diff options
Diffstat (limited to 'fs/erofs/utils.c')
-rw-r--r-- | fs/erofs/utils.c | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c deleted file mode 100644 index 518bdd69c823..000000000000 --- a/fs/erofs/utils.c +++ /dev/null @@ -1,287 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 2018 HUAWEI, Inc. - * https://www.huawei.com/ - */ -#include "internal.h" - -struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp) -{ - struct page *page = *pagepool; - - if (page) { - DBG_BUGON(page_ref_count(page) != 1); - *pagepool = (struct page *)page_private(page); - } else { - page = alloc_page(gfp); - } - return page; -} - -void erofs_release_pages(struct page **pagepool) -{ - while (*pagepool) { - struct page *page = *pagepool; - - *pagepool = (struct page *)page_private(page); - put_page(page); - } -} - -#ifdef CONFIG_EROFS_FS_ZIP -/* global shrink count (for all mounted EROFS instances) */ -static atomic_long_t erofs_global_shrink_cnt; - -static bool erofs_workgroup_get(struct erofs_workgroup *grp) -{ - if (lockref_get_not_zero(&grp->lockref)) - return true; - - spin_lock(&grp->lockref.lock); - if (__lockref_is_dead(&grp->lockref)) { - spin_unlock(&grp->lockref.lock); - return false; - } - - if (!grp->lockref.count++) - atomic_long_dec(&erofs_global_shrink_cnt); - spin_unlock(&grp->lockref.lock); - return true; -} - -struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb, - pgoff_t index) -{ - struct erofs_sb_info *sbi = EROFS_SB(sb); - struct erofs_workgroup *grp; - -repeat: - rcu_read_lock(); - grp = xa_load(&sbi->managed_pslots, index); - if (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; -} - -struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, - struct erofs_workgroup *grp) -{ - struct erofs_sb_info *const sbi = EROFS_SB(sb); - struct erofs_workgroup *pre; - - DBG_BUGON(grp->lockref.count < 1); -repeat: - xa_lock(&sbi->managed_pslots); - pre = __xa_cmpxchg(&sbi->managed_pslots, grp->index, - NULL, grp, GFP_KERNEL); - if (pre) { - if (xa_is_err(pre)) { - pre = ERR_PTR(xa_err(pre)); - } else if (!erofs_workgroup_get(pre)) { - /* try to legitimize the current in-tree one */ - xa_unlock(&sbi->managed_pslots); - cond_resched(); - goto repeat; - } - grp = pre; - } - xa_unlock(&sbi->managed_pslots); - return grp; -} - -static void __erofs_workgroup_free(struct erofs_workgroup *grp) -{ - atomic_long_dec(&erofs_global_shrink_cnt); - erofs_workgroup_free_rcu(grp); -} - -void erofs_workgroup_put(struct erofs_workgroup *grp) -{ - if (lockref_put_or_lock(&grp->lockref)) - return; - - DBG_BUGON(__lockref_is_dead(&grp->lockref)); - if (grp->lockref.count == 1) - atomic_long_inc(&erofs_global_shrink_cnt); - --grp->lockref.count; - spin_unlock(&grp->lockref.lock); -} - -static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi, - struct erofs_workgroup *grp) -{ - int free = false; - - spin_lock(&grp->lockref.lock); - if (grp->lockref.count) - goto out; - - /* - * Note that all cached pages should be detached before deleted from - * the XArray. Otherwise some cached pages could be still attached to - * the orphan old workgroup when the new one is available in the tree. - */ - if (erofs_try_to_free_all_cached_folios(sbi, grp)) - goto out; - - /* - * It's 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_erase(&sbi->managed_pslots, grp->index) != grp); - - lockref_mark_dead(&grp->lockref); - free = true; -out: - spin_unlock(&grp->lockref.lock); - if (free) - __erofs_workgroup_free(grp); - return free; -} - -static unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi, - unsigned long nr_shrink) -{ - struct erofs_workgroup *grp; - unsigned int freed = 0; - unsigned long index; - - xa_lock(&sbi->managed_pslots); - xa_for_each(&sbi->managed_pslots, index, grp) { - /* try to shrink each valid workgroup */ - if (!erofs_try_to_release_workgroup(sbi, grp)) - continue; - xa_unlock(&sbi->managed_pslots); - - ++freed; - if (!--nr_shrink) - return freed; - xa_lock(&sbi->managed_pslots); - } - xa_unlock(&sbi->managed_pslots); - return freed; -} - -/* 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_shrinker_register(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_shrinker_unregister(struct super_block *sb) -{ - struct erofs_sb_info *const sbi = EROFS_SB(sb); - - mutex_lock(&sbi->umount_mutex); - /* clean up all remaining workgroups in memory */ - erofs_shrink_workstation(sbi, ~0UL); - - spin_lock(&erofs_sb_list_lock); - list_del(&sbi->list); - spin_unlock(&erofs_sb_list_lock); - mutex_unlock(&sbi->umount_mutex); -} - -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; - - freed += erofs_shrink_workstation(sbi, nr - freed); - - 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; -} - -static struct shrinker *erofs_shrinker_info; - -int __init erofs_init_shrinker(void) -{ - erofs_shrinker_info = shrinker_alloc(0, "erofs-shrinker"); - if (!erofs_shrinker_info) - return -ENOMEM; - - erofs_shrinker_info->count_objects = erofs_shrink_count; - erofs_shrinker_info->scan_objects = erofs_shrink_scan; - - shrinker_register(erofs_shrinker_info); - - return 0; -} - -void erofs_exit_shrinker(void) -{ - shrinker_free(erofs_shrinker_info); -} -#endif /* !CONFIG_EROFS_FS_ZIP */ |