X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fumount.c;h=95efa8204b2e9e9cb11e2cf07666d1556251354d;hp=44bed611ea7482e53ddeed993a5001c32853277e;hb=dee87d612d295d9c8642b76c716b8e357411e65a;hpb=7e23b34c7da85e24c92e984f1d99eead3e9817f5 diff --git a/src/umount.c b/src/umount.c index 44bed611e..95efa8204 100644 --- a/src/umount.c +++ b/src/umount.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include "list.h" @@ -35,44 +36,44 @@ 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; +}