blktrace: Add blktrace ioctls to SCSI generic devices

Since the SCSI layer uses the request queues from the block layer, blktrace can
also be used to trace the requests to all SCSI devices (like SCSI tape drives),
not only disks. The only missing part is the ioctl interface to start and stop
tracing.

This patch adds the SETUP, START, STOP and TEARDOWN ioctls from blktrace to the
sg device files. With this change, blktrace can be used for SCSI devices like
for disks, e.g.: blktrace -d /dev/sg1 -o - | blkparse -i -

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 7e11d23ac36a..06dadba349ac 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -148,7 +148,7 @@ extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 extern void blk_trace_shutdown(struct request_queue *);
 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 extern int do_blk_trace_setup(struct request_queue *q,
-        struct block_device *bdev, struct blk_user_trace_setup *buts);
+        char *name, dev_t dev, struct blk_user_trace_setup *buts);
 
 
 /**
@@ -282,6 +282,11 @@ static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 }
 
+extern int blk_trace_setup(request_queue_t *q, char *name, dev_t dev,
+                           char __user *arg);
+extern int blk_trace_startstop(request_queue_t *q, int start);
+extern int blk_trace_remove(request_queue_t *q);
+
 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 #define blk_trace_shutdown(q)                   do { } while (0)
@@ -290,7 +295,10 @@ static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
-#define do_blk_trace_setup(q, bdev, buts)       (-ENOTTY)
+#define do_blk_trace_setup(q, name, dev, buts)  (-ENOTTY)
+#define blk_trace_setup(q, name, dev, arg)      (-ENOTTY)
+#define blk_trace_startstop(q, start)           (-ENOTTY)
+#define blk_trace_remove(q)                     (-ENOTTY)
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 #endif /* __KERNEL__ */
 #endif