3.16.58-rc1 review patch. If anyone has any objections, please let me know.
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From: Jason Yan yanaijie@huawei.com
commit 318aaf34f1179b39fa9c30fa0f3288b645beee39 upstream.
When ata device doing EH, some commands still attached with tasks are not passed to libata when abort failed or recover failed, so libata did not handle these commands. After these commands done, sas task is freed, but ata qc is not freed. This will cause ata qc leak and trigger a warning like below:
WARNING: CPU: 0 PID: 28512 at drivers/ata/libata-eh.c:4037 ata_eh_finish+0xb4/0xcc CPU: 0 PID: 28512 Comm: kworker/u32:2 Tainted: G W OE 4.14.0#1 ...... Call trace: [<ffff0000088b7bd0>] ata_eh_finish+0xb4/0xcc [<ffff0000088b8420>] ata_do_eh+0xc4/0xd8 [<ffff0000088b8478>] ata_std_error_handler+0x44/0x8c [<ffff0000088b8068>] ata_scsi_port_error_handler+0x480/0x694 [<ffff000008875fc4>] async_sas_ata_eh+0x4c/0x80 [<ffff0000080f6be8>] async_run_entry_fn+0x4c/0x170 [<ffff0000080ebd70>] process_one_work+0x144/0x390 [<ffff0000080ec100>] worker_thread+0x144/0x418 [<ffff0000080f2c98>] kthread+0x10c/0x138 [<ffff0000080855dc>] ret_from_fork+0x10/0x18
If ata qc leaked too many, ata tag allocation will fail and io blocked for ever.
As suggested by Dan Williams, defer ata device commands to libata and merge sas_eh_finish_cmd() with sas_eh_defer_cmd(). libata will handle ata qcs correctly after this.
Signed-off-by: Jason Yan yanaijie@huawei.com CC: Xiaofei Tan tanxiaofei@huawei.com CC: John Garry john.garry@huawei.com CC: Dan Williams dan.j.williams@intel.com Reviewed-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/scsi/libsas/sas_scsi_host.c | 33 ++++++++++++----------------- 1 file changed, 13 insertions(+), 20 deletions(-)
--- a/drivers/scsi/libsas/sas_scsi_host.c +++ b/drivers/scsi/libsas/sas_scsi_host.c @@ -250,6 +250,7 @@ out_done: static void sas_eh_finish_cmd(struct scsi_cmnd *cmd) { struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host); + struct domain_device *dev = cmd_to_domain_dev(cmd); struct sas_task *task = TO_SAS_TASK(cmd);
/* At this point, we only get called following an actual abort @@ -258,6 +259,14 @@ static void sas_eh_finish_cmd(struct scs */ sas_end_task(cmd, task);
+ if (dev_is_sata(dev)) { + /* defer commands to libata so that libata EH can + * handle ata qcs correctly + */ + list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q); + return; + } + /* now finish the command and move it on to the error * handler done list, this also takes it off the * error handler pending list. @@ -265,22 +274,6 @@ static void sas_eh_finish_cmd(struct scs scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q); }
-static void sas_eh_defer_cmd(struct scsi_cmnd *cmd) -{ - struct domain_device *dev = cmd_to_domain_dev(cmd); - struct sas_ha_struct *ha = dev->port->ha; - struct sas_task *task = TO_SAS_TASK(cmd); - - if (!dev_is_sata(dev)) { - sas_eh_finish_cmd(cmd); - return; - } - - /* report the timeout to libata */ - sas_end_task(cmd, task); - list_move_tail(&cmd->eh_entry, &ha->eh_ata_q); -} - static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd) { struct scsi_cmnd *cmd, *n; @@ -288,7 +281,7 @@ static void sas_scsi_clear_queue_lu(stru list_for_each_entry_safe(cmd, n, error_q, eh_entry) { if (cmd->device->sdev_target == my_cmd->device->sdev_target && cmd->device->lun == my_cmd->device->lun) - sas_eh_defer_cmd(cmd); + sas_eh_finish_cmd(cmd); } }
@@ -677,12 +670,12 @@ static void sas_eh_handle_sas_errors(str case TASK_IS_DONE: SAS_DPRINTK("%s: task 0x%p is done\n", __func__, task); - sas_eh_defer_cmd(cmd); + sas_eh_finish_cmd(cmd); continue; case TASK_IS_ABORTED: SAS_DPRINTK("%s: task 0x%p is aborted\n", __func__, task); - sas_eh_defer_cmd(cmd); + sas_eh_finish_cmd(cmd); continue; case TASK_IS_AT_LU: SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task); @@ -693,7 +686,7 @@ static void sas_eh_handle_sas_errors(str "recovered\n", SAS_ADDR(task->dev), cmd->device->lun); - sas_eh_defer_cmd(cmd); + sas_eh_finish_cmd(cmd); sas_scsi_clear_queue_lu(work_q, cmd); goto Again; }