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[PATCH] sbp2: fix deadlocks and delays on device removal/rmmod 

Fixes for deadlocks of the ieee1394 and scsi subsystems and long delays in
futile error recovery attempts when SBP-2 devices are removed or drivers are
unloaded.

 - Complete commands quickly with DID_NO_CONNECT if the 1394 node is gone or if
   the 1394 low-level driver was unloaded.
 - Skip unnecessary work in the eh_abort_handler and eh_device_reset_handler if
   the node or 1394 low-level driver is gone.
 - Let scsi's high-level shut down gracefully when sbp2 is being unloaded or
   detached from the 1394 unit. A call to scsi_remove_device is added for this
   purpose, which requires us to store a scsi_device pointer.
 - scsi_device pointer is obtained from slave_alloc hook and cleared by
   slave_destroy. This avoids usage of the pointer after the scsi device was
   deleted e.g. by the user via scsi_mod's sysfs interface.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@steamballoon.com>
Cc: Ben Collins <bcollins@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jody McIntyre 2005-09-30 11:59:06 -07:00 committed by Linus Torvalds
parent 105d7b38b0
commit abd559b105
1 changed files with 58 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
drivers/ieee1394/sbp2.c
View File

@ -596,6 +596,14 @@ static void sbp2util_mark_command_completed(struct scsi_id_instance_data *scsi_i
spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
}
/*
* Is scsi_id valid? Is the 1394 node still present?
*/
static inline int sbp2util_node_is_available(struct scsi_id_instance_data *scsi_id)
{
return scsi_id && scsi_id->ne && !scsi_id->ne->in_limbo;
}
/*********************************************
@ -631,11 +639,23 @@ static int sbp2_remove(struct device *dev)
{
struct unit_directory *ud;
struct scsi_id_instance_data *scsi_id;
struct scsi_device *sdev;
SBP2_DEBUG("sbp2_remove");
ud = container_of(dev, struct unit_directory, device);
scsi_id = ud->device.driver_data;
if (!scsi_id)
return 0;
/* Trigger shutdown functions in scsi's highlevel. */
if (scsi_id->scsi_host)
scsi_unblock_requests(scsi_id->scsi_host);
sdev = scsi_id->sdev;
if (sdev) {
scsi_id->sdev = NULL;
scsi_remove_device(sdev);
}
sbp2_logout_device(scsi_id);
sbp2_remove_device(scsi_id);
@ -2473,37 +2493,26 @@ static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
struct scsi_id_instance_data *scsi_id =
(struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
struct sbp2scsi_host_info *hi;
int result = DID_NO_CONNECT << 16;
SBP2_DEBUG("sbp2scsi_queuecommand");
/*
* If scsi_id is null, it means there is no device in this slot,
* so we should return selection timeout.
*/
if (!scsi_id) {
SCpnt->result = DID_NO_CONNECT << 16;
done (SCpnt);
return 0;
}
if (!sbp2util_node_is_available(scsi_id))
goto done;
hi = scsi_id->hi;
if (!hi) {
SBP2_ERR("sbp2scsi_host_info is NULL - this is bad!");
SCpnt->result = DID_NO_CONNECT << 16;
done (SCpnt);
return(0);
goto done;
}
/*
* Until we handle multiple luns, just return selection time-out
* to any IO directed at non-zero LUNs
*/
if (SCpnt->device->lun) {
SCpnt->result = DID_NO_CONNECT << 16;
done (SCpnt);
return(0);
}
if (SCpnt->device->lun)
goto done;
/*
* Check for request sense command, and handle it here
@ -2514,7 +2523,7 @@ static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
memcpy(SCpnt->request_buffer, SCpnt->sense_buffer, SCpnt->request_bufflen);
memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer));
sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_GOOD, SCpnt, done);
return(0);
return 0;
}
/*
@ -2522,9 +2531,8 @@ static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
*/
if (!hpsb_node_entry_valid(scsi_id->ne)) {
SBP2_ERR("Bus reset in progress - rejecting command");
SCpnt->result = DID_BUS_BUSY << 16;
done (SCpnt);
return(0);
result = DID_BUS_BUSY << 16;
goto done;
}
/*
@ -2535,8 +2543,12 @@ static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_SELECTION_TIMEOUT,
SCpnt, done);
}
return 0;
return(0);
done:
SCpnt->result = result;
done(SCpnt);
return 0;
}
/*
@ -2683,14 +2695,27 @@ static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id,
}
static int sbp2scsi_slave_configure (struct scsi_device *sdev)
static int sbp2scsi_slave_alloc(struct scsi_device *sdev)
{
((struct scsi_id_instance_data *)sdev->host->hostdata[0])->sdev = sdev;
return 0;
}
static int sbp2scsi_slave_configure(struct scsi_device *sdev)
{
blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
return 0;
}
static void sbp2scsi_slave_destroy(struct scsi_device *sdev)
{
((struct scsi_id_instance_data *)sdev->host->hostdata[0])->sdev = NULL;
return;
}
/*
* Called by scsi stack when something has really gone wrong. Usually
* called when a command has timed-out for some reason.
@ -2705,7 +2730,7 @@ static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
SBP2_ERR("aborting sbp2 command");
scsi_print_command(SCpnt);
if (scsi_id) {
if (sbp2util_node_is_available(scsi_id)) {
/*
* Right now, just return any matching command structures
@ -2742,31 +2767,24 @@ static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
/*
* Called by scsi stack when something has really gone wrong.
*/
static int __sbp2scsi_reset(struct scsi_cmnd *SCpnt)
static int sbp2scsi_reset(struct scsi_cmnd *SCpnt)
{
struct scsi_id_instance_data *scsi_id =
(struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
unsigned long flags;
SBP2_ERR("reset requested");
if (scsi_id) {
spin_lock_irqsave(SCpnt->device->host->host_lock, flags);
if (sbp2util_node_is_available(scsi_id)) {
SBP2_ERR("Generating sbp2 fetch agent reset");
sbp2_agent_reset(scsi_id, 0);
}
return(SUCCESS);
}
static int sbp2scsi_reset(struct scsi_cmnd *SCpnt)
{
unsigned long flags;
int rc;
spin_lock_irqsave(SCpnt->device->host->host_lock, flags);
rc = __sbp2scsi_reset(SCpnt);
spin_unlock_irqrestore(SCpnt->device->host->host_lock, flags);
return rc;
return SUCCESS;
}
static const char *sbp2scsi_info (struct Scsi_Host *host)
@ -2817,7 +2835,9 @@ static struct scsi_host_template scsi_driver_template = {
.eh_device_reset_handler = sbp2scsi_reset,
.eh_bus_reset_handler = sbp2scsi_reset,
.eh_host_reset_handler = sbp2scsi_reset,
.slave_alloc = sbp2scsi_slave_alloc,
.slave_configure = sbp2scsi_slave_configure,
.slave_destroy = sbp2scsi_slave_destroy,
.this_id = -1,
.sg_tablesize = SG_ALL,
.use_clustering = ENABLE_CLUSTERING,