Shrinkers are now registered with a name.

v5.19-rc4-52-ge33c267ab70d Adds shrinker names to the registration
call to aid with shrinker debugging, which is highly opaque.

To enable you'll have to recompile the kernel with
CONFIG_SHRINKER_DEBUG=y though, since it's disabled by default in
OSV kernels.

Signed-off-by: Auke Kok <auke.kok@versity.com>

kmod/src/Makefile.kernelcompat

@@ -362,3 +362,11 @@ endif
 ifneq (,$(shell grep -s '^struct __kernel_old_timeval .' include/uapi/linux/time_types.h))
 ccflags-y += -DKC_KERNEL_OLD_TIMEVAL_STRUCT
 endif
+
+#
+# v5.19-rc4-52-ge33c267ab70d
+#
+# register_shrinker now requires a name, used for debug stats etc.
+ifneq (,$(shell grep 'int __printf.*register_shrinker.struct shrinker .shrinker,' include/linux/shrinker.h))
+ccflags-y += -DKC_SHRINKER_NAME
+endif

kmod/src/block.c

@@ -1297,7 +1297,7 @@ int scoutfs_block_setup(struct super_block *sb)
 	init_waitqueue_head(&binf->waitq);
 	KC_INIT_SHRINKER_FUNCS(&binf->shrinker, block_count_objects,
 			       block_scan_objects);
-	KC_REGISTER_SHRINKER(&binf->shrinker);
+	KC_REGISTER_SHRINKER(&binf->shrinker, "scoutfs-block:" SCSBF, SCSB_ARGS(sb));
 	INIT_WORK(&binf->free_work, block_free_work);
 	init_llist_head(&binf->free_llist);
 

kmod/src/item.c

@@ -2693,7 +2693,7 @@ int scoutfs_item_setup(struct super_block *sb)
 
 	KC_INIT_SHRINKER_FUNCS(&cinf->shrinker, item_cache_count_objects,
 			       item_cache_scan_objects);
-	KC_REGISTER_SHRINKER(&cinf->shrinker);
+	KC_REGISTER_SHRINKER(&cinf->shrinker, "scoutfs-item:" SCSBF, SCSB_ARGS(sb));
 #ifdef KC_CPU_NOTIFIER
         cinf->notifier.notifier_call = item_cpu_callback;
         register_hotcpu_notifier(&cinf->notifier);

kmod/src/kernelcompat.h

@@ -197,7 +197,11 @@ struct timespec64 kc_current_time(struct inode *inode);
 } while (0)
 
 #define KC_SHRINKER_CONTAINER_OF(ptr, type) container_of(ptr, type, shrinker)
-#define KC_REGISTER_SHRINKER(ptr) (register_shrinker(ptr))
+#ifdef KC_SHRINKER_NAME
+#define KC_REGISTER_SHRINKER register_shrinker
+#else
+#define KC_REGISTER_SHRINKER(ptr, fmt, ...) (register_shrinker(ptr))
+#endif /* KC_SHRINKER_NAME */
 #define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(ptr))
 #define KC_SHRINKER_FN(ptr) (ptr)
 #else
@@ -224,7 +228,7 @@ struct kc_shrinker_wrapper {
 	_wrap->shrink.seeks = DEFAULT_SEEKS;			\
 } while (0)
 #define KC_SHRINKER_CONTAINER_OF(ptr, type) container_of(container_of(ptr, struct kc_shrinker_wrapper, shrink), type, shrinker)
-#define KC_REGISTER_SHRINKER(ptr) (register_shrinker(ptr.shrink))
+#define KC_REGISTER_SHRINKER(ptr, fmt, ...) (register_shrinker(ptr.shrink))
 #define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(ptr.shrink))
 #define KC_SHRINKER_FN(ptr) (ptr.shrink)
 

kmod/src/lock.c

@@ -1732,7 +1732,7 @@ int scoutfs_lock_setup(struct super_block *sb)
 	linfo->lock_range_tree = RB_ROOT;
 	KC_INIT_SHRINKER_FUNCS(&linfo->shrinker, lock_count_objects,
 			       lock_scan_objects);
-	KC_REGISTER_SHRINKER(&linfo->shrinker);
+	KC_REGISTER_SHRINKER(&linfo->shrinker, "scoutfs-lock:" SCSBF, SCSB_ARGS(sb));
 	INIT_LIST_HEAD(&linfo->lru_list);
 	INIT_WORK(&linfo->inv_work, lock_invalidate_worker);
 	INIT_LIST_HEAD(&linfo->inv_list);

kmod/src/quota.c

@@ -1226,7 +1226,7 @@ int scoutfs_quota_setup(struct super_block *sb)
 	init_waitqueue_head(&qtinf->waitq);
 
 	KC_INIT_SHRINKER_FUNCS(&qtinf->shrinker, count_cached_checks, scan_cached_checks);
-	KC_REGISTER_SHRINKER(&qtinf->shrinker);
+	KC_REGISTER_SHRINKER(&qtinf->shrinker, "scoutfs-quota:" SCSBF, SCSB_ARGS(sb));
 
 	sbi->squota_info = qtinf;
 

kmod/src/wkic.c

@@ -1113,7 +1113,7 @@ int scoutfs_wkic_setup(struct super_block *sb)
 
 	winf->sb = sb;
 	KC_INIT_SHRINKER_FUNCS(&winf->shrinker, wkic_shrink_count, wkic_shrink_scan);
-	KC_REGISTER_SHRINKER(&winf->shrinker);
+	KC_REGISTER_SHRINKER(&winf->shrinker, "scoutfs-weak_item:" SCSBF, SCSB_ARGS(sb));
 
 	sbi->wkic_info = winf;
 	return 0;