/*
   * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.

   * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.

   *
   * This copyrighted material is made available to anyone wishing to use,
   * modify, copy, or redistribute it subject to the terms and conditions

   * of the GNU General Public License version 2.

   */
  
  #include <linux/sched.h>

  #include <linux/spinlock.h>
  #include <linux/completion.h>
  #include <linux/buffer_head.h>
  #include <linux/module.h>
  #include <linux/kobject.h>

  #include <asm/uaccess.h>

  #include <linux/gfs2_ondisk.h>

  #include <linux/genhd.h>

  
  #include "gfs2.h"

  #include "incore.h"

  #include "sys.h"
  #include "super.h"
  #include "glock.h"
  #include "quota.h"

  #include "util.h"

  #include "glops.h"

  #include "recovery.h"

  struct gfs2_attr {
  	struct attribute attr;
  	ssize_t (*show)(struct gfs2_sbd *, char *);
  	ssize_t (*store)(struct gfs2_sbd *, const char *, size_t);
  };
  
  static ssize_t gfs2_attr_show(struct kobject *kobj, struct attribute *attr,
  			      char *buf)
  {
  	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
  	struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
  	return a->show ? a->show(sdp, buf) : 0;
  }
  
  static ssize_t gfs2_attr_store(struct kobject *kobj, struct attribute *attr,
  			       const char *buf, size_t len)
  {
  	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
  	struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
  	return a->store ? a->store(sdp, buf, len) : len;
  }

  static const struct sysfs_ops gfs2_attr_ops = {

  	.show  = gfs2_attr_show,
  	.store = gfs2_attr_store,
  };
  
  
  static struct kset *gfs2_kset;

  static ssize_t id_show(struct gfs2_sbd *sdp, char *buf)
  {

  	return snprintf(buf, PAGE_SIZE, "%u:%u
  ",
  			MAJOR(sdp->sd_vfs->s_dev), MINOR(sdp->sd_vfs->s_dev));

  }
  
  static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
  {

  	return snprintf(buf, PAGE_SIZE, "%s
  ", sdp->sd_fsname);

  }

  static int gfs2_uuid_valid(const u8 *uuid)
  {
  	int i;
  
  	for (i = 0; i < 16; i++) {
  		if (uuid[i])
  			return 1;
  	}
  	return 0;
  }
  
  static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
  {

  	struct super_block *s = sdp->sd_vfs;
  	const u8 *uuid = s->s_uuid;

  	buf[0] = '\0';
  	if (!gfs2_uuid_valid(uuid))
  		return 0;

  	return snprintf(buf, PAGE_SIZE, "%pUB
  ", uuid);

  }

  static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
  {
  	unsigned int count;

  	mutex_lock(&sdp->sd_freeze_lock);

  	count = sdp->sd_freeze_count;

  	mutex_unlock(&sdp->sd_freeze_lock);

  	return snprintf(buf, PAGE_SIZE, "%u
  ", count);

  }
  
  static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {
  	ssize_t ret = len;
  	int error = 0;
  	int n = simple_strtol(buf, NULL, 0);
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	switch (n) {
  	case 0:
  		gfs2_unfreeze_fs(sdp);
  		break;
  	case 1:
  		error = gfs2_freeze_fs(sdp);
  		break;
  	default:
  		ret = -EINVAL;
  	}
  
  	if (error)
  		fs_warn(sdp, "freeze %d error %d", n, error);
  
  	return ret;
  }
  
  static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)
  {
  	unsigned int b = test_bit(SDF_SHUTDOWN, &sdp->sd_flags);

  	return snprintf(buf, PAGE_SIZE, "%u
  ", b);

  }
  
  static ssize_t withdraw_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	if (simple_strtol(buf, NULL, 0) != 1)
  		return -EINVAL;
  
  	gfs2_lm_withdraw(sdp,
  		"GFS2: fsid=%s: withdrawing from cluster at user's request
  ",
  		sdp->sd_fsname);
  	return len;
  }
  
  static ssize_t statfs_sync_store(struct gfs2_sbd *sdp, const char *buf,
  				 size_t len)
  {
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	if (simple_strtol(buf, NULL, 0) != 1)
  		return -EINVAL;

  	gfs2_statfs_sync(sdp->sd_vfs, 0);

  	return len;
  }

  static ssize_t quota_sync_store(struct gfs2_sbd *sdp, const char *buf,
  				size_t len)
  {
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	if (simple_strtol(buf, NULL, 0) != 1)
  		return -EINVAL;

  	gfs2_quota_sync(sdp->sd_vfs, 0, 1);

  	return len;
  }
  
  static ssize_t quota_refresh_user_store(struct gfs2_sbd *sdp, const char *buf,
  					size_t len)
  {

  	int error;

  	u32 id;

  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	id = simple_strtoul(buf, NULL, 0);

  	error = gfs2_quota_refresh(sdp, 1, id);
  	return error ? error : len;

  }
  
  static ssize_t quota_refresh_group_store(struct gfs2_sbd *sdp, const char *buf,
  					 size_t len)
  {

  	int error;

  	u32 id;

  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	id = simple_strtoul(buf, NULL, 0);

  	error = gfs2_quota_refresh(sdp, 0, id);
  	return error ? error : len;

  }

  static ssize_t demote_rq_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {
  	struct gfs2_glock *gl;
  	const struct gfs2_glock_operations *glops;
  	unsigned int glmode;
  	unsigned int gltype;
  	unsigned long long glnum;
  	char mode[16];
  	int rv;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	rv = sscanf(buf, "%u:%llu %15s", &gltype, &glnum,
  		    mode);
  	if (rv != 3)
  		return -EINVAL;
  
  	if (strcmp(mode, "EX") == 0)
  		glmode = LM_ST_UNLOCKED;
  	else if ((strcmp(mode, "CW") == 0) || (strcmp(mode, "DF") == 0))
  		glmode = LM_ST_DEFERRED;
  	else if ((strcmp(mode, "PR") == 0) || (strcmp(mode, "SH") == 0))
  		glmode = LM_ST_SHARED;
  	else
  		return -EINVAL;
  
  	if (gltype > LM_TYPE_JOURNAL)
  		return -EINVAL;

  	if (gltype == LM_TYPE_NONDISK && glnum == GFS2_TRANS_LOCK)
  		glops = &gfs2_trans_glops;
  	else
  		glops = gfs2_glops_list[gltype];

  	if (glops == NULL)
  		return -EINVAL;

  	if (!test_and_set_bit(SDF_DEMOTE, &sdp->sd_flags))

  		fs_info(sdp, "demote interface used
  ");

  	rv = gfs2_glock_get(sdp, glnum, glops, 0, &gl);
  	if (rv)
  		return rv;
  	gfs2_glock_cb(gl, glmode);
  	gfs2_glock_put(gl);
  	return len;
  }

  
  #define GFS2_ATTR(name, mode, show, store) \
  static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)
  
  GFS2_ATTR(id,                  0444, id_show,       NULL);
  GFS2_ATTR(fsname,              0444, fsname_show,   NULL);

  GFS2_ATTR(uuid,                0444, uuid_show,     NULL);

  GFS2_ATTR(freeze,              0644, freeze_show,   freeze_store);

  GFS2_ATTR(withdraw,            0644, withdraw_show, withdraw_store);
  GFS2_ATTR(statfs_sync,         0200, NULL,          statfs_sync_store);
  GFS2_ATTR(quota_sync,          0200, NULL,          quota_sync_store);
  GFS2_ATTR(quota_refresh_user,  0200, NULL,          quota_refresh_user_store);
  GFS2_ATTR(quota_refresh_group, 0200, NULL,          quota_refresh_group_store);

  GFS2_ATTR(demote_rq,           0200, NULL,	    demote_rq_store);

  
  static struct attribute *gfs2_attrs[] = {
  	&gfs2_attr_id.attr,
  	&gfs2_attr_fsname.attr,

  	&gfs2_attr_uuid.attr,

  	&gfs2_attr_freeze.attr,

  	&gfs2_attr_withdraw.attr,
  	&gfs2_attr_statfs_sync.attr,
  	&gfs2_attr_quota_sync.attr,
  	&gfs2_attr_quota_refresh_user.attr,
  	&gfs2_attr_quota_refresh_group.attr,

  	&gfs2_attr_demote_rq.attr,

  	NULL,
  };

  static struct kobj_type gfs2_ktype = {
  	.default_attrs = gfs2_attrs,
  	.sysfs_ops     = &gfs2_attr_ops,
  };

  
  /*
   * lock_module. Originally from lock_dlm
   */
  
  static ssize_t proto_name_show(struct gfs2_sbd *sdp, char *buf)
  {
  	const struct lm_lockops *ops = sdp->sd_lockstruct.ls_ops;
  	return sprintf(buf, "%s
  ", ops->lm_proto_name);
  }
  
  static ssize_t block_show(struct gfs2_sbd *sdp, char *buf)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	ssize_t ret;
  	int val = 0;
  
  	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))
  		val = 1;
  	ret = sprintf(buf, "%d
  ", val);
  	return ret;
  }
  
  static ssize_t block_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	ssize_t ret = len;
  	int val;
  
  	val = simple_strtol(buf, NULL, 0);
  
  	if (val == 1)
  		set_bit(DFL_BLOCK_LOCKS, &ls->ls_flags);
  	else if (val == 0) {
  		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_flags);
  		smp_mb__after_clear_bit();
  		gfs2_glock_thaw(sdp);
  	} else {
  		ret = -EINVAL;
  	}
  	return ret;
  }

  static ssize_t lkfirst_show(struct gfs2_sbd *sdp, char *buf)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	return sprintf(buf, "%d
  ", ls->ls_first);
  }

  static ssize_t lkfirst_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {
  	unsigned first;
  	int rv;
  
  	rv = sscanf(buf, "%u", &first);
  	if (rv != 1 || first > 1)
  		return -EINVAL;

  	rv = wait_for_completion_killable(&sdp->sd_locking_init);
  	if (rv)
  		return rv;

  	spin_lock(&sdp->sd_jindex_spin);
  	rv = -EBUSY;
  	if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
  		goto out;
  	rv = -EINVAL;
  	if (sdp->sd_args.ar_spectator)
  		goto out;
  	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
  		goto out;
          sdp->sd_lockstruct.ls_first = first;
          rv = 0;
  out:
          spin_unlock(&sdp->sd_jindex_spin);
          return rv ? rv : len;
  }

  static ssize_t first_done_show(struct gfs2_sbd *sdp, char *buf)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	return sprintf(buf, "%d
  ", ls->ls_first_done);
  }

  static ssize_t recover_store(struct gfs2_sbd *sdp, const char *buf, size_t len)

  {

  	unsigned jid;

  	struct gfs2_jdesc *jd;

  	int rv;
  
  	rv = sscanf(buf, "%u", &jid);
  	if (rv != 1)
  		return -EINVAL;

  	rv = -ESHUTDOWN;

  	spin_lock(&sdp->sd_jindex_spin);

  	if (test_bit(SDF_NORECOVERY, &sdp->sd_flags))
  		goto out;
  	rv = -EBUSY;
  	if (sdp->sd_jdesc->jd_jid == jid)
  		goto out;
  	rv = -ENOENT;

  	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
  		if (jd->jd_jid != jid)
  			continue;

  		rv = gfs2_recover_journal(jd, false);

  		break;
  	}

  out:

  	spin_unlock(&sdp->sd_jindex_spin);

  	return rv ? rv : len;

  }
  
  static ssize_t recover_done_show(struct gfs2_sbd *sdp, char *buf)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	return sprintf(buf, "%d
  ", ls->ls_recover_jid_done);
  }
  
  static ssize_t recover_status_show(struct gfs2_sbd *sdp, char *buf)
  {
  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
  	return sprintf(buf, "%d
  ", ls->ls_recover_jid_status);
  }

  static ssize_t jid_show(struct gfs2_sbd *sdp, char *buf)
  {

  	return sprintf(buf, "%d
  ", sdp->sd_lockstruct.ls_jid);

  }

  static ssize_t jid_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
  {

          int jid;

  	int rv;

  	rv = sscanf(buf, "%d", &jid);

  	if (rv != 1)
  		return -EINVAL;

  	rv = wait_for_completion_killable(&sdp->sd_locking_init);
  	if (rv)
  		return rv;

  	spin_lock(&sdp->sd_jindex_spin);
  	rv = -EINVAL;

  	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
  		goto out;
  	rv = -EBUSY;

  	if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)

  		goto out;

  	rv = 0;
  	if (sdp->sd_args.ar_spectator && jid > 0)
  		rv = jid = -EINVAL;

  	sdp->sd_lockstruct.ls_jid = jid;

  	clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);

  	smp_mb__after_clear_bit();
  	wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);

  out:
  	spin_unlock(&sdp->sd_jindex_spin);
  	return rv ? rv : len;
  }

  #define GDLM_ATTR(_name,_mode,_show,_store) \

  static struct gfs2_attr gdlm_attr_##_name = __ATTR(_name,_mode,_show,_store)

  GDLM_ATTR(proto_name,		0444, proto_name_show,		NULL);
  GDLM_ATTR(block,		0644, block_show,		block_store);
  GDLM_ATTR(withdraw,		0644, withdraw_show,		withdraw_store);

  GDLM_ATTR(jid,			0644, jid_show,			jid_store);
  GDLM_ATTR(first,		0644, lkfirst_show,		lkfirst_store);

  GDLM_ATTR(first_done,		0444, first_done_show,		NULL);
  GDLM_ATTR(recover,		0600, NULL,			recover_store);
  GDLM_ATTR(recover_done,		0444, recover_done_show,	NULL);
  GDLM_ATTR(recover_status,	0444, recover_status_show,	NULL);

  
  static struct attribute *lock_module_attrs[] = {
  	&gdlm_attr_proto_name.attr,
  	&gdlm_attr_block.attr,
  	&gdlm_attr_withdraw.attr,

  	&gdlm_attr_jid.attr,

  	&gdlm_attr_first.attr,
  	&gdlm_attr_first_done.attr,
  	&gdlm_attr_recover.attr,
  	&gdlm_attr_recover_done.attr,
  	&gdlm_attr_recover_status.attr,

  	NULL,

  };

  /*

   * get and set struct gfs2_tune fields
   */
  
  static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
  {

  	return snprintf(buf, PAGE_SIZE, "%u %u
  ",
  			sdp->sd_tune.gt_quota_scale_num,
  			sdp->sd_tune.gt_quota_scale_den);

  }
  
  static ssize_t quota_scale_store(struct gfs2_sbd *sdp, const char *buf,
  				 size_t len)
  {
  	struct gfs2_tune *gt = &sdp->sd_tune;
  	unsigned int x, y;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	if (sscanf(buf, "%u %u", &x, &y) != 2 || !y)
  		return -EINVAL;
  
  	spin_lock(&gt->gt_spin);
  	gt->gt_quota_scale_num = x;
  	gt->gt_quota_scale_den = y;
  	spin_unlock(&gt->gt_spin);
  	return len;
  }
  
  static ssize_t tune_set(struct gfs2_sbd *sdp, unsigned int *field,
  			int check_zero, const char *buf, size_t len)
  {
  	struct gfs2_tune *gt = &sdp->sd_tune;
  	unsigned int x;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EACCES;
  
  	x = simple_strtoul(buf, NULL, 0);
  
  	if (check_zero && !x)
  		return -EINVAL;
  
  	spin_lock(&gt->gt_spin);
  	*field = x;
  	spin_unlock(&gt->gt_spin);
  	return len;
  }

  #define TUNE_ATTR_3(name, show, store)                                        \

  static struct gfs2_attr tune_attr_##name = __ATTR(name, 0644, show, store)

  
  #define TUNE_ATTR_2(name, store)                                              \
  static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf)                   \
  {                                                                             \

  	return snprintf(buf, PAGE_SIZE, "%u
  ", sdp->sd_tune.gt_##name);      \

  }                                                                             \
  TUNE_ATTR_3(name, name##_show, store)
  
  #define TUNE_ATTR(name, check_zero)                                           \
  static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
  {                                                                             \
  	return tune_set(sdp, &sdp->sd_tune.gt_##name, check_zero, buf, len);  \
  }                                                                             \
  TUNE_ATTR_2(name, name##_store)

  TUNE_ATTR(quota_warn_period, 0);
  TUNE_ATTR(quota_quantum, 0);

  TUNE_ATTR(max_readahead, 0);
  TUNE_ATTR(complain_secs, 0);

  TUNE_ATTR(statfs_slow, 0);
  TUNE_ATTR(new_files_jdata, 0);

  TUNE_ATTR(quota_simul_sync, 1);

  TUNE_ATTR(statfs_quantum, 1);

  TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);
  
  static struct attribute *tune_attrs[] = {

  	&tune_attr_quota_warn_period.attr,
  	&tune_attr_quota_quantum.attr,

  	&tune_attr_max_readahead.attr,
  	&tune_attr_complain_secs.attr,

  	&tune_attr_statfs_slow.attr,
  	&tune_attr_quota_simul_sync.attr,

  	&tune_attr_statfs_quantum.attr,

  	&tune_attr_quota_scale.attr,
  	&tune_attr_new_files_jdata.attr,

  	NULL,

  };

  static struct attribute_group tune_group = {
  	.name = "tune",

  	.attrs = tune_attrs,

  };

  static struct attribute_group lock_module_group = {
  	.name = "lock_module",
  	.attrs = lock_module_attrs,
  };

  int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
  {

  	struct super_block *sb = sdp->sd_vfs;

  	int error;

  	char ro[20];
  	char spectator[20];
  	char *envp[] = { ro, spectator, NULL };
  
  	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
  	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);

  	sdp->sd_kobj.kset = gfs2_kset;

  	error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL,
  				     "%s", sdp->sd_table_name);

  	if (error)
  		goto fail;

  	error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
  	if (error)

  		goto fail_reg;

  	error = sysfs_create_group(&sdp->sd_kobj, &lock_module_group);
  	if (error)
  		goto fail_tune;

  	error = sysfs_create_link(&sdp->sd_kobj,
  				  &disk_to_dev(sb->s_bdev->bd_disk)->kobj,
  				  "device");
  	if (error)
  		goto fail_lock_module;

  	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ADD, envp);

  	return 0;

  fail_lock_module:
  	sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);

  fail_tune:
  	sysfs_remove_group(&sdp->sd_kobj, &tune_group);

  fail_reg:

  	kobject_put(&sdp->sd_kobj);

  fail:

  	fs_err(sdp, "error %d adding sysfs files", error);

  	return error;
  }
  
  void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
  {

  	sysfs_remove_link(&sdp->sd_kobj, "device");

  	sysfs_remove_group(&sdp->sd_kobj, &tune_group);

  	sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);

  	kobject_put(&sdp->sd_kobj);

  }

  static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
  		       struct kobj_uevent_env *env)
  {
  	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);

  	struct super_block *s = sdp->sd_vfs;
  	const u8 *uuid = s->s_uuid;

  	add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
  	add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);

  	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))

  		add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);

  	if (gfs2_uuid_valid(uuid))
  		add_uevent_var(env, "UUID=%pUB", uuid);

  	return 0;
  }

  static const struct kset_uevent_ops gfs2_uevent_ops = {

  	.uevent = gfs2_uevent,
  };

  int gfs2_sys_init(void)
  {

  	gfs2_kset = kset_create_and_add("gfs2", &gfs2_uevent_ops, fs_kobj);

  	if (!gfs2_kset)
  		return -ENOMEM;
  	return 0;

  }
  
  void gfs2_sys_uninit(void)
  {

  	kset_unregister(gfs2_kset);

  }