Requests are unprepared and reprepared when being requeued. Avoid that requeuing resets .jiffies_at_alloc and .retries by initializing these two member variables from inside blk_get_request() and by preserving both member variables when preparing a request. This patch affects the requeuing behavior of scsi-sq and scsi-mq.
Reported-by: Brian King <brk...@linux.vnet.ibm.com> References: https://lkml.org/lkml/2017/8/18/923 ("Re: [BUG][bisected 270065e] linux-next fails to boot on powerpc") Signed-off-by: Bart Van Assche <bart.vanass...@wdc.com> Cc: Brian King <brk...@linux.vnet.ibm.com> Cc: Hannes Reinecke <h...@suse.com> Cc: Christoph Hellwig <h...@lst.de> Cc: Johannes Thumshirn <jthumsh...@suse.de> --- drivers/scsi/scsi_lib.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index ebc5c713ee37..8d1ec1e7b0e2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1122,6 +1122,8 @@ void scsi_initialize_rq(struct request *rq) struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); scsi_req_init(&cmd->req); + cmd->jiffies_at_alloc = jiffies; + cmd->retries = 0; } EXPORT_SYMBOL(scsi_initialize_rq); @@ -1160,6 +1162,8 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) void *buf = cmd->sense_buffer; void *prot = cmd->prot_sdb; unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA; + unsigned long jiffies_at_alloc = cmd->jiffies_at_alloc; + int retries = cmd->retries; /* zero out the cmd, except for the embedded scsi_request */ memset((char *)cmd + sizeof(cmd->req), 0, @@ -1170,7 +1174,8 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) cmd->prot_sdb = prot; cmd->flags = unchecked_isa_dma; INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); - cmd->jiffies_at_alloc = jiffies; + cmd->jiffies_at_alloc = jiffies_at_alloc; + cmd->retries = retries; scsi_add_cmd_to_list(cmd); } -- 2.14.0
