/*
   Copyright (c) 2006-2012 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#include <pthread.h>

#include <glusterfs/glusterfs.h>
#include <glusterfs/compat.h>
#include <glusterfs/xlator.h>
#include <glusterfs/logging.h>
#include <glusterfs/common-utils.h>

#include "locks.h"
#include "common.h"
#include <glusterfs/statedump.h>
#include "clear.h"

const char *clrlk_type_names[CLRLK_TYPE_MAX] = {
    [CLRLK_INODE] = "inode",
    [CLRLK_ENTRY] = "entry",
    [CLRLK_POSIX] = "posix",
};

int
clrlk_get_kind(char *kind)
{
    char *clrlk_kinds[CLRLK_KIND_MAX] = {"dummy", "blocked", "granted", "all"};
    int ret_kind = CLRLK_KIND_MAX;
    int i = 0;

    for (i = CLRLK_BLOCKED; i < CLRLK_KIND_MAX; i++) {
        if (!strcmp(clrlk_kinds[i], kind)) {
            ret_kind = i;
            break;
        }
    }

    return ret_kind;
}

int
clrlk_get_type(char *type)
{
    char *clrlk_types[CLRLK_TYPE_MAX] = {"inode", "entry", "posix"};
    int ret_type = CLRLK_TYPE_MAX;
    int i = 0;

    for (i = CLRLK_INODE; i < CLRLK_TYPE_MAX; i++) {
        if (!strcmp(clrlk_types[i], type)) {
            ret_type = i;
            break;
        }
    }

    return ret_type;
}

int
clrlk_get_lock_range(char *range_str, struct gf_flock *ulock,
                     gf_boolean_t *chk_range)
{
    int ret = -1;

    if (!chk_range)
        goto out;

    if (!range_str) {
        ret = 0;
        *chk_range = _gf_false;
        goto out;
    }

    if (sscanf(range_str,
               "%hd,%" PRId64 "-"
               "%" PRId64,
               &ulock->l_whence, &ulock->l_start, &ulock->l_len) != 3) {
        goto out;
    }

    ret = 0;
    *chk_range = _gf_true;
out:
    return ret;
}

int
clrlk_parse_args(const char *cmd, clrlk_args *args)
{
    char *opts = NULL;
    char *cur = NULL;
    char *tok = NULL;
    char *sptr = NULL;
    char *free_ptr = NULL;
    char kw[KW_MAX] = {
        [KW_TYPE] = 't',
        [KW_KIND] = 'k',
    };
    int ret = -1;
    int i = 0;

    GF_ASSERT(cmd);
    free_ptr = opts = GF_CALLOC(1, strlen(cmd), gf_common_mt_char);
    if (!opts)
        goto out;

    if (sscanf(cmd, GF_XATTR_CLRLK_CMD ".%s", opts) < 1) {
        ret = -1;
        goto out;
    }

    /*clr_lk_prefix.ttype.kkind.args, args - type specific*/
    cur = opts;
    for (i = 0; i < KW_MAX && (tok = strtok_r(cur, ".", &sptr));
         cur = NULL, i++) {
        if (tok[0] != kw[i]) {
            ret = -1;
            goto out;
        }
        if (i == KW_TYPE)
            args->type = clrlk_get_type(tok + 1);
        if (i == KW_KIND)
            args->kind = clrlk_get_kind(tok + 1);
    }

    if ((args->type == CLRLK_TYPE_MAX) || (args->kind == CLRLK_KIND_MAX))
        goto out;

    /*optional args, neither range nor basename can 'legally' contain
     * "/" in them*/
    tok = strtok_r(NULL, "/", &sptr);
    if (tok)
        args->opts = gf_strdup(tok);

    ret = 0;
out:
    GF_FREE(free_ptr);
    return ret;
}

int
clrlk_clear_posixlk(xlator_t *this, pl_inode_t *pl_inode, clrlk_args *args,
                    int *blkd, int *granted, int *op_errno)
{
    posix_lock_t *plock = NULL;
    posix_lock_t *tmp = NULL;
    struct gf_flock ulock = {
        0,
    };
    int ret = -1;
    int bcount = 0;
    int gcount = 0;
    gf_boolean_t chk_range = _gf_false;

    if (clrlk_get_lock_range(args->opts, &ulock, &chk_range)) {
        *op_errno = EINVAL;
        goto out;
    }

    pthread_mutex_lock(&pl_inode->mutex);
    {
        list_for_each_entry_safe(plock, tmp, &pl_inode->ext_list, list)
        {
            if ((plock->blocked && !(args->kind & CLRLK_BLOCKED)) ||
                (!plock->blocked && !(args->kind & CLRLK_GRANTED)))
                continue;

            if (chk_range && (plock->user_flock.l_whence != ulock.l_whence ||
                              plock->user_flock.l_start != ulock.l_start ||
                              plock->user_flock.l_len != ulock.l_len))
                continue;

            list_del_init(&plock->list);
            if (plock->blocked) {
                bcount++;
                pl_trace_out(this, plock->frame, NULL, NULL, F_SETLKW,
                             &plock->user_flock, -1, EINTR, NULL);

                STACK_UNWIND_STRICT(lk, plock->frame, -1, EINTR,
                                    &plock->user_flock, NULL);

            } else {
                gcount++;
            }
            __destroy_lock(plock);
        }
    }
    pthread_mutex_unlock(&pl_inode->mutex);
    grant_blocked_locks(this, pl_inode);
    ret = 0;
out:
    *blkd = bcount;
    *granted = gcount;
    return ret;
}

/* Returns 0 on success and -1 on failure */
int
clrlk_clear_inodelk(xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
                    clrlk_args *args, int *blkd, int *granted, int *op_errno)
{
    posix_locks_private_t *priv;
    pl_inode_lock_t *ilock = NULL;
    pl_inode_lock_t *tmp = NULL;
    struct gf_flock ulock = {
        0,
    };
    int ret = -1;
    int bcount = 0;
    int gcount = 0;
    gf_boolean_t chk_range = _gf_false;
    struct list_head *pcontend = NULL;
    struct list_head released;
    struct list_head contend;
    struct timespec now = {};

    INIT_LIST_HEAD(&released);

    priv = this->private;
    if (priv->notify_contention) {
        pcontend = &contend;
        INIT_LIST_HEAD(pcontend);
        timespec_now(&now);
    }

    if (clrlk_get_lock_range(args->opts, &ulock, &chk_range)) {
        *op_errno = EINVAL;
        goto out;
    }

    if (args->kind & CLRLK_BLOCKED)
        goto blkd;

    if (args->kind & CLRLK_GRANTED)
        goto granted;

blkd:
    pthread_mutex_lock(&pl_inode->mutex);
    {
        list_for_each_entry_safe(ilock, tmp, &dom->blocked_inodelks,
                                 blocked_locks)
        {
            if (chk_range && (ilock->user_flock.l_whence != ulock.l_whence ||
                              ilock->user_flock.l_start != ulock.l_start ||
                              ilock->user_flock.l_len != ulock.l_len))
                continue;

            bcount++;
            list_del_init(&ilock->client_list);
            list_del_init(&ilock->blocked_locks);
            list_add(&ilock->blocked_locks, &released);
        }
    }
    pthread_mutex_unlock(&pl_inode->mutex);

    if (!list_empty(&released)) {
        list_for_each_entry_safe(ilock, tmp, &released, blocked_locks)
        {
            list_del_init(&ilock->blocked_locks);
            pl_trace_out(this, ilock->frame, NULL, NULL, F_SETLKW,
                         &ilock->user_flock, -1, EAGAIN, ilock->volume);
            STACK_UNWIND_STRICT(inodelk, ilock->frame, -1, EAGAIN, NULL);
            // No need to take lock as the locks are only in one list
            __pl_inodelk_unref(ilock);
        }
    }

    if (!(args->kind & CLRLK_GRANTED)) {
        ret = 0;
        goto out;
    }

granted:
    pthread_mutex_lock(&pl_inode->mutex);
    {
        list_for_each_entry_safe(ilock, tmp, &dom->inodelk_list, list)
        {
            if (chk_range && (ilock->user_flock.l_whence != ulock.l_whence ||
                              ilock->user_flock.l_start != ulock.l_start ||
                              ilock->user_flock.l_len != ulock.l_len))
                continue;

            gcount++;
            list_del_init(&ilock->client_list);
            list_del_init(&ilock->list);
            list_add(&ilock->list, &released);
        }
    }
    pthread_mutex_unlock(&pl_inode->mutex);

    list_for_each_entry_safe(ilock, tmp, &released, list)
    {
        list_del_init(&ilock->list);
        // No need to take lock as the locks are only in one list
        __pl_inodelk_unref(ilock);
    }

    ret = 0;
out:
    grant_blocked_inode_locks(this, pl_inode, dom, &now, pcontend);
    if (pcontend != NULL) {
        inodelk_contention_notify(this, pcontend);
    }
    *blkd = bcount;
    *granted = gcount;
    return ret;
}

/* Returns 0 on success and -1 on failure */
int
clrlk_clear_entrylk(xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
                    clrlk_args *args, int *blkd, int *granted, int *op_errno)
{
    posix_locks_private_t *priv;
    pl_entry_lock_t *elock = NULL;
    pl_entry_lock_t *tmp = NULL;
    int bcount = 0;
    int gcount = 0;
    int ret = -1;
    struct list_head *pcontend = NULL;
    struct list_head removed;
    struct list_head released;
    struct list_head contend;
    struct timespec now;

    INIT_LIST_HEAD(&released);

    priv = this->private;
    if (priv->notify_contention) {
        pcontend = &contend;
        INIT_LIST_HEAD(pcontend);
        timespec_now(&now);
    }

    if (args->kind & CLRLK_BLOCKED)
        goto blkd;

    if (args->kind & CLRLK_GRANTED)
        goto granted;

blkd:
    pthread_mutex_lock(&pl_inode->mutex);
    {
        list_for_each_entry_safe(elock, tmp, &dom->blocked_entrylks,
                                 blocked_locks)
        {
            if (args->opts) {
                if (!elock->basename || strcmp(elock->basename, args->opts))
                    continue;
            }

            bcount++;

            list_del_init(&elock->client_list);
            list_del_init(&elock->blocked_locks);
            list_add_tail(&elock->blocked_locks, &released);
        }
    }
    pthread_mutex_unlock(&pl_inode->mutex);

    if (!list_empty(&released)) {
        list_for_each_entry_safe(elock, tmp, &released, blocked_locks)
        {
            list_del_init(&elock->blocked_locks);
            entrylk_trace_out(this, elock->frame, elock->volume, NULL, NULL,
                              elock->basename, ENTRYLK_LOCK, elock->type, -1,
                              EAGAIN);
            STACK_UNWIND_STRICT(entrylk, elock->frame, -1, EAGAIN, NULL);

            __pl_entrylk_unref(elock);
        }
    }

    if (!(args->kind & CLRLK_GRANTED)) {
        ret = 0;
        goto out;
    }

granted:
    INIT_LIST_HEAD(&removed);
    pthread_mutex_lock(&pl_inode->mutex);
    {
        list_for_each_entry_safe(elock, tmp, &dom->entrylk_list, domain_list)
        {
            if (args->opts) {
                if (!elock->basename || strcmp(elock->basename, args->opts))
                    continue;
            }

            gcount++;
            list_del_init(&elock->client_list);
            list_del_init(&elock->domain_list);
            list_add_tail(&elock->domain_list, &removed);

            __pl_entrylk_unref(elock);
        }
    }
    pthread_mutex_unlock(&pl_inode->mutex);

    grant_blocked_entry_locks(this, pl_inode, dom, &now, pcontend);
    if (pcontend != NULL) {
        entrylk_contention_notify(this, pcontend);
    }

    ret = 0;
out:
    *blkd = bcount;
    *granted = gcount;
    return ret;
}

int
clrlk_clear_lks_in_all_domains(xlator_t *this, pl_inode_t *pl_inode,
                               clrlk_args *args, int *blkd, int *granted,
                               int *op_errno)
{
    pl_dom_list_t *dom = NULL;
    int ret = -1;
    int tmp_bcount = 0;
    int tmp_gcount = 0;

    if (list_empty(&pl_inode->dom_list)) {
        ret = 0;
        goto out;
    }

    list_for_each_entry(dom, &pl_inode->dom_list, inode_list)
    {
        tmp_bcount = tmp_gcount = 0;

        switch (args->type) {
            case CLRLK_INODE:
                ret = clrlk_clear_inodelk(this, pl_inode, dom, args,
                                          &tmp_bcount, &tmp_gcount, op_errno);
                if (ret)
                    goto out;
                break;
            case CLRLK_ENTRY:
                ret = clrlk_clear_entrylk(this, pl_inode, dom, args,
                                          &tmp_bcount, &tmp_gcount, op_errno);
                if (ret)
                    goto out;
                break;
        }

        *blkd += tmp_bcount;
        *granted += tmp_gcount;
    }

    ret = 0;
out:
    return ret;
}