bcachefs: bch_sb_field_journal_v2

Add a new superblock field which represents journal buckets as ranges:
also move code for the superblock journal fields to journal_sb.c.

This also reworks the code for resizing the journal to write the new
superblock before using the new journal buckets, and thus be a bit
safer.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

7 files changed, 395 insertions, 166 deletions

diff --git a/fs/bcachefs/Makefile b/fs/bcachefs/Makefile
index 65eeab56cb4b..d3808249948c 100644
--- a/fs/bcachefs/Makefile
+++ b/fs/bcachefs/Makefile
@@ -38,6 +38,7 @@ bcachefs-y		:=	\
 	journal.o		\
 	journal_io.o		\
 	journal_reclaim.o	\
+	journal_sb.o		\
 	journal_seq_blacklist.o	\
 	keylist.o		\
 	migrate.o		\
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 2c9243031dab..838754ad60c3 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -1027,16 +1027,17 @@ struct bch_sb_field {
 	__le32			type;
 };
 
-#define BCH_SB_FIELDS()		\
-	x(journal,	0)	\
-	x(members,	1)	\
-	x(crypt,	2)	\
-	x(replicas_v0,	3)	\
-	x(quota,	4)	\
-	x(disk_groups,	5)	\
-	x(clean,	6)	\
-	x(replicas,	7)	\
-	x(journal_seq_blacklist, 8)
+#define BCH_SB_FIELDS()				\
+	x(journal,	0)			\
+	x(members,	1)			\
+	x(crypt,	2)			\
+	x(replicas_v0,	3)			\
+	x(quota,	4)			\
+	x(disk_groups,	5)			\
+	x(clean,	6)			\
+	x(replicas,	7)			\
+	x(journal_seq_blacklist, 8)		\
+	x(journal_v2,	9)
 
 enum bch_sb_field_type {
 #define x(f, nr)	BCH_SB_FIELD_##f = nr,
@@ -1045,6 +1046,14 @@ enum bch_sb_field_type {
 	BCH_SB_FIELD_NR
 };
 
+/*
+ * Most superblock fields are replicated in all device's superblocks - a few are
+ * not:
+ */
+#define BCH_SINGLE_DEVICE_SB_FIELDS		\
+	((1U << BCH_SB_FIELD_journal)|		\
+	 (1U << BCH_SB_FIELD_journal_v2))
+
 /* BCH_SB_FIELD_journal: */
 
 struct bch_sb_field_journal {
@@ -1052,6 +1061,15 @@ struct bch_sb_field_journal {
 	__le64			buckets[0];
 };
 
+struct bch_sb_field_journal_v2 {
+	struct bch_sb_field	field;
+
+	struct bch_sb_field_journal_v2_entry {
+		__le64		start;
+		__le64		nr;
+	}			d[0];
+};
+
 /* BCH_SB_FIELD_members: */
 
 #define BCH_MIN_NR_NBUCKETS	(1 << 6)
diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c
index c7f1674ed596..cb15d1c8a135 100644
--- a/fs/bcachefs/journal.c
+++ b/fs/bcachefs/journal.c
@@ -15,8 +15,8 @@
 #include "journal.h"
 #include "journal_io.h"
 #include "journal_reclaim.h"
+#include "journal_sb.h"
 #include "journal_seq_blacklist.h"
-#include "super-io.h"
 #include "trace.h"
 
 #define x(n)	#n,
@@ -779,28 +779,55 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
 {
 	struct bch_fs *c = ca->fs;
 	struct journal_device *ja = &ca->journal;
-	struct bch_sb_field_journal *journal_buckets;
 	u64 *new_bucket_seq = NULL, *new_buckets = NULL;
+	struct open_bucket **ob = NULL;
+	long *bu = NULL;
+	unsigned i, nr_got = 0, nr_want = nr - ja->nr;
+	unsigned old_nr			= ja->nr;
+	unsigned old_discard_idx	= ja->discard_idx;
+	unsigned old_dirty_idx_ondisk	= ja->dirty_idx_ondisk;
+	unsigned old_dirty_idx		= ja->dirty_idx;
+	unsigned old_cur_idx		= ja->cur_idx;
 	int ret = 0;
 
-	/* don't handle reducing nr of buckets yet: */
-	if (nr <= ja->nr)
-		return 0;
+	if (c) {
+		bch2_journal_flush_all_pins(&c->journal);
+		bch2_journal_block(&c->journal);
+	}
 
+	bu		= kzalloc(nr_want * sizeof(*bu), GFP_KERNEL);
+	ob		= kzalloc(nr_want * sizeof(*ob), GFP_KERNEL);
 	new_buckets	= kzalloc(nr * sizeof(u64), GFP_KERNEL);
 	new_bucket_seq	= kzalloc(nr * sizeof(u64), GFP_KERNEL);
-	if (!new_buckets || !new_bucket_seq) {
+	if (!bu || !ob || !new_buckets || !new_bucket_seq) {
 		ret = -ENOMEM;
-		goto err;
+		goto err_unblock;
 	}
 
-	journal_buckets = bch2_sb_resize_journal(&ca->disk_sb,
-					nr + sizeof(*journal_buckets) / sizeof(u64));
-	if (!journal_buckets) {
-		ret = -ENOSPC;
-		goto err;
+	for (nr_got = 0; nr_got < nr_want; nr_got++) {
+		if (new_fs) {
+			bu[nr_got] = bch2_bucket_alloc_new_fs(ca);
+			if (bu[nr_got] < 0) {
+				ret = -ENOSPC;
+				break;
+			}
+		} else {
+			rcu_read_lock();
+			ob[nr_got] = bch2_bucket_alloc(c, ca, RESERVE_none,
+					       false, cl);
+			rcu_read_unlock();
+			if (IS_ERR(ob[nr_got])) {
+				ret = cl ? -EAGAIN : -ENOSPC;
+				break;
+			}
+
+			bu[nr_got] = ob[nr_got]->bucket;
+		}
 	}
 
+	if (!nr_got)
+		goto err_unblock;
+
 	/*
 	 * We may be called from the device add path, before the new device has
 	 * actually been added to the running filesystem:
@@ -813,51 +840,16 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
 	swap(new_buckets,	ja->buckets);
 	swap(new_bucket_seq,	ja->bucket_seq);
 
-	if (!new_fs)
-		spin_unlock(&c->journal.lock);
-
-	while (ja->nr < nr) {
-		struct open_bucket *ob = NULL;
-		unsigned pos;
-		long b;
-
-		if (new_fs) {
-			b = bch2_bucket_alloc_new_fs(ca);
-			if (b < 0) {
-				ret = -ENOSPC;
-				goto err;
-			}
-		} else {
-			rcu_read_lock();
-			ob = bch2_bucket_alloc(c, ca, RESERVE_none,
-					       false, cl);
-			rcu_read_unlock();
-			if (IS_ERR(ob)) {
-				ret = cl ? -EAGAIN : -ENOSPC;
-				goto err;
-			}
-
-			b = ob->bucket;
-		}
+	for (i = 0; i < nr_got; i++) {
+		unsigned pos = ja->discard_idx ?: ja->nr;
+		long b = bu[i];
 
-		if (c)
-			spin_lock(&c->journal.lock);
-
-		/*
-		 * XXX
-		 * For resize at runtime, we should be writing the new
-		 * superblock before inserting into the journal array
-		 */
-
-		pos = ja->discard_idx ?: ja->nr;
 		__array_insert_item(ja->buckets,		ja->nr, pos);
 		__array_insert_item(ja->bucket_seq,		ja->nr, pos);
-		__array_insert_item(journal_buckets->buckets,	ja->nr, pos);
 		ja->nr++;
 
 		ja->buckets[pos] = b;
 		ja->bucket_seq[pos] = 0;
-		journal_buckets->buckets[pos] = cpu_to_le64(b);
 
 		if (pos <= ja->discard_idx)
 			ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
@@ -867,29 +859,56 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
 			ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
 		if (pos <= ja->cur_idx)
 			ja->cur_idx = (ja->cur_idx + 1) % ja->nr;
+	}
 
-		if (c)
-			spin_unlock(&c->journal.lock);
+	ret = bch2_journal_buckets_to_sb(c, ca);
+	if (ret) {
+		/* Revert: */
+		swap(new_buckets,	ja->buckets);
+		swap(new_bucket_seq,	ja->bucket_seq);
+		ja->nr			= old_nr;
+		ja->discard_idx		= old_discard_idx;
+		ja->dirty_idx_ondisk	= old_dirty_idx_ondisk;
+		ja->dirty_idx		= old_dirty_idx;
+		ja->cur_idx		= old_cur_idx;
+	}
+
+	if (!new_fs)
+		spin_unlock(&c->journal.lock);
 
-		if (!new_fs) {
+	if (c)
+		bch2_journal_unblock(&c->journal);
+
+	if (ret)
+		goto err;
+
+	if (!new_fs) {
+		for (i = 0; i < nr_got; i++) {
 			ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_NOFAIL,
 				bch2_trans_mark_metadata_bucket(&trans, ca,
-						b, BCH_DATA_journal,
+						bu[i], BCH_DATA_journal,
 						ca->mi.bucket_size));
-
-			bch2_open_bucket_put(c, ob);
-
-			if (ret)
+			if (ret) {
+				bch2_fs_inconsistent(c, "error marking new journal buckets: %i", ret);
 				goto err;
+			}
 		}
 	}
 err:
-	bch2_sb_resize_journal(&ca->disk_sb,
-		ja->nr + sizeof(*journal_buckets) / sizeof(u64));
+	if (ob && !new_fs)
+		for (i = 0; i < nr_got; i++)
+			bch2_open_bucket_put(c, ob[i]);
+
 	kfree(new_bucket_seq);
 	kfree(new_buckets);
+	kfree(ob);
+	kfree(bu);
 
 	return ret;
+err_unblock:
+	if (c)
+		bch2_journal_unblock(&c->journal);
+	goto err;
 }
 
 /*
@@ -902,11 +921,15 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
 	struct journal_device *ja = &ca->journal;
 	struct closure cl;
 	unsigned current_nr;
-	int ret;
+	int ret = 0;
+
+	/* don't handle reducing nr of buckets yet: */
+	if (nr < ja->nr)
+		return 0;
 
 	closure_init_stack(&cl);
 
-	do {
+	while (ja->nr != nr && (ret == 0 || ret == -EAGAIN)) {
 		struct disk_reservation disk_res = { 0, 0 };
 
 		closure_sync(&cl);
@@ -934,7 +957,7 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
 		if (ja->nr != current_nr)
 			bch2_write_super(c);
 		mutex_unlock(&c->sb_lock);
-	} while (ret == -EAGAIN);
+	}
 
 	return ret;
 }
@@ -942,6 +965,7 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
 int bch2_dev_journal_alloc(struct bch_dev *ca)
 {
 	unsigned nr;
+	int ret;
 
 	if (dynamic_fault("bcachefs:add:journal_alloc"))
 		return -ENOMEM;
@@ -958,7 +982,15 @@ int bch2_dev_journal_alloc(struct bch_dev *ca)
 		     min(1 << 13,
 			 (1 << 24) / ca->mi.bucket_size));
 
-	return __bch2_set_nr_journal_buckets(ca, nr, true, NULL);
+	if (ca->fs)
+		mutex_lock(&ca->fs->sb_lock);
+
+	ret = __bch2_set_nr_journal_buckets(ca, nr, true, NULL);
+
+	if (ca->fs)
+		mutex_unlock(&ca->fs->sb_lock);
+
+	return ret;
 }
 
 /* startup/shutdown: */
@@ -1103,9 +1135,20 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 	struct journal_device *ja = &ca->journal;
 	struct bch_sb_field_journal *journal_buckets =
 		bch2_sb_get_journal(sb);
+	struct bch_sb_field_journal_v2 *journal_buckets_v2 =
+		bch2_sb_get_journal_v2(sb);
 	unsigned i, nr_bvecs;
 
-	ja->nr = bch2_nr_journal_buckets(journal_buckets);
+	ja->nr = 0;
+
+	if (journal_buckets_v2) {
+		unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
+
+		for (i = 0; i < nr; i++)
+			ja->nr += le64_to_cpu(journal_buckets_v2->d[i].nr);
+	} else if (journal_buckets) {
+		ja->nr = bch2_nr_journal_buckets(journal_buckets);
+	}
 
 	ja->bucket_seq = kcalloc(ja->nr, sizeof(u64), GFP_KERNEL);
 	if (!ja->bucket_seq)
@@ -1123,8 +1166,18 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 	if (!ja->buckets)
 		return -ENOMEM;
 
-	for (i = 0; i < ja->nr; i++)
-		ja->buckets[i] = le64_to_cpu(journal_buckets->buckets[i]);
+	if (journal_buckets_v2) {
+		unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
+		unsigned j, dst = 0;
+
+		for (i = 0; i < nr; i++)
+			for (j = 0; j < le64_to_cpu(journal_buckets_v2->d[i].nr); j++)
+				ja->buckets[dst++] =
+					le64_to_cpu(journal_buckets_v2->d[i].start) + j;
+	} else if (journal_buckets) {
+		for (i = 0; i < ja->nr; i++)
+			ja->buckets[i] = le64_to_cpu(journal_buckets->buckets[i]);
+	}
 
 	return 0;
 }
diff --git a/fs/bcachefs/journal_sb.c b/fs/bcachefs/journal_sb.c
new file mode 100644
index 000000000000..6d984313d4b5
--- /dev/null
+++ b/fs/bcachefs/journal_sb.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "journal_sb.h"
+#include "darray.h"
+
+#include <linux/sort.h>
+
+/* BCH_SB_FIELD_journal: */
+
+static int u64_cmp(const void *_l, const void *_r)
+{
+	const u64 *l = _l;
+	const u64 *r = _r;
+
+	return cmp_int(*l, *r);
+}
+
+static int bch2_sb_journal_validate(struct bch_sb *sb,
+				    struct bch_sb_field *f,
+				    struct printbuf *err)
+{
+	struct bch_sb_field_journal *journal = field_to_type(f, journal);
+	struct bch_member *m = bch2_sb_get_members(sb)->members + sb->dev_idx;
+	int ret = -EINVAL;
+	unsigned nr;
+	unsigned i;
+	u64 *b;
+
+	nr = bch2_nr_journal_buckets(journal);
+	if (!nr)
+		return 0;
+
+	b = kmalloc_array(sizeof(u64), nr, GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	for (i = 0; i < nr; i++)
+		b[i] = le64_to_cpu(journal->buckets[i]);
+
+	sort(b, nr, sizeof(u64), u64_cmp, NULL);
+
+	if (!b[0]) {
+		pr_buf(err, "journal bucket at sector 0");
+		goto err;
+	}
+
+	if (b[0] < le16_to_cpu(m->first_bucket)) {
+		pr_buf(err, "journal bucket %llu before first bucket %u",
+		       b[0], le16_to_cpu(m->first_bucket));
+		goto err;
+	}
+
+	if (b[nr - 1] >= le64_to_cpu(m->nbuckets)) {
+		pr_buf(err, "journal bucket %llu past end of device (nbuckets %llu)",
+		       b[nr - 1], le64_to_cpu(m->nbuckets));
+		goto err;
+	}
+
+	for (i = 0; i + 1 < nr; i++)
+		if (b[i] == b[i + 1]) {
+			pr_buf(err, "duplicate journal buckets %llu", b[i]);
+			goto err;
+		}
+
+	ret = 0;
+err:
+	kfree(b);
+	return ret;
+}
+
+static void bch2_sb_journal_to_text(struct printbuf *out, struct bch_sb *sb,
+				    struct bch_sb_field *f)
+{
+	struct bch_sb_field_journal *journal = field_to_type(f, journal);
+	unsigned i, nr = bch2_nr_journal_buckets(journal);
+
+	pr_buf(out, "Buckets: ");
+	for (i = 0; i < nr; i++)
+		pr_buf(out, " %llu", le64_to_cpu(journal->buckets[i]));
+	pr_newline(out);
+}
+
+const struct bch_sb_field_ops bch_sb_field_ops_journal = {
+	.validate	= bch2_sb_journal_validate,
+	.to_text	= bch2_sb_journal_to_text,
+};
+
+struct u64_range {
+	u64	start;
+	u64	end;
+};
+
+static int u64_range_cmp(const void *_l, const void *_r)
+{
+	const struct u64_range *l = _l;
+	const struct u64_range *r = _r;
+
+	return cmp_int(l->start, r->start);
+}
+
+static int bch2_sb_journal_v2_validate(struct bch_sb *sb,
+				    struct bch_sb_field *f,
+				    struct printbuf *err)
+{
+	struct bch_sb_field_journal_v2 *journal = field_to_type(f, journal_v2);
+	struct bch_member *m = bch2_sb_get_members(sb)->members + sb->dev_idx;
+	int ret = -EINVAL;
+	unsigned nr;
+	unsigned i;
+	struct u64_range *b;
+
+	nr = bch2_sb_field_journal_v2_nr_entries(journal);
+	if (!nr)
+		return 0;
+
+	b = kmalloc_array(sizeof(*b), nr, GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	for (i = 0; i < nr; i++) {
+		b[i].start = le64_to_cpu(journal->d[i].start);
+		b[i].end = b[i].start + le64_to_cpu(journal->d[i].nr);
+	}
+
+	sort(b, nr, sizeof(*b), u64_range_cmp, NULL);
+
+	if (!b[0].start) {
+		pr_buf(err, "journal bucket at sector 0");
+		goto err;
+	}
+
+	if (b[0].start < le16_to_cpu(m->first_bucket)) {
+		pr_buf(err, "journal bucket %llu before first bucket %u",
+		       b[0].start, le16_to_cpu(m->first_bucket));
+		goto err;
+	}
+
+	if (b[nr - 1].end > le64_to_cpu(m->nbuckets)) {
+		pr_buf(err, "journal bucket %llu past end of device (nbuckets %llu)",
+		       b[nr - 1].end - 1, le64_to_cpu(m->nbuckets));
+		goto err;
+	}
+
+	for (i = 0; i + 1 < nr; i++) {
+		if (b[i].end > b[i + 1].start) {
+			pr_buf(err, "duplicate journal buckets in ranges %llu-%llu, %llu-%llu",
+			       b[i].start, b[i].end, b[i + 1].start, b[i + 1].end);
+			goto err;
+		}
+	}
+
+	ret = 0;
+err:
+	kfree(b);
+	return ret;
+}
+
+static void bch2_sb_journal_v2_to_text(struct printbuf *out, struct bch_sb *sb,
+				    struct bch_sb_field *f)
+{
+	struct bch_sb_field_journal_v2 *journal = field_to_type(f, journal_v2);
+	unsigned i, nr = bch2_sb_field_journal_v2_nr_entries(journal);
+
+	pr_buf(out, "Buckets: ");
+	for (i = 0; i < nr; i++)
+		pr_buf(out, " %llu-%llu",
+		       le64_to_cpu(journal->d[i].start),
+		       le64_to_cpu(journal->d[i].start) + le64_to_cpu(journal->d[i].nr));
+	pr_newline(out);
+}
+
+const struct bch_sb_field_ops bch_sb_field_ops_journal_v2 = {
+	.validate	= bch2_sb_journal_v2_validate,
+	.to_text	= bch2_sb_journal_v2_to_text,
+};
+
+int bch2_journal_buckets_to_sb(struct bch_fs *c, struct bch_dev *ca)
+{
+	struct journal_device *ja = &ca->journal;
+	struct bch_sb_field_journal_v2 *j;
+	unsigned i, dst = 0, nr = 1;
+
+	if (c)
+		lockdep_assert_held(&c->sb_lock);
+
+	if (!ja->nr) {
+		bch2_sb_field_delete(&ca->disk_sb, BCH_SB_FIELD_journal);
+		bch2_sb_field_delete(&ca->disk_sb, BCH_SB_FIELD_journal_v2);
+		return 0;
+	}
+
+	for (i = 0; i + 1 < ja->nr; i++)
+		if (ja->buckets[i] + 1 != ja->buckets[i + 1])
+			nr++;
+
+	j = bch2_sb_resize_journal_v2(&ca->disk_sb,
+				 (sizeof(*j) + sizeof(j->d[0]) * nr) / sizeof(u64));
+	if (!j)
+		return -ENOSPC;
+
+	bch2_sb_field_delete(&ca->disk_sb, BCH_SB_FIELD_journal);
+
+	j->d[dst].start = le64_to_cpu(ja->buckets[0]);
+	j->d[dst].nr	= le64_to_cpu(1);
+
+	for (i = 1; i < ja->nr; i++) {
+		if (ja->buckets[i] == ja->buckets[i - 1] + 1) {
+			le64_add_cpu(&j->d[dst].nr, 1);
+		} else {
+			dst++;
+			j->d[dst].start = le64_to_cpu(ja->buckets[i]);
+			j->d[dst].nr	= le64_to_cpu(1);
+		}
+	}
+
+	BUG_ON(dst + 1 != nr);
+
+	return 0;
+}
diff --git a/fs/bcachefs/journal_sb.h b/fs/bcachefs/journal_sb.h
new file mode 100644
index 000000000000..a39192e9f6f4
--- /dev/null
+++ b/fs/bcachefs/journal_sb.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "super-io.h"
+#include "vstructs.h"
+
+static inline unsigned bch2_nr_journal_buckets(struct bch_sb_field_journal *j)
+{
+	return j
+		? (__le64 *) vstruct_end(&j->field) - j->buckets
+		: 0;
+}
+
+static inline unsigned bch2_sb_field_journal_v2_nr_entries(struct bch_sb_field_journal_v2 *j)
+{
+	if (!j)
+		return 0;
+
+	return (struct bch_sb_field_journal_v2_entry *) vstruct_end(&j->field) - &j->d[0];
+}
+
+extern const struct bch_sb_field_ops bch_sb_field_ops_journal;
+extern const struct bch_sb_field_ops bch_sb_field_ops_journal_v2;
+
+int bch2_journal_buckets_to_sb(struct bch_fs *, struct bch_dev *);
diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index 5c87c7308274..bc845c42768e 100644
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -10,6 +10,7 @@
 #include "io.h"
 #include "journal.h"
 #include "journal_io.h"
+#include "journal_sb.h"
 #include "journal_seq_blacklist.h"
 #include "replicas.h"
 #include "quota.h"
@@ -459,7 +460,7 @@ static void __copy_super(struct bch_sb_handle *dst_handle, struct bch_sb *src)
 	memcpy(dst->compat,	src->compat,	sizeof(dst->compat));
 
 	for (i = 0; i < BCH_SB_FIELD_NR; i++) {
-		if (i == BCH_SB_FIELD_journal)
+		if ((1U << i) & BCH_SINGLE_DEVICE_SB_FIELDS)
 			continue;
 
 		src_f = bch2_sb_field_get(src, i);
@@ -929,85 +930,6 @@ void __bch2_check_set_feature(struct bch_fs *c, unsigned feat)
 	mutex_unlock(&c->sb_lock);
 }
 
-/* BCH_SB_FIELD_journal: */
-
-static int u64_cmp(const void *_l, const void *_r)
-{
-	u64 l = *((const u64 *) _l), r = *((const u64 *) _r);
-
-	return l < r ? -1 : l > r ? 1 : 0;
-}
-
-static int bch2_sb_journal_validate(struct bch_sb *sb,
-				    struct bch_sb_field *f,
-				    struct printbuf *err)
-{
-	struct bch_sb_field_journal *journal = field_to_type(f, journal);
-	struct bch_member *m = bch2_sb_get_members(sb)->members + sb->dev_idx;
-	int ret = -EINVAL;
-	unsigned nr;
-	unsigned i;
-	u64 *b;
-
-	nr = bch2_nr_journal_buckets(journal);
-	if (!nr)
-		return 0;
-
-	b = kmalloc_array(sizeof(u64), nr, GFP_KERNEL);
-	if (!b)
-		return -ENOMEM;
-
-	for (i = 0; i < nr; i++)
-		b[i] = le64_to_cpu(journal->buckets[i]);
-
-	sort(b, nr, sizeof(u64), u64_cmp, NULL);
-
-	if (!b[0]) {
-		pr_buf(err, "journal bucket at sector 0");
-		goto err;
-	}
-
-	if (b[0] < le16_to_cpu(m->first_bucket)) {
-		pr_buf(err, "journal bucket %llu before first bucket %u",
-		       b[0], le16_to_cpu(m->first_bucket));
-		goto err;
-	}
-
-	if (b[nr - 1] >= le64_to_cpu(m->nbuckets)) {
-		pr_buf(err, "journal bucket %llu past end of device (nbuckets %llu)",
-		       b[nr - 1], le64_to_cpu(m->nbuckets));
-		goto err;
-	}
-
-	for (i = 0; i + 1 < nr; i++)
-		if (b[i] == b[i + 1]) {
-			pr_buf(err, "duplicate journal buckets %llu", b[i]);
-			goto err;
-		}
-
-	ret = 0;
-err:
-	kfree(b);
-	return ret;
-}
-
-static void bch2_sb_journal_to_text(struct printbuf *out, struct bch_sb *sb,
-				    struct bch_sb_field *f)
-{
-	struct bch_sb_field_journal *journal = field_to_type(f, journal);
-	unsigned i, nr = bch2_nr_journal_buckets(journal);
-
-	pr_buf(out, "Buckets: ");
-	for (i = 0; i < nr; i++)
-		pr_buf(out, " %llu", le64_to_cpu(journal->buckets[i]));
-	pr_newline(out);
-}
-
-static const struct bch_sb_field_ops bch_sb_field_ops_journal = {
-	.validate	= bch2_sb_journal_validate,
-	.to_text	= bch2_sb_journal_to_text,
-};
-
 /* BCH_SB_FIELD_members: */
 
 static int bch2_sb_members_validate(struct bch_sb *sb,
diff --git a/fs/bcachefs/super-io.h b/fs/bcachefs/super-io.h
index ccd6fe7fdf29..bed61a01e4be 100644
--- a/fs/bcachefs/super-io.h
+++ b/fs/bcachefs/super-io.h
@@ -75,15 +75,6 @@ static inline void bch2_check_set_feature(struct bch_fs *c, unsigned feat)
 		__bch2_check_set_feature(c, feat);
 }
 
-/* BCH_SB_FIELD_journal: */
-
-static inline unsigned bch2_nr_journal_buckets(struct bch_sb_field_journal *j)
-{
-	return j
-		? (__le64 *) vstruct_end(&j->field) - j->buckets
-		: 0;
-}
-
 /* BCH_SB_FIELD_members: */
 
 static inline bool bch2_member_exists(struct bch_member *m)