/*
* scsi_error.c Copyright (C) 1997 Eric Youngdale
*
* SCSI error/timeout handling
* Initial versions: Eric Youngdale. Based upon conversations with
* Leonard Zubkoff and David Miller at Linux Expo,
* ideas originating from all over the place.
*
* Restructured scsi_unjam_host and associated functions.
* September 04, 2002 Mike Anderson (andmike@us.ibm.com)
*
* Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
* minor cleanups.
* September 30, 2002 Mike Anderson (andmike@us.ibm.com)
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/blk.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/smp_lock.h>
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include "scsi.h"
#include "hosts.h"
#include <scsi/scsi_ioctl.h> /* grr */
/*
* We must always allow SHUTDOWN_SIGS. Even if we are not a module,
* the host drivers that we are using may be loaded as modules, and
* when we unload these, we need to ensure that the error handler thread
* can be shut down.
*
* Note - when we unload a module, we send a SIGHUP. We mustn't
* enable SIGTERM, as this is how the init shuts things down when you
* go to single-user mode. For that matter, init also sends SIGKILL,
* so we mustn't enable that one either. We use SIGHUP instead. Other
* options would be SIGPWR, I suppose.
*/
#define SHUTDOWN_SIGS (sigmask(SIGHUP))
#ifdef DEBUG
#define SENSE_TIMEOUT SCSI_TIMEOUT
#else
#define SENSE_TIMEOUT (10*HZ)
#endif
/*
* These should *probably* be handled by the host itself.
* Since it is allowed to sleep, it probably should.
*/
#define BUS_RESET_SETTLE_TIME 10*HZ
#define HOST_RESET_SETTLE_TIME 10*HZ
/**
* scsi_add_timer - Start timeout timer for a single scsi command.
* @scmd: scsi command that is about to start running.
* @timeout: amount of time to allow this command to run.
* @complete: timeout function to call if timer isn't canceled.
*
* Notes:
* This should be turned into an inline function. Each scsi command
* has it's own timer, and as it is added to the queue, we set up the
* timer. When the command completes, we cancel the timer. Pretty
* simple, really, especially compared to the old way of handling this
* crap.
**/
void scsi_add_timer(Scsi_Cmnd *scmd, int timeout, void (*complete)
(Scsi_Cmnd *))
{
/*
* If the clock was already running for this command, then
* first delete the timer. The timer handling code gets rather
* confused if we don't do this.
*/
if (scmd->eh_timeout.function != NULL) {
del_timer(&scmd->eh_timeout);
}
scmd->eh_timeout.data = (unsigned long) scmd;
scmd->eh_timeout.expires = jiffies + timeout;
scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
" %d, (%p)\n", __FUNCTION__,
scmd, timeout, complete));
add_timer(&scmd->eh_timeout);
}
/**
* scsi_delete_timer - Delete/cancel timer for a given function.
* @scmd: Cmd that we are canceling timer for
*
* Notes:
* This should be turned into an inline function.
*
* Return value:
* 1 if we were able to detach the timer. 0 if we blew it, and the
* timer function has already started to run.
**/
int scsi_delete_timer(Scsi_Cmnd *scmd)
{
int rtn;
rtn = del_timer(&scmd->eh_timeout);
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
" rtn: %d\n", __FUNCTION__,
scmd, rtn));
scmd->eh_timeout.data = (unsigned long) NULL;
scmd->eh_timeout.function = NULL;
return rtn;
}
/**
* scsi_times_out - Timeout function for normal scsi commands.
* @scmd: Cmd that is timing out.
*
* Notes:
* We do not need to lock this. There is the potential for a race
* only in that the normal completion handling might run, but if the
* normal completion function determines that the timer has already
* fired, then it mustn't do anything.
**/
void scsi_times_out(Scsi_Cmnd *scmd)
{
/* Set the serial_number_at_timeout to the current serial_number */
scmd->serial_number_at_timeout = scmd->serial_number;
scsi_eh_eflags_set(scmd, SCSI_EH_CMD_TIMEOUT | SCSI_EH_CMD_ERR);
if( scmd->host->eh_wait == NULL ) {
panic("Error handler thread not present at %p %p %s %d",
scmd, scmd->host, __FILE__, __LINE__);
}
scsi_host_failed_inc_and_test(scmd->host);
SCSI_LOG_TIMEOUT(3, printk("Command timed out active=%d busy=%d "
" failed=%d\n",
atomic_read(&scmd->host->host_active),
scmd->host->host_busy,
scmd->host->host_failed));
}
/**
* scsi_block_when_processing_errors - Prevent cmds from being queued.
* @sdev: Device on which we are performing recovery.
*
* Description:
* We block until the host is out of error recovery, and then check to
* see whether the host or the device is offline.
*
* Return value:
* FALSE when dev was taken offline by error recovery. TRUE OK to
* proceed.
**/
int scsi_block_when_processing_errors(Scsi_Device *sdev)
{
SCSI_SLEEP(&sdev->host->host_wait, sdev->host->in_recovery);
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
sdev->online));
return sdev->online;
}
#if CONFIG_SCSI_LOGGING
/**
* scsi_eh_prt_fail_stats - Log info on failures.
* @sc_list: List for failed cmds.
* @shost: scsi host being recovered.
**/
static void scsi_eh_prt_fail_stats(Scsi_Cmnd *sc_list, struct Scsi_Host *shost)
{
Scsi_Cmnd *scmd;
Scsi_Device *sdev;
int total_failures = 0;
int cmd_failed = 0;
int cmd_timed_out = 0;
int devices_failed = 0;
for (sdev = shost->host_queue; sdev; sdev = sdev->next) {
for (scmd = sc_list; scmd; scmd = scmd->bh_next) {
if (scmd->device == sdev) {
++total_failures;
if (scsi_eh_eflags_chk(scmd,
SCSI_EH_CMD_TIMEOUT))
++cmd_timed_out;
else
++cmd_failed;
}
}
if (cmd_timed_out || cmd_failed) {
SCSI_LOG_ERROR_RECOVERY(3,
printk("%s: %d:%d:%d:%d cmds failed: %d,"
" timedout: %d\n",
__FUNCTION__, shost->host_no,
sdev->channel, sdev->id, sdev->lun,
cmd_failed, cmd_timed_out));
cmd_timed_out = 0;
cmd_failed = 0;
++devices_failed;
}
}
SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
" devices require eh work\n",
total_failures, devices_failed));
}
#endif
/**
* scsi_eh_get_failed - Gather failed cmds.
* @sc_list: A pointer to a list for failed cmds.
* @shost: Scsi host being recovered.
*
* XXX Add opaque interator for device / shost. Investigate direct
* addition to per eh list on error allowing skipping of this step.
**/
static void scsi_eh_get_failed(Scsi_Cmnd **sc_list, struct Scsi_Host *shost)
{
int found;
Scsi_Device *sdev;
Scsi_Cmnd *scmd;
for (found = 0, sdev = shost->host_queue; sdev; sdev = sdev->next) {
for (scmd = sdev->device_queue; scmd; scmd = scmd->next) {
if (scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR)) {
scmd->bh_next = *sc_list;
*sc_list = scmd;
found++;
} else {
/*
* FIXME Verify how this can happen and if
* this is still needed??
*/
if (scmd->state != SCSI_STATE_INITIALIZING
&& scmd->state != SCSI_STATE_UNUSED) {
/*
* Rats. Something is still floating
* around out there This could be the
* result of the fact that the upper level
* drivers are still frobbing commands
* that might have succeeded. There are
* two outcomes. One is that the command
* block will eventually be freed, and the
* other one is that the command will be
* queued and will be finished along the
* way.
*/
SCSI_LOG_ERROR_RECOVERY(1, printk("Error hdlr"
" prematurely woken"
" cmds still active"
" (%p %x %d)\n",
scmd, scmd->state,
scmd->target));
}
}
}
}
SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(*sc_list, shost));
if (shost->host_failed != found)
printk(KERN_ERR "%s: host_failed: %d != found: %d\n",
__FUNCTION__, shost->host_failed, found);
}
/**
* scsi_check_sense - Examine scsi cmd sense
* @scmd: Cmd to have sense checked.
*
* Return value:
* SUCCESS or FAILED or NEEDS_RETRY
**/
static int scsi_check_sense(Scsi_Cmnd *scmd)
{
if (!SCSI_SENSE_VALID(scmd)) {
return FAILED;
}
if (scmd->sense_buffer[2] & 0xe0)
return SUCCESS;
switch (scmd->sense_buffer[2] & 0xf) {
case NO_SENSE:
return SUCCESS;
case RECOVERED_ERROR:
return /* soft_error */ SUCCESS;
case ABORTED_COMMAND:
return NEEDS_RETRY;
case NOT_READY:
case UNIT_ATTENTION:
/*
* if we are expecting a cc/ua because of a bus reset that we
* performed, treat this just as a retry. otherwise this is
* information that we should pass up to the upper-level driver
* so that we can deal with it there.
*/
if (scmd->device->expecting_cc_ua) {
scmd->device->expecting_cc_ua = 0;
return NEEDS_RETRY;
}
/*
* if the device is in the process of becoming ready, we
* should retry.
*/
if ((scmd->sense_buffer[12] == 0x04) &&
(scmd->sense_buffer[13] == 0x01)) {
return NEEDS_RETRY;
}
return SUCCESS;
/* these three are not supported */
case COPY_ABORTED:
case VOLUME_OVERFLOW:
case MISCOMPARE:
return SUCCESS;
case MEDIUM_ERROR:
return NEEDS_RETRY;
case ILLEGAL_REQUEST:
case BLANK_CHECK:
case DATA_PROTECT:
case HARDWARE_ERROR:
default:
return SUCCESS;
}
}
/**
* scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
* @scmd: SCSI cmd to examine.
*
* Notes:
* This is *only* called when we are examining the status of commands
* queued during error recovery. the main difference here is that we
* don't allow for the possibility of retries here, and we are a lot
* more restrictive about what we consider acceptable.
**/
static int scsi_eh_completed_normally(Scsi_Cmnd *scmd)
{
/*
* first check the host byte, to see if there is anything in there
* that would indicate what we need to do.
*/
if (host_byte(scmd->result) == DID_RESET) {
if (scmd->flags & IS_RESETTING) {
/*
* ok, this is normal. we don't know whether in fact
* the command in question really needs to be rerun
* or not - if this was the original data command then
* the answer is yes, otherwise we just flag it as
* SUCCESS.
*/
scmd->flags &= ~IS_RESETTING;
return NEEDS_RETRY;
}
/*
* rats. we are already in the error handler, so we now
* get to try and figure out what to do next. if the sense
* is valid, we have a pretty good idea of what to do.
* if not, we mark it as FAILED.
*/
return scsi_check_sense(scmd);
}
if (host_byte(scmd->result) != DID_OK) {
return FAILED;
}
/*
* next, check the message byte.
*/
if (msg_byte(scmd->result) != COMMAND_COMPLETE) {
return FAILED;
}
/*
* now, check the status byte to see if this indicates
* anything special.
*/
switch (status_byte(scmd->result)) {
case GOOD:
case COMMAND_TERMINATED:
return SUCCESS;
case CHECK_CONDITION:
return scsi_check_sense(scmd);
case CONDITION_GOOD:
case INTERMEDIATE_GOOD:
case INTERMEDIATE_C_GOOD:
/*
* who knows? FIXME(eric)
*/
return SUCCESS;
case BUSY:
case QUEUE_FULL:
case RESERVATION_CONFLICT:
default:
return FAILED;
}
return FAILED;
}
/**
* scsi_eh_times_out - timeout function for error handling.
* @scmd: Cmd that is timing out.
*
* Notes:
* During error handling, the kernel thread will be sleeping waiting
* for some action to complete on the device. our only job is to
* record that it timed out, and to wake up the thread.
**/
static void scsi_eh_times_out(Scsi_Cmnd *scmd)
{
scsi_eh_eflags_set(scmd, SCSI_EH_REC_TIMEOUT);
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__,
scmd));
if (scmd->host->eh_action != NULL)
up(scmd->host->eh_action);
else
printk("%s: eh_action NULL\n", __FUNCTION__);
}
/**
* scsi_eh_done - Completion function for error handling.
* @scmd: Cmd that is done.
**/
static void scsi_eh_done(Scsi_Cmnd *scmd)
{
int rtn;
/*
* if the timeout handler is already running, then just set the
* flag which says we finished late, and return. we have no
* way of stopping the timeout handler from running, so we must
* always defer to it.
*/
rtn = del_timer(&scmd->eh_timeout);
if (!rtn) {
return;
}
scmd->request->rq_status = RQ_SCSI_DONE;
scmd->owner = SCSI_OWNER_ERROR_HANDLER;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
__FUNCTION__, scmd, scmd->result));
if (scmd->host->eh_action != NULL)
up(scmd->host->eh_action);
}
/**
* scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
* @scmd: SCSI Cmd to send.
* @timeout: Timeout for cmd.
*
* Notes:
* The initialization of the structures is quite a bit different in
* this case, and furthermore, there is a different completion handler
* vs scsi_dispatch_cmd.
* Return value:
* SUCCESS or FAILED or NEEDS_RETRY
**/
static int scsi_send_eh_cmnd(Scsi_Cmnd *scmd, int timeout)
{
unsigned long flags;
struct Scsi_Host *host = scmd->host;
int rtn = SUCCESS;
ASSERT_LOCK(host->host_lock, 0);
/*
* we will use a queued command if possible, otherwise we will
* emulate the queuing and calling of completion function ourselves.
*/
scmd->owner = SCSI_OWNER_LOWLEVEL;
if (scmd->device->scsi_level <= SCSI_2)
scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
(scmd->lun << 5 & 0xe0);
if (host->can_queue) {
DECLARE_MUTEX_LOCKED(sem);
scsi_add_timer(scmd, timeout, scsi_eh_times_out);
/*
* set up the semaphore so we wait for the command to complete.
*/
scmd->host->eh_action = &sem;
scmd->request->rq_status = RQ_SCSI_BUSY;
spin_lock_irqsave(scmd->host->host_lock, flags);
host->hostt->queuecommand(scmd, scsi_eh_done);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
down(&sem);
scmd->host->eh_action = NULL;
/*
* see if timeout. if so, tell the host to forget about it.
* in other words, we don't want a callback any more.
*/
if (scsi_eh_eflags_chk(scmd, SCSI_EH_REC_TIMEOUT)) {
scsi_eh_eflags_clr(scmd, SCSI_EH_REC_TIMEOUT);
scmd->owner = SCSI_OWNER_LOWLEVEL;
/*
* as far as the low level driver is
* concerned, this command is still active, so
* we must give the low level driver a chance
* to abort it. (db)
*
* FIXME(eric) - we are not tracking whether we could
* abort a timed out command or not. not sure how
* we should treat them differently anyways.
*/
spin_lock_irqsave(scmd->host->host_lock, flags);
if (scmd->host->hostt->eh_abort_handler)
scmd->host->hostt->eh_abort_handler(scmd);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
scmd->request->rq_status = RQ_SCSI_DONE;
scmd->owner = SCSI_OWNER_ERROR_HANDLER;
rtn = FAILED;
}
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
__FUNCTION__, scmd, rtn));
} else {
int temp;
/*
* we damn well had better never use this code. there is no
* timeout protection here, since we would end up waiting in
* the actual low level driver, we don't know how to wake it up.
*/
spin_lock_irqsave(host->host_lock, flags);
temp = host->hostt->command(scmd);
spin_unlock_irqrestore(host->host_lock, flags);
scmd->result = temp;
/* fall through to code below to examine status. */
}
/*
* now examine the actual status codes to see whether the command
* actually did complete normally.
*/
if (rtn == SUCCESS) {
int rtn = scsi_eh_completed_normally(scmd);
SCSI_LOG_ERROR_RECOVERY(3,
printk("%s: scsi_eh_completed_normally %x\n",
__FUNCTION__, rtn));
switch (rtn) {
case SUCCESS:
case NEEDS_RETRY:
case FAILED:
break;
default:
rtn = FAILED;
break;
}
}
return rtn;
}
/**
* scsi_request_sense - Request sense data from a particular target.
* @scmd: SCSI cmd for request sense.
*
* Notes:
* Some hosts automatically obtain this information, others require
* that we obtain it on our own. This function will *not* return until
* the command either times out, or it completes.
**/
static int scsi_request_sense(Scsi_Cmnd *scmd)
{
static unsigned char generic_sense[6] =
{REQUEST_SENSE, 0, 0, 0, 255, 0};
unsigned char scsi_result0[256], *scsi_result = NULL;
int saved_result;
int rtn;
memcpy((void *) scmd->cmnd, (void *) generic_sense,
sizeof(generic_sense));
scsi_result = (!scmd->host->hostt->unchecked_isa_dma)
? &scsi_result0[0] : kmalloc(512, GFP_ATOMIC | GFP_DMA);
if (scsi_result == NULL) {
printk("%s: cannot allocate scsi_result.\n", __FUNCTION__);
return FAILED;
}
/*
* zero the sense buffer. some host adapters automatically always
* request sense, so it is not a good idea that
* scmd->request_buffer and scmd->sense_buffer point to the same
* address (db). 0 is not a valid sense code.
*/
memset((void *) scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
memset((void *) scsi_result, 0, 256);
saved_result = scmd->result;
scmd->request_buffer = scsi_result;
scmd->request_bufflen = 256;
scmd->use_sg = 0;
scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
scmd->sc_data_direction = SCSI_DATA_READ;
scmd->underflow = 0;
rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
/* last chance to have valid sense data */
if (!SCSI_SENSE_VALID(scmd))
memcpy((void *) scmd->sense_buffer,
scmd->request_buffer,
sizeof(scmd->sense_buffer));
if (scsi_result != &scsi_result0[0] && scsi_result != NULL)
kfree(scsi_result);
/*
* when we eventually call scsi_finish, we really wish to complete
* the original request, so let's restore the original data. (db)
*/
scsi_setup_cmd_retry(scmd);
scmd->result = saved_result;
/*
* hey, we are done. let's look to see what happened.
*/
return rtn;
}
/**
* scsi_eh_retry_cmd - Retry the original command
* @scmd: Original failed SCSI cmd.
*
* Notes:
* This function will *not* return until the command either times out,
* or it completes.
**/
static int scsi_eh_retry_cmd(Scsi_Cmnd *scmd)
{
int rtn = SUCCESS;
for (; scmd->retries < scmd->allowed; scmd->retries++) {
scsi_setup_cmd_retry(scmd);
rtn = scsi_send_eh_cmnd(scmd, scmd->timeout_per_command);
if (rtn != NEEDS_RETRY)
break;
}
return rtn;
}
/**
* scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
* @scmd: Original SCSI cmd that eh has finished.
* @shost: SCSI host that cmd originally failed on.
*
* Notes:
* We don't want to use the normal command completion while we are are
* still handling errors - it may cause other commands to be queued,
* and that would disturb what we are doing. thus we really want to
* keep a list of pending commands for final completion, and once we
* are ready to leave error handling we handle completion for real.
**/
static void scsi_eh_finish_cmd(Scsi_Cmnd *scmd, struct Scsi_Host *shost)
{
shost->host_failed--;
scmd->state = SCSI_STATE_BHQUEUE;
scsi_eh_eflags_clr_all(scmd);
/*
* set this back so that the upper level can correctly free up
* things.
*/
scsi_setup_cmd_retry(scmd);
}
/**
* scsi_eh_get_sense - Get device sense data.
* @sc_todo: list of cmds that have failed.
* @shost: scsi host being recovered.
*
* Description:
* See if we need to request sense information. if so, then get it
* now, so we have a better idea of what to do.
*
*
* Notes:
* This has the unfortunate side effect that if a shost adapter does
* not automatically request sense information, that we end up shutting
* it down before we request it. All shosts should be doing this
* anyways, so for now all I have to say is tough noogies if you end up
* in here. On second thought, this is probably a good idea. We
* *really* want to give authors an incentive to automatically request
* this.
*
* In 2.5 this capability will be going away.
**/
static int scsi_eh_get_sense(Scsi_Cmnd *sc_todo, struct Scsi_Host *shost)
{
int rtn;
Scsi_Cmnd *scmd;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: checking to see if we need"
" to request sense\n",
__FUNCTION__));
for (scmd = sc_todo; scmd; scmd = scmd->bh_next) {
if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_FAILED) ||
SCSI_SENSE_VALID(scmd))
continue;
SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense"
" for tgt: %d\n",
__FUNCTION__, scmd->target));
rtn = scsi_request_sense(scmd);
if (rtn != SUCCESS)
continue;
SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
" result %x\n", scmd,
scmd->result));
SCSI_LOG_ERROR_RECOVERY(3, print_sense("bh", scmd));
rtn = scsi_decide_disposition(scmd);
/*
* if the result was normal, then just pass it along to the
* upper level.
*/
if (rtn == SUCCESS)
scsi_eh_finish_cmd(scmd, shost);
if (rtn != NEEDS_RETRY)
continue;
/*
* we only come in here if we want to retry a
* command. the test to see whether the command
* should be retried should be keeping track of the
* number of tries, so we don't end up looping, of
* course.
*/
scmd->state = NEEDS_RETRY;
rtn = scsi_eh_retry_cmd(scmd);
if (rtn != SUCCESS)
continue;
/*
* we eventually hand this one back to the top level.
*/
scsi_eh_finish_cmd(scmd, shost);
}
return shost->host_failed;
}
/**
* scsi_try_to_abort_cmd - Ask host to abort a running command.
* @scmd: SCSI cmd to abort from Lower Level.
*
* Notes:
* This function will not return until the user's completion function
* has been called. there is no timeout on this operation. if the
* author of the low-level driver wishes this operation to be timed,
* they can provide this facility themselves. helper functions in
* scsi_error.c can be supplied to make this easier to do.
**/
static int scsi_try_to_abort_cmd(Scsi_Cmnd *scmd)
{
int rtn = FAILED;
unsigned long flags;
if (scmd->host->hostt->eh_abort_handler == NULL) {
return rtn;
}
/*
* scsi_done was called just after the command timed out and before
* we had a chance to process it. (db)
*/
if (scmd->serial_number == 0)
return SUCCESS;
scmd->owner = SCSI_OWNER_LOWLEVEL;
spin_lock_irqsave(scmd->host->host_lock, flags);
rtn = scmd->host->hostt->eh_abort_handler(scmd);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
return rtn;
}
/**
* scsi_eh_tur - Send TUR to device.
* @scmd: Scsi cmd to send TUR
*
* Return value:
* 0 - Device is ready. 1 - Device NOT ready.
**/
static int scsi_eh_tur(Scsi_Cmnd *scmd)
{
static unsigned char tur_command[6] =
{TEST_UNIT_READY, 0, 0, 0, 0, 0};
int rtn;
int retry_cnt = 1;
retry_tur:
memcpy((void *) scmd->cmnd, (void *) tur_command,
sizeof(tur_command));
/*
* zero the sense buffer. the scsi spec mandates that any
* untransferred sense data should be interpreted as being zero.
*/
memset((void *) scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
scmd->request_buffer = NULL;
scmd->request_bufflen = 0;
scmd->use_sg = 0;
scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
scmd->underflow = 0;
scmd->sc_data_direction = SCSI_DATA_NONE;
rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
/*
* when we eventually call scsi_finish, we really wish to complete
* the original request, so let's restore the original data. (db)
*/
scsi_setup_cmd_retry(scmd);
/*
* hey, we are done. let's look to see what happened.
*/
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
__FUNCTION__, scmd, rtn));
if (rtn == SUCCESS)
return 0;
else if (rtn == NEEDS_RETRY)
if (retry_cnt--)
goto retry_tur;
return 1;
}
/**
* scsi_eh_abort_cmd - abort a timed-out cmd.
* @sc_todo: A list of cmds that have failed.
* @shost: scsi host being recovered.
*
* Decription:
* Try and see whether or not it makes sense to try and abort the
* running command. this only works out to be the case if we have one
* command that has timed out. if the command simply failed, it makes
* no sense to try and abort the command, since as far as the shost
* adapter is concerned, it isn't running.
**/
static int scsi_eh_abort_cmd(Scsi_Cmnd *sc_todo, struct Scsi_Host *shost)
{
int rtn;
Scsi_Cmnd *scmd;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: checking to see if we need"
" to abort cmd\n", __FUNCTION__));
for (scmd = sc_todo; scmd; scmd = scmd->bh_next) {
if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_TIMEOUT))
continue;
rtn = scsi_try_to_abort_cmd(scmd);
if (rtn == SUCCESS) {
if (!scsi_eh_tur(scmd)) {
rtn = scsi_eh_retry_cmd(scmd);
if (rtn == SUCCESS)
scsi_eh_finish_cmd(scmd, shost);
}
}
}
return shost->host_failed;
}
/**
* scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
* @scmd: SCSI cmd used to send BDR
*
* Notes:
* There is no timeout for this operation. if this operation is
* unreliable for a given host, then the host itself needs to put a
* timer on it, and set the host back to a consistent state prior to
* returning.
**/
static int scsi_try_bus_device_reset(Scsi_Cmnd *scmd)
{
unsigned long flags;
int rtn = FAILED;
if (scmd->host->hostt->eh_device_reset_handler == NULL) {
return rtn;
}
scmd->owner = SCSI_OWNER_LOWLEVEL;
spin_lock_irqsave(scmd->host->host_lock, flags);
rtn = scmd->host->hostt->eh_device_reset_handler(scmd);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
if (rtn == SUCCESS) {
scmd->device->was_reset = 1;
scmd->device->expecting_cc_ua = 1;
}
return rtn;
}
/**
* scsi_eh_bus_device_reset - send bdr is needed
* @sc_todo: a list of cmds that have failed.
* @shost: scsi host being recovered.
*
* Notes:
* Try a bus device reset. still, look to see whether we have multiple
* devices that are jammed or not - if we have multiple devices, it
* makes no sense to try bus_device_reset - we really would need to try
* a bus_reset instead.
**/
static int scsi_eh_bus_device_reset(Scsi_Cmnd *sc_todo, struct Scsi_Host *shost)
{
int rtn;
Scsi_Cmnd *scmd;
Scsi_Device *sdev;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Trying BDR\n", __FUNCTION__));
for (sdev = shost->host_queue; sdev; sdev = sdev->next) {
for (scmd = sc_todo; scmd; scmd = scmd->bh_next)
if ((scmd->device == sdev) &&
scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR))
break;
if (!scmd)
continue;
/*
* ok, we have a device that is having problems. try and send
* a bus device reset to it.
*/
rtn = scsi_try_bus_device_reset(scmd);
if ((rtn == SUCCESS) && (!scsi_eh_tur(scmd)))
for (scmd = sc_todo; scmd; scmd = scmd->bh_next)
if ((scmd->device == sdev) &&
scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR)) {
rtn = scsi_eh_retry_cmd(scmd);
if (rtn == SUCCESS)
scsi_eh_finish_cmd(scmd, shost);
}
}
return shost->host_failed;
}
/**
* scsi_try_bus_reset - ask host to perform a bus reset
* @scmd: SCSI cmd to send bus reset.
**/
static int scsi_try_bus_reset(Scsi_Cmnd *scmd)
{
unsigned long flags;
int rtn;
Scsi_Device *sdev;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
__FUNCTION__));
scmd->owner = SCSI_OWNER_LOWLEVEL;
scmd->serial_number_at_timeout = scmd->serial_number;
if (scmd->host->hostt->eh_bus_reset_handler == NULL)
return FAILED;
spin_lock_irqsave(scmd->host->host_lock, flags);
rtn = scmd->host->hostt->eh_bus_reset_handler(scmd);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
if (rtn == SUCCESS) {
scsi_sleep(BUS_RESET_SETTLE_TIME);
/*
* Mark all affected devices to expect a unit attention.
*/
for (sdev = scmd->host->host_queue; sdev; sdev = sdev->next)
if (scmd->channel == sdev->channel) {
sdev->was_reset = 1;
sdev->expecting_cc_ua = 1;
}
}
return rtn;
}
/**
* scsi_try_host_reset - ask host adapter to reset itself
* @scmd: SCSI cmd to send hsot reset.
**/
static int scsi_try_host_reset(Scsi_Cmnd *scmd)
{
unsigned long flags;
int rtn;
Scsi_Device *sdev;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
__FUNCTION__));
scmd->owner = SCSI_OWNER_LOWLEVEL;
scmd->serial_number_at_timeout = scmd->serial_number;
if (scmd->host->hostt->eh_host_reset_handler == NULL)
return FAILED;
spin_lock_irqsave(scmd->host->host_lock, flags);
rtn = scmd->host->hostt->eh_host_reset_handler(scmd);
spin_unlock_irqrestore(scmd->host->host_lock, flags);
if (rtn == SUCCESS) {
scsi_sleep(HOST_RESET_SETTLE_TIME);
/*
* Mark all affected devices to expect a unit attention.
*/
for (sdev = scmd->host->host_queue; sdev; sdev = sdev->next)
if (scmd->channel == sdev->channel) {
sdev->was_reset = 1;
sdev->expecting_cc_ua = 1;
}
}
return rtn;
}
/**
* scsi_eh_bus_host_reset - send a bus reset and on failure try host reset
* @sc_todo: a list of cmds that have failed.
* @shost: scsi host being recovered.
**/
static int scsi_eh_bus_host_reset(Scsi_Cmnd *sc_todo, struct Scsi_Host *shost)
{
int rtn;
Scsi_Cmnd *scmd;
Scsi_Cmnd *chan_scmd;
unsigned int channel;
/*
* if we ended up here, we have serious problems. the only thing left
* to try is a full bus reset. if someone has grabbed the bus and isn't
* letting go, then perhaps this will help.
*/
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Try Bus/Host RST\n",
__FUNCTION__));
/*
* we really want to loop over the various channels, and do this on
* a channel by channel basis. we should also check to see if any
* of the failed commands are on soft_reset devices, and if so, skip
* the reset.
*/
for (channel = 0; channel <= shost->max_channel; channel++) {
for (scmd = sc_todo; scmd; scmd = scmd->bh_next) {
if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR))
continue;
if (channel == scmd->channel) {
chan_scmd = scmd;
break;
/*
* FIXME add back in some support for
* soft_reset devices.
*/
}
}
if (!scmd)
continue;
/*
* we now know that we are able to perform a reset for the
* channel that scmd points to.
*/
rtn = scsi_try_bus_reset(scmd);
if (rtn != SUCCESS)
rtn = scsi_try_host_reset(scmd);
if (rtn == SUCCESS) {
for (scmd = sc_todo; scmd; scmd = scmd->bh_next) {
if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR)
|| channel != scmd->channel)
continue;
if (!scsi_eh_tur(scmd)) {
rtn = scsi_eh_retry_cmd(scmd);
if (rtn == SUCCESS)
scsi_eh_finish_cmd(scmd, shost);
}
}
}
}
return shost->host_failed;
}
/**
* scsi_eh_offline_sdevs - offline scsi devices that fail to recover
* @sc_todo: a list of cmds that have failed.
* @shost: scsi host being recovered.
*
**/
static void scsi_eh_offline_sdevs(Scsi_Cmnd *sc_todo, struct Scsi_Host *shost)
{
Scsi_Cmnd *scmd;
for (scmd = sc_todo; scmd; scmd = scmd->bh_next) {
if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CMD_ERR))
continue;
printk(KERN_INFO "%s: Device offlined - not"
" ready or command retry failed"
" after error recovery: host"
" %d channel %d id %d lun %d\n",
__FUNCTION__, shost->host_no,
scmd->device->channel,
scmd->device->id,
scmd->device->lun);
scmd->device->online = FALSE;
scsi_eh_finish_cmd(scmd, shost);
}
return;
}
/**
* scsi_sleep_done - timer function for scsi_sleep
* @sem: semphore to signal
*
**/
static
void scsi_sleep_done(struct semaphore *sem)
{
if (sem != NULL) {
up(sem);
}
}
/**
* scsi_sleep - sleep for specified timeout
* @timeout: timeout value
*
**/
void scsi_sleep(int timeout)
{
DECLARE_MUTEX_LOCKED(sem);
struct timer_list timer;
init_timer(&timer);
timer.data = (unsigned long) &sem;
timer.expires = jiffies + timeout;
timer.function = (void (*)(unsigned long)) scsi_sleep_done;
SCSI_LOG_ERROR_RECOVERY(5, printk("sleeping for timer tics %d\n",
timeout));
add_timer(&timer);
down(&sem);
del_timer(&timer);
}
/**
* scsi_decide_disposition - Disposition a cmd on return from LLD.
* @scmd: SCSI cmd to examine.
*
* Notes:
* This is *only* called when we are examining the status after sending
* out the actual data command. any commands that are queued for error
* recovery (i.e. test_unit_ready) do *not* come through here.
*
* When this routine returns failed, it means the error handler thread
* is woken. in cases where the error code indicates an error that
* doesn't require the error handler read (i.e. we don't need to
* abort/reset), then this function should return SUCCESS.
**/
int scsi_decide_disposition(Scsi_Cmnd *scmd)
{
int rtn;
/*
* if the device is offline, then we clearly just pass the result back
* up to the top level.
*/
if (scmd->device->online == FALSE) {
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
" as SUCCESS\n",
__FUNCTION__));
return SUCCESS;
}
/*
* first check the host byte, to see if there is anything in there
* that would indicate what we need to do.
*/
switch (host_byte(scmd->result)) {
case DID_PASSTHROUGH:
/*
* no matter what, pass this through to the upper layer.
* nuke this special code so that it looks like we are saying
* did_ok.
*/
scmd->result &= 0xff00ffff;
return SUCCESS;
case DID_OK:
/*
* looks good. drop through, and check the next byte.
*/
break;
case DID_NO_CONNECT:
case DID_BAD_TARGET:
case DID_ABORT:
/*
* note - this means that we just report the status back
* to the top level driver, not that we actually think
* that it indicates SUCCESS.
*/
return SUCCESS;
/*
* when the low level driver returns did_soft_error,
* it is responsible for keeping an internal retry counter
* in order to avoid endless loops (db)
*
* actually this is a bug in this function here. we should
* be mindful of the maximum number of retries specified
* and not get stuck in a loop.
*/
case DID_SOFT_ERROR:
goto maybe_retry;
case DID_ERROR:
if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
status_byte(scmd->result) == RESERVATION_CONFLICT)
/*
* execute reservation conflict processing code
* lower down
*/
break;
/* fallthrough */
case DID_BUS_BUSY:
case DID_PARITY:
goto maybe_retry;
case DID_TIME_OUT:
/*
* when we scan the bus, we get timeout messages for
* these commands if there is no device available.
* other hosts report did_no_connect for the same thing.
*/
if ((scmd->cmnd[0] == TEST_UNIT_READY ||
scmd->cmnd[0] == INQUIRY)) {
return SUCCESS;
} else {
return FAILED;
}
case DID_RESET:
/*
* in the normal case where we haven't initiated a reset,
* this is a failure.
*/
if (scmd->flags & IS_RESETTING) {
scmd->flags &= ~IS_RESETTING;
goto maybe_retry;
}
return SUCCESS;
default:
return FAILED;
}
/*
* next, check the message byte.
*/
if (msg_byte(scmd->result) != COMMAND_COMPLETE) {
return FAILED;
}
/*
* now, check the status byte to see if this indicates anything special.
*/
switch (status_byte(scmd->result)) {
case QUEUE_FULL:
/*
* the case of trying to send too many commands to a
* tagged queueing device.
*/
case BUSY:
/*
* device can't talk to us at the moment. Should only
* occur (SAM-3) when the task queue is empty, so will cause
* the empty queue handling to trigger a stall in the
* device.
*/
return ADD_TO_MLQUEUE;
case GOOD:
case COMMAND_TERMINATED:
return SUCCESS;
case CHECK_CONDITION:
rtn = scsi_check_sense(scmd);
if (rtn == NEEDS_RETRY) {
goto maybe_retry;
}
return rtn;
case CONDITION_GOOD:
case INTERMEDIATE_GOOD:
case INTERMEDIATE_C_GOOD:
/*
* who knows? FIXME(eric)
*/
return SUCCESS;
case RESERVATION_CONFLICT:
printk("scsi%d (%d,%d,%d) : reservation conflict\n",
scmd->host->host_no, scmd->channel,
scmd->device->id, scmd->device->lun);
return SUCCESS; /* causes immediate i/o error */
default:
return FAILED;
}
return FAILED;
maybe_retry:
if ((++scmd->retries) < scmd->allowed) {
return NEEDS_RETRY;
} else {
/*
* no more retries - report this one back to upper level.
*/
return SUCCESS;
}
}
/**
* scsi_eh_lock_done - done function for eh door lock request
* @scmd: SCSI command block for the door lock request
*
* Notes:
* We completed the asynchronous door lock request, and it has either
* locked the door or failed. We must free the command structures
* associated with this request.
**/
static void scsi_eh_lock_done(struct scsi_cmnd *scmd)
{
struct scsi_request *sreq = scmd->sc_request;
scmd->sc_request = NULL;
sreq->sr_command = NULL;
scsi_release_command(scmd);
scsi_release_request(sreq);
}
/**
* scsi_eh_lock_door - Prevent medium removal for the specified device
* @sdev: SCSI device to prevent medium removal
*
* Locking:
* We must be called from process context; scsi_allocate_request()
* may sleep.
*
* Notes:
* We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
* head of the devices request queue, and continue.
*
* Bugs:
* scsi_allocate_request() may sleep waiting for existing requests to
* be processed. However, since we haven't kicked off any request
* processing for this host, this may deadlock.
*
* If scsi_allocate_request() fails for what ever reason, we
* completely forget to lock the door.
**/
static void scsi_eh_lock_door(struct scsi_device *sdev)
{
struct scsi_request *sreq = scsi_allocate_request(sdev);
if (sreq == NULL) {
printk(KERN_ERR "%s: request allocate failed,"
"prevent media removal cmd not sent", __FUNCTION__);
return;
}
sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL;
sreq->sr_cmnd[1] = 0;
sreq->sr_cmnd[2] = 0;
sreq->sr_cmnd[3] = 0;
sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT;
sreq->sr_cmnd[5] = 0;
sreq->sr_data_direction = SCSI_DATA_NONE;
sreq->sr_bufflen = 0;
sreq->sr_buffer = NULL;
sreq->sr_allowed = 5;
sreq->sr_done = scsi_eh_lock_done;
sreq->sr_timeout_per_command = 10 * HZ;
sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
scsi_insert_special_req(sreq, 1);
}
/**
* scsi_restart_operations - restart io operations to the specified host.
* @shost: Host we are restarting.
*
* Notes:
* When we entered the error handler, we blocked all further i/o to
* this device. we need to 'reverse' this process.
**/
static void scsi_restart_operations(struct Scsi_Host *shost)
{
Scsi_Device *sdev;
unsigned long flags;
ASSERT_LOCK(shost->host_lock, 0);
/*
* If the door was locked, we need to insert a door lock request
* onto the head of the SCSI request queue for the device. There
* is no point trying to lock the door of an off-line device.
*/
for (sdev = shost->host_queue; sdev; sdev = sdev->next)
if (sdev->online && sdev->locked)
scsi_eh_lock_door(sdev);
/*
* next free up anything directly waiting upon the host. this
* will be requests for character device operations, and also for
* ioctls to queued block devices.
*/
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
__FUNCTION__));
wake_up(&shost->host_wait);
/*
* finally we need to re-initiate requests that may be pending. we will
* have had everything blocked while error handling is taking place, and
* now that error recovery is done, we will need to ensure that these
* requests are started.
*/
spin_lock_irqsave(shost->host_lock, flags);
for (sdev = shost->host_queue; sdev; sdev = sdev->next) {
request_queue_t *q = &sdev->request_queue;
if ((shost->can_queue > 0 &&
(shost->host_busy >= shost->can_queue))
|| (shost->host_blocked)
|| (shost->host_self_blocked)) {
break;
}
q->request_fn(q);
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
/**
* scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
* @shost: Host to unjam.
*
* Notes:
* When we come in here, we *know* that all commands on the bus have
* either completed, failed or timed out. we also know that no further
* commands are being sent to the host, so things are relatively quiet
* and we have freedom to fiddle with things as we wish.
*
* This is only the *default* implementation. it is possible for
* individual drivers to supply their own version of this function, and
* if the maintainer wishes to do this, it is strongly suggested that
* this function be taken as a template and modified. this function
* was designed to correctly handle problems for about 95% of the
* different cases out there, and it should always provide at least a
* reasonable amount of error recovery.
*
* Any command marked 'failed' or 'timeout' must eventually have
* scsi_finish_cmd() called for it. we do all of the retry stuff
* here, so when we restart the host after we return it should have an
* empty queue.
**/
static void scsi_unjam_host(struct Scsi_Host *shost)
{
Scsi_Cmnd *sc_todo = NULL;
Scsi_Cmnd *scmd;
/*
* Is this assert really ok anymore (andmike). Should we at least
* be using spin_lock_unlocked.
*/
ASSERT_LOCK(shost->host_lock, 0);
scsi_eh_get_failed(&sc_todo, shost);
if (scsi_eh_get_sense(sc_todo, shost))
if (scsi_eh_abort_cmd(sc_todo, shost))
if (scsi_eh_bus_device_reset(sc_todo, shost))
if (scsi_eh_bus_host_reset(sc_todo, shost))
scsi_eh_offline_sdevs(sc_todo, shost);
BUG_ON(shost->host_failed);
/*
* We are currently holding these things in a linked list - we
* didn't put them in the bottom half queue because we wanted to
* keep things quiet while we were working on recovery, and
* passing them up to the top level could easily cause the top
* level to try and queue something else again.
*
* start by marking that the host is no longer in error recovery.
*/
shost->in_recovery = 0;
/*
* take the list of commands, and stick them in the bottom half queue.
* the current implementation of scsi_done will do this for us - if need
* be we can create a special version of this function to do the
* same job for us.
*/
for (scmd = sc_todo; scmd; scmd = sc_todo) {
sc_todo = scmd->bh_next;
scmd->bh_next = NULL;
/*
* Oh, this is a vile hack. scsi_done() expects a timer
* to be running on the command. If there isn't, it assumes
* that the command has actually timed out, and a timer
* handler is running. That may well be how we got into
* this fix, but right now things are stable. We add
* a timer back again so that we can report completion.
* scsi_done() will immediately remove said timer from
* the command, and then process it.
*/
scsi_add_timer(scmd, 100, scsi_eh_times_out);
scsi_done(scmd);
}
}
/**
* scsi_error_handler - Handle errors/timeouts of SCSI cmds.
* @data: Host for which we are running.
*
* Notes:
* This is always run in the context of a kernel thread. The idea is
* that we start this thing up when the kernel starts up (one per host
* that we detect), and it immediately goes to sleep and waits for some
* event (i.e. failure). When this takes place, we have the job of
* trying to unjam the bus and restarting things.
**/
void scsi_error_handler(void *data)
{
struct Scsi_Host *shost = (struct Scsi_Host *) data;
int rtn;
DECLARE_MUTEX_LOCKED(sem);
/*
* We only listen to signals if the HA was loaded as a module.
* If the HA was compiled into the kernel, then we don't listen
* to any signals.
*/
siginitsetinv(¤t->blocked, SHUTDOWN_SIGS);
lock_kernel();
/*
* Flush resources
*/
daemonize();
/*
* Set the name of this process.
*/
sprintf(current->comm, "scsi_eh_%d", shost->host_no);
shost->eh_wait = &sem;
shost->ehandler = current;
unlock_kernel();
/*
* Wake up the thread that created us.
*/
SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent \n"));
up(shost->eh_notify);
while (1) {
/*
* If we get a signal, it means we are supposed to go
* away and die. This typically happens if the user is
* trying to unload a module.
*/
SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler sleeping\n"));
/*
* Note - we always use down_interruptible with the semaphore
* even if the module was loaded as part of the kernel. The
* reason is that down() will cause this thread to be counted
* in the load average as a running process, and down
* interruptible doesn't. Given that we need to allow this
* thread to die if the driver was loaded as a module, using
* semaphores isn't unreasonable.
*/
down_interruptible(&sem);
if (signal_pending(current))
break;
SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler waking up\n"));
shost->eh_active = 1;
/*
* We have a host that is failing for some reason. Figure out
* what we need to do to get it up and online again (if we can).
* If we fail, we end up taking the thing offline.
*/
if (shost->hostt->eh_strategy_handler != NULL) {
rtn = shost->hostt->eh_strategy_handler(shost);
} else {
scsi_unjam_host(shost);
}
shost->eh_active = 0;
/*
* Note - if the above fails completely, the action is to take
* individual devices offline and flush the queue of any
* outstanding requests that may have been pending. When we
* restart, we restart any I/O to any other devices on the bus
* which are still online.
*/
scsi_restart_operations(shost);
}
SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler exiting\n"));
/*
* Make sure that nobody tries to wake us up again.
*/
shost->eh_wait = NULL;
/*
* Knock this down too. From this point on, the host is flying
* without a pilot. If this is because the module is being unloaded,
* that's fine. If the user sent a signal to this thing, we are
* potentially in real danger.
*/
shost->in_recovery = 0;
shost->eh_active = 0;
shost->ehandler = NULL;
/*
* If anyone is waiting for us to exit (i.e. someone trying to unload
* a driver), then wake up that process to let them know we are on
* the way out the door. This may be overkill - I *think* that we
* could probably just unload the driver and send the signal, and when
* the error handling thread wakes up that it would just exit without
* needing to touch any memory associated with the driver itself.
*/
if (shost->eh_notify != NULL)
up(shost->eh_notify);
}
/**
* scsi_new_reset - Send reset to a bus or device at any phase.
* @scmd: Cmd to send reset with (usually a dummy)
* @flag: Reset type.
*
* Description:
* This is used by the SCSI Generic driver to provide Bus/Device reset
* capability.
*
* Return value:
* SUCCESS/FAILED.
**/
int scsi_new_reset(Scsi_Cmnd *scmd, int flag)
{
int rtn;
switch(flag) {
case SCSI_TRY_RESET_DEVICE:
rtn = scsi_try_bus_device_reset(scmd);
if (rtn == SUCCESS)
break;
/* FALLTHROUGH */
case SCSI_TRY_RESET_BUS:
rtn = scsi_try_bus_reset(scmd);
if (rtn == SUCCESS)
break;
/* FALLTHROUGH */
case SCSI_TRY_RESET_HOST:
rtn = scsi_try_host_reset(scmd);
break;
default:
rtn = FAILED;
}
return rtn;
}