[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, 35 insertions, 66 deletions

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 51dc0edf76e0..9b91bb70c5ed 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -382,8 +382,8 @@ unsigned blk_ordered_req_seq(struct request *rq)
         if (rq == &q->post_flush_rq)
                 return QUEUE_ORDSEQ_POSTFLUSH;
 
-        if ((rq->flags & REQ_ORDERED_COLOR) ==
-            (q->orig_bar_rq->flags & REQ_ORDERED_COLOR))
+        if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
+            (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
                 return QUEUE_ORDSEQ_DRAIN;
         else
                 return QUEUE_ORDSEQ_DONE;
@@ -446,8 +446,8 @@ static void queue_flush(request_queue_t *q, unsigned which)
                 end_io = post_flush_end_io;
         }
 
+        rq->cmd_flags = REQ_HARDBARRIER;
         rq_init(q, rq);
-        rq->flags = REQ_HARDBARRIER;
         rq->elevator_private = NULL;
         rq->rq_disk = q->bar_rq.rq_disk;
         rq->rl = NULL;
@@ -471,9 +471,11 @@ static inline struct request *start_ordered(request_queue_t *q,
         blkdev_dequeue_request(rq);
         q->orig_bar_rq = rq;
         rq = &q->bar_rq;
+        rq->cmd_flags = 0;
         rq_init(q, rq);
-        rq->flags = bio_data_dir(q->orig_bar_rq->bio);
-        rq->flags |= q->ordered & QUEUE_ORDERED_FUA ? REQ_FUA : 0;
+        if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
+                rq->cmd_flags |= REQ_RW;
+        rq->cmd_flags |= q->ordered & QUEUE_ORDERED_FUA ? REQ_FUA : 0;
         rq->elevator_private = NULL;
         rq->rl = NULL;
         init_request_from_bio(rq, q->orig_bar_rq->bio);
@@ -1124,7 +1126,7 @@ void blk_queue_end_tag(request_queue_t *q, struct request *rq)
         }
 
         list_del_init(&rq->queuelist);
-        rq->flags &= ~REQ_QUEUED;
+        rq->cmd_flags &= ~REQ_QUEUED;
         rq->tag = -1;
 
         if (unlikely(bqt->tag_index[tag] == NULL))
@@ -1160,7 +1162,7 @@ int blk_queue_start_tag(request_queue_t *q, struct request *rq)
         struct blk_queue_tag *bqt = q->queue_tags;
         int tag;
 
-        if (unlikely((rq->flags & REQ_QUEUED))) {
+        if (unlikely((rq->cmd_flags & REQ_QUEUED))) {
                 printk(KERN_ERR 
                        "%s: request %p for device [%s] already tagged %d",
                        __FUNCTION__, rq,
@@ -1174,7 +1176,7 @@ int blk_queue_start_tag(request_queue_t *q, struct request *rq)
 
         __set_bit(tag, bqt->tag_map);
 
-        rq->flags |= REQ_QUEUED;
+        rq->cmd_flags |= REQ_QUEUED;
         rq->tag = tag;
         bqt->tag_index[tag] = rq;
         blkdev_dequeue_request(rq);
@@ -1210,65 +1212,31 @@ void blk_queue_invalidate_tags(request_queue_t *q)
                         printk(KERN_ERR
                                "%s: bad tag found on list\n", __FUNCTION__);
                         list_del_init(&rq->queuelist);
-                        rq->flags &= ~REQ_QUEUED;
+                        rq->cmd_flags &= ~REQ_QUEUED;
                 } else
                         blk_queue_end_tag(q, rq);
 
-                rq->flags &= ~REQ_STARTED;
+                rq->cmd_flags &= ~REQ_STARTED;
                 __elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 0);
         }
 }
 
 EXPORT_SYMBOL(blk_queue_invalidate_tags);
 
-static const char * const rq_flags[] = {
-        "REQ_RW",
-        "REQ_FAILFAST",
-        "REQ_SORTED",
-        "REQ_SOFTBARRIER",
-        "REQ_HARDBARRIER",
-        "REQ_FUA",
-        "REQ_CMD",
-        "REQ_NOMERGE",
-        "REQ_STARTED",
-        "REQ_DONTPREP",
-        "REQ_QUEUED",
-        "REQ_ELVPRIV",
-        "REQ_PC",
-        "REQ_BLOCK_PC",
-        "REQ_SENSE",
-        "REQ_FAILED",
-        "REQ_QUIET",
-        "REQ_SPECIAL",
-        "REQ_DRIVE_CMD",
-        "REQ_DRIVE_TASK",
-        "REQ_DRIVE_TASKFILE",
-        "REQ_PREEMPT",
-        "REQ_PM_SUSPEND",
-        "REQ_PM_RESUME",
-        "REQ_PM_SHUTDOWN",
-        "REQ_ORDERED_COLOR",
-};
-
 void blk_dump_rq_flags(struct request *rq, char *msg)
 {
         int bit;
 
-        printk("%s: dev %s: flags = ", msg,
-                rq->rq_disk ? rq->rq_disk->disk_name : "?");
-        bit = 0;
-        do {
-                if (rq->flags & (1 << bit))
-                        printk("%s ", rq_flags[bit]);
-                bit++;
-        } while (bit < __REQ_NR_BITS);
+        printk("%s: dev %s: type=%x, flags=%x\n", msg,
+                rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type,
+                rq->cmd_flags);
 
         printk("\nsector %llu, nr/cnr %lu/%u\n", (unsigned long long)rq->sector,
                                                        rq->nr_sectors,
                                                        rq->current_nr_sectors);
         printk("bio %p, biotail %p, buffer %p, data %p, len %u\n", rq->bio, rq->biotail, rq->buffer, rq->data, rq->data_len);
 
-        if (rq->flags & (REQ_BLOCK_PC | REQ_PC)) {
+        if (blk_pc_request(rq)) {
                 printk("cdb: ");
                 for (bit = 0; bit < sizeof(rq->cmd); bit++)
                         printk("%02x ", rq->cmd[bit]);
@@ -1441,7 +1409,7 @@ static inline int ll_new_mergeable(request_queue_t *q,
         int nr_phys_segs = bio_phys_segments(q, bio);
 
         if (req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
-                req->flags |= REQ_NOMERGE;
+                req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
                 return 0;
@@ -1464,7 +1432,7 @@ static inline int ll_new_hw_segment(request_queue_t *q,
 
         if (req->nr_hw_segments + nr_hw_segs > q->max_hw_segments
             || req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
-                req->flags |= REQ_NOMERGE;
+                req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
                 return 0;
@@ -1491,7 +1459,7 @@ static int ll_back_merge_fn(request_queue_t *q, struct request *req,
                 max_sectors = q->max_sectors;
 
         if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
-                req->flags |= REQ_NOMERGE;
+                req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
                 return 0;
@@ -1530,7 +1498,7 @@ static int ll_front_merge_fn(request_queue_t *q, struct request *req,
 
 
         if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
-                req->flags |= REQ_NOMERGE;
+                req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
                 return 0;
@@ -2029,7 +1997,7 @@ EXPORT_SYMBOL(blk_get_queue);
 
 static inline void blk_free_request(request_queue_t *q, struct request *rq)
 {
-        if (rq->flags & REQ_ELVPRIV)
+        if (rq->cmd_flags & REQ_ELVPRIV)
                 elv_put_request(q, rq);
         mempool_free(rq, q->rq.rq_pool);
 }
@@ -2044,17 +2012,17 @@ blk_alloc_request(request_queue_t *q, int rw, struct bio *bio,
                 return NULL;
 
         /*
-         * first three bits are identical in rq->flags and bio->bi_rw,
+         * first three bits are identical in rq->cmd_flags and bio->bi_rw,
          * see bio.h and blkdev.h
          */
-        rq->flags = rw;
+        rq->cmd_flags = rw;
 
         if (priv) {
                 if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) {
                         mempool_free(rq, q->rq.rq_pool);
                         return NULL;
                 }
-                rq->flags |= REQ_ELVPRIV;
+                rq->cmd_flags |= REQ_ELVPRIV;
         }
 
         return rq;
@@ -2351,7 +2319,8 @@ void blk_insert_request(request_queue_t *q, struct request *rq,
          * must not attempt merges on this) and that it acts as a soft
          * barrier
          */
-        rq->flags |= REQ_SPECIAL | REQ_SOFTBARRIER;
+        rq->cmd_type = REQ_TYPE_SPECIAL;
+        rq->cmd_flags |= REQ_SOFTBARRIER;
 
         rq->special = data;
 
@@ -2558,7 +2527,7 @@ void blk_execute_rq_nowait(request_queue_t *q, struct gendisk *bd_disk,
         int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
 
         rq->rq_disk = bd_disk;
-        rq->flags |= REQ_NOMERGE;
+        rq->cmd_flags |= REQ_NOMERGE;
         rq->end_io = done;
         WARN_ON(irqs_disabled());
         spin_lock_irq(q->queue_lock);
@@ -2728,7 +2697,7 @@ void __blk_put_request(request_queue_t *q, struct request *req)
          */
         if (rl) {
                 int rw = rq_data_dir(req);
-                int priv = req->flags & REQ_ELVPRIV;
+                int priv = req->cmd_flags & REQ_ELVPRIV;
 
                 BUG_ON(!list_empty(&req->queuelist));
 
@@ -2890,22 +2859,22 @@ static inline int attempt_front_merge(request_queue_t *q, struct request *rq)
 
 static void init_request_from_bio(struct request *req, struct bio *bio)
 {
-        req->flags |= REQ_CMD;
+        req->cmd_type = REQ_TYPE_FS;
 
         /*
          * inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
          */
         if (bio_rw_ahead(bio) || bio_failfast(bio))
-                req->flags |= REQ_FAILFAST;
+                req->cmd_flags |= REQ_FAILFAST;
 
         /*
          * REQ_BARRIER implies no merging, but lets make it explicit
          */
         if (unlikely(bio_barrier(bio)))
-                req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+                req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
 
         if (bio_sync(bio))
-                req->flags |= REQ_RW_SYNC;
+                req->cmd_flags |= REQ_RW_SYNC;
 
         req->errors = 0;
         req->hard_sector = req->sector = bio->bi_sector;
@@ -3306,7 +3275,7 @@ static int __end_that_request_first(struct request *req, int uptodate,
                 req->errors = 0;
 
         if (!uptodate) {
-                if (blk_fs_request(req) && !(req->flags & REQ_QUIET))
+                if (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))
                         printk("end_request: I/O error, dev %s, sector %llu\n",
                                 req->rq_disk ? req->rq_disk->disk_name : "?",
                                 (unsigned long long)req->sector);
@@ -3569,8 +3538,8 @@ EXPORT_SYMBOL(end_request);
 
 void blk_rq_bio_prep(request_queue_t *q, struct request *rq, struct bio *bio)
 {
-        /* first two bits are identical in rq->flags and bio->bi_rw */
-        rq->flags |= (bio->bi_rw & 3);
+        /* first two bits are identical in rq->cmd_flags and bio->bi_rw */
+        rq->cmd_flags |= (bio->bi_rw & 3);
 
         rq->nr_phys_segments = bio_phys_segments(q, bio);
         rq->nr_hw_segments = bio_hw_segments(q, bio);