sys-small-io.sm

/* 
 * (C) 2003 Clemson University and The University of Chicago 
 *
 * See COPYING in top-level directory.
 */

/** \file
 *  \ingroup sysint
 *
 *  PVFS2 system interface routines for reading and writing small files.
 */

#include <string.h>
#include <assert.h>

#include "client-state-machine.h"
#include "pvfs2-debug.h"
#include "job.h"
#include "gossip.h"
#include "str-utils.h"
#include "pint-cached-config.h"
#include "PINT-reqproto-encode.h"
#include "pint-util.h"
#include "pvfs2-internal.h"

/* The small-io state machine should only be invoked/jumped-to from the
 * sys-io state machine.  We make this assumption and expect io parameters
 * to be initialized already.
 */

static int small_io_completion_fn(void * user_args,
                                  struct PVFS_server_resp * resp_p,
                                  int index);

enum {
  MIRROR_RETRY = 132
};

%%

nested machine pvfs2_client_small_io_sm
{
    state setup_msgpairs 
    {
        run small_io_setup_msgpairs;
        success => xfer_msgpairs;
        default => return;
    }

    state xfer_msgpairs
    {
        jump pvfs2_msgpairarray_sm;
        default => check_for_retries;
    }

    state check_for_retries
    {
        run small_io_check_for_retries;
        MIRROR_RETRY => xfer_msgpairs;
        default => cleanup;  /*no mirroring, done, or out of retries*/ 
    }

    state cleanup 
    {
        run small_io_cleanup;
        default => return;
    }
}

%%

/**
 * Small I/O is done in cases where the size of data transferred between
 * client and server is smaller than the maximum unexpected message size
 * accepted by the BMI transport interface in use.  In this case, we don't
 * need to perform initial rendezvous setup messages before sending the
 * actual data (the 'flow'), instead we just pack the data in the unexpected
 * message.  The sys-io state machine checks for possible 'small i/o' cases
 * and routes to the small i/o state actions in case.
 */
static PINT_sm_action small_io_setup_msgpairs(
    struct PINT_smcb *smcb, job_status_s *js_p)
{
    struct PINT_client_sm *sm_p = PINT_sm_frame(smcb, PINT_FRAME_CURRENT);
    PVFS_object_attr *attr = NULL;
    int i = 0;
    int ret;
    PVFS_handle datafile_handle;
    int regions = 0;
    PINT_sm_msgpair_state *msg_p;
    uint32_t server_nr;

    js_p->error_code = 0;

    attr = &sm_p->getattr.attr;
    assert(attr);

    /* initialize msgarray. one msgpair for each handle with data. */
    ret = PINT_msgpairarray_init(&sm_p->msgarray_op, sm_p->u.io.datafile_count);
    if(ret < 0)
    {
        js_p->error_code = ret;
        return SM_ACTION_COMPLETE;
    }

    /*initialize small_io_ctx array.  one context for each handle in the file.*/
    sm_p->u.io.small_io_ctx = malloc(attr->u.meta.dfile_count *
                                     sizeof(*sm_p->u.io.small_io_ctx));
    if (!sm_p->u.io.small_io_ctx)
    {
        PINT_msgpairarray_destroy(&sm_p->msgarray_op);
        js_p->error_code = -PVFS_ENOMEM;
        return SM_ACTION_COMPLETE;
    }
    memset(sm_p->u.io.small_io_ctx,0,sizeof(*sm_p->u.io.small_io_ctx) *
                                     attr->u.meta.dfile_count);


    foreach_msgpair(&sm_p->msgarray_op, msg_p, i)
    {
        datafile_handle = attr->u.meta.dfile_array[
            sm_p->u.io.datafile_index_array[i]];

        gossip_debug(GOSSIP_IO_DEBUG, "   small_io_setup_msgpairs: "
                     "handle: %llu\n", llu(datafile_handle));

        if(sm_p->u.io.io_type == PVFS_IO_WRITE)
        {
            PINT_Request_state * file_req_state = NULL;
            PINT_Request_state * mem_req_state = NULL;
            PINT_request_file_data file_data;
            PINT_Request_result result;

            memset(&file_data, 0, sizeof(PINT_request_file_data));
            file_data.server_ct = attr->u.meta.dfile_count;
            file_data.fsize = 0;
            file_data.dist = attr->u.meta.dist;
            file_data.extend_flag = 1;
            result.segmax = IO_MAX_REGIONS;

            result.bytemax = PINT_REQUEST_TOTAL_BYTES(sm_p->u.io.mem_req);
            file_req_state = PINT_new_request_state(sm_p->u.io.file_req);
            mem_req_state = PINT_new_request_state(sm_p->u.io.mem_req);

            PINT_REQUEST_STATE_SET_TARGET(file_req_state, 
                                          sm_p->u.io.file_req_offset);

            PINT_REQUEST_STATE_SET_FINAL(file_req_state, 
                                         sm_p->u.io.file_req_offset + 
                                         result.bytemax);

            file_data.server_nr = sm_p->u.io.datafile_index_array[i]; 

            result.segs = 0;
            result.bytes = 0;
            result.offset_array = msg_p->req.u.small_io.offsets;
            result.size_array = msg_p->req.u.small_io.sizes;
            msg_p->req.u.small_io.buffer = sm_p->u.io.buffer;

            ret = PINT_process_request(
                file_req_state, mem_req_state,
                &file_data,
                &result,
                PINT_CLIENT);
            if(ret < 0)
            {
                js_p->error_code = ret;
                PINT_free_request_state(file_req_state);
                PINT_free_request_state(mem_req_state);
                return SM_ACTION_COMPLETE;
            }

            regions = result.segs;

            PINT_free_request_state(file_req_state);
            PINT_free_request_state(mem_req_state);
        }

        /* if this is a write operation, the appropriate offset and size
         * arrays will have been filled in by the request processing above.
         * reads don't require processing of the memory request until
         * the response.  
         */ 
        PINT_SERVREQ_SMALL_IO_FILL(
            msg_p->req,
            *sm_p->cred_p,
            sm_p->object_ref.fs_id,
            datafile_handle,
            sm_p->u.io.io_type,
            sm_p->u.io.datafile_index_array[i], 
            attr->u.meta.dfile_count,
            attr->u.meta.dist,
            sm_p->u.io.file_req,
            sm_p->u.io.file_req_offset,
            regions,
            PINT_REQUEST_TOTAL_BYTES(sm_p->u.io.mem_req),
            sm_p->hints);

        msg_p->fs_id  = sm_p->object_ref.fs_id;
        msg_p->handle = datafile_handle;

        /*if we are processing a read request and the source file has mirrored
         *handles, then bypass msgpairarray's retry mechanism.  SMALL-IO will
         *prepare another set of msgpairs using the mirrors and then retry.
        */
        if (sm_p->u.io.io_type == PVFS_IO_READ &&
            attr->mask & PVFS_ATTR_META_MIRROR_DFILES)
        {
            msg_p->retry_flag = PVFS_MSGPAIR_NO_RETRY;  
        }
        else
        {
            msg_p->retry_flag = PVFS_MSGPAIR_RETRY;
        }
        msg_p->comp_fn = small_io_completion_fn;

        ret = PINT_cached_config_map_to_server(
            &msg_p->svr_addr, datafile_handle,
            sm_p->object_ref.fs_id);
        if(ret < 0)
        {
            gossip_lerr("Failed to map data server address\n");
            js_p->error_code = ret;
            return SM_ACTION_COMPLETE;
        }

        /*store the original datahandle for later use.*/
        server_nr = msg_p->req.u.small_io.server_nr;
        sm_p->u.io.small_io_ctx[server_nr].original_datahandle = msg_p->handle;
    }

    js_p->error_code = 0;

    PINT_sm_push_frame(smcb, 0, &sm_p->msgarray_op);
    return SM_ACTION_COMPLETE;
}

/**
 * We assume that the response buffer hasn't been freed yet (before
 * the completion function is called.   The msgpairarray.sm doesn't
 * free the response buffer until after the completion function is
 * called.
 */
static int small_io_completion_fn(void * user_args,
                                  struct PVFS_server_resp * resp_p,
                                  int index)
{
    struct PINT_smcb *smcb = (struct PINT_smcb *)user_args;
    struct PINT_client_sm *sm_p = PINT_sm_frame(smcb, PINT_MSGPAIR_PARENT_SM);
    PINT_sm_msgarray_op   *mop   = &(sm_p->msgarray_op);
    PINT_sm_msgpair_state *msg_p = &(mop->msgarray[index]);
    PINT_client_small_io_ctx *ctx = 
         &(sm_p->u.io.small_io_ctx[msg_p->req.u.small_io.server_nr]);
    uint32_t server_nr = msg_p->req.u.small_io.server_nr;
#ifdef WIN32
    PVFS_object_attr *attr = &(sm_p->getattr.attr);
    PVFS_metafile_attr *meta = &(attr->u.meta);
#else
    PVFS_object_attr *attr __attribute__((unused)) = &(sm_p->getattr.attr);
    PVFS_metafile_attr *meta __attribute__((unused)) = &(attr->u.meta);
#endif

    int ret = 0;

    assert(resp_p->op == PVFS_SERV_SMALL_IO);

    if(resp_p->status != 0)
    {
        return resp_p->status;
    }

    if(resp_p->u.small_io.io_type == PVFS_IO_READ)
    {
        PVFS_size sizes[IO_MAX_REGIONS];
        PVFS_offset offsets[IO_MAX_REGIONS];
        PVFS_object_attr * attr = &sm_p->getattr.attr;
        PINT_request_file_data fdata;
        PINT_Request_result result;
        PINT_Request_state * file_req_state;
        PINT_Request_state * mem_req_state;
        int i = 0;
        int done = 0;
        PVFS_size bytes_processed = 0;

        memset(&fdata, 0, sizeof(fdata));

        if(resp_p->u.small_io.result_size != 0)
        {
            memset(&fdata, 0, sizeof(PINT_request_file_data));
            fdata.server_ct = attr->u.meta.dfile_count;

            fdata.server_nr = server_nr;
            fdata.dist = attr->u.meta.dist;
            fdata.fsize = resp_p->u.small_io.bstream_size;

            result.segmax = IO_MAX_REGIONS;
            result.bytemax = resp_p->u.small_io.result_size;
            result.size_array = sizes;
            result.offset_array = offsets;

            file_req_state = PINT_new_request_state(sm_p->u.io.file_req);
            mem_req_state = PINT_new_request_state(sm_p->u.io.mem_req);

            PINT_REQUEST_STATE_SET_TARGET(file_req_state, 
                                          sm_p->u.io.file_req_offset);
            PINT_REQUEST_STATE_SET_FINAL(
                file_req_state, sm_p->u.io.file_req_offset + 
                PINT_REQUEST_TOTAL_BYTES(sm_p->u.io.mem_req));

            do
            {
                result.segs = 0;
                result.bytes = 0;

                ret = PINT_process_request(
                    file_req_state,
                    mem_req_state,
                    &fdata,
                    &result,
                    PINT_CLIENT);
                if(ret < 0)
                {
                    gossip_err("Failed processing request in small I/O read\n");
                    return ret;
                }

                for(i = 0; i < result.segs && !done; ++i)
                {
                    int tmp_size;
                    char * src_ptr;
                    char * dest_ptr;

                    dest_ptr = (char *)sm_p->u.io.buffer + offsets[i];
                    src_ptr = (char *)resp_p->u.small_io.buffer + 
                        bytes_processed;

                    if((bytes_processed + sizes[i]) <= 
                       resp_p->u.small_io.result_size)
                    {
                        tmp_size = sizes[i];
                    }
                    else
                    {
                        tmp_size = resp_p->u.small_io.result_size - 
                            bytes_processed;
                        done = 1;
                    }

                    memcpy(dest_ptr, src_ptr, sizes[i]);
                    bytes_processed += tmp_size;
                }
            } while(!PINT_REQUEST_DONE(file_req_state) && !done);

            if(resp_p->u.small_io.result_size != bytes_processed)
            {
                gossip_err("size of bytes copied to user buffer "
                           "(%llu) do not match size of response (%llu)\n", 
                           llu(bytes_processed),
                           llu(resp_p->u.small_io.result_size));
                return -PVFS_EINVAL;
            }
            PINT_free_request_state(file_req_state);
            PINT_free_request_state(mem_req_state);
        }
    } /*if PVFS_IO_READ*/

    sm_p->u.io.dfile_size_array[server_nr] = resp_p->u.small_io.bstream_size;
    //sm_p->u.io.dfile_size_array[index] = resp_p->u.small_io.bstream_size;

    sm_p->u.io.total_size += resp_p->u.small_io.result_size;

    /* Let's SMALL-IO know that the msg completed. */
    ctx->msg_completed = 1;

    /* To test fail-over with small-io, uncomment the following code.  This
     * will force each primary handle to have each of its mirrored handles
     * tried on a READ io.  If you are testing a file with many primary
     * handles and/or many copies and don't want to wade through such a large
     * test, then don't set the retry-limit.  By default, it is normally set
     * at 5.  You can tweak this value in the pvfs2-fs.conf file, if you
     * want.
    */

    gossip_debug(GOSSIP_IO_DEBUG,"handle=%llu \toperation=%d \toffset=%ld "
                             "\taggregate_size=%ld\n",
                            llu(msg_p->req.u.small_io.handle),
                            msg_p->req.u.small_io.io_type,
                            ((long int)msg_p->req.u.small_io.file_req_offset),
                            ((long int)msg_p->req.u.small_io.aggregate_size));

/*
    if (   (sm_p->u.io.io_type == PVFS_IO_READ) 
        && (attr->mask & PVFS_ATTR_META_MIRROR_DFILES) 
                               == PVFS_ATTR_META_MIRROR_DFILES
        && (sm_p->u.io.retry_count < mop->params.retry_limit))
    {
       mop->params.retry_limit = meta->mirror_copies_count;
       ctx->msg_completed = 0;
    } 
*/

    return 0;
}


static int small_io_check_for_retries( struct PINT_smcb *smcb
                                     , job_status_s *js_p)
{
#ifndef WIN32
    gossip_debug(GOSSIP_MIRROR_DEBUG,"Executing %s..\n",__func__);
#endif

    struct PINT_client_sm *sm_p = PINT_sm_frame(smcb, PINT_FRAME_CURRENT);
    struct PVFS_object_attr *attr = &(sm_p->getattr.attr);
    PVFS_metafile_attr *meta = &(attr->u.meta);
    PINT_client_small_io_ctx *ctx = NULL;
    PINT_sm_msgarray_op *mop = &sm_p->msgarray_op;
    PINT_sm_msgpair_state *msgarray = mop->msgarray;
    PINT_sm_msgpair_state *msg = NULL;
    PINT_sm_msgpair_state *new_msg = NULL;
    PINT_sm_msgarray_op new_mop = {{0},0,0,{0}};
    char *enc_req_bytes = NULL;

    uint32_t retry_msg_count = 0;
    uint32_t index = 0;
    uint32_t copies = 0;
    uint32_t server_nr = 0;
    int i   = 0;
    int j   = 0;
    int k   = 0;
    int ret = 0;

#ifdef WIN32
    gossip_debug(GOSSIP_MIRROR_DEBUG,"Executing %s..\n",__func__);
#endif
    /*if we are processing a write request, then msgpairarray handles retries.
     *if we are processing a read and the source file is mirrored, then
     *SMALL-IO handles the retries.
    */
    if (sm_p->u.io.io_type == PVFS_IO_WRITE ||
        ((attr->mask & PVFS_ATTR_META_MIRROR_DFILES) != 
          PVFS_ATTR_META_MIRROR_DFILES))
    {
       return SM_ACTION_COMPLETE;
    }

    /* Do any messages need to be retried? */
    for (i=0; i<mop->count; i++)
    {
        server_nr = msgarray[i].req.u.small_io.server_nr;
        ctx = &sm_p->u.io.small_io_ctx[server_nr];
        if (!ctx->msg_completed)
            retry_msg_count++;
    }

    /* no retries needed */
    if (!retry_msg_count)
    {
        return SM_ACTION_COMPLETE;
    }

    /* do we have any retries available? */
    if (sm_p->u.io.retry_count >= mop->params.retry_limit)
    {
        return SM_ACTION_COMPLETE;
    }

    /* okay. let's setup new msgpairs to retry. we will modify the incomplete 
     * msg pairs stored in msgarray and then copy them into a new msgarray 
     * before calling msgpairarray.sm.
    */
    for (i=0; i<mop->count; i++)
    {
        msg = &msgarray[i];
        server_nr = msg->req.u.small_io.server_nr;
        ctx = &sm_p->u.io.small_io_ctx[server_nr];
     
        /* don't process completed messages */
        if (ctx->msg_completed)
           continue;

        /* for incomplete messages, cleanup memory, if necessary */
        enc_req_bytes = (char *)&(msg->encoded_req);
        for (k=0; k<sizeof(msg->encoded_req); k++)
        {
           if (enc_req_bytes[k] != '\0')
           {
              PINT_encode_release(&(msg->encoded_req),PINT_ENCODE_REQ);
              break;
           }
        }/*end for*/

        if (msg->encoded_resp_p)
        {
            BMI_memfree(msg->svr_addr
                       ,msg->encoded_resp_p
                       ,msg->max_resp_sz
                       ,BMI_RECV);
        }
        
        /* Should we use the original datahandle? */
        if (ctx->retry_original)
        {
            ctx->retry_original = 0;
            msg->handle                = ctx->original_datahandle;
            msg->req.u.small_io.handle = ctx->original_datahandle;
            msg->svr_addr = 0;
            ret = PINT_cached_config_map_to_server(&msg->svr_addr
                                                  ,msg->handle
                                                  ,msg->fs_id);
            if (ret)
            {
               gossip_lerr("Unable to determine the server address "
                           "for this handle (%llu)"
                           ,llu(msg->handle));
               js_p->error_code = ret;
               return SM_ACTION_COMPLETE;
            }
            continue;
        }/*end retry_original*/

        /* get next mirrored handle.  note:  if a mirrored handle is zero, then
         * this means that the creation of this mirrored object failed for its
         * particular server.  if so, then get the next valid handle.  as a 
         * last resort, retry the original handle.
        */
        copies = ctx->current_copies_count;
        for (;copies < meta->mirror_copies_count; copies++)
        {
            index = (copies*meta->dfile_count) + server_nr;
            if (meta->mirror_dfile_array[index] != 0)
            {  /* we have found a valid mirrored handle */
               msg->handle = meta->mirror_dfile_array[index];
               break;
            }
        }

        /* if we haven't found a valid mirrored handle, retry the original
         * datahandle.
        */
        if ( copies == meta->mirror_copies_count )
        {
           msg->handle = ctx->original_datahandle;
           ctx->retry_original = 0;
           ctx->current_copies_count = 0;
           sm_p->u.io.retry_count++;
           msg->req.u.small_io.handle = ctx->original_datahandle;
           msg->svr_addr = 0;
           ret=PINT_cached_config_map_to_server(&(msg->svr_addr)
                                               ,msg->handle
                                               ,msg->fs_id);
           if (ret)
           {
              gossip_lerr("Unable to determine the server address "
                          "for this handle (%llu)"
                          ,llu(msg->handle));
              js_p->error_code = ret;
              return SM_ACTION_COMPLETE;
           }
           continue;
        }/*end if we have to use the original*/

        /* Otherwise, use the discovered mirrored handle */
        msg->req.u.small_io.handle = msg->handle;
        msg->svr_addr = 0;
        ret=PINT_cached_config_map_to_server(&(msg->svr_addr)
                                            ,msg->handle
                                            ,msg->fs_id);
        if (ret)
        {
           gossip_lerr("Unable to determine the server address "
                       "for this handle (%llu)"
                       ,llu(msg->handle));
           js_p->error_code = ret;
           return SM_ACTION_COMPLETE;
        }

        /* and setup for the next retry event */
        ctx->current_copies_count++;
        if (ctx->current_copies_count == meta->mirror_copies_count)
        {
           ctx->current_copies_count = 0;
           ctx->retry_original = 1;
           sm_p->u.io.retry_count++;
        }
    }/*end for each msgpair*/

    /* Now, create a new msgpair array and populate from the above modified
     * messages.
    */
    ret = PINT_msgpairarray_init(&new_mop,retry_msg_count);
    if (ret)
    {
        gossip_lerr("Unable to initialize msgarray_op:new_op\n");
        js_p->error_code = ret;
        return SM_ACTION_COMPLETE;
    }

    /* populate the new msgarray with the modified messages */
    for (i=0, j=0; i<mop->count && j<new_mop.count; i++)
    {
        msg = &msgarray[i];
        server_nr = msg->req.u.small_io.server_nr;
        ctx = &sm_p->u.io.small_io_ctx[server_nr];
     
        /* don't populate with completed messages */
        if (ctx->msg_completed)
           continue;

        new_msg = &new_mop.msgarray[j];
        j++;

        new_msg->fs_id       = msg->fs_id;
        new_msg->handle      = msg->handle;
        new_msg->comp_fn     = msg->comp_fn;
        new_msg->svr_addr    = msg->svr_addr;
        new_msg->req         = msg->req;
        new_msg->enc_type    = msg->enc_type;
        new_msg->retry_flag  = msg->retry_flag;
    }/*end for*/

    /* Destroy the old msgarray and substitute with the new. Params are left
     * in tact.
    */
    PINT_msgpairarray_destroy(mop);
    mop->count    = new_mop.count;
    mop->msgarray = new_mop.msgarray;
    mop->msgpair  = new_mop.msgpair;

    /* Push the msgarray_op and jump to msgpairarray.sm */
    PINT_sm_push_frame(smcb,0,mop);
    js_p->error_code=MIRROR_RETRY;
    return SM_ACTION_COMPLETE;
}/*end small_io_check_for_retries*/



static int small_io_cleanup(
    struct PINT_smcb *smcb, job_status_s *js_p)
{
    struct PINT_client_sm *sm_p = PINT_sm_frame(smcb, PINT_FRAME_CURRENT);

    PINT_msgpairarray_destroy(&sm_p->msgarray_op);

    /*release the ctx array; this array is allocated whether or not the 
     *file to read is mirrored.
    */
    free(sm_p->u.io.small_io_ctx);

    return SM_ACTION_COMPLETE;
}

/*
 * Local variables:
 *  mode: c
 *  c-indent-level: 4
 *  c-basic-offset: 4
 * End:
 *
 * vim: ft=c ts=8 sts=4 sw=4 expandtab
 */