Date: Fri, 7 Mar 2014 10:19:57 -0500 From: Tejun Heo Subject: firewire: don't use PREPARE_DELAYED_WORK PREPARE_[DELAYED_]WORK() are being phased out. They have few users and a nasty surprise in terms of reentrancy guarantee as workqueue considers work items to be different if they don't have the same work function. firewire core-device and sbp2 have been been multiplexing work items with multiple work functions. Introduce fw_device_workfn() and sbp2_lu_workfn() which invoke fw_device->workfn and sbp2_logical_unit->workfn respectively and always use the two functions as the work functions and update the users to set the ->workfn fields instead of overriding work functions using PREPARE_DELAYED_WORK(). This fixes a variety of possible regressions since a2c1c57be8d9 "workqueue: consider work function when searching for busy work items" due to which fw_workqueue lost its required non-reentrancy property. Signed-off-by: Tejun Heo Acked-by: Stefan Richter Cc: linux1394-devel@lists.sourceforge.net Cc: stable@vger.kernel.org # v3.9+ Cc: stable@vger.kernel.org # v3.8.2+ Cc: stable@vger.kernel.org # v3.4.60+ Cc: stable@vger.kernel.org # v3.2.40+ --- drivers/firewire/core-device.c | 22 +++++++++++++++------- drivers/firewire/sbp2.c | 17 +++++++++++++---- include/linux/firewire.h | 1 + 3 files changed, 29 insertions(+), 11 deletions(-) --- a/drivers/firewire/core-device.c +++ b/drivers/firewire/core-device.c @@ -916,7 +916,7 @@ static int lookup_existing_device(struct old->config_rom_retries = 0; fw_notice(card, "rediscovered device %s\n", dev_name(dev)); - PREPARE_DELAYED_WORK(&old->work, fw_device_update); + old->workfn = fw_device_update; fw_schedule_device_work(old, 0); if (current_node == card->root_node) @@ -1075,7 +1075,7 @@ static void fw_device_init(struct work_s if (atomic_cmpxchg(&device->state, FW_DEVICE_INITIALIZING, FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { - PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown); + device->workfn = fw_device_shutdown; fw_schedule_device_work(device, SHUTDOWN_DELAY); } else { fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n", @@ -1196,13 +1196,20 @@ static void fw_device_refresh(struct wor dev_name(&device->device), fw_rcode_string(ret)); gone: atomic_set(&device->state, FW_DEVICE_GONE); - PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown); + device->workfn = fw_device_shutdown; fw_schedule_device_work(device, SHUTDOWN_DELAY); out: if (node_id == card->root_node->node_id) fw_schedule_bm_work(card, 0); } +static void fw_device_workfn(struct work_struct *work) +{ + struct fw_device *device = container_of(to_delayed_work(work), + struct fw_device, work); + device->workfn(work); +} + void fw_node_event(struct fw_card *card, struct fw_node *node, int event) { struct fw_device *device; @@ -1252,7 +1259,8 @@ void fw_node_event(struct fw_card *card, * power-up after getting plugged in. We schedule the * first config rom scan half a second after bus reset. */ - INIT_DELAYED_WORK(&device->work, fw_device_init); + device->workfn = fw_device_init; + INIT_DELAYED_WORK(&device->work, fw_device_workfn); fw_schedule_device_work(device, INITIAL_DELAY); break; @@ -1268,7 +1276,7 @@ void fw_node_event(struct fw_card *card, if (atomic_cmpxchg(&device->state, FW_DEVICE_RUNNING, FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) { - PREPARE_DELAYED_WORK(&device->work, fw_device_refresh); + device->workfn = fw_device_refresh; fw_schedule_device_work(device, device->is_local ? 0 : INITIAL_DELAY); } @@ -1283,7 +1291,7 @@ void fw_node_event(struct fw_card *card, smp_wmb(); /* update node_id before generation */ device->generation = card->generation; if (atomic_read(&device->state) == FW_DEVICE_RUNNING) { - PREPARE_DELAYED_WORK(&device->work, fw_device_update); + device->workfn = fw_device_update; fw_schedule_device_work(device, 0); } break; @@ -1308,7 +1316,7 @@ void fw_node_event(struct fw_card *card, device = node->data; if (atomic_xchg(&device->state, FW_DEVICE_GONE) == FW_DEVICE_RUNNING) { - PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown); + device->workfn = fw_device_shutdown; fw_schedule_device_work(device, list_empty(&card->link) ? 0 : SHUTDOWN_DELAY); } --- a/drivers/firewire/sbp2.c +++ b/drivers/firewire/sbp2.c @@ -146,6 +146,7 @@ struct sbp2_logical_unit { */ int generation; int retries; + work_func_t workfn; struct delayed_work work; bool has_sdev; bool blocked; @@ -864,7 +865,7 @@ static void sbp2_login(struct work_struc /* set appropriate retry limit(s) in BUSY_TIMEOUT register */ sbp2_set_busy_timeout(lu); - PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect); + lu->workfn = sbp2_reconnect; sbp2_agent_reset(lu); /* This was a re-login. */ @@ -918,7 +919,7 @@ static void sbp2_login(struct work_struc * If a bus reset happened, sbp2_update will have requeued * lu->work already. Reset the work from reconnect to login. */ - PREPARE_DELAYED_WORK(&lu->work, sbp2_login); + lu->workfn = sbp2_login; } static void sbp2_reconnect(struct work_struct *work) @@ -952,7 +953,7 @@ static void sbp2_reconnect(struct work_s lu->retries++ >= 5) { dev_err(tgt_dev(tgt), "failed to reconnect\n"); lu->retries = 0; - PREPARE_DELAYED_WORK(&lu->work, sbp2_login); + lu->workfn = sbp2_login; } sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5)); @@ -972,6 +973,13 @@ static void sbp2_reconnect(struct work_s sbp2_conditionally_unblock(lu); } +static void sbp2_lu_workfn(struct work_struct *work) +{ + struct sbp2_logical_unit *lu = container_of(to_delayed_work(work), + struct sbp2_logical_unit, work); + lu->workfn(work); +} + static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry) { struct sbp2_logical_unit *lu; @@ -998,7 +1006,8 @@ static int sbp2_add_logical_unit(struct lu->blocked = false; ++tgt->dont_block; INIT_LIST_HEAD(&lu->orb_list); - INIT_DELAYED_WORK(&lu->work, sbp2_login); + lu->workfn = sbp2_login; + INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn); list_add_tail(&lu->link, &tgt->lu_list); return 0; --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -200,6 +200,7 @@ struct fw_device { unsigned irmc:1; unsigned bc_implemented:2; + work_func_t workfn; struct delayed_work work; struct fw_attribute_group attribute_group; };