1 files changed, 494 insertions, 0 deletions

diff --git a/fs/bcachefs/disk_groups.c b/fs/bcachefs/disk_groups.c
new file mode 100644
index 000000000000..48f472a384f1
--- /dev/null
+++ b/fs/bcachefs/disk_groups.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "bcachefs.h"
+#include "disk_groups.h"
+#include "super-io.h"
+
+#include <linux/sort.h>
+
+static int group_cmp(const void *_l, const void *_r)
+{
+	const struct bch_disk_group *l = _l;
+	const struct bch_disk_group *r = _r;
+
+	return ((BCH_GROUP_DELETED(l) > BCH_GROUP_DELETED(r)) -
+		(BCH_GROUP_DELETED(l) < BCH_GROUP_DELETED(r))) ?:
+		((BCH_GROUP_PARENT(l) > BCH_GROUP_PARENT(r)) -
+		 (BCH_GROUP_PARENT(l) < BCH_GROUP_PARENT(r))) ?:
+		strncmp(l->label, r->label, sizeof(l->label));
+}
+
+static const char *bch2_sb_disk_groups_validate(struct bch_sb *sb,
+						struct bch_sb_field *f)
+{
+	struct bch_sb_field_disk_groups *groups =
+		field_to_type(f, disk_groups);
+	struct bch_disk_group *g, *sorted = NULL;
+	struct bch_sb_field_members *mi;
+	struct bch_member *m;
+	unsigned i, nr_groups, len;
+	const char *err = NULL;
+
+	mi		= bch2_sb_get_members(sb);
+	groups		= bch2_sb_get_disk_groups(sb);
+	nr_groups	= disk_groups_nr(groups);
+
+	for (m = mi->members;
+	     m < mi->members + sb->nr_devices;
+	     m++) {
+		unsigned g;
+
+		if (!BCH_MEMBER_GROUP(m))
+			continue;
+
+		g = BCH_MEMBER_GROUP(m) - 1;
+
+		if (g >= nr_groups ||
+		    BCH_GROUP_DELETED(&groups->entries[g]))
+			return "disk has invalid group";
+	}
+
+	if (!nr_groups)
+		return NULL;
+
+	for (g = groups->entries;
+	     g < groups->entries + nr_groups;
+	     g++) {
+		if (BCH_GROUP_DELETED(g))
+			continue;
+
+		len = strnlen(g->label, sizeof(g->label));
+		if (!len) {
+			err = "group with empty label";
+			goto err;
+		}
+	}
+
+	sorted = kmalloc_array(nr_groups, sizeof(*sorted), GFP_KERNEL);
+	if (!sorted)
+		return "cannot allocate memory";
+
+	memcpy(sorted, groups->entries, nr_groups * sizeof(*sorted));
+	sort(sorted, nr_groups, sizeof(*sorted), group_cmp, NULL);
+
+	for (i = 0; i + 1 < nr_groups; i++)
+		if (!BCH_GROUP_DELETED(sorted + i) &&
+		    !group_cmp(sorted + i, sorted + i + 1)) {
+			err = "duplicate groups";
+			goto err;
+		}
+
+	err = NULL;
+err:
+	kfree(sorted);
+	return err;
+}
+
+static size_t bch2_sb_disk_groups_to_text(char *buf, size_t size,
+					struct bch_sb *sb,
+					struct bch_sb_field *f)
+{
+	char *out = buf, *end = buf + size;
+	struct bch_sb_field_disk_groups *groups =
+		field_to_type(f, disk_groups);
+	struct bch_disk_group *g;
+	unsigned nr_groups = disk_groups_nr(groups);
+
+	for (g = groups->entries;
+	     g < groups->entries + nr_groups;
+	     g++) {
+		if (g != groups->entries)
+			out += scnprintf(out, end - out, " ");
+
+		if (BCH_GROUP_DELETED(g))
+			out += scnprintf(out, end - out, "[deleted]");
+		else
+			out += scnprintf(out, end - out,
+					 "[parent %llu name %s]",
+					 BCH_GROUP_PARENT(g),
+					 g->label);
+	}
+
+	return out - buf;
+}
+
+const struct bch_sb_field_ops bch_sb_field_ops_disk_groups = {
+	.validate	= bch2_sb_disk_groups_validate,
+	.to_text	= bch2_sb_disk_groups_to_text
+};
+
+int bch2_sb_disk_groups_to_cpu(struct bch_fs *c)
+{
+	struct bch_sb_field_members *mi;
+	struct bch_sb_field_disk_groups *groups;
+	struct bch_disk_groups_cpu *cpu_g, *old_g;
+	unsigned i, g, nr_groups;
+
+	lockdep_assert_held(&c->sb_lock);
+
+	mi		= bch2_sb_get_members(c->disk_sb.sb);
+	groups		= bch2_sb_get_disk_groups(c->disk_sb.sb);
+	nr_groups	= disk_groups_nr(groups);
+
+	if (!groups)
+		return 0;
+
+	cpu_g = kzalloc(sizeof(*cpu_g) +
+			sizeof(cpu_g->entries[0]) * nr_groups, GFP_KERNEL);
+	if (!cpu_g)
+		return -ENOMEM;
+
+	cpu_g->nr = nr_groups;
+
+	for (i = 0; i < nr_groups; i++) {
+		struct bch_disk_group *src	= &groups->entries[i];
+		struct bch_disk_group_cpu *dst	= &cpu_g->entries[i];
+
+		dst->deleted	= BCH_GROUP_DELETED(src);
+		dst->parent	= BCH_GROUP_PARENT(src);
+	}
+
+	for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
+		struct bch_member *m = mi->members + i;
+		struct bch_disk_group_cpu *dst =
+			&cpu_g->entries[BCH_MEMBER_GROUP(m)];
+
+		if (!bch2_member_exists(m))
+			continue;
+
+		g = BCH_MEMBER_GROUP(m);
+		while (g) {
+			dst = &cpu_g->entries[g - 1];
+			__set_bit(i, dst->devs.d);
+			g = dst->parent;
+		}
+	}
+
+	old_g = rcu_dereference_protected(c->disk_groups,
+				lockdep_is_held(&c->sb_lock));
+	rcu_assign_pointer(c->disk_groups, cpu_g);
+	if (old_g)
+		kfree_rcu(old_g, rcu);
+
+	return 0;
+}
+
+const struct bch_devs_mask *bch2_target_to_mask(struct bch_fs *c, unsigned target)
+{
+	struct target t = target_decode(target);
+
+	switch (t.type) {
+	case TARGET_NULL:
+		return NULL;
+	case TARGET_DEV: {
+		struct bch_dev *ca = t.dev < c->sb.nr_devices
+			? rcu_dereference(c->devs[t.dev])
+			: NULL;
+		return ca ? &ca->self : NULL;
+	}
+	case TARGET_GROUP: {
+		struct bch_disk_groups_cpu *g = rcu_dereference(c->disk_groups);
+
+		return t.group < g->nr && !g->entries[t.group].deleted
+			? &g->entries[t.group].devs
+			: NULL;
+	}
+	default:
+		BUG();
+	}
+}
+
+bool bch2_dev_in_target(struct bch_fs *c, unsigned dev, unsigned target)
+{
+	struct target t = target_decode(target);
+
+	switch (t.type) {
+	case TARGET_NULL:
+		return false;
+	case TARGET_DEV:
+		return dev == t.dev;
+	case TARGET_GROUP: {
+		struct bch_disk_groups_cpu *g;
+		const struct bch_devs_mask *m;
+		bool ret;
+
+		rcu_read_lock();
+		g = rcu_dereference(c->disk_groups);
+		m = t.group < g->nr && !g->entries[t.group].deleted
+			? &g->entries[t.group].devs
+			: NULL;
+
+		ret = m ? test_bit(dev, m->d) : false;
+		rcu_read_unlock();
+
+		return ret;
+	}
+	default:
+		BUG();
+	}
+}
+
+static int __bch2_disk_group_find(struct bch_sb_field_disk_groups *groups,
+				  unsigned parent,
+				  const char *name, unsigned namelen)
+{
+	unsigned i, nr_groups = disk_groups_nr(groups);
+
+	if (!namelen || namelen > BCH_SB_LABEL_SIZE)
+		return -EINVAL;
+
+	for (i = 0; i < nr_groups; i++) {
+		struct bch_disk_group *g = groups->entries + i;
+
+		if (BCH_GROUP_DELETED(g))
+			continue;
+
+		if (!BCH_GROUP_DELETED(g) &&
+		    BCH_GROUP_PARENT(g) == parent &&
+		    strnlen(g->label, sizeof(g->label)) == namelen &&
+		    !memcmp(name, g->label, namelen))
+			return i;
+	}
+
+	return -1;
+}
+
+static int __bch2_disk_group_add(struct bch_sb_handle *sb, unsigned parent,
+				 const char *name, unsigned namelen)
+{
+	struct bch_sb_field_disk_groups *groups =
+		bch2_sb_get_disk_groups(sb->sb);
+	unsigned i, nr_groups = disk_groups_nr(groups);
+	struct bch_disk_group *g;
+
+	if (!namelen || namelen > BCH_SB_LABEL_SIZE)
+		return -EINVAL;
+
+	for (i = 0;
+	     i < nr_groups && !BCH_GROUP_DELETED(&groups->entries[i]);
+	     i++)
+		;
+
+	if (i == nr_groups) {
+		unsigned u64s =
+			(sizeof(struct bch_sb_field_disk_groups) +
+			 sizeof(struct bch_disk_group) * (nr_groups + 1)) /
+			sizeof(u64);
+
+		groups = bch2_sb_resize_disk_groups(sb, u64s);
+		if (!groups)
+			return -ENOSPC;
+
+		nr_groups = disk_groups_nr(groups);
+	}
+
+	BUG_ON(i >= nr_groups);
+
+	g = &groups->entries[i];
+
+	memcpy(g->label, name, namelen);
+	if (namelen < sizeof(g->label))
+		g->label[namelen] = '\0';
+	SET_BCH_GROUP_DELETED(g, 0);
+	SET_BCH_GROUP_PARENT(g, parent);
+	SET_BCH_GROUP_DATA_ALLOWED(g, ~0);
+
+	return i;
+}
+
+int bch2_disk_path_find(struct bch_sb_handle *sb, const char *name)
+{
+	struct bch_sb_field_disk_groups *groups =
+		bch2_sb_get_disk_groups(sb->sb);
+	int v = -1;
+
+	do {
+		const char *next = strchrnul(name, '.');
+		unsigned len = next - name;
+
+		if (*next == '.')
+			next++;
+
+		v = __bch2_disk_group_find(groups, v + 1, name, len);
+		name = next;
+	} while (*name && v >= 0);
+
+	return v;
+}
+
+int bch2_disk_path_find_or_create(struct bch_sb_handle *sb, const char *name)
+{
+	struct bch_sb_field_disk_groups *groups;
+	unsigned parent = 0;
+	int v = -1;
+
+	do {
+		const char *next = strchrnul(name, '.');
+		unsigned len = next - name;
+
+		if (*next == '.')
+			next++;
+
+		groups = bch2_sb_get_disk_groups(sb->sb);
+
+		v = __bch2_disk_group_find(groups, parent, name, len);
+		if (v < 0)
+			v = __bch2_disk_group_add(sb, parent, name, len);
+		if (v < 0)
+			return v;
+
+		parent = v + 1;
+		name = next;
+	} while (*name && v >= 0);
+
+	return v;
+}
+
+int bch2_disk_path_print(struct bch_sb_handle *sb,
+			 char *buf, size_t len, unsigned v)
+{
+	char *out = buf, *end = out + len;
+	struct bch_sb_field_disk_groups *groups =
+		bch2_sb_get_disk_groups(sb->sb);
+	struct bch_disk_group *g;
+	unsigned nr = 0;
+	u16 path[32];
+
+	while (1) {
+		if (nr == ARRAY_SIZE(path))
+			goto inval;
+
+		if (v >= disk_groups_nr(groups))
+			goto inval;
+
+		g = groups->entries + v;
+
+		if (BCH_GROUP_DELETED(g))
+			goto inval;
+
+		path[nr++] = v;
+
+		if (!BCH_GROUP_PARENT(g))
+			break;
+
+		v = BCH_GROUP_PARENT(g) - 1;
+	}
+
+	while (nr) {
+		unsigned b = 0;
+
+		v = path[--nr];
+		g = groups->entries + v;
+
+		if (end != out)
+			b = min_t(size_t, end - out,
+				  strnlen(g->label, sizeof(g->label)));
+		memcpy(out, g->label, b);
+		if (b < end - out)
+			out[b] = '\0';
+		out += b;
+
+		if (nr)
+			out += scnprintf(out, end - out, ".");
+	}
+
+	return out - buf;
+inval:
+	return scnprintf(buf, len, "invalid group %u", v);
+}
+
+int bch2_dev_group_set(struct bch_fs *c, struct bch_dev *ca, const char *name)
+{
+	struct bch_member *mi;
+	int v = -1;
+
+	mutex_lock(&c->sb_lock);
+
+	if (!strlen(name) || !strcmp(name, "none"))
+		goto write_sb;
+
+	v = bch2_disk_path_find_or_create(&c->disk_sb, name);
+	if (v < 0) {
+		mutex_unlock(&c->sb_lock);
+		return v;
+	}
+
+write_sb:
+	mi = &bch2_sb_get_members(c->disk_sb.sb)->members[ca->dev_idx];
+	SET_BCH_MEMBER_GROUP(mi, v + 1);
+
+	bch2_write_super(c);
+	mutex_unlock(&c->sb_lock);
+
+	return 0;
+}
+
+int bch2_opt_target_parse(struct bch_fs *c, const char *buf, u64 *v)
+{
+	struct bch_dev *ca;
+	int g;
+
+	if (!strlen(buf) || !strcmp(buf, "none")) {
+		*v = 0;
+		return 0;
+	}
+
+	/* Is it a device? */
+	ca = bch2_dev_lookup(c, buf);
+	if (!IS_ERR(ca)) {
+		*v = dev_to_target(ca->dev_idx);
+		percpu_ref_put(&ca->ref);
+		return 0;
+	}
+
+	mutex_lock(&c->sb_lock);
+	g = bch2_disk_path_find(&c->disk_sb, buf);
+	mutex_unlock(&c->sb_lock);
+
+	if (g >= 0) {
+		*v = group_to_target(g);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+int bch2_opt_target_print(struct bch_fs *c, char *buf, size_t len, u64 v)
+{
+	struct target t = target_decode(v);
+	int ret;
+
+	switch (t.type) {
+	case TARGET_NULL:
+		return scnprintf(buf, len, "none");
+	case TARGET_DEV: {
+		struct bch_dev *ca;
+
+		rcu_read_lock();
+		ca = t.dev < c->sb.nr_devices
+			? rcu_dereference(c->devs[t.dev])
+			: NULL;
+
+		if (ca && percpu_ref_tryget(&ca->io_ref)) {
+			ret = scnprintf(buf, len, "/dev/%pg",
+					ca->disk_sb.bdev);
+			percpu_ref_put(&ca->io_ref);
+		} else if (ca) {
+			ret = scnprintf(buf, len, "offline device %u", t.dev);
+		} else {
+			ret = scnprintf(buf, len, "invalid device %u", t.dev);
+		}
+
+		rcu_read_unlock();
+		break;
+	}
+	case TARGET_GROUP:
+		mutex_lock(&c->sb_lock);
+		ret = bch2_disk_path_print(&c->disk_sb, buf, len, t.group);
+		mutex_unlock(&c->sb_lock);
+		break;
+	default:
+		BUG();
+	}
+
+	return ret;
+}