watch mount status file

This commit is contained in:
Lennart Poettering 2010-01-29 06:04:08 +01:00
parent 38a4d4f089
commit ef734fd6c2
6 changed files with 138 additions and 57 deletions

View file

@ -36,7 +36,7 @@ static int manager_setup_signals(Manager *m) {
assert_se(sigaddset(&mask, SIGPIPE) == 0);
assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
m->signal_watch.type = WATCH_SIGNAL_FD;
m->signal_watch.type = WATCH_SIGNAL;
if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
return -errno;
@ -56,7 +56,7 @@ Manager* manager_new(void) {
if (!(m = new0(Manager, 1)))
return NULL;
m->signal_watch.fd = m->epoll_fd = -1;
m->signal_watch.fd = m->mount_watch.fd = m->epoll_fd = -1;
if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
goto fail;
@ -1123,7 +1123,7 @@ static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
switch (w->type) {
case WATCH_SIGNAL_FD:
case WATCH_SIGNAL:
/* An incoming signal? */
if (ev->events != POLLIN)
@ -1157,6 +1157,11 @@ static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
break;
}
case WATCH_MOUNT:
/* Some mount table change, intended for the mount subsystem */
mount_fd_event(m, ev->events);
break;
default:
assert_not_reached("Unknown epoll event type.");
}

View file

@ -13,9 +13,10 @@ typedef struct Watch Watch;
enum WatchType {
WATCH_INVALID,
WATCH_SIGNAL_FD,
WATCH_SIGNAL,
WATCH_FD,
WATCH_TIMER
WATCH_TIMER,
WATCH_MOUNT
};
struct Watch {
@ -48,6 +49,10 @@ struct Manager {
Hashmap *units; /* name string => Unit object n:1 */
Hashmap *jobs; /* job id => Job object 1:1 */
/* To make it easy to iterate through the units of a specific
* type we maintain a per type linked list */
LIST_HEAD(Meta, units_per_type[_UNIT_TYPE_MAX]);
/* Units that need to be loaded */
LIST_HEAD(Meta, load_queue); /* this is actually more a stack than a queue, but uh. */
@ -67,7 +72,12 @@ struct Manager {
Watch signal_watch;
/* Data specific to the device subsystem */
struct udev* udev;
/* Data specific to the mount subsystem */
FILE *proc_self_mountinfo;
Watch mount_watch;
};
Manager* manager_new(void);

148
mount.c
View file

@ -3,6 +3,8 @@
#include <errno.h>
#include <stdio.h>
#include <mntent.h>
#include <sys/epoll.h>
#include <sys/poll.h>
#include "unit.h"
#include "mount.h"
@ -27,17 +29,20 @@ static const char* const state_string_table[_MOUNT_STATE_MAX] = {
};
static void mount_done(Unit *u) {
Mount *d = MOUNT(u);
Mount *m = MOUNT(u);
assert(d);
free(d->what);
free(d->where);
assert(m);
free(m->what);
free(m->where);
}
static void mount_set_state(Mount *m, MountState state) {
MountState old_state;
assert(m);
if (state == m->state)
return;
old_state = m->state;
m->state = state;
@ -83,6 +88,10 @@ static UnitActiveState mount_active_state(Unit *u) {
}
static void mount_shutdown(Manager *m) {
assert(m);
if (m->proc_self_mountinfo)
fclose(m->proc_self_mountinfo);
}
static int mount_add_node_links(Mount *m) {
@ -119,35 +128,34 @@ static int mount_add_node_links(Mount *m) {
}
static int mount_add_path_links(Mount *m) {
Iterator i;
Unit *other;
Meta *other;
int r;
/* Adds in link to other mount points, that might lie below or
* above us in the hierarchy */
HASHMAP_FOREACH(other, UNIT(m)->meta.manager->units, i) {
LIST_FOREACH(units_per_type, other, UNIT(m)->meta.manager->units_per_type[UNIT_MOUNT]) {
Mount *n;
if (other->meta.type != UNIT_MOUNT)
continue;
n = (Mount*) other;
n = MOUNT(other);
if (n == m)
return 0;
if (path_startswith(m->where, n->where)) {
if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, other)) < 0)
if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, (Unit*) other)) < 0)
return r;
if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, other)) < 0)
if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, (Unit*) other)) < 0)
return r;
} else if (startswith(n->where, m->where)) {
if ((r = unit_add_dependency(UNIT(m), UNIT_BEFORE, other)) < 0)
if ((r = unit_add_dependency(UNIT(m), UNIT_BEFORE, (Unit*) other)) < 0)
return r;
if ((r = unit_add_dependency(other, UNIT_REQUIRES, UNIT(m))) < 0)
if ((r = unit_add_dependency((Unit*) other, UNIT_REQUIRES, UNIT(m))) < 0)
return r;
}
}
@ -155,7 +163,7 @@ static int mount_add_path_links(Mount *m) {
return 0;
}
static int mount_add_one(Manager *m, const char *what, const char *where, bool live) {
static int mount_add_one(Manager *m, const char *what, const char *where, bool live, bool set_flags) {
char *e;
int r;
Unit *u;
@ -199,15 +207,24 @@ static int mount_add_one(Manager *m, const char *what, const char *where, bool l
if ((r = unit_set_description(u, where)) < 0)
goto fail;
} else {
delete = false;
free(e);
}
if (live)
if (set_flags)
MOUNT(u)->still_exists = true;
if (live) {
if (set_flags)
MOUNT(u)->just_created = !MOUNT(u)->from_proc_self_mountinfo;
MOUNT(u)->from_proc_self_mountinfo = true;
else
} else {
if (set_flags)
MOUNT(u)->just_created = !MOUNT(u)->from_etc_fstab;
MOUNT(u)->from_etc_fstab = true;
}
if ((r = mount_add_node_links(MOUNT(u))) < 0)
goto fail;
@ -264,7 +281,7 @@ static char *fstab_node_to_udev_node(char *p) {
return strdup(p);
}
static int mount_load_etc_fstab(Manager *m) {
static int mount_load_etc_fstab(Manager *m, bool set_flags) {
FILE *f;
int r;
struct mntent* me;
@ -295,7 +312,7 @@ static int mount_load_etc_fstab(Manager *m) {
if (where[0] == '/')
path_kill_slashes(where);
r = mount_add_one(m, what, where, false);
r = mount_add_one(m, what, where, false, set_flags);
free(what);
free(where);
@ -310,20 +327,18 @@ finish:
return r;
}
static int mount_load_proc_self_mountinfo(Manager *m) {
FILE *f;
static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
int r;
assert(m);
if (!(f = fopen("/proc/self/mountinfo", "r")))
return -errno;
rewind(m->proc_self_mountinfo);
for (;;) {
int k;
char *device, *path, *d, *p;
if ((k = fscanf(f,
if ((k = fscanf(m->proc_self_mountinfo,
"%*s " /* (1) mount id */
"%*s " /* (2) parent id */
"%*s " /* (3) major:minor */
@ -333,63 +348,64 @@ static int mount_load_proc_self_mountinfo(Manager *m) {
"%*[^-]" /* (7) optional fields */
"- " /* (8) seperator */
"%*s " /* (9) file system type */
"%ms" /* (10) mount source */
"%*[^\n]", /* some rubbish at the end */
"%ms" /* (10) mount source */
"%*[^\n]", /* some rubbish at the end */
&path,
&device)) != 2) {
if (k == EOF) {
if (feof(f))
break;
if (k == EOF)
break;
r = -errno;
goto finish;
}
r = -EBADMSG;
goto finish;
return -EBADMSG;
}
if (!(d = cunescape(device))) {
free(device);
free(path);
r = -ENOMEM;
goto finish;
return -ENOMEM;
}
free(device);
if (!(p = cunescape(path))) {
free(d);
free(path);
r = -ENOMEM;
goto finish;
return -ENOMEM;
}
free(path);
r = mount_add_one(m, d, p, true);
r = mount_add_one(m, d, p, true, set_flags);
free(d);
free(p);
if (r < 0)
goto finish;
return r;
}
r = 0;
finish:
fclose(f);
return r;
return 0;
}
static int mount_enumerate(Manager *m) {
int r;
struct epoll_event ev;
assert(m);
if ((r = mount_load_etc_fstab(m)) < 0)
if (!(m->proc_self_mountinfo = fopen("/proc/self/mountinfo", "r")))
return -errno;
m->mount_watch.type = WATCH_MOUNT;
m->mount_watch.fd = fileno(m->proc_self_mountinfo);
zero(ev);
ev.events = EPOLLERR;
ev.data.ptr = &m->mount_watch;
if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->mount_watch.fd, &ev) < 0)
return -errno;
if ((r = mount_load_etc_fstab(m, false)) < 0)
goto fail;
if ((r = mount_load_proc_self_mountinfo(m)) < 0)
if ((r = mount_load_proc_self_mountinfo(m, false)) < 0)
goto fail;
return 0;
@ -399,6 +415,40 @@ fail:
return r;
}
void mount_fd_event(Manager *m, int events) {
Meta *meta;
int r;
assert(m);
assert(events == POLLERR);
/* The manager calls this for every fd event happening on the
* /proc/self/mountinfo file, which informs us about mounting
* table changes */
if ((r = mount_load_proc_self_mountinfo(m, true)) < 0) {
log_error("Failed to reread /proc/self/mountinfo: %s", strerror(-errno));
return;
}
manager_dispatch_load_queue(m);
LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_MOUNT]) {
Mount *mount = (Mount*) meta;
if (mount->just_created && mount->state == MOUNT_DEAD)
mount_set_state(mount, MOUNT_MOUNTED);
else if (!mount->still_exists && mount->state == MOUNT_MOUNTED) {
mount_set_state(mount, MOUNT_DEAD);
mount->from_proc_self_mountinfo = false;
}
/* Clear the flags for later calls */
mount->just_created = false;
mount->still_exists = false;
}
}
const UnitVTable mount_vtable = {
.suffix = ".mount",

View file

@ -25,8 +25,15 @@ struct Mount {
bool from_etc_fstab:1;
bool from_proc_self_mountinfo:1;
/* Used while looking for mount points that vanished or got
* added from/to /proc/self/mountinfo */
bool still_exists:1;
bool just_created:1;
};
extern const UnitVTable mount_vtable;
void mount_fd_event(Manager *m, int events);
#endif

6
unit.c
View file

@ -147,6 +147,9 @@ int unit_add_name(Unit *u, const char *text) {
return r;
}
if (u->meta.type == _UNIT_TYPE_INVALID)
LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
u->meta.type = t;
if (!u->meta.id)
@ -224,6 +227,9 @@ void unit_free(Unit *u) {
SET_FOREACH(t, u->meta.names, i)
hashmap_remove_value(u->meta.manager->units, t, u);
if (u->meta.type != _UNIT_TYPE_INVALID)
LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
if (u->meta.in_load_queue)
LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);

9
unit.h
View file

@ -14,14 +14,11 @@ typedef enum UnitLoadState UnitLoadState;
typedef enum UnitActiveState UnitActiveState;
typedef enum UnitDependency UnitDependency;
#include "job.h"
#include "manager.h"
#include "set.h"
#include "util.h"
#include "list.h"
#include "socket-util.h"
#include "execute.h"
#include "util.h"
#define UNIT_NAME_MAX 128
#define DEFAULT_TIMEOUT_USEC (20*USEC_PER_SEC)
@ -92,6 +89,9 @@ enum UnitDependency {
_UNIT_DEPENDENCY_INVALID = -1
};
#include "manager.h"
#include "job.h"
struct Meta {
Manager *manager;
UnitType type;
@ -116,6 +116,9 @@ struct Meta {
/* Load queue */
LIST_FIELDS(Meta, load_queue);
/* Per type list */
LIST_FIELDS(Meta, units_per_type);
};
#include "service.h"