blktrace: support discard requests

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 14 insertions, 1 deletions

diff --git a/block/blktrace.c b/block/blktrace.c
index eb9651ccb241..7495a84353e4 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -114,7 +114,13 @@ static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK
 /*
  * Bio action bits of interest
  */
-static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD), 0, 0, 0, BLK_TC_ACT(BLK_TC_META) };
+static u32 bio_act[17] __read_mostly = { 
+        [1] = BLK_TC_ACT(BLK_TC_BARRIER),
+        [2] = BLK_TC_ACT(BLK_TC_SYNC),
+        [4] = BLK_TC_ACT(BLK_TC_AHEAD),
+        [8] = BLK_TC_ACT(BLK_TC_META),
+        [16] = BLK_TC_ACT(BLK_TC_DISCARD)
+};
 
 /*
  * More could be added as needed, taking care to increment the decrementer
@@ -128,6 +134,8 @@ static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_AC
         (((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD))
 #define trace_meta_bit(rw)      \
         (((rw) & (1 << BIO_RW_META)) >> (BIO_RW_META - 3))
+#define trace_discard_bit(rw)   \
+        (((rw) & (1 << BIO_RW_DISCARD)) >> (BIO_RW_DISCARD - 4))
 
 /*
  * The worker for the various blk_add_trace*() types. Fills out a
@@ -151,6 +159,7 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
         what |= bio_act[trace_sync_bit(rw)];
         what |= bio_act[trace_ahead_bit(rw)];
         what |= bio_act[trace_meta_bit(rw)];
+        what |= bio_act[trace_discard_bit(rw)];
 
         pid = tsk->pid;
         if (unlikely(act_log_check(bt, what, sector, pid)))
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index d084b8d227a5..27da2cc682ee 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -21,6 +21,7 @@ enum blktrace_cat {
         BLK_TC_NOTIFY   = 1 << 10,      /* special message */
         BLK_TC_AHEAD    = 1 << 11,      /* readahead */
         BLK_TC_META     = 1 << 12,      /* metadata */
+        BLK_TC_DISCARD  = 1 << 13,      /* discard requests */
 
         BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
 };
@@ -195,6 +196,9 @@ static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
         if (likely(!bt))
                 return;
 
+        if (blk_discard_rq(rq))
+                rw |= (1 << BIO_RW_DISCARD);
+
         if (blk_pc_request(rq)) {
                 what |= BLK_TC_ACT(BLK_TC_PC);
                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);