blktrace: differentiate between blk_io_trace versions

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.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 185f19c9f772d36989a91064a49a250d4eef5c73..5f8ecf88a19612bf8105aa066d9d13e5226dc32c 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -91,7 +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 relay_blktrace_event(struct blk_trace *bt, unsigned long sequence,
+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_event1(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)
@@ -111,6 +133,40 @@ 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);
+}
+
+static void relay_blktrace_event(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)
+{
+       if (bt->version == 2)
+               return relay_blktrace_event2(bt, sequence, pid, cpu, sector,
+                                            bytes, what, error, cgid, cgid_len,
+                                            pdu_data, pdu_len);
+       return relay_blktrace_event1(bt, sequence, pid, cpu, sector, bytes,
+                                    lower_32_bits(what), error, cgid, cgid_len,
+                                    pdu_data, pdu_len);
+}
+
 /*
  * Send out a notify message.
  */