// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "btree_iter.h"
#include "error.h"
#include "journal.h"
#include "recovery_passes.h"
#include "super.h"
#include "thread_with_file.h"

#define FSCK_ERR_RATELIMIT_NR	10

bool bch2_inconsistent_error(struct bch_fs *c)
{
	set_bit(BCH_FS_error, &c->flags);

	switch (c->opts.errors) {
	case BCH_ON_ERROR_continue:
		return false;
	case BCH_ON_ERROR_fix_safe:
	case BCH_ON_ERROR_ro:
		if (bch2_fs_emergency_read_only(c))
			bch_err(c, "inconsistency detected - emergency read only at journal seq %llu",
				journal_cur_seq(&c->journal));
		return true;
	case BCH_ON_ERROR_panic:
		panic(bch2_fmt(c, "panic after error"));
		return true;
	default:
		BUG();
	}
}

int bch2_topology_error(struct bch_fs *c)
{
	set_bit(BCH_FS_topology_error, &c->flags);
	if (!test_bit(BCH_FS_fsck_running, &c->flags)) {
		bch2_inconsistent_error(c);
		return -BCH_ERR_btree_need_topology_repair;
	} else {
		return bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology) ?:
			-BCH_ERR_btree_node_read_validate_error;
	}
}

void bch2_fatal_error(struct bch_fs *c)
{
	if (bch2_fs_emergency_read_only(c))
		bch_err(c, "fatal error - emergency read only");
}

void bch2_io_error_work(struct work_struct *work)
{
	struct bch_dev *ca = container_of(work, struct bch_dev, io_error_work);
	struct bch_fs *c = ca->fs;
	bool dev;

	down_write(&c->state_lock);
	dev = bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_ro,
				    BCH_FORCE_IF_DEGRADED);
	if (dev
	    ? __bch2_dev_set_state(c, ca, BCH_MEMBER_STATE_ro,
				  BCH_FORCE_IF_DEGRADED)
	    : bch2_fs_emergency_read_only(c))
		bch_err(ca,
			"too many IO errors, setting %s RO",
			dev ? "device" : "filesystem");
	up_write(&c->state_lock);
}

void bch2_io_error(struct bch_dev *ca, enum bch_member_error_type type)
{
	atomic64_inc(&ca->errors[type]);
	//queue_work(system_long_wq, &ca->io_error_work);
}

enum ask_yn {
	YN_NO,
	YN_YES,
	YN_ALLNO,
	YN_ALLYES,
};

static enum ask_yn parse_yn_response(char *buf)
{
	buf = strim(buf);

	if (strlen(buf) == 1)
		switch (buf[0]) {
		case 'n':
			return YN_NO;
		case 'y':
			return YN_YES;
		case 'N':
			return YN_ALLNO;
		case 'Y':
			return YN_ALLYES;
		}
	return -1;
}

#ifdef __KERNEL__
static enum ask_yn bch2_fsck_ask_yn(struct bch_fs *c, struct btree_trans *trans)
{
	struct stdio_redirect *stdio = c->stdio;

	if (c->stdio_filter && c->stdio_filter != current)
		stdio = NULL;

	if (!stdio)
		return YN_NO;

	if (trans)
		bch2_trans_unlock(trans);

	unsigned long unlock_long_at = trans ? jiffies + HZ * 2 : 0;
	darray_char line = {};
	int ret;

	do {
		unsigned long t;
		bch2_print(c, " (y,n, or Y,N for all errors of this type) ");
rewait:
		t = unlock_long_at
			? max_t(long, unlock_long_at - jiffies, 0)
			: MAX_SCHEDULE_TIMEOUT;

		int r = bch2_stdio_redirect_readline_timeout(stdio, &line, t);
		if (r == -ETIME) {
			bch2_trans_unlock_long(trans);
			unlock_long_at = 0;
			goto rewait;
		}

		if (r < 0) {
			ret = YN_NO;
			break;
		}

		darray_last(line) = '\0';
	} while ((ret = parse_yn_response(line.data)) < 0);

	darray_exit(&line);
	return ret;
}
#else

#include "tools-util.h"

static enum ask_yn bch2_fsck_ask_yn(struct bch_fs *c, struct btree_trans *trans)
{
	char *buf = NULL;
	size_t buflen = 0;
	int ret;

	do {
		fputs(" (y,n, or Y,N for all errors of this type) ", stdout);
		fflush(stdout);

		if (getline(&buf, &buflen, stdin) < 0)
			die("error reading from standard input");
	} while ((ret = parse_yn_response(buf)) < 0);

	free(buf);
	return ret;
}

#endif

static struct fsck_err_state *fsck_err_get(struct bch_fs *c, const char *fmt)
{
	struct fsck_err_state *s;

	if (!test_bit(BCH_FS_fsck_running, &c->flags))
		return NULL;

	list_for_each_entry(s, &c->fsck_error_msgs, list)
		if (s->fmt == fmt) {
			/*
			 * move it to the head of the list: repeated fsck errors
			 * are common
			 */
			list_move(&s->list, &c->fsck_error_msgs);
			return s;
		}

	s = kzalloc(sizeof(*s), GFP_NOFS);
	if (!s) {
		if (!c->fsck_alloc_msgs_err)
			bch_err(c, "kmalloc err, cannot ratelimit fsck errs");
		c->fsck_alloc_msgs_err = true;
		return NULL;
	}

	INIT_LIST_HEAD(&s->list);
	s->fmt = fmt;
	list_add(&s->list, &c->fsck_error_msgs);
	return s;
}

/* s/fix?/fixing/ s/recreate?/recreating/ */
static void prt_actioning(struct printbuf *out, const char *action)
{
	unsigned len = strlen(action);

	BUG_ON(action[len - 1] != '?');
	--len;

	if (action[len - 1] == 'e')
		--len;

	prt_bytes(out, action, len);
	prt_str(out, "ing");
}

static const u8 fsck_flags_extra[] = {
#define x(t, n, flags)		[BCH_FSCK_ERR_##t] = flags,
	BCH_SB_ERRS()
#undef x
};

int __bch2_fsck_err(struct bch_fs *c,
		  struct btree_trans *trans,
		  enum bch_fsck_flags flags,
		  enum bch_sb_error_id err,
		  const char *fmt, ...)
{
	struct fsck_err_state *s = NULL;
	va_list args;
	bool print = true, suppressing = false, inconsistent = false;
	struct printbuf buf = PRINTBUF, *out = &buf;
	int ret = -BCH_ERR_fsck_ignore;
	const char *action_orig = "fix?", *action = action_orig;

	might_sleep();

	if (!WARN_ON(err >= ARRAY_SIZE(fsck_flags_extra)))
		flags |= fsck_flags_extra[err];

	if (!c)
		c = trans->c;

	WARN_ON(!trans && bch2_current_has_btree_trans(c));

	if ((flags & FSCK_CAN_FIX) &&
	    test_bit(err, c->sb.errors_silent))
		return -BCH_ERR_fsck_fix;

	bch2_sb_error_count(c, err);

	va_start(args, fmt);
	prt_vprintf(out, fmt, args);
	va_end(args);

	/* Custom fix/continue/recreate/etc.? */
	if (out->buf[out->pos - 1] == '?') {
		const char *p = strrchr(out->buf, ',');
		if (p) {
			out->pos = p - out->buf;
			action = kstrdup(p + 2, GFP_KERNEL);
			if (!action) {
				ret = -ENOMEM;
				goto err;
			}
		}
	}

	mutex_lock(&c->fsck_error_msgs_lock);
	s = fsck_err_get(c, fmt);
	if (s) {
		/*
		 * We may be called multiple times for the same error on
		 * transaction restart - this memoizes instead of asking the user
		 * multiple times for the same error:
		 */
		if (s->last_msg && !strcmp(buf.buf, s->last_msg)) {
			ret = s->ret;
			mutex_unlock(&c->fsck_error_msgs_lock);
			goto err;
		}

		kfree(s->last_msg);
		s->last_msg = kstrdup(buf.buf, GFP_KERNEL);
		if (!s->last_msg) {
			mutex_unlock(&c->fsck_error_msgs_lock);
			ret = -ENOMEM;
			goto err;
		}

		if (c->opts.ratelimit_errors &&
		    !(flags & FSCK_NO_RATELIMIT) &&
		    s->nr >= FSCK_ERR_RATELIMIT_NR) {
			if (s->nr == FSCK_ERR_RATELIMIT_NR)
				suppressing = true;
			else
				print = false;
		}

		s->nr++;
	}

#ifdef BCACHEFS_LOG_PREFIX
	if (!strncmp(fmt, "bcachefs:", 9))
		prt_printf(out, bch2_log_msg(c, ""));
#endif

	if ((flags & FSCK_CAN_FIX) &&
	    (flags & FSCK_AUTOFIX) &&
	    (c->opts.errors == BCH_ON_ERROR_continue ||
	     c->opts.errors == BCH_ON_ERROR_fix_safe)) {
		prt_str(out, ", ");
		prt_actioning(out, action);
		ret = -BCH_ERR_fsck_fix;
	} else if (!test_bit(BCH_FS_fsck_running, &c->flags)) {
		if (c->opts.errors != BCH_ON_ERROR_continue ||
		    !(flags & (FSCK_CAN_FIX|FSCK_CAN_IGNORE))) {
			prt_str(out, ", shutting down");
			inconsistent = true;
			ret = -BCH_ERR_fsck_errors_not_fixed;
		} else if (flags & FSCK_CAN_FIX) {
			prt_str(out, ", ");
			prt_actioning(out, action);
			ret = -BCH_ERR_fsck_fix;
		} else {
			prt_str(out, ", continuing");
			ret = -BCH_ERR_fsck_ignore;
		}
	} else if (c->opts.fix_errors == FSCK_FIX_exit) {
		prt_str(out, ", exiting");
		ret = -BCH_ERR_fsck_errors_not_fixed;
	} else if (flags & FSCK_CAN_FIX) {
		int fix = s && s->fix
			? s->fix
			: c->opts.fix_errors;

		if (fix == FSCK_FIX_ask) {
			prt_str(out, ", ");
			prt_str(out, action);

			if (bch2_fs_stdio_redirect(c))
				bch2_print(c, "%s", out->buf);
			else
				bch2_print_string_as_lines(KERN_ERR, out->buf);
			print = false;

			int ask = bch2_fsck_ask_yn(c, trans);

			if (trans) {
				ret = bch2_trans_relock(trans);
				if (ret) {
					mutex_unlock(&c->fsck_error_msgs_lock);
					goto err;
				}
			}

			if (ask >= YN_ALLNO && s)
				s->fix = ask == YN_ALLNO
					? FSCK_FIX_no
					: FSCK_FIX_yes;

			ret = ask & 1
				? -BCH_ERR_fsck_fix
				: -BCH_ERR_fsck_ignore;
		} else if (fix == FSCK_FIX_yes ||
			   (c->opts.nochanges &&
			    !(flags & FSCK_CAN_IGNORE))) {
			prt_str(out, ", ");
			prt_actioning(out, action);
			ret = -BCH_ERR_fsck_fix;
		} else {
			prt_str(out, ", not ");
			prt_actioning(out, action);
		}
	} else if (flags & FSCK_NEED_FSCK) {
		prt_str(out, " (run fsck to correct)");
	} else {
		prt_str(out, " (repair unimplemented)");
	}

	if (ret == -BCH_ERR_fsck_ignore &&
	    (c->opts.fix_errors == FSCK_FIX_exit ||
	     !(flags & FSCK_CAN_IGNORE)))
		ret = -BCH_ERR_fsck_errors_not_fixed;

	if (print) {
		if (bch2_fs_stdio_redirect(c))
			bch2_print(c, "%s\n", out->buf);
		else
			bch2_print_string_as_lines(KERN_ERR, out->buf);
	}

	if (test_bit(BCH_FS_fsck_running, &c->flags) &&
	    (ret != -BCH_ERR_fsck_fix &&
	     ret != -BCH_ERR_fsck_ignore))
		bch_err(c, "Unable to continue, halting");
	else if (suppressing)
		bch_err(c, "Ratelimiting new instances of previous error");

	if (s)
		s->ret = ret;

	mutex_unlock(&c->fsck_error_msgs_lock);

	if (inconsistent)
		bch2_inconsistent_error(c);

	if (ret == -BCH_ERR_fsck_fix) {
		set_bit(BCH_FS_errors_fixed, &c->flags);
	} else {
		set_bit(BCH_FS_errors_not_fixed, &c->flags);
		set_bit(BCH_FS_error, &c->flags);
	}
err:
	if (action != action_orig)
		kfree(action);
	printbuf_exit(&buf);
	return ret;
}

void bch2_flush_fsck_errs(struct bch_fs *c)
{
	struct fsck_err_state *s, *n;

	mutex_lock(&c->fsck_error_msgs_lock);

	list_for_each_entry_safe(s, n, &c->fsck_error_msgs, list) {
		if (s->ratelimited && s->last_msg)
			bch_err(c, "Saw %llu errors like:\n    %s", s->nr, s->last_msg);

		list_del(&s->list);
		kfree(s->last_msg);
		kfree(s);
	}

	mutex_unlock(&c->fsck_error_msgs_lock);
}