Re: df reports bind mounts creating noisy output

[Paul Eggert]

I've installed the patch along the lines that I proposed in early
October about this issue.  Here it is again, slightly modified to
also treat inaccessible mounts as dummies, since they can happen
with shadowed mount points.

2005-11-25  Paul Eggert  <address@hidden>

        * NEWS: df updates for "none", "proc", inaccessible file systems.
        * doc/coreutils.texi (df invocation): Document treatment of dummy file
        systems better.
        * lib/mountlist.c (ME_DUMMY): "none" and "proc" file systems are dummies
        too.
        * src/df.c (show_point): Ignore inaccessible file systems.
        (usage): -a includes dummy file systems, not size-0 file systems.

Index: NEWS
===================================================================
RCS file: /fetish/cu/NEWS,v
retrieving revision 1.348
diff -p -u -r1.348 NEWS
--- NEWS        22 Nov 2005 16:23:21 -0000      1.348
+++ NEWS        26 Nov 2005 07:47:22 -0000
@@ -9,6 +9,11 @@ GNU coreutils NEWS                      
 
 ** Changes in behavior
 
+  df now considers "none" and "proc" file systems to be dummies and
+  therefore does not normally display them.  Also, inaccessible file
+  systems (which can be caused by shadowed mount points or by chrooted
+  bind mounts) are now dummies, too.
+
   ln now uses different (and we hope clearer) diagnostics when it fails.
   ln -v now acts more like FreeBSD, so it generates output only when
   successful and the output is easier to parse.
Index: doc/coreutils.texi
===================================================================
RCS file: /fetish/cu/doc/coreutils.texi,v
retrieving revision 1.296
diff -p -u -r1.296 coreutils.texi
--- doc/coreutils.texi  16 Nov 2005 22:45:12 -0000      1.296
+++ doc/coreutils.texi  26 Nov 2005 07:47:24 -0000
@@ -8785,11 +8785,9 @@ The program accepts the following option
 @opindex --all
 @cindex automounter file systems
 @cindex ignore file systems
-Include in the listing file systems that have a size of 0 blocks, which
+Include in the listing dummy file systems, which
 are omitted by default.  Such file systems are typically special-purpose
-pseudo-file-systems, such as automounter entries.  Also, file systems of
-type ``ignore'' or ``auto'', supported by some operating systems, are
-only included if this option is specified.
+pseudo-file-systems, such as automounter entries.
 
 @item -B @var{size}
 @itemx address@hidden
Index: lib/mountlist.c
===================================================================
RCS file: /fetish/cu/lib/mountlist.c,v
retrieving revision 1.56
diff -p -u -r1.56 mountlist.c
--- lib/mountlist.c     26 Nov 2005 07:43:50 -0000      1.56
+++ lib/mountlist.c     26 Nov 2005 07:47:24 -0000
@@ -144,6 +144,8 @@ char *strstr ();
 #ifndef ME_DUMMY
 # define ME_DUMMY(Fs_name, Fs_type)            \
     (strcmp (Fs_type, "autofs") == 0           \
+     || strcmp (Fs_type, "none") == 0          \
+     || strcmp (Fs_type, "proc") == 0          \
      || strcmp (Fs_type, "subfs") == 0         \
      /* for Irix 6.5 */                                \
      || strcmp (Fs_type, "ignore") == 0)
Index: src/df.c
===================================================================
RCS file: /fetish/cu/src/df.c,v
retrieving revision 1.169
diff -p -u -r1.169 df.c
--- src/df.c    15 Oct 2005 09:56:03 -0000      1.169
+++ src/df.c    26 Nov 2005 07:47:25 -0000
@@ -615,8 +615,15 @@ show_point (const char *point, const str
              me->me_dev = disk_stats.st_dev;
            else
              {
-               error (0, errno, "%s", quote (me->me_mountdir));
-               exit_status = EXIT_FAILURE;
+               /* Report only I/O errors.  Other errors might be
+                  caused by shadowed mount points, which means POINT
+                  can't possibly be on this file system.  */
+               if (errno == EIO)
+                 {
+                   error (0, errno, "%s", quote (me->me_mountdir));
+                   exit_status = EXIT_FAILURE;
+                 }
+
                /* So we won't try and fail repeatedly. */
                me->me_dev = (dev_t) -2;
              }
@@ -724,7 +731,7 @@ or all file systems by default.\n\
 Mandatory arguments to long options are mandatory for short options too.\n\
 "), stdout);
       fputs (_("\
-  -a, --all             include file systems having 0 blocks\n\
+  -a, --all             include dummy file systems\n\
   -B, --block-size=SIZE use SIZE-byte blocks\n\
   -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 
2G)\n\
   -H, --si              likewise, but use powers of 1000 not 1024\n\