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Diffstat (limited to 'src/core/umount.c')
-rw-r--r--src/core/umount.c198
1 files changed, 110 insertions, 88 deletions
diff --git a/src/core/umount.c b/src/core/umount.c
index de826edd4d..ab2d4ffa62 100644
--- a/src/core/umount.c
+++ b/src/core/umount.c
@@ -48,8 +48,9 @@
typedef struct MountPoint {
char *path;
- char *options;
- char *type;
+ char *remount_options;
+ unsigned long remount_flags;
+ bool try_remount_ro;
dev_t devnum;
LIST_FIELDS(struct MountPoint, mount_point);
} MountPoint;
@@ -61,8 +62,7 @@ static void mount_point_free(MountPoint **head, MountPoint *m) {
LIST_REMOVE(mount_point, *head, m);
free(m->path);
- free(m->options);
- free(m->type);
+ free(m->remount_options);
free(m);
}
@@ -85,8 +85,7 @@ static int mount_points_list_get(MountPoint **head) {
return -errno;
for (i = 1;; i++) {
- _cleanup_free_ char *path = NULL, *options = NULL, *type = NULL;
- char *p = NULL;
+ _cleanup_free_ char *path = NULL, *options = NULL, *flags = NULL, *type = NULL, *p = NULL;
MountPoint *m;
int k;
@@ -96,15 +95,15 @@ static int mount_points_list_get(MountPoint **head) {
"%*s " /* (3) major:minor */
"%*s " /* (4) root */
"%ms " /* (5) mount point */
- "%*s" /* (6) mount flags */
+ "%ms" /* (6) mount flags */
"%*[^-]" /* (7) optional fields */
"- " /* (8) separator */
"%ms " /* (9) file system type */
"%*s" /* (10) mount source */
"%ms" /* (11) mount options */
"%*[^\n]", /* some rubbish at the end */
- &path, &type, &options);
- if (k != 3) {
+ &path, &flags, &type, &options);
+ if (k != 4) {
if (k == EOF)
break;
@@ -127,22 +126,53 @@ static int mount_points_list_get(MountPoint **head) {
mount_point_ignore(p) ||
path_startswith(p, "/dev") ||
path_startswith(p, "/sys") ||
- path_startswith(p, "/proc")) {
- free(p);
+ path_startswith(p, "/proc"))
continue;
- }
m = new0(MountPoint, 1);
- if (!m) {
- free(p);
+ if (!m)
return -ENOMEM;
- }
- m->path = p;
- m->options = options;
- options = NULL;
- m->type = type;
- type = NULL;
+ free_and_replace(m->path, p);
+
+ /* 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 mount.
+ *
+ * If the filesystem is a network fs, also skip the
+ * remount. It brings no value (we cannot leave
+ * a "dirty fs") and could hang if the network is down.
+ * Note that umount2() is more careful and will not
+ * hang because of the network being down. */
+ m->try_remount_ro = detect_container() <= 0 &&
+ !fstype_is_network(type) &&
+ !fstype_is_api_vfs(type) &&
+ !fstype_is_ro(type) &&
+ !fstab_test_yes_no_option(options, "ro\0rw\0");
+
+ if (m->try_remount_ro) {
+ _cleanup_free_ char *unknown_flags = NULL;
+
+ /* mount(2) states that mount flags and options need to be exactly the same
+ * as they were when the filesystem was mounted, except for the desired
+ * changes. So we reconstruct both here and adjust them for the later
+ * remount call too. */
+
+ r = mount_option_mangle(flags, 0, &m->remount_flags, &unknown_flags);
+ if (r < 0)
+ return r;
+ if (!isempty(unknown_flags))
+ log_warning("Ignoring unknown mount flags '%s'.", unknown_flags);
+
+ r = mount_option_mangle(options, m->remount_flags, &m->remount_flags, &m->remount_options);
+ if (r < 0)
+ return r;
+
+ /* MS_BIND is special. If it is provided it will only make the mount-point
+ * read-only. If left out, the super block itself is remounted, which we want. */
+ m->remount_flags = (m->remount_flags|MS_REMOUNT|MS_RDONLY) & ~MS_BIND;
+ }
LIST_PREPEND(mount_point, *head, m);
}
@@ -333,6 +363,8 @@ static int delete_loopback(const char *device) {
_cleanup_close_ int fd = -1;
int r;
+ assert(device);
+
fd = open(device, O_RDONLY|O_CLOEXEC);
if (fd < 0)
return errno == ENOENT ? 0 : -errno;
@@ -382,12 +414,14 @@ static bool nonunmountable_path(const char *path) {
|| path_startswith(path, "/run/initramfs");
}
-static int remount_with_timeout(MountPoint *m, char *options, int *n_failed) {
+static int remount_with_timeout(MountPoint *m, int umount_log_level) {
pid_t pid;
int r;
BLOCK_SIGNALS(SIGCHLD);
+ assert(m);
+
/* Due to the possiblity of a remount operation hanging, we
* fork a child process and set a timeout. If the timeout
* lapses, the assumption is that that particular remount
@@ -396,12 +430,12 @@ static int remount_with_timeout(MountPoint *m, char *options, int *n_failed) {
if (r < 0)
return r;
if (r == 0) {
- log_info("Remounting '%s' read-only in with options '%s'.", m->path, options);
+ log_info("Remounting '%s' read-only in with options '%s'.", m->path, m->remount_options);
/* Start the mount operation here in the child */
- r = mount(NULL, m->path, NULL, MS_REMOUNT|MS_RDONLY, options);
+ r = mount(NULL, m->path, NULL, m->remount_flags, m->remount_options);
if (r < 0)
- log_error_errno(errno, "Failed to remount '%s' read-only: %m", m->path);
+ log_full_errno(umount_log_level, errno, "Failed to remount '%s' read-only: %m", m->path);
_exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
}
@@ -411,19 +445,21 @@ static int remount_with_timeout(MountPoint *m, char *options, int *n_failed) {
log_error_errno(r, "Remounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid);
(void) kill(pid, SIGKILL);
} else if (r == -EPROTO)
- log_error_errno(r, "Remounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
+ log_debug_errno(r, "Remounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
else if (r < 0)
log_error_errno(r, "Remounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid);
return r;
}
-static int umount_with_timeout(MountPoint *m, bool *changed) {
+static int umount_with_timeout(MountPoint *m, int umount_log_level) {
pid_t pid;
int r;
BLOCK_SIGNALS(SIGCHLD);
+ assert(m);
+
/* Due to the possiblity of a umount operation hanging, we
* fork a child process and set a timeout. If the timeout
* lapses, the assumption is that that particular umount
@@ -443,7 +479,7 @@ static int umount_with_timeout(MountPoint *m, bool *changed) {
* then return EBUSY).*/
r = umount2(m->path, MNT_FORCE);
if (r < 0)
- log_error_errno(errno, "Failed to unmount %s: %m", m->path);
+ log_full_errno(umount_log_level, errno, "Failed to unmount %s: %m", m->path);
_exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
}
@@ -453,7 +489,7 @@ static int umount_with_timeout(MountPoint *m, bool *changed) {
log_error_errno(r, "Unmounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid);
(void) kill(pid, SIGKILL);
} else if (r == -EPROTO)
- log_error_errno(r, "Unmounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
+ log_debug_errno(r, "Unmounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
else if (r < 0)
log_error_errno(r, "Unmounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid);
@@ -462,38 +498,15 @@ static int umount_with_timeout(MountPoint *m, bool *changed) {
/* 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) {
+static int mount_points_list_umount(MountPoint **head, bool *changed, int umount_log_level) {
MountPoint *m;
int n_failed = 0;
assert(head);
+ assert(changed);
LIST_FOREACH(mount_point, m, *head) {
- bool mount_is_readonly;
-
- mount_is_readonly = fstab_test_yes_no_option(m->options, "ro\0rw\0");
-
- /* 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 mount.
- If the filesystem is a network fs, also skip the
- remount. It brings no value (we cannot leave
- a "dirty fs") and could hang if the network is down.
- Note that umount2() is more careful and will not
- hang because of the network being down. */
- if (detect_container() <= 0 &&
- !fstype_is_network(m->type) &&
- !mount_is_readonly) {
- _cleanup_free_ char *options = NULL;
- /* MS_REMOUNT requires that the data parameter
- * should be the same from the original mount
- * except for the desired changes. Since we want
- * to remount read-only, we should filter out
- * rw (and ro too, because it confuses the kernel) */
- (void) fstab_filter_options(m->options, "rw\0ro\0", NULL, NULL, &options);
-
+ if (m->try_remount_ro) {
/* We always try to remount directories
* read-only first, before we go on and umount
* them.
@@ -508,16 +521,19 @@ static int mount_points_list_umount(MountPoint **head, bool *changed) {
* 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 dirty an fs
+ * relatively safe regarding keeping a dirty fs
* we cannot otherwise see.
*
* Since the remount can hang in the instance of
* remote filesystems, we remount asynchronously
- * and skip the subsequent umount if it fails */
- if (remount_with_timeout(m, options, &n_failed) < 0) {
- if (nonunmountable_path(m->path))
+ * and skip the subsequent umount if it fails. */
+ if (remount_with_timeout(m, umount_log_level) < 0) {
+ /* Remount failed, but try unmounting anyway,
+ * unless this is a mount point we want to skip. */
+ if (nonunmountable_path(m->path)) {
n_failed++;
- continue;
+ continue;
+ }
}
}
@@ -528,12 +544,10 @@ static int mount_points_list_umount(MountPoint **head, bool *changed) {
continue;
/* Trying to umount */
- if (umount_with_timeout(m, changed) < 0)
+ if (umount_with_timeout(m, umount_log_level) < 0)
n_failed++;
- else {
- if (changed)
- *changed = true;
- }
+ else
+ *changed = true;
}
return n_failed;
@@ -544,13 +558,12 @@ static int swap_points_list_off(MountPoint **head, bool *changed) {
int n_failed = 0;
assert(head);
+ assert(changed);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
log_info("Deactivating swap %s.", m->path);
if (swapoff(m->path) == 0) {
- if (changed)
- *changed = true;
-
+ *changed = true;
mount_point_free(head, m);
} else {
log_warning_errno(errno, "Could not deactivate swap %s: %m", m->path);
@@ -561,12 +574,13 @@ static int swap_points_list_off(MountPoint **head, bool *changed) {
return n_failed;
}
-static int loopback_points_list_detach(MountPoint **head, bool *changed) {
+static int loopback_points_list_detach(MountPoint **head, bool *changed, int umount_log_level) {
MountPoint *m, *n;
int n_failed = 0, k;
struct stat root_st;
assert(head);
+ assert(changed);
k = lstat("/", &root_st);
@@ -585,12 +599,12 @@ static int loopback_points_list_detach(MountPoint **head, bool *changed) {
log_info("Detaching loopback %s.", m->path);
r = delete_loopback(m->path);
if (r >= 0) {
- if (r > 0 && changed)
+ if (r > 0)
*changed = true;
mount_point_free(head, m);
} else {
- log_warning_errno(errno, "Could not detach loopback %s: %m", m->path);
+ log_full_errno(umount_log_level, errno, "Could not detach loopback %s: %m", m->path);
n_failed++;
}
}
@@ -598,12 +612,13 @@ static int loopback_points_list_detach(MountPoint **head, bool *changed) {
return n_failed;
}
-static int dm_points_list_detach(MountPoint **head, bool *changed) {
+static int dm_points_list_detach(MountPoint **head, bool *changed, int umount_log_level) {
MountPoint *m, *n;
int n_failed = 0, r;
dev_t rootdev;
assert(head);
+ assert(changed);
r = get_block_device("/", &rootdev);
if (r <= 0)
@@ -611,21 +626,18 @@ static int dm_points_list_detach(MountPoint **head, bool *changed) {
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
- if (major(rootdev) != 0)
- if (rootdev == m->devnum) {
- n_failed ++;
- continue;
- }
+ if (major(rootdev) != 0 && rootdev == m->devnum) {
+ n_failed ++;
+ continue;
+ }
log_info("Detaching DM %u:%u.", major(m->devnum), minor(m->devnum));
r = delete_dm(m->devnum);
if (r >= 0) {
- if (changed)
- *changed = true;
-
+ *changed = true;
mount_point_free(head, m);
} else {
- log_warning_errno(errno, "Could not detach DM %s: %m", m->path);
+ log_full_errno(umount_log_level, errno, "Could not detach DM %s: %m", m->path);
n_failed++;
}
}
@@ -633,16 +645,18 @@ static int dm_points_list_detach(MountPoint **head, bool *changed) {
return n_failed;
}
-static int umount_all_once(bool *changed) {
+static int umount_all_once(bool *changed, int umount_log_level) {
int r;
LIST_HEAD(MountPoint, mp_list_head);
+ assert(changed);
+
LIST_HEAD_INIT(mp_list_head);
r = mount_points_list_get(&mp_list_head);
if (r < 0)
goto end;
- r = mount_points_list_umount(&mp_list_head, changed);
+ r = mount_points_list_umount(&mp_list_head, changed, umount_log_level);
end:
mount_points_list_free(&mp_list_head);
@@ -650,17 +664,19 @@ static int umount_all_once(bool *changed) {
return r;
}
-int umount_all(bool *changed) {
+int umount_all(bool *changed, int umount_log_level) {
bool umount_changed;
int r;
+ assert(changed);
+
/* Retry umount, until nothing can be umounted anymore. Mounts are
* processed in order, newest first. The retries are needed when
* an old mount has been moved, to a path inside a newer mount. */
do {
umount_changed = false;
- r = umount_all_once(&umount_changed);
+ r = umount_all_once(&umount_changed, umount_log_level);
if (umount_changed)
*changed = true;
} while (umount_changed);
@@ -672,6 +688,8 @@ int swapoff_all(bool *changed) {
int r;
LIST_HEAD(MountPoint, swap_list_head);
+ assert(changed);
+
LIST_HEAD_INIT(swap_list_head);
r = swap_list_get(&swap_list_head);
@@ -686,17 +704,19 @@ int swapoff_all(bool *changed) {
return r;
}
-int loopback_detach_all(bool *changed) {
+int loopback_detach_all(bool *changed, int umount_log_level) {
int r;
LIST_HEAD(MountPoint, loopback_list_head);
+ assert(changed);
+
LIST_HEAD_INIT(loopback_list_head);
r = loopback_list_get(&loopback_list_head);
if (r < 0)
goto end;
- r = loopback_points_list_detach(&loopback_list_head, changed);
+ r = loopback_points_list_detach(&loopback_list_head, changed, umount_log_level);
end:
mount_points_list_free(&loopback_list_head);
@@ -704,17 +724,19 @@ int loopback_detach_all(bool *changed) {
return r;
}
-int dm_detach_all(bool *changed) {
+int dm_detach_all(bool *changed, int umount_log_level) {
int r;
LIST_HEAD(MountPoint, dm_list_head);
+ assert(changed);
+
LIST_HEAD_INIT(dm_list_head);
r = dm_list_get(&dm_list_head);
if (r < 0)
goto end;
- r = dm_points_list_detach(&dm_list_head, changed);
+ r = dm_points_list_detach(&dm_list_head, changed, umount_log_level);
end:
mount_points_list_free(&dm_list_head);
generated by cgit v1.2.2 (git 2.25.0) at 2024-05-04 16:15:28 +0000