// SPDX-License-Identifier: GPL-2.0

#include <linux/kernel.h>
#include <linux/fs_parser.h>

#include "bcachefs.h"
#include "opts.h"

#include "alloc/background.h"
#include "alloc/disk_groups.h"

#include "btree/update.h"

#include "data/compress.h"
#include "data/copygc.h"
#include "data/reconcile/work.h"

#include "init/dev.h"
#include "init/error.h"
#include "init/passes.h"

#include "sb/io.h"

#include "util/util.h"

/*
 * fs/fs_parser.c marked the standard bool_names static in 7.1, so carry our
 * own copy. Same six tokens as the original — strict, no looser parsing.
 */
static const struct constant_table bch2_bool_names[] = {
	{ "0",		false },
	{ "1",		true  },
	{ "false",	false },
	{ "no",		false },
	{ "true",	true  },
	{ "yes",	true  },
	{ },
};

#define x(t, n, ...) [n] = #t,

const char * const bch2_error_actions[] = {
	BCH_ERROR_ACTIONS()
	NULL
};

const char * const bch2_degraded_actions[] = {
	BCH_DEGRADED_ACTIONS()
	NULL
};

const char * const bch2_fsck_fix_opts[] = {
	BCH_FIX_ERRORS_OPTS()
	NULL
};

const char * const bch2_version_upgrade_opts[] = {
	BCH_VERSION_UPGRADE_OPTS()
	NULL
};

const char * const bch2_sb_features[] = {
	BCH_SB_FEATURES()
	NULL
};

const char * const bch2_sb_compat[] = {
	BCH_SB_COMPAT()
	NULL
};

const char * const __bch2_btree_ids[] = {
	BCH_BTREE_IDS()
	NULL
};

const char * const __bch2_csum_types[] = {
	BCH_CSUM_TYPES()
	NULL
};

const char * const __bch2_csum_opts[] = {
	BCH_CSUM_OPTS()
	NULL
};

const char * const __bch2_compression_types[] = {
	BCH_COMPRESSION_TYPES()
	NULL
};

const char * const bch2_compression_opts[] = {
	BCH_COMPRESSION_OPTS()
	NULL
};

const char * const __bch2_str_hash_types[] = {
	BCH_STR_HASH_TYPES()
	NULL
};

const char * const bch2_str_hash_opts[] = {
	BCH_STR_HASH_OPTS()
	NULL
};

const char * const __bch2_data_types[] = {
	BCH_DATA_TYPES()
	NULL
};

const char * const bch2_member_states[] = {
	BCH_MEMBER_STATES()
	NULL
};

static const char * const __bch2_jset_entry_types[] = {
	BCH_JSET_ENTRY_TYPES()
	NULL
};

static const char * const __bch2_fs_usage_types[] = {
	BCH_FS_USAGE_TYPES()
	NULL
};

const char * const __bch2_reconcile_accounting_types[] = {
	BCH_RECONCILE_ACCOUNTING()
	NULL
};

static const char * const __bch2_key_type_error_reasons[] = {
	KEY_TYPE_ERRORS()
	NULL
};

const char * const bch2_scrub_journal_opts[] = {
	BCH_SCRUB_JOURNAL_OPTS()
	NULL
};

#undef x

static void prt_str_opt_boundscheck(struct printbuf *out, const char * const opts[],
				    unsigned nr, const char *type, unsigned idx)
{
	if (idx < nr)
		prt_str(out, opts[idx]);
	else
		prt_printf(out, "(unknown %s %u)", type, idx);
}

#define PRT_STR_OPT_BOUNDSCHECKED(name, type)					\
void bch2_prt_##name(struct printbuf *out, type t)				\
{										\
	prt_str_opt_boundscheck(out, __bch2_##name##s, ARRAY_SIZE(__bch2_##name##s) - 1, #name, t);\
}

PRT_STR_OPT_BOUNDSCHECKED(jset_entry_type,	enum bch_jset_entry_type);
PRT_STR_OPT_BOUNDSCHECKED(fs_usage_type,	enum bch_fs_usage_type);
PRT_STR_OPT_BOUNDSCHECKED(data_type,		enum bch_data_type);
PRT_STR_OPT_BOUNDSCHECKED(csum_opt,		enum bch_csum_opt);
PRT_STR_OPT_BOUNDSCHECKED(csum_type,		enum bch_csum_type);
PRT_STR_OPT_BOUNDSCHECKED(compression_type,	enum bch_compression_type);
PRT_STR_OPT_BOUNDSCHECKED(str_hash_type,	enum bch_str_hash_type);
PRT_STR_OPT_BOUNDSCHECKED(reconcile_accounting_type,	enum bch_reconcile_accounting_type);
PRT_STR_OPT_BOUNDSCHECKED(key_type_error_reason,enum bch_key_type_errors);

static int bch2_opt_fix_errors_parse(struct bch_fs *c, const char *val, u64 *res,
				     struct printbuf *err)
{
	if (!val) {
		*res = FSCK_FIX_yes;
	} else {
		int ret = match_string(bch2_fsck_fix_opts, -1, val);

		if (ret < 0 && err)
			prt_str(err, "fix_errors: invalid selection");
		if (ret < 0)
			return ret;
		*res = ret;
	}

	return 0;
}

static __cold void bch2_opt_fix_errors_to_text(struct printbuf *out,
					struct bch_fs *c,
					struct bch_sb *sb,
					u64 v)
{
	prt_str(out, bch2_fsck_fix_opts[v]);
}

#define bch2_opt_fix_errors (struct bch_opt_fn) {	\
	.parse = bch2_opt_fix_errors_parse,		\
	.to_text = bch2_opt_fix_errors_to_text,		\
}

const char * const bch2_d_types[BCH_DT_MAX] = {
	[DT_UNKNOWN]	= "unknown",
	[DT_FIFO]	= "fifo",
	[DT_CHR]	= "chr",
	[DT_DIR]	= "dir",
	[DT_BLK]	= "blk",
	[DT_REG]	= "reg",
	[DT_LNK]	= "lnk",
	[DT_SOCK]	= "sock",
	[DT_WHT]	= "whiteout",
	[DT_SUBVOL]	= "subvol",
};

void bch2_opts_apply(struct bch_opts *dst, struct bch_opts src)
{
#define x(_name, ...)						\
	if (opt_defined(src, _name))					\
		opt_set(*dst, _name, src._name);

	BCH_OPTS()
#undef x
}

bool bch2_opt_defined_by_id(const struct bch_opts *opts, enum bch_opt_id id)
{
	switch (id) {
#define x(_name, ...)						\
	case Opt_##_name:						\
		return opt_defined(*opts, _name);
	BCH_OPTS()
#undef x
	default:
		BUG();
	}
}

u64 bch2_opt_get_by_id(const struct bch_opts *opts, enum bch_opt_id id)
{
	switch (id) {
#define x(_name, ...)						\
	case Opt_##_name:						\
		return opts->_name;
	BCH_OPTS()
#undef x
	default:
		BUG();
	}
}

void bch2_opt_set_by_id(struct bch_opts *opts, enum bch_opt_id id, u64 v)
{
	switch (id) {
#define x(_name, ...)						\
	case Opt_##_name:						\
		opt_set(*opts, _name, v);				\
		break;
	BCH_OPTS()
#undef x
	default:
		BUG();
	}
}

/* dummy option, for options that aren't stored in the superblock */
typedef u64 (*sb_opt_get_fn)(const struct bch_sb *);
typedef void (*sb_opt_set_fn)(struct bch_sb *, u64);
typedef u64 (*member_opt_get_fn)(const struct bch_member *);
typedef void (*member_opt_set_fn)(struct bch_member *, u64);
typedef u64 (*ext_opt_get_fn)(const struct bch_sb_field_ext *);
typedef void (*ext_opt_set_fn)(struct bch_sb_field_ext *, u64);

__maybe_unused static const sb_opt_get_fn	BCH2_NO_SB_OPT = NULL;
__maybe_unused static const sb_opt_set_fn	SET_BCH2_NO_SB_OPT = NULL;
__maybe_unused static const member_opt_get_fn	BCH2_NO_MEMBER_OPT = NULL;
__maybe_unused static const member_opt_set_fn	SET_BCH2_NO_MEMBER_OPT = NULL;
__maybe_unused static const ext_opt_get_fn	BCH2_NO_EXT_OPT = NULL;
__maybe_unused static const ext_opt_set_fn	SET_BCH2_NO_EXT_OPT = NULL;

#define type_compatible_or_null(_p, _type)				\
	__builtin_choose_expr(						\
		__builtin_types_compatible_p(typeof(_p), typeof(_type)), _p, NULL)

const struct bch_option bch2_opt_table[] = {
/* .min and .max are both inclusive bounds; a value is valid iff min <= v <= max */
#define OPT_BOOL()		.type = BCH_OPT_BOOL, .min = 0, .max = 1
#define OPT_UINT(_min, _max)	.type = BCH_OPT_UINT,			\
				.min = _min, .max = _max
#define OPT_STR(_choices)	.type = BCH_OPT_STR,			\
				.min = 0, .max = ARRAY_SIZE(_choices) - 2, \
				.choices = _choices
#define OPT_STR_NOLIMIT(_choices)	.type = BCH_OPT_STR,		\
				.min = 0, .max = U64_MAX,		\
				.choices = _choices
#define OPT_BITFIELD(_choices)	OPT_BITFIELD_MASK(_choices, U64_MAX)
#define OPT_BITFIELD_MASK(_choices, _choices_allowed_mask)	.type = BCH_OPT_BITFIELD,\
				.choices = _choices,			\
				.choices_allowed_mask = _choices_allowed_mask
#define OPT_FN(_fn)		.type = BCH_OPT_FN, .fn	= _fn

#define x(_name, _bits, _flags, _type, _sb_opt, _default, _hint, _help)	\
	[Opt_##_name] = {						\
		.attr.name	= #_name,				\
		.attr.mode	= (_flags) & OPT_RUNTIME ? 0644 : 0444,	\
		.flags		= _flags,				\
		.hint		= _hint,				\
		.help		= _help,				\
		.get_sb		= type_compatible_or_null(_sb_opt,	*BCH2_NO_SB_OPT),	\
		.set_sb		= type_compatible_or_null(SET_##_sb_opt,*SET_BCH2_NO_SB_OPT),	\
		.get_member	= type_compatible_or_null(_sb_opt,	*BCH2_NO_MEMBER_OPT),	\
		.set_member	= type_compatible_or_null(SET_##_sb_opt,*SET_BCH2_NO_MEMBER_OPT),\
		.get_ext	= type_compatible_or_null(_sb_opt,	*BCH2_NO_EXT_OPT),	\
		.set_ext	= type_compatible_or_null(SET_##_sb_opt,*SET_BCH2_NO_EXT_OPT),	\
		_type							\
	},

	BCH_OPTS()
#undef x
};

int bch2_opt_lookup(const char *name)
{
	const struct bch_option *i;

	for (i = bch2_opt_table;
	     i < bch2_opt_table + ARRAY_SIZE(bch2_opt_table);
	     i++)
		if (!strcmp(name, i->attr.name))
			return i - bch2_opt_table;

	return -1;
}

struct opt_synonym {
	const char	*s1, *s2;
};

static const struct opt_synonym bch2_opt_synonyms[] = {
	{ "quota",	"usrquota" },
};

static int bch2_mount_opt_lookup(const char *name)
{
	const struct opt_synonym *i;

	for (i = bch2_opt_synonyms;
	     i < bch2_opt_synonyms + ARRAY_SIZE(bch2_opt_synonyms);
	     i++)
		if (!strcmp(name, i->s1))
			name = i->s2;

	return bch2_opt_lookup(name);
}

struct opt_val_synonym {
	const char	*opt, *v1, *v2;
};

static const struct opt_val_synonym bch2_opt_val_synonyms[] = {
	{ "degraded",	"true",		"yes" },
	{ "degraded",	"false",	"no"  },
	{ "degraded",	"1",		"yes" },
	{ "degraded",	"0",		"no"  },
};

static const char *bch2_opt_val_synonym_lookup(const char *opt, const char *val)
{
	const struct opt_val_synonym *i;

	for (i = bch2_opt_val_synonyms;
	     i < bch2_opt_val_synonyms + ARRAY_SIZE(bch2_opt_val_synonyms);
	     i++)
		if (!strcmp(opt, i->opt) && !strcmp(val, i->v1))
			return i->v2;

	return val;
}

int bch2_opt_validate(const struct bch_option *opt, u64 v, struct printbuf *err)
{
	if (v < opt->min) {
		if (err)
			prt_printf(err, "%s: too small (min %llu)",
			       opt->attr.name, opt->min);
		return -BCH_ERR_ERANGE_option_too_small;
	}

	if (opt->max && v > opt->max) {
		if (err)
			prt_printf(err, "%s: too big (max %llu)",
			       opt->attr.name, opt->max);
		return -BCH_ERR_ERANGE_option_too_big;
	}

	if ((opt->flags & OPT_SB_FIELD_SECTORS) && (v & 511)) {
		if (err)
			prt_printf(err, "%s: not a multiple of 512",
			       opt->attr.name);
		return -BCH_ERR_opt_parse_error;
	}

	if ((opt->flags & OPT_MUST_BE_POW_2) && !is_power_of_2(v)) {
		if (err)
			prt_printf(err, "%s: must be a power of two",
			       opt->attr.name);
		return -BCH_ERR_opt_parse_error;
	}

	if (opt->fn.validate)
		return opt->fn.validate(v, err);

	return 0;
}

int bch2_opt_parse(struct bch_fs *c,
		   const struct bch_option *opt,
		   const char *val, u64 *res,
		   struct printbuf *err)
{
	ssize_t ret;

	if (err)
		printbuf_indent_add_nextline(err, 2);

	switch (opt->type) {
	case BCH_OPT_BOOL:
		if (!val)
			val = "1";

		ret = lookup_constant(bch2_bool_names, val, -BCH_ERR_option_not_bool);
		if (ret != -BCH_ERR_option_not_bool) {
			*res = ret;
		} else {
			if (err)
				prt_printf(err, "%s: must be bool", opt->attr.name);
			return ret;
		}
		break;
	case BCH_OPT_UINT:
		if (!val) {
			prt_printf(err, "%s: required value",
				   opt->attr.name);
			return -BCH_ERR_EINVAL_opt_parse_uint_required;
		}

		if (*val != '-') {
			ret = opt->flags & OPT_HUMAN_READABLE
			    ? bch2_strtou64_h(val, res)
			    : kstrtou64(val, 10, res);
		} else {
			prt_printf(err, "%s: must be a non-negative number", opt->attr.name);
			return -BCH_ERR_option_negative;
		}

		if (ret < 0) {
			if (err)
				prt_printf(err, "%s: must be a number",
					   opt->attr.name);
			return ret;
		}
		break;
	case BCH_OPT_STR:
		if (!val) {
			prt_printf(err, "%s: required value",
				   opt->attr.name);
			return -BCH_ERR_EINVAL_opt_parse_str_required;
		}

		ret = match_string(opt->choices, -1, val);
		if (ret < 0) {
			if (err)
				prt_printf(err, "%s: invalid selection",
					   opt->attr.name);
			return ret;
		}

		*res = ret;
		break;
	case BCH_OPT_BITFIELD: {
		s64 v = bch2_read_flag_list_mask(val, opt->choices, opt->choices_allowed_mask);
		if (v < 0)
			return v;
		*res = v;
		break;
	}
	case BCH_OPT_FN:
		ret = opt->fn.parse(c, val, res, err);

		if (ret == -BCH_ERR_option_needs_open_fs)
			return ret;

		if (ret < 0) {
			if (err)
				prt_printf(err, "%s: parse error",
					   opt->attr.name);
			return ret;
		}
	}

	return bch2_opt_validate(opt, *res, err);
}

__cold void bch2_opt_to_text(struct printbuf *out,
		      struct bch_fs *c, struct bch_sb *sb,
		      const struct bch_option *opt, u64 v,
		      unsigned flags)
{
	if (flags & OPT_SHOW_MOUNT_STYLE) {
		if (opt->type == BCH_OPT_BOOL) {
			prt_printf(out, "%s%s",
			       v ? "" : "no",
			       opt->attr.name);
			return;
		}

		prt_printf(out, "%s=", opt->attr.name);
	}

	switch (opt->type) {
	case BCH_OPT_BOOL:
	case BCH_OPT_UINT:
		if (opt->flags & OPT_HUMAN_READABLE)
			prt_human_readable_u64(out, v);
		else
			prt_printf(out, "%lli", v);
		break;
	case BCH_OPT_STR:
		if (v < opt->min || v > opt->max)
			prt_printf(out, "(invalid option %lli)", v);
		else if (flags & OPT_SHOW_FULL_LIST)
			prt_string_option(out, opt->choices, v);
		else
			prt_str(out, opt->choices[v]);
		break;
	case BCH_OPT_BITFIELD:
		prt_bitflags(out, opt->choices, v);
		break;
	case BCH_OPT_FN:
		opt->fn.to_text(out, c, sb, v);
		break;
	default:
		BUG();
	}
}

__cold void bch2_opts_to_text(struct printbuf *out,
		       struct bch_opts opts,
		       struct bch_fs *c, struct bch_sb *sb,
		       struct bch_opts_mask *mask,
		       unsigned show_mask, unsigned hide_mask,
		       unsigned flags)
{
	bool first = true;

	for (enum bch_opt_id i = 0; i < bch2_opts_nr; i++) {
		const struct bch_option *opt = &bch2_opt_table[i];

		if ((opt->flags & hide_mask) || !(opt->flags & show_mask))
			continue;

		if (mask && !test_bit(i, mask->d))
			continue;

		u64 v = bch2_opt_get_by_id(&opts, i);
		if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
			continue;

		if (!first)
			prt_char(out, ',');
		first = false;

		bch2_opt_to_text(out, c, sb, opt, v, flags);
	}
}

static int reconcile_scan_bracket(struct bch_fs *c, struct reconcile_scan s, bool post,
				  struct opt_change_scope *scope)
{
	return post
		? bch2_set_reconcile_needs_scan_post(c, s)
		: bch2_set_reconcile_needs_scan_pre(c, s, scope);
}

static int opt_hook_io(struct bch_fs *c, struct bch_dev *ca, u64 inum, enum bch_opt_id id,
		       u64 v, bool post, struct opt_change_scope *scope)
{
	if (!test_bit(BCH_FS_started, &c->flags))
		return 0;

	switch (id) {
	case Opt_foreground_target:
	case Opt_background_target:
	case Opt_promote_target:
	case Opt_compression:
	case Opt_background_compression:
	case Opt_data_checksum:
	case Opt_data_replicas:
	case Opt_erasure_code:
	case Opt_nocow: {
		struct reconcile_scan s = {
			.type = !inum ? RECONCILE_SCAN_fs : RECONCILE_SCAN_inum,
			.inum = inum,
		};

		try(reconcile_scan_bracket(c, s, post, scope));
		break;
	}
	case Opt_metadata_target:
	case Opt_metadata_checksum:
	case Opt_metadata_replicas:
		try(reconcile_scan_bracket(c,
			(struct reconcile_scan) { .type = RECONCILE_SCAN_metadata, .dev = inum }, post, scope));
		break;
	case Opt_durability:
		if (!post && v > ca->mi.durability)
			try(bch2_set_reconcile_needs_scan(c,
				(struct reconcile_scan) { .type = RECONCILE_SCAN_pending}, false));

		try(reconcile_scan_bracket(c,
			(struct reconcile_scan) { .type = RECONCILE_SCAN_device, .dev = inum }, post, scope));
		break;
	case Opt_ec_max_data_blocks:
		/*
		 * Cap participates in stripe.can_widen (via
		 * stripe_widen_target_nr_data); bracket the change with a
		 * stripes scan so existing stripes converge to the new
		 * target.
		 */
		try(reconcile_scan_bracket(c,
			(struct reconcile_scan) { .type = RECONCILE_SCAN_stripes }, post, scope));
		break;
	case Opt_label:
		/*
		 * Refresh the cpu label tree before the scan wakes: reconcile
		 * reads the group devs masks. Errors here (ENOMEM) just leave
		 * the cpu copy stale until the next superblock swap:
		 */
		if (post) {
			scoped_guard(mutex, &c->sb_lock)
				bch_err_fn(c, bch2_sb_disk_groups_to_cpu(c));
		}

		try(reconcile_scan_bracket(c,
			(struct reconcile_scan) { .type = RECONCILE_SCAN_pending }, post, scope));
		break;
	default:
		break;
	}

	return 0;
}

int bch2_opt_hook_pre_set(struct bch_fs *c, struct bch_dev *ca, u64 inum, enum bch_opt_id id, u64 v,
			  bool change, struct opt_change_scope *scope)
{
	switch (id) {
	case Opt_state:
		if (ca)
			return bch2_dev_set_state(c, ca, v, BCH_FORCE_IF_DEGRADED, NULL);
		break;

	case Opt_compression:
	case Opt_background_compression:
		try(bch2_check_set_has_compressed_data(c, v));
		break;
	case Opt_erasure_code:
		if (v)
			bch2_check_set_feature(c, BCH_FEATURE_ec);
		break;
	case Opt_casefold_disabled:
		if (v && (c->sb.features & BIT_ULL(BCH_FEATURE_casefolding))) {
			bch_err(c, "cannot mount with casefolding disabled: casefolding already in use");
			return bch_err_throw(c, casefolding_in_use);
		}
		break;
	default:
		break;
	}

	if (change)
		try(opt_hook_io(c, ca, inum, id, v, false, scope));

	return 0;
}

int bch2_opts_hooks_pre_set(struct bch_fs *c)
{
	for (unsigned i = 0; i < bch2_opts_nr; i++)
		try(bch2_opt_hook_pre_set(c, NULL, 0, i, bch2_opt_get_by_id(&c->opts, i), false, NULL));

	return 0;
}

void bch2_opt_hook_post_set(struct bch_fs *c, struct bch_dev *ca, u64 inum,
			    enum bch_opt_id id, u64 v)
{
	if (test_bit(BCH_FS_started, &c->flags)) {
		CLASS(printbuf, buf)();
		prt_printf(&buf, "opt change: %s=", bch2_opt_table[id].attr.name);
		bch2_opt_to_text(&buf, c, c->disk_sb.sb, &bch2_opt_table[id], v, 0);
		if (ca)
			prt_printf(&buf, " dev %u", ca->dev_idx);
		if (inum)
			prt_printf(&buf, " inum %llu", inum);
		bch2_fs_log_msg(c, "%s", buf.buf);
	}

	opt_hook_io(c, ca, inum, id, v, true, NULL);

	switch (id) {
	case Opt_reconcile_enabled:
		bch2_reconcile_wakeup(c);
		break;
	case Opt_copygc_enabled:
		bch2_copygc_wakeup(c);
		break;
	case Opt_discard:
		if (!ca) {
			guard(memalloc_flags)(PF_MEMALLOC_NOFS);
			guard(mutex)(&c->sb_lock);
			for_each_member_device(c, ca) {
				struct bch_member *m =
					bch2_members_v2_get_mut(ca->disk_sb.sb, ca->dev_idx);
				SET_BCH_MEMBER_DISCARD(m, c->opts.discard);
			}

			bch2_write_super(c);
		}
		break;
	case Opt_durability:
		if (test_bit(BCH_FS_rw, &c->flags) &&
		    ca &&
		    bch2_dev_is_online(ca) &&
		    ca->mi.state == BCH_MEMBER_STATE_rw) {
			scoped_guard(rcu)
				bch2_dev_allocator_set_rw(c, ca, true);
			bch2_recalc_capacity(c);
		}
		break;
	case Opt_version_upgrade:
		/*
		 * XXX: in the future we'll likely want to do compatible
		 * upgrades at runtime as well, but right now there's nothing
		 * that does that:
		 */
		if (v == BCH_VERSION_UPGRADE_incompatible)
			bch2_sb_upgrade_incompat(c);
		break;
	case Opt_read_only:
		bch2_reconcile_wakeup(c);
		break;
	case Opt_btree_cache_shrinker_seeks: {
		struct bch_fs_btree_cache *bc = &c->btree.cache;

		if (bc->live[0].shrink)
			bc->live[0].shrink->seeks = v;
		if (bc->live[1].shrink)
			bc->live[1].shrink->seeks = v * 4;
		break;
	}
	default:
		break;
	}
}

int bch2_parse_one_mount_opt(struct bch_fs *c, struct bch_opts *opts,
			     struct printbuf *parse_later,
			     const char *name, const char *val,
			     struct printbuf *err)
{
	u64 v;
	int ret, id;

	id = bch2_mount_opt_lookup(name);

	/* Check for the form "noopt", negation of a boolean opt: */
	if (id < 0 &&
	    !val &&
	    !strncmp("no", name, 2)) {
		id = bch2_mount_opt_lookup(name + 2);
		val = "0";
	}

	/* Unknown options are ignored: */
	if (id < 0)
		return 0;

	/* must have a value for synonym lookup - but OPT_FN is weird */
	if (!val && bch2_opt_table[id].type != BCH_OPT_FN)
		val = "1";

	val = bch2_opt_val_synonym_lookup(name, val);

	if (!(bch2_opt_table[id].flags & OPT_MOUNT) &&
	    !(bch2_opt_table[id].flags & OPT_MOUNT_OLD))
		return -BCH_ERR_option_name;

	if ((id == Opt_usrquota ||
	     id == Opt_grpquota) &&
	    !IS_ENABLED(CONFIG_BCACHEFS_QUOTA))
		return -BCH_ERR_option_name;

	ret = bch2_opt_parse(c, &bch2_opt_table[id], val, &v, err);
	if (ret == -BCH_ERR_option_needs_open_fs) {
		if (parse_later) {
			prt_printf(parse_later, "%s=%s,", name, val);
			if (parse_later->allocation_failure)
				return -ENOMEM;
		}

		return 0;
	}

	if (ret < 0)
		return ret;

	if (bch2_opt_table[id].flags & OPT_MOUNT_OLD) {
		pr_err("option %s may no longer be specified at mount time; set via sysfs opts dir",
		       bch2_opt_table[id].attr.name);
		return 0;
	}

	if (opts)
		bch2_opt_set_by_id(opts, id, v);

	return 0;
}

int bch2_parse_mount_opts(struct bch_fs *c, struct bch_opts *opts,
			  struct printbuf *parse_later, char *options,
			  bool ignore_unknown)
{
	if (!options)
		return 0;

	/*
	 * sys_fsconfig() is now occasionally providing us with option lists
	 * starting with a comma - weird.
	 */
	if (*options == ',')
		options++;

	char *copied_opts __free(kfree) = kstrdup(options, GFP_KERNEL);
	if (!copied_opts)
		return -ENOMEM;

	char *optstr = copied_opts;
	char *opt, *name, *val;
	int ret = 0;

	while ((opt = strsep(&optstr, ",")) != NULL) {
		if (!*opt)
			continue;

		name	= strsep(&opt, "=");
		val	= opt;

		CLASS(printbuf, err)();
		ret = bch2_parse_one_mount_opt(c, opts, parse_later, name, val, &err);
		if (ret == -BCH_ERR_option_name && ignore_unknown)
			ret = 0;
		if (ret) {
			pr_err("Error parsing option %s", err.buf);
			break;
		}
	}

	return ret;
}

u64 bch2_opt_from_sb(struct bch_sb *sb, enum bch_opt_id id, int dev_idx)
{
	const struct bch_option *opt = bch2_opt_table + id;
	u64 v;

	if (dev_idx < 0) {
		if (opt->get_sb) {
			v = opt->get_sb(sb);
		} else if (opt->get_ext) {
			const struct bch_sb_field_ext *ext = bch2_sb_field_get(sb, ext);
			v = ext ? opt->get_ext(ext) : 0;
		} else {
			v = 0;
		}
	} else {
		if (WARN(!bch2_member_exists(sb, dev_idx),
			 "tried to set device option %s on nonexistent device %i",
			 opt->attr.name, dev_idx))
			return 0;

		struct bch_member m = bch2_sb_member_get(sb, dev_idx);
		v = opt->get_member(&m);
	}

	if (opt->flags & OPT_SB_FIELD_ONE_BIAS)
		--v;

	if (opt->flags & OPT_SB_FIELD_ILOG2)
		v = 1ULL << v;

	if (opt->flags & OPT_SB_FIELD_SECTORS)
		v <<= 9;

	return v;
}

/*
 * Initial options from superblock - here we don't want any options undefined,
 * any options the superblock doesn't specify are set to 0:
 */
int bch2_opts_from_sb(struct bch_opts *opts, struct bch_sb *sb)
{
	for (unsigned id = 0; id < bch2_opts_nr; id++) {
		const struct bch_option *opt = bch2_opt_table + id;

		if (opt->get_sb || opt->get_ext)
			bch2_opt_set_by_id(opts, id, bch2_opt_from_sb(sb, id, -1));
	}

	return 0;
}

bool __bch2_opt_set_sb(struct bch_sb *sb, int dev_idx,
		       const struct bch_option *opt, u64 v)
{
	bool changed = false;

	if (opt->flags & OPT_SB_FIELD_SECTORS)
		v >>= 9;

	if (opt->flags & OPT_SB_FIELD_ILOG2)
		v = ilog2(v);

	if (opt->flags & OPT_SB_FIELD_ONE_BIAS)
		v++;

	if ((opt->flags & OPT_FS) && dev_idx < 0) {
		if (opt->set_sb) {
			changed = v != opt->get_sb(sb);
			opt->set_sb(sb, v);
		} else if (opt->set_ext) {
			struct bch_sb_field_ext *ext = bch2_sb_field_get(sb, ext);
			changed = v != opt->get_ext(ext);
			opt->set_ext(ext, v);
		}
	}

	if ((opt->flags & OPT_DEVICE) && opt->set_member && dev_idx >= 0) {
		if (WARN(!bch2_member_exists(sb, dev_idx),
			 "tried to set device option %s on nonexistent device %i",
			 opt->attr.name, dev_idx))
			return false;

		struct bch_member *m = bch2_members_v2_get_mut(sb, dev_idx);
		changed = v != opt->get_member(m);
		opt->set_member(m, v);
	}

	return changed;
}

bool bch2_opt_set_sb(struct bch_fs *c, struct bch_dev *ca,
		     const struct bch_option *opt, u64 v)
{
	guard(memalloc_flags)(PF_MEMALLOC_NOFS);
	guard(mutex)(&c->sb_lock);
	bool changed = __bch2_opt_set_sb(c->disk_sb.sb, ca ? ca->dev_idx : -1, opt, v);
	if (changed)
		bch2_write_super(c);
	return changed;
}

const __maybe_unused struct bch_opts bch2_opts_default = {
#define x(_name, _bits, _mode, _type, _sb_opt, _default, ...)		\
	._name##_defined = true,					\
	._name = _default,						\

	BCH_OPTS()
#undef x
};

/* io opts: */

void bch2_inode_opts_get(struct bch_fs *c, struct bch_inode_opts *ret, bool metadata)
{
	memset(ret, 0, sizeof(*ret));

#define x(_name, _bits)	ret->_name = c->opts._name,
	BCH_INODE_OPTS()
#undef x

	ret->change_cookie = c->opt_change_cookie;

	if (metadata) {
		ret->background_target	= c->opts.metadata_target ?: c->opts.foreground_target;
		ret->data_replicas	= c->opts.metadata_replicas;
		ret->data_checksum	= c->opts.metadata_checksum;
		ret->compression	= 0;
		ret->background_compression = 0;
		ret->erasure_code	= false;
	} else {
		bch2_io_opts_fixups(ret);
	}
}

bool bch2_opt_is_inode_opt(enum bch_opt_id id)
{
	static const enum bch_opt_id inode_opt_list[] = {
#define x(_name, _bits)	Opt_##_name,
	BCH_INODE_OPTS()
#undef x
	};
	unsigned i;

	for (i = 0; i < ARRAY_SIZE(inode_opt_list); i++)
		if (inode_opt_list[i] == id)
			return true;

	return false;
}

__cold void bch2_inode_opts_to_text(struct printbuf *out, struct bch_fs *c, struct bch_inode_opts opts)
{
	bool first = true;

#define x(_name, _bits)							\
	if (!first)							\
		prt_char(out, ',');					\
	first = false;							\
	prt_printf(out, "%s=", bch2_opt_table[Opt_##_name].attr.name);	\
	bch2_opt_to_text(out, c, c->disk_sb.sb, &bch2_opt_table[Opt_##_name], opts._name, 0);
	BCH_INODE_OPTS()
#undef x
}

void bch2_opt_change_unlock(struct bch_fs *c)
{
	BUG_ON(!(c->opt_change_cookie & 1));
	c->opt_change_cookie++;
	mutex_unlock(&c->opt_change_lock);
}

void bch2_opt_change_lock(struct bch_fs *c)
{
	mutex_lock(&c->opt_change_lock);
	BUG_ON(c->opt_change_cookie & 1);
	c->opt_change_cookie++;
}
