Skip tests if scsi_debug module is already loaded and in use

Several tests across block/, scsi/, dm/, md/, zbd/, nvme/ require exclusive
access to the scsi_debug module because they load, unload or reconfigure it.
When scsi_debug is already loaded by the environment (e.g., by another
driver or a previous setup), these tests fail with:

modprobe: FATAL: Module scsi_debug is in use.
Unloading scsi_debug failed

scsi_debug            327680  4

Instead of modifying common rc files—which would overskip unrelated tests,
this patch adds "_module_not_in_use scsi_debug" only to the tests that
actually depend on exclusive access to scsi_debug.

Signed-off-by: Disha Goel <[email protected]>

Author: disgoel

common/scsi_debug

@@ -5,7 +5,25 @@
 # scsi_debug helper functions.
 
 _have_scsi_debug() {
-	_have_driver scsi_debug
+        _have_module scsi_debug
+        if [[ -d /sys/module/scsi_debug ]]; then
+                _module_not_in_use scsi_debug || return 1
+
+                if [[ -e /sys/bus/pseudo/drivers/scsi_debug/add_host ]]; then
+                        if [[ $(cat /sys/bus/pseudo/drivers/scsi_debug/add_host) -gt 1 ]]; then
+                                SKIP_REASON="scsi_debug already has multiple hosts configured"
+                                return 1
+                        fi
+                fi
+        fi
+}
+
+_have_loadable_scsi_debug() {
+         _have_scsi_debug || return 1
+         if [[ ! -f /sys/module/scsi_debug/initstate ]]; then
+                 SKIP_REASON="scsi_debug is built-in and cannot be reloaded"
+                 return 1
+         fi
 }
 
 SD_PARAM_PATH=/sys/module/scsi_debug/parameters

tests/block/025

@@ -12,7 +12,7 @@
 DESCRIPTION="do a huge discard with 4k sector size"
 
 requires() {
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 }
 
 test() {

tests/block/028

@@ -12,7 +12,7 @@ DESCRIPTION="do I/O on scsi_debug with DIF/DIX enabled"
 DMESG_FILTER="sed -r 's/(guard tag error at sector|ref tag error at location)/blktests failure: \\1/'"
 
 requires() {
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 }
 
 test_pi() {

tests/block/032

@@ -14,7 +14,7 @@ QUICK=1
 
 requires() {
 	_have_xfs
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 }
 
 test() {

tests/loop/004

@@ -12,7 +12,7 @@ QUICK=1
 
 requires() {
 	_have_program xfs_io
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 	_have_src_program loblksize
 	_have_loop_set_block_size
 }

tests/scsi/007

@@ -12,7 +12,7 @@ DESCRIPTION="Trigger the SCSI error handler"
 QUICK=1
 
 requires() {
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 }
 
 start_tracing() {

tests/zbd/008

@@ -13,7 +13,7 @@ DESCRIPTION="check no stale page cache after BLKZONERESET and data read race"
 TIMED=1
 
 requires() {
-	_have_module scsi_debug
+	_have_loadable_scsi_debug
 	_have_module_param scsi_debug zbc
 	_have_program xfs_io
 }