cygwin ChangeLog

2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
	    Christopher Faylor  <me+cygwin@cgf.cx>

	* mount.cc (mount_info::got_usr_bin): Define.
	(mount_info::got_usr_lib): Ditto.
	(mount_info::root_idx): Ditto.
	(mount_info::create_root_entry): Create root entry as immutable and
	flag as automatic.
	(mount_info::init): Remove "Huh?  No /etc/fstab..." warning.
	Unconditionally call from_fstab for user and system tables.  Fill in
	/usr/bin and /usr/lib if they have not been specified in /etc/fstab.
	(oopts): Alphabetize.  Add "override" option to allow overriding
	immutable mount points.
	(mount_info::add_item): Accommodate new MOUNT_IMMUTABLE flag intended
	for root mount.
	(mount_info::add_item): Detect "/usr/bin", "/usr/lib", and "/" and set
	appropriate global state.
	(fillout_mntent): Add ,auto to mount points added by Cygwin DLL.
	(mount): Remove masking of MOUNT_SYSTEM.  Allow user to shoot
	themselves.  Add comment.
	* mount.h (mount_info::got_usr_bin): Declare.
	(mount_info::got_usr_lib): Ditto.
	(mount_info::root_idx): Ditto.
	* include/sys/mount.h: Reformat enum.
	Add MOUNT_{OVERRIDE,IMMUTABLE,AUTOMATIC}.

doc ChangeLog
2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
	    Christopher Faylor  <me+cygwin@cgf.cx>

	* pathnames.sgml (mount-table): Sort mount options and add override
	option.  Add description of root mount handling.

utils ChangeLog
2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
	    Christopher Faylor  <me+cygwin@cgf.cx>

	* mount.cc (oopts): Sort.  Add override option.  Add dummy "auto"
	option for consistency.
	(mount_entries): Avoid adding auto-mounted entries to -m output.

	* utils.sgml: Sort mount options.  Add description of override option.

winsup/cygwin/ChangeLog

@@ -1,3 +1,29 @@
+2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
+	    Christopher Faylor  <me+cygwin@cgf.cx>
+
+	* mount.cc (mount_info::got_usr_bin): Define.
+	(mount_info::got_usr_lib): Ditto.
+	(mount_info::root_idx): Ditto.
+	(mount_info::create_root_entry): Create root entry as immutable and
+	flag as automatic.
+	(mount_info::init): Remove "Huh?  No /etc/fstab..." warning.
+	Unconditionally call from_fstab for user and system tables.  Fill in
+	/usr/bin and /usr/lib if they have not been specified in /etc/fstab.
+	(oopts): Alphabetize.  Add "override" option to allow overriding
+	immutable mount points.
+	(mount_info::add_item): Accommodate new MOUNT_IMMUTABLE flag intended
+	for root mount.
+	(mount_info::add_item): Detect "/usr/bin", "/usr/lib", and "/" and set
+	appropriate global state.
+	(fillout_mntent): Add ,auto to mount points added by Cygwin DLL.
+	(mount): Remove masking of MOUNT_SYSTEM.  Allow user to shoot
+	themselves.  Add comment.
+	* mount.h (mount_info::got_usr_bin): Declare.
+	(mount_info::got_usr_lib): Ditto.
+	(mount_info::root_idx): Ditto.
+	* include/sys/mount.h: Reformat enum.
+	Add MOUNT_{OVERRIDE,IMMUTABLE,AUTOMATIC}.
+
 2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
 
 	* cygheap.h (cwdstuff): Convert to class.  Make posix and dir private.

winsup/cygwin/include/sys/mount.h

@@ -17,21 +17,26 @@ extern "C" {
 
 enum
 {
-  MOUNT_SYMLINK =	0x0001,	/* "mount point" is a symlink */
+  MOUNT_SYMLINK =	0x00001,	/* "mount point" is a symlink */
-  MOUNT_BINARY =	0x0002,	/* "binary" format read/writes */
+  MOUNT_BINARY =	0x00002,	/* "binary" format read/writes */
-  MOUNT_SYSTEM =	0x0008,	/* mount point came from system table */
+  MOUNT_SYSTEM =	0x00008,	/* mount point came from system table */
-  MOUNT_EXEC   =	0x0010,	/* Any file in the mounted directory gets 'x' bit */
+  MOUNT_EXEC   =	0x00010,	/* Any file in the mounted directory
-  MOUNT_CYGDRIVE   =	0x0020,	/* mount point refers to cygdrive device mount */
+					   gets 'x' bit */
-  MOUNT_CYGWIN_EXEC =	0x0040,	/* file or directory is or contains a cygwin
+  MOUNT_CYGDRIVE   =	0x00020,	/* mount point refers to cygdrive
-				   executable */
+					   device mount */
-  MOUNT_MIXED	=	0x0080,	/* reads are text, writes are binary
+  MOUNT_CYGWIN_EXEC =	0x00040,	/* file or directory is or contains a
+					   cygwin executable */
+  MOUNT_MIXED	=	0x00080,	/* reads are text, writes are binary
 					   not yet implemented */
-  MOUNT_NOTEXEC =	0x0100,	/* don't check files for executable magic */
+  MOUNT_NOTEXEC =	0x00100,	/* don't check files for executable magic */
-  MOUNT_DEVFS =		0x0200,	/* /device "filesystem" */
+  MOUNT_DEVFS =		0x00200,	/* /device "filesystem" */
-  MOUNT_PROC =		0x0400,	/* /proc "filesystem" */
+  MOUNT_PROC =		0x00400,	/* /proc "filesystem" */
-  MOUNT_RO =		0x1000, /* read-only "filesystem" */
+  MOUNT_RO =		0x01000,	/* read-only "filesystem" */
-  MOUNT_NOACL =		0x2000, /* support reading/writing ACLs */
+  MOUNT_NOACL =		0x02000,	/* support reading/writing ACLs */
-  MOUNT_NOPOSIX =	0x4000  /* Case insensitve path handling */
+  MOUNT_NOPOSIX =	0x04000,	/* Case insensitve path handling */
+  MOUNT_OVERRIDE =	0x08000,	/* Allow overriding of root */
+  MOUNT_IMMUTABLE =	0x10000,	/* Mount point can't be changed */
+  MOUNT_AUTOMATIC =	0x20000		/* Mount point was added automatically */
 };
 
 int mount (const char *, const char *, unsigned __flags);

winsup/cygwin/mount.cc

@@ -31,6 +31,7 @@ details. */
 #include <ntdll.h>
 #include <wchar.h>
 #include <stdio.h>
+#include <assert.h>
 
 /* Determine if path prefix matches current cygdrive */
 #define iscygdrive(path) \
@@ -44,6 +45,10 @@ details. */
 #define isproc(path) \
   (path_prefix_p (proc, (path), proc_len, false))
 
+bool mount_info::got_usr_bin;
+bool mount_info::got_usr_lib;
+int mount_info::root_idx = -1;
+
 /* is_unc_share: Return non-zero if PATH begins with //server/share
 		 or with one of the native prefixes //./ or //?/
    This function is only used to test for valid input strings.
@@ -298,10 +303,12 @@ fs_info::update (PUNICODE_STRING upath, HANDLE in_vol)
 inline void
 mount_info::create_root_entry (const PWCHAR root)
 {
-  /* Create a default root dir from the path the Cygwin DLL is in. */
+ /* Create a default root dir derived from the location of the Cygwin DLL.
+    The entry is immutable, unless the "override" option is given in /etc/fstab. */
   char native_root[PATH_MAX];
   sys_wcstombs (native_root, PATH_MAX, root);
-  mount_table->add_item (native_root, "/", MOUNT_SYSTEM | MOUNT_BINARY);
+  mount_table->add_item (native_root, "/",
+			 MOUNT_SYSTEM | MOUNT_BINARY | MOUNT_OVERRIDE | MOUNT_AUTOMATIC);
   /* Create a default cygdrive entry.  Note that this is a user entry.
      This allows to override it with mount, unless the sysadmin created
      a cygdrive entry in /etc/fstab. */
@@ -322,12 +329,28 @@ mount_info::init ()
   pathend = wcpcpy (path, cygwin_shared->installation_root);
   create_root_entry (path);
   pathend = wcpcpy (pathend, L"\\etc\\fstab");
-  if (from_fstab (false, path, pathend)   /* The single | is correct! */
-      | from_fstab (true, path, pathend))
-      return;
 
-  /* FIXME: Remove warning message before releasing 1.7.0. */
+  from_fstab (false, path, pathend);
-  small_printf ("Huh?  No /etc/fstab file in %W?  Using default root and cygdrive prefix...\n", path);
+  from_fstab (true, path, pathend);
+
+  if (!got_usr_bin || !got_usr_lib)
+    {
+      char native[PATH_MAX];
+      assert (root_idx != -1);
+      char *p = stpcpy (native, mount[root_idx].native_path);
+      if (!got_usr_bin)
+      {
+	stpcpy (p, "\\bin");
+	mount_table->add_item (native, "/usr/bin",
+			       MOUNT_SYSTEM | MOUNT_BINARY | MOUNT_AUTOMATIC | MOUNT_CYGWIN_EXEC);
+      }
+      if (!got_usr_lib)
+      {
+	stpcpy (p, "\\lib");
+	mount_table->add_item (native, "/usr/lib",
+			       MOUNT_SYSTEM | MOUNT_BINARY | MOUNT_AUTOMATIC);
+      }
+    }
 }
 
 static void
@@ -835,18 +858,19 @@ struct opt
   bool clear;
 } oopts[] =
 {
-  {"user", MOUNT_SYSTEM, 1},
-  {"nouser", MOUNT_SYSTEM, 0},
-  {"binary", MOUNT_BINARY, 0},
-  {"text", MOUNT_BINARY, 1},
-  {"exec", MOUNT_EXEC, 0},
-  {"notexec", MOUNT_NOTEXEC, 0},
-  {"cygexec", MOUNT_CYGWIN_EXEC, 0},
-  {"nosuid", 0, 0},
   {"acl", MOUNT_NOACL, 1},
+  {"binary", MOUNT_BINARY, 0},
+  {"cygexec", MOUNT_CYGWIN_EXEC, 0},
+  {"exec", MOUNT_EXEC, 0},
   {"noacl", MOUNT_NOACL, 0},
+  {"nosuid", 0, 0},
+  {"notexec", MOUNT_NOTEXEC, 0},
+  {"nouser", MOUNT_SYSTEM, 0},
+  {"override", MOUNT_OVERRIDE, 0},
+  {"posix=0", MOUNT_NOPOSIX, 0},
   {"posix=1", MOUNT_NOPOSIX, 1},
-  {"posix=0", MOUNT_NOPOSIX, 0}
+  {"text", MOUNT_BINARY, 1},
+  {"user", MOUNT_SYSTEM, 1}
 };
 
 static bool
@@ -1054,7 +1078,7 @@ mount_info::write_cygdrive_info (const char *cygdrive_prefix, unsigned flags)
       set_errno (EINVAL);
       return -1;
     }
-  /* Don't allow to override a system cygdrive prefix. */
+  /* Don't allow overriding of a system cygdrive prefix. */
   if (cygdrive_flags & MOUNT_SYSTEM)
     {
       set_errno (EPERM);
@@ -1238,14 +1262,26 @@ mount_info::add_item (const char *native, const char *posix,
     {
       if (!strcmp (mount[i].posix_path, posixtmp))
 	{
-	  /* Don't allow to override a system mount with a user mount. */
+	  /* Don't allow overriding of a system mount with a user mount. */
 	  if ((mount[i].flags & MOUNT_SYSTEM) && !(mountflags & MOUNT_SYSTEM))
 	    {
 	      set_errno (EPERM);
 	      return -1;
 	    }
-	  if ((mount[i].flags & MOUNT_SYSTEM) == (mountflags & MOUNT_SYSTEM))
+	  if ((mount[i].flags & MOUNT_SYSTEM) != (mountflags & MOUNT_SYSTEM))
+	    continue;
+	  else if (!(mount[i].flags & MOUNT_IMMUTABLE))
 	    break;
+	  else if (mountflags & MOUNT_OVERRIDE)
+	    {
+	      mountflags |= MOUNT_IMMUTABLE;
+	      break;
+	    }
+	  else
+	    {
+	      set_errno (EPERM);
+	      return -1;
+	    }
 	}
     }
 
@@ -1257,6 +1293,16 @@ mount_info::add_item (const char *native, const char *posix,
 
   if (i == nmounts)
     nmounts++;
+
+  if (strcmp (posixtmp, "/usr/bin") == 0)
+    got_usr_bin = true;
+
+  if (strcmp (posixtmp, "/usr/lib") == 0)
+    got_usr_lib = true;
+
+  if (posixtmp[0] == '/' && posixtmp[1] == '\0')
+    root_idx = i;
+
   mount[i].init (nativetmp, posixtmp, mountflags);
   sort ();
 
@@ -1301,8 +1347,8 @@ mount_info::del_item (const char *path, unsigned flags)
 	   ? !strcmp (mount[ent].posix_path, pathtmp)
 	   : strcasematch (mount[ent].native_path, pathtmp)))
 	{
-	  /* Don't allow to remove a system mount. */
+	  /* Don't allow removal of a system mount. */
-	  if ((mount[ent].flags & MOUNT_SYSTEM))
+	  if (mount[ent].flags & MOUNT_SYSTEM)
 	    {
 	      set_errno (EPERM);
 	      return -1;
@@ -1407,9 +1453,12 @@ fillout_mntent (const char *native_path, const char *posix_path, unsigned flags)
   if (!(flags & MOUNT_SYSTEM))		/* user mount */
     strcat (_my_tls.locals.mnt_opts, (char *) ",user");
 
-  if ((flags & MOUNT_CYGDRIVE))		/* cygdrive */
+  if (flags & MOUNT_CYGDRIVE)		/* cygdrive */
     strcat (_my_tls.locals.mnt_opts, (char *) ",noumount");
 
+  if (flags & (MOUNT_AUTOMATIC | MOUNT_CYGDRIVE))
+    strcat (_my_tls.locals.mnt_opts, (char *) ",auto");
+
   ret.mnt_opts = _my_tls.locals.mnt_opts;
 
   ret.mnt_freq = 1;
@@ -1487,8 +1536,9 @@ mount_item::init (const char *native, const char *posix, unsigned mountflags)
 extern "C" int
 mount (const char *win32_path, const char *posix_path, unsigned flags)
 {
+  /* FIXME: Should we disallow setting MOUNT_SYSTEM in flags since it
+     isn't really supported except from fstab? */
   int res = -1;
-  flags &= ~MOUNT_SYSTEM;
 
   myfault efault;
   if (efault.faulted (EFAULT))

winsup/cygwin/mount.h

@@ -104,6 +104,10 @@ class mount_info
   int nmounts;
   mount_item mount[MAX_MOUNTS];
 
+  static bool got_usr_bin;
+  static bool got_usr_lib;
+  static int root_idx;
+
   /* cygdrive_prefix is used as the root of the path automatically
      prepended to a path when the path has no associated mount.
      cygdrive_flags are the default flags for the cygdrives. */

winsup/doc/ChangeLog

@@ -1,3 +1,9 @@
+2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
+	    Christopher Faylor  <me+cygwin@cgf.cx>
+
+	* pathnames.sgml (mount-table): Sort mount options and add override
+	option.  Add description of root mount handling.
+
 2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
 
 	* pathnames.sgml (pathnames-unusual): Talk about using UTF-8 in C

winsup/doc/pathnames.sgml

@@ -71,21 +71,22 @@ posix=[0|1].  The meaning of the options is as follows.</para>
               implement real POSIX permissions (default).  This flag only
 	      affects filesystems supporting ACLs (NTFS) and is ignored
 	      otherwise.
+  binary    - Files default to binary mode (default).
+  cygexec   - Treat all files below mount point as cygwin executables.
+  exec      - Treat all files below mount point as executable.
   noacl     - Cygwin ignores filesystem ACLs and only fakes a subset of
 	      permission bits based on the DOS readonly attribute.  This
 	      behaviour is the default on FAT and FAT32.  The flag is
 	      ignored on NFS filesystems.
-  binary   - Files default to binary mode (default).
-  text     - Files default to CRLF text mode line endings.
-  nouser   - Mount is a system-wide mount.
-  user     - Mount is a user mount.
-  exec     - Treat all files below mount point as executable.
-  notexec  - Treat all files below mount point as not executable.
-  cygexec  - Treat all files below mount point as cygwin executables.
   nosuid    - No suid files are allowed (currently unimplemented).
+  notexec   - Treat all files below mount point as not executable.
+  nouser    - Mount is a system-wide mount.
+  override  - Force the override of an immutable mount point (currently "/").
   posix=0   - Switch off case sensitivity for paths under this mount point.
   posix=1   - Switch on case sensitivity for paths under this mount point
 	      (default).
+  text      - Files default to CRLF text mode line endings.
+  user      - Mount is a user mount.
 </screen>
 
 <para>While normally the execute permission bits are used to evaluate
@@ -105,8 +106,16 @@ overhead of opening each file to check for a '#!'.  The
 but also prevents Cygwin from setting up commands and environment variables
 for a normal Windows program, adding another small performance gain.  The
 opposite of these options is the <literal>notexec</literal> option, which
-means that no files should be marked as executable under that mount point.
+means that no files should be marked as executable under that mount point.</para>
-</para>
+<para>A correct root directory is quite essential to the operation of
+Cygwin.  A default root directory is evaluated at startup so a
+<filename>fstab</filename> entry for the root directory is not necessary.
+If it's wrong, nothing will work as expected.  Therefore, the root directory
+evaluated by Cygwin itself is treated as an immutable mount point and can't
+be overridden in /etc/fstab... unless you think you really know what you're
+doing.  In this case, use the <literal>override</literal> flag in the options
+field in the <filename>/etc/fstab</filename> file.  Since this is a dangerous
+thing to do, do so at your own risk.</para>
 
 <para><literal>nouser</literal> mount points are not overridable by a later
 call to <command>mount</command>.

winsup/utils/ChangeLog

@@ -1,3 +1,12 @@
+2009-05-13  Corinna Vinschen  <corinna@vinschen.de>
+	    Christopher Faylor  <me+cygwin@cgf.cx>
+
+	* mount.cc (oopts): Sort.  Add override option.  Add dummy "auto"
+	option for consistency.
+	(mount_entries): Avoid adding auto-mounted entries to -m output.
+
+	* utils.sgml: Sort mount options.  Add description of override option.
+
 2009-05-11  Corinna Vinschen  <corinna@vinschen.de>
 
 	* Makefile.in: Link ps.exe agains ntdll.dll.

winsup/utils/mount.cc

@@ -1,7 +1,7 @@
 /* mount.cc
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2005,
-   2008 Red Hat, Inc.
+   2008, 2009 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -132,16 +132,19 @@ struct opt
   bool clear;
 } oopts[] =
 {
-  {"binary", MOUNT_BINARY, false},
-  {"text", MOUNT_BINARY, true},
-  {"exec", MOUNT_EXEC, false},
-  {"notexec", MOUNT_NOTEXEC, false},
-  {"cygexec", MOUNT_CYGWIN_EXEC, false},
-  {"nosuid", 0, 0},
   {"acl", MOUNT_NOACL, true},
+  {"auto", 0, false},
+  {"binary", MOUNT_BINARY, false},
+  {"cygexec", MOUNT_CYGWIN_EXEC, false},
+  {"exec", MOUNT_EXEC, false},
   {"noacl", MOUNT_NOACL, false},
-  {"posix=1", MOUNT_NOPOSIX, true},
+  {"nosuid", 0, false},
+  {"notexec", MOUNT_NOTEXEC, false},
+  {"override", MOUNT_OVERRIDE, true},
   {"posix=0", MOUNT_NOPOSIX, false},
+  {"posix=1", MOUNT_NOPOSIX, true},
+  {"text", MOUNT_BINARY, true},
+  {"user", MOUNT_SYSTEM, true}
 };
 
 static void
@@ -366,7 +369,7 @@ mount_entries (void)
   // write fstab entries for normal mount points
   while ((p = getmntent (m)) != NULL)
     // Only list non-cygdrives
-    if (!strstr (p->mnt_opts, ",noumount"))
+    if (!strstr (p->mnt_opts, ",noumount") && !strstr (p->mnt_opts, ",auto"))
       {
 	char fsname[NT_MAX_PATH], dirname[NT_MAX_PATH];
 	printf (format_mnt, convert_spaces (fsname, p->mnt_fsname),

winsup/utils/utils.sgml

@@ -786,16 +786,17 @@ most of the options are duplicates of other mount flags):</para>
 <screen>
   acl        - Use the filesystem's access control lists (ACLs) to
                implement real POSIX permissions (default).
-  noacl      - Ignore ACLs and fake POSIX permissions.
   binary     - Files default to binary mode (default).
-  text       - Files default to CRLF text mode line endings.
-  exec       - Treat all files below mount point as executable.
-  notexec    - Treat all files below mount point as not executable.
   cygexec    - Treat all files below mount point as cygwin executables.
+  exec       - Treat all files below mount point as executable.
+  noacl      - Ignore ACLs and fake POSIX permissions.
   nosuid     - No suid files are allowed (currently unimplemented)
+  notexec    - Treat all files below mount point as not executable.
+  override   - Override immutable mount points.
   posix=0    - Switch off case sensitivity for paths under this mount point.
   posix=1    - Switch on case sensitivity for paths under this mount point
                (default).
+  text       - Files default to CRLF text mode line endings.
 </screen>
 
 <para>For a more complete description of the mount options and the