diff options
| -rw-r--r-- | src/shared/libmount-util.c | 19 | ||||
| -rw-r--r-- | src/shared/libmount-util.h | 4 | ||||
| -rw-r--r-- | src/shutdown/umount.c | 68 | ||||
| -rw-r--r-- | src/shutdown/umount.h | 1 |
4 files changed, 90 insertions, 2 deletions
diff --git a/src/shared/libmount-util.c b/src/shared/libmount-util.c index bcb21b5aba..3818904733 100644 --- a/src/shared/libmount-util.c +++ b/src/shared/libmount-util.c @@ -38,3 +38,22 @@ int libmount_parse( *ret_iter = TAKE_PTR(iter); return 0; } + +int libmount_is_leaf( + struct libmnt_table *table, + struct libmnt_fs *fs) { + int r; + + _cleanup_(mnt_free_iterp) struct libmnt_iter *iter_children = NULL; + iter_children = mnt_new_iter(MNT_ITER_FORWARD); + if (!iter_children) + return log_oom(); + + /* We care only whether it exists, it is unused */ + _unused_ struct libmnt_fs *child; + r = mnt_table_next_child_fs(table, iter_children, fs, &child); + if (r < 0) + return r; + + return r == 1; +} diff --git a/src/shared/libmount-util.h b/src/shared/libmount-util.h index 6f6f36ad52..2f789e7426 100644 --- a/src/shared/libmount-util.h +++ b/src/shared/libmount-util.h @@ -14,3 +14,7 @@ int libmount_parse( FILE *source, struct libmnt_table **ret_table, struct libmnt_iter **ret_iter); + +int libmount_is_leaf( + struct libmnt_table *table, + struct libmnt_fs *fs); diff --git a/src/shutdown/umount.c b/src/shutdown/umount.c index 1326b32f6a..61bd9d2601 100644 --- a/src/shutdown/umount.c +++ b/src/shutdown/umount.c @@ -23,6 +23,7 @@ #include "alloc-util.h" #include "blockdev-util.h" +#include "chase-symlinks.h" #include "constants.h" #include "device-util.h" #include "dirent-util.h" @@ -32,13 +33,16 @@ #include "fs-util.h" #include "fstab-util.h" #include "libmount-util.h" +#include "mkdir.h" #include "mount-setup.h" #include "mount-util.h" #include "mountpoint-util.h" #include "parse-util.h" #include "path-util.h" #include "process-util.h" +#include "random-util.h" #include "signal-util.h" +#include "stat-util.h" #include "string-util.h" #include "strv.h" #include "sync-util.h" @@ -155,6 +159,11 @@ int mount_points_list_get(const char *mountinfo, MountPoint **head) { if (!m) return log_oom(); + r = libmount_is_leaf(table, fs); + if (r < 0) + return log_error_errno(r, "Failed to get children mounts for %s from %s: %m", path, mountinfo ?: "/proc/self/mountinfo"); + bool leaf = r; + *m = (MountPoint) { .remount_options = remount_options, .remount_flags = remount_flags, @@ -163,6 +172,7 @@ int mount_points_list_get(const char *mountinfo, MountPoint **head) { /* Unmount sysfs/procfs/… lazily, since syncing doesn't matter there, and it's OK if * something keeps an fd open to it. */ .umount_lazily = is_api_vfs, + .leaf = leaf, }; m->path = strdup(path); @@ -709,7 +719,8 @@ static int umount_with_timeout(MountPoint *m, bool last_try) { /* This includes remounting readonly, which changes the kernel mount options. Therefore the list passed to * this function is invalidated, and should not be reused. */ static int mount_points_list_umount(MountPoint **head, bool *changed, bool last_try) { - int n_failed = 0; + int n_failed = 0, r; + _cleanup_free_ char *resolved_mounts_path = NULL; assert(head); assert(changed); @@ -744,10 +755,63 @@ static int mount_points_list_umount(MountPoint **head, bool *changed, bool last_ continue; /* Trying to umount */ - if (umount_with_timeout(m, last_try) < 0) + r = umount_with_timeout(m, last_try); + if (r < 0) n_failed++; else *changed = true; + + /* If a mount is busy, we move it to not keep parent mount points busy. + * If a mount point is not a leaf, moving it would invalidate our mount table. + * More moving will occur in next iteration with a fresh mount table. + */ + if (r != -EBUSY || !m->leaf) + continue; + + _cleanup_free_ char *dirname = NULL; + + r = path_extract_directory(m->path, &dirname); + if (r < 0) { + n_failed++; + log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Cannot find directory for %s: %m", m->path); + continue; + } + + /* We need to canonicalize /run/shutdown/mounts. We cannot compare inodes, since /run + * might be bind mounted somewhere we want to unmount. And we need to move all mounts in + * /run/shutdown/mounts from there. + */ + if (!resolved_mounts_path) + (void) chase_symlinks("/run/shutdown/mounts", NULL, 0, &resolved_mounts_path, NULL); + if (!path_equal(dirname, resolved_mounts_path)) { + char newpath[STRLEN("/run/shutdown/mounts/") + 16 + 1]; + + xsprintf(newpath, "/run/shutdown/mounts/%016" PRIx64, random_u64()); + + /* on error of is_dir, assume directory */ + if (is_dir(m->path, true) != 0) { + r = mkdir_p(newpath, 0000); + if (r < 0) { + log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not create directory %s: %m", newpath); + continue; + } + } else { + r = touch_file(newpath, /* parents= */ true, USEC_INFINITY, UID_INVALID, GID_INVALID, 0700); + if (r < 0) { + log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not create file %s: %m", newpath); + continue; + } + } + + log_info("Moving mount %s to %s.", m->path, newpath); + + r = RET_NERRNO(mount(m->path, newpath, NULL, MS_MOVE, NULL)); + if (r < 0) { + n_failed++; + log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not move %s to %s: %m", m->path, newpath); + } else + *changed = true; + } } return n_failed; diff --git a/src/shutdown/umount.h b/src/shutdown/umount.h index 6261e719b0..a742ac0af5 100644 --- a/src/shutdown/umount.h +++ b/src/shutdown/umount.h @@ -20,6 +20,7 @@ typedef struct MountPoint { unsigned long remount_flags; bool try_remount_ro; bool umount_lazily; + bool leaf; dev_t devnum; LIST_FIELDS(struct MountPoint, mount_point); } MountPoint; |