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 e195f7f1fdbf4dea9eff8b252b606273431027a1..04648a08ffdf8005fe87fbddf9a9ca542c823396 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -71,7 +71,7 @@ static int discard_pdu(struct thread_data *td, struct fifo *fifo, int fd,
  * 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 @@ int is_blktrace(const char *filename)
                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 @@ static void handle_trace_notify(struct blk_io_trace *t)
 {
        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 @@ static void handle_trace(struct thread_data *td, struct blk_io_trace *t,
                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 @@ int load_blktrace(struct thread_data *td, const char *filename)
                        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 0d7fbeb9b734980e4883d5feff3dde2a6e5ba9e0..a6dcb4ea84a0b36568ad2dec471f570607437f37 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -479,8 +479,8 @@ extern void reset_all_stats(struct thread_data *);
  * 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 9bcf0d8e2982e37ce5d48fbd64e9653872e54ea0..dadbf0fa7b3f302792c3b69eeedb8e1e3f9faf94 100644 (file)
--- a/iolog.c
+++ b/iolog.c
@@ -480,12 +480,14 @@ int init_iolog(struct thread_data *td)
        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 715f2260a3f6992b13e2e6f164511b7a08e54e82..4b5903471bf8a421c0571d3d8a2de4461d74b417 100644 (file)
--- a/os/os.h
+++ b/os/os.h
@@ -220,12 +220,13 @@ static inline uint64_t fio_swap64(uint64_t val)
 })
 
 #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;
 }