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mpt2sas: Refcount fw_events and fix unsafe list usage

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The fw_event_work struct is concurrently referenced at shutdown, so
add a refcount to protect it, and refactor the code to use it.

Additionally, refactor _scsih_fw_event_cleanup_queue() such that it
no longer iterates over the list without holding the lock, since
_firmware_event_work() concurrently deletes items from the list.

Signed-off-by: Calvin Owens <calvinowens@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Tested-by: Chaitra Basappa <chaitra.basappa@avagotech.com>
Acked-by: Sreekanth Reddy <sreekanth.reddy@avagotech.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
This commit is contained in:
Calvin Owens 2015-08-13 18:48:10 -07:00 committed by James Bottomley
parent d224fe0d60
commit 008549f6e8
1 changed files with 91 additions and 21 deletions
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112
drivers/scsi/mpt2sas/mpt2sas_scsih.c
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@ -176,9 +176,37 @@ struct fw_event_work {
u8 VP_ID;
u8 ignore;
u16 event;
struct kref refcount;
char event_data[0] __aligned(4);
};
static void fw_event_work_free(struct kref *r)
{
kfree(container_of(r, struct fw_event_work, refcount));
}
static void fw_event_work_get(struct fw_event_work *fw_work)
{
kref_get(&fw_work->refcount);
}
static void fw_event_work_put(struct fw_event_work *fw_work)
{
kref_put(&fw_work->refcount, fw_event_work_free);
}
static struct fw_event_work *alloc_fw_event_work(int len)
{
struct fw_event_work *fw_event;
fw_event = kzalloc(sizeof(*fw_event) + len, GFP_ATOMIC);
if (!fw_event)
return NULL;
kref_init(&fw_event->refcount);
return fw_event;
}
/* raid transport support */
static struct raid_template *mpt2sas_raid_template;
@ -2872,36 +2900,39 @@ _scsih_fw_event_add(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work *fw_event)
return;
spin_lock_irqsave(&ioc->fw_event_lock, flags);
fw_event_work_get(fw_event);
list_add_tail(&fw_event->list, &ioc->fw_event_list);
INIT_DELAYED_WORK(&fw_event->delayed_work, _firmware_event_work);
fw_event_work_get(fw_event);
queue_delayed_work(ioc->firmware_event_thread,
&fw_event->delayed_work, 0);
spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
}
/**
* _scsih_fw_event_free - delete fw_event
* _scsih_fw_event_del_from_list - delete fw_event from the list
* @ioc: per adapter object
* @fw_event: object describing the event
* Context: This function will acquire ioc->fw_event_lock.
*
* This removes firmware event object from link list, frees associated memory.
* If the fw_event is on the fw_event_list, remove it and do a put.
*
* Return nothing.
*/
static void
_scsih_fw_event_free(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work
_scsih_fw_event_del_from_list(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work
*fw_event)
{
unsigned long flags;
spin_lock_irqsave(&ioc->fw_event_lock, flags);
list_del(&fw_event->list);
kfree(fw_event);
if (!list_empty(&fw_event->list)) {
list_del_init(&fw_event->list);
fw_event_work_put(fw_event);
}
spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
}
/**
* _scsih_error_recovery_delete_devices - remove devices not responding
* @ioc: per adapter object
@ -2916,13 +2947,14 @@ _scsih_error_recovery_delete_devices(struct MPT2SAS_ADAPTER *ioc)
if (ioc->is_driver_loading)
return;
fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
fw_event = alloc_fw_event_work(0);
if (!fw_event)
return;
fw_event->event = MPT2SAS_REMOVE_UNRESPONDING_DEVICES;
fw_event->ioc = ioc;
_scsih_fw_event_add(ioc, fw_event);
fw_event_work_put(fw_event);
}
/**
@ -2936,12 +2968,29 @@ mpt2sas_port_enable_complete(struct MPT2SAS_ADAPTER *ioc)
{
struct fw_event_work *fw_event;
fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
fw_event = alloc_fw_event_work(0);
if (!fw_event)
return;
fw_event->event = MPT2SAS_PORT_ENABLE_COMPLETE;
fw_event->ioc = ioc;
_scsih_fw_event_add(ioc, fw_event);
fw_event_work_put(fw_event);
}
static struct fw_event_work *dequeue_next_fw_event(struct MPT2SAS_ADAPTER *ioc)
{
unsigned long flags;
struct fw_event_work *fw_event = NULL;
spin_lock_irqsave(&ioc->fw_event_lock, flags);
if (!list_empty(&ioc->fw_event_list)) {
fw_event = list_first_entry(&ioc->fw_event_list,
struct fw_event_work, list);
list_del_init(&fw_event->list);
}
spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
return fw_event;
}
/**
@ -2956,17 +3005,25 @@ mpt2sas_port_enable_complete(struct MPT2SAS_ADAPTER *ioc)
static void
_scsih_fw_event_cleanup_queue(struct MPT2SAS_ADAPTER *ioc)
{
struct fw_event_work *fw_event, *next;
struct fw_event_work *fw_event;
if (list_empty(&ioc->fw_event_list) ||
!ioc->firmware_event_thread || in_interrupt())
return;
list_for_each_entry_safe(fw_event, next, &ioc->fw_event_list, list) {
if (cancel_delayed_work_sync(&fw_event->delayed_work)) {
_scsih_fw_event_free(ioc, fw_event);
continue;
}
while ((fw_event = dequeue_next_fw_event(ioc))) {
/*
* Wait on the fw_event to complete. If this returns 1, then
* the event was never executed, and we need a put for the
* reference the delayed_work had on the fw_event.
*
* If it did execute, we wait for it to finish, and the put will
* happen from _firmware_event_work()
*/
if (cancel_delayed_work_sync(&fw_event->delayed_work))
fw_event_work_put(fw_event);
fw_event_work_put(fw_event);
}
}
@ -4447,13 +4504,14 @@ _scsih_send_event_to_turn_on_pfa_led(struct MPT2SAS_ADAPTER *ioc, u16 handle)
{
struct fw_event_work *fw_event;
fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
fw_event = alloc_fw_event_work(0);
if (!fw_event)
return;
fw_event->event = MPT2SAS_TURN_ON_PFA_LED;
fw_event->device_handle = handle;
fw_event->ioc = ioc;
_scsih_fw_event_add(ioc, fw_event);
fw_event_work_put(fw_event);
}
/**
@ -7554,17 +7612,27 @@ _firmware_event_work(struct work_struct *work)
struct fw_event_work, delayed_work.work);
struct MPT2SAS_ADAPTER *ioc = fw_event->ioc;
_scsih_fw_event_del_from_list(ioc, fw_event);
/* the queue is being flushed so ignore this event */
if (ioc->remove_host ||
ioc->pci_error_recovery) {
_scsih_fw_event_free(ioc, fw_event);
if (ioc->remove_host || ioc->pci_error_recovery) {
fw_event_work_put(fw_event);
return;
}
switch (fw_event->event) {
case MPT2SAS_REMOVE_UNRESPONDING_DEVICES:
while (scsi_host_in_recovery(ioc->shost) || ioc->shost_recovery)
while (scsi_host_in_recovery(ioc->shost) ||
ioc->shost_recovery) {
/*
* If we're unloading, bail. Otherwise, this can become
* an infinite loop.
*/
if (ioc->remove_host)
goto out;
ssleep(1);
}
_scsih_remove_unresponding_sas_devices(ioc);
_scsih_scan_for_devices_after_reset(ioc);
break;
@ -7613,7 +7681,8 @@ _firmware_event_work(struct work_struct *work)
_scsih_sas_ir_operation_status_event(ioc, fw_event);
break;
}
_scsih_fw_event_free(ioc, fw_event);
out:
fw_event_work_put(fw_event);
}
/**
@ -7751,7 +7820,7 @@ mpt2sas_scsih_event_callback(struct MPT2SAS_ADAPTER *ioc, u8 msix_index,
}
sz = le16_to_cpu(mpi_reply->EventDataLength) * 4;
fw_event = kzalloc(sizeof(*fw_event) + sz, GFP_ATOMIC);
fw_event = alloc_fw_event_work(sz);
if (!fw_event) {
printk(MPT2SAS_ERR_FMT "failure at %s:%d/%s()!\n",
ioc->name, __FILE__, __LINE__, __func__);
@ -7764,6 +7833,7 @@ mpt2sas_scsih_event_callback(struct MPT2SAS_ADAPTER *ioc, u8 msix_index,
fw_event->VP_ID = mpi_reply->VP_ID;
fw_event->event = event;
_scsih_fw_event_add(ioc, fw_event);
fw_event_work_put(fw_event);
return;
}