bcachefs: refactor bch_fs_usage

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/alloc_foreground.c

@@ -721,7 +721,7 @@ static struct write_point *__writepoint_find(struct hlist_head *head,
 static inline bool too_many_writepoints(struct bch_fs *c, unsigned factor)
 {
 	u64 stranded	= c->write_points_nr * c->bucket_size_max;
-	u64 free	= bch2_fs_sectors_free(c, bch2_fs_usage_read(c));
+	u64 free	= bch2_fs_sectors_free(c);
 
 	return stranded * factor > free;
 }

fs/bcachefs/bcachefs.h

@@ -503,6 +503,10 @@ enum bch_fs_state {
 	BCH_FS_RW,
 };
 
+struct bch_fs_pcpu {
+	u64			sectors_available;
+};
+
 struct bch_fs {
 	struct closure		cl;
 
@@ -615,6 +619,8 @@ struct bch_fs {
 
 	atomic64_t		sectors_available;
 
+	struct bch_fs_pcpu __percpu	*pcpu;
+
 	struct bch_fs_usage __percpu	*usage[2];
 
 	struct percpu_rw_semaphore	mark_lock;

fs/bcachefs/buckets.h

@@ -164,6 +164,20 @@ static inline bool bucket_unused(struct bucket_mark mark)
 		!bucket_sectors_used(mark);
 }
 
+static inline bool is_available_bucket(struct bucket_mark mark)
+{
+	return (!mark.owned_by_allocator &&
+		!mark.dirty_sectors &&
+		!mark.stripe);
+}
+
+static inline bool bucket_needs_journal_commit(struct bucket_mark m,
+					       u16 last_seq_ondisk)
+{
+	return m.journal_seq_valid &&
+		((s16) m.journal_seq - (s16) last_seq_ondisk > 0);
+}
+
 /* Device usage: */
 
 struct bch_dev_usage __bch2_dev_usage_read(struct bch_dev *, bool);
@@ -207,31 +221,21 @@ static inline u64 dev_buckets_free(struct bch_fs *c, struct bch_dev *ca)
 
 struct bch_fs_usage __bch2_fs_usage_read(struct bch_fs *, bool);
 struct bch_fs_usage bch2_fs_usage_read(struct bch_fs *);
-void bch2_fs_usage_apply(struct bch_fs *, struct bch_fs_usage *,
-			 struct disk_reservation *, struct gc_pos);
 
 u64 bch2_fs_sectors_used(struct bch_fs *, struct bch_fs_usage);
 
-static inline u64 bch2_fs_sectors_free(struct bch_fs *c,
-				       struct bch_fs_usage stats)
-{
-	return c->capacity - bch2_fs_sectors_used(c, stats);
-}
+struct bch_fs_usage_short
+bch2_fs_usage_read_short(struct bch_fs *);
 
-static inline bool is_available_bucket(struct bucket_mark mark)
+static inline u64 bch2_fs_sectors_free(struct bch_fs *c)
 {
-	return (!mark.owned_by_allocator &&
-		!mark.dirty_sectors &&
-		!mark.stripe);
-}
+	struct bch_fs_usage_short usage = bch2_fs_usage_read_short(c);
 
-static inline bool bucket_needs_journal_commit(struct bucket_mark m,
-					       u16 last_seq_ondisk)
-{
-	return m.journal_seq_valid &&
-		((s16) m.journal_seq - (s16) last_seq_ondisk > 0);
+	return usage.capacity - usage.used;
 }
 
+/* key/bucket marking: */
+
 void bch2_bucket_seq_cleanup(struct bch_fs *);
 
 void bch2_invalidate_bucket(struct bch_fs *, struct bch_dev *,
@@ -252,6 +256,10 @@ int bch2_mark_key(struct bch_fs *, struct bkey_s_c,
 		  bool, s64, struct gc_pos,
 		  struct bch_fs_usage *, u64, unsigned);
 void bch2_mark_update(struct btree_insert *, struct btree_insert_entry *);
+void bch2_fs_usage_apply(struct bch_fs *, struct bch_fs_usage *,
+			 struct disk_reservation *, struct gc_pos);
+
+/* disk reservations: */
 
 void __bch2_disk_reservation_put(struct bch_fs *, struct disk_reservation *);
 

fs/bcachefs/buckets_types.h

@@ -73,9 +73,13 @@ struct bch_fs_usage {
 
 	u64			nr_inodes;
 
-	/* fields starting here aren't touched by gc: */
 	u64			online_reserved;
-	u64			available_cache;
+};
+
+struct bch_fs_usage_short {
+	u64			capacity;
+	u64			used;
+	u64			nr_inodes;
 };
 
 /*

fs/bcachefs/chardev.c

@@ -306,7 +306,7 @@ static ssize_t bch2_data_job_read(struct file *file, char __user *buf,
 		.p.btree_id		= ctx->stats.iter.btree_id,
 		.p.pos			= ctx->stats.iter.pos,
 		.p.sectors_done		= atomic64_read(&ctx->stats.sectors_seen),
-		.p.sectors_total	= bch2_fs_sectors_used(c, bch2_fs_usage_read(c)),
+		.p.sectors_total	= bch2_fs_usage_read_short(c).used,
 	};
 
 	if (len < sizeof(e))

fs/bcachefs/fs.c

@@ -1423,16 +1423,14 @@ static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct super_block *sb = dentry->d_sb;
 	struct bch_fs *c = sb->s_fs_info;
-	struct bch_fs_usage usage = bch2_fs_usage_read(c);
-	u64 hidden_metadata = usage.buckets[BCH_DATA_SB] +
-		usage.buckets[BCH_DATA_JOURNAL];
+	struct bch_fs_usage_short usage = bch2_fs_usage_read_short(c);
 	unsigned shift = sb->s_blocksize_bits - 9;
 	u64 fsid;
 
 	buf->f_type	= BCACHEFS_STATFS_MAGIC;
 	buf->f_bsize	= sb->s_blocksize;
-	buf->f_blocks	= (c->capacity - hidden_metadata) >> shift;
-	buf->f_bfree	= (c->capacity - bch2_fs_sectors_used(c, usage)) >> shift;
+	buf->f_blocks	= usage.capacity >> shift;
+	buf->f_bfree	= (usage.capacity - usage.used) >> shift;
 	buf->f_bavail	= buf->f_bfree;
 	buf->f_files	= usage.nr_inodes;
 	buf->f_ffree	= U64_MAX;

fs/bcachefs/super.c

@@ -376,6 +376,7 @@ static void bch2_fs_free(struct bch_fs *c)
 	bch2_fs_compress_exit(c);
 	percpu_free_rwsem(&c->mark_lock);
 	free_percpu(c->usage[0]);
+	free_percpu(c->pcpu);
 	mempool_exit(&c->btree_iters_pool);
 	mempool_exit(&c->btree_bounce_pool);
 	bioset_exit(&c->btree_bio);
@@ -612,6 +613,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 			    offsetof(struct btree_write_bio, wbio.bio)),
 			BIOSET_NEED_BVECS) ||
 	    !(c->usage[0] = alloc_percpu(struct bch_fs_usage)) ||
+	    !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 	    mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 					btree_bytes(c)) ||
 	    mempool_init_kmalloc_pool(&c->btree_iters_pool, 1,