blktrace: add support for non-native endian format
The blktrace format is stored in the native endianness of
the machine it is run on. So to reply traces on a machine
with a different endianness, we need to swap the trace
fields. Detect and do this automatically.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/blktrace.c b/blktrace.c
index e195f7f..04648a0 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -71,7 +71,7 @@
* Check if this is a blktrace binary data file. We read a single trace
* into memory and check for the magic signature.
*/
-int is_blktrace(const char *filename)
+int is_blktrace(const char *filename, int *need_swap)
{
struct blk_io_trace t;
int fd, ret;
@@ -91,8 +91,19 @@
return 0;
}
- if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC)
+ if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+ *need_swap = 0;
return 1;
+ }
+
+ /*
+ * Maybe it needs to be endian swapped...
+ */
+ t.magic = fio_swap32(t.magic);
+ if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+ *need_swap = 1;
+ return 1;
+ }
return 0;
}
@@ -245,10 +256,12 @@
{
switch (t->action) {
case BLK_TN_PROCESS:
- printf("got process notify: %x, %d\n", t->action, t->pid);
+ log_info("blktrace: got process notify: %x, %d\n",
+ t->action, t->pid);
break;
case BLK_TN_TIMESTAMP:
- printf("got timestamp notify: %x, %d\n", t->action, t->pid);
+ log_info("blktrace: got timestamp notify: %x, %d\n",
+ t->action, t->pid);
break;
case BLK_TN_MESSAGE:
break;
@@ -328,11 +341,26 @@
handle_trace_fs(td, t, ttime, ios, bs);
}
+static void byteswap_trace(struct blk_io_trace *t)
+{
+ t->magic = fio_swap32(t->magic);
+ t->sequence = fio_swap32(t->sequence);
+ t->time = fio_swap64(t->time);
+ t->sector = fio_swap64(t->sector);
+ t->bytes = fio_swap32(t->bytes);
+ t->action = fio_swap32(t->action);
+ t->pid = fio_swap32(t->pid);
+ t->device = fio_swap32(t->device);
+ t->cpu = fio_swap32(t->cpu);
+ t->error = fio_swap16(t->error);
+ t->pdu_len = fio_swap16(t->pdu_len);
+}
+
/*
* Load a blktrace file by reading all the blk_io_trace entries, and storing
* them as io_pieces like the fio text version would do.
*/
-int load_blktrace(struct thread_data *td, const char *filename)
+int load_blktrace(struct thread_data *td, const char *filename, int need_swap)
{
unsigned long long ttime, delay;
struct blk_io_trace t;
@@ -370,6 +398,9 @@
break;
}
+ if (need_swap)
+ byteswap_trace(&t);
+
if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
log_err("fio: bad magic in blktrace data: %x\n",
t.magic);
diff --git a/fio.h b/fio.h
index 0d7fbeb..a6dcb4e 100644
--- a/fio.h
+++ b/fio.h
@@ -479,8 +479,8 @@
* blktrace support
*/
#ifdef FIO_HAVE_BLKTRACE
-extern int is_blktrace(const char *);
-extern int load_blktrace(struct thread_data *, const char *);
+extern int is_blktrace(const char *, int *);
+extern int load_blktrace(struct thread_data *, const char *, int);
#endif
#define for_each_td(td, i) \
diff --git a/iolog.c b/iolog.c
index 9bcf0d8..dadbf0f 100644
--- a/iolog.c
+++ b/iolog.c
@@ -480,12 +480,14 @@
int ret = 0;
if (td->o.read_iolog_file) {
+ int need_swap;
+
/*
* Check if it's a blktrace file and load that if possible.
* Otherwise assume it's a normal log file and load that.
*/
- if (is_blktrace(td->o.read_iolog_file))
- ret = load_blktrace(td, td->o.read_iolog_file);
+ if (is_blktrace(td->o.read_iolog_file, &need_swap))
+ ret = load_blktrace(td, td->o.read_iolog_file, need_swap);
else
ret = init_iolog_read(td);
} else if (td->o.write_iolog_file)
diff --git a/os/os.h b/os/os.h
index 715f226..4b59034 100644
--- a/os/os.h
+++ b/os/os.h
@@ -220,12 +220,13 @@
})
#ifndef FIO_HAVE_BLKTRACE
-static inline int is_blktrace(const char *fname)
+static inline int is_blktrace(const char *fname, int *need_swap)
{
return 0;
}
struct thread_data;
-static inline int load_blktrace(struct thread_data *td, const char *fname)
+static inline int load_blktrace(struct thread_data *td, const char *fname,
+ int need_swap)
{
return 1;
}