scsi: Call scsi_initialize_rq() for filesystem requests

If a pass-through request is submitted then blk_get_request()
initializes that request by calling scsi_initialize_rq(). Also call this
function for filesystem requests. Introduce CMD_INITIALIZED to keep
track of whether or not a request has already been initialized.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 25 insertions, 4 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 938a7e398cd4..4bfe0df35823 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -642,6 +642,11 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
         if (blk_queue_add_random(q))
                 add_disk_randomness(req->rq_disk);
 
+        if (!blk_rq_is_scsi(req)) {
+                WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
+                cmd->flags &= ~SCMD_INITIALIZED;
+        }
+
         if (req->mq_ctx) {
                 /*
                  * In the MQ case the command gets freed by __blk_mq_end_request,
@@ -1110,7 +1115,8 @@ EXPORT_SYMBOL(scsi_init_io);
  * scsi_initialize_rq - initialize struct scsi_cmnd.req
  * @rq: Request associated with the SCSI command to be initialized.
  *
- * Called from inside blk_get_request().
+ * Called from inside blk_get_request() for pass-through requests and from
+ * inside scsi_init_command() for filesystem requests.
  */
 void scsi_initialize_rq(struct request *rq)
 {
@@ -1154,7 +1160,13 @@ 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;
+        struct request *rq = blk_mq_rq_from_pdu(cmd);
+        unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS;
+
+        if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) {
+                flags |= SCMD_INITIALIZED;
+                scsi_initialize_rq(rq);
+        }
 
         /* zero out the cmd, except for the embedded scsi_request */
         memset((char *)cmd + sizeof(cmd->req), 0,
@@ -1163,7 +1175,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
         cmd->device = dev;
         cmd->sense_buffer = buf;
         cmd->prot_sdb = prot;
-        cmd->flags = unchecked_isa_dma;
+        cmd->flags = flags;
         INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
         cmd->jiffies_at_alloc = jiffies;
 
@@ -1350,6 +1362,8 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
 
         ret = scsi_setup_cmnd(sdev, req);
 out:
+        if (ret != BLKPREP_OK)
+                cmd->flags &= ~SCMD_INITIALIZED;
         return scsi_prep_return(q, req, ret);
 }
 
@@ -1869,6 +1883,7 @@ static int scsi_mq_prep_fn(struct request *req)
         struct scsi_device *sdev = req->q->queuedata;
         struct Scsi_Host *shost = sdev->host;
         struct scatterlist *sg;
+        int ret;
 
         scsi_init_command(sdev, cmd);
 
@@ -1902,7 +1917,10 @@ static int scsi_mq_prep_fn(struct request *req)
 
         blk_mq_start_request(req);
 
-        return scsi_setup_cmnd(sdev, req);
+        ret = scsi_setup_cmnd(sdev, req);
+        if (ret != BLK_STS_OK)
+                cmd->flags &= ~SCMD_INITIALIZED;
+        return ret;
 }
 
 static void scsi_mq_done(struct scsi_cmnd *cmd)
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index f5afcff8d76f..a9f8f7e79d83 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -57,6 +57,9 @@ struct scsi_pointer {
 /* for scmd->flags */
 #define SCMD_TAGGED             (1 << 0)
 #define SCMD_UNCHECKED_ISA_DMA  (1 << 1)
+#define SCMD_INITIALIZED        (1 << 3)
+/* flags preserved across unprep / reprep */
+#define SCMD_PRESERVED_FLAGS    (SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
 
 struct scsi_cmnd {
         struct scsi_request req;