source: vendor/current/source3/modules/onefs_cbrl.c@ 590

/*
 * Unix SMB/CIFS implementation.
 * Support for OneFS system interfaces.
 *
 * Copyright (C) Zack Kirsch, 2009
 *
 * 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; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
 */

#include "includes.h"
#include "onefs.h"

#include <ifs/ifs_syscalls.h>
#include <sys/isi_cifs_brl.h>
#include <isi_ecs/isi_ecs_cbrl.h>

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_LOCKING

extern struct blocking_lock_record *blocking_lock_queue;

static uint64_t onefs_get_new_id(void) {
        static uint64_t id = 0;

        id++;

        return id;
}

enum onefs_cbrl_lock_state {ONEFS_CBRL_NONE, ONEFS_CBRL_ASYNC, ONEFS_CBRL_DONE,
        ONEFS_CBRL_ERROR};

struct onefs_cbrl_blr_state {
        uint64_t id;
        enum onefs_cbrl_lock_state state;
};

static char *onefs_cbrl_blr_state_str(const struct blocking_lock_record *blr)
{
        static fstring result;
        struct onefs_cbrl_blr_state *bs;

        SMB_ASSERT(blr);

        bs = (struct onefs_cbrl_blr_state *)blr->blr_private;

        if (bs == NULL) {
                fstrcpy(result, "NULL CBRL BLR state - Posix lock?");
                return result;
        }

        switch (bs->state) {
        case ONEFS_CBRL_NONE:
                fstr_sprintf(result, "CBRL BLR id=%llu: state=NONE", bs->id);
                break;
        case ONEFS_CBRL_ASYNC:
                fstr_sprintf(result, "CBRL BLR id=%llu: state=ASYNC", bs->id);
                break;
        case ONEFS_CBRL_DONE:
                fstr_sprintf(result, "CBRL BLR id=%llu: state=DONE", bs->id);
                break;
        case ONEFS_CBRL_ERROR:
                fstr_sprintf(result, "CBRL BLR id=%llu: state=ERROR", bs->id);
                break;
        default:
                fstr_sprintf(result, "CBRL BLR id=%llu: unknown state %d",
                    bs->id, bs->state);
                break;
        }

        return result;
}

static void onefs_cbrl_enumerate_blq(const char *fn)
{
        struct blocking_lock_record *blr;

        if (DEBUGLVL(10))
                return;

        DEBUG(10, ("CBRL BLR records (%s):\n", fn));

        for (blr = blocking_lock_queue; blr; blr = blr->next)
                DEBUGADD(10, ("%s\n", onefs_cbrl_blr_state_str(blr)));
}

static struct blocking_lock_record *onefs_cbrl_find_blr(uint64_t id)
{
        struct blocking_lock_record *blr;
        struct onefs_cbrl_blr_state *bs;

        onefs_cbrl_enumerate_blq("onefs_cbrl_find_blr");

        for (blr = blocking_lock_queue; blr; blr = blr->next) {
                bs = (struct onefs_cbrl_blr_state *)blr->blr_private;

                /* We don't control all of the BLRs on the BLQ. */
                if (bs == NULL)
                        continue;

                if (bs->id == id) {
                        DEBUG(10, ("found %s\n",
                            onefs_cbrl_blr_state_str(blr)));
                        break;
                }
        }

        if (blr == NULL) {
                DEBUG(5, ("Could not find CBRL BLR for id %llu\n", id));
                return NULL;
        }

        return blr;
}

static void onefs_cbrl_async_success(uint64_t id)
{
        struct blocking_lock_record *blr;
        struct onefs_cbrl_blr_state *bs;
        uint16 num_locks;

        DEBUG(10, ("CBRL async success!\n"));

        /* Find BLR with id. Its okay not to find one (race with cancel) */
        blr = onefs_cbrl_find_blr(id);
        if (blr == NULL)
                return;

        bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
        SMB_ASSERT(bs);
        SMB_ASSERT(bs->state == ONEFS_CBRL_ASYNC);

        blr->lock_num++;

        num_locks = SVAL(blr->req->vwv+7, 0);

        if (blr->lock_num == num_locks)
                bs->state = ONEFS_CBRL_DONE;
        else
                bs->state = ONEFS_CBRL_NONE;

        /* Self contend our own level 2 oplock. The kernel handles
         * contention of other opener's level 2 oplocks. */
        contend_level2_oplocks_begin(blr->fsp,
            LEVEL2_CONTEND_WINDOWS_BRL);

        /* Process the queue, to try the next lock or finish up. */
        process_blocking_lock_queue();
}

static void onefs_cbrl_async_failure(uint64_t id)
{
        struct blocking_lock_record *blr;
        struct onefs_cbrl_blr_state *bs;

        DEBUG(10, ("CBRL async failure!\n"));

        /* Find BLR with id. Its okay not to find one (race with cancel) */
        blr = onefs_cbrl_find_blr(id);
        if (blr == NULL)
                return;

        bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
        SMB_ASSERT(bs);

        SMB_ASSERT(bs->state == ONEFS_CBRL_ASYNC);
        bs->state = ONEFS_CBRL_ERROR;

        /* Process the queue. It will end up trying to retake the same lock,
         * see the error in onefs_cbrl_lock_windows() and fail. */
        process_blocking_lock_queue();
}

static struct cbrl_event_ops cbrl_ops =
    {.cbrl_async_success = onefs_cbrl_async_success,
     .cbrl_async_failure = onefs_cbrl_async_failure};