tbio/ltp_tbio.c: Change the order of calling blk_cleanup_queue() and del_gendisk()

Removing ltp_tbio.ko module always reproduced a warning and panic on the old kernels that have backported kernel commit a063057d7c73 (e.g. RHEL7.6).

Removing ltp_tbio.ko module calls blk_cleanup_queue() and del_gendisk() in the order so that it triggers races or warnings since commit a063057d7c73 in kernel, and some kernel modules have fixed the issue, as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57678e5a3d5145e5f08aa1d307ba219b27b1765a
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0fa8ebdd4244b8e652cc5341c3d5b4b06f84a637
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8115c35bf3ee575cfc9c51ac9853f58a21a43dc
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=392db38058eb47250a9d0cc737af37e78a7e443d

We also try to fix the issue in the same way.

Note:
A lot of structs and functions in ltp_tbio.ko module based on old kernel(e.g. 3.10.0) has been changed on upstream kernel, so ltp_tbio.ko module cannot be built on upstream kernel. Perhaps ltp_tbio.ko module needs to be updated, but we want to fix the issue first.

Signed-off-by Xiao Yang <[email protected]>

---
 testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c +1 -1

index 48cc588..0a9cd40 100644
@@ -562,8 +562,8 @@ module_init(tbio_init);
 
 static void tbio_exit(void)
 {
-	blk_cleanup_queue(tbio_dev.q);
 	del_gendisk(tbio_dev.gd);
+	blk_cleanup_queue(tbio_dev.q);
 	put_disk(tbio_dev.gd);
 	unregister_blkdev(TBIO_MAJOR, DEVICE_NAME);
 	vfree(tbio_dev.data);

Quoted 3 lines

Removing ltp_tbio.ko module always reproduced a warning and panic on the old kernels that have backported kernel commit a063057d7c73 (e.g. RHEL7.6).

Hi,

Sorry, the RHEL version is sensltive, so please remove it when pushing the patch.

Best Regards,
Xiao Yang

Quoted 37 lines

Removing ltp_tbio.ko module calls blk_cleanup_queue() and del_gendisk() in the order so that it triggers races or warnings since commit a063057d7c73
in kernel, and some kernel modules have fixed the issue, as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57678e5a3d5145e5f08aa1d307ba219b27b1765a
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0fa8ebdd4244b8e652cc5341c3d5b4b06f84a637
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8115c35bf3ee575cfc9c51ac9853f58a21a43dc
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=392db38058eb47250a9d0cc737af37e78a7e443d

We also try to fix the issue in the same way.

Note:
A lot of structs and functions in ltp_tbio.ko module based on old kernel(e.g. 3.10.0) has been changed on upstream kernel, so ltp_tbio.ko module cannot be built on upstream kernel. Perhaps ltp_tbio.ko module needs to be updated, but we want to fix the issue first.

Signed-off-by Xiao Yang <[email protected]>

---
 testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c +1 -1

index 48cc588..0a9cd40 100644
@@ -562,8 +562,8 @@ module_init(tbio_init);
 
 static void tbio_exit(void)
 {
-	blk_cleanup_queue(tbio_dev.q);
 	del_gendisk(tbio_dev.gd);
+	blk_cleanup_queue(tbio_dev.q);
 	put_disk(tbio_dev.gd);
 	unregister_blkdev(TBIO_MAJOR, DEVICE_NAME);
 	vfree(tbio_dev.data);

Removing ltp_tbio.ko module always reproduced a warning and panic on the old kernels that have backported kernel commit a063057d7c73 (e.g. RHEL7.6).

Removing ltp_tbio.ko module calls blk_cleanup_queue() and del_gendisk() in the order so that it triggers races or warnings since commit a063057d7c73 in kernel, and some kernel modules have fixed the issue, as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57678e5a3d5145e5f08aa1d307ba219b27b1765a
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0fa8ebdd4244b8e652cc5341c3d5b4b06f84a637
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8115c35bf3ee575cfc9c51ac9853f58a21a43dc
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=392db38058eb47250a9d0cc737af37e78a7e443d

We also try to fix the issue in the same way.

Note:
A lot of structs and functions in ltp_tbio.ko module based on old kernel(e.g. 3.10.0) has been changed on upstream kernel, so ltp_tbio.ko module cannot be built on upstream kernel. Perhaps ltp_tbio.ko module needs to be updated, but we want to fix the issue first.

Signed-off-by Xiao Yang <[email protected]>

---
 testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

testcases/kernel/device-drivers/tbio/tbio_kernel/ltp_tbio.c +1 -1

index 48cc588..0a9cd40 100644
@@ -562,8 +562,8 @@ module_init(tbio_init);
 
 static void tbio_exit(void)
 {
-	blk_cleanup_queue(tbio_dev.q);
 	del_gendisk(tbio_dev.gd);
+	blk_cleanup_queue(tbio_dev.q);
 	put_disk(tbio_dev.gd);
 	unregister_blkdev(TBIO_MAJOR, DEVICE_NAME);
 	vfree(tbio_dev.data);