blktrace: add FLUSH/FUA support

Add FLUSH/FUA support to blktrace. As FLUSH precedes WRITE and/or
FUA follows WRITE, use the same 'F' flag for both cases and
distinguish them by their (relative) position. The end results
look like (other flags might be shown also):

 - WRITE:            W
 - WRITE_FLUSH:      FW
 - WRITE_FUA:        WF
 - WRITE_FLUSH_FUA:  FWF

Note that we reuse TC_BARRIER due to lack of bit space of act_mask
so that the older versions of blktrace tools will report flush
requests as barriers from now on.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 8c7c2de..8e9e4bc 100644 (file)
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -14,7 +14,7 @@
 enum blktrace_cat {
        BLK_TC_READ     = 1 << 0,       /* reads */
        BLK_TC_WRITE    = 1 << 1,       /* writes */
-       BLK_TC_BARRIER  = 1 << 2,       /* barrier */
+       BLK_TC_FLUSH    = 1 << 2,       /* flush */
        BLK_TC_SYNC     = 1 << 3,       /* sync IO */
        BLK_TC_SYNCIO   = BLK_TC_SYNC,
        BLK_TC_QUEUE    = 1 << 4,       /* queueing/merging */
@@ -28,8 +28,9 @@ enum blktrace_cat {
        BLK_TC_META     = 1 << 12,      /* metadata */
        BLK_TC_DISCARD  = 1 << 13,      /* discard requests */
        BLK_TC_DRV_DATA = 1 << 14,      /* binary per-driver data */
+       BLK_TC_FUA      = 1 << 15,      /* fua requests */
 
-       BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
+       BLK_TC_END      = 1 << 15,      /* we've run out of bits! */
 };
 
 #define BLK_TC_SHIFT           (16)

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index bf36654..05c5e61 100644 (file)
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -8,6 +8,8 @@
 #include <linux/blkdev.h>
 #include <linux/tracepoint.h>
 
+#define RWBS_LEN       8
+
 DECLARE_EVENT_CLASS(block_rq_with_error,
 
        TP_PROTO(struct request_queue *q, struct request *rq),
@@ -19,7 +21,7 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
                __field(  sector_t,     sector                  )
                __field(  unsigned int, nr_sector               )
                __field(  int,          errors                  )
-               __array(  char,         rwbs,   6               )
+               __array(  char,         rwbs,   RWBS_LEN        )
                __dynamic_array( char,  cmd,    blk_cmd_buf_len(rq)     )
        ),
 
@@ -104,7 +106,7 @@ DECLARE_EVENT_CLASS(block_rq,
                __field(  sector_t,     sector                  )
                __field(  unsigned int, nr_sector               )
                __field(  unsigned int, bytes                   )
-               __array(  char,         rwbs,   6               )
+               __array(  char,         rwbs,   RWBS_LEN        )
                __array(  char,         comm,   TASK_COMM_LEN   )
                __dynamic_array( char,  cmd,    blk_cmd_buf_len(rq)     )
        ),
@@ -183,7 +185,7 @@ TRACE_EVENT(block_bio_bounce,
                __field( dev_t,         dev                     )
                __field( sector_t,      sector                  )
                __field( unsigned int,  nr_sector               )
-               __array( char,          rwbs,   6               )
+               __array( char,          rwbs,   RWBS_LEN        )
                __array( char,          comm,   TASK_COMM_LEN   )
        ),
 
@@ -222,7 +224,7 @@ TRACE_EVENT(block_bio_complete,
                __field( sector_t,      sector          )
                __field( unsigned,      nr_sector       )
                __field( int,           error           )
-               __array( char,          rwbs,   6       )
+               __array( char,          rwbs,   RWBS_LEN)
        ),
 
        TP_fast_assign(
@@ -249,7 +251,7 @@ DECLARE_EVENT_CLASS(block_bio,
                __field( dev_t,         dev                     )
                __field( sector_t,      sector                  )
                __field( unsigned int,  nr_sector               )
-               __array( char,          rwbs,   6               )
+               __array( char,          rwbs,   RWBS_LEN        )
                __array( char,          comm,   TASK_COMM_LEN   )
        ),
 
@@ -321,7 +323,7 @@ DECLARE_EVENT_CLASS(block_get_rq,
                __field( dev_t,         dev                     )
                __field( sector_t,      sector                  )
                __field( unsigned int,  nr_sector               )
-               __array( char,          rwbs,   6               )
+               __array( char,          rwbs,   RWBS_LEN        )
                __array( char,          comm,   TASK_COMM_LEN   )
         ),
 
@@ -456,7 +458,7 @@ TRACE_EVENT(block_split,
                __field( dev_t,         dev                             )
                __field( sector_t,      sector                          )
                __field( sector_t,      new_sector                      )
-               __array( char,          rwbs,           6               )
+               __array( char,          rwbs,           RWBS_LEN        )
                __array( char,          comm,           TASK_COMM_LEN   )
        ),
 
@@ -498,7 +500,7 @@ TRACE_EVENT(block_bio_remap,
                __field( unsigned int,  nr_sector       )
                __field( dev_t,         old_dev         )
                __field( sector_t,      old_sector      )
-               __array( char,          rwbs,   6       )
+               __array( char,          rwbs,   RWBS_LEN)
        ),
 
        TP_fast_assign(
@@ -542,7 +544,7 @@ TRACE_EVENT(block_rq_remap,
                __field( unsigned int,  nr_sector       )
                __field( dev_t,         old_dev         )
                __field( sector_t,      old_sector      )
-               __array( char,          rwbs,   6       )
+               __array( char,          rwbs,   RWBS_LEN)
        ),
 
        TP_fast_assign(

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 6957aa2..7c910a5 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -206,6 +206,8 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
        what |= MASK_TC_BIT(rw, RAHEAD);
        what |= MASK_TC_BIT(rw, META);
        what |= MASK_TC_BIT(rw, DISCARD);
+       what |= MASK_TC_BIT(rw, FLUSH);
+       what |= MASK_TC_BIT(rw, FUA);
 
        pid = tsk->pid;
        if (act_log_check(bt, what, sector, pid))
@@ -1054,6 +1056,9 @@ static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
                goto out;
        }
 
+       if (tc & BLK_TC_FLUSH)
+               rwbs[i++] = 'F';
+
        if (tc & BLK_TC_DISCARD)
                rwbs[i++] = 'D';
        else if (tc & BLK_TC_WRITE)
@@ -1063,10 +1068,10 @@ static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
        else
                rwbs[i++] = 'N';
 
+       if (tc & BLK_TC_FUA)
+               rwbs[i++] = 'F';
        if (tc & BLK_TC_AHEAD)
                rwbs[i++] = 'A';
-       if (tc & BLK_TC_BARRIER)
-               rwbs[i++] = 'B';
        if (tc & BLK_TC_SYNC)
                rwbs[i++] = 'S';
        if (tc & BLK_TC_META)
@@ -1132,7 +1137,7 @@ typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
 
 static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
 {
-       char rwbs[6];
+       char rwbs[RWBS_LEN];
        unsigned long long ts  = iter->ts;
        unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
        unsigned secs          = (unsigned long)ts;
@@ -1148,7 +1153,7 @@ static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
 
 static int blk_log_action(struct trace_iterator *iter, const char *act)
 {
-       char rwbs[6];
+       char rwbs[RWBS_LEN];
        const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
 
        fill_rwbs(rwbs, t);
@@ -1561,7 +1566,7 @@ static const struct {
 } mask_maps[] = {
        { BLK_TC_READ,          "read"          },
        { BLK_TC_WRITE,         "write"         },
-       { BLK_TC_BARRIER,       "barrier"       },
+       { BLK_TC_FLUSH,         "flush"         },
        { BLK_TC_SYNC,          "sync"          },
        { BLK_TC_QUEUE,         "queue"         },
        { BLK_TC_REQUEUE,       "requeue"       },
@@ -1573,6 +1578,7 @@ static const struct {
        { BLK_TC_META,          "meta"          },
        { BLK_TC_DISCARD,       "discard"       },
        { BLK_TC_DRV_DATA,      "drv_data"      },
+       { BLK_TC_FUA,           "fua"           },
 };
 
 static int blk_trace_str2mask(const char *str)
@@ -1788,6 +1794,9 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
 {
        int i = 0;
 
+       if (rw & REQ_FLUSH)
+               rwbs[i++] = 'F';
+
        if (rw & WRITE)
                rwbs[i++] = 'W';
        else if (rw & REQ_DISCARD)
@@ -1797,6 +1806,8 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
        else
                rwbs[i++] = 'N';
 
+       if (rw & REQ_FUA)
+               rwbs[i++] = 'F';
        if (rw & REQ_RAHEAD)
                rwbs[i++] = 'A';
        if (rw & REQ_SYNC)