X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fumount.c;h=2d166c1c92c967a69f6d060b3b8c5c8bc15faf67;hp=83c9de3e8298635d8c2736a67cd71a932dbe9a2b;hb=a87f0f726ca6dc9fde11eea6591a244e77d2d182;hpb=024f268d634159849e642e7005871739c428524d diff --git a/src/core/umount.c b/src/core/umount.c index 83c9de3e8..2d166c1c9 100644 --- a/src/core/umount.c +++ b/src/core/umount.c @@ -27,7 +27,6 @@ #include #include #include -#include #include "list.h" #include "mount-setup.h" @@ -35,18 +34,20 @@ #include "path-util.h" #include "util.h" #include "virt.h" +#include "libudev.h" +#include "udev-util.h" typedef struct MountPoint { char *path; dev_t devnum; - LIST_FIELDS (struct MountPoint, mount_point); + LIST_FIELDS(struct MountPoint, mount_point); } MountPoint; static void mount_point_free(MountPoint **head, MountPoint *m) { assert(head); assert(m); - LIST_REMOVE(MountPoint, mount_point, *head, m); + LIST_REMOVE(mount_point, *head, m); free(m->path); free(m); @@ -124,7 +125,7 @@ static int mount_points_list_get(MountPoint **head) { } m->path = p; - LIST_PREPEND(MountPoint, mount_point, *head, m); + LIST_PREPEND(mount_point, *head, m); } r = 0; @@ -169,7 +170,7 @@ static int swap_list_get(MountPoint **head) { continue; } - if (endswith(dev, "(deleted)")) { + if (endswith(dev, " (deleted)")) { free(dev); continue; } @@ -189,7 +190,7 @@ static int swap_list_get(MountPoint **head) { } swap->path = d; - LIST_PREPEND(MountPoint, mount_point, *head, swap); + LIST_PREPEND(mount_point, *head, swap); } r = 0; @@ -201,161 +202,130 @@ finish: } static int loopback_list_get(MountPoint **head) { - int r; - struct udev *udev; - struct udev_enumerate *e = NULL; + _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL; struct udev_list_entry *item = NULL, *first = NULL; + _cleanup_udev_unref_ struct udev *udev = NULL; + int r; assert(head); - if (!(udev = udev_new())) { - r = -ENOMEM; - goto finish; - } + udev = udev_new(); + if (!udev) + return -ENOMEM; - if (!(e = udev_enumerate_new(udev))) { - r = -ENOMEM; - goto finish; - } + e = udev_enumerate_new(udev); + if (!e) + return -ENOMEM; - if (udev_enumerate_add_match_subsystem(e, "block") < 0 || - udev_enumerate_add_match_sysname(e, "loop*") < 0) { - r = -EIO; - goto finish; - } + r = udev_enumerate_add_match_subsystem(e, "block"); + if (r < 0) + return r; - if (udev_enumerate_scan_devices(e) < 0) { - r = -EIO; - goto finish; - } + r = udev_enumerate_add_match_sysname(e, "loop*"); + if (r < 0) + return r; + + r = udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL); + if (r < 0) + return r; + + r = udev_enumerate_scan_devices(e); + if (r < 0) + return r; first = udev_enumerate_get_list_entry(e); udev_list_entry_foreach(item, first) { MountPoint *lb; - struct udev_device *d; + _cleanup_udev_device_unref_ 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; - } + d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); + if (!d) + return -ENOMEM; - if (!(dn = udev_device_get_devnode(d))) { - udev_device_unref(d); + dn = udev_device_get_devnode(d); + if (!dn) continue; - } loop = strdup(dn); - udev_device_unref(d); + if (!loop) + return -ENOMEM; - if (!loop) { - r = -ENOMEM; - goto finish; - } - - if (!(lb = new0(MountPoint, 1))) { + lb = new0(MountPoint, 1); + if (!lb) { free(loop); - r = -ENOMEM; - goto finish; + return -ENOMEM; } lb->path = loop; - LIST_PREPEND(MountPoint, mount_point, *head, lb); + LIST_PREPEND(mount_point, *head, lb); } - r = 0; - -finish: - if (e) - udev_enumerate_unref(e); - - if (udev) - udev_unref(udev); - - return r; + return 0; } static int dm_list_get(MountPoint **head) { - int r; - struct udev *udev; - struct udev_enumerate *e = NULL; + _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL; struct udev_list_entry *item = NULL, *first = NULL; + _cleanup_udev_unref_ struct udev *udev = NULL; + int r; assert(head); - if (!(udev = udev_new())) { - r = -ENOMEM; - goto finish; - } + udev = udev_new(); + if (!udev) + return -ENOMEM; - if (!(e = udev_enumerate_new(udev))) { - r = -ENOMEM; - goto finish; - } + e = udev_enumerate_new(udev); + if (!e) + return -ENOMEM; - if (udev_enumerate_add_match_subsystem(e, "block") < 0 || - udev_enumerate_add_match_sysname(e, "dm-*") < 0) { - r = -EIO; - goto finish; - } + r = udev_enumerate_add_match_subsystem(e, "block"); + if (r < 0) + return r; - if (udev_enumerate_scan_devices(e) < 0) { - r = -EIO; - goto finish; - } + r = udev_enumerate_add_match_sysname(e, "dm-*"); + if (r < 0) + return r; - first = udev_enumerate_get_list_entry(e); + r = udev_enumerate_scan_devices(e); + if (r < 0) + return r; + first = udev_enumerate_get_list_entry(e); udev_list_entry_foreach(item, first) { MountPoint *m; - struct udev_device *d; + _cleanup_udev_device_unref_ struct udev_device *d; dev_t devnum; char *node; const char *dn; - if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) { - r = -ENOMEM; - goto finish; - } + d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); + if (!d) + return -ENOMEM; devnum = udev_device_get_devnum(d); dn = udev_device_get_devnode(d); - - if (major(devnum) == 0 || !dn) { - udev_device_unref(d); + if (major(devnum) == 0 || !dn) continue; - } node = strdup(dn); - udev_device_unref(d); - - if (!node) { - r = -ENOMEM; - goto finish; - } + if (!node) + return -ENOMEM; - if (!(m = new(MountPoint, 1))) { + m = new(MountPoint, 1); + if (!m) { free(node); - r = -ENOMEM; - goto finish; + return -ENOMEM; } m->path = node; m->devnum = devnum; - LIST_PREPEND(MountPoint, mount_point, *head, m); + LIST_PREPEND(mount_point, *head, m); } - r = 0; - -finish: - if (e) - udev_enumerate_unref(e); - - if (udev) - udev_unref(udev); - - return r; + return 0; } static int delete_loopback(const char *device) { @@ -378,25 +348,23 @@ static int delete_loopback(const char *device) { } static int delete_dm(dev_t devnum) { - int fd, r; - struct dm_ioctl dm; + _cleanup_close_ int fd = -1; + int r; + struct dm_ioctl dm = { + .version = {DM_VERSION_MAJOR, + DM_VERSION_MINOR, + DM_VERSION_PATCHLEVEL}, + .data_size = sizeof(dm), + .dev = devnum, + }; assert(major(devnum) != 0); - if ((fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC)) < 0) + fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC); + if (fd < 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; } @@ -407,18 +375,46 @@ static int mount_points_list_umount(MountPoint **head, bool *changed, bool log_e assert(head); LIST_FOREACH_SAFE(mount_point, m, n, *head) { + + /* If we are in a container, don't attempt to + read-only mount anything as that brings no real + benefits, but might confuse the host, as we remount + the superblock here, not the bind mound. */ + if (detect_container(NULL) <= 0) { + /* We always try to remount directories + * read-only first, before we go on and umount + * them. + * + * Mount points can be stacked. If a mount + * point is stacked below / or /usr, we + * cannot umount or remount it directly, + * since there is no way to refer to the + * underlying mount. There's nothing we can do + * about it for the general case, but we can + * do something about it if it is aliased + * somehwere else via a bind mount. If we + * explicitly remount the super block of that + * alias read-only we hence should be + * relatively safe regarding keeping the fs we + * can otherwise not see dirty. */ + mount(NULL, m->path, NULL, MS_REMOUNT|MS_RDONLY, NULL); + } + + /* Skip / and /usr since we cannot unmount that + * anyway, since we are running from it. They have + * already been remounted ro. */ if (path_equal(m->path, "/") #ifndef HAVE_SPLIT_USR || path_equal(m->path, "/usr") #endif - ) { - n_failed++; + ) continue; - } - /* Trying to umount. Forcing to umount if busy (only for NFS mounts) */ - if (umount2(m->path, MNT_FORCE) == 0) { - log_info("Unmounted %s.", m->path); + /* Trying to umount. We don't force here since we rely + * on busy NFS and FUSE file systems to return EBUSY + * until we closed everything on top of them. */ + log_info("Unmounting %s.", m->path); + if (umount2(m->path, 0) == 0) { if (changed) *changed = true; @@ -432,29 +428,6 @@ static int mount_points_list_umount(MountPoint **head, bool *changed, bool log_e return n_failed; } -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) { - - /* Trying to remount read-only */ - if (mount(NULL, m->path, NULL, 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; @@ -462,6 +435,7 @@ static int swap_points_list_off(MountPoint **head, bool *changed) { assert(head); LIST_FOREACH_SAFE(mount_point, m, n, *head) { + log_info("Deactivating swap %s.", m->path); if (swapoff(m->path) == 0) { if (changed) *changed = true; @@ -497,14 +471,15 @@ static int loopback_points_list_detach(MountPoint **head, bool *changed) { continue; } - if ((r = delete_loopback(m->path)) >= 0) { - + log_info("Detaching loopback %s.", m->path); + r = delete_loopback(m->path); + if (r >= 0) { if (r > 0 && changed) *changed = true; mount_point_free(head, m); } else { - log_warning("Could not delete loopback %s: %m", m->path); + log_warning("Could not detach loopback %s: %m", m->path); n_failed++; } } @@ -531,14 +506,15 @@ static int dm_points_list_detach(MountPoint **head, bool *changed) { continue; } - if ((r = delete_dm(m->devnum)) >= 0) { - - if (r > 0 && changed) + log_info("Detaching DM %u:%u.", major(m->devnum), minor(m->devnum)); + r = delete_dm(m->devnum); + if (r >= 0) { + if (changed) *changed = true; mount_point_free(head, m); } else { - log_warning("Could not delete dm %s: %m", m->path); + log_warning("Could not detach DM %s: %m", m->path); n_failed++; } } @@ -551,7 +527,7 @@ int umount_all(bool *changed) { bool umount_changed; LIST_HEAD(MountPoint, mp_list_head); - LIST_HEAD_INIT(MountPoint, mp_list_head); + LIST_HEAD_INIT(mp_list_head); r = mount_points_list_get(&mp_list_head); if (r < 0) goto end; @@ -571,13 +547,6 @@ int umount_all(bool *changed) { if (r <= 0) goto end; - /* If we are in a container, don't attempt to read-only mount - anything as that brings no real benefits, but might confuse - the host, as we remount the superblock here, not the bind - mound. */ - if (detect_container(NULL) <= 0) - r = mount_points_list_remount_read_only(&mp_list_head, changed); - end: mount_points_list_free(&mp_list_head); @@ -588,7 +557,7 @@ int swapoff_all(bool *changed) { int r; LIST_HEAD(MountPoint, swap_list_head); - LIST_HEAD_INIT(MountPoint, swap_list_head); + LIST_HEAD_INIT(swap_list_head); r = swap_list_get(&swap_list_head); if (r < 0) @@ -606,7 +575,7 @@ int loopback_detach_all(bool *changed) { int r; LIST_HEAD(MountPoint, loopback_list_head); - LIST_HEAD_INIT(MountPoint, loopback_list_head); + LIST_HEAD_INIT(loopback_list_head); r = loopback_list_get(&loopback_list_head); if (r < 0) @@ -624,7 +593,7 @@ int dm_detach_all(bool *changed) { int r; LIST_HEAD(MountPoint, dm_list_head); - LIST_HEAD_INIT(MountPoint, dm_list_head); + LIST_HEAD_INIT(dm_list_head); r = dm_list_get(&dm_list_head); if (r < 0)