chiark / gitweb /
umount: ignore missing /proc/swaps
[elogind.git] / src / umount.c
index 44bed61..95efa82 100644 (file)
@@ -26,6 +26,7 @@
 #include <sys/swap.h>
 #include <unistd.h>
 #include <linux/loop.h>
+#include <linux/dm-ioctl.h>
 #include <libudev.h>
 
 #include "list.h"
 
 typedef struct MountPoint {
         char *path;
+        dev_t devnum;
+        bool skip_ro;
         LIST_FIELDS (struct MountPoint, mount_point);
 } MountPoint;
 
-/* Takes over possession of path */
-static MountPoint *mount_point_alloc(char *path) {
-        MountPoint *mp;
+static void mount_point_free(MountPoint **head, MountPoint *m) {
+        assert(head);
+        assert(m);
 
-        if (!(mp = new(MountPoint, 1)))
-                return NULL;
+        LIST_REMOVE(MountPoint, mount_point, *head, m);
 
-        mp->path = path;
-        return mp;
+        free(m->path);
+        free(m);
 }
 
-static void mount_point_remove_and_free(MountPoint *mount_point, MountPoint **mount_point_list_head) {
-        LIST_REMOVE(MountPoint, mount_point, *mount_point_list_head, mount_point);
+static void mount_points_list_free(MountPoint **head) {
+        assert(head);
 
-        free(mount_point->path);
-        free(mount_point);
+        while (*head)
+                mount_point_free(head, *head);
 }
 
-static void mount_points_list_free(MountPoint **mount_point_list_head) {
-        while (*mount_point_list_head)
-                mount_point_remove_and_free(*mount_point_list_head, mount_point_list_head);
-}
-
-static int mount_points_list_get(MountPoint **mount_point_list_head) {
+static int mount_points_list_get(MountPoint **head) {
         FILE *proc_self_mountinfo;
         char *path, *p;
         unsigned int i;
         int r;
 
+        assert(head);
+
         if (!(proc_self_mountinfo = fopen("/proc/self/mountinfo", "re")))
                 return -errno;
 
         for (i = 1;; i++) {
                 int k;
-                MountPoint *mp;
+                MountPoint *m;
+                char *root;
+                bool skip_ro;
 
                 path = p = NULL;
 
@@ -80,7 +81,7 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
                                 "%*s "       /* (1) mount id */
                                 "%*s "       /* (2) parent id */
                                 "%*s "       /* (3) major:minor */
-                                "%*s "       /* (4) root */
+                                "%ms "       /* (4) root */
                                 "%ms "       /* (5) mount point */
                                 "%*s"        /* (6) mount options */
                                 "%*[^-]"     /* (7) optional fields */
@@ -89,7 +90,8 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
                                 "%*s"        /* (10) mount source */
                                 "%*s"        /* (11) mount options 2 */
                                 "%*[^\n]",   /* some rubbish at the end */
-                                &path)) != 1) {
+                                &root,
+                                &path)) != 2) {
                         if (k == EOF)
                                 break;
 
@@ -99,6 +101,11 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
                         continue;
                 }
 
+                /* If we encounter a bind mount, don't try to remount
+                 * the source dir too early */
+                skip_ro = !streq(root, "/");
+                free(root);
+
                 p = cunescape(path);
                 free(path);
 
@@ -107,18 +114,20 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
                         goto finish;
                 }
 
-                if (mount_point_is_api(p)) {
+                if (mount_point_is_api(p) || mount_point_ignore(p)) {
                         free(p);
                         continue;
                 }
 
-                if (!(mp = mount_point_alloc(p))) {
+                if (!(m = new0(MountPoint, 1))) {
                         free(p);
                         r = -ENOMEM;
                         goto finish;
                 }
 
-                LIST_PREPEND(MountPoint, mount_point, *mount_point_list_head, mp);
+                m->path = p;
+                m->skip_ro = skip_ro;
+                LIST_PREPEND(MountPoint, mount_point, *head, m);
         }
 
         r = 0;
@@ -129,13 +138,15 @@ finish:
         return r;
 }
 
-static int swap_list_get(MountPoint **swap_list_head) {
+static int swap_list_get(MountPoint **head) {
         FILE *proc_swaps;
         unsigned int i;
         int r;
 
+        assert(head);
+
         if (!(proc_swaps = fopen("/proc/swaps", "re")))
-                return -errno;
+                return (errno == ENOENT) ? 0 : -errno;
 
         (void) fscanf(proc_swaps, "%*s %*s %*s %*s %*s\n");
 
@@ -174,14 +185,14 @@ static int swap_list_get(MountPoint **swap_list_head) {
                         goto finish;
                 }
 
-                swap = mount_point_alloc(d);
-                if (!swap) {
+                if (!(swap = new0(MountPoint, 1))) {
                         free(d);
                         r = -ENOMEM;
                         goto finish;
                 }
 
-                LIST_PREPEND(MountPoint, mount_point, *swap_list_head, swap);
+                swap->path = d;
+                LIST_PREPEND(MountPoint, mount_point, *head, swap);
         }
 
         r = 0;
@@ -192,12 +203,14 @@ finish:
         return r;
 }
 
-static int loopback_list_get(MountPoint **loopback_list_head) {
+static int loopback_list_get(MountPoint **head) {
         int r;
         struct udev *udev;
         struct udev_enumerate *e = NULL;
         struct udev_list_entry *item = NULL, *first = NULL;
 
+        assert(head);
+
         if (!(udev = udev_new())) {
                 r = -ENOMEM;
                 goto finish;
@@ -208,12 +221,84 @@ static int loopback_list_get(MountPoint **loopback_list_head) {
                 goto finish;
         }
 
-        if (udev_enumerate_add_match_subsystem(e, "block") < 0) {
+        if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+            udev_enumerate_add_match_sysname(e, "loop*") < 0) {
                 r = -EIO;
                 goto finish;
         }
 
-        if (udev_enumerate_add_match_sysname(e, "loop*") < 0) {
+        if (udev_enumerate_scan_devices(e) < 0) {
+                r = -EIO;
+                goto finish;
+        }
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                MountPoint *lb;
+                struct udev_device *d;
+                char *loop;
+                const char *dn;
+
+                if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(dn = udev_device_get_devnode(d))) {
+                        udev_device_unref(d);
+                        continue;
+                }
+
+                loop = strdup(dn);
+                udev_device_unref(d);
+
+                if (!loop) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(lb = new0(MountPoint, 1))) {
+                        free(loop);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                lb->path = loop;
+                LIST_PREPEND(MountPoint, mount_point, *head, lb);
+        }
+
+        r = 0;
+
+finish:
+        if (e)
+                udev_enumerate_unref(e);
+
+        if (udev)
+                udev_unref(udev);
+
+        return r;
+}
+
+static int dm_list_get(MountPoint **head) {
+        int r;
+        struct udev *udev;
+        struct udev_enumerate *e = NULL;
+        struct udev_list_entry *item = NULL, *first = NULL;
+
+        assert(head);
+
+        if (!(udev = udev_new())) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (!(e = udev_enumerate_new(udev))) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+            udev_enumerate_add_match_sysname(e, "dm-*") < 0) {
                 r = -EIO;
                 goto finish;
         }
@@ -226,9 +311,10 @@ static int loopback_list_get(MountPoint **loopback_list_head) {
         first = udev_enumerate_get_list_entry(e);
 
         udev_list_entry_foreach(item, first) {
-                MountPoint *lb;
+                MountPoint *m;
                 struct udev_device *d;
-                char *loop;
+                dev_t devnum;
+                char *node;
                 const char *dn;
 
                 if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
@@ -236,24 +322,31 @@ static int loopback_list_get(MountPoint **loopback_list_head) {
                         goto finish;
                 }
 
-                if ((dn = udev_device_get_devnode(d))) {
-                        loop = strdup(dn);
-                        udev_device_unref(d);
+                devnum = udev_device_get_devnum(d);
+                dn = udev_device_get_devnode(d);
 
-                        if (!loop) {
-                                r = -ENOMEM;
-                                goto finish;
-                        }
-                } else
+                if (major(devnum) == 0 || !dn) {
                         udev_device_unref(d);
+                        continue;
+                }
 
-                if (!(lb = mount_point_alloc(loop))) {
-                        free(loop);
+                node = strdup(dn);
+                udev_device_unref(d);
+
+                if (!node) {
                         r = -ENOMEM;
                         goto finish;
                 }
 
-                LIST_PREPEND(MountPoint, mount_point, *loopback_list_head, lb);
+                if (!(m = new(MountPoint, 1))) {
+                        free(node);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                m->path = node;
+                m->devnum = devnum;
+                LIST_PREPEND(MountPoint, mount_point, *head, m);
         }
 
         r = 0;
@@ -272,85 +365,191 @@ static int delete_loopback(const char *device) {
         int fd, r;
 
         if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0)
-                return -errno;
+                return errno == ENOENT ? 0 : -errno;
 
         r = ioctl(fd, LOOP_CLR_FD, 0);
         close_nointr_nofail(fd);
 
+        if (r >= 0)
+                return 1;
+
         /* ENXIO: not bound, so no error */
-        return (r >= 0 || errno == ENXIO) ? 0 : -errno;
+        if (errno == ENXIO)
+                return 0;
+
+        return -errno;
+}
+
+static int delete_dm(dev_t devnum) {
+        int fd, r;
+        struct dm_ioctl dm;
+
+        assert(major(devnum) != 0);
+
+        if ((fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC)) < 0)
+                return -errno;
+
+        zero(dm);
+        dm.version[0] = DM_VERSION_MAJOR;
+        dm.version[1] = DM_VERSION_MINOR;
+        dm.version[2] = DM_VERSION_PATCHLEVEL;
+
+        dm.data_size = sizeof(dm);
+        dm.dev = devnum;
+
+        r = ioctl(fd, DM_DEV_REMOVE, &dm);
+        close_nointr_nofail(fd);
+
+        return r >= 0 ? 0 : -errno;
 }
 
-static int mount_points_list_umount(MountPoint **mount_point_list_head) {
-        MountPoint *mp, *mp_next;
-        int failed = 0;
+static int mount_points_list_umount(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
 
-        LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
-                if (streq(mp->path, "/"))
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                if (streq(m->path, "/")) {
+                        n_failed++;
                         continue;
+                }
 
                 /* Trying to umount. Forcing to umount if busy (only for NFS mounts) */
-                if (umount2(mp->path, MNT_FORCE) == 0)
-                        mount_point_remove_and_free(mp, mount_point_list_head);
-                else {
-                        log_warning("Could not unmount %s: %m", mp->path);
-                        failed++;
+                if (umount2(m->path, MNT_FORCE) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not unmount %s: %m", m->path);
+                        n_failed++;
                 }
         }
 
-        return failed;
+        return n_failed;
 }
 
-static int mount_points_list_remount_read_only(MountPoint **mount_point_list_head) {
-        MountPoint *mp, *mp_next;
-        int failed = 0;
+static int mount_points_list_remount_read_only(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+
+                if (m->skip_ro) {
+                        n_failed++;
+                        continue;
+                }
 
-        LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
                 /* Trying to remount read-only */
-                if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0)
-                        mount_point_remove_and_free(mp, mount_point_list_head);
-                else {
-                        log_warning("Could not remount as read-only %s: %m", mp->path);
-                        failed++;
+                if (mount(NULL, m->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not remount as read-only %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+static int swap_points_list_off(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                if (swapoff(m->path) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not deactivate swap %s: %m", m->path);
+                        n_failed++;
                 }
         }
 
-        return failed;
+        return n_failed;
 }
 
-static int swap_points_list_off(MountPoint **swap_list_head) {
-        MountPoint *swap, *swap_next;
-        int failed = 0;
+static int loopback_points_list_detach(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0, k;
+        struct stat root_st;
+
+        assert(head);
+
+        k = lstat("/", &root_st);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                int r;
+                struct stat loopback_st;
 
-        LIST_FOREACH_SAFE(mount_point, swap, swap_next, *swap_list_head) {
-                if (swapoff(swap->path) == 0)
-                        mount_point_remove_and_free(swap, swap_list_head);
-                else {
-                        log_warning("Could not deactivate swap %s: %m", swap->path);
-                        failed++;
+                if (k >= 0 &&
+                    major(root_st.st_dev) != 0 &&
+                    lstat(m->path, &loopback_st) >= 0 &&
+                    root_st.st_dev == loopback_st.st_rdev) {
+                        n_failed ++;
+                        continue;
+                }
+
+                if ((r = delete_loopback(m->path)) >= 0) {
+
+                        if (r > 0 && changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not delete loopback %s: %m", m->path);
+                        n_failed++;
                 }
         }
 
-        return failed;
+        return n_failed;
 }
 
-static int loopback_points_list_detach(MountPoint **loopback_list_head) {
-        MountPoint *loopback, *loopback_next;
-        int failed = 0;
+static int dm_points_list_detach(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0, k;
+        struct stat root_st;
+
+        assert(head);
+
+        k = lstat("/", &root_st);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                int r;
 
-        LIST_FOREACH_SAFE(mount_point, loopback, loopback_next, *loopback_list_head) {
-                if (delete_loopback(loopback->path) == 0)
-                        mount_point_remove_and_free(loopback, loopback_list_head);
-                else {
-                        log_warning("Could not delete loopback %s: %m", loopback->path);
-                        failed++;
+                if (k >= 0 &&
+                    major(root_st.st_dev) != 0 &&
+                    root_st.st_dev == m->devnum) {
+                        n_failed ++;
+                        continue;
+                }
+
+                if ((r = delete_dm(m->devnum)) >= 0) {
+
+                        if (r > 0 && changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not delete dm %s: %m", m->path);
+                        n_failed++;
                 }
         }
 
-        return failed;
+        return n_failed;
 }
 
-int umount_all(void) {
+int umount_all(bool *changed) {
         int r;
         LIST_HEAD(MountPoint, mp_list_head);
 
@@ -360,11 +559,11 @@ int umount_all(void) {
         if (r < 0)
                 goto end;
 
-        r = mount_points_list_umount(&mp_list_head);
+        r = mount_points_list_umount(&mp_list_head, changed);
         if (r <= 0)
                 goto end;
 
-        r = mount_points_list_remount_read_only(&mp_list_head);
+        r = mount_points_list_remount_read_only(&mp_list_head, changed);
 
   end:
         mount_points_list_free(&mp_list_head);
@@ -372,7 +571,7 @@ int umount_all(void) {
         return r;
 }
 
-int swapoff_all(void) {
+int swapoff_all(bool *changed) {
         int r;
         LIST_HEAD(MountPoint, swap_list_head);
 
@@ -382,7 +581,7 @@ int swapoff_all(void) {
         if (r < 0)
                 goto end;
 
-        r = swap_points_list_off(&swap_list_head);
+        r = swap_points_list_off(&swap_list_head, changed);
 
   end:
         mount_points_list_free(&swap_list_head);
@@ -390,7 +589,7 @@ int swapoff_all(void) {
         return r;
 }
 
-int loopback_detach_all(void) {
+int loopback_detach_all(bool *changed) {
         int r;
         LIST_HEAD(MountPoint, loopback_list_head);
 
@@ -400,10 +599,28 @@ int loopback_detach_all(void) {
         if (r < 0)
                 goto end;
 
-        r = loopback_points_list_detach(&loopback_list_head);
+        r = loopback_points_list_detach(&loopback_list_head, changed);
 
   end:
         mount_points_list_free(&loopback_list_head);
 
         return r;
 }
+
+int dm_detach_all(bool *changed) {
+        int r;
+        LIST_HEAD(MountPoint, dm_list_head);
+
+        LIST_HEAD_INIT(MountPoint, dm_list_head);
+
+        r = dm_list_get(&dm_list_head);
+        if (r < 0)
+                goto end;
+
+        r = dm_points_list_detach(&dm_list_head, changed);
+
+  end:
+        mount_points_list_free(&dm_list_head);
+
+        return r;
+}