diff --git a/kmod/src/Makefile b/kmod/src/Makefile
index fa632aa1..9aea4571 100644
--- a/kmod/src/Makefile
+++ b/kmod/src/Makefile
@@ -60,11 +60,11 @@ scoutfs-y +=			\
 #
 .PHONY: $(src)/check_exported_types
 $(src)/check_exported_types:
-	@if egrep '\<[us](8|16|32|64\>)' $(src)/format.h $(src)/ioctl.h; then \
+	@if grep -E '\<[us](8|16|32|64\>)' $(src)/format.h $(src)/ioctl.h; then \
 		echo "no raw types in exported headers, preface with __";     \
 		exit 1;							      \
 	fi
-	@if egrep '\<__packed\>' $(src)/format.h $(src)/ioctl.h; then \
+	@if grep -E '\<__packed\>' $(src)/format.h $(src)/ioctl.h; then \
 		echo "no __packed allowed in exported headers";     \
 		exit 1;							      \
 	fi
diff --git a/kmod/src/Makefile.kernelcompat b/kmod/src/Makefile.kernelcompat
index 81dc8a58..686fc419 100644
--- a/kmod/src/Makefile.kernelcompat
+++ b/kmod/src/Makefile.kernelcompat
@@ -496,3 +496,131 @@ endif
 ifneq (,$(shell grep 'struct posix_acl.*get_inode_acl' include/linux/fs.h))
 ccflags-y += -DKC_GET_INODE_ACL
 endif
+
+#
+# v6.1-rc5-2-ge9a688bcb193
+#
+# get_random_u32_below() implementation
+ifneq (,$(shell grep 'u32 get_random_u32_below' include/linux/random.h))
+ccflags-y += -DKC_HAVE_GET_RANDOM_U32_BELOW
+endif
+
+# v6.5-rc1-7-g9b6304c1d537
+#
+# ctime accessor methods
+ifneq (,$(shell grep 'timespec64 inode_set_ctime_current' include/linux/fs.h))
+ccflags-y += -DKC_FS_INODE_C_TIME_ACCESSOR
+endif
+
+#
+# v6.6-rc5-1-g077c212f0344
+#
+# Must use access methods from fs.h to get to inode ctime/mtime/atime
+ifneq (,$(shell grep 'inline time64_t inode_get_atime_sec' include/linux/fs.h))
+ccflags-y += -DKC_FS_INODE_AM_TIME_ACCESSOR
+endif
+
+#
+# v6.12-rc1-3-g5f60d5f6bbc1
+#
+# asm/unaligned.h replaced with linux/unaligned.h
+ifneq (,$(shell grep -s 'define __LINUX_UNALIGNED_H' include/linux/unaligned.h))
+ccflags-y += -DKC_HAVE__LINUX_UNALIGNED_H
+endif
+
+#
+# v6.9-rc4-29-g203c1ce0bb06
+#
+# RIP bd_inode. (note, struct moved between headers!)
+ifneq (,$(shell grep -s 'struct inode.*bd_inode' include/linux/blk_types.h include/linux/fs.h))
+ccflags-y += -DKC_HAVE_BD_INODE
+endif
+
+#
+# v6.8-9146-gc759e609030c
+#
+# Removes __assign_str_len() and removes the 2nd param of __assign_str().
+ifneq (,$(shell grep -s 'define __assign_str.dst, src' \
+				include/trace/trace_events.h \
+				include/trace/ftrace.h \
+				include/trace/stages/stage6_event_callback.h))
+ccflags-y += -DKC_HAVE_ASSIGN_STR_PARMS
+endif
+
+#
+# v6.5-113-g615e95831ec3
+#
+ifneq (,$(shell grep 'generic_fillattr..*,.u32,' include/linux/fs.h))
+ccflags-y += -DKC_GENERIC_FILLATTR_REQUEST_MASK
+endif
+
+#
+# v6.6-rc4-53-gc42d50aefd17
+#
+# el10 yet again modifies the shrinker API significantly, breaking our current
+# implementation.
+ifneq (,$(shell grep 'struct shrinker .shrinker_alloc' include/linux/shrinker.h))
+ccflags-y += -DKC_SHRINKER_ALLOC
+endif
+
+#
+# v6.9-rc4-8-gead083aeeed9
+#
+# set_blocksize() now has a struct file arg.
+ifneq (,$(shell grep -s 'int set_blocksize.struct file' include/linux/blkdev.h))
+ccflags-y += -DKC_BLKDEV_SET_BLOCKSIZE_FILE
+endif
+
+#
+# v5.1-rc3-29-gaa30f47cf666
+#
+# struct kobj_type now has member `default_groups`
+ifneq (,$(shell grep 'const struct attribute_group ..default_groups;' include/linux/kobject.h))
+ccflags-y += -DKC_KOBJECT_DEFAULT_GROUPS
+endif
+
+#
+# v6.7-rc4-307-g17bf23a981be
+#
+# block_write_full_page() is replaced with block_write_full_folio(),
+# but that isn't exported as it used to be (and the only users now
+# are builtin). However, the kernel will fall back to using the
+# .writepages method instead, so we can drop this method.
+ifneq (,$(shell grep 'int block_write_full_page.struct page' include/linux/buffer_head.h))
+ccflags-y += -DKC_HAVE_BLOCK_WRITE_FULL_PAGE
+endif
+
+#
+# v6.4-rc2-29-gc6585011bc1d
+#
+# generic_file_splice_read is removed. It can be replaced with filemap_splice_read
+# or copy_splice_read.
+ifneq (,$(shell grep 'ssize_t generic_file_splice_read.struct file' include/linux/fs.h))
+ccflags-y += -DKC_HAVE_GENERIC_FILE_SPLICE_READ
+endif
+
+#
+# v5.19-rc3-395-g67235182a41c
+#
+# Adds buffer_migrate_folio(), similar to other fss. Quote willy: "If the filesystem
+# implements migrate_folio and writepages, there is no need for a writepage implementation."
+ifneq (,$(shell grep 'int buffer_migrate_folio.struct address_space' include/linux/buffer_head.h))
+ccflags-y += -DKC_HAVE_BUFFER_MIGRATE_FOLIO
+endif
+
+#
+# v4.6-rc3-29-g6192269444eb
+#
+# Adds .iterate_shared readdir() iterator vfs method.
+ifneq (,$(shell grep 'iterate_shared...struct file.., struct dir_context' include/linux/fs.h))
+ccflags-y += -DKC_HAVE_ITERATE_SHARED
+endif
+
+#
+# v6.11-rc1-54-g9f04609f74ec
+#
+# Last of a series of changes that make block_write_begin/end take a folio instead of
+# a struct pagep.
+ifneq (,$(shell grep 'int __block_write_begin.struct.folio' include/linux/buffer_head.h))
+ccflags-y += -DKC_BLOCK_WRITE_BEGIN_FOLIO
+endif
diff --git a/kmod/src/acl.c b/kmod/src/acl.c
index 356e3107..be1aed4e 100644
--- a/kmod/src/acl.c
+++ b/kmod/src/acl.c
@@ -197,7 +197,7 @@ int scoutfs_set_acl_locked(struct inode *inode, struct posix_acl *acl, int type,
 		if (!value) {
 			/* can be setting an acl that only affects mode, didn't need xattr */
 			inode_inc_iversion(inode);
-			inode->i_ctime = current_time(inode);
+			inode_set_ctime_current(inode);
 		}
 	}
 
diff --git a/kmod/src/alloc.c b/kmod/src/alloc.c
index 0ceaf3b8..21cbebda 100644
--- a/kmod/src/alloc.c
+++ b/kmod/src/alloc.c
@@ -308,14 +308,14 @@ static bool invalid_extent(u64 start, u64 end, u64 first, u64 last)
 static bool invalid_meta_blkno(struct super_block *sb, u64 blkno)
 {
 	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
-	u64 last_meta = (i_size_read(sbi->meta_bdev->bd_inode) >> SCOUTFS_BLOCK_LG_SHIFT) - 1;
+	u64 last_meta = (i_size_read(KC_BDEV_INODE(sbi->meta_bdev)) >> SCOUTFS_BLOCK_LG_SHIFT) - 1;
 
 	return invalid_extent(blkno, blkno, SCOUTFS_META_DEV_START_BLKNO, last_meta);
 }
 
 static bool invalid_data_extent(struct super_block *sb, u64 start, u64 len)
 {
-	u64 last_data = (i_size_read(sb->s_bdev->bd_inode) >> SCOUTFS_BLOCK_SM_SHIFT) - 1;
+	u64 last_data = (i_size_read(KC_BDEV_INODE(sb->s_bdev)) >> SCOUTFS_BLOCK_SM_SHIFT) - 1;
 
 	return invalid_extent(start, start + len - 1, SCOUTFS_DATA_DEV_START_BLKNO, last_data);
 }
diff --git a/kmod/src/attr_x.c b/kmod/src/attr_x.c
index 39e84a36..409c9c79 100644
--- a/kmod/src/attr_x.c
+++ b/kmod/src/attr_x.c
@@ -103,8 +103,8 @@ int scoutfs_get_attr_x(struct inode *inode, struct scoutfs_ioctl_inode_attr_x *i
 		size = fill_attr(size, iax, SCOUTFS_IOC_IAX_OFFLINE_BLOCKS,
 				 offline_blocks, offline);
 	}
-	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CTIME, ctime_sec, inode->i_ctime.tv_sec);
-	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CTIME, ctime_nsec, inode->i_ctime.tv_nsec);
+	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CTIME, ctime_sec, inode_get_ctime_sec(inode));
+	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CTIME, ctime_nsec, inode_get_ctime_nsec(inode));
 	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CRTIME, crtime_sec, si->crtime.tv_sec);
 	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_CRTIME, crtime_nsec, si->crtime.tv_nsec);
 	size = fill_attr(size, iax, SCOUTFS_IOC_IAX_SIZE, size, i_size_read(inode));
@@ -223,10 +223,8 @@ int scoutfs_set_attr_x(struct inode *inode, struct scoutfs_ioctl_inode_attr_x *i
 		scoutfs_inode_set_data_version(inode, iax->data_version);
 	if (iax->x_mask & SCOUTFS_IOC_IAX_SIZE)
 		i_size_write(inode, iax->size);
-	if (iax->x_mask & SCOUTFS_IOC_IAX_CTIME) {
-		inode->i_ctime.tv_sec = iax->ctime_sec;
-		inode->i_ctime.tv_nsec = iax->ctime_nsec;
-	}
+	if (iax->x_mask & SCOUTFS_IOC_IAX_CTIME)
+		inode_set_ctime(inode, iax->ctime_sec, iax->ctime_nsec);
 	if (iax->x_mask & SCOUTFS_IOC_IAX_CRTIME) {
 		si->crtime.tv_sec = iax->crtime_sec;
 		si->crtime.tv_nsec = iax->crtime_nsec;
diff --git a/kmod/src/block.c b/kmod/src/block.c
index 463e1b01..ca92f6b1 100644
--- a/kmod/src/block.c
+++ b/kmod/src/block.c
@@ -884,7 +884,7 @@ int scoutfs_block_dirty_ref(struct super_block *sb, struct scoutfs_alloc *alloc,
 	hdr->magic = cpu_to_le32(magic);
 	hdr->fsid = cpu_to_le64(sbi->fsid);
 	hdr->blkno = cpu_to_le64(bl->blkno);
-	prandom_bytes(&hdr->seq, sizeof(hdr->seq));
+	get_random_bytes(&hdr->seq, sizeof(hdr->seq));
 
 	trace_scoutfs_block_dirty_ref(sb, le64_to_cpu(ref->blkno), le64_to_cpu(ref->seq),
 				      le64_to_cpu(hdr->blkno), le64_to_cpu(hdr->seq));
@@ -1229,7 +1229,12 @@ static int sm_block_io(struct super_block *sb, struct block_device *bdev, blk_op
 	kc_bio_set_sector(bio, blkno << (SCOUTFS_BLOCK_SM_SHIFT - 9));
 	bio->bi_end_io = sm_block_bio_end_io;
 	bio->bi_private = &sbc;
-	bio_add_page(bio, page, SCOUTFS_BLOCK_SM_SIZE, 0);
+	ret = bio_add_page(bio, page, SCOUTFS_BLOCK_SM_SIZE, 0);
+	if (ret != SCOUTFS_BLOCK_SM_SIZE) {
+		bio_put(bio);
+		ret = -EFAULT;
+		goto out;
+	}
 
 	init_completion(&sbc.comp);
 	sbc.err = 0;
@@ -1285,9 +1290,12 @@ int scoutfs_block_setup(struct super_block *sb)
 
 	binf->sb = sb;
 	init_waitqueue_head(&binf->waitq);
-	KC_INIT_SHRINKER_FUNCS(&binf->shrinker, block_count_objects,
-			       block_scan_objects);
-	KC_REGISTER_SHRINKER(&binf->shrinker, "scoutfs-block:" SCSBF, SCSB_ARGS(sb));
+	KC_SETUP_SHRINKER(binf->shrinker, binf, 0, block_count_objects,
+			  block_scan_objects, "scoutfs-block:" SCSBF, SCSB_ARGS(sb));
+	if (KC_SHRINKER_IS_NULL(binf->shrinker)) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	INIT_WORK(&binf->free_work, block_free_work);
 	init_llist_head(&binf->free_llist);
 
@@ -1309,7 +1317,7 @@ void scoutfs_block_destroy(struct super_block *sb)
 	struct block_info *binf = SCOUTFS_SB(sb)->block_info;
 
 	if (binf) {
-		KC_UNREGISTER_SHRINKER(&binf->shrinker);
+		KC_UNREGISTER_SHRINKER(binf->shrinker);
 		block_shrink_all(sb);
 		flush_work(&binf->free_work);
 		rhashtable_destroy(&binf->ht);
diff --git a/kmod/src/btree.c b/kmod/src/btree.c
index 7a21afc7..c6baa3be 100644
--- a/kmod/src/btree.c
+++ b/kmod/src/btree.c
@@ -2042,7 +2042,7 @@ struct merged_item {
 	u64 seq;
 	u8 flags;
 	unsigned int val_len;
-	u8 val[0];
+	u8 val[];
 };
 
 static inline struct merged_item *mitem_container(struct rb_node *node)
@@ -2208,7 +2208,7 @@ static int merge_read_item(struct super_block *sb, struct scoutfs_key *key, u64
 	mitem->flags = flags;
 	mitem->val_len = val_len;
 	if (val_len)
-		memcpy(mitem->val, val, val_len);
+		memcpy(&mitem->val[0], val, val_len);
 
 	if (found) {
 		replace_mitem(rng, found, mitem);
diff --git a/kmod/src/btree.h b/kmod/src/btree.h
index 8656dd65..065c190e 100644
--- a/kmod/src/btree.h
+++ b/kmod/src/btree.h
@@ -30,7 +30,7 @@ struct scoutfs_btree_item_list {
 	u64 seq;
 	u8 flags;
 	int val_len;
-	u8 val[0];
+	u8 val[];
 };
 
 int scoutfs_btree_lookup(struct super_block *sb,
diff --git a/kmod/src/counters.c b/kmod/src/counters.c
index 5578ae26..9ba5b1a7 100644
--- a/kmod/src/counters.c
+++ b/kmod/src/counters.c
@@ -34,6 +34,17 @@ static struct attribute scoutfs_counter_attrs[] = {
 #define NR_ATTRS ARRAY_SIZE(scoutfs_counter_attrs)
 static struct attribute *scoutfs_counter_attr_ptrs[NR_ATTRS + 1];
 
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+static struct attribute_group scoutfs_counter_attr_group = {
+	.attrs = scoutfs_counter_attr_ptrs,
+};
+
+static const struct attribute_group *scoutfs_counter_attr_groups[] = {
+	&scoutfs_counter_attr_group,
+	NULL,
+};
+#endif
+
 static ssize_t scoutfs_counter_attr_show(struct kobject *kobj,
 				         struct attribute *attr, char *buf)
 {
@@ -45,7 +56,6 @@ static ssize_t scoutfs_counter_attr_show(struct kobject *kobj,
 	counters = container_of(kobj, struct scoutfs_counters, kobj);
 	index = attr - scoutfs_counter_attrs;
 	pcpu = &counters->FIRST_COUNTER + index;
-
 	return snprintf(buf, PAGE_SIZE, "%lld\n", percpu_counter_sum(pcpu));
 }
 
@@ -63,7 +73,7 @@ static const struct sysfs_ops scoutfs_counter_attr_ops = {
 };
 
 static struct kobj_type scoutfs_counters_ktype = {
-	.default_attrs  = scoutfs_counter_attr_ptrs,
+	.KC_KOBJ_DEFAULT_OP = KC_KOBJ_DEFAULT_PICK(scoutfs_counter_attr_groups, scoutfs_counter_attr_ptrs),
 	.sysfs_ops      = &scoutfs_counter_attr_ops,
 	.release        = scoutfs_counters_kobj_release,
 };
diff --git a/kmod/src/data.c b/kmod/src/data.c
index 7903e8d7..ce38c4be 100644
--- a/kmod/src/data.c
+++ b/kmod/src/data.c
@@ -716,24 +716,24 @@ static int scoutfs_readpage(struct file *file, struct page *page)
 		return ret;
 	}
 
-	if (scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, inode_lock)) {
-		ret = scoutfs_data_wait_check(inode, page_offset(page),
-					      PAGE_SIZE, SEF_OFFLINE,
-					      SCOUTFS_IOC_DWO_READ, &dw,
-					      inode_lock);
-		if (ret != 0) {
-			unlock_page(page);
-			scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
-			scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
-		}
-		if (ret > 0) {
-			ret = scoutfs_data_wait(inode, &dw);
-			if (ret == 0)
-				ret = AOP_TRUNCATED_PAGE;
-		}
-		if (ret != 0)
-			return ret;
+	scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, inode_lock);
+
+	ret = scoutfs_data_wait_check(inode, page_offset(page),
+				      PAGE_SIZE, SEF_OFFLINE,
+				      SCOUTFS_IOC_DWO_READ, &dw,
+				      inode_lock);
+	if (ret != 0) {
+		unlock_page(page);
+		scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
+		scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
 	}
+	if (ret > 0) {
+		ret = scoutfs_data_wait(inode, &dw);
+		if (ret == 0)
+			ret = AOP_TRUNCATED_PAGE;
+	}
+	if (ret != 0)
+		return ret;
 
 #ifdef KC_MPAGE_READ_FOLIO
 	ret = mpage_read_folio(folio, scoutfs_get_block_read);
@@ -741,8 +741,8 @@ static int scoutfs_readpage(struct file *file, struct page *page)
 	ret = mpage_readpage(page, scoutfs_get_block_read);
 #endif
 
-	scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
 	scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
+	scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
 
 	return ret;
 }
@@ -760,8 +760,10 @@ static int scoutfs_readpages(struct file *file, struct address_space *mapping,
 			     struct list_head *pages, unsigned nr_pages)
 {
 	struct inode *inode = file->f_inode;
+	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 	struct super_block *sb = inode->i_sb;
 	struct scoutfs_lock *inode_lock = NULL;
+	SCOUTFS_DECLARE_PER_TASK_ENTRY(pt_ent);
 	struct page *page;
 	struct page *tmp;
 	int ret;
@@ -771,6 +773,8 @@ static int scoutfs_readpages(struct file *file, struct address_space *mapping,
 	if (ret)
 		goto out;
 
+	scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, inode_lock);
+
 	list_for_each_entry_safe(page, tmp, pages, lru) {
 		ret = scoutfs_data_wait_check(inode, page_offset(page),
 					      PAGE_SIZE, SEF_OFFLINE,
@@ -790,6 +794,7 @@ static int scoutfs_readpages(struct file *file, struct address_space *mapping,
 
 	ret = mpage_readpages(mapping, pages, nr_pages, scoutfs_get_block_read);
 out:
+	scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
 	scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
 	BUG_ON(!list_empty(pages));
 	return ret;
@@ -798,8 +803,10 @@ static int scoutfs_readpages(struct file *file, struct address_space *mapping,
 static void scoutfs_readahead(struct readahead_control *rac)
 {
 	struct inode *inode = rac->file->f_inode;
+	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 	struct super_block *sb = inode->i_sb;
 	struct scoutfs_lock *inode_lock = NULL;
+	SCOUTFS_DECLARE_PER_TASK_ENTRY(pt_ent);
 	int ret;
 
 	ret = scoutfs_lock_inode(sb, SCOUTFS_LOCK_READ,
@@ -807,6 +814,8 @@ static void scoutfs_readahead(struct readahead_control *rac)
 	if (ret)
 		return;
 
+	scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, inode_lock);
+
 	ret = scoutfs_data_wait_check(inode, readahead_pos(rac),
 				      readahead_length(rac), SEF_OFFLINE,
 				      SCOUTFS_IOC_DWO_READ, NULL,
@@ -814,14 +823,17 @@ static void scoutfs_readahead(struct readahead_control *rac)
 	if (ret == 0)
 		mpage_readahead(rac, scoutfs_get_block_read);
 
+	scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
 	scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_READ);
 }
 #endif
 
+#ifdef KC_HAVE_BLOCK_WRITE_FULL_PAGE
 static int scoutfs_writepage(struct page *page, struct writeback_control *wbc)
 {
 	return block_write_full_page(page, scoutfs_get_block_write, wbc);
 }
+#endif
 
 static int scoutfs_writepages(struct address_space *mapping,
 			      struct writeback_control *wbc)
@@ -841,7 +853,7 @@ static int scoutfs_write_begin(struct file *file,
 #ifdef KC_BLOCK_WRITE_BEGIN_AOP_FLAGS
 			       unsigned flags,
 #endif
-			       struct page **pagep, void **fsdata)
+			       KC_PAGE_OR_FOLIO(struct page **pagep, struct folio **folio), void **fsdata)
 {
 	struct inode *inode = mapping->host;
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
@@ -886,7 +898,7 @@ static int scoutfs_write_begin(struct file *file,
 #ifdef KC_BLOCK_WRITE_BEGIN_AOP_FLAGS
 				flags,
 #endif
-				pagep, scoutfs_get_block_write);
+				KC_PAGE_OR_FOLIO(pagep, folio), scoutfs_get_block_write);
 	if (ret < 0) {
 		scoutfs_release_trans(sb);
 		scoutfs_inode_index_unlock(sb, &wbd->ind_locks);
@@ -919,7 +931,8 @@ static int writepages_sync_none(struct address_space *mapping, loff_t start,
 
 static int scoutfs_write_end(struct file *file, struct address_space *mapping,
 			     loff_t pos, unsigned len, unsigned copied,
-			     struct page *page, void *fsdata)
+			     KC_PAGE_OR_FOLIO(struct page *pagep, struct folio *folio),
+			     void *fsdata)
 {
 	struct inode *inode = mapping->host;
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
@@ -927,10 +940,11 @@ static int scoutfs_write_end(struct file *file, struct address_space *mapping,
 	struct write_begin_data *wbd = fsdata;
 	int ret;
 
-	trace_scoutfs_write_end(sb, scoutfs_ino(inode), page->index, (u64)pos,
-				len, copied);
+	trace_scoutfs_write_end(sb, scoutfs_ino(inode),
+				KC_PAGE_OR_FOLIO(pagep->index, folio_index(folio)),
+				(u64)pos, len, copied);
 
-	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+	ret = generic_write_end(file, mapping, pos, len, copied, KC_PAGE_OR_FOLIO(pagep, folio), fsdata);
 	if (ret > 0) {
 		if (!si->staging) {
 			scoutfs_inode_set_data_seq(inode);
@@ -1483,12 +1497,14 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 
 		cur_time = current_time(from);
 		if (!is_stage) {
-			to->i_ctime = to->i_mtime = cur_time;
+			inode_set_ctime_to_ts(to, cur_time);
+			inode_set_mtime_to_ts(to, cur_time);
 			inode_inc_iversion(to);
 			scoutfs_inode_inc_data_version(to);
 			scoutfs_inode_set_data_seq(to);
 		}
-		from->i_ctime = from->i_mtime = cur_time;
+		inode_set_ctime_to_ts(from, cur_time);
+		inode_set_mtime_to_ts(from, cur_time);
 		inode_inc_iversion(from);
 		scoutfs_inode_inc_data_version(from);
 		scoutfs_inode_set_data_seq(from);
@@ -1967,7 +1983,11 @@ static int scoutfs_data_page_mkwrite(struct vm_area_struct *vma,
 				     struct vm_fault *vmf)
 {
 #endif
+#ifdef KC_MPAGE_READ_FOLIO
+	struct folio *folio = page_folio(vmf->page);
+#else
 	struct page *page = vmf->page;
+#endif
 	struct file *file = vma->vm_file;
 	struct inode *inode = file_inode(file);
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
@@ -2035,27 +2055,50 @@ static int scoutfs_data_page_mkwrite(struct vm_area_struct *vma,
 
 	down_write(&si->extent_sem);
 
+#ifdef KC_MPAGE_READ_FOLIO
+	if (!folio_trylock(folio)) {
+#else
 	if (!trylock_page(page)) {
+#endif
 		ret = VM_FAULT_NOPAGE;
 		goto out_sem;
 	}
 	ret = VM_FAULT_LOCKED;
 
+#ifdef KC_MPAGE_READ_FOLIO
+	if ((folio->mapping != inode->i_mapping) ||
+	    (!folio_test_uptodate(folio)) ||
+	    (folio_pos(folio) > size)) {
+		folio_unlock(folio);
+#else
 	if ((page->mapping != inode->i_mapping) ||
 	    (!PageUptodate(page)) ||
-	    (page_offset(page) > size))	 {
+	    (page_offset(page) > size)) {
 		unlock_page(page);
+#endif
 		ret = VM_FAULT_NOPAGE;
 		goto out_sem;
 	}
 
+#ifdef KC_MPAGE_READ_FOLIO
+	if (folio_index(folio) == (size - 1) >> PAGE_SHIFT)
+#else
 	if (page->index == (size - 1) >> PAGE_SHIFT)
+#endif
 		len = ((size - 1) & ~PAGE_MASK) + 1;
 
+#ifdef KC_MPAGE_READ_FOLIO
+	err = __block_write_begin(KC_PAGE_OR_FOLIO(folio_page(folio, 0), folio), pos, PAGE_SIZE, scoutfs_get_block);
+#else
 	err = __block_write_begin(page, pos, PAGE_SIZE, scoutfs_get_block);
+#endif
 	if (err) {
 		ret = vmf_error(err);
+#ifdef KC_MPAGE_READ_FOLIO
+		folio_unlock(folio);
+#else
 		unlock_page(page);
+#endif
 		goto out_sem;
 	}
 	/* end scoutfs_write_begin */
@@ -2065,8 +2108,13 @@ static int scoutfs_data_page_mkwrite(struct vm_area_struct *vma,
 	 * progress, we are guaranteed that writeback during freezing will
 	 * see the dirty page and writeprotect it again.
 	 */
+#ifdef KC_MPAGE_READ_FOLIO
+	folio_mark_dirty(folio);
+	folio_wait_stable(folio);
+#else
 	set_page_dirty(page);
 	wait_for_stable_page(page);
+#endif
 
 	/* scoutfs_write_end */
 	scoutfs_inode_set_data_seq(inode);
@@ -2193,6 +2241,9 @@ const struct address_space_operations scoutfs_file_aops = {
 	.dirty_folio		= block_dirty_folio,
 	.invalidate_folio	= block_invalidate_folio,
 	.read_folio		= scoutfs_read_folio,
+#ifdef KC_HAVE_BUFFER_MIGRATE_FOLIO
+	.migrate_folio		= buffer_migrate_folio,
+#endif
 #else
 	.readpage		= scoutfs_readpage,
 #endif
@@ -2201,7 +2252,9 @@ const struct address_space_operations scoutfs_file_aops = {
 #else
 	.readahead		= scoutfs_readahead,
 #endif
+#ifdef KC_HAVE_BLOCK_WRITE_FULL_PAGE
 	.writepage		= scoutfs_writepage,
+#endif
 	.writepages		= scoutfs_writepages,
 	.write_begin		= scoutfs_write_begin,
 	.write_end		= scoutfs_write_end,
@@ -2216,8 +2269,12 @@ const struct file_operations scoutfs_file_fops = {
 #else
 	.read_iter	= scoutfs_file_read_iter,
 	.write_iter	= scoutfs_file_write_iter,
-	.splice_read	= generic_file_splice_read,
 	.splice_write	= iter_file_splice_write,
+#endif
+#ifdef KC_HAVE_GENERIC_FILE_SPLICE_READ
+	.splice_read	= generic_file_splice_read,
+#else
+	.splice_read	= copy_splice_read,
 #endif
 	.mmap		= scoutfs_file_mmap,
 	.unlocked_ioctl	= scoutfs_ioctl,
diff --git a/kmod/src/dir.c b/kmod/src/dir.c
index d2343e58..2e5168b5 100644
--- a/kmod/src/dir.c
+++ b/kmod/src/dir.c
@@ -759,6 +759,7 @@ static int scoutfs_mknod(KC_VFS_NS_DEF
 	struct scoutfs_lock *dir_lock = NULL;
 	struct scoutfs_lock *inode_lock = NULL;
 	struct scoutfs_inode_info *si;
+	struct kc_timespec cur_time;
 	LIST_HEAD(ind_locks);
 	u64 hash;
 	u64 pos;
@@ -790,9 +791,13 @@ static int scoutfs_mknod(KC_VFS_NS_DEF
 	set_dentry_fsdata(dentry, dir_lock);
 
 	i_size_write(dir, i_size_read(dir) + dentry->d_name.len);
-	dir->i_mtime = dir->i_ctime = current_time(inode);
-	inode->i_mtime = inode->i_atime = inode->i_ctime = dir->i_mtime;
-	si->crtime = inode->i_mtime;
+	cur_time = current_time(inode);
+	inode_set_mtime_to_ts(dir, cur_time);
+	inode_set_ctime_to_ts(dir, cur_time);
+	inode_set_mtime_to_ts(inode, cur_time);
+	inode_set_atime_to_ts(inode, cur_time);
+	inode_set_ctime_to_ts(inode, cur_time);
+	si->crtime = inode_get_mtime(inode);
 	inode_inc_iversion(dir);
 	inode_inc_iversion(inode);
 	scoutfs_forest_inc_inode_count(sb);
@@ -845,6 +850,7 @@ static int scoutfs_link(struct dentry *old_dentry,
 	struct scoutfs_lock *dir_lock;
 	struct scoutfs_lock *inode_lock = NULL;
 	struct scoutfs_lock *orph_lock = NULL;
+	struct kc_timespec cur_time;
 	LIST_HEAD(ind_locks);
 	bool del_orphan = false;
 	u64 dir_size;
@@ -919,8 +925,10 @@ static int scoutfs_link(struct dentry *old_dentry,
 	set_dentry_fsdata(dentry, dir_lock);
 
 	i_size_write(dir, dir_size);
-	dir->i_mtime = dir->i_ctime = current_time(inode);
-	inode->i_ctime = dir->i_mtime;
+	cur_time = current_time(inode);
+	inode_set_mtime_to_ts(dir, cur_time);
+	inode_set_ctime_to_ts(dir, cur_time);
+	inode_set_ctime_to_ts(inode, inode_get_mtime(dir));
 	inc_nlink(inode);
 	inode_inc_iversion(dir);
 	inode_inc_iversion(inode);
@@ -1030,13 +1038,13 @@ static int scoutfs_unlink(struct inode *dir, struct dentry *dentry)
 
 	set_dentry_fsdata(dentry, dir_lock);
 
-	dir->i_ctime = ts;
-	dir->i_mtime = ts;
+	inode_set_ctime_to_ts(dir, ts);
+	inode_set_mtime_to_ts(dir, ts);
 	i_size_write(dir, i_size_read(dir) - dentry->d_name.len);
 	inode_inc_iversion(dir);
 	inode_inc_iversion(inode);
 
-	inode->i_ctime = ts;
+	inode_set_ctime_to_ts(inode, ts);
 	drop_nlink(inode);
 	if (S_ISDIR(inode->i_mode)) {
 		drop_nlink(dir);
@@ -1239,6 +1247,7 @@ static int scoutfs_symlink(KC_VFS_NS_DEF
 	struct scoutfs_lock *dir_lock = NULL;
 	struct scoutfs_lock *inode_lock = NULL;
 	struct scoutfs_inode_info *si;
+	struct kc_timespec cur_time;
 	LIST_HEAD(ind_locks);
 	u64 hash;
 	u64 pos;
@@ -1278,11 +1287,13 @@ static int scoutfs_symlink(KC_VFS_NS_DEF
 	set_dentry_fsdata(dentry, dir_lock);
 
 	i_size_write(dir, i_size_read(dir) + dentry->d_name.len);
-	dir->i_mtime = dir->i_ctime = current_time(inode);
+	cur_time = current_time(inode);
+	inode_set_mtime_to_ts(dir, cur_time);
+	inode_set_ctime_to_ts(dir, cur_time);
 	inode_inc_iversion(dir);
 
-	inode->i_ctime = dir->i_mtime;
-	si->crtime = inode->i_ctime;
+	inode_set_ctime_to_ts(inode, inode_get_mtime(dir));
+	si->crtime = inode_get_ctime(inode);
 	i_size_write(inode, name_len);
 	inode_inc_iversion(inode);
 	scoutfs_forest_inc_inode_count(sb);
@@ -1804,15 +1815,15 @@ static int scoutfs_rename_common(KC_VFS_NS_DEF
 	}
 
 	now = current_time(old_inode);
-	old_dir->i_ctime = now;
-	old_dir->i_mtime = now;
+	inode_set_ctime_to_ts(old_dir, now);
+	inode_set_mtime_to_ts(old_dir, now);
 	if (new_dir != old_dir) {
-		new_dir->i_ctime = now;
-		new_dir->i_mtime = now;
+		inode_set_ctime_to_ts(new_dir, now);
+		inode_set_mtime_to_ts(new_dir, now);
 	}
-	old_inode->i_ctime = now;
+	inode_set_ctime_to_ts(old_inode, now);
 	if (new_inode)
-		new_inode->i_ctime = now;
+		inode_set_ctime_to_ts(new_inode, now);
 
 	inode_inc_iversion(old_dir);
 	inode_inc_iversion(old_inode);
@@ -1939,6 +1950,7 @@ static int scoutfs_tmpfile(KC_VFS_NS_DEF
 	struct scoutfs_lock *inode_lock = NULL;
 	struct scoutfs_lock *orph_lock = NULL;
 	struct scoutfs_inode_info *si;
+	struct kc_timespec cur_time;
 	LIST_HEAD(ind_locks);
 	int ret;
 
@@ -1955,8 +1967,11 @@ static int scoutfs_tmpfile(KC_VFS_NS_DEF
 	if (ret < 0)
 		goto out; /* XXX returning error but items created */
 
-	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
-	si->crtime = inode->i_mtime;
+	cur_time = current_time(inode);
+	inode_set_mtime_to_ts(inode, cur_time);
+	inode_set_ctime_to_ts(inode, cur_time);
+	inode_set_atime_to_ts(inode, cur_time);
+	si->crtime = inode_get_mtime(inode);
 	insert_inode_hash(inode);
 	ihold(inode); /* need to update inode modifications in d_tmpfile */
 #ifdef KC_D_TMPFILE_DENTRY
@@ -2024,7 +2039,11 @@ const struct inode_operations scoutfs_symlink_iops = {
 };
 
 const struct file_operations scoutfs_dir_fops = {
+#ifdef KC_HAVE_ITERATE_SHARED
+	.iterate_shared	= scoutfs_readdir,
+#else
 	.iterate	= scoutfs_readdir,
+#endif
 #ifdef KC_FMODE_KABI_ITERATE
 	.open		= scoutfs_dir_open,
 #endif
diff --git a/kmod/src/fence.c b/kmod/src/fence.c
index 3669dc2d..4139da8b 100644
--- a/kmod/src/fence.c
+++ b/kmod/src/fence.c
@@ -217,6 +217,9 @@ static struct attribute *fence_attrs[] = {
 	SCOUTFS_ATTR_PTR(rid),
 	NULL,
 };
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+ATTRIBUTE_GROUPS(fence);
+#endif
 
 #define FENCE_TIMEOUT_MS (MSEC_PER_SEC * 30)
 
@@ -255,7 +258,8 @@ int scoutfs_fence_start(struct super_block *sb, u64 rid, __be32 ipv4_addr, int r
 	fence->rid = rid;
 
 	ret = scoutfs_sysfs_create_attrs_parent(sb, &fi->kset->kobj,
-						&fence->ssa, fence_attrs,
+						&fence->ssa,
+						KC_KOBJ_DEFAULT(fence),
 						"%016llx", rid);
 	if (ret < 0) {
 		kfree(fence);
diff --git a/kmod/src/inode.c b/kmod/src/inode.c
index a4d118f1..5f853fab 100644
--- a/kmod/src/inode.c
+++ b/kmod/src/inode.c
@@ -275,12 +275,9 @@ static void load_inode(struct inode *inode, struct scoutfs_inode *cinode, int in
 	i_gid_write(inode, le32_to_cpu(cinode->gid));
 	inode->i_mode = le32_to_cpu(cinode->mode);
 	inode->i_rdev = le32_to_cpu(cinode->rdev);
-	inode->i_atime.tv_sec = le64_to_cpu(cinode->atime.sec);
-	inode->i_atime.tv_nsec = le32_to_cpu(cinode->atime.nsec);
-	inode->i_mtime.tv_sec = le64_to_cpu(cinode->mtime.sec);
-	inode->i_mtime.tv_nsec = le32_to_cpu(cinode->mtime.nsec);
-	inode->i_ctime.tv_sec = le64_to_cpu(cinode->ctime.sec);
-	inode->i_ctime.tv_nsec = le32_to_cpu(cinode->ctime.nsec);
+	inode_set_atime(inode, le64_to_cpu(cinode->atime.sec), le32_to_cpu(cinode->atime.nsec));
+	inode_set_mtime(inode, le64_to_cpu(cinode->mtime.sec), le32_to_cpu(cinode->mtime.nsec));
+	inode_set_ctime(inode, le64_to_cpu(cinode->ctime.sec), le32_to_cpu(cinode->ctime.nsec));
 
 	si->meta_seq = le64_to_cpu(cinode->meta_seq);
 	si->data_seq = le64_to_cpu(cinode->data_seq);
@@ -401,6 +398,7 @@ int scoutfs_getattr(KC_VFS_NS_DEF
 				 SCOUTFS_LKF_REFRESH_INODE, inode, &lock);
 	if (ret == 0) {
 		generic_fillattr(KC_VFS_INIT_NS
+				 KC_FILLATTR_REQUEST_MASK
 				 inode, stat);
 		scoutfs_unlock(sb, lock, SCOUTFS_LOCK_READ);
 	}
@@ -412,6 +410,7 @@ static int set_inode_size(struct inode *inode, struct scoutfs_lock *lock,
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 	struct super_block *sb = inode->i_sb;
+	struct kc_timespec cur_time;
 	SCOUTFS_DECLARE_PER_TASK_ENTRY(pt_ent);
 	LIST_HEAD(ind_locks);
 	int ret;
@@ -434,7 +433,9 @@ static int set_inode_size(struct inode *inode, struct scoutfs_lock *lock,
 		scoutfs_inode_inc_data_version(inode);
 
 	truncate_setsize(inode, new_size);
-	inode->i_ctime = inode->i_mtime = current_time(inode);
+	cur_time = current_time(inode);
+	inode_set_ctime_to_ts(inode, cur_time);
+	inode_set_mtime_to_ts(inode, cur_time);
 	if (truncate)
 		si->flags |= SCOUTFS_INO_FLAG_TRUNCATE;
 	scoutfs_inode_set_data_seq(inode);
@@ -901,14 +902,14 @@ static void store_inode(struct scoutfs_inode *cinode, struct inode *inode, int i
 	cinode->gid = cpu_to_le32(i_gid_read(inode));
 	cinode->mode = cpu_to_le32(inode->i_mode);
 	cinode->rdev = cpu_to_le32(inode->i_rdev);
-	cinode->atime.sec = cpu_to_le64(inode->i_atime.tv_sec);
-	cinode->atime.nsec = cpu_to_le32(inode->i_atime.tv_nsec);
+	cinode->atime.sec = cpu_to_le64(inode_get_atime_sec(inode));
+	cinode->atime.nsec = cpu_to_le32(inode_get_atime_nsec(inode));
 	memset(cinode->atime.__pad, 0, sizeof(cinode->atime.__pad));
-	cinode->ctime.sec = cpu_to_le64(inode->i_ctime.tv_sec);
-	cinode->ctime.nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+	cinode->ctime.sec = cpu_to_le64(inode_get_ctime_sec(inode));
+	cinode->ctime.nsec = cpu_to_le32(inode_get_ctime_nsec(inode));
 	memset(cinode->ctime.__pad, 0, sizeof(cinode->ctime.__pad));
-	cinode->mtime.sec = cpu_to_le64(inode->i_mtime.tv_sec);
-	cinode->mtime.nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
+	cinode->mtime.sec = cpu_to_le64(inode_get_mtime_sec(inode));
+	cinode->mtime.nsec = cpu_to_le32(inode_get_mtime_nsec(inode));
 	memset(cinode->mtime.__pad, 0, sizeof(cinode->mtime.__pad));
 
 	cinode->meta_seq = cpu_to_le64(scoutfs_inode_meta_seq(inode));
@@ -1566,6 +1567,7 @@ int scoutfs_new_inode(struct super_block *sb, struct inode *dir, umode_t mode, d
 	struct scoutfs_inode sinode;
 	struct scoutfs_key key;
 	struct inode *inode;
+	struct kc_timespec cur_time;
 	int inode_bytes;
 	int ret;
 
@@ -1595,7 +1597,10 @@ int scoutfs_new_inode(struct super_block *sb, struct inode *dir, umode_t mode, d
 	inode_init_owner(KC_VFS_INIT_NS
 			 inode, dir, mode);
 	inode_set_bytes(inode, 0);
-	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
+	cur_time = current_time(inode);
+	inode_set_mtime_to_ts(inode, cur_time);
+	inode_set_atime_to_ts(inode, cur_time);
+	inode_set_ctime_to_ts(inode, cur_time);
 	inode->i_rdev = rdev;
 	set_inode_ops(inode);
 
@@ -2068,7 +2073,7 @@ void scoutfs_inode_schedule_orphan_dwork(struct super_block *sb)
 
 		low = (opts.orphan_scan_delay_ms * 80) / 100;
 		high = (opts.orphan_scan_delay_ms * 120) / 100;
-		delay = msecs_to_jiffies(low + prandom_u32_max(high - low)) ?: 1;
+		delay = msecs_to_jiffies(low + get_random_u32_below(high - low)) ?: 1;
 
 		mod_delayed_work(system_wq, &inf->orphan_scan_dwork, delay);
 	}
diff --git a/kmod/src/item.c b/kmod/src/item.c
index e0047be4..d6fca8b0 100644
--- a/kmod/src/item.c
+++ b/kmod/src/item.c
@@ -146,7 +146,7 @@ struct cached_item {
 	unsigned int val_len;
 	struct scoutfs_key key;
 	u64 seq;
-	char val[0];
+	char val[];
 };
 
 #define CACHED_ITEM_ALIGN 8
@@ -424,7 +424,7 @@ static struct cached_item *alloc_item(struct cached_page *pg,
 	item->seq = seq;
 
 	if (val_len)
-		memcpy(item->val, val, val_len);
+		memcpy(&item->val[0], val, val_len);
 
 	update_pg_max_seq(pg, item);
 
@@ -1999,7 +1999,7 @@ int scoutfs_item_update(struct super_block *sb, struct scoutfs_key *key,
 
 	if (val_len <= found->val_len) {
 		if (val_len)
-			memcpy(found->val, val, val_len);
+			memcpy(&found->val[0], val, val_len);
 		if (val_len < found->val_len)
 			pg->erased_bytes += item_val_bytes(found->val_len) -
 					    item_val_bytes(val_len);
@@ -2316,7 +2316,7 @@ int scoutfs_item_write_dirty(struct super_block *sb)
 			lst->seq = item->seq;
 			lst->flags = item->deletion ? SCOUTFS_ITEM_FLAG_DELETION : 0;
 			lst->val_len = item->val_len;
-			memcpy(lst->val, item->val, item->val_len);
+			memcpy(&lst->val[0], item->val, item->val_len);
 		}
 
 		spin_lock(&cinf->dirty_lock);
@@ -2626,10 +2626,10 @@ int scoutfs_item_setup(struct super_block *sb)
 
 	for_each_possible_cpu(cpu)
 		init_pcpu_pages(cinf, cpu);
-
-	KC_INIT_SHRINKER_FUNCS(&cinf->shrinker, item_cache_count_objects,
-			       item_cache_scan_objects);
-	KC_REGISTER_SHRINKER(&cinf->shrinker, "scoutfs-item:" SCSBF, SCSB_ARGS(sb));
+	KC_SETUP_SHRINKER(cinf->shrinker, cinf, 0, item_cache_count_objects,
+			  item_cache_scan_objects, "scoutfs-item:" SCSBF, SCSB_ARGS(sb));
+	if (KC_SHRINKER_IS_NULL(cinf->shrinker))
+		return -ENOMEM;
 #ifdef KC_CPU_NOTIFIER
         cinf->notifier.notifier_call = item_cpu_callback;
         register_hotcpu_notifier(&cinf->notifier);
@@ -2654,7 +2654,7 @@ void scoutfs_item_destroy(struct super_block *sb)
 #ifdef KC_CPU_NOTIFIER
 		unregister_hotcpu_notifier(&cinf->notifier);
 #endif
-		KC_UNREGISTER_SHRINKER(&cinf->shrinker);
+		KC_UNREGISTER_SHRINKER(cinf->shrinker);
 
 		for_each_possible_cpu(cpu)
 			drop_pcpu_pages(sb, cinf, cpu);
diff --git a/kmod/src/kernelcompat.c b/kmod/src/kernelcompat.c
index 2463d134..fc5e895c 100644
--- a/kmod/src/kernelcompat.c
+++ b/kmod/src/kernelcompat.c
@@ -147,3 +147,13 @@ unsigned long kc_list_lru_shrink_walk(struct list_lru *lru, struct shrink_contro
 }
 
 #endif
+
+#ifndef KC_FS_INODE_C_TIME_ACCESSOR
+struct timespec64 inode_set_ctime_current(struct inode *inode)
+{
+	struct timespec64 now = current_time(inode);
+
+	inode_set_ctime(inode, now.tv_sec, now.tv_nsec);
+	return now;
+}
+#endif
diff --git a/kmod/src/kernelcompat.h b/kmod/src/kernelcompat.h
index 5564a12a..3d2db22d 100644
--- a/kmod/src/kernelcompat.h
+++ b/kmod/src/kernelcompat.h
@@ -142,25 +142,54 @@ struct timespec64 kc_current_time(struct inode *inode);
 #define kc_timespec timespec64
 #endif
 
-#ifndef KC_SHRINKER_SHRINK
-
-#define KC_DEFINE_SHRINKER(name) struct shrinker name
-#define KC_INIT_SHRINKER_FUNCS(name, countfn, scanfn) do {	\
-	__typeof__(name) _shrink = (name);			\
-	_shrink->count_objects = (countfn);			\
-	_shrink->scan_objects = (scanfn);			\
-	_shrink->seeks = DEFAULT_SEEKS;			\
+#ifdef KC_SHRINKER_ALLOC
+// el10+
+
+#define KC_DEFINE_SHRINKER(name) struct shrinker *(name)
+#define KC_SHRINKER_CONTAINER_OF(ptr, type) ptr->private_data
+#define KC_SETUP_SHRINKER(ptr, priv, flags, countfn, scanfn, fmt, args)	\
+do {								\
+	ptr = shrinker_alloc(flags, fmt, args);			\
+	if (ptr) {						\
+		ptr->private_data = (priv);			\
+		ptr->seeks = DEFAULT_SEEKS;			\
+		ptr->count_objects = countfn;			\
+		ptr->scan_objects = scanfn;			\
+		shrinker_register(ptr);				\
+	}							\
 } while (0)
+#define KC_UNREGISTER_SHRINKER(ptr) shrinker_free(ptr)
+#define KC_SHRINKER_FN(ptr) (ptr)
+#define KC_SHRINKER_IS_NULL(ptr) (!(ptr))
+
+#else /* KC_SHRINKER_ALLOC */
+#ifndef KC_SHRINKER_SHRINK
+// el9, el8
 
+#define KC_DEFINE_SHRINKER(name) struct shrinker (name)
 #define KC_SHRINKER_CONTAINER_OF(ptr, type) container_of(ptr, type, shrinker)
 #ifdef KC_SHRINKER_NAME
-#define KC_REGISTER_SHRINKER register_shrinker
+#define KC_SETUP_SHRINKER(ptr, priv, flags, countfn, scanfn, fmt, args)	\
+do {								\
+	(ptr).count_objects = (countfn);			\
+	(ptr).scan_objects = (scanfn);				\
+	(ptr).seeks = DEFAULT_SEEKS;				\
+	register_shrinker(&(ptr), fmt, args);			\
+} while (0)
 #else
-#define KC_REGISTER_SHRINKER(ptr, fmt, ...) (register_shrinker(ptr))
+#define KC_SETUP_SHRINKER(ptr, priv, flags, countfn, scanfn, fmt, args)	\
+do {								\
+	(ptr).count_objects = (countfn);			\
+	(ptr).scan_objects = (scanfn);				\
+	(ptr).seeks = DEFAULT_SEEKS;				\
+	register_shrinker(&(ptr));				\
+} while (0)
 #endif /* KC_SHRINKER_NAME */
-#define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(ptr))
-#define KC_SHRINKER_FN(ptr) (ptr)
-#else
+#define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(&(ptr)))
+#define KC_SHRINKER_FN(ptr) (&ptr)
+
+#else /* KC_SHRINKER_SHRINK */
+// el7
 
 #include <linux/shrinker.h>
 #ifndef SHRINK_STOP
@@ -176,19 +205,21 @@ struct kc_shrinker_wrapper {
 };
 
 #define KC_DEFINE_SHRINKER(name) struct kc_shrinker_wrapper name;
-#define KC_INIT_SHRINKER_FUNCS(name, countfn, scanfn) do {	\
-	struct kc_shrinker_wrapper *_wrap = (name);		\
-	_wrap->count_objects = (countfn);			\
-	_wrap->scan_objects = (scanfn);				\
-	_wrap->shrink.shrink = kc_shrink_wrapper_fn;		\
-	_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, fmt, ...) (register_shrinker(ptr.shrink))
-#define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(ptr.shrink))
-#define KC_SHRINKER_FN(ptr) (ptr.shrink)
+#define KC_SETUP_SHRINKER(ptr, priv, flags, countfn, scanfn, fmt, args)	\
+do {								\
+	(ptr).count_objects = (countfn);			\
+	(ptr).scan_objects = (scanfn);				\
+	(ptr).shrink.shrink = kc_shrink_wrapper_fn;		\
+	(ptr).shrink.seeks = DEFAULT_SEEKS;			\
+	register_shrinker(&(ptr).shrink);			\
+} while (0)
+#define KC_UNREGISTER_SHRINKER(ptr) (unregister_shrinker(&(ptr).shrink))
+#define KC_SHRINKER_FN(ptr) (&(ptr).shrink)
 
 #endif /* KC_SHRINKER_SHRINK */
+#define KC_SHRINKER_IS_NULL(ptr) (0)
+#endif /* KC_SHRINKER_ALLOC */
 
 #ifdef KC_KERNEL_GETSOCKNAME_ADDRLEN
 #include <linux/net.h>
@@ -279,6 +310,12 @@ typedef unsigned int blk_opf_t;
 #endif
 #endif /* KC_VFS_METHOD_MNT_IDMAP_ARG */
 
+#ifdef KC_GENERIC_FILLATTR_REQUEST_MASK
+#define KC_FILLATTR_REQUEST_MASK request_mask,
+#else
+#define KC_FILLATTR_REQUEST_MASK
+#endif
+
 #ifdef KC_BIO_ALLOC_DEV_OPF_ARGS
 #define kc_bio_alloc bio_alloc
 #else
@@ -452,6 +489,7 @@ unsigned long kc_list_lru_shrink_walk(struct list_lru *lru, struct shrink_contro
 				      kc_list_lru_walk_cb_t isolate, void *cb_arg);
 #else
 #define kc_list_lru_shrink_walk list_lru_shrink_walk
+#define kc_list_lru_walk list_lru_walk
 #endif
 
 #if defined(KC_LIST_LRU_WALK_CB_ITEM_LOCK)
@@ -489,4 +527,133 @@ static inline void stack_trace_print(unsigned long *entries, unsigned int nr_ent
 }
 #endif
 
+#ifndef KC_HAVE_GET_RANDOM_U32_BELOW
+#define get_random_u32_below prandom_u32_max
+#endif
+
+#ifndef KC_FS_INODE_C_TIME_ACCESSOR
+struct timespec64 inode_set_ctime_current(struct inode *inode);
+static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode,
+						      struct timespec64 ts)
+{
+	inode->i_ctime.tv_sec = ts.tv_sec;
+	inode->i_ctime.tv_nsec = ts.tv_nsec;
+	return ts;
+}
+
+static inline struct timespec64 inode_set_ctime(struct inode *inode,
+						time64_t sec, long nsec)
+{
+	struct timespec64 ts = { .tv_sec  = sec,
+				 .tv_nsec = nsec };
+
+	return inode_set_ctime_to_ts(inode, ts);
+}
+
+static inline struct timespec64 inode_get_ctime(const struct inode *inode)
+{
+	struct timespec64 ts = { .tv_sec  = inode->i_ctime.tv_sec,
+				 .tv_nsec = inode->i_ctime.tv_nsec };
+	return ts;
+}
+#endif
+
+#ifndef KC_FS_INODE_AM_TIME_ACCESSOR
+static inline struct timespec64 inode_get_mtime(const struct inode *inode)
+{
+	struct timespec64 ts = { .tv_sec  = inode->i_mtime.tv_sec,
+				 .tv_nsec = inode->i_mtime.tv_nsec };
+	return ts;
+}
+
+static inline struct timespec64 inode_set_mtime_to_ts(struct inode *inode,
+						      struct timespec64 ts)
+{
+	inode->i_mtime.tv_sec = ts.tv_sec;
+	inode->i_mtime.tv_nsec = ts.tv_nsec;
+	return ts;
+}
+
+static inline struct timespec64 inode_set_mtime(struct inode *inode,
+						time64_t sec, long nsec)
+{
+	struct timespec64 ts = { .tv_sec  = sec,
+				 .tv_nsec = nsec };
+
+	return inode_set_mtime_to_ts(inode, ts);
+}
+
+static inline struct timespec64 inode_set_atime_to_ts(struct inode *inode,
+						      struct timespec64 ts)
+{
+	inode->i_atime.tv_sec = ts.tv_sec;
+	inode->i_atime.tv_nsec = ts.tv_nsec;
+	return ts;
+}
+
+static inline struct timespec64 inode_set_atime(struct inode *inode,
+						time64_t sec, long nsec)
+{
+	struct timespec64 ts = { .tv_sec  = sec,
+				 .tv_nsec = nsec };
+
+	return inode_set_atime_to_ts(inode, ts);
+}
+
+static inline time64_t inode_get_ctime_sec(const struct inode *inode)
+{
+	return inode->i_ctime.tv_sec;
+}
+static inline long inode_get_ctime_nsec(const struct inode *inode)
+{
+	return inode->i_ctime.tv_nsec;
+}
+static inline time64_t inode_get_mtime_sec(const struct inode *inode)
+{
+	return inode->i_mtime.tv_sec;
+}
+static inline long inode_get_mtime_nsec(const struct inode *inode)
+{
+	return inode->i_mtime.tv_nsec;
+}
+static inline time64_t inode_get_atime_sec(const struct inode *inode)
+{
+	return inode->i_atime.tv_sec;
+}
+static inline long inode_get_atime_nsec(const struct inode *inode)
+{
+	return inode->i_atime.tv_nsec;
+}
+#endif
+
+#ifdef KC_HAVE_BD_INODE
+#define KC_BDEV_INODE(b) (b)->bd_inode
+#define KC_BDEV_MAPPING(b) (b)->bd_inode->i_mapping
+#else
+#define KC_BDEV_INODE(b) (b)->bd_mapping->host
+#define KC_BDEV_MAPPING(b) (b)->bd_mapping
+#endif
+
+#ifdef KC_HAVE_ASSIGN_STR_PARMS
+#define kc__assign_str(a, b) __assign_str(a, b)
+#else
+#define kc__assign_str(a, b) __assign_str(a)
+#endif
+
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+#define KC_KOBJ_DEFAULT_OP default_groups
+#define KC_KOBJ_DEFAULT(name) (name##_groups)
+#define KC_KOBJ_DEFAULT_PICK(group, attrs) (group)
+#else
+#define KC_KOBJ_DEFAULT_OP default_attrs
+#define KC_KOBJ_DEFAULT(name) (name##_attrs)
+#define KC_KOBJ_DEFAULT_PICK(group, attrs) (attrs)
+#endif
+
+#ifdef KC_BLOCK_WRITE_BEGIN_FOLIO
+#define KC_PAGE_OR_FOLIO(p, f) f
+#else
+#define KC_PAGE_OR_FOLIO(p, f) p
+#endif
+
 #endif
diff --git a/kmod/src/options.c b/kmod/src/options.c
index b7565d76..6812a7db 100644
--- a/kmod/src/options.c
+++ b/kmod/src/options.c
@@ -752,13 +752,18 @@ static struct attribute *options_attrs[] = {
 	SCOUTFS_ATTR_PTR(quorum_slot_nr),
 	NULL,
 };
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+ATTRIBUTE_GROUPS(options);
+#endif
 
 int scoutfs_options_setup(struct super_block *sb)
 {
 	DECLARE_OPTIONS_INFO(sb, optinf);
 	int ret;
 
-	ret = scoutfs_sysfs_create_attrs(sb, &optinf->sysfs_attrs, options_attrs, "mount_options");
+	ret = scoutfs_sysfs_create_attrs(sb, &optinf->sysfs_attrs,
+					 KC_KOBJ_DEFAULT_PICK(options_groups, options_attrs),
+					 "mount_options");
 	if (ret < 0)
 		scoutfs_options_destroy(sb);
 	return ret;
diff --git a/kmod/src/quorum.c b/kmod/src/quorum.c
index 242804ed..24be890b 100644
--- a/kmod/src/quorum.c
+++ b/kmod/src/quorum.c
@@ -162,7 +162,7 @@ static void quorum_slot_sin(struct scoutfs_quorum_config *qconf, int i, struct s
 static ktime_t election_timeout(void)
 {
 	return ktime_add_ms(ktime_get(), SCOUTFS_QUORUM_ELECT_MIN_MS +
-				 prandom_u32_max(SCOUTFS_QUORUM_ELECT_VAR_MS));
+				 get_random_u32_below(SCOUTFS_QUORUM_ELECT_VAR_MS));
 }
 
 static ktime_t heartbeat_interval(void)
@@ -1192,6 +1192,9 @@ static struct attribute *quorum_attrs[] = {
 	SCOUTFS_ATTR_PTR(is_leader),
 	NULL,
 };
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+ATTRIBUTE_GROUPS(quorum);
+#endif
 
 static inline bool valid_ipv4_unicast(__be32 addr)
 {
@@ -1352,7 +1355,7 @@ int scoutfs_quorum_setup(struct super_block *sb)
 	if (ret < 0)
 		goto out;
 
-	ret = scoutfs_sysfs_create_attrs(sb, &qinf->ssa, quorum_attrs,
+	ret = scoutfs_sysfs_create_attrs(sb, &qinf->ssa, KC_KOBJ_DEFAULT(quorum),
 					 "quorum");
 	if (ret < 0)
 		goto out;
diff --git a/kmod/src/quota.c b/kmod/src/quota.c
index 3163ee8c..96d82981 100644
--- a/kmod/src/quota.c
+++ b/kmod/src/quota.c
@@ -204,7 +204,7 @@ static struct squota_check *lookup_random_check(struct rhashtable *rht)
 
 	tbl = rht_dereference_rcu(rht->tbl, rht);
 	do {
-		for (s = 0, i = prandom_u32_max(tbl->size);
+		for (s = 0, i = get_random_u32_below(tbl->size);
 		     s < tbl->size;
 		     s++, i = (i + 1) % tbl->size) {
 			rht_for_each_entry_rcu(chk, pos, tbl, i, head) {
@@ -269,7 +269,7 @@ static void shrink_all_cached_checks(struct squota_info *qtinf)
 {
 	struct shrink_control sc = { .nr_to_scan = LONG_MAX, };
 
-	scan_cached_checks(KC_SHRINKER_FN(&qtinf->shrinker), &sc);
+	scan_cached_checks(KC_SHRINKER_FN(qtinf->shrinker), &sc);
 }
 
 static u8 ns_is_attr(u8 ns)
@@ -1225,8 +1225,12 @@ int scoutfs_quota_setup(struct super_block *sb)
 	spin_lock_init(&qtinf->lock);
 	init_waitqueue_head(&qtinf->waitq);
 
-	KC_INIT_SHRINKER_FUNCS(&qtinf->shrinker, count_cached_checks, scan_cached_checks);
-	KC_REGISTER_SHRINKER(&qtinf->shrinker, "scoutfs-quota:" SCSBF, SCSB_ARGS(sb));
+	KC_SETUP_SHRINKER(qtinf->shrinker, qtinf, 0, count_cached_checks,
+			  scan_cached_checks, "scoutfs-quota:" SCSBF, SCSB_ARGS(sb));
+	if (KC_SHRINKER_IS_NULL(qtinf->shrinker)) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	sbi->squota_info = qtinf;
 
@@ -1250,7 +1254,7 @@ void scoutfs_quota_destroy(struct super_block *sb)
 
 	if (qtinf) {
 		debugfs_remove(qtinf->drop_dentry);
-		KC_UNREGISTER_SHRINKER(&qtinf->shrinker);
+		KC_UNREGISTER_SHRINKER(qtinf->shrinker);
 
 		spin_lock(&qtinf->lock);
 		rs = rcu_dereference_protected(qtinf->ruleset, lockdep_is_held(&qtinf->lock));
diff --git a/kmod/src/scoutfs_trace.h b/kmod/src/scoutfs_trace.h
index c7157352..25279980 100644
--- a/kmod/src/scoutfs_trace.h
+++ b/kmod/src/scoutfs_trace.h
@@ -102,7 +102,7 @@ TRACE_EVENT(scoutfs_setattr,
 		SCSB_TRACE_ASSIGN(dentry->d_inode->i_sb);
 		__entry->ino = scoutfs_ino(dentry->d_inode);
 		__entry->d_len = dentry->d_name.len;
-		__assign_str(d_name, dentry->d_name.name);
+		kc__assign_str(d_name, dentry->d_name.name);
 		__entry->ia_valid = attr->ia_valid;
 		__entry->size_change = !!(attr->ia_valid & ATTR_SIZE);
 		__entry->ia_size = attr->ia_size;
@@ -1638,9 +1638,9 @@ TRACE_EVENT(scoutfs_rename,
 	TP_fast_assign(
 		SCSB_TRACE_ASSIGN(sb);
 		__entry->old_dir_ino = scoutfs_ino(old_dir);
-		__assign_str(old_name, old_dentry->d_name.name)
+		kc__assign_str(old_name, old_dentry->d_name.name);
 		__entry->new_dir_ino = scoutfs_ino(new_dir);
-		__assign_str(new_name, new_dentry->d_name.name)
+		kc__assign_str(new_name, new_dentry->d_name.name);
 		__entry->new_inode_ino = new_dentry->d_inode ?
 					 scoutfs_ino(new_dentry->d_inode) : 0;
 	),
@@ -1670,7 +1670,7 @@ TRACE_EVENT(scoutfs_d_revalidate,
 	TP_fast_assign(
 		SCSB_TRACE_ASSIGN(sb);
 		__entry->dentry = dentry;
-		__assign_str(name, dentry->d_name.name)
+		kc__assign_str(name, dentry->d_name.name);
 		__entry->ino = dentry->d_inode ? scoutfs_ino(dentry->d_inode) : 0;
 		__entry->dir_ino = dir_ino;
 		__entry->flags = flags;
@@ -1705,7 +1705,7 @@ TRACE_EVENT(scoutfs_validate_dentry,
 		SCSB_TRACE_ASSIGN(sb);
 		__entry->dentry = dentry;
 		__entry->dir_ino = dir_ino;
-		__assign_str(name, dentry->d_name.name)
+		kc__assign_str(name, dentry->d_name.name);
 		__entry->dentry_ino = dentry_ino;
 		__entry->dent_ino = dent_ino;
 		__entry->fsdata_gen = (unsigned long long)dentry->d_fsdata;
@@ -1827,7 +1827,7 @@ TRACE_EVENT(scoutfs_get_name,
 		SCSB_TRACE_ASSIGN(sb);
 		__entry->parent_ino = scoutfs_ino(parent);
 		__entry->child_ino = scoutfs_ino(child);
-		__assign_str(name, name);
+		kc__assign_str(name, name);
 	),
 
 	TP_printk(SCSBF" parent %llu child %llu name: %s",
diff --git a/kmod/src/server.c b/kmod/src/server.c
index 7f979df7..7df99560 100644
--- a/kmod/src/server.c
+++ b/kmod/src/server.c
@@ -20,7 +20,6 @@
 #include <net/sock.h>
 #include <net/tcp.h>
 #include <linux/log2.h>
-#include <asm/unaligned.h>
 
 #include "format.h"
 #include "counters.h"
@@ -3372,7 +3371,7 @@ static int server_clear_volopt(struct super_block *sb, struct scoutfs_net_connec
 
 static u64 device_blocks(struct block_device *bdev, int shift)
 {
-	return i_size_read(bdev->bd_inode) >> shift;
+	return i_size_read(KC_BDEV_INODE(bdev)) >> shift;
 }
 
 static int server_resize_devices(struct super_block *sb, struct scoutfs_net_connection *conn,
diff --git a/kmod/src/srch.c b/kmod/src/srch.c
index e1b5fb90..efd72061 100644
--- a/kmod/src/srch.c
+++ b/kmod/src/srch.c
@@ -18,7 +18,11 @@
 #include <linux/pagemap.h>
 #include <linux/vmalloc.h>
 #include <linux/sort.h>
+#ifdef KC_HAVE__LINUX_UNALIGNED_H
+#include <linux/unaligned.h>
+#else
 #include <asm/unaligned.h>
+#endif
 
 #include "super.h"
 #include "format.h"
@@ -2346,6 +2350,9 @@ static struct attribute *srch_attrs[] = {
 	SCOUTFS_ATTR_PTR(compact_delay_ms),
 	NULL,
 };
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+ATTRIBUTE_GROUPS(srch);
+#endif
 
 void scoutfs_srch_destroy(struct super_block *sb)
 {
@@ -2387,7 +2394,8 @@ int scoutfs_srch_setup(struct super_block *sb)
 
 	sbi->srch_info = srinf;
 
-	ret = scoutfs_sysfs_create_attrs(sb, &srinf->ssa, srch_attrs, "srch");
+	ret = scoutfs_sysfs_create_attrs(sb, &srinf->ssa, KC_KOBJ_DEFAULT(srch),
+					 "srch");
 	if (ret < 0)
 		goto out;
 
diff --git a/kmod/src/super.c b/kmod/src/super.c
index 3c837160..a6739963 100644
--- a/kmod/src/super.c
+++ b/kmod/src/super.c
@@ -283,7 +283,7 @@ int scoutfs_write_super(struct super_block *sb,
 static bool small_bdev(struct super_block *sb, char *which, u64 blocks,
 		       struct block_device *bdev, int shift)
 {
-	u64 size = (u64)i_size_read(bdev->bd_inode);
+	u64 size = (u64)i_size_read(KC_BDEV_INODE(bdev));
 	u64 count = size >> shift;
 
 	if (blocks > count) {
@@ -508,7 +508,7 @@ static int scoutfs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 
 	/* btree blocks use long lived bh->b_data refs */
-	mapping_set_gfp_mask(sb->s_bdev->bd_inode->i_mapping, GFP_NOFS);
+	mapping_set_gfp_mask(KC_BDEV_MAPPING(sb->s_bdev), GFP_NOFS);
 
 	sbi = kzalloc(sizeof(struct scoutfs_sb_info), GFP_KERNEL);
 	sb->s_fs_info = sbi;
@@ -552,6 +552,7 @@ static int scoutfs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	sbi->meta_bdev_file = meta_bdev_file;
 	sbi->meta_bdev = file_bdev(meta_bdev_file);
+
 #else
 #ifdef KC_BLKDEV_PUT_HOLDER_ARG
 	meta_bdev = blkdev_get_by_path(opts.metadev_path, SCOUTFS_META_BDEV_MODE, sb, NULL);
@@ -567,7 +568,11 @@ static int scoutfs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->meta_bdev = meta_bdev;
 #endif
 
+#ifdef KC_BLKDEV_SET_BLOCKSIZE_FILE
+	ret = set_blocksize(sbi->meta_bdev_file, SCOUTFS_BLOCK_SM_SIZE);
+#else
 	ret = set_blocksize(sbi->meta_bdev, SCOUTFS_BLOCK_SM_SIZE);
+#endif
 	if (ret != 0) {
 		scoutfs_err(sb, "failed to set metadev blocksize, returned %d",
 			    ret);
diff --git a/kmod/src/sysfs.c b/kmod/src/sysfs.c
index b3c7ddbf..3b7e176f 100644
--- a/kmod/src/sysfs.c
+++ b/kmod/src/sysfs.c
@@ -103,12 +103,11 @@ static ssize_t attr_funcs_show(struct kobject *kobj, struct attribute *attr,
 	};								\
 									\
 	static struct kobj_type _name##_ktype = {			\
-		.default_attrs  = _name##_attrs,			\
+		.KC_KOBJ_DEFAULT_OP = KC_KOBJ_DEFAULT(_name),		\
 		.sysfs_ops      = &_name##_sysfs_ops,			\
 		.release        = _name##_release,			\
 	};
 
-
 static struct attribute *sb_id_attrs[] = {
 	&data_device_maj_min_attr_funcs.attr,
 	&format_version_attr_funcs.attr,
@@ -116,6 +115,9 @@ static struct attribute *sb_id_attrs[] = {
 	&rid_attr_funcs.attr,
 	NULL,
 };
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+ATTRIBUTE_GROUPS(sb_id);
+#endif
 KTYPE(sb_id);
 
 struct kobject *scoutfs_sysfs_sb_dir(struct super_block *sb)
@@ -155,7 +157,12 @@ void scoutfs_sysfs_init_attrs(struct super_block *sb,
 int scoutfs_sysfs_create_attrs_parent(struct super_block *sb,
 				      struct kobject *parent,
 				      struct scoutfs_sysfs_attrs *ssa,
-				      struct attribute **attrs, char *fmt, ...)
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+				      const struct attribute_group **groups,
+#else
+				      struct attribute **attrs,
+#endif
+				      char *fmt, ...)
 {
 	va_list args;
 	size_t name_len;
@@ -168,7 +175,11 @@ int scoutfs_sysfs_create_attrs_parent(struct super_block *sb,
 
 	ssa->sb = sb;
 	init_completion(&ssa->comp);
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+	ssa->ktype.default_groups = groups;
+#else
 	ssa->ktype.default_attrs = attrs;
+#endif
 	ssa->ktype.sysfs_ops = &kobj_sysfs_ops;
 	ssa->ktype.release = scoutfs_sysfs_release;
 
diff --git a/kmod/src/sysfs.h b/kmod/src/sysfs.h
index 70b85af8..177e98f7 100644
--- a/kmod/src/sysfs.h
+++ b/kmod/src/sysfs.h
@@ -39,10 +39,15 @@ void scoutfs_sysfs_init_attrs(struct super_block *sb,
 int scoutfs_sysfs_create_attrs_parent(struct super_block *sb,
 				      struct kobject *parent,
 				      struct scoutfs_sysfs_attrs *ssa,
-				      struct attribute **attrs, char *fmt, ...);
-#define scoutfs_sysfs_create_attrs(sb, ssa, attrs, fmt, args...)	\
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+				      const struct attribute_group **groups,
+#else
+				      struct attribute **attrs,
+#endif
+				      char *fmt, ...);
+#define scoutfs_sysfs_create_attrs(sb, ssa, group_or_attrs, fmt, args...)	\
 	scoutfs_sysfs_create_attrs_parent(sb, scoutfs_sysfs_sb_dir(sb),	\
-					  ssa, attrs, fmt, ##args)
+					  ssa, group_or_attrs, fmt, ##args)
 
 void scoutfs_sysfs_destroy_attrs(struct super_block *sb,
 				 struct scoutfs_sysfs_attrs *ssa);
diff --git a/kmod/src/volopt.c b/kmod/src/volopt.c
index 303d94b0..b87e4ac5 100644
--- a/kmod/src/volopt.c
+++ b/kmod/src/volopt.c
@@ -52,6 +52,15 @@ static struct volopt_nr_name {
 /* initialized by setup, pointer array is null terminated */
 static struct kobj_attribute volopt_attrs[ARRAY_SIZE(volopt_table)];
 static struct attribute *volopt_attr_ptrs[ARRAY_SIZE(volopt_table) + 1];
+#ifdef KC_KOBJECT_DEFAULT_GROUPS
+static const struct attribute_group volopt_group = {
+	.attrs = volopt_attr_ptrs,
+};
+static const struct attribute_group *volopt_groups[] = {
+	&volopt_group,
+	NULL,
+};
+#endif
 
 static void get_opt_data(struct kobj_attribute *attr, struct scoutfs_volume_options *volopt,
 			 u64 *bit, __le64 **opt)
@@ -164,7 +173,9 @@ int scoutfs_volopt_setup(struct super_block *sb)
 	BUILD_BUG_ON(ARRAY_SIZE(volopt_table) != ARRAY_SIZE(volopt_attr_ptrs) - 1);
 	volopt_attr_ptrs[i] = NULL;
 
-	ret = scoutfs_sysfs_create_attrs(sb, &vinf->ssa, volopt_attr_ptrs, "volume_options");
+	ret = scoutfs_sysfs_create_attrs(sb, &vinf->ssa,
+					 KC_KOBJ_DEFAULT_PICK(volopt_groups, volopt_attr_ptrs),
+					 "volume_options");
 	if (ret < 0)
 		goto out;
 
diff --git a/kmod/src/wkic.c b/kmod/src/wkic.c
index 44eef494..e404ed9f 100644
--- a/kmod/src/wkic.c
+++ b/kmod/src/wkic.c
@@ -171,7 +171,7 @@ struct wkic_item {
 	u64 seq;
 	unsigned int val_len;
 	u8 flags;
-	u8 val[0] __aligned(ARCH_KMALLOC_MINALIGN); /* totls have native structs */
+	u8 val[] __aligned(ARCH_KMALLOC_MINALIGN); /* totls have native structs */
 };
 
 static struct wkic_item *witem_container(struct rb_node *node)
@@ -763,7 +763,7 @@ static void fill_page_items(struct super_block *sb, struct wkic_page *wpage, str
 		pg_item->val_len = witem->val_len;
 		pg_item->flags = witem->flags;
 		if (witem->val_len)
-			memcpy(pg_item->val, witem->val, witem->val_len);
+			memcpy(&pg_item->val[0], witem->val, witem->val_len);
 
 		/* always inserting greatest item into page */
 		rb_link_node(&pg_item->node, parent, node);
@@ -1112,8 +1112,13 @@ 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, "scoutfs-weak_item:" SCSBF, SCSB_ARGS(sb));
+	KC_SETUP_SHRINKER(winf->shrinker, winf, 0, wkic_shrink_count,
+			  wkic_shrink_scan, "scoutfs-weak_item:" SCSBF, SCSB_ARGS(sb));
+	if (KC_SHRINKER_IS_NULL(winf->shrinker)) {
+		debugfs_remove(winf->drop_dentry);
+		kfree(winf);
+		return -ENOMEM;
+	}
 
 	sbi->wkic_info = winf;
 	return 0;
@@ -1141,7 +1146,7 @@ void scoutfs_wkic_destroy(struct super_block *sb)
 
 	if (winf) {
 		debugfs_remove(winf->drop_dentry);
-		KC_UNREGISTER_SHRINKER(&winf->shrinker);
+		KC_UNREGISTER_SHRINKER(winf->shrinker);
 
 		/* trees are in sync so tearing down one frees all pages */
 		rbtree_postorder_for_each_entry_safe(wpage, tmp, &winf->wpage_roots[0], nodes[0]) {
diff --git a/kmod/src/xattr.c b/kmod/src/xattr.c
index 7805b364..d6235ea5 100644
--- a/kmod/src/xattr.c
+++ b/kmod/src/xattr.c
@@ -907,7 +907,7 @@ int scoutfs_xattr_set_locked(struct inode *inode, const char *name, size_t name_
 
 	/* XXX do these want i_mutex or anything? */
 	inode_inc_iversion(inode);
-	inode->i_ctime = current_time(inode);
+	inode_set_ctime_to_ts(inode, current_time(inode));
 	ret = 0;
 
 out:
diff --git a/tests/funcs/filter.sh b/tests/funcs/filter.sh
index 3dc593c8..44f965fe 100644
--- a/tests/funcs/filter.sh
+++ b/tests/funcs/filter.sh
@@ -3,7 +3,8 @@
 t_filter_fs()
 {
 	sed -e 's@mnt/test\.[0-9]*@mnt/test@g' \
-	    -e 's@Device: [a-fA-F0-9]*h/[0-9]*d@Device: 0h/0d@g'
+	    -e 's@Device: [a-fA-F0-9]*h/[0-9]*d@Device: 0h/0d@g' \
+	    -e 's@Device: [0-9]*,[0-9]*@Device: 0h/0d@g'
 }
 
 #
@@ -173,6 +174,6 @@ t_filter_dmesg()
 	# creating block devices may trigger this
 	re="$re|block device autoloading is deprecated and will be removed."
 
-	egrep -v "($re)" | \
+	grep -v -E "($re)" | \
 		ignore_harmless_unwind_kasan_stack_oob
 }
diff --git a/tests/golden/basic-posix-consistency b/tests/golden/basic-posix-consistency
index e96251bc..7fd126a1 100644
--- a/tests/golden/basic-posix-consistency
+++ b/tests/golden/basic-posix-consistency
@@ -47,7 +47,7 @@ four
 --- dir within dir
 --- overwrite file
 --- can't overwrite non-empty dir
-mv: cannot move '/mnt/test/test/basic-posix-consistency/dir/c/clobber' to '/mnt/test/test/basic-posix-consistency/dir/a/dir': Directory not empty
+mv: cannot overwrite '/mnt/test/test/basic-posix-consistency/dir/a/dir': Directory not empty
 --- can overwrite empty dir
 --- can rename into root
 == path resoluion
diff --git a/tests/run-tests.sh b/tests/run-tests.sh
index f6c506ec..e182fd1e 100755
--- a/tests/run-tests.sh
+++ b/tests/run-tests.sh
@@ -301,7 +301,7 @@ fi
 # include everything by default
 test -z "$T_INCLUDE" && T_INCLUDE="-e '.*'"
 # (quickly) exclude nothing by default
-test -z "$T_EXCLUDE" && T_EXCLUDE="-e '\Zx'"
+test -z "$T_EXCLUDE" && T_EXCLUDE="-e '^$'"
 
 # eval to strip re ticks but not expand
 tests=$(grep -v "^#" $T_SEQUENCE |
diff --git a/tests/tests/basic-posix-consistency.sh b/tests/tests/basic-posix-consistency.sh
index 6abe4e46..bb9d9e66 100644
--- a/tests/tests/basic-posix-consistency.sh
+++ b/tests/tests/basic-posix-consistency.sh
@@ -138,7 +138,9 @@ echo "--- can't overwrite non-empty dir"
 mkdir "$T_D0/dir/a/dir"
 touch "$T_D0/dir/a/dir/nope"
 mkdir "$T_D1/dir/c/clobber"
-mv -T "$T_D1/dir/c/clobber" "$T_D1/dir/a/dir" 2>&1 | t_filter_fs
+mv -T "$T_D1/dir/c/clobber" "$T_D1/dir/a/dir" 2>&1 | \
+		sed "s@mv: cannot move '.*' to '\(.*\)': Directory not empty@mv: cannot overwrite '\1': Directory not empty@g" | \
+		t_filter_fs
 find "$T_D0/dir" -ls 2>&1 | t_filter_fs > "$T_TMP.0"
 find "$T_D1/dir" -ls 2>&1 | t_filter_fs > "$T_TMP.1"
 diff -u "$T_TMP.0" "$T_TMP.1"
diff --git a/tests/tests/format-version-forward-back.sh b/tests/tests/format-version-forward-back.sh
index d907ef49..ed5543c1 100644
--- a/tests/tests/format-version-forward-back.sh
+++ b/tests/tests/format-version-forward-back.sh
@@ -11,8 +11,8 @@
 # format version.
 #
 
-# not supported on el8 or higher
-if [ $(source /etc/os-release ; echo ${VERSION_ID:0:1}) -gt 7 ]; then
+# not supported on el8, or higher versions.
+if [ $(source /etc/os-release ; echo ${VERSION_ID} | cut -d. -f1) -gt 7 ]; then
 	t_skip_permitted "Unsupported OS version"
 fi
 
diff --git a/utils/sparse.sh b/utils/sparse.sh
index adef573b..a31b3630 100755
--- a/utils/sparse.sh
+++ b/utils/sparse.sh
@@ -71,7 +71,7 @@ else
 	m64=""
 fi
 
-sparse $m64 $include $search/include "$@" 2>&1 | egrep -v "($RE)" | tee .sparse.output
+sparse $m64 $include $search/include "$@" 2>&1 | grep -v -E "($RE)" | tee .sparse.output
 
 rm -f $defines