/*
   * Copyright (c) 2014 Red Hat, Inc.
   * All Rights Reserved.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it would be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write the Free Software Foundation,
   * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  
  #include "xfs.h"

  #include "xfs_shared.h"

  #include "xfs_format.h"

  #include "xfs_log_format.h"

  #include "xfs_trans_resv.h"

  #include "xfs_sysfs.h"

  #include "xfs_log.h"
  #include "xfs_log_priv.h"

  #include "xfs_stats.h"

  #include "xfs_mount.h"

  
  struct xfs_sysfs_attr {
  	struct attribute attr;

  	ssize_t (*show)(struct kobject *kobject, char *buf);
  	ssize_t (*store)(struct kobject *kobject, const char *buf,
  			 size_t count);

  };
  
  static inline struct xfs_sysfs_attr *
  to_attr(struct attribute *attr)
  {
  	return container_of(attr, struct xfs_sysfs_attr, attr);
  }
  
  #define XFS_SYSFS_ATTR_RW(name) \
  	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RW(name)
  #define XFS_SYSFS_ATTR_RO(name) \
  	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RO(name)

  #define XFS_SYSFS_ATTR_WO(name) \
  	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_WO(name)

  
  #define ATTR_LIST(name) &xfs_sysfs_attr_##name.attr

  STATIC ssize_t
  xfs_sysfs_object_show(
  	struct kobject		*kobject,
  	struct attribute	*attr,
  	char			*buf)
  {
  	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
  
  	return xfs_attr->show ? xfs_attr->show(kobject, buf) : 0;
  }
  
  STATIC ssize_t
  xfs_sysfs_object_store(
  	struct kobject		*kobject,
  	struct attribute	*attr,
  	const char		*buf,
  	size_t			count)
  {
  	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
  
  	return xfs_attr->store ? xfs_attr->store(kobject, buf, count) : 0;
  }
  
  static const struct sysfs_ops xfs_sysfs_ops = {
  	.show = xfs_sysfs_object_show,
  	.store = xfs_sysfs_object_store,
  };

  /*
   * xfs_mount kobject. The mp kobject also serves as the per-mount parent object
   * that is identified by the fsname under sysfs.
   */
  
  static inline struct xfs_mount *
  to_mp(struct kobject *kobject)
  {
  	struct xfs_kobj *kobj = to_kobj(kobject);
  
  	return container_of(kobj, struct xfs_mount, m_kobj);
  }

  static struct attribute *xfs_mp_attrs[] = {

  	NULL,
  };
  
  struct kobj_type xfs_mp_ktype = {
  	.release = xfs_sysfs_release,
  	.sysfs_ops = &xfs_sysfs_ops,
  	.default_attrs = xfs_mp_attrs,
  };

  #ifdef DEBUG
  /* debug */

  STATIC ssize_t

  bug_on_assert_store(
  	struct kobject		*kobject,
  	const char		*buf,
  	size_t			count)
  {
  	int			ret;
  	int			val;
  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;
  
  	if (val == 1)
  		xfs_globals.bug_on_assert = true;
  	else if (val == 0)
  		xfs_globals.bug_on_assert = false;
  	else
  		return -EINVAL;
  
  	return count;
  }
  
  STATIC ssize_t
  bug_on_assert_show(
  	struct kobject		*kobject,
  	char			*buf)
  {
  	return snprintf(buf, PAGE_SIZE, "%d
  ", xfs_globals.bug_on_assert ? 1 : 0);
  }
  XFS_SYSFS_ATTR_RW(bug_on_assert);
  
  STATIC ssize_t

  log_recovery_delay_store(

  	struct kobject	*kobject,

  	const char	*buf,

  	size_t		count)

  {
  	int		ret;
  	int		val;
  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;
  
  	if (val < 0 || val > 60)
  		return -EINVAL;
  
  	xfs_globals.log_recovery_delay = val;
  
  	return count;
  }
  
  STATIC ssize_t
  log_recovery_delay_show(

  	struct kobject	*kobject,
  	char		*buf)

  {
  	return snprintf(buf, PAGE_SIZE, "%d
  ", xfs_globals.log_recovery_delay);
  }
  XFS_SYSFS_ATTR_RW(log_recovery_delay);

  static struct attribute *xfs_dbg_attrs[] = {

  	ATTR_LIST(bug_on_assert),

  	ATTR_LIST(log_recovery_delay),

  	NULL,
  };

  struct kobj_type xfs_dbg_ktype = {
  	.release = xfs_sysfs_release,

  	.sysfs_ops = &xfs_sysfs_ops,

  	.default_attrs = xfs_dbg_attrs,
  };
  
  #endif /* DEBUG */

  /* stats */

  static inline struct xstats *
  to_xstats(struct kobject *kobject)
  {
  	struct xfs_kobj *kobj = to_kobj(kobject);
  
  	return container_of(kobj, struct xstats, xs_kobj);
  }

  STATIC ssize_t
  stats_show(

  	struct kobject	*kobject,
  	char		*buf)

  {

  	struct xstats	*stats = to_xstats(kobject);
  
  	return xfs_stats_format(stats->xs_stats, buf);

  }
  XFS_SYSFS_ATTR_RO(stats);
  
  STATIC ssize_t
  stats_clear_store(

  	struct kobject	*kobject,

  	const char	*buf,

  	size_t		count)

  {
  	int		ret;
  	int		val;

  	struct xstats	*stats = to_xstats(kobject);

  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;
  
  	if (val != 1)
  		return -EINVAL;

  
  	xfs_stats_clearall(stats->xs_stats);

  	return count;
  }
  XFS_SYSFS_ATTR_WO(stats_clear);
  
  static struct attribute *xfs_stats_attrs[] = {
  	ATTR_LIST(stats),
  	ATTR_LIST(stats_clear),
  	NULL,
  };

  struct kobj_type xfs_stats_ktype = {
  	.release = xfs_sysfs_release,

  	.sysfs_ops = &xfs_sysfs_ops,

  	.default_attrs = xfs_stats_attrs,
  };

  /* xlog */

  static inline struct xlog *
  to_xlog(struct kobject *kobject)
  {
  	struct xfs_kobj *kobj = to_kobj(kobject);
  
  	return container_of(kobj, struct xlog, l_kobj);
  }

  STATIC ssize_t
  log_head_lsn_show(

  	struct kobject	*kobject,
  	char		*buf)

  {

  	int cycle;
  	int block;

  	struct xlog *log = to_xlog(kobject);

  
  	spin_lock(&log->l_icloglock);
  	cycle = log->l_curr_cycle;
  	block = log->l_curr_block;
  	spin_unlock(&log->l_icloglock);
  
  	return snprintf(buf, PAGE_SIZE, "%d:%d
  ", cycle, block);
  }
  XFS_SYSFS_ATTR_RO(log_head_lsn);
  
  STATIC ssize_t
  log_tail_lsn_show(

  	struct kobject	*kobject,
  	char		*buf)

  {

  	int cycle;
  	int block;

  	struct xlog *log = to_xlog(kobject);

  
  	xlog_crack_atomic_lsn(&log->l_tail_lsn, &cycle, &block);
  	return snprintf(buf, PAGE_SIZE, "%d:%d
  ", cycle, block);
  }
  XFS_SYSFS_ATTR_RO(log_tail_lsn);
  
  STATIC ssize_t
  reserve_grant_head_show(

  	struct kobject	*kobject,
  	char		*buf)

  {

  	int cycle;
  	int bytes;

  	struct xlog *log = to_xlog(kobject);

  
  	xlog_crack_grant_head(&log->l_reserve_head.grant, &cycle, &bytes);
  	return snprintf(buf, PAGE_SIZE, "%d:%d
  ", cycle, bytes);
  }
  XFS_SYSFS_ATTR_RO(reserve_grant_head);
  
  STATIC ssize_t
  write_grant_head_show(

  	struct kobject	*kobject,
  	char		*buf)

  {

  	int cycle;
  	int bytes;

  	struct xlog *log = to_xlog(kobject);

  
  	xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &bytes);
  	return snprintf(buf, PAGE_SIZE, "%d:%d
  ", cycle, bytes);
  }
  XFS_SYSFS_ATTR_RO(write_grant_head);

  static struct attribute *xfs_log_attrs[] = {

  	ATTR_LIST(log_head_lsn),
  	ATTR_LIST(log_tail_lsn),
  	ATTR_LIST(reserve_grant_head),
  	ATTR_LIST(write_grant_head),

  	NULL,
  };

  struct kobj_type xfs_log_ktype = {
  	.release = xfs_sysfs_release,

  	.sysfs_ops = &xfs_sysfs_ops,

  	.default_attrs = xfs_log_attrs,
  };

  
  /*
   * Metadata IO error configuration
   *
   * The sysfs structure here is:
   *	...xfs/<dev>/error/<class>/<errno>/<error_attrs>
   *
   * where <class> allows us to discriminate between data IO and metadata IO,
   * and any other future type of IO (e.g. special inode or directory error
   * handling) we care to support.
   */

  static inline struct xfs_error_cfg *
  to_error_cfg(struct kobject *kobject)
  {
  	struct xfs_kobj *kobj = to_kobj(kobject);
  	return container_of(kobj, struct xfs_error_cfg, kobj);
  }

  static inline struct xfs_mount *
  err_to_mp(struct kobject *kobject)
  {
  	struct xfs_kobj *kobj = to_kobj(kobject);
  	return container_of(kobj, struct xfs_mount, m_error_kobj);
  }

  static ssize_t
  max_retries_show(
  	struct kobject	*kobject,
  	char		*buf)
  {

  	int		retries;

  	struct xfs_error_cfg *cfg = to_error_cfg(kobject);

  	if (cfg->max_retries == XFS_ERR_RETRY_FOREVER)

  		retries = -1;
  	else
  		retries = cfg->max_retries;
  
  	return snprintf(buf, PAGE_SIZE, "%d
  ", retries);

  }
  
  static ssize_t
  max_retries_store(
  	struct kobject	*kobject,
  	const char	*buf,
  	size_t		count)
  {
  	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
  	int		ret;
  	int		val;
  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;
  
  	if (val < -1)
  		return -EINVAL;

  	if (val == -1)

  		cfg->max_retries = XFS_ERR_RETRY_FOREVER;

  	else
  		cfg->max_retries = val;

  	return count;
  }
  XFS_SYSFS_ATTR_RW(max_retries);
  
  static ssize_t
  retry_timeout_seconds_show(
  	struct kobject	*kobject,
  	char		*buf)
  {

  	int		timeout;

  	struct xfs_error_cfg *cfg = to_error_cfg(kobject);

  	if (cfg->retry_timeout == XFS_ERR_RETRY_FOREVER)
  		timeout = -1;
  	else
  		timeout = jiffies_to_msecs(cfg->retry_timeout) / MSEC_PER_SEC;
  
  	return snprintf(buf, PAGE_SIZE, "%d
  ", timeout);

  }
  
  static ssize_t
  retry_timeout_seconds_store(
  	struct kobject	*kobject,
  	const char	*buf,
  	size_t		count)
  {
  	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
  	int		ret;
  	int		val;
  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;

  	/* 1 day timeout maximum, -1 means infinite */
  	if (val < -1 || val > 86400)

  		return -EINVAL;

  	if (val == -1)
  		cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
  	else {
  		cfg->retry_timeout = msecs_to_jiffies(val * MSEC_PER_SEC);
  		ASSERT(msecs_to_jiffies(val * MSEC_PER_SEC) < LONG_MAX);
  	}

  	return count;
  }
  XFS_SYSFS_ATTR_RW(retry_timeout_seconds);

  static ssize_t
  fail_at_unmount_show(
  	struct kobject	*kobject,
  	char		*buf)
  {
  	struct xfs_mount	*mp = err_to_mp(kobject);
  
  	return snprintf(buf, PAGE_SIZE, "%d
  ", mp->m_fail_unmount);
  }
  
  static ssize_t
  fail_at_unmount_store(
  	struct kobject	*kobject,
  	const char	*buf,
  	size_t		count)
  {
  	struct xfs_mount	*mp = err_to_mp(kobject);
  	int		ret;
  	int		val;
  
  	ret = kstrtoint(buf, 0, &val);
  	if (ret)
  		return ret;
  
  	if (val < 0 || val > 1)
  		return -EINVAL;
  
  	mp->m_fail_unmount = val;
  	return count;
  }
  XFS_SYSFS_ATTR_RW(fail_at_unmount);

  static struct attribute *xfs_error_attrs[] = {
  	ATTR_LIST(max_retries),
  	ATTR_LIST(retry_timeout_seconds),
  	NULL,
  };

  static struct kobj_type xfs_error_cfg_ktype = {

  	.release = xfs_sysfs_release,
  	.sysfs_ops = &xfs_sysfs_ops,
  	.default_attrs = xfs_error_attrs,
  };

  static struct kobj_type xfs_error_ktype = {

  	.release = xfs_sysfs_release,

  	.sysfs_ops = &xfs_sysfs_ops,

  };

  /*
   * Error initialization tables. These need to be ordered in the same
   * order as the enums used to index the array. All class init tables need to
   * define a "default" behaviour as the first entry, all other entries can be
   * empty.
   */
  struct xfs_error_init {
  	char		*name;
  	int		max_retries;

  	int		retry_timeout;	/* in seconds */

  };
  
  static const struct xfs_error_init xfs_error_meta_init[XFS_ERR_ERRNO_MAX] = {
  	{ .name = "default",

  	  .max_retries = XFS_ERR_RETRY_FOREVER,

  	  .retry_timeout = XFS_ERR_RETRY_FOREVER,

  	},

  	{ .name = "EIO",
  	  .max_retries = XFS_ERR_RETRY_FOREVER,

  	  .retry_timeout = XFS_ERR_RETRY_FOREVER,

  	},
  	{ .name = "ENOSPC",
  	  .max_retries = XFS_ERR_RETRY_FOREVER,

  	  .retry_timeout = XFS_ERR_RETRY_FOREVER,

  	},
  	{ .name = "ENODEV",

  	  .max_retries = 0,	/* We can't recover from devices disappearing */
  	  .retry_timeout = 0,

  	},

  };
  
  static int
  xfs_error_sysfs_init_class(
  	struct xfs_mount	*mp,
  	int			class,
  	const char		*parent_name,
  	struct xfs_kobj		*parent_kobj,
  	const struct xfs_error_init init[])
  {
  	struct xfs_error_cfg	*cfg;
  	int			error;
  	int			i;
  
  	ASSERT(class < XFS_ERR_CLASS_MAX);
  
  	error = xfs_sysfs_init(parent_kobj, &xfs_error_ktype,
  				&mp->m_error_kobj, parent_name);
  	if (error)
  		return error;
  
  	for (i = 0; i < XFS_ERR_ERRNO_MAX; i++) {
  		cfg = &mp->m_error_cfg[class][i];
  		error = xfs_sysfs_init(&cfg->kobj, &xfs_error_cfg_ktype,
  					parent_kobj, init[i].name);
  		if (error)
  			goto out_error;
  
  		cfg->max_retries = init[i].max_retries;

  		if (init[i].retry_timeout == XFS_ERR_RETRY_FOREVER)
  			cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
  		else
  			cfg->retry_timeout = msecs_to_jiffies(

  					init[i].retry_timeout * MSEC_PER_SEC);

  	}
  	return 0;
  
  out_error:
  	/* unwind the entries that succeeded */
  	for (i--; i >= 0; i--) {
  		cfg = &mp->m_error_cfg[class][i];
  		xfs_sysfs_del(&cfg->kobj);
  	}
  	xfs_sysfs_del(parent_kobj);
  	return error;
  }

  int
  xfs_error_sysfs_init(
  	struct xfs_mount	*mp)
  {
  	int			error;
  
  	/* .../xfs/<dev>/error/ */
  	error = xfs_sysfs_init(&mp->m_error_kobj, &xfs_error_ktype,
  				&mp->m_kobj, "error");

  	if (error)
  		return error;

  	error = sysfs_create_file(&mp->m_error_kobj.kobject,
  				  ATTR_LIST(fail_at_unmount));
  
  	if (error)
  		goto out_error;

  	/* .../xfs/<dev>/error/metadata/ */

  	error = xfs_error_sysfs_init_class(mp, XFS_ERR_METADATA,
  				"metadata", &mp->m_error_meta_kobj,
  				xfs_error_meta_init);

  	if (error)
  		goto out_error;

  	return 0;

  out_error:
  	xfs_sysfs_del(&mp->m_error_kobj);

  	return error;
  }
  
  void
  xfs_error_sysfs_del(
  	struct xfs_mount	*mp)
  {

  	struct xfs_error_cfg	*cfg;
  	int			i, j;
  
  	for (i = 0; i < XFS_ERR_CLASS_MAX; i++) {
  		for (j = 0; j < XFS_ERR_ERRNO_MAX; j++) {
  			cfg = &mp->m_error_cfg[i][j];
  
  			xfs_sysfs_del(&cfg->kobj);
  		}
  	}
  	xfs_sysfs_del(&mp->m_error_meta_kobj);

  	xfs_sysfs_del(&mp->m_error_kobj);
  }

  
  struct xfs_error_cfg *
  xfs_error_get_cfg(
  	struct xfs_mount	*mp,
  	int			error_class,
  	int			error)
  {
  	struct xfs_error_cfg	*cfg;

  	if (error < 0)
  		error = -error;

  	switch (error) {

  	case EIO:
  		cfg = &mp->m_error_cfg[error_class][XFS_ERR_EIO];
  		break;
  	case ENOSPC:
  		cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENOSPC];
  		break;
  	case ENODEV:
  		cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENODEV];
  		break;

  	default:
  		cfg = &mp->m_error_cfg[error_class][XFS_ERR_DEFAULT];
  		break;
  	}
  
  	return cfg;
  }