bcachefs: Refactor bch2_trans_commit() path

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

fs/bcachefs/bcachefs.h

@@ -301,7 +301,6 @@ do {									\
 	x(btree_node_sort)			\
 	x(btree_node_read)			\
 	x(btree_gc)				\
-	x(btree_update)				\
 	x(btree_lock_contended_read)		\
 	x(btree_lock_contended_intent)		\
 	x(btree_lock_contended_write)		\

fs/bcachefs/btree_io.h

@@ -62,10 +62,10 @@ bool __bch2_compact_whiteouts(struct bch_fs *, struct btree *, enum compact_mode
 
 static inline unsigned should_compact_bset_lazy(struct btree *b, struct bset_tree *t)
 {
-	unsigned bset_u64s = le16_to_cpu(bset(b, t)->u64s);
-	unsigned dead_u64s = bset_u64s - b->nr.bset_u64s[t - b->set];
+	unsigned total_u64s = bset_u64s(t);
+	unsigned dead_u64s = total_u64s - b->nr.bset_u64s[t - b->set];
 
-	return dead_u64s > 128 && dead_u64s * 3 > bset_u64s;
+	return dead_u64s > 64 && dead_u64s * 3 > total_u64s;
 }
 
 static inline bool bch2_maybe_compact_whiteouts(struct bch_fs *c, struct btree *b)

fs/bcachefs/btree_iter.h

@@ -48,6 +48,11 @@ static inline int btree_iter_err(const struct btree_iter *iter)
 
 /* Iterate over iters within a transaction: */
 
+#define trans_for_each_iter_all(_trans, _iter)				\
+	for (_iter = (_trans)->iters;					\
+	     _iter < (_trans)->iters + (_trans)->nr_iters;		\
+	     _iter++)
+
 static inline struct btree_iter *
 __trans_next_iter(struct btree_trans *trans, unsigned idx)
 {

fs/bcachefs/btree_types.h

@@ -255,7 +255,6 @@ struct btree_insert_entry {
 struct btree_trans {
 	struct bch_fs		*c;
 	unsigned long		ip;
-	u64			commit_start;
 
 	u64			iters_linked;
 	u64			iters_live;
@@ -283,12 +282,11 @@ struct btree_trans {
 	struct disk_reservation *disk_res;
 	unsigned		flags;
 	unsigned		journal_u64s;
+	struct replicas_delta_list *fs_usage_deltas;
 
 	struct btree_iter	iters_onstack[2];
 	struct btree_insert_entry updates_onstack[6];
 	u8			updates_sorted_onstack[6];
-
-	struct replicas_delta_list *fs_usage_deltas;
 };
 
 #define BTREE_FLAG(flag)						\
@@ -420,6 +418,12 @@ static inline unsigned btree_bkey_first_offset(const struct bset_tree *t)
 	__btree_node_offset_to_key(_b, (_t)->end_offset);		\
 })
 
+static inline unsigned bset_u64s(struct bset_tree *t)
+{
+	return t->end_offset - t->data_offset -
+		sizeof(struct bset) / sizeof(u64);
+}
+
 static inline unsigned bset_byte_offset(struct btree *b, void *i)
 {
 	return i - (void *) b->data;

fs/bcachefs/btree_update.h

@@ -93,9 +93,30 @@ int bch2_btree_node_rewrite(struct bch_fs *c, struct btree_iter *,
 int bch2_btree_node_update_key(struct bch_fs *, struct btree_iter *,
 			       struct btree *, struct bkey_i_btree_ptr *);
 
-int bch2_trans_commit(struct btree_trans *,
-		      struct disk_reservation *,
-		      u64 *, unsigned);
+int __bch2_trans_commit(struct btree_trans *);
+
+/**
+ * bch2_trans_commit - insert keys at given iterator positions
+ *
+ * This is main entry point for btree updates.
+ *
+ * Return values:
+ * -EINTR: locking changed, this function should be called again. Only returned
+ *  if passed BTREE_INSERT_ATOMIC.
+ * -EROFS: filesystem read only
+ * -EIO: journal or btree node IO error
+ */
+static inline int bch2_trans_commit(struct btree_trans *trans,
+				    struct disk_reservation *disk_res,
+				    u64 *journal_seq,
+				    unsigned flags)
+{
+	trans->disk_res		= disk_res;
+	trans->journal_seq	= journal_seq;
+	trans->flags		= flags;
+
+	return __bch2_trans_commit(trans);
+}
 
 static inline void bch2_trans_update(struct btree_trans *trans,
 				     struct btree_iter *iter,

fs/bcachefs/fs-io.c

@@ -2720,20 +2720,26 @@ long bch2_fallocate_dispatch(struct file *file, int mode,
 			     loff_t offset, loff_t len)
 {
 	struct bch_inode_info *inode = file_bch_inode(file);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	long ret;
 
-	if (!(mode & ~(FALLOC_FL_KEEP_SIZE|FALLOC_FL_ZERO_RANGE)))
-		return bchfs_fallocate(inode, mode, offset, len);
-
-	if (mode == (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE))
-		return bchfs_fpunch(inode, offset, len);
+	if (!percpu_ref_tryget(&c->writes))
+		return -EROFS;
 
-	if (mode == FALLOC_FL_INSERT_RANGE)
-		return bchfs_fcollapse_finsert(inode, offset, len, true);
+	if (!(mode & ~(FALLOC_FL_KEEP_SIZE|FALLOC_FL_ZERO_RANGE)))
+		ret = bchfs_fallocate(inode, mode, offset, len);
+	else if (mode == (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE))
+		ret = bchfs_fpunch(inode, offset, len);
+	else if (mode == FALLOC_FL_INSERT_RANGE)
+		ret = bchfs_fcollapse_finsert(inode, offset, len, true);
+	else if (mode == FALLOC_FL_COLLAPSE_RANGE)
+		ret = bchfs_fcollapse_finsert(inode, offset, len, false);
+	else
+		ret = -EOPNOTSUPP;
 
-	if (mode == FALLOC_FL_COLLAPSE_RANGE)
-		return bchfs_fcollapse_finsert(inode, offset, len, false);
+	percpu_ref_put(&c->writes);
 
-	return -EOPNOTSUPP;
+	return ret;
 }
 
 static void mark_range_unallocated(struct bch_inode_info *inode,

fs/bcachefs/io.c

@@ -310,6 +310,7 @@ int bch2_extent_update(struct btree_trans *trans,
 	bch2_trans_update(trans, iter, k);
 
 	ret = bch2_trans_commit(trans, disk_res, journal_seq,
+				BTREE_INSERT_NOCHECK_RW|
 				BTREE_INSERT_NOFAIL|
 				BTREE_INSERT_ATOMIC|
 				BTREE_INSERT_USE_RESERVE);

fs/bcachefs/journal.h

@@ -271,7 +271,7 @@ static inline void bch2_journal_res_put(struct journal *j,
 	if (!res->ref)
 		return;
 
-	lock_release(&j->res_map, _RET_IP_);
+	lock_release(&j->res_map, _THIS_IP_);
 
 	while (res->u64s)
 		bch2_journal_add_entry(j, res,

fs/bcachefs/reflink.c

@@ -166,6 +166,9 @@ s64 bch2_remap_range(struct bch_fs *c,
 	u64 src_done, dst_done;
 	int ret = 0, ret2 = 0;
 
+	if (!percpu_ref_tryget(&c->writes))
+		return -EROFS;
+
 	if (!(c->sb.features & (1ULL << BCH_FEATURE_REFLINK))) {
 		mutex_lock(&c->sb_lock);
 		if (!(c->sb.features & (1ULL << BCH_FEATURE_REFLINK))) {
@@ -295,5 +298,7 @@ s64 bch2_remap_range(struct bch_fs *c,
 
 	ret = bch2_trans_exit(&trans) ?: ret;
 
+	percpu_ref_put(&c->writes);
+
 	return dst_done ?: ret ?: ret2;
 }