Re: [f2fs-dev] [PATCH v8 08/12] f2fs: cache: initialize compress cache

From: Zhiguo Niu

Date: Wed Sep 16 2026 - 05:20:30 EST

Chao Yu via Linux-f2fs-devel <linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx>
于2026年9月16日周三 09:57写道：
>
> From: Chao Yu <chao@xxxxxxxxxx>
>
> This patch introduces compress_blocks in f2fs_sb_info structure, initializes
> and destroys the compress cache during filesystem mount and unmount.
>
> It adds an ino union field in struct f2fs_cached_block (sharing space
> with writeback linkage for zero memory overhead) to track per-inode
> cached blocks, and registers compress cache into the memory shrinker.
>
> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Reviewed-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
thanks!
> ---
> fs/f2fs/cache.c | 9 ++++++++-
> fs/f2fs/cache.h | 14 ++++++++++----
> fs/f2fs/f2fs.h | 6 ++++++
> fs/f2fs/super.c | 7 +++++--
> 4 files changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/cache.c b/fs/f2fs/cache.c
> index 3abd469dc011..3e6a198ef3b3 100644
> --- a/fs/f2fs/cache.c
> +++ b/fs/f2fs/cache.c
> @@ -176,7 +176,10 @@ static struct f2fs_cached_block *f2fs_create_cache(
> entry->index = index;
>
> atomic_set(&entry->refcount, 0);
> - entry->next_entry = NULL;
> + if (!IS_COMPRESS_CACHE(cache))
> + entry->next_entry = NULL;
> + else
> + entry->ino = 0;
> INIT_LIST_HEAD(&entry->list);
>
> entry->cache = cache;
> @@ -631,6 +634,10 @@ unsigned long f2fs_shrink_cache(struct f2fs_sb_info *sbi,
> 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;
> }
>
> diff --git a/fs/f2fs/cache.h b/fs/f2fs/cache.h
> index a36ee57adb1a..a8c24f5282fa 100644
> --- a/fs/f2fs/cache.h
> +++ b/fs/f2fs/cache.h
> @@ -18,12 +18,15 @@ struct f2fs_rwsem;
> struct f2fs_io_info;
> enum page_type;
>
> -/* Represents a single cached block (meta, node) */
> +/* Represents a single cached block (meta, node or compress) */
> struct f2fs_cached_block {
> struct list_head list; /* LRU list head */
> struct f2fs_cached_block_list *cache; /* parent cache list */
> - struct f2fs_cached_block *next_entry; /* chain for merged BIO */
> - unsigned long index; /* key in radix tree, (meta: pba, node: nid) */
> + union {
> + struct f2fs_cached_block *next_entry;/* chain for merged BIO */
> + nid_t ino; /* inode number for compress cache */
> + };
> + unsigned long index; /* key in radix tree, (meta/compress: pba, node: nid) */
> unsigned long state; /* cache entry state (e.g., Dirty, UpToDate) */
> void *data; /* blocksize-aligned memory (4KB or 16KB) */
> atomic_t refcount; /* reference count */
> @@ -34,6 +37,7 @@ struct f2fs_sb_info;
> enum f2fs_cache_type {
> F2FS_META_CACHE,
> F2FS_NODE_CACHE,
> + F2FS_COMPRESS_CACHE,
> };
>
> /* Main cache control structure (per sb_info) */
> @@ -43,12 +47,13 @@ struct f2fs_cached_block_list {
> spinlock_t tree_lock; /* Lock for radix tree */
> struct list_head lru_list; /* Single global LRU list */
> spinlock_t list_lock; /* Lock for LRU list */
> - enum f2fs_cache_type type; /* Cache type (Node or Meta) */
> + enum f2fs_cache_type type; /* Cache type (Node, Meta, Compress) */
> unsigned long num_entries; /* Current number of entries */
> };
>
> #define IS_META_CACHE(cache) ((cache)->type == F2FS_META_CACHE)
> #define IS_NODE_CACHE(cache) ((cache)->type == F2FS_NODE_CACHE)
> +#define IS_COMPRESS_CACHE(cache) ((cache)->type == F2FS_COMPRESS_CACHE)
>
> /* Flags for f2fs_cached_block state */
> enum f2fs_cached_state {
> @@ -196,6 +201,7 @@ void f2fs_drop_cache_range(struct f2fs_cached_block_list *cache,
>
> #define META_CACHE(sbi) (&(sbi)->meta_blocks)
> #define NODE_CACHE(sbi) (&(sbi)->node_blocks)
> +#define COMPRESS_CACHE(sbi) (&(sbi)->compress_blocks)
>
> #define f2fs_find_meta_cache(sbi, blkaddr) \
> f2fs_find_cache(META_CACHE(sbi), blkaddr, 0)
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index d6681276708e..1e23e02cac8b 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2106,6 +2106,7 @@ struct f2fs_sb_info {
> /* f2fs internal cache */
> struct f2fs_cached_block_list meta_blocks;
> struct f2fs_cached_block_list node_blocks;
> + struct f2fs_cached_block_list compress_blocks;
>
> /* internal cache flush thread */
> struct f2fs_cache_kthread cache_thread;
> @@ -2384,6 +2385,11 @@ static inline bool f2fs_is_node_cache(struct f2fs_cached_block *entry)
> return entry->cache && entry->cache == NODE_CACHE(entry->cache->sbi);
> }
>
> +static inline bool f2fs_is_compress_cache(struct f2fs_cached_block *entry)
> +{
> + return entry->cache && entry->cache == COMPRESS_CACHE(entry->cache->sbi);
> +}
> +
> static inline struct f2fs_bio *F2FS_BIO(struct bio *bio)
> {
> return container_of(bio, struct f2fs_bio, bio);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index bf42fbffa348..47259e8172fc 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2071,6 +2071,7 @@ static void f2fs_put_super(struct super_block *sb)
>
> f2fs_destroy_compress_inode(sbi);
>
> + f2fs_destroy_cache(COMPRESS_CACHE(sbi));
> f2fs_destroy_cache(NODE_CACHE(sbi));
> f2fs_destroy_cache(META_CACHE(sbi));
>
> @@ -5263,11 +5264,12 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
>
> f2fs_init_cache(sbi, META_CACHE(sbi), F2FS_META_CACHE);
> f2fs_init_cache(sbi, NODE_CACHE(sbi), F2FS_NODE_CACHE);
> + f2fs_init_cache(sbi, COMPRESS_CACHE(sbi), F2FS_COMPRESS_CACHE);
>
> err = f2fs_get_valid_checkpoint(sbi);
> if (err) {
> f2fs_err(sbi, "Failed to get valid F2FS checkpoint");
> - goto free_node_cache;
> + goto free_compress_cache;
> }
>
> if (__is_set_ckpt_flags(F2FS_CKPT(sbi), CP_QUOTA_NEED_FSCK_FLAG))
> @@ -5582,7 +5584,8 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
> free_devices:
> destroy_device_list(sbi);
> kvfree(sbi->ckpt);
> -free_node_cache:
> +free_compress_cache:
> + f2fs_destroy_cache(COMPRESS_CACHE(sbi));
> f2fs_destroy_cache(NODE_CACHE(sbi));
> f2fs_destroy_cache(META_CACHE(sbi));
> f2fs_destroy_page_array_cache(sbi);
> --
> 2.49.0
>
>
>
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