From: Jody McIntyre Date: Fri, 30 Sep 2005 18:59:06 +0000 (-0700) Subject: [PATCH] sbp2: fix deadlocks and delays on device removal/rmmod X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=abd559b1052e28d8b9c28aabde241f18fa89090b;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git [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 Signed-off-by: Jody McIntyre Cc: Ben Collins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c index de88218ef7cc..5d86b03979ec 100644 --- a/drivers/ieee1394/sbp2.c +++ b/drivers/ieee1394/sbp2.c @@ -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) { - blk_queue_dma_alignment(sdev->request_queue, (512 - 1)); + ((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,