len = wcslen (mount);
+ mount[--len] = L'\0'; /* Drop trailing backslash */
+ if (resolve_dos_device (mount, devpath))
+ {
+ mapping *m = new mapping ();
+ if (m)
+ {
+ m->dos.path = wcsdup (mount);
+ m->ntdevpath = wcsdup (devpath);
+ if (!m->dos.path || !m->ntdevpath)
+ {
+ free (m->dos.path);
+ free (m->ntdevpath);
+ delete m;
+ continue;
+ }
+ m->dos.len = len;
+ m->ntlen = wcslen (m->ntdevpath);
+ *nextm = endfirstloop = m;
+ nextm = &m->next;
+ }
+ }
+ else
+ debug_printf ("Unable to determine the native mapping for %ls "
+ "(error %E)", mount);
+ }
+ }
/* Iterate over all volumes, fetch the list of DOS paths the volume is
mounted to. */
@@ -2002,43 +2074,22 @@ dos_drive_mappings::dos_drive_mappings ()
if (sh == INVALID_HANDLE_VALUE)
debug_printf ("FindFirstVolumeW, %E");
else {
- mapping **nextm = &mappings;
do
{
- /* Skip drives which are not mounted. */
- DWORD len;
+ /* Skip volumes which are not mounted. */
if (!GetVolumePathNamesForVolumeNameW (vol, mounts, NT_MAX_PATH, &len)
|| mounts[0] == L'\0')
continue;
+ /* Skip volumes which are only mounted to the root of a drive letter:
+ they were handled in the loop above */
+ if (len == 5 && mounts[1] == L':' && mounts[2] == L'\\' && !mounts[3])
+ continue;
+
*wcsrchr (vol, L'\\') = L'\0';
- if (QueryDosDeviceW (vol + 4, devpath, NT_MAX_PATH))
+ if (resolve_dos_device (vol + 4, devpath))
{
- /* The DOS drive mapping can be another symbolic link. If so,
- the mapping won't work since the section name is the name
- after resolving all symlinks. Resolve symlinks here, too. */
- for (int syml_cnt = 0; syml_cnt < SYMLOOP_MAX; ++syml_cnt)
- {
- UNICODE_STRING upath;
- OBJECT_ATTRIBUTES attr;
- NTSTATUS status;
- HANDLE h;
-
- RtlInitUnicodeString (&upath, devpath);
- InitializeObjectAttributes (&attr, &upath,
- OBJ_CASE_INSENSITIVE, NULL, NULL);
- status = NtOpenSymbolicLinkObject (&h, SYMBOLIC_LINK_QUERY,
- &attr);
- if (!NT_SUCCESS (status))
- break;
- RtlInitEmptyUnicodeString (&upath, devpath, (NT_MAX_PATH - 1)
- * sizeof (WCHAR));
- status = NtQuerySymbolicLinkObject (h, &upath, NULL);
- NtClose (h);
- if (!NT_SUCCESS (status))
- break;
- devpath[upath.Length / sizeof (WCHAR)] = L'\0';
- }
mapping *m = new mapping ();
+ bool hadrootmount = false;
if (m)
{
/* store mount point list */
@@ -2063,15 +2114,45 @@ dos_drive_mappings::dos_drive_mappings ()
dos->path = mount;
dos->len = wcslen (dos->path);
dos->path[--dos->len] = L'\0'; /* Drop trailing backslash */
+ if (dos->len == 2 && dos->path[1] == L':')
+ hadrootmount = true;
}
m->ntlen = wcslen (m->ntdevpath);
- *nextm = m;
- nextm = &m->next;
+ if (hadrootmount)
+ {
+ /* This device has already been added to the mappings list
+ in the first loop above, but with only the drive root
+ mount. Find that entry and replace it with the complete
+ list of mounts. */
+ hadrootmount = false;
+ for (mapping *m2 = mappings;
+ endfirstloop && m2 != endfirstloop->next;
+ m2 = m2->next)
+ {
+ if (m->ntlen == m2->ntlen &&
+ !wcscmp (m->ntdevpath, m2->ntdevpath))
+ {
+ free (m2->dos.path);
+ m2->dos.next = m->dos.next;
+ m2->dos.path = m->dos.path;
+ m2->dos.len = m->dos.len;
+ free (m->ntdevpath);
+ delete m;
+ hadrootmount = true;
+ break;
+ }
+ }
+ }
+ if (!hadrootmount)
+ {
+ *nextm = m;
+ nextm = &m->next;
+ }
}
}
else
debug_printf ("Unable to determine the native mapping for %ls "
- "(error %u)", vol, GetLastError ());
+ "(error %E)", vol);
}
while (FindNextVolumeW (sh, vol, 64));
FindVolumeClose (sh);
--
2.48.1.windows.1
