5.15-stable review patch. If anyone has any objections, please let me know.
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From: Christoph Hellwig hch@lst.de
[ Upstream commit 71bada345b33b9297e7cc9415db6328c99b554f9 ]
Replace the big fat memset that requires saving and restoring various fields with just initializing those fields that need initialization.
All the clearing to 0 is moved to scsi_prepare_cmd() as scsi_ioctl_reset() alreadly uses kzalloc() to allocate a pre-zeroed command.
This is still conservative and can probably be optimized further.
Link: https://lore.kernel.org/r/20220224175552.988286-3-hch@lst.de Reviewed-by: Bart Van Assche bvanassche@acm.org Reviewed-by: John Garry john.garry@huawei.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Stable-dep-of: dce5c4afd035 ("scsi: core: Clear driver private data when retrying request") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/scsi_lib.c | 60 +++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 32 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9721984fd9bc6..ddaffaea2c32c 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1114,45 +1114,16 @@ static void scsi_cleanup_rq(struct request *rq) /* Called before a request is prepared. See also scsi_mq_prep_fn(). */ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) { - void *buf = cmd->sense_buffer; - void *prot = cmd->prot_sdb; struct request *rq = scsi_cmd_to_rq(cmd); - unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS; - unsigned long jiffies_at_alloc; - int retries, to_clear; - bool in_flight; - int budget_token = cmd->budget_token; - - if (!blk_rq_is_passthrough(rq) && !(flags & SCMD_INITIALIZED)) { - flags |= SCMD_INITIALIZED; + + if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { + cmd->flags |= SCMD_INITIALIZED; scsi_initialize_rq(rq); }
- jiffies_at_alloc = cmd->jiffies_at_alloc; - retries = cmd->retries; - in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); - /* - * Zero out the cmd, except for the embedded scsi_request. Only clear - * the driver-private command data if the LLD does not supply a - * function to initialize that data. - */ - to_clear = sizeof(*cmd) - sizeof(cmd->req); - if (!dev->host->hostt->init_cmd_priv) - to_clear += dev->host->hostt->cmd_size; - memset((char *)cmd + sizeof(cmd->req), 0, to_clear); - cmd->device = dev; - cmd->sense_buffer = buf; - cmd->prot_sdb = prot; - cmd->flags = flags; INIT_LIST_HEAD(&cmd->eh_entry); INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); - cmd->jiffies_at_alloc = jiffies_at_alloc; - cmd->retries = retries; - if (in_flight) - __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); - cmd->budget_token = budget_token; - }
static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, @@ -1539,10 +1510,35 @@ static blk_status_t scsi_prepare_cmd(struct request *req) struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); struct scsi_device *sdev = req->q->queuedata; struct Scsi_Host *shost = sdev->host; + bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); struct scatterlist *sg;
scsi_init_command(sdev, cmd);
+ cmd->eh_eflags = 0; + cmd->allowed = 0; + cmd->prot_type = 0; + cmd->prot_flags = 0; + cmd->submitter = 0; + cmd->cmd_len = 0; + cmd->cmnd = NULL; + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); + cmd->underflow = 0; + cmd->transfersize = 0; + cmd->host_scribble = NULL; + cmd->result = 0; + cmd->extra_len = 0; + cmd->state = 0; + if (in_flight) + __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); + + /* + * Only clear the driver-private command data if the LLD does not supply + * a function to initialize that data. + */ + if (!shost->hostt->init_cmd_priv) + memset(cmd + 1, 0, shost->hostt->cmd_size); + cmd->prot_op = SCSI_PROT_NORMAL; if (blk_rq_bytes(req)) cmd->sc_data_direction = rq_dma_dir(req);