Reply to the app on errors to prevent an app-side receive hang.
Signed-off-by: Jonathan Rajotte <[email protected]>
---
src/bin/lttng-sessiond/ust-app.c | 64 ++++++++++++++++++++++------------------
1 file changed, 36 insertions(+), 28 deletions(-)
diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index e79455b0..20ac469b 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -5394,13 +5394,13 @@ static int reply_ust_register_channel(int sock, int
sobjd, int cobjd,
size_t nr_fields, struct ustctl_field *fields)
{
int ret, ret_code = 0;
- uint32_t chan_id, reg_count;
- uint64_t chan_reg_key;
- enum ustctl_channel_header type;
+ uint32_t chan_id = 0, reg_count = 0;
+ uint64_t chan_reg_key = 0;
+ enum ustctl_channel_header type = USTCTL_CHANNEL_HEADER_UNKNOWN;
struct ust_app *app;
struct ust_app_channel *ua_chan;
struct ust_app_session *ua_sess;
- struct ust_registry_session *registry;
+ struct ust_registry_session *registry = NULL;
struct ust_registry_channel *chan_reg;
rcu_read_lock();
@@ -5410,16 +5410,16 @@ static int reply_ust_register_channel(int sock, int
sobjd, int cobjd,
if (!app) {
DBG("Application socket %d is being torn down. Abort event
notify",
sock);
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
/* Lookup channel by UST object descriptor. */
ua_chan = find_channel_by_objd(app, cobjd);
if (!ua_chan) {
DBG("Application channel is being torn down. Abort event
notify");
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
assert(ua_chan->session);
@@ -5429,8 +5429,8 @@ static int reply_ust_register_channel(int sock, int
sobjd, int cobjd,
registry = get_session_registry(ua_sess);
if (!registry) {
DBG("Application session is being torn down. Abort event
notify");
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
};
/* Depending on the buffer type, a different channel key is used. */
@@ -5469,10 +5469,13 @@ static int reply_ust_register_channel(int sock, int
sobjd, int cobjd,
ret_code = ust_metadata_channel_statedump(registry, chan_reg);
if (ret_code) {
ERR("Error appending channel metadata (errno = %d)",
ret_code);
- goto reply;
+ goto unlock_reply;
}
}
+unlock_reply:
+ pthread_mutex_unlock(®istry->lock);
+
reply:
DBG3("UST app replying to register channel key %" PRIu64
" with id %u, type: %d, ret: %d", chan_reg_key,
chan_id, type,
@@ -5488,12 +5491,13 @@ reply:
goto error;
}
- /* This channel registry registration is completed. */
+ if (ret_code < 0) {
+ goto error;
+ }
+
chan_reg->register_done = 1;
error:
- pthread_mutex_unlock(®istry->lock);
-error_rcu_unlock:
rcu_read_unlock();
free(fields);
return ret;
@@ -5527,16 +5531,16 @@ static int add_event_ust_registry(int sock, int sobjd,
int cobjd, char *name,
if (!app) {
DBG("Application socket %d is being torn down. Abort event
notify",
sock);
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
/* Lookup channel by UST object descriptor. */
ua_chan = find_channel_by_objd(app, cobjd);
if (!ua_chan) {
DBG("Application channel is being torn down. Abort event
notify");
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
assert(ua_chan->session);
@@ -5545,8 +5549,8 @@ static int add_event_ust_registry(int sock, int sobjd,
int cobjd, char *name,
registry = get_session_registry(ua_sess);
if (!registry) {
DBG("Application session is being torn down. Abort event
notify");
- ret = 0;
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
@@ -5570,6 +5574,9 @@ static int add_event_ust_registry(int sock, int sobjd,
int cobjd, char *name,
fields = NULL;
model_emf_uri = NULL;
+ pthread_mutex_unlock(®istry->lock);
+
+reply:
/*
* The return value is returned to ustctl so in case of an error, the
* application can be notified. In case of an error, it's important not
to
@@ -5593,8 +5600,6 @@ static int add_event_ust_registry(int sock, int sobjd,
int cobjd, char *name,
name, event_id);
error:
- pthread_mutex_unlock(®istry->lock);
-error_rcu_unlock:
rcu_read_unlock();
free(sig);
free(fields);
@@ -5627,8 +5632,9 @@ static int add_enum_ust_registry(int sock, int sobjd,
char *name,
/* Return an error since this is not an error */
DBG("Application socket %d is being torn down. Aborting enum
registration",
sock);
+ ret_code = -1;
free(entries);
- goto error_rcu_unlock;
+ goto reply;
}
/* Lookup session by UST object descriptor. */
@@ -5637,14 +5643,16 @@ static int add_enum_ust_registry(int sock, int sobjd,
char *name,
/* Return an error since this is not an error */
DBG("Application session is being torn down (session not
found). Aborting enum registration.");
free(entries);
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
registry = get_session_registry(ua_sess);
if (!registry) {
DBG("Application session is being torn down (registry not
found). Aborting enum registration.");
free(entries);
- goto error_rcu_unlock;
+ ret_code = -1;
+ goto reply;
}
pthread_mutex_lock(®istry->lock);
@@ -5658,6 +5666,9 @@ static int add_enum_ust_registry(int sock, int sobjd,
char *name,
entries, nr_entries, &enum_id);
entries = NULL;
+ pthread_mutex_unlock(®istry->lock);
+
+reply:
/*
* The return value is returned to ustctl so in case of an error, the
* application can be notified. In case of an error, it's important not
to
@@ -5678,10 +5689,7 @@ static int add_enum_ust_registry(int sock, int sobjd,
char *name,
}
DBG3("UST registry enum %s added successfully or already found", name);
-
error:
- pthread_mutex_unlock(®istry->lock);
-error_rcu_unlock:
rcu_read_unlock();
return ret;
}
--
2.11.0
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