diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/shared/condition.c | 42 | ||||
| -rw-r--r-- | src/update-done/update-done.c | 76 |
2 files changed, 73 insertions, 45 deletions
diff --git a/src/shared/condition.c b/src/shared/condition.c index 6bb42c0692..f13fa6a9fd 100644 --- a/src/shared/condition.c +++ b/src/shared/condition.c @@ -37,6 +37,7 @@ #include "condition.h" #include "extract-word.h" #include "fd-util.h" +#include "fileio.h" #include "glob-util.h" #include "hostname-util.h" #include "ima-util.h" @@ -309,8 +310,45 @@ static int condition_test_needs_update(Condition *c) { if (lstat("/usr/", &usr) < 0) return true; - return usr.st_mtim.tv_sec > other.st_mtim.tv_sec || - (usr.st_mtim.tv_sec == other.st_mtim.tv_sec && usr.st_mtim.tv_nsec > other.st_mtim.tv_nsec); + /* + * First, compare seconds as they are always accurate... + */ + if (usr.st_mtim.tv_sec != other.st_mtim.tv_sec) + return usr.st_mtim.tv_sec > other.st_mtim.tv_sec; + + /* + * ...then compare nanoseconds. + * + * A false positive is only possible when /usr's nanoseconds > 0 + * (otherwise /usr cannot be strictly newer than the target file) + * AND the target file's nanoseconds == 0 + * (otherwise the filesystem supports nsec timestamps, see stat(2)). + */ + if (usr.st_mtim.tv_nsec > 0 && other.st_mtim.tv_nsec == 0) { + _cleanup_free_ char *timestamp_str = NULL; + uint64_t timestamp; + int r; + + r = parse_env_file(p, NULL, "TimestampNSec", ×tamp_str, NULL); + if (r < 0) { + log_error_errno(-r, "Failed to parse timestamp file '%s', using mtime: %m", p); + return true; + } else if (r == 0) { + log_debug("No data in timestamp file '%s', using mtime", p); + return true; + } + + r = safe_atou64(timestamp_str, ×tamp); + if (r < 0) { + log_error_errno(-r, "Failed to parse timestamp value '%s' in file '%s', using mtime: %m", + timestamp_str, p); + return true; + } + + other.st_mtim.tv_nsec = timestamp % NSEC_PER_SEC; + } + + return usr.st_mtim.tv_nsec > other.st_mtim.tv_nsec; } static int condition_test_first_boot(Condition *c) { diff --git a/src/update-done/update-done.c b/src/update-done/update-done.c index da306a4444..5cc5abfddf 100644 --- a/src/update-done/update-done.c +++ b/src/update-done/update-done.c @@ -23,67 +23,57 @@ #include "util.h" #define MESSAGE \ - "This file was created by systemd-update-done. Its only \n" \ - "purpose is to hold a timestamp of the time this directory\n" \ - "was updated. See systemd-update-done.service(8).\n" + "# This file was created by systemd-update-done. Its only \n" \ + "# purpose is to hold a timestamp of the time this directory\n" \ + "# was updated. See systemd-update-done.service(8).\n" static int apply_timestamp(const char *path, struct timespec *ts) { struct timespec twice[2] = { *ts, *ts }; - struct stat st; + int fd = -1; + _cleanup_fclose_ FILE *f = NULL; + int r; assert(path); assert(ts); - if (stat(path, &st) >= 0) { - /* Is the timestamp file already newer than the OS? If - * so, there's nothing to do. We ignore the nanosecond - * component of the timestamp, since some file systems - * do not support any better accuracy than 1s and we - * have no way to identify the accuracy - * available. Most notably ext4 on small disks (where - * 128 byte inodes are used) does not support better - * accuracy than 1s. */ - if (st.st_mtim.tv_sec > ts->tv_sec) - return 0; - - /* It is older? Then let's update it */ - if (utimensat(AT_FDCWD, path, twice, AT_SYMLINK_NOFOLLOW) < 0) { - - if (errno == EROFS) - return log_debug("Can't update timestamp file %s, file system is read-only.", path); + /* + * We store the timestamp both as mtime of the file and in the file itself, + * to support filesystems which cannot store nanosecond-precision timestamps. + * Hence, don't bother updating the file, let's just rewrite it. + */ - return log_error_errno(errno, "Failed to update timestamp on %s: %m", path); - } + r = mac_selinux_create_file_prepare(path, S_IFREG); + if (r < 0) + return log_error_errno(r, "Failed to set SELinux context for %s: %m", path); - } else if (errno == ENOENT) { - _cleanup_close_ int fd = -1; - int r; + fd = open(path, O_CREAT|O_WRONLY|O_TRUNC|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644); + mac_selinux_create_file_clear(); - /* The timestamp file doesn't exist yet? Then let's create it. */ + if (fd < 0) { + if (errno == EROFS) + return log_debug("Can't create timestamp file %s, file system is read-only.", path); - r = mac_selinux_create_file_prepare(path, S_IFREG); - if (r < 0) - return log_error_errno(r, "Failed to set SELinux context for %s: %m", path); - - fd = open(path, O_CREAT|O_EXCL|O_WRONLY|O_TRUNC|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644); - mac_selinux_create_file_clear(); + return log_error_errno(errno, "Failed to create/open timestamp file %s: %m", path); + } - if (fd < 0) { - if (errno == EROFS) - return log_debug("Can't create timestamp file %s, file system is read-only.", path); + f = fdopen(fd, "w"); + if (!f) { + safe_close(fd); + return log_error_errno(errno, "Failed to fdopen() timestamp file %s: %m", path); + } - return log_error_errno(errno, "Failed to create timestamp file %s: %m", path); - } + (void) fprintf(f, + "%s" + "TimestampNSec=" NSEC_FMT "\n", + MESSAGE, timespec_load_nsec(ts)); - (void) loop_write(fd, MESSAGE, strlen(MESSAGE), false); + fflush(f); - if (futimens(fd, twice) < 0) - return log_error_errno(errno, "Failed to update timestamp on %s: %m", path); - } else - log_error_errno(errno, "Failed to stat() timestamp file %s: %m", path); + if (futimens(fd, twice) < 0) + return log_error_errno(errno, "Failed to update timestamp on %s: %m", path); return 0; } |