[dm-devel] [PATCH 11/19] libmultipath: protect racy libdevmapper calls with a mutex
mwilck at suse.com
mwilck at suse.com
Wed Sep 16 15:37:10 UTC 2020
From: Martin Wilck <mwilck at suse.com>
dm_udev_wait() and dm_task_run() may access global / static state
in libdevmapper. They need to be protected by a lock in in our
multithreaded library.
Cc: lixiaokeng at huawei.com
Cc: Zdenek Kabelac <zkabelac at redhat.com>
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
libmultipath/devmapper.c | 73 +++++++++++++++++++++++++---------------
libmultipath/devmapper.h | 2 ++
libmultipath/util.c | 5 +++
libmultipath/util.h | 1 +
multipathd/dmevents.c | 2 +-
multipathd/waiter.c | 2 +-
6 files changed, 56 insertions(+), 29 deletions(-)
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 3694cc8..34f6ade 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -42,6 +42,7 @@ static unsigned int dm_mpath_target_version[3] = { INVALID_VERSION, };
static pthread_once_t dm_initialized = PTHREAD_ONCE_INIT;
static pthread_once_t versions_initialized = PTHREAD_ONCE_INIT;
+static pthread_mutex_t libmp_dm_lock = PTHREAD_MUTEX_INITIALIZER;
static int dm_conf_verbosity;
@@ -59,16 +60,34 @@ static inline int dm_task_set_cookie(struct dm_task *dmt, uint32_t *c, int a)
return 1;
}
-void dm_udev_wait(unsigned int c)
+static void libmp_udev_wait(unsigned int c)
{
}
-void dm_udev_set_sync_support(int c)
+static void dm_udev_set_sync_support(int c)
{
}
-
+#else
+static void libmp_udev_wait(unsigned int c)
+{
+ pthread_mutex_lock(&libmp_dm_lock);
+ pthread_cleanup_push(cleanup_mutex, &libmp_dm_lock);
+ dm_udev_wait(c);
+ pthread_cleanup_pop(1);
+}
#endif
+int libmp_task_run(struct dm_task *dmt)
+{
+ int r;
+
+ pthread_mutex_lock(&libmp_dm_lock);
+ pthread_cleanup_push(cleanup_mutex, &libmp_dm_lock);
+ r = dm_task_run(dmt);
+ pthread_cleanup_pop(1);
+ return r;
+}
+
__attribute__((format(printf, 4, 5))) static void
dm_write_log (int level, const char *file, int line, const char *f, ...)
{
@@ -191,7 +210,7 @@ static int dm_tgt_version (unsigned int *version, char *str)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(2, DM_DEVICE_LIST_VERSIONS, dmt);
condlog(0, "Can not communicate with kernel DM");
goto out;
@@ -375,12 +394,12 @@ dm_simplecmd (int task, const char *name, int no_flush, int need_sync, uint16_t
DM_UDEV_DISABLE_LIBRARY_FALLBACK | udev_flags))
goto out;
- r = dm_task_run (dmt);
+ r = libmp_task_run (dmt);
if (!r)
dm_log_error(2, task, dmt);
if (udev_wait_flag)
- dm_udev_wait(cookie);
+ libmp_udev_wait(cookie);
out:
dm_task_destroy (dmt);
return r;
@@ -467,12 +486,12 @@ dm_addmap (int task, const char *target, struct multipath *mpp,
!dm_task_set_cookie(dmt, &cookie, udev_flags))
goto freeout;
- r = dm_task_run (dmt);
+ r = libmp_task_run (dmt);
if (!r)
dm_log_error(2, task, dmt);
if (task == DM_DEVICE_CREATE)
- dm_udev_wait(cookie);
+ libmp_udev_wait(cookie);
freeout:
if (prefixed_uuid)
FREE(prefixed_uuid);
@@ -582,7 +601,7 @@ do_get_info(const char *name, struct dm_info *info)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_INFO, dmt);
goto out;
}
@@ -623,7 +642,7 @@ int dm_get_map(const char *name, unsigned long long *size, char *outparams)
dm_task_no_open_count(dmt);
errno = 0;
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_TABLE, dmt);
if (dm_task_get_errno(dmt) == ENXIO)
r = DMP_NOT_FOUND;
@@ -665,7 +684,7 @@ dm_get_prefixed_uuid(const char *name, char *uuid, int uuid_len)
if (!dm_task_set_name (dmt, name))
goto uuidout;
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_INFO, dmt);
goto uuidout;
}
@@ -736,7 +755,7 @@ int dm_get_status(const char *name, char *outstatus)
dm_task_no_open_count(dmt);
errno = 0;
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_STATUS, dmt);
if (dm_task_get_errno(dmt) == ENXIO)
r = DMP_NOT_FOUND;
@@ -789,7 +808,7 @@ int dm_type(const char *name, char *type)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_TABLE, dmt);
goto out;
}
@@ -833,7 +852,7 @@ int dm_is_mpath(const char *name)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_TABLE, dmt);
goto out_task;
}
@@ -897,7 +916,7 @@ dm_map_present_by_uuid(const char *uuid)
if (!dm_task_set_uuid(dmt, prefixed_uuid))
goto out_task;
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_INFO, dmt);
goto out_task;
}
@@ -943,7 +962,7 @@ dm_get_opencount (const char * mapname)
if (!dm_task_set_name(dmt, mapname))
goto out;
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_INFO, dmt);
goto out;
}
@@ -1103,7 +1122,7 @@ int dm_flush_maps (int need_suspend, int retries)
dm_task_no_open_count(dmt);
- if (!dm_task_run (dmt)) {
+ if (!libmp_task_run (dmt)) {
dm_log_error(3, DM_DEVICE_LIST, dmt);
goto out;
}
@@ -1149,7 +1168,7 @@ dm_message(const char * mapname, char * message)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(2, DM_DEVICE_TARGET_MSG, dmt);
goto out;
}
@@ -1269,7 +1288,7 @@ dm_get_maps (vector mp)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_LIST, dmt);
goto out;
}
@@ -1354,7 +1373,7 @@ dm_mapname(int major, int minor)
* daemon uev_trigger -> uev_add_map
*/
while (--loop) {
- r = dm_task_run(dmt);
+ r = libmp_task_run(dmt);
if (r)
break;
@@ -1399,7 +1418,7 @@ do_foreach_partmaps (const char * mapname,
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_LIST, dmt);
goto out;
}
@@ -1634,11 +1653,11 @@ dm_rename (const char * old, char * new, char *delim, int skip_kpartx)
if (!dm_task_set_cookie(dmt, &cookie, udev_flags))
goto out;
- r = dm_task_run(dmt);
+ r = libmp_task_run(dmt);
if (!r)
dm_log_error(2, DM_DEVICE_RENAME, dmt);
- dm_udev_wait(cookie);
+ libmp_udev_wait(cookie);
out:
dm_task_destroy(dmt);
@@ -1680,7 +1699,7 @@ int dm_reassign_table(const char *name, char *old, char *new)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_TABLE, dmt);
goto out;
}
@@ -1713,7 +1732,7 @@ int dm_reassign_table(const char *name, char *old, char *new)
if (modified) {
dm_task_no_open_count(reload_dmt);
- if (!dm_task_run(reload_dmt)) {
+ if (!libmp_task_run(reload_dmt)) {
dm_log_error(3, DM_DEVICE_RELOAD, reload_dmt);
condlog(3, "%s: failed to reassign targets", name);
goto out_reload;
@@ -1760,7 +1779,7 @@ int dm_reassign(const char *mapname)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_DEPS, dmt);
goto out;
}
@@ -1828,7 +1847,7 @@ int dm_setgeometry(struct multipath *mpp)
goto out;
}
- r = dm_task_run(dmt);
+ r = libmp_task_run(dmt);
if (!r)
dm_log_error(3, DM_DEVICE_SET_GEOMETRY, dmt);
out:
diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
index c8b37e1..75fbc33 100644
--- a/libmultipath/devmapper.h
+++ b/libmultipath/devmapper.h
@@ -89,6 +89,8 @@ enum {
MULTIPATH_VERSION
};
int libmp_get_version(int which, unsigned int version[3]);
+struct dm_task;
+int libmp_task_run(struct dm_task *dmt);
#define dm_log_error(lvl, cmd, dmt) \
condlog(lvl, "%s: libdm task=%d error: %s", __func__, \
diff --git a/libmultipath/util.c b/libmultipath/util.c
index 7a0b2eb..8412d30 100644
--- a/libmultipath/util.c
+++ b/libmultipath/util.c
@@ -401,6 +401,11 @@ void close_fd(void *arg)
close((long)arg);
}
+void cleanup_mutex(void *arg)
+{
+ pthread_mutex_unlock(arg);
+}
+
struct bitfield *alloc_bitfield(unsigned int maxbit)
{
unsigned int n;
diff --git a/libmultipath/util.h b/libmultipath/util.h
index a0d3d50..94ed872 100644
--- a/libmultipath/util.h
+++ b/libmultipath/util.h
@@ -48,6 +48,7 @@ int should_exit(void);
pthread_cleanup_push(((void (*)(void *))&f), (arg))
void close_fd(void *arg);
+void cleanup_mutex(void *arg);
struct scandir_result {
struct dirent **di;
diff --git a/multipathd/dmevents.c b/multipathd/dmevents.c
index fc97c8a..f8ed4e4 100644
--- a/multipathd/dmevents.c
+++ b/multipathd/dmevents.c
@@ -156,7 +156,7 @@ static int dm_get_events(void)
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt)) {
+ if (!libmp_task_run(dmt)) {
dm_log_error(3, DM_DEVICE_LIST, dmt);
goto fail;
}
diff --git a/multipathd/waiter.c b/multipathd/waiter.c
index 16fbdc8..ef57765 100644
--- a/multipathd/waiter.c
+++ b/multipathd/waiter.c
@@ -118,7 +118,7 @@ static int waiteventloop (struct event_thread *waiter)
pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
pthread_testcancel();
- r = dm_task_run(waiter->dmt);
+ r = libmp_task_run(waiter->dmt);
if (!r)
dm_log_error(2, DM_DEVICE_WAITEVENT, waiter->dmt);
pthread_testcancel();
--
2.28.0
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