On 12/04/2012 07:18 PM, Jim Meyering wrote:
> Thanks to both of you for keeping this thread moving.
Thanks.
I have moved the change around "a bit" to make the overall
change in df.c smaller. I thought that it would be better
to keep such filtering stuff in get_dev() as all the other
filters, e.g. --local.
A also added some other test cases and another test that
examines rootfs hiding.
Finally, I added some texi documentation.
In the end, that change wasn't that small actually, so I
added a "Co-authored" line to the patch. ;-)
Ondrej (and others): WDYT?
Have a nice day,
Berny
>From b8e311fde1803e900b2f894364922eb9cdd9841c Mon Sep 17 00:00:00 2001
From: Ondrej Oprala <oopr...@redhat.com>
Date: Wed, 5 Dec 2012 01:39:44 +0100
Subject: [PATCH] df: do not print duplicate entries and rootfs by default
* src/df.c (struct devlist): Add new struct for storing already-
examined device numbers.
(devlist_head): Add new store of the above type.
(show_rootfs): Add new global boolean to not skip rootfs.
(dev_examined): Add new function to check if the device has
already been traversed.
(get_dev): Filter out rootfs unless "-t rootfs" or the -a
option is specified. Filter out duplicate entries by calling
the above new dev_examined unless the -a option is specified.
(main): Set the show_rootfs variable appropriately when the -t
option is specified for rootfs. Free device list (guarded by
IF_LINT).
* tests/df/skip-duplicates.sh: Add test to exercise the skipping
of duplicate entries.
* tests/df/skip-rootfs.sh: Add test to exercise the skipping
of the rootfs pseudo file system.
* tests/local.mk: Add the above new tests.
* NEWS (Changes in behavior): Mention the changes.
* doc/coreutils.texi (df invocation): Document df's behavior about
skipping rootfs and duplicate entries.
Co-authored-by: Bernhard Voelker.
---
NEWS | 6 +++
doc/coreutils.texi | 8 ++++
src/df.c | 58 ++++++++++++++++++++++++++++++++
tests/df/skip-duplicates.sh | 77 +++++++++++++++++++++++++++++++++++++++++++
tests/df/skip-rootfs.sh | 46 +++++++++++++++++++++++++
tests/local.mk | 2 +
6 files changed, 197 insertions(+), 0 deletions(-)
create mode 100755 tests/df/skip-duplicates.sh
create mode 100755 tests/df/skip-rootfs.sh
diff --git a/NEWS b/NEWS
index d4aebeb..0694ec5 100644
--- a/NEWS
+++ b/NEWS
@@ -40,6 +40,12 @@ GNU coreutils NEWS -*- outline -*-
field can be in any column. If there is no source column, then df
prints 'total' into the target column.
+ df now properly outputs file system information with bind mounts present on
+ the system by skipping duplicate entries (identified by the device number).
+
+ df now skips the early-boot pseudo file system type "rootfs" unless either the
+ -a option or "-t rootfs" is specified.
+
nl no longer supports the --page-increment option which was deprecated
since coreutils-7.5. Use --line-increment instead.
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 46d3680..21400ad 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -10600,6 +10600,14 @@ Normally the disk space is printed in units of
1024 bytes, but this can be overridden (@pxref{Block size}).
Non-integer quantities are rounded up to the next higher unit.
+For bind mounts and without arguments, @command{df} only outputs the statistics
+for the first occurence of that device in the list of file systems (@var{mtab}),
+i.e., it hides duplicate entries, unless the @option{-a} option is specified.
+
+By default, @command{df} omits the early-boot pseudo file system type
+@samp{rootfs}, unless the @option{-a} option is specified or that file system
+type is explicitly to be included by using the @option{-t} option.
+
@cindex disk device file
@cindex device file, disk
If an argument @var{file} is a disk device file containing a mounted
diff --git a/src/df.c b/src/df.c
index cac26b7..63c8b31 100644
--- a/src/df.c
+++ b/src/df.c
@@ -43,6 +43,17 @@
proper_name ("David MacKenzie"), \
proper_name ("Paul Eggert")
+/* Filled with device numbers of examined file systems to avoid
+ duplicities in output. */
+struct devlist
+{
+ dev_t dev_num;
+ struct devlist *next;
+};
+
+/* Store of already-processed device numbers. */
+static struct devlist *devlist_head;
+
/* If true, show even file systems with zero size or
uninteresting types. */
static bool show_all_fs;
@@ -54,6 +65,12 @@ static bool show_local_fs;
command line argument -- even if it's a dummy (automounter) entry. */
static bool show_listed_fs;
+/* If true, include rootfs in the output. */
+static bool show_rootfs;
+
+/* The literal name of the initial root file system. */
+static char const *ROOTFS = "rootfs";
+
/* Human-readable options for output. */
static int human_output_opts;
@@ -589,6 +606,29 @@ excluded_fstype (const char *fstype)
return false;
}
+/* Check if the device was already examined. */
+
+static bool
+dev_examined (char const *mount_dir, char const *devname)
+{
+ struct stat buf;
+ if (-1 == stat (mount_dir, &buf))
+ return false;
+
+ struct devlist *devlist = devlist_head;
+ for ( ; devlist; devlist = devlist->next)
+ if (devlist->dev_num == buf.st_dev)
+ return true;
+
+ /* Add the device number to the global list devlist. */
+ devlist = xmalloc (sizeof *devlist);
+ devlist->dev_num = buf.st_dev;
+ devlist->next = devlist_head;
+ devlist_head = devlist;
+
+ return false;
+}
+
/* Return true if N is a known integer value. On many file systems,
UINTMAX_MAX represents an unknown value; on AIX, UINTMAX_MAX - 1
represents unknown. Use a rule that works on AIX file systems, and
@@ -758,6 +798,15 @@ get_dev (char const *disk, char const *mount_point,
if (!selected_fstype (fstype) || excluded_fstype (fstype))
return;
+ if (process_all && !show_all_fs && !show_listed_fs)
+ {
+ /* No arguments nor "df -a", then check if df has to ... */
+ if (!show_rootfs && STREQ (disk, ROOTFS))
+ return; /* ... skip rootfs: (unless -trootfs is given. */
+ if (dev_examined (mount_point, disk))
+ return; /* ... skip duplicate entries (bind mounts). */
+ }
+
/* If MOUNT_POINT is NULL, then the file system is not mounted, and this
program reports on the file system that the special file is on.
It would be better to report on the unmounted file system,
@@ -1283,6 +1332,7 @@ main (int argc, char **argv)
/* Accept -F as a synonym for -t for compatibility with Solaris. */
case 't':
add_fs_type (optarg);
+ show_rootfs = selected_fstype (ROOTFS);
break;
case 'v': /* For SysV compatibility. */
@@ -1457,6 +1507,14 @@ main (int argc, char **argv)
}
IF_LINT (free (columns));
+ IF_LINT (
+ while (devlist_head)
+ {
+ struct devlist *devlist = devlist_head->next;
+ free (devlist_head);
+ devlist_head = devlist;
+ }
+ );
exit (exit_status);
}
diff --git a/tests/df/skip-duplicates.sh b/tests/df/skip-duplicates.sh
new file mode 100755
index 0000000..0c5ada2
--- /dev/null
+++ b/tests/df/skip-duplicates.sh
@@ -0,0 +1,77 @@
+#!/bin/sh
+# Test df's behavior when the mount list contains duplicate entries.
+# This test is skipped on systems that lack LD_PRELOAD support; that's fine.
+
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ df
+
+df || skip_ "df fails"
+
+# Simulate an mtab file with two entries of the same device number.
+cat > k.c <<'EOF' || framework_failure_
+#include <stdio.h>
+#include <mntent.h>
+
+struct mntent *getmntent (FILE *fp)
+{
+ /* Prove that LD_PRELOAD works. */
+ static int done = 0;
+ if (!done)
+ {
+ fclose (fopen ("x", "w"));
+ ++done;
+ }
+
+ static struct mntent mntent;
+
+ while (done++ < 3)
+ {
+ mntent.mnt_fsname = "fsname";
+ mntent.mnt_dir = "/";
+ mntent.mnt_type = "-";
+
+ return &mntent;
+ }
+ return NULL;
+}
+EOF
+
+# Then compile/link it:
+gcc --std=gnu99 -shared -fPIC -ldl -O2 k.c -o k.so \
+ || skip_ "getmntent hack does not work on this platform"
+
+# Test if LD_PRELOAD works:
+LD_PRELOAD=./k.so df
+test -f x || skip_ "internal test failure: maybe LD_PRELOAD doesn't work?"
+
+# The fake mtab file should only contain 2 entries, both
+# having the same device number; thus the output should
+# consist of a header and one entry.
+LD_PRELOAD=./k.so df >out || fail=1
+test $(wc -l <out) -eq 2 || fail=1
+
+# Ensure that filtering duplicates does not affect -a processing.
+LD_PRELOAD=./k.so df -a >out || fail=1
+test $(wc -l <out) -eq 3 || fail=1
+
+# Ensure that filtering duplcates does not affect
+# argument processing (now without the fake getmntent()).
+df '.' '.' >out || fail=1
+test $(wc -l <out) -eq 3 || fail=1
+
+Exit $fail
diff --git a/tests/df/skip-rootfs.sh b/tests/df/skip-rootfs.sh
new file mode 100755
index 0000000..9ba2716
--- /dev/null
+++ b/tests/df/skip-rootfs.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+# Test df's behavior for skipping the pseudo "rootfs" file system.
+
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ df
+
+df || skip_ "df fails"
+
+# Verify that rootfs is in mtab (and shown when the -a option is specified).
+df -a >out || fail=1
+grep '^rootfs' out || skip_ "no rootfs in mtab"
+
+# Ensure that rootfs is supressed when no options is specified.
+df >out || fail=1
+grep '^rootfs' out && { fail=1; cat out; }
+
+# Ensure that the rootfs is shown when explicitly specifying "-t rootfs".
+df -t rootfs >out || fail=1
+grep '^rootfs' out || { fail=1; cat out; }
+
+# Ensure that the rootfs is shown when explicitly specifying "-t rootfs",
+# even when the -a option is specified.
+df -t rootfs -a >out || fail=1
+grep '^rootfs' out || { fail=1; cat out; }
+
+# Ensure that the rootfs is omitted in all_fs mode when it is explicitly
+# black-listed.
+df -a -x rootfs >out || fail=1
+grep '^rootfs' out && { fail=1; cat out; }
+
+Exit $fail
diff --git a/tests/local.mk b/tests/local.mk
index 1b0ace4..d5bb6f7 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -457,6 +457,8 @@ all_tests = \
tests/df/unreadable.sh \
tests/df/total-unprocessed.sh \
tests/df/no-mtab-status.sh \
+ tests/df/skip-duplicates.sh \
+ tests/df/skip-rootfs.sh \
tests/dd/direct.sh \
tests/dd/misc.sh \
tests/dd/nocache.sh \
--
1.7.7
