[PATCH] blk: cleanup generic tag support error messages

Add KERN_ERR and __FUNCTION__ to generic tag error messages, and add a comment
in blk_queue_end_tag() which explains the silent failure path.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 5 deletions

diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index 99afeec1031f..c581f9138c47 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -912,10 +912,15 @@ void blk_queue_end_tag(request_queue_t *q, struct request *rq)
         BUG_ON(tag == -1);
 
         if (unlikely(tag >= bqt->max_depth))
+                /*
+                 * This can happen after tag depth has been reduced.
+                 * FIXME: how about a warning or info message here?
+                 */
                 return;
 
         if (unlikely(!__test_and_clear_bit(tag, bqt->tag_map))) {
-                printk("attempt to clear non-busy tag (%d)\n", tag);
+                printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
+                       __FUNCTION__, tag);
                 return;
         }
 
@@ -924,7 +929,8 @@ void blk_queue_end_tag(request_queue_t *q, struct request *rq)
         rq->tag = -1;
 
         if (unlikely(bqt->tag_index[tag] == NULL))
-                printk("tag %d is missing\n", tag);
+                printk(KERN_ERR "%s: tag %d is missing\n",
+                       __FUNCTION__, tag);
 
         bqt->tag_index[tag] = NULL;
         bqt->busy--;
@@ -957,8 +963,9 @@ int blk_queue_start_tag(request_queue_t *q, struct request *rq)
 
         if (unlikely((rq->flags & REQ_QUEUED))) {
                 printk(KERN_ERR 
-                       "request %p for device [%s] already tagged %d",
-                       rq, rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
+                       "%s: request %p for device [%s] already tagged %d",
+                       __FUNCTION__, rq,
+                       rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
                 BUG();
         }
 
@@ -1001,7 +1008,8 @@ void blk_queue_invalidate_tags(request_queue_t *q)
                 rq = list_entry_rq(tmp);
 
                 if (rq->tag == -1) {
-                        printk("bad tag found on list\n");
+                        printk(KERN_ERR
+                               "%s: bad tag found on list\n", __FUNCTION__);
                         list_del_init(&rq->queuelist);
                         rq->flags &= ~REQ_QUEUED;
                 } else