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scsi: hpsa: correct device resets

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Correct a race condition that occurs between the reset handler and the
completion handler. There are times when the wait_event condition is
never met due to this race condition and the reset never completes.

The reset_pending field is NULL initially.

  t  Reset Handler Thread     Completion Thread
  -- --------------------     -----------------
  t1                          if (c->reset_pending)
  t2 c->reset_pending = dev;     if (atomic_dev_and_test(counter))
  t3 atomic_inc(counter)             wait_up_all(event_sync_wait_queue)
  t4
  t5 wait_event(...counter == 0)

Kernel.org Bugzilla:
           https://bugzilla.kernel.org/show_bug.cgi?id=1994350
           Bug 199435 - HPSA + P420i resetting logical Direct-Access
                        never complete

Reviewed-by: Justin Lindley <justin.lindley@microsemi.com>
Reviewed-by: David Carroll <david.carroll@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Don Brace 2019-05-07 13:32:33 -05:00 committed by Martin K. Petersen
parent 9e33f0d578
commit c5dfd10641
3 changed files with 88 additions and 90 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

173
drivers/scsi/hpsa.c
View File

@ -346,11 +346,6 @@ static inline bool hpsa_is_cmd_idle(struct CommandList *c)
return c->scsi_cmd == SCSI_CMD_IDLE;
}
static inline bool hpsa_is_pending_event(struct CommandList *c)
{
return c->reset_pending;
}
/* extract sense key, asc, and ascq from sense data. -1 means invalid. */
static void decode_sense_data(const u8 *sense_data, int sense_data_len,
u8 *sense_key, u8 *asc, u8 *ascq)
@ -1146,6 +1141,8 @@ static void __enqueue_cmd_and_start_io(struct ctlr_info *h,
{
dial_down_lockup_detection_during_fw_flash(h, c);
atomic_inc(&h->commands_outstanding);
if (c->device)
atomic_inc(&c->device->commands_outstanding);
reply_queue = h->reply_map[raw_smp_processor_id()];
switch (c->cmd_type) {
@ -1169,9 +1166,6 @@ static void __enqueue_cmd_and_start_io(struct ctlr_info *h,
static void enqueue_cmd_and_start_io(struct ctlr_info *h, struct CommandList *c)
{
if (unlikely(hpsa_is_pending_event(c)))
return finish_cmd(c);
__enqueue_cmd_and_start_io(h, c, DEFAULT_REPLY_QUEUE);
}
@ -2434,13 +2428,16 @@ static int handle_ioaccel_mode2_error(struct ctlr_info *h,
break;
}
if (dev->in_reset)
retry = 0;
return retry; /* retry on raid path? */
}
static void hpsa_cmd_resolve_events(struct ctlr_info *h,
struct CommandList *c)
{
bool do_wake = false;
struct hpsa_scsi_dev_t *dev = c->device;
/*
* Reset c->scsi_cmd here so that the reset handler will know
@ -2449,25 +2446,12 @@ static void hpsa_cmd_resolve_events(struct ctlr_info *h,
*/
c->scsi_cmd = SCSI_CMD_IDLE;
mb(); /* Declare command idle before checking for pending events. */
if (c->reset_pending) {
unsigned long flags;
struct hpsa_scsi_dev_t *dev;
/*
* There appears to be a reset pending; lock the lock and
* reconfirm. If so, then decrement the count of outstanding
* commands and wake the reset command if this is the last one.
*/
spin_lock_irqsave(&h->lock, flags);
dev = c->reset_pending; /* Re-fetch under the lock. */
if (dev && atomic_dec_and_test(&dev->reset_cmds_out))
do_wake = true;
c->reset_pending = NULL;
spin_unlock_irqrestore(&h->lock, flags);
if (dev) {
atomic_dec(&dev->commands_outstanding);
if (dev->in_reset &&
atomic_read(&dev->commands_outstanding) <= 0)
wake_up_all(&h->event_sync_wait_queue);
}
if (do_wake)
wake_up_all(&h->event_sync_wait_queue);
}
static void hpsa_cmd_resolve_and_free(struct ctlr_info *h,
@ -2516,6 +2500,11 @@ static void process_ioaccel2_completion(struct ctlr_info *h,
dev->offload_to_be_enabled = 0;
}
if (dev->in_reset) {
cmd->result = DID_RESET << 16;
return hpsa_cmd_free_and_done(h, c, cmd);
}
return hpsa_retry_cmd(h, c);
}
@ -2621,10 +2610,6 @@ static void complete_scsi_command(struct CommandList *cp)
return hpsa_cmd_free_and_done(h, cp, cmd);
}
if ((unlikely(hpsa_is_pending_event(cp))))
if (cp->reset_pending)
return hpsa_cmd_free_and_done(h, cp, cmd);
if (cp->cmd_type == CMD_IOACCEL2)
return process_ioaccel2_completion(h, cp, cmd, dev);
@ -3074,7 +3059,7 @@ out:
return rc;
}
static int hpsa_send_reset(struct ctlr_info *h, unsigned char *scsi3addr,
static int hpsa_send_reset(struct ctlr_info *h, struct hpsa_scsi_dev_t *dev,
u8 reset_type, int reply_queue)
{
int rc = IO_OK;
@ -3082,11 +3067,10 @@ static int hpsa_send_reset(struct ctlr_info *h, unsigned char *scsi3addr,
struct ErrorInfo *ei;
c = cmd_alloc(h);
c->device = dev;
/* fill_cmd can't fail here, no data buffer to map. */
(void) fill_cmd(c, reset_type, h, NULL, 0, 0,
scsi3addr, TYPE_MSG);
(void) fill_cmd(c, reset_type, h, NULL, 0, 0, dev->scsi3addr, TYPE_MSG);
rc = hpsa_scsi_do_simple_cmd(h, c, reply_queue, NO_TIMEOUT);
if (rc) {
dev_warn(&h->pdev->dev, "Failed to send reset command\n");
@ -3164,9 +3148,8 @@ static bool hpsa_cmd_dev_match(struct ctlr_info *h, struct CommandList *c,
}
static int hpsa_do_reset(struct ctlr_info *h, struct hpsa_scsi_dev_t *dev,
unsigned char *scsi3addr, u8 reset_type, int reply_queue)
u8 reset_type, int reply_queue)
{
int i;
int rc = 0;
/* We can really only handle one reset at a time */
@ -3175,38 +3158,14 @@ static int hpsa_do_reset(struct ctlr_info *h, struct hpsa_scsi_dev_t *dev,
return -EINTR;
}
BUG_ON(atomic_read(&dev->reset_cmds_out) != 0);
for (i = 0; i < h->nr_cmds; i++) {
struct CommandList *c = h->cmd_pool + i;
int refcount = atomic_inc_return(&c->refcount);
if (refcount > 1 && hpsa_cmd_dev_match(h, c, dev, scsi3addr)) {
unsigned long flags;
/*
* Mark the target command as having a reset pending,
* then lock a lock so that the command cannot complete
* while we're considering it. If the command is not
* idle then count it; otherwise revoke the event.
*/
c->reset_pending = dev;
spin_lock_irqsave(&h->lock, flags); /* Implied MB */
if (!hpsa_is_cmd_idle(c))
atomic_inc(&dev->reset_cmds_out);
else
c->reset_pending = NULL;
spin_unlock_irqrestore(&h->lock, flags);
}
cmd_free(h, c);
}
rc = hpsa_send_reset(h, scsi3addr, reset_type, reply_queue);
if (!rc)
rc = hpsa_send_reset(h, dev, reset_type, reply_queue);
if (!rc) {
/* incremented by sending the reset request */
atomic_dec(&dev->commands_outstanding);
wait_event(h->event_sync_wait_queue,
atomic_read(&dev->reset_cmds_out) == 0 ||
atomic_read(&dev->commands_outstanding) <= 0 ||
lockup_detected(h));
}
if (unlikely(lockup_detected(h))) {
dev_warn(&h->pdev->dev,
@ -3214,10 +3173,8 @@ static int hpsa_do_reset(struct ctlr_info *h, struct hpsa_scsi_dev_t *dev,
rc = -ENODEV;
}
if (unlikely(rc))
atomic_set(&dev->reset_cmds_out, 0);
else
rc = wait_for_device_to_become_ready(h, scsi3addr, 0);
if (!rc)
rc = wait_for_device_to_become_ready(h, dev->scsi3addr, 0);
mutex_unlock(&h->reset_mutex);
return rc;
@ -4846,6 +4803,9 @@ static int hpsa_scsi_ioaccel_direct_map(struct ctlr_info *h,
c->phys_disk = dev;
if (dev->in_reset)
return -1;
return hpsa_scsi_ioaccel_queue_command(h, c, dev->ioaccel_handle,
cmd->cmnd, cmd->cmd_len, dev->scsi3addr, dev);
}
@ -5031,6 +4991,11 @@ static int hpsa_scsi_ioaccel2_queue_command(struct ctlr_info *h,
} else
cp->sg_count = (u8) use_sg;
if (phys_disk->in_reset) {
cmd->result = DID_RESET << 16;
return -1;
}
enqueue_cmd_and_start_io(h, c);
return 0;
}
@ -5048,6 +5013,9 @@ static int hpsa_scsi_ioaccel_queue_command(struct ctlr_info *h,
if (!c->scsi_cmd->device->hostdata)
return -1;
if (phys_disk->in_reset)
return -1;
/* Try to honor the device's queue depth */
if (atomic_inc_return(&phys_disk->ioaccel_cmds_out) >
phys_disk->queue_depth) {
@ -5131,6 +5099,9 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
if (!dev)
return -1;
if (dev->in_reset)
return -1;
/* check for valid opcode, get LBA and block count */
switch (cmd->cmnd[0]) {
case WRITE_6:
@ -5435,13 +5406,13 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
*/
static int hpsa_ciss_submit(struct ctlr_info *h,
struct CommandList *c, struct scsi_cmnd *cmd,
unsigned char scsi3addr[])
struct hpsa_scsi_dev_t *dev)
{
cmd->host_scribble = (unsigned char *) c;
c->cmd_type = CMD_SCSI;
c->scsi_cmd = cmd;
c->Header.ReplyQueue = 0; /* unused in simple mode */
memcpy(&c->Header.LUN.LunAddrBytes[0], &scsi3addr[0], 8);
memcpy(&c->Header.LUN.LunAddrBytes[0], &dev->scsi3addr[0], 8);
c->Header.tag = cpu_to_le64((c->cmdindex << DIRECT_LOOKUP_SHIFT));
/* Fill in the request block... */
@ -5492,6 +5463,12 @@ static int hpsa_ciss_submit(struct ctlr_info *h,
hpsa_cmd_resolve_and_free(h, c);
return SCSI_MLQUEUE_HOST_BUSY;
}
if (dev->in_reset) {
hpsa_cmd_resolve_and_free(h, c);
return SCSI_MLQUEUE_HOST_BUSY;
}
enqueue_cmd_and_start_io(h, c);
/* the cmd'll come back via intr handler in complete_scsi_command() */
return 0;
@ -5543,8 +5520,7 @@ static inline void hpsa_cmd_partial_init(struct ctlr_info *h, int index,
}
static int hpsa_ioaccel_submit(struct ctlr_info *h,
struct CommandList *c, struct scsi_cmnd *cmd,
unsigned char *scsi3addr)
struct CommandList *c, struct scsi_cmnd *cmd)
{
struct hpsa_scsi_dev_t *dev = cmd->device->hostdata;
int rc = IO_ACCEL_INELIGIBLE;
@ -5552,6 +5528,9 @@ static int hpsa_ioaccel_submit(struct ctlr_info *h,
if (!dev)
return SCSI_MLQUEUE_HOST_BUSY;
if (dev->in_reset)
return SCSI_MLQUEUE_HOST_BUSY;
if (hpsa_simple_mode)
return IO_ACCEL_INELIGIBLE;
@ -5587,8 +5566,12 @@ static void hpsa_command_resubmit_worker(struct work_struct *work)
cmd->result = DID_NO_CONNECT << 16;
return hpsa_cmd_free_and_done(c->h, c, cmd);
}
if (c->reset_pending)
if (dev->in_reset) {
cmd->result = DID_RESET << 16;
return hpsa_cmd_free_and_done(c->h, c, cmd);
}
if (c->cmd_type == CMD_IOACCEL2) {
struct ctlr_info *h = c->h;
struct io_accel2_cmd *c2 = &h->ioaccel2_cmd_pool[c->cmdindex];
@ -5596,7 +5579,7 @@ static void hpsa_command_resubmit_worker(struct work_struct *work)
if (c2->error_data.serv_response ==
IOACCEL2_STATUS_SR_TASK_COMP_SET_FULL) {
rc = hpsa_ioaccel_submit(h, c, cmd, dev->scsi3addr);
rc = hpsa_ioaccel_submit(h, c, cmd);
if (rc == 0)
return;
if (rc == SCSI_MLQUEUE_HOST_BUSY) {
@ -5612,7 +5595,7 @@ static void hpsa_command_resubmit_worker(struct work_struct *work)
}
}
hpsa_cmd_partial_init(c->h, c->cmdindex, c);
if (hpsa_ciss_submit(c->h, c, cmd, dev->scsi3addr)) {
if (hpsa_ciss_submit(c->h, c, cmd, dev)) {
/*
* If we get here, it means dma mapping failed. Try
* again via scsi mid layer, which will then get
@ -5631,7 +5614,6 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
{
struct ctlr_info *h;
struct hpsa_scsi_dev_t *dev;
unsigned char scsi3addr[8];
struct CommandList *c;
int rc = 0;
@ -5653,13 +5635,15 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
return 0;
}
memcpy(scsi3addr, dev->scsi3addr, sizeof(scsi3addr));
if (unlikely(lockup_detected(h))) {
cmd->result = DID_NO_CONNECT << 16;
cmd->scsi_done(cmd);
return 0;
}
if (dev->in_reset)
return SCSI_MLQUEUE_DEVICE_BUSY;
c = cmd_tagged_alloc(h, cmd);
if (c == NULL)
return SCSI_MLQUEUE_DEVICE_BUSY;
@ -5671,7 +5655,7 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
if (likely(cmd->retries == 0 &&
!blk_rq_is_passthrough(cmd->request) &&
h->acciopath_status)) {
rc = hpsa_ioaccel_submit(h, c, cmd, scsi3addr);
rc = hpsa_ioaccel_submit(h, c, cmd);
if (rc == 0)
return 0;
if (rc == SCSI_MLQUEUE_HOST_BUSY) {
@ -5679,7 +5663,7 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
return SCSI_MLQUEUE_HOST_BUSY;
}
}
return hpsa_ciss_submit(h, c, cmd, scsi3addr);
return hpsa_ciss_submit(h, c, cmd, dev);
}
static void hpsa_scan_complete(struct ctlr_info *h)
@ -5961,6 +5945,7 @@ static int wait_for_device_to_become_ready(struct ctlr_info *h,
static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
{
int rc = SUCCESS;
int i;
struct ctlr_info *h;
struct hpsa_scsi_dev_t *dev;
u8 reset_type;
@ -6028,9 +6013,19 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
reset_type == HPSA_DEVICE_RESET_MSG ? "logical " : "physical ");
hpsa_show_dev_msg(KERN_WARNING, h, dev, msg);
/*
* wait to see if any commands will complete before sending reset
*/
dev->in_reset = true; /* block any new cmds from OS for this device */
for (i = 0; i < 10; i++) {
if (atomic_read(&dev->commands_outstanding) > 0)
msleep(1000);
else
break;
}
/* send a reset to the SCSI LUN which the command was sent to */
rc = hpsa_do_reset(h, dev, dev->scsi3addr, reset_type,
DEFAULT_REPLY_QUEUE);
rc = hpsa_do_reset(h, dev, reset_type, DEFAULT_REPLY_QUEUE);
if (rc == 0)
rc = SUCCESS;
else
@ -6044,6 +6039,8 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
return_reset_status:
spin_lock_irqsave(&h->reset_lock, flags);
h->reset_in_progress = 0;
if (dev)
dev->in_reset = false;
spin_unlock_irqrestore(&h->reset_lock, flags);
return rc;
}
@ -6157,6 +6154,7 @@ static struct CommandList *cmd_alloc(struct ctlr_info *h)
break; /* it's ours now. */
}
hpsa_cmd_partial_init(h, i, c);
c->device = NULL;
return c;
}
@ -6610,8 +6608,7 @@ static int hpsa_ioctl(struct scsi_device *dev, unsigned int cmd,
}
}
static void hpsa_send_host_reset(struct ctlr_info *h, unsigned char *scsi3addr,
u8 reset_type)
static void hpsa_send_host_reset(struct ctlr_info *h, u8 reset_type)
{
struct CommandList *c;
@ -8105,7 +8102,7 @@ static int hpsa_request_irqs(struct ctlr_info *h,
static int hpsa_kdump_soft_reset(struct ctlr_info *h)
{
int rc;
hpsa_send_host_reset(h, RAID_CTLR_LUNID, HPSA_RESET_TYPE_CONTROLLER);
hpsa_send_host_reset(h, HPSA_RESET_TYPE_CONTROLLER);
dev_info(&h->pdev->dev, "Waiting for board to soft reset.\n");
rc = hpsa_wait_for_board_state(h->pdev, h->vaddr, BOARD_NOT_READY);

3
drivers/scsi/hpsa.h
View File

@ -76,11 +76,12 @@ struct hpsa_scsi_dev_t {
unsigned char raid_level; /* from inquiry page 0xC1 */
unsigned char volume_offline; /* discovered via TUR or VPD */
u16 queue_depth; /* max queue_depth for this device */
atomic_t reset_cmds_out; /* Count of commands to-be affected */
atomic_t commands_outstanding; /* track commands sent to device */
atomic_t ioaccel_cmds_out; /* Only used for physical devices
* counts commands sent to physical
* device via "ioaccel" path.
*/
bool in_reset;
u32 ioaccel_handle;
u8 active_path_index;
u8 path_map;

2
drivers/scsi/hpsa_cmd.h
View File

@ -448,7 +448,7 @@ struct CommandList {
struct hpsa_scsi_dev_t *phys_disk;
int abort_pending;
struct hpsa_scsi_dev_t *reset_pending;
struct hpsa_scsi_dev_t *device;
atomic_t refcount; /* Must be last to avoid memset in hpsa_cmd_init() */
} __aligned(COMMANDLIST_ALIGNMENT);