1 files changed, 0 insertions, 353 deletions
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
deleted file mode 100644
index 4bbd3bf34acd..000000000000
--- a/drivers/staging/erofs/utils.c
+++ /dev/null
@@ -1,353 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/drivers/staging/erofs/utils.c
- *
- * Copyright (C) 2018 HUAWEI, Inc.
- *             http://www.huawei.com/
- * Created by Gao Xiang <gaoxiang25@huawei.com>
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file COPYING in the main directory of the Linux
- * distribution for more details.
- */
-
-#include "internal.h"
-#include <linux/pagevec.h>
-
-struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
-{
-	struct page *page;
-
-	if (!list_empty(pool)) {
-		page = lru_to_page(pool);
-		list_del(&page->lru);
-	} else {
-		page = alloc_pages(gfp | __GFP_NOFAIL, 0);
-	}
-	return page;
-}
-
-#if (EROFS_PCPUBUF_NR_PAGES > 0)
-static struct {
-	u8 data[PAGE_SIZE * EROFS_PCPUBUF_NR_PAGES];
-} ____cacheline_aligned_in_smp erofs_pcpubuf[NR_CPUS];
-
-void *erofs_get_pcpubuf(unsigned int pagenr)
-{
-	preempt_disable();
-	return &erofs_pcpubuf[smp_processor_id()].data[pagenr * PAGE_SIZE];
-}
-#endif
-
-/* global shrink count (for all mounted EROFS instances) */
-static atomic_long_t erofs_global_shrink_cnt;
-
-#ifdef CONFIG_EROFS_FS_ZIP
-#define __erofs_workgroup_get(grp)	atomic_inc(&(grp)->refcount)
-#define __erofs_workgroup_put(grp)	atomic_dec(&(grp)->refcount)
-
-static int erofs_workgroup_get(struct erofs_workgroup *grp)
-{
-	int o;
-
-repeat:
-	o = erofs_wait_on_workgroup_freezed(grp);
-	if (unlikely(o <= 0))
-		return -1;
-
-	if (unlikely(atomic_cmpxchg(&grp->refcount, o, o + 1) != o))
-		goto repeat;
-
-	/* decrease refcount paired by erofs_workgroup_put */
-	if (unlikely(o == 1))
-		atomic_long_dec(&erofs_global_shrink_cnt);
-	return 0;
-}
-
-struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
-					     pgoff_t index, bool *tag)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	struct erofs_workgroup *grp;
-
-repeat:
-	rcu_read_lock();
-	grp = radix_tree_lookup(&sbi->workstn_tree, index);
-	if (grp) {
-		*tag = xa_pointer_tag(grp);
-		grp = xa_untag_pointer(grp);
-
-		if (erofs_workgroup_get(grp)) {
-			/* prefer to relax rcu read side */
-			rcu_read_unlock();
-			goto repeat;
-		}
-
-		DBG_BUGON(index != grp->index);
-	}
-	rcu_read_unlock();
-	return grp;
-}
-
-int erofs_register_workgroup(struct super_block *sb,
-			     struct erofs_workgroup *grp,
-			     bool tag)
-{
-	struct erofs_sb_info *sbi;
-	int err;
-
-	/* grp shouldn't be broken or used before */
-	if (unlikely(atomic_read(&grp->refcount) != 1)) {
-		DBG_BUGON(1);
-		return -EINVAL;
-	}
-
-	err = radix_tree_preload(GFP_NOFS);
-	if (err)
-		return err;
-
-	sbi = EROFS_SB(sb);
-	erofs_workstn_lock(sbi);
-
-	grp = xa_tag_pointer(grp, tag);
-
-	/*
-	 * Bump up reference count before making this workgroup
-	 * visible to other users in order to avoid potential UAF
-	 * without serialized by erofs_workstn_lock.
-	 */
-	__erofs_workgroup_get(grp);
-
-	err = radix_tree_insert(&sbi->workstn_tree,
-				grp->index, grp);
-	if (unlikely(err))
-		/*
-		 * it's safe to decrease since the workgroup isn't visible
-		 * and refcount >= 2 (cannot be freezed).
-		 */
-		__erofs_workgroup_put(grp);
-
-	erofs_workstn_unlock(sbi);
-	radix_tree_preload_end();
-	return err;
-}
-
-static void  __erofs_workgroup_free(struct erofs_workgroup *grp)
-{
-	atomic_long_dec(&erofs_global_shrink_cnt);
-	erofs_workgroup_free_rcu(grp);
-}
-
-int erofs_workgroup_put(struct erofs_workgroup *grp)
-{
-	int count = atomic_dec_return(&grp->refcount);
-
-	if (count == 1)
-		atomic_long_inc(&erofs_global_shrink_cnt);
-	else if (!count)
-		__erofs_workgroup_free(grp);
-	return count;
-}
-
-#ifdef EROFS_FS_HAS_MANAGED_CACHE
-/* for cache-managed case, customized reclaim paths exist */
-static void erofs_workgroup_unfreeze_final(struct erofs_workgroup *grp)
-{
-	erofs_workgroup_unfreeze(grp, 0);
-	__erofs_workgroup_free(grp);
-}
-
-static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
-					   struct erofs_workgroup *grp,
-					   bool cleanup)
-{
-	/*
-	 * for managed cache enabled, the refcount of workgroups
-	 * themselves could be < 0 (freezed). So there is no guarantee
-	 * that all refcount > 0 if managed cache is enabled.
-	 */
-	if (!erofs_workgroup_try_to_freeze(grp, 1))
-		return false;
-
-	/*
-	 * note that all cached pages should be unlinked
-	 * before delete it from the radix tree.
-	 * Otherwise some cached pages of an orphan old workgroup
-	 * could be still linked after the new one is available.
-	 */
-	if (erofs_try_to_free_all_cached_pages(sbi, grp)) {
-		erofs_workgroup_unfreeze(grp, 1);
-		return false;
-	}
-
-	/*
-	 * it is impossible to fail after the workgroup is freezed,
-	 * however in order to avoid some race conditions, add a
-	 * DBG_BUGON to observe this in advance.
-	 */
-	DBG_BUGON(xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree,
-						     grp->index)) != grp);
-
-	/*
-	 * if managed cache is enable, the last refcount
-	 * should indicate the related workstation.
-	 */
-	erofs_workgroup_unfreeze_final(grp);
-	return true;
-}
-
-#else
-/* for nocache case, no customized reclaim path at all */
-static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
-					   struct erofs_workgroup *grp,
-					   bool cleanup)
-{
-	int cnt = atomic_read(&grp->refcount);
-
-	DBG_BUGON(cnt <= 0);
-	DBG_BUGON(cleanup && cnt != 1);
-
-	if (cnt > 1)
-		return false;
-
-	DBG_BUGON(xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree,
-						     grp->index)) != grp);
-
-	/* (rarely) could be grabbed again when freeing */
-	erofs_workgroup_put(grp);
-	return true;
-}
-
-#endif
-
-unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
-				       unsigned long nr_shrink,
-				       bool cleanup)
-{
-	pgoff_t first_index = 0;
-	void *batch[PAGEVEC_SIZE];
-	unsigned int freed = 0;
-
-	int i, found;
-repeat:
-	erofs_workstn_lock(sbi);
-
-	found = radix_tree_gang_lookup(&sbi->workstn_tree,
-				       batch, first_index, PAGEVEC_SIZE);
-
-	for (i = 0; i < found; ++i) {
-		struct erofs_workgroup *grp = xa_untag_pointer(batch[i]);
-
-		first_index = grp->index + 1;
-
-		/* try to shrink each valid workgroup */
-		if (!erofs_try_to_release_workgroup(sbi, grp, cleanup))
-			continue;
-
-		++freed;
-		if (unlikely(!--nr_shrink))
-			break;
-	}
-	erofs_workstn_unlock(sbi);
-
-	if (i && nr_shrink)
-		goto repeat;
-	return freed;
-}
-
-#endif
-
-/* protected by 'erofs_sb_list_lock' */
-static unsigned int shrinker_run_no;
-
-/* protects the mounted 'erofs_sb_list' */
-static DEFINE_SPINLOCK(erofs_sb_list_lock);
-static LIST_HEAD(erofs_sb_list);
-
-void erofs_register_super(struct super_block *sb)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-
-	mutex_init(&sbi->umount_mutex);
-
-	spin_lock(&erofs_sb_list_lock);
-	list_add(&sbi->list, &erofs_sb_list);
-	spin_unlock(&erofs_sb_list_lock);
-}
-
-void erofs_unregister_super(struct super_block *sb)
-{
-	spin_lock(&erofs_sb_list_lock);
-	list_del(&EROFS_SB(sb)->list);
-	spin_unlock(&erofs_sb_list_lock);
-}
-
-static unsigned long erofs_shrink_count(struct shrinker *shrink,
-					struct shrink_control *sc)
-{
-	return atomic_long_read(&erofs_global_shrink_cnt);
-}
-
-static unsigned long erofs_shrink_scan(struct shrinker *shrink,
-				       struct shrink_control *sc)
-{
-	struct erofs_sb_info *sbi;
-	struct list_head *p;
-
-	unsigned long nr = sc->nr_to_scan;
-	unsigned int run_no;
-	unsigned long freed = 0;
-
-	spin_lock(&erofs_sb_list_lock);
-	do
-		run_no = ++shrinker_run_no;
-	while (run_no == 0);
-
-	/* Iterate over all mounted superblocks and try to shrink them */
-	p = erofs_sb_list.next;
-	while (p != &erofs_sb_list) {
-		sbi = list_entry(p, struct erofs_sb_info, list);
-
-		/*
-		 * We move the ones we do to the end of the list, so we stop
-		 * when we see one we have already done.
-		 */
-		if (sbi->shrinker_run_no == run_no)
-			break;
-
-		if (!mutex_trylock(&sbi->umount_mutex)) {
-			p = p->next;
-			continue;
-		}
-
-		spin_unlock(&erofs_sb_list_lock);
-		sbi->shrinker_run_no = run_no;
-
-#ifdef CONFIG_EROFS_FS_ZIP
-		freed += erofs_shrink_workstation(sbi, nr, false);
-#endif
-
-		spin_lock(&erofs_sb_list_lock);
-		/* Get the next list element before we move this one */
-		p = p->next;
-
-		/*
-		 * Move this one to the end of the list to provide some
-		 * fairness.
-		 */
-		list_move_tail(&sbi->list, &erofs_sb_list);
-		mutex_unlock(&sbi->umount_mutex);
-
-		if (freed >= nr)
-			break;
-	}
-	spin_unlock(&erofs_sb_list_lock);
-	return freed;
-}
-
-struct shrinker erofs_shrinker_info = {
-	.scan_objects = erofs_shrink_scan,
-	.count_objects = erofs_shrink_count,
-	.seeks = DEFAULT_SEEKS,
-};
-