[PATCH 47/47] scsi: Do not allocate scsi command in scsi_ioctl_reset()

Hannes Reinecke
2017-06-28T08:33:40Z

As we now have moved the error handler functions to not rely on
a scsi command we can drop the out-of-band scsi command allocation
from scsi_ioctl_reset().

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/scsi_error.c | 124 +++++++++++++++++++---------------------------
1 file changed, 50 insertions(+), 74 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 4a7fe97f..ab178e8 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -728,16 +728,22 @@ static void scsi_eh_done(struct scsi_cmnd *scmd)
complete(eh_action);
}

+static void __scsi_report_device_reset(struct scsi_device *sdev)
+{
+ sdev->was_reset = 1;
+ sdev->expecting_cc_ua = 1;
+}
+
/**
* scsi_try_host_reset - ask host adapter to reset itself
- * @scmd: SCSI cmd to send host reset.
+ * @host: SCSI host to be reset.
*/
-static int scsi_try_host_reset(struct scsi_cmnd *scmd)
+static int scsi_try_host_reset(struct Scsi_Host *host)
{
unsigned long flags;
int rtn;
- struct Scsi_Host *host = scmd->device->host;
struct scsi_host_template *hostt = host->hostt;
+ struct scsi_device *sdev;

SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, host, "Snd Host RST\n"));
@@ -751,7 +757,8 @@ static int scsi_try_host_reset(struct scsi_cmnd *scmd)
if (!hostt->skip_settle_delay)
ssleep(HOST_RESET_SETTLE_TIME);
spin_lock_irqsave(host->host_lock, flags);
- scsi_report_bus_reset(host, scmd_channel(scmd));
+ __shost_for_each_device(sdev, host)
+ __scsi_report_device_reset(sdev);
spin_unlock_irqrestore(host->host_lock, flags);
}

@@ -760,43 +767,38 @@ static int scsi_try_host_reset(struct scsi_cmnd *scmd)

/**
* scsi_try_bus_reset - ask host to perform a bus reset
- * @scmd: SCSI cmd to send bus reset.
+ * @host: SCSI host to send bus reset.
+ * @channel: bus number to be reset.
*/
-static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
+static int scsi_try_bus_reset(struct Scsi_Host *host, int channel)
{
unsigned long flags;
int rtn;
- struct Scsi_Host *host = scmd->device->host;
struct scsi_host_template *hostt = host->hostt;

- SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
+ SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, host,
"%s: Snd Bus RST\n", __func__));

if (!hostt->eh_bus_reset_handler)
return FAILED;

- rtn = hostt->eh_bus_reset_handler(host, scmd_channel(scmd));
+ rtn = hostt->eh_bus_reset_handler(host, channel);

if (rtn == SUCCESS) {
if (!hostt->skip_settle_delay)
ssleep(BUS_RESET_SETTLE_TIME);
spin_lock_irqsave(host->host_lock, flags);
- scsi_report_bus_reset(host, scmd_channel(scmd));
+ scsi_report_bus_reset(host, channel);
spin_unlock_irqrestore(host->host_lock, flags);
}

return rtn;
}

-static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
-{
- sdev->was_reset = 1;
- sdev->expecting_cc_ua = 1;
-}
-
/**
* scsi_try_target_reset - Ask host to perform a target reset
- * @scmd: SCSI cmd used to send a target reset
+ * @shost: SCSI Host
+ * @starget: SCSI target to be reset
*
* Notes:
* There is no timeout for this operation. if this operation is
@@ -804,13 +806,13 @@ static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
* timer on it, and set the host back to a consistent state prior to
* returning.
*/
-static int scsi_try_target_reset(struct scsi_cmnd *scmd)
+static int scsi_try_target_reset(struct Scsi_Host *host,
+ struct scsi_target *starget)
{
unsigned long flags;
int rtn;
- struct Scsi_Host *host = scmd->device->host;
+ struct scsi_device *sdev;
struct scsi_host_template *hostt = host->hostt;
- struct scsi_target *starget = scsi_target(scmd->device);

if (!hostt->eh_target_reset_handler)
return FAILED;
@@ -818,8 +820,11 @@ static int scsi_try_target_reset(struct scsi_cmnd *scmd)
rtn = hostt->eh_target_reset_handler(starget);
if (rtn == SUCCESS) {
spin_lock_irqsave(host->host_lock, flags);
- __starget_for_each_device(starget, NULL,
- __scsi_report_device_reset);
+ __shost_for_each_device(sdev, host) {
+ if ((sdev->channel == starget->channel) &&
+ (sdev->id == starget->id))
+ __scsi_report_device_reset(sdev);
+ }
spin_unlock_irqrestore(host->host_lock, flags);
}

@@ -836,17 +841,17 @@ static int scsi_try_target_reset(struct scsi_cmnd *scmd)
* timer on it, and set the host back to a consistent state prior to
* returning.
*/
-static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
+static int scsi_try_bus_device_reset(struct scsi_device *sdev)
{
int rtn;
- struct scsi_host_template *hostt = scmd->device->host->hostt;
+ struct scsi_host_template *hostt = sdev->host->hostt;

if (!hostt->eh_device_reset_handler)
return FAILED;

- rtn = hostt->eh_device_reset_handler(scmd->device);
+ rtn = hostt->eh_device_reset_handler(sdev);
if (rtn == SUCCESS)
- __scsi_report_device_reset(scmd->device, NULL);
+ __scsi_report_device_reset(sdev);
return rtn;
}

@@ -878,11 +883,15 @@ static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt,

static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
{
- if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
- if (scsi_try_bus_device_reset(scmd) != SUCCESS)
- if (scsi_try_target_reset(scmd) != SUCCESS)
- if (scsi_try_bus_reset(scmd) != SUCCESS)
- scsi_try_host_reset(scmd);
+ struct Scsi_Host *host = scmd->device->host;
+ struct scsi_target *starget = scsi_target(scmd->device);
+ int channel = scmd->device->channel;
+
+ if (scsi_try_to_abort_cmd(host->hostt, scmd) != SUCCESS)
+ if (scsi_try_bus_device_reset(scmd->device) != SUCCESS)
+ if (scsi_try_target_reset(host, starget) != SUCCESS)
+ if (scsi_try_bus_reset(host, channel) != SUCCESS)
+ scsi_try_host_reset(host);
}

/**
@@ -1430,7 +1439,7 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
SCSI_LOG_ERROR_RECOVERY(3,
sdev_printk(KERN_INFO, sdev,
"%s: Sending BDR\n", current->comm));
- rtn = scsi_try_bus_device_reset(bdr_scmd);
+ rtn = scsi_try_bus_device_reset(sdev);
if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
if (!scsi_device_online(sdev) ||
rtn == FAST_IO_FAIL ||
@@ -1495,7 +1504,7 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
shost_printk(KERN_INFO, shost,
"%s: Sending target reset to target %d\n",
current->comm, id));
- rtn = scsi_try_target_reset(scmd);
+ rtn = scsi_try_target_reset(shost, scsi_target(scmd->device));
if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, shost,
@@ -1570,7 +1579,7 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
shost_printk(KERN_INFO, shost,
"%s: Sending BRST chan: %d\n",
current->comm, channel));
- rtn = scsi_try_bus_reset(chan_scmd);
+ rtn = scsi_try_bus_reset(shost, channel);
if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
if (channel == scmd_channel(scmd)) {
@@ -1608,15 +1617,12 @@ static int scsi_eh_host_reset(struct Scsi_Host *shost,
int rtn;

if (!list_empty(work_q)) {
- scmd = list_entry(work_q->next,
- struct scsi_cmnd, eh_entry);
-
SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, shost,
"%s: Sending HRST\n",
current->comm));

- rtn = scsi_try_host_reset(scmd);
+ rtn = scsi_try_host_reset(shost);
if (rtn == SUCCESS) {
list_splice_init(work_q, &check_list);
} else if (rtn == FAST_IO_FAIL) {
@@ -2221,7 +2227,7 @@ void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)

__shost_for_each_device(sdev, shost) {
if (channel == sdev_channel(sdev))
- __scsi_report_device_reset(sdev, NULL);
+ __scsi_report_device_reset(sdev);
}
}
EXPORT_SYMBOL(scsi_report_bus_reset);
@@ -2255,16 +2261,11 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
__shost_for_each_device(sdev, shost) {
if (channel == sdev_channel(sdev) &&
target == sdev_id(sdev))
- __scsi_report_device_reset(sdev, NULL);
+ __scsi_report_device_reset(sdev);
}
}
EXPORT_SYMBOL(scsi_report_device_reset);

-static void
-scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
-{
-}
-
/**
* scsi_ioctl_reset: explicitly reset a host/bus/target/device
* @dev: scsi_device to operate on
@@ -2273,9 +2274,7 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
int
scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
{
- struct scsi_cmnd *scmd;
struct Scsi_Host *shost = dev->host;
- struct request *rq;
unsigned long flags;
int error = 0, rtn, val;

@@ -2290,24 +2289,6 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
return -EIO;

error = -EIO;
- rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) +
- shost->hostt->cmd_size, GFP_KERNEL);
- if (!rq)
- goto out_put_autopm_host;
- blk_rq_init(NULL, rq);
-
- scmd = (struct scsi_cmnd *)(rq + 1);
- scsi_init_command(dev, scmd);
- scmd->request = rq;
- scmd->cmnd = scsi_req(rq)->cmd;
-
- scmd->scsi_done = scsi_reset_provider_done_command;
- memset(&scmd->sdb, 0, sizeof(scmd->sdb));
-
- scmd->cmd_len = 0;
-
- scmd->sc_data_direction = DMA_BIDIRECTIONAL;
-
spin_lock_irqsave(shost->host_lock, flags);
shost->tmf_in_progress = 1;
spin_unlock_irqrestore(shost->host_lock, flags);
@@ -2317,22 +2298,22 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
rtn = SUCCESS;
break;
case SG_SCSI_RESET_DEVICE:
- rtn = scsi_try_bus_device_reset(scmd);
+ rtn = scsi_try_bus_device_reset(dev);
if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
break;
/* FALLTHROUGH */
case SG_SCSI_RESET_TARGET:
- rtn = scsi_try_target_reset(scmd);
+ rtn = scsi_try_target_reset(shost, scsi_target(dev));
if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
break;
/* FALLTHROUGH */
case SG_SCSI_RESET_BUS:
- rtn = scsi_try_bus_reset(scmd);
+ rtn = scsi_try_bus_reset(shost, dev->channel);
if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
break;
/* FALLTHROUGH */
case SG_SCSI_RESET_HOST:
- rtn = scsi_try_host_reset(scmd);
+ rtn = scsi_try_host_reset(shost);
if (rtn == SUCCESS)
break;
default:
@@ -2357,11 +2338,6 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)

wake_up(&shost->host_wait);
scsi_run_host_queues(shost);
-
- scsi_put_command(scmd);
- kfree(rq);
-
-out_put_autopm_host:
scsi_autopm_put_host(shost);
return error;
}
--
1.8.5.6