Commit 8b00c3d5 authored by Finn Thain's avatar Finn Thain Committed by Martin K. Petersen

ncr5380: Implement new eh_abort_handler

Introduce a new eh_abort_handler implementation. This one attempts to
follow all of the rules relating to EH handlers. There is still a known
bug: during selection, a command becomes invisible to the EH handlers
because it only appears in a pointer on the stack of a different thread.
This bug is addressed in a subsequent patch.
Signed-off-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Tested-by: default avatarOndrej Zary <linux@rainbow-software.org>
Tested-by: default avatarMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent f27db8eb
......@@ -2269,23 +2269,65 @@ static void NCR5380_dma_complete(NCR5380_instance * instance) {
}
#endif /* def REAL_DMA */
/*
* Function : int NCR5380_abort (struct scsi_cmnd *cmd)
*
* Purpose : abort a command
*
* Inputs : cmd - the scsi_cmnd to abort, code - code to set the
* host byte of the result field to, if zero DID_ABORTED is
* used.
*
* Returns : SUCCESS - success, FAILED on failure.
*
* XXX - there is no way to abort the command that is currently
* connected, you have to wait for it to complete. If this is
* a problem, we could implement longjmp() / setjmp(), setjmp()
* called where the loop started in NCR5380_main().
*
* Locks: host lock taken by caller
/**
* list_find_cmd - test for presence of a command in a linked list
* @haystack: list of commands
* @needle: command to search for
*/
static bool list_find_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
struct NCR5380_cmd *ncmd;
list_for_each_entry(ncmd, haystack, list)
if (NCR5380_to_scmd(ncmd) == needle)
return true;
return false;
}
/**
* list_remove_cmd - remove a command from linked list
* @haystack: list of commands
* @needle: command to remove
*/
static bool list_del_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
if (list_find_cmd(haystack, needle)) {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
list_del(&ncmd->list);
return true;
}
return false;
}
/**
* NCR5380_abort - scsi host eh_abort_handler() method
* @cmd: the command to be aborted
*
* Try to abort a given command by removing it from queues and/or sending
* the target an abort message. This may not succeed in causing a target
* to abort the command. Nonetheless, the low-level driver must forget about
* the command because the mid-layer reclaims it and it may be re-issued.
*
* The normal path taken by a command is as follows. For EH we trace this
* same path to locate and abort the command.
*
* unissued -> selecting -> [unissued -> selecting ->]... connected ->
* [disconnected -> connected ->]...
* [autosense -> connected ->] done
*
* If cmd is unissued then just remove it.
* If cmd is disconnected, try to select the target.
* If cmd is connected, try to send an abort message.
* If cmd is waiting for autosense, give it a chance to complete but check
* that it isn't left connected.
* If cmd was not found at all then presumably it has already been completed,
* in which case return SUCCESS to try to avoid further EH measures.
* If the command has not completed yet, we must not fail to find it.
*/
static int NCR5380_abort(struct scsi_cmnd *cmd)
......@@ -2293,18 +2335,101 @@ static int NCR5380_abort(struct scsi_cmnd *cmd)
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long flags;
int result = SUCCESS;
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
scmd_printk(KERN_INFO, cmd, "aborting command\n");
scmd_printk(KERN_INFO, cmd, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
if (list_del_cmd(&hostdata->unissued, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from issue queue\n", cmd);
cmd->result = DID_ABORT << 16;
cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
}
if (list_del_cmd(&hostdata->disconnected, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from disconnected list\n", cmd);
cmd->result = DID_ERROR << 16;
if (!hostdata->connected)
NCR5380_select(instance, cmd);
if (hostdata->connected != cmd) {
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
if (do_abort(instance)) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
if (cmd->cmnd[0] == REQUEST_SENSE)
complete_cmd(instance, cmd);
else {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
/* Perform autosense for this command */
list_add(&ncmd->list, &hostdata->autosense);
}
}
if (list_find_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: found %p on sense queue\n", cmd);
spin_unlock_irqrestore(&hostdata->lock, flags);
queue_work(hostdata->work_q, &hostdata->main_task);
msleep(1000);
spin_lock_irqsave(&hostdata->lock, flags);
if (list_del_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from sense queue\n", cmd);
set_host_byte(cmd, DID_ABORT);
complete_cmd(instance, cmd);
goto out;
}
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
if (do_abort(instance)) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
complete_cmd(instance, cmd);
}
out:
if (result == FAILED)
dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
else
dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
queue_work(hostdata->work_q, &hostdata->main_task);
spin_unlock_irqrestore(&hostdata->lock, flags);
return FAILED;
return result;
}
......
......@@ -2480,41 +2480,168 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
}
/*
* Function : int NCR5380_abort (struct scsi_cmnd *cmd)
*
* Purpose : abort a command
*
* Inputs : cmd - the scsi_cmnd to abort, code - code to set the
* host byte of the result field to, if zero DID_ABORTED is
* used.
*
* Returns : SUCCESS - success, FAILED on failure.
*
* XXX - there is no way to abort the command that is currently
* connected, you have to wait for it to complete. If this is
* a problem, we could implement longjmp() / setjmp(), setjmp()
* called where the loop started in NCR5380_main().
/**
* list_find_cmd - test for presence of a command in a linked list
* @haystack: list of commands
* @needle: command to search for
*/
static bool list_find_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
struct NCR5380_cmd *ncmd;
list_for_each_entry(ncmd, haystack, list)
if (NCR5380_to_scmd(ncmd) == needle)
return true;
return false;
}
/**
* list_remove_cmd - remove a command from linked list
* @haystack: list of commands
* @needle: command to remove
*/
static
int NCR5380_abort(struct scsi_cmnd *cmd)
static bool list_del_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
if (list_find_cmd(haystack, needle)) {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
list_del(&ncmd->list);
return true;
}
return false;
}
/**
* NCR5380_abort - scsi host eh_abort_handler() method
* @cmd: the command to be aborted
*
* Try to abort a given command by removing it from queues and/or sending
* the target an abort message. This may not succeed in causing a target
* to abort the command. Nonetheless, the low-level driver must forget about
* the command because the mid-layer reclaims it and it may be re-issued.
*
* The normal path taken by a command is as follows. For EH we trace this
* same path to locate and abort the command.
*
* unissued -> selecting -> [unissued -> selecting ->]... connected ->
* [disconnected -> connected ->]...
* [autosense -> connected ->] done
*
* If cmd is unissued then just remove it.
* If cmd is disconnected, try to select the target.
* If cmd is connected, try to send an abort message.
* If cmd is waiting for autosense, give it a chance to complete but check
* that it isn't left connected.
* If cmd was not found at all then presumably it has already been completed,
* in which case return SUCCESS to try to avoid further EH measures.
* If the command has not completed yet, we must not fail to find it.
*/
static int NCR5380_abort(struct scsi_cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long flags;
int result = SUCCESS;
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
scmd_printk(KERN_INFO, cmd, "aborting command\n");
scmd_printk(KERN_INFO, cmd, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
if (list_del_cmd(&hostdata->unissued, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from issue queue\n", cmd);
cmd->result = DID_ABORT << 16;
cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
}
if (list_del_cmd(&hostdata->disconnected, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from disconnected list\n", cmd);
cmd->result = DID_ERROR << 16;
if (!hostdata->connected)
NCR5380_select(instance, cmd);
if (hostdata->connected != cmd) {
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
if (do_abort(instance)) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
if (cmd->cmnd[0] == REQUEST_SENSE)
complete_cmd(instance, cmd);
else {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
/* Perform autosense for this command */
list_add(&ncmd->list, &hostdata->autosense);
}
}
if (list_find_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: found %p on sense queue\n", cmd);
spin_unlock_irqrestore(&hostdata->lock, flags);
queue_work(hostdata->work_q, &hostdata->main_task);
msleep(1000);
spin_lock_irqsave(&hostdata->lock, flags);
if (list_del_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from sense queue\n", cmd);
set_host_byte(cmd, DID_ABORT);
complete_cmd(instance, cmd);
goto out;
}
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
if (do_abort(instance)) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
complete_cmd(instance, cmd);
}
out:
if (result == FAILED)
dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
else
dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
queue_work(hostdata->work_q, &hostdata->main_task);
maybe_release_dma_irq(instance);
spin_unlock_irqrestore(&hostdata->lock, flags);
return FAILED;
return result;
}
......
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