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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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static void f2fs_free_cache(struct f2fs_cached_block *entry);
void f2fs_cache_wait_writeback_cond(struct f2fs_cached_block *entry, enum page_type type){ /* in case the entry was truncated or on-going shrink */ if (!entry->cache) return;
if (!f2fs_cache_test_writeback(entry)) return;
/* submit cached bio */ f2fs_submit_merged_write_cache(entry->cache->sbi, entry, 0, type);
wait_on_bit_io(&entry->state, F2FS_BLOCK_WRITEBACK, TASK_UNINTERRUPTIBLE);}
void f2fs_cache_wait_writeback(struct f2fs_cached_block *entry){ /* in case the entry was truncated or on-going shrink */ if (!entry->cache) return;
f2fs_cache_wait_writeback_cond(entry, IS_META_CACHE(entry->cache) ? META : NODE);}
void f2fs_cache_update_tag(struct f2fs_cached_block *entry, unsigned int clear_from, unsigned int set_to){ struct f2fs_cached_block_list *cache = entry->cache; unsigned long flags;
spin_lock_irqsave(&cache->tree_lock, flags); if (clear_from != F2FS_CACHE_TAG_NONE) radix_tree_tag_clear(&cache->root, entry->index, clear_from); if (set_to != F2FS_CACHE_TAG_NONE) radix_tree_tag_set(&cache->root, entry->index, set_to); spin_unlock_irqrestore(&cache->tree_lock, flags);}
bool f2fs_mark_cache_dirty(struct f2fs_cached_block *entry){ struct f2fs_cached_block_list *cache = entry->cache;
f2fs_cache_set_uptodate(entry);
#ifdef CONFIG_F2FS_CHECK_FS if (f2fs_is_node_cache(entry) && IS_INODE(cache->sbi, entry)) f2fs_inode_chksum_set(cache->sbi, entry);#endif
if (!f2fs_cache_test_and_set_dirty(entry)) { enum count_type type = IS_META_CACHE(cache) ? F2FS_DIRTY_META : F2FS_DIRTY_NODES;
trace_f2fs_cache_set_dirty(entry, IS_META_CACHE(cache) ? META : NODE); f2fs_cache_update_tag(entry, F2FS_CACHE_TAG_NONE, F2FS_CACHE_TAG_DIRTY); inc_cache_count(cache->sbi, type); f2fs_wake_up_cache_wb(cache->sbi); return true; }
return false;}
void f2fs_drop_cache_dirty(struct f2fs_cached_block *entry){
struct f2fs_cached_block_list *cache = entry->cache; enum count_type type = IS_META_CACHE(cache) ? F2FS_DIRTY_META : F2FS_DIRTY_NODES;
f2fs_cache_clear_uptodate(entry);
if (!f2fs_cache_test_and_clear_dirty(entry)) return;
f2fs_cache_update_tag(entry, F2FS_CACHE_TAG_DIRTY, F2FS_CACHE_TAG_NONE); dec_cache_count(cache->sbi, type);}
void f2fs_start_cache_writeback(struct f2fs_cached_block *entry){ f2fs_cache_set_writeback(entry); f2fs_cache_update_tag(entry, F2FS_CACHE_TAG_DIRTY, F2FS_CACHE_TAG_WRITEBACK);}
/* * The temporary references taken around clear_and_wake_up_bit() are counted * in units of F2FS_CACHE_PIN_BIAS, like GUP_PIN_COUNTING_BIAS for folios, so * that they can be told apart from the regular references. */#define F2FS_CACHE_PIN_BIAS (1 << 16)
static void f2fs_cache_pin(struct f2fs_cached_block *entry){ atomic_add(F2FS_CACHE_PIN_BIAS, &entry->refcount);}
static void f2fs_cache_unpin(struct f2fs_cached_block *entry){ int ref = atomic_sub_return(F2FS_CACHE_PIN_BIAS, &entry->refcount);
WARN_ON_ONCE(ref < 0); if (!ref) f2fs_free_cache(entry);}
void f2fs_end_cache_writeback(struct f2fs_cached_block *entry){ /* * should call f2fs_cache_update_tag() before clearing writeback bit, * in case f2fs_truncate_cache() set entry->cache to NULL. */ f2fs_cache_update_tag(entry, F2FS_CACHE_TAG_WRITEBACK, F2FS_CACHE_TAG_NONE); /* * Writeback does not hold an entry reference of its own, relying * on truncation to wait for the clearing of F2FS_BLOCK_WRITEBACK. * But here we must make sure that the entry is not freed and * reused before clear_and_wake_up_bit(). */ f2fs_cache_pin(entry); clear_and_wake_up_bit(F2FS_BLOCK_WRITEBACK, &entry->state); f2fs_cache_unpin(entry);}
static int f2fs_cache_refcount(struct f2fs_cached_block *entry){ return atomic_read(&entry->refcount);}
/* the number of regular references, excluding the temporary ones */static int f2fs_cache_users(struct f2fs_cached_block *entry){ return f2fs_cache_refcount(entry) & (F2FS_CACHE_PIN_BIAS - 1);}
static void f2fs_do_free_cache(struct f2fs_cached_block *entry){ kfree(entry->data); kfree(entry);}
static void f2fs_free_cache(struct f2fs_cached_block *entry){ WARN_ON_ONCE(!list_empty(&entry->list)); WARN_ON_ONCE(f2fs_cache_refcount(entry)); f2fs_do_free_cache(entry);}
void f2fs_cache_get(struct f2fs_cached_block *entry){ atomic_inc(&entry->refcount);}
static bool f2fs_cache_put(struct f2fs_cached_block *entry){ WARN_ON_ONCE(!f2fs_cache_refcount(entry)); if (atomic_dec_and_test(&entry->refcount)) { f2fs_free_cache(entry); return true; } return false;}
static struct f2fs_cached_block *f2fs_create_cache( struct f2fs_cached_block_list *cache, unsigned long index, bool nofail){ struct f2fs_sb_info *sbi = cache->sbi; struct f2fs_cached_block *entry; unsigned int flags = GFP_NOFS;
if (index == ULONG_MAX) return ERR_PTR(-ERANGE);
if (nofail) { flags |= __GFP_NOFAIL; entry = kzalloc_obj(*entry, flags); entry->data = kmalloc(sbi->blocksize, flags); } else { entry = f2fs_kzalloc(sbi, sizeof(*entry), flags); if (!entry) return ERR_PTR(-ENOMEM);
entry->data = f2fs_kmalloc(sbi, sbi->blocksize, flags); if (!entry->data) { kfree(entry); return ERR_PTR(-ENOMEM); } } entry->index = index;
atomic_set(&entry->refcount, 0); if (!IS_COMPRESS_CACHE(cache)) entry->next_entry = NULL; else entry->ino = 0; INIT_LIST_HEAD(&entry->list);
entry->cache = cache;
return entry;}
static struct f2fs_cached_block *f2fs_insert_cache( struct f2fs_cached_block_list *cache, unsigned long index, struct f2fs_cached_block *new){ struct f2fs_cached_block *e; int ret; unsigned long flags;
ret = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); f2fs_bug_on(cache->sbi, ret);
spin_lock(&cache->list_lock); spin_lock_irqsave(&cache->tree_lock, flags); e = radix_tree_lookup(&cache->root, index); if (!e) { e = new; f2fs_bug_on(cache->sbi, f2fs_cache_refcount(e));
ret = radix_tree_insert(&cache->root, index, e); f2fs_bug_on(cache->sbi, ret);
/* radix tree referenced cache entry */ f2fs_cache_get(e); f2fs_bug_on(cache->sbi, !list_empty(&e->list)); list_add_tail(&e->list, &cache->lru_list); cache->num_entries++; } f2fs_cache_get(e); spin_unlock_irqrestore(&cache->tree_lock, flags); spin_unlock(&cache->list_lock); radix_tree_preload_end();
if (new != e) { f2fs_bug_on(cache->sbi, f2fs_cache_refcount(new)); f2fs_do_free_cache(new); }
return e;}
struct f2fs_cached_block *f2fs_find_cache( struct f2fs_cached_block_list *cache, unsigned long index, enum f2fs_cache_request_flag rflag){ struct f2fs_cached_block *entry; unsigned long flags; bool access = rflag & F2FS_CACHE_ACCESS;
spin_lock_irqsave(&cache->tree_lock, flags); entry = radix_tree_lookup(&cache->root, index); if (entry) { f2fs_bug_on(cache->sbi, !f2fs_cache_refcount(entry)); f2fs_cache_get(entry); if (access && !f2fs_cache_test_referenced(entry)) f2fs_cache_set_referenced(entry); } else { entry = ERR_PTR(-ENOENT); } spin_unlock_irqrestore(&cache->tree_lock, flags);
return entry;}
struct f2fs_cached_block *f2fs_grab_cache( struct f2fs_cached_block_list *cache, unsigned long index, int flags)
{ struct f2fs_cached_block *entry, *new; bool create = flags & F2FS_CACHE_CREATE; bool nofail = flags & F2FS_CACHE_NOFAIL; bool lock = flags & F2FS_CACHE_LOCK;
repeat: entry = f2fs_find_cache(cache, index, F2FS_CACHE_ACCESS); if (!IS_ERR(entry)) goto found;
if (!create) return ERR_PTR(-ENOENT);
new = f2fs_create_cache(cache, index, nofail); if (IS_ERR(new)) return new;
entry = f2fs_insert_cache(cache, index, new);found: if (lock) { f2fs_lock_cache(entry); /* has been truncated */ if (entry->cache != cache) { f2fs_put_cache(entry, true); goto repeat; } } return entry;}
bool f2fs_trylock_cache(struct f2fs_cached_block *entry){ return !test_and_set_bit(F2FS_BLOCK_LOCKED, &entry->state);}
void f2fs_lock_cache(struct f2fs_cached_block *entry){ wait_on_bit_lock(&entry->state, F2FS_BLOCK_LOCKED, TASK_UNINTERRUPTIBLE);}
void f2fs_unlock_cache(struct f2fs_cached_block *entry){ /* * In asynchronous read I/O completion (e.g. from f2fs_ra_node_cache()), * the I/O completion does not hold a reference of its own. Once * clear_and_wake_up_bit() clears F2FS_BLOCK_LOCKED, a concurrent waiter * in f2fs_lock_cache() (e.g. from f2fs_truncate_cache()) can wake up, * truncate the entry, and drop the final reference before wake_up_bit() * finishes. * Pin the entry here to make sure it is not freed before wake_up_bit() * completes. */ f2fs_cache_pin(entry); clear_and_wake_up_bit(F2FS_BLOCK_LOCKED, &entry->state); f2fs_cache_unpin(entry);}
bool f2fs_put_cache(struct f2fs_cached_block *entry, bool unlock){ if (IS_ERR_OR_NULL(entry)) return false; if (unlock) f2fs_unlock_cache(entry); return f2fs_cache_put(entry);}
unsigned int f2fs_cache_gang_lookup(struct f2fs_cached_block_list *cache, struct f2fs_cached_block **entries, pgoff_t *index, unsigned long end){ unsigned long flags; unsigned int max_nr = min((unsigned long)F2FS_ONSTACK_CACHES, end - *index); int nr, i;
if (*index >= end || *index == ULONG_MAX) return 0;
spin_lock_irqsave(&cache->tree_lock, flags); nr = radix_tree_gang_lookup(&cache->root, (void **)entries, *index, max_nr); if (!nr) goto out_unlock;
for (i = 0; i < nr; i++) { struct f2fs_cached_block *entry = entries[i];
if (entry->index >= end) { nr = i; break; } f2fs_cache_get(entry); } if (nr) *index = entries[nr - 1]->index + 1;out_unlock: spin_unlock_irqrestore(&cache->tree_lock, flags); return nr;}
unsigned int f2fs_cache_gang_lookup_tag(struct f2fs_cached_block_list *cache, struct f2fs_cached_block **entries, pgoff_t *index, unsigned int max_nr, int tag){ unsigned long flags; int nr, i;
if (*index == ULONG_MAX) return 0;
spin_lock_irqsave(&cache->tree_lock, flags); nr = radix_tree_gang_lookup_tag(&cache->root, (void **)entries, *index, max_nr, tag); if (!nr) goto out;
for (i = 0; i < nr; i++) f2fs_cache_get(entries[i]); *index = entries[nr - 1]->index + 1;out: spin_unlock_irqrestore(&cache->tree_lock, flags); return nr;}
void f2fs_cache_gang_release(struct f2fs_cached_block **entries, unsigned int nr_entries){ int i;
for (i = 0; i < nr_entries; i++) f2fs_put_cache(entries[i], false);}
void f2fs_cache_wait_on_all_writeback(struct f2fs_cached_block_list *cache){ unsigned long index = 0; struct f2fs_cached_block *entries[F2FS_ONSTACK_CACHES]; int nr, i;
next: nr = f2fs_cache_gang_lookup_tag(cache, entries, &index, F2FS_ONSTACK_CACHES, F2FS_CACHE_TAG_WRITEBACK); if (!nr) return;
for (i = 0; i < nr; i++) f2fs_cache_wait_writeback(entries[i]); f2fs_cache_gang_release(entries, nr);
cond_resched(); goto next;}
static void f2fs_do_truncate_cache(struct f2fs_cached_block *entry, bool drop_dirty){ struct f2fs_cached_block_list *cache = entry->cache; unsigned long flags;
if (drop_dirty) goto drop_it;
if (f2fs_cache_test_dirty(entry) || f2fs_cache_test_writeback(entry)) return;
drop_it: f2fs_cache_wait_writeback(entry); f2fs_drop_cache_dirty(entry);
spin_lock(&cache->list_lock); spin_lock_irqsave(&cache->tree_lock, flags);
f2fs_bug_on(cache->sbi, !entry->cache); if (!radix_tree_delete(&cache->root, entry->index)) f2fs_bug_on(cache->sbi, !entry->cache);
entry->cache = NULL; cache->num_entries--;
atomic_dec(&entry->refcount); f2fs_bug_on(cache->sbi, !f2fs_cache_refcount(entry));
f2fs_bug_on(cache->sbi, list_empty(&entry->list)); list_del_init(&entry->list);
spin_unlock_irqrestore(&cache->tree_lock, flags); spin_unlock(&cache->list_lock);}
void f2fs_truncate_locked_cache(struct f2fs_cached_block *entry, bool drop_dirty){ if (!entry->cache) return; f2fs_do_truncate_cache(entry, drop_dirty);}
void f2fs_truncate_cache(struct f2fs_cached_block *entry, bool drop_dirty){ f2fs_lock_cache(entry); f2fs_truncate_locked_cache(entry, drop_dirty); f2fs_unlock_cache(entry);}
static void f2fs_drop_cache(struct f2fs_cached_block_list *cache, block_t blkaddr, bool drop_dirty){ struct f2fs_cached_block *entry;
entry = f2fs_find_cache(cache, blkaddr, 0); if (IS_ERR(entry)) return;
f2fs_truncate_cache(entry, drop_dirty); f2fs_put_cache(entry, false);}
void f2fs_drop_cache_range(struct f2fs_cached_block_list *cache, unsigned long start, unsigned long len, bool drop_dirty){ unsigned long index = start; unsigned long end = (ULONG_MAX - start < len) ? ULONG_MAX : (start + len); struct f2fs_cached_block *entries[F2FS_ONSTACK_CACHES]; int nr, i;
if (len == 1) return f2fs_drop_cache(cache, index, drop_dirty);
next: nr = f2fs_cache_gang_lookup(cache, entries, &index, end); if (!nr) return;
for (i = 0; i < nr; i++) f2fs_truncate_cache(entries[i], drop_dirty); f2fs_cache_gang_release(entries, nr);
if (index < end) { cond_resched(); goto next; }}
int f2fs_init_cache(struct f2fs_sb_info *sbi, struct f2fs_cached_block_list *cache, enum f2fs_cache_type type){ cache->sbi = sbi; cache->type = type; INIT_RADIX_TREE(&cache->root, GFP_ATOMIC); spin_lock_init(&cache->tree_lock); spin_lock_init(&cache->list_lock); INIT_LIST_HEAD(&cache->lru_list); cache->num_entries = 0;
return 0;}
void f2fs_destroy_cache(struct f2fs_cached_block_list *cache){ struct list_head *head = &cache->lru_list; struct f2fs_cached_block *entry; unsigned long flags;
f2fs_cache_wait_on_all_writeback(cache);next: spin_lock(&cache->list_lock); if (list_empty(head)) { spin_unlock(&cache->list_lock); return; } entry = list_first_entry(head, struct f2fs_cached_block, list);
spin_lock_irqsave(&cache->tree_lock, flags); radix_tree_delete(&cache->root, entry->index); cache->num_entries--; list_del_init(&entry->list); spin_unlock_irqrestore(&cache->tree_lock, flags);
spin_unlock(&cache->list_lock);
/* wait on read cache IO */ f2fs_lock_cache(entry); /* wait on write cache IO */ f2fs_cache_wait_writeback(entry); f2fs_bug_on(cache->sbi, f2fs_cache_test_dirty(entry)); f2fs_bug_on(cache->sbi, f2fs_cache_test_writeback(entry)); f2fs_bug_on(cache->sbi, !list_empty(&entry->list)); /* the I/O completion may not have unpinned the entry yet */ f2fs_bug_on(cache->sbi, f2fs_cache_users(entry) != 1); f2fs_put_cache(entry, true); goto next;}
static unsigned long f2fs_do_shrink_cache(struct f2fs_cached_block_list *cache, unsigned long nr_to_scan){ struct f2fs_cached_block *entry, *next; LIST_HEAD(dispose_list); LIST_HEAD(keep_list); unsigned long freed = 0; unsigned long scanned = 0;
/* Phase 1: Isolate candidate entries from LRU list into dispose_list */ spin_lock(&cache->list_lock); list_for_each_entry_safe(entry, next, &cache->lru_list, list) { if (scanned >= cache->num_entries) break; if (scanned++ >= nr_to_scan) break;
/* If accessed, give it a second chance to rotate to tail */ if (f2fs_cache_test_and_clear_referenced(entry)) { list_move_tail(&entry->list, &cache->lru_list); continue; }
if (f2fs_cache_test_dirty(entry) || f2fs_cache_test_writeback(entry) || f2fs_cache_test_locked(entry)) continue;
if (f2fs_cache_refcount(entry) != 1) continue;
list_move_tail(&entry->list, &dispose_list); } spin_unlock(&cache->list_lock);
/* Phase 2: Process isolated candidates one by one */ while (1) { spin_lock(&cache->list_lock); entry = list_first_entry_or_null(&dispose_list, struct f2fs_cached_block, list); if (!entry) { spin_unlock(&cache->list_lock); break; } f2fs_cache_get(entry); list_move_tail(&entry->list, &keep_list); spin_unlock(&cache->list_lock);
if (!f2fs_trylock_cache(entry)) { f2fs_put_cache(entry, false); continue; }
/* the entry has been truncated */ if (!entry->cache) { f2fs_put_cache(entry, true); continue; } /* * at least there are shrinker, radix tree and another user * has referenced the entry. */ if (f2fs_cache_refcount(entry) >= 3) { f2fs_put_cache(entry, true); continue; }
f2fs_do_truncate_cache(entry, false);
if (f2fs_put_cache(entry, true)) freed++; }
/* Phase 3: Splice un-reclaimed entries back onto cache->lru_list */ if (!list_empty(&keep_list)) { spin_lock(&cache->list_lock); list_splice_tail(&keep_list, &cache->lru_list); spin_unlock(&cache->list_lock); }
return freed;}
unsigned long f2fs_shrink_cache(struct f2fs_sb_info *sbi, unsigned long nr_to_scan){ unsigned long freed;
freed = f2fs_do_shrink_cache(META_CACHE(sbi), nr_to_scan); if (freed >= nr_to_scan) return freed;
freed += f2fs_do_shrink_cache(NODE_CACHE(sbi), nr_to_scan - freed); if (freed >= nr_to_scan) return freed;
freed += f2fs_do_shrink_cache(COMPRESS_CACHE(sbi), nr_to_scan - freed); return freed;}
unsigned long f2fs_shrink_meta_cache(struct f2fs_sb_info *sbi, unsigned long nr_to_scan){ return f2fs_do_shrink_cache(META_CACHE(sbi), nr_to_scan);}
unsigned long f2fs_shrink_node_cache(struct f2fs_sb_info *sbi, unsigned long nr_to_scan){ return f2fs_do_shrink_cache(NODE_CACHE(sbi), nr_to_scan);}
static inline unsigned long f2fs_total_cached_entries(struct f2fs_sb_info *sbi){ unsigned long total = READ_ONCE(META_CACHE(sbi)->num_entries) + READ_ONCE(NODE_CACHE(sbi)->num_entries);#ifdef CONFIG_F2FS_FS_COMPRESSION if (test_opt(sbi, COMPRESS_CACHE)) total += READ_ONCE(COMPRESS_CACHE(sbi)->num_entries);#endif return total;}
static inline s64 f2fs_nr_dirty_caches(struct f2fs_sb_info *sbi){ return get_nr_caches(sbi, F2FS_DIRTY_META) + get_nr_caches(sbi, F2FS_DIRTY_NODES);}
/* * f2fs_write_{meta,node}_caches() skip writeback until there are enough * dirty caches to gather, so don't wake up f2fs_writeback for nothing. */static inline bool f2fs_cache_wb_collectable(struct f2fs_sb_info *sbi, s64 nr_dirty, int type){ return nr_dirty && nr_dirty >= nr_caches_to_skip(sbi, type);}
static bool f2fs_cache_wb_exceeded(struct f2fs_sb_info *sbi){ struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; unsigned int total_threshold, dirty_threshold; s64 nr_meta, nr_node;
total_threshold = READ_ONCE(cache_thread->cache_wb_total_threshold); dirty_threshold = READ_ONCE(cache_thread->cache_wb_dirty_threshold);
/* * Both thresholds are disabled, rely on periodic writeback only, * unless checkpoint is disabled, as nothing else will flush dirty * caches then. */ if (!total_threshold && !dirty_threshold && !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) return false;
if (total_threshold && f2fs_total_cached_entries(sbi) < total_threshold) return false;
nr_meta = get_nr_caches(sbi, F2FS_DIRTY_META); nr_node = get_nr_caches(sbi, F2FS_DIRTY_NODES);
if (dirty_threshold && nr_meta + nr_node < dirty_threshold) return false;
return f2fs_cache_wb_collectable(sbi, nr_meta, META) || f2fs_cache_wb_collectable(sbi, nr_node, NODE);}
static bool f2fs_should_wake_up_cache_wb(struct f2fs_sb_info *sbi){ /* last round made no progress, wait for periodic writeback */ if (READ_ONCE(sbi->cache_thread.cache_wb_throttled)) return false;
return f2fs_cache_wb_exceeded(sbi);}
static int f2fs_cache_writeback_kthread(void *data){ struct f2fs_sb_info *sbi = data; struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; wait_queue_head_t *wq = &cache_thread->cache_wb_wq;
set_freezable();
while (!kthread_should_stop()) { unsigned int interval = READ_ONCE(cache_thread->cache_wb_interval); long nr_meta = 0, nr_node = 0; s64 nr_dirty;
wait_event_freezable_timeout(*wq, kthread_should_stop() || f2fs_should_wake_up_cache_wb(sbi), msecs_to_jiffies(interval));
if (kthread_should_stop()) break;
/* * If thresholds are exceeded, throttle threshold based wakeup * until a round makes progress, otherwise we may busy-loop if * this round can not write anything, e.g. on cp_error, freezing, * frozen fs, or lock contention. */ WRITE_ONCE(cache_thread->cache_wb_throttled, f2fs_cache_wb_exceeded(sbi));
if (f2fs_readonly(sbi->sb)) continue;
if (f2fs_cp_error(sbi)) continue;
if (unlikely(freezing(current))) continue;
if (!sb_start_write_trylock(sbi->sb)) continue;
nr_dirty = f2fs_nr_dirty_caches(sbi);
f2fs_write_meta_caches(sbi, &nr_meta); f2fs_write_node_caches(sbi, &nr_node);
sb_end_write(sbi->sb);
/* * Don't rely on the delta of dirty caches only, as caches may * be dirtied concurrently; also count in caches cleaned by * others, e.g. checkpoint triggered by f2fs_balance_fs_bg(). */ if (nr_meta || nr_node || f2fs_nr_dirty_caches(sbi) < nr_dirty) WRITE_ONCE(cache_thread->cache_wb_throttled, false);
cond_resched(); } return 0;}
void f2fs_wake_up_cache_wb(struct f2fs_sb_info *sbi){ struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread;
/* pairs with smp_store_release() in f2fs_start_cache_wb_thread() */ if (!smp_load_acquire(&cache_thread->cache_wb_task)) return;
if (!f2fs_should_wake_up_cache_wb(sbi)) return;
if (wq_has_sleeper(&cache_thread->cache_wb_wq)) wake_up(&cache_thread->cache_wb_wq);}
int f2fs_start_cache_wb_thread(struct f2fs_sb_info *sbi){ struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; struct task_struct *task; dev_t dev = sbi->sb->s_dev; char name[36];
if (cache_thread->cache_wb_task) return 0;
init_waitqueue_head(&cache_thread->cache_wb_wq); cache_thread->cache_wb_interval = DEF_DIRTY_CACHE_TIMEOUT; cache_thread->cache_wb_dirty_threshold = DEF_CACHE_WB_DIRTY_THRESH; cache_thread->cache_wb_total_threshold = 0; cache_thread->cache_wb_throttled = false; snprintf(name, sizeof(name), "f2fs_writeback-%u:%u", MAJOR(dev), MINOR(dev));
task = kthread_run(f2fs_cache_writeback_kthread, sbi, "%s", name); if (IS_ERR(task)) return PTR_ERR(task);
/* pairs with smp_load_acquire() in f2fs_wake_up_cache_wb() */ smp_store_release(&cache_thread->cache_wb_task, task); return 0;}
void f2fs_stop_cache_wb_thread(struct f2fs_sb_info *sbi){ struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread;
if (!cache_thread->cache_wb_task) return;
kthread_stop(cache_thread->cache_wb_task); WRITE_ONCE(cache_thread->cache_wb_task, NULL);}