Differentiate between blk_io_trace and blk_io_trace2 when relaying to
user-space depending on which version has been requested by the blktrace
utility.

Signed-off-by: Johannes Thumshirn <johannes.thumsh...@wdc.com>
---
 kernel/trace/blktrace.c | 62 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 57 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 14fb4e7296cf..6dc7396c26c2 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -91,6 +91,29 @@ static void record_blktrace_event(struct blk_io_trace *t, 
pid_t pid, int cpu,
                memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
 }
 
+static void record_blktrace_event2(struct blk_io_trace2 *t2, pid_t pid, int 
cpu,
+                                  sector_t sector, int bytes, u64 what,
+                                  dev_t dev, int error, u64 cgid,
+                                  ssize_t cgid_len, void *pdu_data,
+                                  int pdu_len)
+
+{
+       t2->pid = pid;
+       t2->cpu = cpu;
+
+       t2->sector = sector;
+       t2->bytes = bytes;
+       t2->action = what;
+       t2->device = dev;
+       t2->error = error;
+       t2->pdu_len = pdu_len + cgid_len;
+
+       if (cgid_len)
+               memcpy((void *)t2 + sizeof(*t2), &cgid, cgid_len);
+       if (pdu_len)
+               memcpy((void *)t2 + sizeof(*t2) + cgid_len, pdu_data, pdu_len);
+}
+
 static void relay_blktrace_event(struct blk_trace *bt, unsigned long sequence,
                                 pid_t pid, int cpu, sector_t sector, int bytes,
                                 u32 what, int error, u64 cgid,
@@ -111,6 +134,26 @@ static void relay_blktrace_event(struct blk_trace *bt, 
unsigned long sequence,
                              cgid, cgid_len, pdu_data, pdu_len);
 }
 
+static void relay_blktrace_event2(struct blk_trace *bt, unsigned long sequence,
+                                 pid_t pid, int cpu, sector_t sector,
+                                 int bytes, u64 what, int error, u64 cgid,
+                                 ssize_t cgid_len, void *pdu_data, int pdu_len)
+{
+       struct blk_io_trace2 *t;
+       size_t trace_len = sizeof(struct blk_io_trace2) + pdu_len + cgid_len;
+
+       t = relay_reserve(bt->rchan, trace_len);
+       if (!t)
+               return;
+
+       t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE2_VERSION;
+       t->sequence = sequence;
+       t->time = ktime_to_ns(ktime_get());
+
+       record_blktrace_event2(t, pid, cpu, sector, bytes, what, bt->dev, error,
+                              cgid, cgid_len, pdu_data, pdu_len);
+}
+
 /*
  * Send out a notify message.
  */
@@ -146,8 +189,12 @@ static void trace_note(struct blk_trace *bt, pid_t pid, 
int action,
        if (!bt->rchan)
                return;
 
-       relay_blktrace_event(bt, 0, pid, cpu, 0, 0, action, 0, cgid,
-                            cgid_len, (void *)data, len);
+       if (bt->version == 1)
+               relay_blktrace_event(bt, 0, pid, cpu, 0, 0, action, 0, cgid,
+                                    cgid_len, (void *)data, len);
+       else
+               relay_blktrace_event2(bt, 0, pid, cpu, 0, 0, action, 0, cgid,
+                                     cgid_len, (void *)data, len);
 }
 
 /*
@@ -320,9 +367,14 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t 
sector, int bytes,
        local_irq_save(flags);
        sequence = per_cpu_ptr(bt->sequence, cpu);
        (*sequence)++;
-       relay_blktrace_event(bt, *sequence, pid, cpu, sector, bytes,
-                            lower_32_bits(what), error, cgid, cgid_len,
-                            pdu_data, pdu_len);
+       if (bt->version == 1)
+               relay_blktrace_event(bt, *sequence, pid, cpu, sector, bytes,
+                                    lower_32_bits(what), error, cgid,
+                                    cgid_len, pdu_data, pdu_len);
+       else
+               relay_blktrace_event2(bt, *sequence, pid, cpu, sector, bytes,
+                                     what, error, cgid, cgid_len, pdu_data,
+                                     pdu_len);
        local_irq_restore(flags);
 }
 
-- 
2.51.0


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