[PATCH] Split struct request ->flags into two parts

Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 19 insertions, 18 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d6743b959a7..71084728eb4 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -82,7 +82,7 @@ static void scsi_unprep_request(struct request *req)
 {
         struct scsi_cmnd *cmd = req->special;
 
-        req->flags &= ~REQ_DONTPREP;
+        req->cmd_flags &= ~REQ_DONTPREP;
         req->special = NULL;
 
         scsi_put_command(cmd);
@@ -196,7 +196,8 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
         req->sense_len = 0;
         req->retries = retries;
         req->timeout = timeout;
-        req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET;
+        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT;
 
         /*
          * head injection *required* here otherwise quiesce won't work
@@ -397,7 +398,8 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
         req = blk_get_request(sdev->request_queue, write, gfp);
         if (!req)
                 goto free_sense;
-        req->flags |= REQ_BLOCK_PC | REQ_QUIET;
+        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        req->cmd_flags |= REQ_QUIET;
 
         if (use_sg)
                 err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp);
@@ -933,7 +935,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                         break;
                                 }
                         }
-                        if (!(req->flags & REQ_QUIET)) {
+                        if (!(req->cmd_flags & REQ_QUIET)) {
                                 scmd_printk(KERN_INFO, cmd,
                                             "Device not ready: ");
                                 scsi_print_sense_hdr("", &sshdr);
@@ -941,7 +943,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                         scsi_end_request(cmd, 0, this_count, 1);
                         return;
                 case VOLUME_OVERFLOW:
-                        if (!(req->flags & REQ_QUIET)) {
+                        if (!(req->cmd_flags & REQ_QUIET)) {
                                 scmd_printk(KERN_INFO, cmd,
                                             "Volume overflow, CDB: ");
                                 __scsi_print_command(cmd->cmnd);
@@ -963,7 +965,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                 return;
         }
         if (result) {
-                if (!(req->flags & REQ_QUIET)) {
+                if (!(req->cmd_flags & REQ_QUIET)) {
                         scmd_printk(KERN_INFO, cmd,
                                     "SCSI error: return code = 0x%08x\n",
                                     result);
@@ -995,7 +997,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
         /*
          * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer
          */
-        if ((req->flags & REQ_BLOCK_PC) && !req->bio) {
+        if (blk_pc_request(req) && !req->bio) {
                 cmd->request_bufflen = req->data_len;
                 cmd->request_buffer = req->data;
                 req->buffer = req->data;
@@ -1139,13 +1141,12 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
          * these two cases differently.  We differentiate by looking
          * at request->cmd, as this tells us the real story.
          */
-        if (req->flags & REQ_SPECIAL && req->special) {
+        if (blk_special_request(req) && req->special)
                 cmd = req->special;
-        } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
-
-                if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) {
-                        if(specials_only == SDEV_QUIESCE ||
-                                        specials_only == SDEV_BLOCK)
+        else if (blk_pc_request(req) || blk_fs_request(req)) {
+                if (unlikely(specials_only) && !(req->cmd_flags & REQ_PREEMPT)){
+                        if (specials_only == SDEV_QUIESCE ||
+                            specials_only == SDEV_BLOCK)
                                 goto defer;
                         
                         sdev_printk(KERN_ERR, sdev,
@@ -1153,7 +1154,6 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                         goto kill;
                 }
                         
-                        
                 /*
                  * Now try and find a command block that we can use.
                  */
@@ -1184,7 +1184,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
          * lock.  We hope REQ_STARTED prevents anything untoward from
          * happening now.
          */
-        if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
+        if (blk_fs_request(req) || blk_pc_request(req)) {
                 int ret;
 
                 /*
@@ -1216,7 +1216,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                 /*
                  * Initialize the actual SCSI command for this request.
                  */
-                if (req->flags & REQ_BLOCK_PC) {
+                if (blk_pc_request(req)) {
                         scsi_setup_blk_pc_cmnd(cmd);
                 } else if (req->rq_disk) {
                         struct scsi_driver *drv;
@@ -1233,7 +1233,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
         /*
          * The request is now prepped, no need to come back here
          */
-        req->flags |= REQ_DONTPREP;
+        req->cmd_flags |= REQ_DONTPREP;
         return BLKPREP_OK;
 
  defer:
@@ -1454,8 +1454,9 @@ static void scsi_request_fn(struct request_queue *q)
                 if (unlikely(cmd == NULL)) {
                         printk(KERN_CRIT "impossible request in %s.\n"
                                          "please mail a stack trace to "
-                                         "linux-scsi@vger.kernel.org",
+                                         "linux-scsi@vger.kernel.org\n",
                                          __FUNCTION__);
+                        blk_dump_rq_flags(req, "foo");
                         BUG();
                 }
                 spin_lock(shost->host_lock);