picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Merge pull request #7940 from sourcejedi/mount

Browse source 
mount rationalization
This commit is contained in:
Lennart Poettering 2018-01-23 13:45:24 +01:00 committed by GitHub
parent 10a0f27bfd b6ba0c164d
commit e69b29a8b9
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
5 changed files with 38 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
src/core/automount.c
View file

@ -578,7 +578,7 @@ static void automount_enter_waiting(Automount *a) {
set_clear(a->tokens);
r = unit_fail_if_symlink(UNIT(a), a->where);
r = unit_fail_if_noncanonical(UNIT(a), a->where);
if (r < 0)
goto fail;

48
src/core/mount.c
View file

@ -55,7 +55,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_iter*, mnt_free_iter);
static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = {
[MOUNT_DEAD] = UNIT_INACTIVE,
[MOUNT_MOUNTING] = UNIT_ACTIVATING,
[MOUNT_MOUNTING_DONE] = UNIT_ACTIVE,
[MOUNT_MOUNTING_DONE] = UNIT_ACTIVATING,
[MOUNT_MOUNTED] = UNIT_ACTIVE,
[MOUNT_REMOUNTING] = UNIT_RELOADING,
[MOUNT_UNMOUNTING] = UNIT_DEACTIVATING,
@ -942,7 +942,7 @@ static void mount_enter_mounting(Mount *m) {
assert(m);
r = unit_fail_if_symlink(UNIT(m), m->where);
r = unit_fail_if_noncanonical(UNIT(m), m->where);
if (r < 0)
goto fail;
@ -1135,10 +1135,6 @@ static int mount_reload(Unit *u) {
Mount *m = MOUNT(u);
assert(m);
if (m->state == MOUNT_MOUNTING_DONE) /* not yet ready to reload, try again */
return -EAGAIN;
assert(m->state == MOUNT_MOUNTED);
mount_enter_remounting(m);
@ -1280,23 +1276,25 @@ static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) {
log_unit_full(u, f == MOUNT_SUCCESS ? LOG_DEBUG : LOG_NOTICE, 0,
"Mount process exited, code=%s status=%i", sigchld_code_to_string(code), status);
/* Note that mount(8) returning and the kernel sending us a mount table change event might happen
* out-of-order. If an operation succeed we assume the kernel will follow soon too and already change into the
* resulting state. If it fails we check if the kernel still knows about the mount. and change state
* accordingly. */
/* Note that due to the io event priority logic, we can be sure the new mountinfo is loaded
* before we process the SIGCHLD for the mount command. */
switch (m->state) {
case MOUNT_MOUNTING:
case MOUNT_MOUNTING_DONE:
/* Our mount point has not appeared in mountinfo. Something went wrong. */
if (f == MOUNT_SUCCESS || m->from_proc_self_mountinfo)
/* If /bin/mount returned success, or if we see the mount point in /proc/self/mountinfo we are
* happy. If we see the first condition first, we should see the second condition
* immediately after – or /bin/mount lies to us and is broken. */
mount_enter_mounted(m, f);
else
mount_enter_dead(m, f);
if (f == MOUNT_SUCCESS) {
/* Either /bin/mount has an unexpected definition of success,
* or someone raced us and we lost. */
log_unit_warning(UNIT(m), "Mount process finished, but there is no mount.");
f = MOUNT_FAILURE_PROTOCOL;
}
mount_enter_dead(m, f);
break;
case MOUNT_MOUNTING_DONE:
mount_enter_mounted(m, f);
break;
case MOUNT_REMOUNTING:
@ -1306,21 +1304,19 @@ static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) {
break;
case MOUNT_UNMOUNTING:
case MOUNT_UNMOUNTING_SIGKILL:
case MOUNT_UNMOUNTING_SIGTERM:
if (f == MOUNT_SUCCESS && m->from_proc_self_mountinfo) {
/* Still a mount point? If so, let's try again. Most likely there were multiple mount points
* stacked on top of each other. Note that due to the io event priority logic we can be sure
* the new mountinfo is loaded before we process the SIGCHLD for the mount command. */
* stacked on top of each other. We might exceed the timeout specified by the user overall,
* but we will stop as soon as any one umount times out. */
if (m->n_retry_umount < RETRY_UMOUNT_MAX) {
log_unit_debug(u, "Mount still present, trying again.");
m->n_retry_umount++;
mount_enter_unmounting(m);
} else {
log_unit_debug(u, "Mount still present after %u attempts to unmount, giving up.", m->n_retry_umount);
log_unit_warning(u, "Mount still present after %u attempts to unmount, giving up.", m->n_retry_umount);
mount_enter_mounted(m, f);
}
} else
@ -1328,6 +1324,11 @@ static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) {
break;
case MOUNT_UNMOUNTING_SIGKILL:
case MOUNT_UNMOUNTING_SIGTERM:
mount_enter_dead_or_mounted(m, f);
break;
default:
assert_not_reached("Uh, control process died at wrong time.");
}
@ -1951,6 +1952,7 @@ static const char* const mount_result_table[_MOUNT_RESULT_MAX] = {
[MOUNT_FAILURE_SIGNAL] = "signal",
[MOUNT_FAILURE_CORE_DUMP] = "core-dump",
[MOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
[MOUNT_FAILURE_PROTOCOL] = "protocol",
};
DEFINE_STRING_TABLE_LOOKUP(mount_result, MountResult);

3
src/core/mount.h
View file

@ -35,12 +35,13 @@ typedef enum MountExecCommand {
typedef enum MountResult {
MOUNT_SUCCESS,
MOUNT_FAILURE_RESOURCES,
MOUNT_FAILURE_RESOURCES, /* a bit of a misnomer, just our catch-all error for errnos we didn't expect */
MOUNT_FAILURE_TIMEOUT,
MOUNT_FAILURE_EXIT_CODE,
MOUNT_FAILURE_SIGNAL,
MOUNT_FAILURE_CORE_DUMP,
MOUNT_FAILURE_START_LIMIT_HIT,
MOUNT_FAILURE_PROTOCOL,
_MOUNT_RESULT_MAX,
_MOUNT_RESULT_INVALID = -1
} MountResult;

14
src/core/unit.c
View file

@ -4705,25 +4705,29 @@ void unit_warn_if_dir_nonempty(Unit *u, const char* where) {
NULL);
}
int unit_fail_if_symlink(Unit *u, const char* where) {
int unit_fail_if_noncanonical(Unit *u, const char* where) {
_cleanup_free_ char *canonical_where;
int r;
assert(u);
assert(where);
r = is_symlink(where);
r = chase_symlinks(where, NULL, CHASE_NONEXISTENT, &canonical_where);
if (r < 0) {
log_unit_debug_errno(u, r, "Failed to check symlink %s, ignoring: %m", where);
log_unit_debug_errno(u, r, "Failed to check %s for symlinks, ignoring: %m", where);
return 0;
}
if (r == 0)
/* We will happily ignore a trailing slash (or any redundant slashes) */
if (path_equal(where, canonical_where))
return 0;
/* No need to mention "." or "..", they would already have been rejected by unit_name_from_path() */
log_struct(LOG_ERR,
"MESSAGE_ID=" SD_MESSAGE_OVERMOUNTING_STR,
LOG_UNIT_ID(u),
LOG_UNIT_INVOCATION_ID(u),
LOG_UNIT_MESSAGE(u, "Mount on symlink %s not allowed.", where),
LOG_UNIT_MESSAGE(u, "Mount path %s is not canonical (contains a symlink).", where),
"WHERE=%s", where,
NULL);

2
src/core/unit.h
View file

@ -760,7 +760,7 @@ static inline bool unit_supported(Unit *u) {
}
void unit_warn_if_dir_nonempty(Unit *u, const char* where);
int unit_fail_if_symlink(Unit *u, const char* where);
int unit_fail_if_noncanonical(Unit *u, const char* where);
int unit_start_limit_test(Unit *u);