stat-util: provide single fallback implementation of statx()
This simplifies things quite a bit, and is reusable wherever we want to
use statx() later on. Not sure why I didn't do it like this right from
the beginning...
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index 36e31d0..aec8ddc 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -517,7 +517,6 @@
int maxdepth,
bool keep_this_level) {
- static bool use_statx = true;
bool deleted = false;
struct dirent *dent;
int r = 0;
@@ -525,110 +524,73 @@
FOREACH_DIRENT_ALL(dent, d, break) {
_cleanup_free_ char *sub_path = NULL;
nsec_t atime_nsec, mtime_nsec, ctime_nsec, btime_nsec;
- mode_t mode;
- uid_t uid;
if (dot_or_dot_dot(dent->d_name))
continue;
- if (use_statx) {
- /* If statx() is supported, use it. It's preferable over fstatat() since it tells us
- * explicitly where we are looking at a mount point, for free as side
- * information. Determing the same information without statx() is hard, see the
- * complexity of path_is_mount_point(), and also much slower as it requires a numbre
- * of syscalls instead of just one. Hence, when we have modern statx() we use it
- * instead of fstat() and do proper mount point checks, while on older kernels's well
- * do traditional st_dev based detection of mount points.
- *
- * Using statx() for detecting mount points also has the benfit that we handle weird
- * file systems such as overlayfs better where each file is originating from a
- * different st_dev. */
+ /* If statx() is supported, use it. It's preferable over fstatat() since it tells us
+ * explicitly where we are looking at a mount point, for free as side information. Determing
+ * the same information without statx() is hard, see the complexity of path_is_mount_point(),
+ * and also much slower as it requires a number of syscalls instead of just one. Hence, when
+ * we have modern statx() we use it instead of fstat() and do proper mount point checks,
+ * while on older kernels's well do traditional st_dev based detection of mount points.
+ *
+ * Using statx() for detecting mount points also has the benfit that we handle weird file
+ * systems such as overlayfs better where each file is originating from a different
+ * st_dev. */
- STRUCT_STATX_DEFINE(sx);
+ STRUCT_STATX_DEFINE(sx);
- if (statx(dirfd(d), dent->d_name,
- AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT,
- STATX_TYPE|STATX_MODE|STATX_UID|STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_BTIME,
- &sx) < 0) {
-
- if (errno == ENOENT)
- continue;
- if (ERRNO_IS_NOT_SUPPORTED(errno) || errno == EPERM)
- use_statx = false; /* Not supported or blocked by seccomp or so */
- else {
- /* FUSE, NFS mounts, SELinux might return EACCES */
- r = log_full_errno(errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
- "statx(%s/%s) failed: %m", p, dent->d_name);
- continue;
- }
- } else {
- if (FLAGS_SET(sx.stx_attributes_mask, STATX_ATTR_MOUNT_ROOT)) {
- /* Yay, we have the mount point API, use it */
- if (FLAGS_SET(sx.stx_attributes, STATX_ATTR_MOUNT_ROOT)) {
- log_debug("Ignoring \"%s/%s\": different mount points.", p, dent->d_name);
- continue;
- }
- } else {
- /* So we have statx() but the STATX_ATTR_MOUNT_ROOT flag is not
- * supported, fall back to traditional stx_dev checking. */
- if (sx.stx_dev_major != rootdev_major ||
- sx.stx_dev_minor != rootdev_minor) {
- log_debug("Ignoring \"%s/%s\": different filesystem.", p, dent->d_name);
- continue;
- }
- }
-
- mode = sx.stx_mode;
- uid = sx.stx_uid;
- atime_nsec = FLAGS_SET(sx.stx_mask, STATX_ATIME) ? load_statx_timestamp_nsec(&sx.stx_atime) : 0;
- mtime_nsec = FLAGS_SET(sx.stx_mask, STATX_MTIME) ? load_statx_timestamp_nsec(&sx.stx_mtime) : 0;
- ctime_nsec = FLAGS_SET(sx.stx_mask, STATX_CTIME) ? load_statx_timestamp_nsec(&sx.stx_ctime) : 0;
- btime_nsec = FLAGS_SET(sx.stx_mask, STATX_BTIME) ? load_statx_timestamp_nsec(&sx.stx_btime) : 0;
- }
+ r = statx_fallback(
+ dirfd(d), dent->d_name,
+ AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT,
+ STATX_TYPE|STATX_MODE|STATX_UID|STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_BTIME,
+ &sx);
+ if (r == -ENOENT)
+ continue;
+ if (r < 0) {
+ /* FUSE, NFS mounts, SELinux might return EACCES */
+ r = log_full_errno(errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
+ "statx(%s/%s) failed: %m", p, dent->d_name);
+ continue;
}
- if (!use_statx) {
- struct stat s;
-
- if (fstatat(dirfd(d), dent->d_name, &s, AT_SYMLINK_NOFOLLOW) < 0) {
- if (errno == ENOENT)
- continue;
-
- /* FUSE, NFS mounts, SELinux might return EACCES */
- r = log_full_errno(errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
- "stat(%s/%s) failed: %m", p, dent->d_name);
+ if (FLAGS_SET(sx.stx_attributes_mask, STATX_ATTR_MOUNT_ROOT)) {
+ /* Yay, we have the mount point API, use it */
+ if (FLAGS_SET(sx.stx_attributes, STATX_ATTR_MOUNT_ROOT)) {
+ log_debug("Ignoring \"%s/%s\": different mount points.", p, dent->d_name);
continue;
}
-
- /* Stay on the same filesystem */
- if (major(s.st_dev) != rootdev_major || minor(s.st_dev) != rootdev_minor) {
+ } else {
+ /* So we might have statx() but the STATX_ATTR_MOUNT_ROOT flag is not supported, fall
+ * back to traditional stx_dev checking. */
+ if (sx.stx_dev_major != rootdev_major ||
+ sx.stx_dev_minor != rootdev_minor) {
log_debug("Ignoring \"%s/%s\": different filesystem.", p, dent->d_name);
continue;
}
- mode = s.st_mode;
- uid = s.st_uid;
- atime_nsec = timespec_load_nsec(&s.st_atim);
- mtime_nsec = timespec_load_nsec(&s.st_mtim);
- ctime_nsec = timespec_load_nsec(&s.st_ctim);
- btime_nsec = 0;
- }
+ /* Try to detect bind mounts of the same filesystem instance; they do not differ in device
+ * major/minors. This type of query is not supported on all kernels or filesystem types
+ * though. */
+ if (S_ISDIR(sx.stx_mode)) {
+ int q;
- /* Try to detect bind mounts of the same filesystem instance; they
- * do not differ in device major/minors. This type of query is not
- * supported on all kernels or filesystem types though. */
- if (S_ISDIR(mode)) {
- int q;
-
- q = fd_is_mount_point(dirfd(d), dent->d_name, 0);
- if (q < 0)
- log_debug_errno(q, "Failed to determine whether \"%s/%s\" is a mount point, ignoring: %m", p, dent->d_name);
- else if (q > 0) {
- log_debug("Ignoring \"%s/%s\": different mount of the same filesystem.", p, dent->d_name);
- continue;
+ q = fd_is_mount_point(dirfd(d), dent->d_name, 0);
+ if (q < 0)
+ log_debug_errno(q, "Failed to determine whether \"%s/%s\" is a mount point, ignoring: %m", p, dent->d_name);
+ else if (q > 0) {
+ log_debug("Ignoring \"%s/%s\": different mount of the same filesystem.", p, dent->d_name);
+ continue;
+ }
}
}
+ atime_nsec = FLAGS_SET(sx.stx_mask, STATX_ATIME) ? load_statx_timestamp_nsec(&sx.stx_atime) : 0;
+ mtime_nsec = FLAGS_SET(sx.stx_mask, STATX_MTIME) ? load_statx_timestamp_nsec(&sx.stx_mtime) : 0;
+ ctime_nsec = FLAGS_SET(sx.stx_mask, STATX_CTIME) ? load_statx_timestamp_nsec(&sx.stx_ctime) : 0;
+ btime_nsec = FLAGS_SET(sx.stx_mask, STATX_BTIME) ? load_statx_timestamp_nsec(&sx.stx_btime) : 0;
+
sub_path = path_join(p, dent->d_name);
if (!sub_path) {
r = log_oom();
@@ -646,12 +608,12 @@
continue;
}
- if (S_ISDIR(mode)) {
+ if (S_ISDIR(sx.stx_mode)) {
_cleanup_closedir_ DIR *sub_dir = NULL;
if (mountpoint &&
streq(dent->d_name, "lost+found") &&
- uid == 0) {
+ sx.stx_uid == 0) {
log_debug("Ignoring directory \"%s\".", sub_path);
continue;
}
@@ -727,14 +689,14 @@
} else {
/* Skip files for which the sticky bit is set. These are semantics we define, and are
* unknown elsewhere. See XDG_RUNTIME_DIR specification for details. */
- if (mode & S_ISVTX) {
+ if (sx.stx_mode & S_ISVTX) {
log_debug("Skipping \"%s\": sticky bit set.", sub_path);
continue;
}
if (mountpoint &&
- S_ISREG(mode) &&
- uid == 0 &&
+ S_ISREG(sx.stx_mode) &&
+ sx.stx_uid == 0 &&
STR_IN_SET(dent->d_name,
".journal",
"aquota.user",
@@ -744,13 +706,13 @@
}
/* Ignore sockets that are listed in /proc/net/unix */
- if (S_ISSOCK(mode) && unix_socket_alive(sub_path)) {
+ if (S_ISSOCK(sx.stx_mode) && unix_socket_alive(sub_path)) {
log_debug("Skipping \"%s\": live socket.", sub_path);
continue;
}
/* Ignore device nodes */
- if (S_ISCHR(mode) || S_ISBLK(mode)) {
+ if (S_ISCHR(sx.stx_mode) || S_ISBLK(sx.stx_mode)) {
log_debug("Skipping \"%s\": a device.", sub_path);
continue;
}
@@ -2286,12 +2248,9 @@
static int clean_item_instance(Item *i, const char* instance) {
char timestamp[FORMAT_TIMESTAMP_MAX];
_cleanup_closedir_ DIR *d = NULL;
- uint32_t dev_major, dev_minor;
- nsec_t atime_nsec, mtime_nsec;
STRUCT_STATX_DEFINE(sx);
- int mountpoint = -1;
+ int mountpoint, r;
usec_t cutoff, n;
- uint64_t ino;
assert(i);
@@ -2314,53 +2273,34 @@
return log_error_errno(errno, "Failed to open directory %s: %m", instance);
}
- if (statx(dirfd(d), "", AT_EMPTY_PATH, STATX_MODE|STATX_INO|STATX_ATIME|STATX_MTIME, &sx) < 0) {
- struct stat s;
+ r = statx_fallback(dirfd(d), "", AT_EMPTY_PATH, STATX_MODE|STATX_INO|STATX_ATIME|STATX_MTIME, &sx);
+ if (r < 0)
+ return log_error_errno(r, "statx(%s) failed: %m", instance);
- if (!ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
- return log_error_errno(errno, "statx(%s) failed: %m", i->path);
-
- if (fstat(dirfd(d), &s) < 0)
- return log_error_errno(errno, "stat(%s) failed: %m", i->path);
-
- dev_major = major(s.st_dev);
- dev_minor = minor(s.st_dev);
- ino = s.st_ino;
- atime_nsec = timespec_load_nsec(&s.st_atim);
- mtime_nsec = timespec_load_nsec(&s.st_mtim);
- } else {
-
- if (FLAGS_SET(sx.stx_attributes_mask, STATX_ATTR_MOUNT_ROOT))
- mountpoint = FLAGS_SET(sx.stx_attributes, STATX_ATTR_MOUNT_ROOT);
-
- dev_major = sx.stx_dev_major;
- dev_minor = sx.stx_dev_minor;
- ino = sx.stx_ino;
- atime_nsec = load_statx_timestamp_nsec(&sx.stx_atime);
- mtime_nsec = load_statx_timestamp_nsec(&sx.stx_mtime);
- }
-
- if (mountpoint < 0) {
+ if (FLAGS_SET(sx.stx_attributes_mask, STATX_ATTR_MOUNT_ROOT))
+ mountpoint = FLAGS_SET(sx.stx_attributes, STATX_ATTR_MOUNT_ROOT);
+ else {
struct stat ps;
if (fstatat(dirfd(d), "..", &ps, AT_SYMLINK_NOFOLLOW) != 0)
return log_error_errno(errno, "stat(%s/..) failed: %m", i->path);
mountpoint =
- dev_major != major(ps.st_dev) ||
- dev_minor != minor(ps.st_dev) ||
- ino != ps.st_ino;
+ sx.stx_dev_major != major(ps.st_dev) ||
+ sx.stx_dev_minor != minor(ps.st_dev) ||
+ sx.stx_ino != ps.st_ino;
}
-
log_debug("Cleanup threshold for %s \"%s\" is %s",
mountpoint ? "mount point" : "directory",
instance,
format_timestamp_style(timestamp, sizeof(timestamp), cutoff, TIMESTAMP_US));
return dir_cleanup(i, instance, d,
- atime_nsec, mtime_nsec, cutoff * NSEC_PER_USEC,
- dev_major, dev_minor, mountpoint,
+ load_statx_timestamp_nsec(&sx.stx_atime),
+ load_statx_timestamp_nsec(&sx.stx_mtime),
+ cutoff * NSEC_PER_USEC,
+ sx.stx_dev_major, sx.stx_dev_minor, mountpoint,
MAX_DEPTH, i->keep_first_level);
}