copy_file_chunk uses streams now.
[oweals/busybox.git] / umount.c
index b65caf76e21eb049c9e59c463bbabc4320ca1c1a..3e23b9705edf3e660f277fca16eadf945d496ded 100644 (file)
--- a/umount.c
+++ b/umount.c
@@ -1,8 +1,9 @@
+/* vi: set sw=4 ts=4: */
 /*
  * Mini umount implementation for busybox
  *
  *
- * Copyright (C) 1999 by Lineo, inc.
+ * Copyright (C) 1999,2000,2001 by Lineo, inc.
  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
  *
  * This program is free software; you can redistribute it and/or modify
  *
  */
 
-#include "internal.h"
 #include <stdio.h>
-#include <sys/mount.h>
 #include <mntent.h>
-#include <fstab.h>
 #include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include "busybox.h"
 
-static const char umount_usage[] = 
-"umount [flags] filesystem|directory\n\n"
-"Flags:\n"
-"\t-a:\tUnmount all file systems"
-#ifdef BB_MTAB
-" in /etc/mtab\n\t-n:\tDon't erase /etc/mtab entries\n"
-#else
-"\n"
-#endif
-#ifdef BB_FEATURE_REMOUNT
-"\t-r:\tTry to remount devices as read-only if mount is busy\n"
-#endif
-;
+
+static const int MNT_FORCE = 1;
+static const int MS_MGC_VAL = 0xc0ed0000; /* Magic number indicatng "new" flags */
+static const int MS_REMOUNT = 32;      /* Alter flags of a mounted FS.  */
+static const int MS_RDONLY = 1;        /* Mount read-only.  */
+
+extern int mount (__const char *__special_file, __const char *__dir,
+                       __const char *__fstype, unsigned long int __rwflag,
+                       __const void *__data);
+extern int umount (__const char *__special_file);
+extern int umount2 (__const char *__special_file, int __flags);
 
 struct _mtab_entry_t {
-  char *device;
-  char *mountpt;
-  struct _mtab_entry_t *next;
+       char *device;
+       char *mountpt;
+       struct _mtab_entry_t *next;
 };
 
 static struct _mtab_entry_t *mtab_cache = NULL;
 
 
 
+#if defined BB_FEATURE_MOUNT_FORCE
+static int doForce = FALSE;
+#endif
+#if defined BB_FEATURE_MOUNT_LOOP
+static int freeLoop = TRUE;
+#endif
+#if defined BB_FEATURE_MTAB_SUPPORT
 static int useMtab = TRUE;
+#endif
 static int umountAll = FALSE;
 static int doRemount = FALSE;
-extern const char mtab_file[]; /* Defined in utility.c */
+extern const char mtab_file[]; /* Defined in utility.c */
 
-#define MIN(x,y) (x > y ? x : y)
 
-static int 
-do_umount(const char* name, int useMtab)
-{
-    int status;
-    char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
 
-    if (blockDevice && strcmp(blockDevice, name) == 0)
-        name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
+/* These functions are here because the getmntent functions do not appear
+ * to be re-entrant, which leads to all sorts of problems when we try to
+ * use them recursively - randolph
+ *
+ * TODO: Perhaps switch to using Glibc's getmntent_r
+ *        -Erik
+ */
+void mtab_read(void)
+{
+       struct _mtab_entry_t *entry = NULL;
+       struct mntent *e;
+       FILE *fp;
 
-    status = umount(name);
+       if (mtab_cache != NULL)
+               return;
 
-#if defined BB_FEATURE_MOUNT_LOOP
-    if (blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
-       /* this was a loop device, delete it */
-       del_loop(blockDevice);
-#endif
-#if defined BB_FEATURE_REMOUNT
-    if ( status != 0 && doRemount == TRUE && errno == EBUSY ) {
-        status = mount(blockDevice, name, NULL, 
-                       MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
-       if (status == 0) {
-           fprintf(stderr, "umount: %s busy - remounted read-only\n", 
-                    blockDevice);
-           /* TODO: update mtab if BB_MTAB is defined */
-       } else {
-           fprintf(stderr, "umount: Cannot remount %s read-only\n",
-                    blockDevice);
+       if ((fp = setmntent(mtab_file, "r")) == NULL) {
+               error_msg("Cannot open %s", mtab_file);
+               return;
        }
-    }
-#endif
-    if ( status == 0 ) {
-#if defined BB_MTAB
-       if ( useMtab==TRUE )
-           erase_mtab(name);
-#endif
-       return( TRUE);
-    }
-    return(FALSE);
+       while ((e = getmntent(fp))) {
+               entry = xmalloc(sizeof(struct _mtab_entry_t));
+               entry->device = strdup(e->mnt_fsname);
+               entry->mountpt = strdup(e->mnt_dir);
+               entry->next = mtab_cache;
+               mtab_cache = entry;
+       }
+       endmntent(fp);
 }
 
-static int
-umount_all(int useMtab)
+char *mtab_getinfo(const char *match, const char which)
 {
-       int status = TRUE;
-       char *mountpt;
-       void *iter;
+       struct _mtab_entry_t *cur = mtab_cache;
 
-       for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
-            status=do_umount (mountpt, useMtab);
-            if (status != 0) {
-                /* Don't bother retrying the umount on busy devices */
-               if (errno == EBUSY) {
-                   perror(mountpt);
-                  continue;
-               }
-               status = do_umount (mountpt, useMtab);
-               if (status != 0) {
-                    printf ("Couldn't umount %s on %s: %s\n", 
-                        mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE), strerror(errno));
+       while (cur) {
+               if (strcmp(cur->mountpt, match) == 0 ||
+                       strcmp(cur->device, match) == 0) {
+                       if (which == MTAB_GETMOUNTPT) {
+                               return cur->mountpt;
+                       } else {
+#if !defined BB_FEATURE_MTAB_SUPPORT
+                               if (strcmp(cur->device, "/dev/root") == 0) {
+                                       /* Adjusts device to be the real root device,
+                                        * or leaves device alone if it can't find it */
+                                       find_real_root_device_name( cur->device);
+                                       return ( cur->device);
+                               }
+#endif
+                               return cur->device;
+                       }
                }
-            }
-        }
-        return (status);
+               cur = cur->next;
+       }
+       return NULL;
 }
 
-extern int
-umount_main(int argc, char** argv)
+char *mtab_first(void **iter)
 {
-    if (argc < 2) {
-       usage( umount_usage); 
-    }
-
-    /* Parse any options */
-    while (--argc > 0 && **(++argv) == '-') {
-       while (*++(*argv)) switch (**argv) {
-           case 'a':
-               umountAll = TRUE;
-               break;
-#ifdef BB_MTAB
-           case 'n':
-               useMtab = FALSE;
-               break;
-#endif
-#ifdef BB_FEATURE_REMOUNT
-           case 'r':
-               doRemount = TRUE;
-               break;
-#endif
-           default:
-               usage( umount_usage);
-       }
-    }
-
-    mtab_read();
-    if (umountAll==TRUE) {
-       exit(umount_all(useMtab));
-    }
-    if ( do_umount(*argv,useMtab) == 0 )
-       exit (TRUE);
-    else {
-       perror("umount");
-       exit(FALSE);
-    }
+       struct _mtab_entry_t *mtab_iter;
+
+       if (!iter)
+               return NULL;
+       mtab_iter = mtab_cache;
+       *iter = (void *) mtab_iter;
+       return mtab_next(iter);
 }
 
+char *mtab_next(void **iter)
+{
+       char *mp;
 
+       if (iter == NULL || *iter == NULL)
+               return NULL;
+       mp = ((struct _mtab_entry_t *) (*iter))->mountpt;
+       *iter = (void *) ((struct _mtab_entry_t *) (*iter))->next;
+       return mp;
+}
 
-/* These functions are here because the getmntent functions do not appear
- * to be re-entrant, which leads to all sorts of problems when we try to
- * use them recursively - randolph
- */
-void mtab_read(void)
+/* Don't bother to clean up, since exit() does that 
+ * automagically, so we can save a few bytes */
+#ifdef BB_FEATURE_CLEAN_UP
+void mtab_free(void)
 {
-    struct _mtab_entry_t *entry = NULL;
-    struct mntent *e;
-    FILE *fp;
-  
-    if (mtab_cache != NULL) return;
-    if ((fp = setmntent(mtab_file, "r")) == NULL) {
-        fprintf(stderr, "Cannot open %s\n", mtab_file);
-       return;
-    }
-    while ((e = getmntent(fp))) {
-        entry = malloc(sizeof(struct _mtab_entry_t));
-       entry->device = strdup(e->mnt_fsname);
-       entry->mountpt = strdup(e->mnt_dir);
-       entry->next = mtab_cache;
-       mtab_cache = entry;
-    }
-    endmntent(fp);
+       struct _mtab_entry_t *this, *next;
+
+       this = mtab_cache;
+       while (this) {
+               next = this->next;
+               if (this->device)
+                       free(this->device);
+               if (this->mountpt)
+                       free(this->mountpt);
+               free(this);
+               this = next;
+       }
 }
+#endif
 
-char *mtab_getinfo(const char *match, const char which)
+static int do_umount(const char *name)
 {
-    struct _mtab_entry_t *cur = mtab_cache;
-    while (cur) {
-        if (strcmp(cur->mountpt, match) == 0 ||
-           strcmp(cur->device, match) == 0) {
-           if (which == MTAB_GETMOUNTPT) {
-               return cur->mountpt;
-           } else {
-#if !defined BB_MTAB
-                if (strcmp(cur->device, "/dev/root") == 0) {
-                    struct fstab* fstabItem;
-                   fstabItem = getfsfile ("/");
-                   if (fstabItem != NULL) return fstabItem->fs_spec;
-               }
+       int status;
+       char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
+
+       if (blockDevice && strcmp(blockDevice, name) == 0)
+               name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
+
+       status = umount(name);
+
+#if defined BB_FEATURE_MOUNT_LOOP
+       if (freeLoop == TRUE && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
+               /* this was a loop device, delete it */
+               del_loop(blockDevice);
+#endif
+#if defined BB_FEATURE_MOUNT_FORCE
+       if (status != 0 && doForce == TRUE) {
+               status = umount2(blockDevice, MNT_FORCE);
+               if (status != 0) {
+                       error_msg_and_die("forced umount of %s failed!", blockDevice);
+               }
+       }
 #endif
-               return cur->device;  
-           }
+       if (status != 0 && doRemount == TRUE && errno == EBUSY) {
+               status = mount(blockDevice, name, NULL,
+                                          MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
+               if (status == 0) {
+                       error_msg("%s busy - remounted read-only", blockDevice);
+               } else {
+                       error_msg("Cannot remount %s read-only", blockDevice);
+               }
        }
-        cur = cur->next;
-    }
-    return NULL;
+       if (status == 0) {
+#if defined BB_FEATURE_MTAB_SUPPORT
+               if (useMtab == TRUE)
+                       erase_mtab(name);
+#endif
+               return (TRUE);
+       }
+       return (FALSE);
 }
 
-char *mtab_first(void **iter)
+static int umount_all(void)
 {
-    struct _mtab_entry_t *mtab_iter;
-    if (!iter) return NULL;
-    mtab_iter = mtab_cache;
-    *iter = (void *)mtab_iter;
-    return mtab_next(iter);
-}
+       int status = TRUE;
+       char *mountpt;
+       void *iter;
 
-char *mtab_next(void **iter)
-{
-    char *mp;
-    if (iter == NULL || *iter == NULL) return NULL;
-    mp = ((struct _mtab_entry_t *)(*iter))->mountpt;
-    *iter = (void *)((struct _mtab_entry_t *)(*iter))->next;
-    return mp;
+       for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
+               /* Never umount /proc on a umount -a */
+               if (strstr(mountpt, "proc")!= NULL)
+                       continue;
+               if (!do_umount(mountpt)) {
+                       /* Don't bother retrying the umount on busy devices */
+                       if (errno == EBUSY) {
+                               perror_msg("%s", mountpt);
+                               status = FALSE;
+                               continue;
+                       }
+                       if (!do_umount(mountpt)) {
+                               printf("Couldn't umount %s on %s: %s\n",
+                                          mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE),
+                                          strerror(errno));
+                               status = FALSE;
+                       }
+               }
+       }
+       return (status);
 }
 
-void mtab_free(void)
+extern int umount_main(int argc, char **argv)
 {
-    struct _mtab_entry_t *this, *next;
-
-    this = mtab_cache;
-    while (this) {
-      next = this->next;
-      if (this->device) free(this->device);
-      if (this->mountpt) free(this->mountpt);
-      free(this);
-      this = next;
-    }
+       if (argc < 2) {
+               show_usage();
+       }
+#ifdef BB_FEATURE_CLEAN_UP
+       atexit(mtab_free);
+#endif
+
+       /* Parse any options */
+       while (--argc > 0 && **(++argv) == '-') {
+               while (*++(*argv))
+                       switch (**argv) {
+                       case 'a':
+                               umountAll = TRUE;
+                               break;
+#if defined BB_FEATURE_MOUNT_LOOP
+                       case 'l':
+                               freeLoop = FALSE;
+                               break;
+#endif
+#ifdef BB_FEATURE_MTAB_SUPPORT
+                       case 'n':
+                               useMtab = FALSE;
+                               break;
+#endif
+#ifdef BB_FEATURE_MOUNT_FORCE
+                       case 'f':
+                               doForce = TRUE;
+                               break;
+#endif
+                       case 'r':
+                               doRemount = TRUE;
+                               break;
+                       case 'v':
+                               break; /* ignore -v */
+                       default:
+                               show_usage();
+                       }
+       }
+
+       mtab_read();
+       if (umountAll == TRUE) {
+               if (umount_all() == TRUE)
+                       return EXIT_SUCCESS;
+               else
+                       return EXIT_FAILURE;
+       }
+       if (do_umount(*argv) == TRUE)
+               return EXIT_SUCCESS;
+       perror_msg_and_die("%s", *argv);
 }