+/* vi: set sw=4 ts=4: */
/*
* Mini umount implementation for busybox
*
#include <fstab.h>
#include <errno.h>
-static const char umount_usage[] =
-"Usage: umount [flags] filesystem|directory\n\n"
-"Flags:\n"
-"\t-a:\tUnmount all file systems"
+
+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"
+ " in /etc/mtab\n\t-n:\tDon't erase /etc/mtab entries\n"
#else
-"\n"
+ "\n"
+#endif
+#ifdef BB_FEATURE_REMOUNT
+ "\t-r:\tTry to remount devices as read-only if mount is busy\n"
+#endif
+#if defined BB_FEATURE_MOUNT_LOOP
+ "\t-f:\tDo not free loop device (if a loop device has been used)\n"
#endif
;
+struct _mtab_entry_t {
+ char *device;
+ char *mountpt;
+ struct _mtab_entry_t *next;
+};
+
+static struct _mtab_entry_t *mtab_cache = NULL;
+
+
+#if defined BB_FEATURE_MOUNT_LOOP
+static int freeLoop = TRUE;
+#endif
static int useMtab = TRUE;
static int umountAll = FALSE;
-extern const char mtab_file[]; /* Defined in utility.c */
+#if defined BB_FEATURE_REMOUNT
+static int doRemount = FALSE;
+#endif
+extern const char mtab_file[]; /* Defined in utility.c */
-#if ! defined BB_MTAB
-#define do_umount( blockDevice, useMtab) umount( blockDevice)
-#else
-static int
-do_umount(const char* name, int useMtab)
+
+
+/* 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)
{
- int status = umount(name);
-
- if ( status == 0 ) {
- if ( useMtab==TRUE )
- erase_mtab(name);
- return 0;
- }
- else
- return( status);
+ 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 = 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);
}
+
+char *mtab_getinfo(const char *match, const char which)
+{
+ 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;
+ }
#endif
+ return cur->device;
+ }
+ }
+ cur = cur->next;
+ }
+ return NULL;
+}
+
+char *mtab_first(void **iter)
+{
+ struct _mtab_entry_t *mtab_iter;
+
+ if (!iter)
+ return NULL;
+ mtab_iter = mtab_cache;
+ *iter = (void *) mtab_iter;
+ return mtab_next(iter);
+}
-static int
-umount_all(int useMtab)
+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;
+}
+
+void mtab_free(void)
+{
+ 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;
+ }
+}
+
+static int do_umount(const char *name, int useMtab)
{
int status;
- struct mntent *m;
- FILE *mountTable;
-
- if ((mountTable = setmntent (mtab_file, "r"))) {
- while ((m = getmntent (mountTable)) != 0) {
- char *blockDevice = m->mnt_fsname;
-#if ! defined BB_MTAB
- if (strcmp (blockDevice, "/dev/root") == 0) {
- struct fstab* fstabItem;
- fstabItem = getfsfile ("/");
- if (fstabItem != NULL) {
- blockDevice = fstabItem->fs_spec;
- }
+ 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_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);
}
+ }
#endif
- /* Don't umount /proc when doing umount -a */
- if (strcmp (blockDevice, "proc") == 0)
- continue;
-
- status=do_umount (m->mnt_dir, useMtab);
- if (status!=0) {
- /* Don't bother retrying the umount on busy devices */
- if (errno==EBUSY) {
- perror(m->mnt_dir);
+ if (status == 0) {
+#if defined BB_MTAB
+ if (useMtab == TRUE)
+ erase_mtab(name);
+#endif
+ return (TRUE);
+ }
+ return (FALSE);
+}
+
+static int umount_all(int useMtab)
+{
+ int status = TRUE;
+ char *mountpt;
+ void *iter;
+
+ for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
+ /* Never umount /proc on a umount -a */
+ if (strstr(mountpt, "proc")!= NULL)
continue;
- }
- status=do_umount (blockDevice, useMtab);
- if (status!=0) {
- printf ("Couldn't umount %s on %s (type %s): %s\n",
- blockDevice, m->mnt_dir, m->mnt_type, strerror(errno));
- }
+ 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));
+ }
}
- }
- endmntent (mountTable);
- }
- return( TRUE);
+ }
+ return (status);
}
-extern int
-umount_main(int argc, char** argv)
+extern int umount_main(int argc, char **argv)
{
+ if (argc < 2) {
+ usage(umount_usage);
+ }
- if (argc < 2) {
- usage( umount_usage);
- }
-
- /* Parse any options */
- while (--argc > 0 && **(++argv) == '-') {
- while (*++(*argv)) switch (**argv) {
- case 'a':
- umountAll = TRUE;
- break;
+ /* Parse any options */
+ while (--argc > 0 && **(++argv) == '-') {
+ while (*++(*argv))
+ switch (**argv) {
+ case 'a':
+ umountAll = TRUE;
+ break;
+#if defined BB_FEATURE_MOUNT_LOOP
+ case 'f':
+ freeLoop = FALSE;
+ break;
+#endif
#ifdef BB_MTAB
- case 'n':
- useMtab = FALSE;
- break;
+ case 'n':
+ useMtab = FALSE;
+ break;
+#endif
+#ifdef BB_FEATURE_REMOUNT
+ case 'r':
+ doRemount = TRUE;
+ break;
#endif
- default:
- usage( umount_usage);
+ 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);
}
- }
-
-
- if(umountAll==TRUE) {
- exit(umount_all(useMtab));
- }
- if ( do_umount(*argv,useMtab) == 0 )
- exit (TRUE);
- else {
- perror("umount");
- exit( FALSE);
- }
}
projects / oweals / busybox.git / blobdiff