X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fumount.c;h=1e95ad70dd0beb85394c23fab0b6e25f9075ee7e;hp=488e1e4a4d84941c2887ed64f1cb5922b5334705;hb=a57f7e2c828b852eb32fd810dcea041bb2975501;hpb=146de8175e11c877908f20f8ed1b5a3805455c0a diff --git a/src/core/umount.c b/src/core/umount.c index 488e1e4a4..1e95ad70d 100644 --- a/src/core/umount.c +++ b/src/core/umount.c @@ -32,12 +32,13 @@ #include "list.h" #include "mount-setup.h" #include "umount.h" +#include "path-util.h" #include "util.h" +#include "virt.h" typedef struct MountPoint { char *path; dev_t devnum; - bool skip_ro; LIST_FIELDS (struct MountPoint, mount_point); } MountPoint; @@ -72,8 +73,6 @@ static int mount_points_list_get(MountPoint **head) { for (i = 1;; i++) { int k; MountPoint *m; - char *root; - bool skip_ro; path = p = NULL; @@ -81,7 +80,7 @@ static int mount_points_list_get(MountPoint **head) { "%*s " /* (1) mount id */ "%*s " /* (2) parent id */ "%*s " /* (3) major:minor */ - "%ms " /* (4) root */ + "%*s " /* (4) root */ "%ms " /* (5) mount point */ "%*s" /* (6) mount options */ "%*[^-]" /* (7) optional fields */ @@ -90,8 +89,7 @@ static int mount_points_list_get(MountPoint **head) { "%*s" /* (10) mount source */ "%*s" /* (11) mount options 2 */ "%*[^\n]", /* some rubbish at the end */ - &root, - &path)) != 2) { + &path)) != 1) { if (k == EOF) break; @@ -101,11 +99,6 @@ static int mount_points_list_get(MountPoint **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); @@ -131,7 +124,6 @@ static int mount_points_list_get(MountPoint **head) { } m->path = p; - m->skip_ro = skip_ro; LIST_PREPEND(MountPoint, mount_point, *head, m); } @@ -227,7 +219,8 @@ static int loopback_list_get(MountPoint **head) { } if (udev_enumerate_add_match_subsystem(e, "block") < 0 || - udev_enumerate_add_match_sysname(e, "loop*") < 0) { + udev_enumerate_add_match_sysname(e, "loop*") < 0 || + udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL) < 0) { r = -EIO; goto finish; } @@ -386,25 +379,23 @@ 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; } @@ -415,18 +406,46 @@ 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; @@ -440,34 +459,6 @@ 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) { - - if (m->skip_ro) { - n_failed++; - continue; - } - - /* Trying to remount read-only */ - 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; @@ -475,6 +466,7 @@ 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; @@ -510,14 +502,15 @@ 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++; } } @@ -544,14 +537,15 @@ 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++; } } @@ -562,11 +556,9 @@ static int dm_points_list_detach(MountPoint **head, bool *changed) { int umount_all(bool *changed) { int r; bool umount_changed; - LIST_HEAD(MountPoint, mp_list_head); LIST_HEAD_INIT(MountPoint, mp_list_head); - r = mount_points_list_get(&mp_list_head); if (r < 0) goto end; @@ -586,8 +578,6 @@ int umount_all(bool *changed) { if (r <= 0) goto end; - r = mount_points_list_remount_read_only(&mp_list_head, changed); - end: mount_points_list_free(&mp_list_head);