busybox/libbb/find_mount_point.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
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#include <string.h>
#include "libbb.h"
#include <mntent.h>
/*
* Given a block device, find the mount table entry if that block device
* is mounted.
*
* Given any other file (or directory), find the mount table entry for its
* filesystem.
*/
extern struct mntent *find_mount_point(const char *name, const char *table)
{
struct stat s;
dev_t mountDevice;
FILE *mountTable;
struct mntent *mountEntry;
if (stat(name, &s) != 0)
return 0;
if ((s.st_mode & S_IFMT) == S_IFBLK)
mountDevice = s.st_rdev;
else
mountDevice = s.st_dev;
Major rewrite of mount, umount, losetup. Untangled lots of code, shrunk things down a bit, fixed a number of funky corner cases, added support for several new features (things like mount --move, mount --bind, lazy unounts, automatic detection of loop mounts, and so on). Probably broke several other things, but it's fixable. (Bang on it, tell me what doesn't work for you...) Note: you no longer need to say "-o loop". It does that for you when necessary. Still need to add "user mount" support, which involves making mount suid. Not too hard to do under the new infrastructure, just haven't done it yet... The previous code had the following notes, that belong in the version control comments: - * 3/21/1999 Charles P. Wright <cpwright@cpwright.com> - * searches through fstab when -a is passed - * will try mounting stuff with all fses when passed -t auto - * - * 1999-04-17 Dave Cinege...Rewrote -t auto. Fixed ro mtab. - * - * 1999-10-07 Erik Andersen <andersen@codepoet.org>. - * Rewrite of a lot of code. Removed mtab usage (I plan on - * putting it back as a compile-time option some time), - * major adjustments to option parsing, and some serious - * dieting all around. - * - * 1999-11-06 mtab support is back - andersee - * - * 2000-01-12 Ben Collins <bcollins@debian.org>, Borrowed utils-linux's - * mount to add loop support. - * - * 2000-04-30 Dave Cinege <dcinege@psychosis.com> - * Rewrote fstab while loop and lower mount section. Can now do - * single mounts from fstab. Can override fstab options for single - * mount. Common mount_one call for single mounts and 'all'. Fixed - * mtab updating and stale entries. Removed 'remount' default. - *
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if ((mountTable = setmntent(table ? : bb_path_mtab_file, "r")) == 0)
return 0;
while ((mountEntry = getmntent(mountTable)) != 0) {
if (strcmp(name, mountEntry->mnt_dir) == 0
|| strcmp(name, mountEntry->mnt_fsname) == 0) /* String match. */
break;
if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice) /* Match the device. */
break;
if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice) /* Match the directory's mount point. */
break;
}
endmntent(mountTable);
return mountEntry;
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/