From: Alexander Aring aahringo@redhat.com
[ Upstream commit e125fbeb538e5e35a00c6c8150a5361bef34814c ]
This patch fixes an deadlock issue when dlm_lowcomms_close() is called. When dlm_lowcomms_close() is called the clusters_root.subsys.su_mutex is held to remove configfs items. At this time we flushing (e.g. cancel_work_sync()) the workers of send and recv workqueue. Due the fact that we accessing configfs items (mark values), these workers will lock clusters_root.subsys.su_mutex as well which are already hold by dlm_lowcomms_close() and ends in a deadlock situation.
[67170.703046] ====================================================== [67170.703965] WARNING: possible circular locking dependency detected [67170.704758] 5.11.0-rc4+ #22 Tainted: G W [67170.705433] ------------------------------------------------------ [67170.706228] dlm_controld/280 is trying to acquire lock: [67170.706915] ffff9f2f475a6948 ((wq_completion)dlm_recv){+.+.}-{0:0}, at: __flush_work+0x203/0x4c0 [67170.708026] but task is already holding lock: [67170.708758] ffffffffa132f878 (&clusters_root.subsys.su_mutex){+.+.}-{3:3}, at: configfs_rmdir+0x29b/0x310 [67170.710016] which lock already depends on the new lock.
The new behaviour adds the mark value to the node address configuration which doesn't require to held the clusters_root.subsys.su_mutex by accessing mark values in a separate datastructure. However the mark values can be set now only after a node address was set which is the case when the user is using dlm_controld.
Signed-off-by: Alexander Aring aahringo@redhat.com Signed-off-by: David Teigland teigland@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/dlm/config.c | 29 ++++++++++------------------ fs/dlm/config.h | 1 - fs/dlm/lowcomms.c | 49 ++++++++++++++++++++++++++++++++--------------- fs/dlm/lowcomms.h | 1 + 4 files changed, 45 insertions(+), 35 deletions(-)
diff --git a/fs/dlm/config.c b/fs/dlm/config.c index 49c5f9407098..582bffa09a66 100644 --- a/fs/dlm/config.c +++ b/fs/dlm/config.c @@ -688,6 +688,7 @@ static ssize_t comm_mark_show(struct config_item *item, char *buf) static ssize_t comm_mark_store(struct config_item *item, const char *buf, size_t len) { + struct dlm_comm *comm; unsigned int mark; int rc;
@@ -695,7 +696,15 @@ static ssize_t comm_mark_store(struct config_item *item, const char *buf, if (rc) return rc;
- config_item_to_comm(item)->mark = mark; + if (mark == 0) + mark = dlm_config.ci_mark; + + comm = config_item_to_comm(item); + rc = dlm_lowcomms_nodes_set_mark(comm->nodeid, mark); + if (rc) + return rc; + + comm->mark = mark; return len; }
@@ -870,24 +879,6 @@ int dlm_comm_seq(int nodeid, uint32_t *seq) return 0; }
-void dlm_comm_mark(int nodeid, unsigned int *mark) -{ - struct dlm_comm *cm; - - cm = get_comm(nodeid); - if (!cm) { - *mark = dlm_config.ci_mark; - return; - } - - if (cm->mark) - *mark = cm->mark; - else - *mark = dlm_config.ci_mark; - - put_comm(cm); -} - int dlm_our_nodeid(void) { return local_comm ? local_comm->nodeid : 0; diff --git a/fs/dlm/config.h b/fs/dlm/config.h index c210250a2581..d2cd4bd20313 100644 --- a/fs/dlm/config.h +++ b/fs/dlm/config.h @@ -48,7 +48,6 @@ void dlm_config_exit(void); int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out, int *count_out); int dlm_comm_seq(int nodeid, uint32_t *seq); -void dlm_comm_mark(int nodeid, unsigned int *mark); int dlm_our_nodeid(void); int dlm_our_addr(struct sockaddr_storage *addr, int num);
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 372c34ff8594..440dce99d0d9 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -116,6 +116,7 @@ struct writequeue_entry { struct dlm_node_addr { struct list_head list; int nodeid; + int mark; int addr_count; int curr_addr_index; struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; @@ -303,7 +304,8 @@ static int addr_compare(const struct sockaddr_storage *x, }
static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, - struct sockaddr *sa_out, bool try_new_addr) + struct sockaddr *sa_out, bool try_new_addr, + unsigned int *mark) { struct sockaddr_storage sas; struct dlm_node_addr *na; @@ -331,6 +333,8 @@ static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, if (!na->addr_count) return -ENOENT;
+ *mark = na->mark; + if (sas_out) memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
@@ -350,7 +354,8 @@ static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, return 0; }
-static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) +static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid, + unsigned int *mark) { struct dlm_node_addr *na; int rv = -EEXIST; @@ -364,6 +369,7 @@ static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) for (addr_i = 0; addr_i < na->addr_count; addr_i++) { if (addr_compare(na->addr[addr_i], addr)) { *nodeid = na->nodeid; + *mark = na->mark; rv = 0; goto unlock; } @@ -412,6 +418,7 @@ int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) new_node->nodeid = nodeid; new_node->addr[0] = new_addr; new_node->addr_count = 1; + new_node->mark = dlm_config.ci_mark; list_add(&new_node->list, &dlm_node_addrs); spin_unlock(&dlm_node_addrs_spin); return 0; @@ -519,6 +526,23 @@ int dlm_lowcomms_connect_node(int nodeid) return 0; }
+int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark) +{ + struct dlm_node_addr *na; + + spin_lock(&dlm_node_addrs_spin); + na = find_node_addr(nodeid); + if (!na) { + spin_unlock(&dlm_node_addrs_spin); + return -ENOENT; + } + + na->mark = mark; + spin_unlock(&dlm_node_addrs_spin); + + return 0; +} + static void lowcomms_error_report(struct sock *sk) { struct connection *con; @@ -867,7 +891,7 @@ static int accept_from_sock(struct listen_connection *con)
/* Get the new node's NODEID */ make_sockaddr(&peeraddr, 0, &len); - if (addr_to_nodeid(&peeraddr, &nodeid)) { + if (addr_to_nodeid(&peeraddr, &nodeid, &mark)) { unsigned char *b=(unsigned char *)&peeraddr; log_print("connect from non cluster node"); print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, @@ -876,9 +900,6 @@ static int accept_from_sock(struct listen_connection *con) return -1; }
- dlm_comm_mark(nodeid, &mark); - sock_set_mark(newsock->sk, mark); - log_print("got connection from %d", nodeid);
/* Check to see if we already have a connection to this node. This @@ -892,6 +913,8 @@ static int accept_from_sock(struct listen_connection *con) goto accept_err; }
+ sock_set_mark(newsock->sk, mark); + mutex_lock(&newcon->sock_mutex); if (newcon->sock) { struct connection *othercon = newcon->othercon; @@ -1015,8 +1038,6 @@ static void sctp_connect_to_sock(struct connection *con) struct socket *sock; unsigned int mark;
- dlm_comm_mark(con->nodeid, &mark); - mutex_lock(&con->sock_mutex);
/* Some odd races can cause double-connects, ignore them */ @@ -1029,7 +1050,7 @@ static void sctp_connect_to_sock(struct connection *con) }
memset(&daddr, 0, sizeof(daddr)); - result = nodeid_to_addr(con->nodeid, &daddr, NULL, true); + result = nodeid_to_addr(con->nodeid, &daddr, NULL, true, &mark); if (result < 0) { log_print("no address for nodeid %d", con->nodeid); goto out; @@ -1104,13 +1125,11 @@ static void sctp_connect_to_sock(struct connection *con) static void tcp_connect_to_sock(struct connection *con) { struct sockaddr_storage saddr, src_addr; + unsigned int mark; int addr_len; struct socket *sock = NULL; - unsigned int mark; int result;
- dlm_comm_mark(con->nodeid, &mark); - mutex_lock(&con->sock_mutex); if (con->retries++ > MAX_CONNECT_RETRIES) goto out; @@ -1125,15 +1144,15 @@ static void tcp_connect_to_sock(struct connection *con) if (result < 0) goto out_err;
- sock_set_mark(sock->sk, mark); - memset(&saddr, 0, sizeof(saddr)); - result = nodeid_to_addr(con->nodeid, &saddr, NULL, false); + result = nodeid_to_addr(con->nodeid, &saddr, NULL, false, &mark); if (result < 0) { log_print("no address for nodeid %d", con->nodeid); goto out_err; }
+ sock_set_mark(sock->sk, mark); + add_sock(sock, con);
/* Bind to our cluster-known address connecting to avoid diff --git a/fs/dlm/lowcomms.h b/fs/dlm/lowcomms.h index 0918f9376489..790d6703b17e 100644 --- a/fs/dlm/lowcomms.h +++ b/fs/dlm/lowcomms.h @@ -21,6 +21,7 @@ int dlm_lowcomms_close(int nodeid); void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc); void dlm_lowcomms_commit_buffer(void *mh); int dlm_lowcomms_connect_node(int nodeid); +int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark); int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len);
#endif /* __LOWCOMMS_DOT_H__ */