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McKenney" , Breno Leitao , Corey Minyard , Corey Minyard Subject: [PATCH 07/23] ipmi:msghandler: Remove srcu from the ipmi user structure Date: Thu, 24 Apr 2025 11:49:44 -0500 Message-ID: <20250424165020.627193-8-corey@minyard.net> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250424165020.627193-1-corey@minyard.net> References: <20250424165020.627193-1-corey@minyard.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With the restructures done, srcu is no longer required, and it's fairly onerous. Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 310 ++++++++++++---------------- 1 file changed, 133 insertions(+), 177 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index c060be93562d..7dd264e40957 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -180,14 +180,8 @@ MODULE_PARM_DESC(max_msgs_per_user, struct ipmi_user { struct list_head link; - /* - * Set to NULL when the user is destroyed, a pointer to myself - * so srcu_dereference can be used on it. - */ - struct ipmi_user *self; - struct srcu_struct release_barrier; - struct kref refcount; + refcount_t destroyed; /* The upper layer that handles receive messages. */ const struct ipmi_user_hndl *handler; @@ -200,28 +194,25 @@ struct ipmi_user { bool gets_events; atomic_t nr_msgs; - - /* Free must run in process context for RCU cleanup. */ - struct work_struct remove_work; }; -static struct workqueue_struct *remove_work_wq; - -static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user, int *index) - __acquires(user->release_barrier) +static void free_ipmi_user(struct kref *ref) { - struct ipmi_user *ruser; + struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); - *index = srcu_read_lock(&user->release_barrier); - ruser = srcu_dereference(user->self, &user->release_barrier); - if (!ruser) - srcu_read_unlock(&user->release_barrier, *index); - return ruser; + vfree(user); } -static void release_ipmi_user(struct ipmi_user *user, int index) +static void release_ipmi_user(struct ipmi_user *user) { - srcu_read_unlock(&user->release_barrier, index); + kref_put(&user->refcount, free_ipmi_user); +} + +static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user) +{ + if (!kref_get_unless_zero(&user->refcount)) + return NULL; + return user; } struct cmd_rcvr { @@ -327,6 +318,8 @@ struct bmc_device { }; #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev) +static struct workqueue_struct *bmc_remove_work_wq; + static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc, struct ipmi_device_id *id, bool *guid_set, guid_t *guid); @@ -451,11 +444,10 @@ struct ipmi_smi { struct list_head link; /* - * The list of upper layers that are using me. seq_lock write - * protects this. Read protection is with srcu. + * The list of upper layers that are using me. */ struct list_head users; - struct srcu_struct users_srcu; + struct mutex users_mutex; atomic_t nr_users; struct device_attribute nr_users_devattr; struct device_attribute nr_msgs_devattr; @@ -502,10 +494,11 @@ struct ipmi_smi { struct list_head user_msgs; /* - * Messages queued for delivery. If delivery fails (out of memory - * for instance), They will stay in here to be processed later in a - * periodic timer interrupt. The workqueue is for handling received - * messages directly from the handler. + * Messages queued for processing. If processing fails (out + * of memory for instance), They will stay in here to be + * processed later in a periodic timer interrupt. The + * workqueue is for handling received messages directly from + * the handler. */ spinlock_t waiting_rcv_msgs_lock; struct list_head waiting_rcv_msgs; @@ -635,8 +628,6 @@ static DEFINE_MUTEX(ipmidriver_mutex); static LIST_HEAD(ipmi_interfaces); static DEFINE_MUTEX(ipmi_interfaces_mutex); -#define ipmi_interfaces_mutex_held() \ - lockdep_is_held(&ipmi_interfaces_mutex) static struct srcu_struct ipmi_interfaces_srcu; /* @@ -710,13 +701,14 @@ static void clean_up_interface_data(struct ipmi_smi *intf) struct list_head list; cancel_work_sync(&intf->smi_work); + /* smi_work() can no longer be in progress after this. */ free_smi_msg_list(&intf->waiting_rcv_msgs); free_recv_msg_list(&intf->waiting_events); /* * Wholesale remove all the entries from the list in the - * interface and wait for RCU to know that none are in use. + * interface. */ mutex_lock(&intf->cmd_rcvrs_mutex); INIT_LIST_HEAD(&list); @@ -760,7 +752,7 @@ int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher) index = srcu_read_lock(&ipmi_interfaces_srcu); list_for_each_entry_rcu(intf, &ipmi_interfaces, link, - lockdep_is_held(&smi_watchers_mutex)) { + lockdep_is_held(&smi_watchers_mutex)) { int intf_num = READ_ONCE(intf->intf_num); if (intf_num == -1) @@ -784,9 +776,6 @@ int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher) } EXPORT_SYMBOL(ipmi_smi_watcher_unregister); -/* - * Must be called with smi_watchers_mutex held. - */ static void call_smi_watchers(int i, struct device *dev) { @@ -946,17 +935,15 @@ static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg) ipmi_free_recv_msg(msg); atomic_dec(&msg->user->nr_msgs); } else { - int index; - struct ipmi_user *user = acquire_ipmi_user(msg->user, &index); + struct ipmi_user *user = acquire_ipmi_user(msg->user); if (user) { /* Deliver it in smi_work. */ - kref_get(&user->refcount); mutex_lock(&intf->user_msgs_mutex); list_add_tail(&msg->link, &intf->user_msgs); mutex_unlock(&intf->user_msgs_mutex); - release_ipmi_user(user, index); queue_work(system_wq, &intf->smi_work); + /* User release will happen in the work queue. */ } else { /* User went away, give up. */ ipmi_free_recv_msg(msg); @@ -1201,22 +1188,13 @@ static int intf_err_seq(struct ipmi_smi *intf, return rv; } -static void free_user_work(struct work_struct *work) -{ - struct ipmi_user *user = container_of(work, struct ipmi_user, - remove_work); - - cleanup_srcu_struct(&user->release_barrier); - vfree(user); -} - int ipmi_create_user(unsigned int if_num, const struct ipmi_user_hndl *handler, void *handler_data, struct ipmi_user **user) { unsigned long flags; - struct ipmi_user *new_user; + struct ipmi_user *new_user = NULL; int rv, index; struct ipmi_smi *intf; @@ -1239,10 +1217,6 @@ int ipmi_create_user(unsigned int if_num, if (rv) return rv; - new_user = vzalloc(sizeof(*new_user)); - if (!new_user) - return -ENOMEM; - index = srcu_read_lock(&ipmi_interfaces_srcu); list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { if (intf->intf_num == if_num) @@ -1253,16 +1227,21 @@ int ipmi_create_user(unsigned int if_num, goto out_kfree; found: + if (intf->in_shutdown) { + rv = -ENODEV; + goto out_kfree; + } + if (atomic_add_return(1, &intf->nr_users) > max_users) { rv = -EBUSY; goto out_kfree; } - INIT_WORK(&new_user->remove_work, free_user_work); - - rv = init_srcu_struct(&new_user->release_barrier); - if (rv) + new_user = vzalloc(sizeof(*new_user)); + if (!new_user) { + rv = -ENOMEM; goto out_kfree; + } if (!try_module_get(intf->owner)) { rv = -ENODEV; @@ -1274,14 +1253,15 @@ int ipmi_create_user(unsigned int if_num, atomic_set(&new_user->nr_msgs, 0); kref_init(&new_user->refcount); + refcount_set(&new_user->destroyed, 1); + kref_get(&new_user->refcount); /* Destroy owns a refcount. */ new_user->handler = handler; new_user->handler_data = handler_data; new_user->intf = intf; new_user->gets_events = false; - rcu_assign_pointer(new_user->self, new_user); spin_lock_irqsave(&intf->seq_lock, flags); - list_add_rcu(&new_user->link, &intf->users); + list_add(&new_user->link, &intf->users); spin_unlock_irqrestore(&intf->seq_lock, flags); if (handler->ipmi_watchdog_pretimeout) /* User wants pretimeouts, so make sure to watch for them. */ @@ -1324,14 +1304,7 @@ int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data) } EXPORT_SYMBOL(ipmi_get_smi_info); -static void free_user(struct kref *ref) -{ - struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); - - /* SRCU cleanup must happen in workqueue context. */ - queue_work(remove_work_wq, &user->remove_work); -} - +/* Must be called with intf->users_mutex held. */ static void _ipmi_destroy_user(struct ipmi_user *user) { struct ipmi_smi *intf = user->intf; @@ -1341,19 +1314,8 @@ static void _ipmi_destroy_user(struct ipmi_user *user) struct cmd_rcvr *rcvrs = NULL; struct module *owner; - if (!acquire_ipmi_user(user, &i)) { - /* - * The user has already been cleaned up, just make sure - * nothing is using it and return. - */ - synchronize_srcu(&user->release_barrier); + if (!refcount_dec_if_one(&user->destroyed)) return; - } - - rcu_assign_pointer(user->self, NULL); - release_ipmi_user(user, i); - - synchronize_srcu(&user->release_barrier); if (user->handler->shutdown) user->handler->shutdown(user->handler_data); @@ -1364,11 +1326,11 @@ static void _ipmi_destroy_user(struct ipmi_user *user) if (user->gets_events) atomic_dec(&intf->event_waiters); - /* Remove the user from the interface's sequence table. */ - spin_lock_irqsave(&intf->seq_lock, flags); - list_del_rcu(&user->link); + /* Remove the user from the interface's list and sequence table. */ + list_del(&user->link); atomic_dec(&intf->nr_users); + spin_lock_irqsave(&intf->seq_lock, flags); for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) { if (intf->seq_table[i].inuse && (intf->seq_table[i].recv_msg->user == user)) { @@ -1402,6 +1364,8 @@ static void _ipmi_destroy_user(struct ipmi_user *user) kfree(rcvr); } + release_ipmi_user(user); + owner = intf->owner; kref_put(&intf->refcount, intf_free); module_put(owner); @@ -1409,9 +1373,13 @@ static void _ipmi_destroy_user(struct ipmi_user *user) void ipmi_destroy_user(struct ipmi_user *user) { + struct ipmi_smi *intf = user->intf; + + mutex_lock(&intf->users_mutex); _ipmi_destroy_user(user); + mutex_unlock(&intf->users_mutex); - kref_put(&user->refcount, free_user); + kref_put(&user->refcount, free_ipmi_user); } EXPORT_SYMBOL(ipmi_destroy_user); @@ -1420,9 +1388,9 @@ int ipmi_get_version(struct ipmi_user *user, unsigned char *minor) { struct ipmi_device_id id; - int rv, index; + int rv; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1431,7 +1399,7 @@ int ipmi_get_version(struct ipmi_user *user, *major = ipmi_version_major(&id); *minor = ipmi_version_minor(&id); } - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1441,9 +1409,9 @@ int ipmi_set_my_address(struct ipmi_user *user, unsigned int channel, unsigned char address) { - int index, rv = 0; + int rv = 0; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1453,7 +1421,7 @@ int ipmi_set_my_address(struct ipmi_user *user, channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); user->intf->addrinfo[channel].address = address; } - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1463,9 +1431,9 @@ int ipmi_get_my_address(struct ipmi_user *user, unsigned int channel, unsigned char *address) { - int index, rv = 0; + int rv = 0; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1475,7 +1443,7 @@ int ipmi_get_my_address(struct ipmi_user *user, channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); *address = user->intf->addrinfo[channel].address; } - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1485,9 +1453,9 @@ int ipmi_set_my_LUN(struct ipmi_user *user, unsigned int channel, unsigned char LUN) { - int index, rv = 0; + int rv = 0; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1497,7 +1465,7 @@ int ipmi_set_my_LUN(struct ipmi_user *user, channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); user->intf->addrinfo[channel].lun = LUN & 0x3; } - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1507,9 +1475,9 @@ int ipmi_get_my_LUN(struct ipmi_user *user, unsigned int channel, unsigned char *address) { - int index, rv = 0; + int rv = 0; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1519,7 +1487,7 @@ int ipmi_get_my_LUN(struct ipmi_user *user, channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); *address = user->intf->addrinfo[channel].lun; } - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1527,17 +1495,17 @@ EXPORT_SYMBOL(ipmi_get_my_LUN); int ipmi_get_maintenance_mode(struct ipmi_user *user) { - int mode, index; + int mode; unsigned long flags; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags); mode = user->intf->maintenance_mode; spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags); - release_ipmi_user(user, index); + release_ipmi_user(user); return mode; } @@ -1552,11 +1520,11 @@ static void maintenance_mode_update(struct ipmi_smi *intf) int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode) { - int rv = 0, index; + int rv = 0; unsigned long flags; struct ipmi_smi *intf = user->intf; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1586,7 +1554,7 @@ int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode) } out_unlock: spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags); - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1597,9 +1565,8 @@ int ipmi_set_gets_events(struct ipmi_user *user, bool val) struct ipmi_smi *intf = user->intf; struct ipmi_recv_msg *msg, *msg2; struct list_head msgs; - int index; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1637,7 +1604,7 @@ int ipmi_set_gets_events(struct ipmi_user *user, bool val) out: mutex_unlock(&intf->events_mutex); - release_ipmi_user(user, index); + release_ipmi_user(user); return 0; } @@ -1682,9 +1649,9 @@ int ipmi_register_for_cmd(struct ipmi_user *user, { struct ipmi_smi *intf = user->intf; struct cmd_rcvr *rcvr; - int rv = 0, index; + int rv = 0; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1714,7 +1681,7 @@ int ipmi_register_for_cmd(struct ipmi_user *user, if (rv) kfree(rcvr); out_release: - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } @@ -1728,9 +1695,9 @@ int ipmi_unregister_for_cmd(struct ipmi_user *user, struct ipmi_smi *intf = user->intf; struct cmd_rcvr *rcvr; struct cmd_rcvr *rcvrs = NULL; - int i, rv = -ENOENT, index; + int i, rv = -ENOENT; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -1753,7 +1720,7 @@ int ipmi_unregister_for_cmd(struct ipmi_user *user, } mutex_unlock(&intf->cmd_rcvrs_mutex); synchronize_rcu(); - release_ipmi_user(user, index); + release_ipmi_user(user); while (rcvrs) { smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS); rcvr = rcvrs; @@ -2408,12 +2375,12 @@ int ipmi_request_settime(struct ipmi_user *user, unsigned int retry_time_ms) { unsigned char saddr = 0, lun = 0; - int rv, index; + int rv; if (!user) return -EINVAL; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -2432,7 +2399,7 @@ int ipmi_request_settime(struct ipmi_user *user, retries, retry_time_ms); - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } EXPORT_SYMBOL(ipmi_request_settime); @@ -2447,12 +2414,12 @@ int ipmi_request_supply_msgs(struct ipmi_user *user, int priority) { unsigned char saddr = 0, lun = 0; - int rv, index; + int rv; if (!user) return -EINVAL; - user = acquire_ipmi_user(user, &index); + user = acquire_ipmi_user(user); if (!user) return -ENODEV; @@ -2471,7 +2438,7 @@ int ipmi_request_supply_msgs(struct ipmi_user *user, lun, -1, 0); - release_ipmi_user(user, index); + release_ipmi_user(user); return rv; } EXPORT_SYMBOL(ipmi_request_supply_msgs); @@ -3058,7 +3025,7 @@ cleanup_bmc_device(struct kref *ref) * with removing the device attributes while reading a device * attribute. */ - queue_work(remove_work_wq, &bmc->remove_work); + queue_work(bmc_remove_work_wq, &bmc->remove_work); } /* @@ -3514,15 +3481,14 @@ static ssize_t nr_msgs_show(struct device *dev, char *buf) { struct ipmi_smi *intf = container_of(attr, - struct ipmi_smi, nr_msgs_devattr); + struct ipmi_smi, nr_msgs_devattr); struct ipmi_user *user; - int index; unsigned int count = 0; - index = srcu_read_lock(&intf->users_srcu); - list_for_each_entry_rcu(user, &intf->users, link) + mutex_lock(&intf->users_mutex); + list_for_each_entry(user, &intf->users, link) count += atomic_read(&user->nr_msgs); - srcu_read_unlock(&intf->users_srcu, index); + mutex_unlock(&intf->users_mutex); return sysfs_emit(buf, "%u\n", count); } @@ -3563,12 +3529,6 @@ int ipmi_add_smi(struct module *owner, if (!intf) return -ENOMEM; - rv = init_srcu_struct(&intf->users_srcu); - if (rv) { - kfree(intf); - return rv; - } - intf->owner = owner; intf->bmc = &intf->tmp_bmc; INIT_LIST_HEAD(&intf->bmc->intfs); @@ -3588,6 +3548,7 @@ int ipmi_add_smi(struct module *owner, INIT_LIST_HEAD(&intf->user_msgs); mutex_init(&intf->user_msgs_mutex); INIT_LIST_HEAD(&intf->users); + mutex_init(&intf->users_mutex); atomic_set(&intf->nr_users, 0); intf->handlers = handlers; intf->send_info = send_info; @@ -3688,7 +3649,6 @@ int ipmi_add_smi(struct module *owner, list_del_rcu(&intf->link); mutex_unlock(&ipmi_interfaces_mutex); synchronize_srcu(&ipmi_interfaces_srcu); - cleanup_srcu_struct(&intf->users_srcu); kref_put(&intf->refcount, intf_free); return rv; @@ -3754,7 +3714,7 @@ static void cleanup_smi_msgs(struct ipmi_smi *intf) void ipmi_unregister_smi(struct ipmi_smi *intf) { struct ipmi_smi_watcher *w; - int intf_num, index; + int intf_num; if (!intf) return; @@ -3780,15 +3740,14 @@ void ipmi_unregister_smi(struct ipmi_smi *intf) w->smi_gone(intf_num); mutex_unlock(&smi_watchers_mutex); - index = srcu_read_lock(&intf->users_srcu); + mutex_lock(&intf->users_mutex); while (!list_empty(&intf->users)) { - struct ipmi_user *user = - container_of(list_next_rcu(&intf->users), - struct ipmi_user, link); + struct ipmi_user *user = list_first_entry(&intf->users, + struct ipmi_user, link); _ipmi_destroy_user(user); } - srcu_read_unlock(&intf->users_srcu, index); + mutex_unlock(&intf->users_mutex); if (intf->handlers->shutdown) intf->handlers->shutdown(intf->send_info); @@ -3797,7 +3756,6 @@ void ipmi_unregister_smi(struct ipmi_smi *intf) ipmi_bmc_unregister(intf); - cleanup_srcu_struct(&intf->users_srcu); kref_put(&intf->refcount, intf_free); } EXPORT_SYMBOL(ipmi_unregister_smi); @@ -3942,7 +3900,7 @@ static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf, * later. */ rv = 1; - kref_put(&user->refcount, free_user); + kref_put(&user->refcount, free_ipmi_user); } else { /* Extract the source address from the data. */ ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr; @@ -4033,7 +3991,7 @@ static int handle_ipmb_direct_rcv_cmd(struct ipmi_smi *intf, * later. */ rv = 1; - kref_put(&user->refcount, free_user); + kref_put(&user->refcount, free_ipmi_user); } else { /* Extract the source address from the data. */ daddr = (struct ipmi_ipmb_direct_addr *)&recv_msg->addr; @@ -4218,7 +4176,7 @@ static int handle_lan_get_msg_cmd(struct ipmi_smi *intf, * message, so requeue it for handling later. */ rv = 1; - kref_put(&user->refcount, free_user); + kref_put(&user->refcount, free_ipmi_user); } else { /* Extract the source address from the data. */ lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr; @@ -4327,7 +4285,7 @@ static int handle_oem_get_msg_cmd(struct ipmi_smi *intf, * later. */ rv = 1; - kref_put(&user->refcount, free_user); + kref_put(&user->refcount, free_ipmi_user); } else { /* * OEM Messages are expected to be delivered via @@ -4389,7 +4347,7 @@ static int handle_read_event_rsp(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg, *recv_msg2; struct list_head msgs; struct ipmi_user *user; - int rv = 0, deliver_count = 0, index; + int rv = 0, deliver_count = 0; if (msg->rsp_size < 19) { /* Message is too small to be an IPMB event. */ @@ -4412,18 +4370,20 @@ static int handle_read_event_rsp(struct ipmi_smi *intf, * Allocate and fill in one message for every user that is * getting events. */ - index = srcu_read_lock(&intf->users_srcu); - list_for_each_entry_rcu(user, &intf->users, link) { + mutex_lock(&intf->users_mutex); + list_for_each_entry(user, &intf->users, link) { if (!user->gets_events) continue; recv_msg = ipmi_alloc_recv_msg(); if (!recv_msg) { - rcu_read_unlock(); + mutex_unlock(&intf->users_mutex); list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) { + user = recv_msg->user; list_del(&recv_msg->link); ipmi_free_recv_msg(recv_msg); + kref_put(&user->refcount, free_ipmi_user); } /* * We couldn't allocate memory for the @@ -4441,7 +4401,7 @@ static int handle_read_event_rsp(struct ipmi_smi *intf, kref_get(&user->refcount); list_add_tail(&recv_msg->link, &msgs); } - srcu_read_unlock(&intf->users_srcu, index); + mutex_unlock(&intf->users_mutex); if (deliver_count) { /* Now deliver all the messages. */ @@ -4785,23 +4745,6 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) } if (!run_to_completion) spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags); - - /* - * If the pretimout count is non-zero, decrement one from it and - * deliver pretimeouts to all the users. - */ - if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) { - struct ipmi_user *user; - int index; - - index = srcu_read_lock(&intf->users_srcu); - list_for_each_entry_rcu(user, &intf->users, link) { - if (user->handler->ipmi_watchdog_pretimeout) - user->handler->ipmi_watchdog_pretimeout( - user->handler_data); - } - srcu_read_unlock(&intf->users_srcu, index); - } } static void smi_work(struct work_struct *t) @@ -4820,8 +4763,6 @@ static void smi_work(struct work_struct *t) * message delivery. */ - rcu_read_lock(); - if (!run_to_completion) spin_lock_irqsave(&intf->xmit_msgs_lock, flags); if (intf->curr_msg == NULL && !intf->in_shutdown) { @@ -4845,17 +4786,32 @@ static void smi_work(struct work_struct *t) if (newmsg) intf->handlers->sender(intf->send_info, newmsg); - rcu_read_unlock(); - handle_new_recv_msgs(intf); + /* + * If the pretimout count is non-zero, decrement one from it and + * deliver pretimeouts to all the users. + */ + if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) { + struct ipmi_user *user; + + mutex_lock(&intf->users_mutex); + list_for_each_entry(user, &intf->users, link) { + if (user->handler->ipmi_watchdog_pretimeout) + user->handler->ipmi_watchdog_pretimeout( + user->handler_data); + } + mutex_unlock(&intf->users_mutex); + } + mutex_lock(&intf->user_msgs_mutex); list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) { struct ipmi_user *user = msg->user; + list_del(&msg->link); atomic_dec(&user->nr_msgs); user->handler->ipmi_recv_hndl(msg, user->handler_data); - kref_put(&user->refcount, free_user); + release_ipmi_user(user); } mutex_unlock(&intf->user_msgs_mutex); } @@ -5187,7 +5143,7 @@ static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void) void ipmi_free_recv_msg(struct ipmi_recv_msg *msg) { if (msg->user && !oops_in_progress) - kref_put(&msg->user->refcount, free_user); + kref_put(&msg->user->refcount, free_ipmi_user); msg->done(msg); } EXPORT_SYMBOL(ipmi_free_recv_msg); @@ -5422,7 +5378,7 @@ static int panic_event(struct notifier_block *this, has_panicked = 1; /* For every registered interface, set it to run to completion. */ - list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { + list_for_each_entry(intf, &ipmi_interfaces, link) { if (!intf->handlers || intf->intf_num == -1) /* Interface is not ready. */ continue; @@ -5452,7 +5408,7 @@ static int panic_event(struct notifier_block *this, intf->handlers->set_run_to_completion(intf->send_info, 1); - list_for_each_entry_rcu(user, &intf->users, link) { + list_for_each_entry(user, &intf->users, link) { if (user->handler->ipmi_panic_handler) user->handler->ipmi_panic_handler( user->handler_data); @@ -5501,8 +5457,8 @@ static int ipmi_init_msghandler(void) if (rv) goto out; - remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq"); - if (!remove_work_wq) { + bmc_remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq"); + if (!bmc_remove_work_wq) { pr_err("unable to create ipmi-msghandler-remove-wq workqueue"); rv = -ENOMEM; goto out_wq; @@ -5541,7 +5497,7 @@ static void __exit cleanup_ipmi(void) int count; if (initialized) { - destroy_workqueue(remove_work_wq); + destroy_workqueue(bmc_remove_work_wq); atomic_notifier_chain_unregister(&panic_notifier_list, &panic_block); -- 2.43.0