watchdog 5.8 源码

/* $Header: /cvsroot/watchdog/watchdog/src/mount.c,v 1.2 2006/07/31 09:39:23 meskes Exp $ */ /* * A mount(8) for Linux 0.99. * mount.c,v 1.1.1.1 1993/11/18 08:40:51 jrs Exp * * Thu Jul 14 07:32:40 1994: faith@cs.unc.edu added changes from Adam * J. Richter (adam@adam.yggdrasil.com) so that /proc/filesystems is used * if no -t option is given. I modified his patches so that, if * /proc/filesystems is not available, the behavior of mount is the same as * it was previously. * * Wed Sep 14 22:43:00 1994: Mitchum DSouza * (mitch@mrc-applied-psychology.cambridge.ac.uk) added support for mounting * the "loop" device. * * Wed Sep 14 22:55:10 1994: Sander van Malssen (svm@kozmix.hacktic.nl) * added support for remounting readonly file systems readonly. * * Wed Feb 8 09:23:18 1995: Mike Grupenhoff <kashmir@umiacs.UMD.EDU> added * a probe of the superblock for the type before /proc/filesystems is * checked. * * Wed Feb 8 12:27:00 1995: Andries.Brouwer@cwi.nl fixed up error messages. * Sat Jun 3 20:44:38 1995: Patches from Andries.Brouwer@cwi.nl applied. * Tue Sep 26 22:38:20 1995: aeb@cwi.nl, many changes * Fri Feb 23 13:47:00 1996: aeb@cwi.nl, loop device related changes * * Fri Apr 5 01:13:33 1996: quinlan@bucknell.edu, fixed up iso9660 autodetect * * Since then, many changes - aeb. * * Wed Oct 1 23:55:28 1997: Dick Streefland <dick_streefland@tasking.com> * Implemented the "bg", "fg" and "retry" mount options for NFS. * * Tue Aug 4 15:54:31 1998: aeb@cwi.nl: * Open fd 0,1,2 so that printf's do not clobber /etc/mtab or so. * Mangle filenames with embedded spaces. Add ufsmagic. Add locking. * Avoid unnecessary error messages about /proc. * Improve support for noncanonical names in /etc/fstab. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <unistd.h> #include <ctype.h> #include <errno.h> #include <string.h> #include <getopt.h> #include <stdio.h> #include <sys/types.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/wait.h> #include <sys/mount.h> #include "mount_constants.h" #include "sundries.h" #include "wd_mntent.h" #include "fstab.h" #include "lomount.h" #include "loop.h" #include "linux_fs.h" #define PROC_FILESYSTEMS "/proc/filesystems" #define SIZE(a) (sizeof(a)/sizeof(a[0])) #define DO_PS_FIDDLING #ifdef DO_PS_FIDDLING #define PROC_NAME "mount: " static int argc0; static char** argv0; static char** envp0; extern char** environ; #endif /* True for fake mount (-f). */ int fake = 0; /* Don't write a entry in /etc/mtab (-n). */ int mount_nomtab = 0; /* True for explicit readonly (-r). */ int readonly = 0; /* Nonzero for chatty (-v). */ int mount_verbose = 0; /* Nonzero for sloppy (-s). */ int sloppy = 0; /* True for explicit read/write (-w). */ int readwrite = 0; /* True for all mount (-a). */ int all = 0; /* True for fork() during all mount (-F). */ int optfork = 0; /* True if ruid != euid. */ int mount_suid = 0; /* Map from -o and fstab option strings to the flag argument to mount(2). */ struct opt_map { const char *opt; /* option name */ int skip; /* skip in mtab option string */ int inv; /* true if flag value should be inverted */ int mask; /* flag mask value */ }; /* Custom mount options for our own purposes. */ /* We can use the high-order 16 bits, since the mount call has MS_MGC_VAL there. */ #define MS_NOAUTO 0x80000000 #define MS_USER 0x40000000 #define MS_LOOP 0x00010000 /* Options that we keep the mount system call from seeing. */ #define MS_NOSYS (MS_NOAUTO|MS_USER|MS_LOOP) /* Options that we keep from appearing in the options field in the mtab. */ #define MS_NOMTAB (MS_REMOUNT|MS_NOAUTO|MS_USER) /* OPTIONS that we make ordinary users have by default. */ #define MS_SECURE (MS_NOEXEC|MS_NOSUID|MS_NODEV) const struct opt_map opt_map[] = { { "defaults", 0, 0, 0 }, /* default options */ { "ro", 1, 0, MS_RDONLY }, /* read-only */ { "rw", 1, 1, MS_RDONLY }, /* read-write */ { "exec", 0, 1, MS_NOEXEC }, /* permit execution of binaries */ { "noexec", 0, 0, MS_NOEXEC }, /* don't execute binaries */ { "mount_suid", 0, 1, MS_NOSUID }, /* honor mount_suid executables */ { "nomount_suid", 0, 0, MS_NOSUID }, /* don't honor mount_suid executables */ { "dev", 0, 1, MS_NODEV }, /* interpret device files */ { "nodev", 0, 0, MS_NODEV }, /* don't interpret devices */ { "sync", 0, 0, MS_SYNCHRONOUS}, /* synchronous I/O */ { "async", 0, 1, MS_SYNCHRONOUS}, /* asynchronous I/O */ { "remount", 0, 0, MS_REMOUNT}, /* Alter flags of mounted FS */ { "auto", 0, 1, MS_NOAUTO }, /* Can be mounted using -a */ { "noauto", 0, 0, MS_NOAUTO }, /* Can only be mounted explicitly */ { "user", 0, 0, MS_USER }, /* Allow ordinary user to mount */ { "nouser", 0, 1, MS_USER }, /* Forbid ordinary user to mount */ /* add new options here */ #ifdef MS_NOSUB { "sub", 0, 1, MS_NOSUB }, /* allow submounts */ { "nosub", 0, 0, MS_NOSUB }, /* don't allow submounts */ #endif #ifdef MS_SILENT { "quiet", 0, 0, MS_SILENT }, /* be quiet */ { "loud", 0, 1, MS_SILENT }, /* print out messages. */ #endif #ifdef MS_MANDLOCK { "mand", 0, 0, MS_MANDLOCK }, /* Allow mandatory locks on this FS */ { "nomand", 0, 1, MS_MANDLOCK }, /* Forbid mandatory locks on this FS */ #endif { "loop", 1, 0, MS_LOOP }, /* use a loop device */ #ifdef MS_NOATIME { "atime", 0, 1, MS_NOATIME }, /* Update access time */ { "noatime", 0, 0, MS_NOATIME }, /* Do not update access time */ #endif #ifdef MS_NODIRATIME { "diratime", 0, 1, MS_NODIRATIME }, /* Update dir access times */ { "nodiratime", 0, 0, MS_NODIRATIME },/* Do not update dir access times */ #endif { NULL, 0, 0, 0 } }; char *opt_loopdev, *opt_vfstype, *opt_offset, *opt_encryption; struct string_opt_map { char *tag; int skip; char **valptr; } string_opt_map[] = { { "loop=", 0, &opt_loopdev }, { "vfs=", 1, &opt_vfstype }, { "offset=", 0, &opt_offset }, { "encryption=", 0, &opt_encryption }, { NULL, 0, NULL } }; static void clear_string_opts(void) { struct string_opt_map *m; for (m = &string_opt_map[0]; m->tag; m++) *(m->valptr) = NULL; } static int parse_string_opt(char *s) { struct string_opt_map *m; int lth; for (m = &string_opt_map[0]; m->tag; m++) { lth = strlen(m->tag); if (!strncmp(s, m->tag, lth)) { *(m->valptr) = xstrdup(s + lth); return 1; } } return 0; } int mount_mount_quiet=0; /* Report on a single mount. */ static void print_one (const struct mntentchn *mc) { if (mount_mount_quiet) return; printf ("%s on %s", mc->mnt_fsname, mc->mnt_dir); if (mc->mnt_type != NULL && *(mc->mnt_type) != '\0') printf (" type %s", mc->mnt_type); if (mc->mnt_opts != NULL) printf (" (%s)", mc->mnt_opts); printf ("\n"); } /* Report on everything in mtab (of the specified types if any). */ static int print_all (string_list types) { struct mntentchn *mc; for (mc = mtab_head()->nxt; mc; mc = mc->nxt) { if (matching_type (mc->mnt_type, types)) print_one (mc); } exit (0); } /* Look for OPT in opt_map table and return mask value. If OPT isn't found, tack it onto extra_opts (which is non-NULL). */ static inline void parse_opt (const char *opt, int *mask, char *extra_opts) { const struct opt_map *om; for (om = opt_map; om->opt != NULL; om++) if (streq (opt, om->opt)) { if (om->inv) *mask &= ~om->mask; else *mask |= om->mask; if (om->mask == MS_USER) *mask |= MS_SECURE; #ifdef MS_SILENT if (om->mask == MS_SILENT && om->inv) { mount_mount_quiet = 1; mount_verbose = 0; } #endif return; } if (*extra_opts) strcat(extra_opts, ","); strcat(extra_opts, opt); } /* Take -o options list and compute 4th and 5th args to mount(2). flags gets the standard options and extra_opts anything we don't recognize. */ static void parse_opts (char *opts, int *flags, char **extra_opts) { char *o