bytemark/flexnbd-c
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Formatting fixup

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This commit is contained in:
Alex Young
2013-05-01 11:02:46 +01:00
parent 151b739e8d
commit e548cc53c8
1 changed files with 113 additions and 92 deletions
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205
src/proxy.c
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@@ -2,7 +2,7 @@
#include "readwrite.h" #include "readwrite.h"
#ifdef PREFETCH #ifdef PREFETCH
#include "prefetch.h" #include "prefetch.h"
#endif #endif
@@ -66,7 +66,7 @@ struct proxier* proxy_create(
out->upstream_fd = -1; out->upstream_fd = -1;
#ifdef PREFETCH #ifdef PREFETCH
out->prefetch = xmalloc( sizeof( struct prefetch ) ); out->prefetch = xmalloc( sizeof( struct prefetch ) );
#endif #endif
@@ -81,7 +81,7 @@ void proxy_destroy( struct proxier* proxy )
free( proxy->req_buf ); free( proxy->req_buf );
free( proxy->rsp_buf ); free( proxy->rsp_buf );
#ifdef PREFETCH #ifdef PREFETCH
free( proxy->prefetch ); free( proxy->prefetch );
#endif #endif
free( proxy ); free( proxy );
@@ -243,88 +243,101 @@ int proxy_run_request_upstream( struct proxier* proxy )
unsigned char* rsp_hdr_raw = proxy->rsp_buf; unsigned char* rsp_hdr_raw = proxy->rsp_buf;
unsigned char* rsp_data = proxy->rsp_buf + NBD_REPLY_SIZE; unsigned char* rsp_data = proxy->rsp_buf + NBD_REPLY_SIZE;
struct nbd_reply_raw* reply_raw = (struct nbd_reply_raw*) rsp_hdr_raw; struct nbd_reply_raw* reply_raw = (struct nbd_reply_raw*) rsp_hdr_raw;
struct nbd_request* request = &(proxy->req_hdr);
struct nbd_request* request = &(proxy->req_hdr);
#ifdef PREFETCH #ifdef PREFETCH
/* We only want to consider prefetching if we know we're not getting too much /* We only want to consider prefetching if we know we're not
* data back, if it's a read request, and if the prefetch won't try to read * getting too much data back, if it's a read request, and if
* past the end of the file. * the prefetch won't try to read past the end of the file.
*/ */
int prefetching = int prefetching =
request->len <= PREFETCH_BUFSIZE && request->len <= PREFETCH_BUFSIZE &&
request->type == REQUEST_READ && request->type == REQUEST_READ &&
(request->from + request->len * 2) <= proxy->upstream_size; (request->from + request->len * 2) <= proxy->upstream_size;
/* We pull the request out of the proxy struct, rewrite the /* We pull the request out of the proxy struct, rewrite the
* request size, and write it back. * request size, and write it back.
*/ */
if ( prefetching ) { if ( prefetching ) {
/* We need a malloc here because nbd_h2r_request craps /* We need a malloc here because nbd_h2r_request craps
* out if passed an address on the stack * out if passed an address on the stack
*/ */
struct nbd_request* rewrite_request = xmalloc( sizeof( struct nbd_request ) ); struct nbd_request* rewrite_request =
NULLCHECK( rewrite_request ); xmalloc( sizeof( struct nbd_request ) );
memcpy( rewrite_request, request, sizeof( struct nbd_request ) ); NULLCHECK( rewrite_request );
memcpy( rewrite_request,
request,
sizeof( struct nbd_request ) );
rewrite_request->len *= 2; rewrite_request->len *= 2;
debug( "Prefetching %d bytes", rewrite_request->len ); debug( "Prefetching %d bytes", rewrite_request->len );
nbd_h2r_request( rewrite_request, (struct nbd_request_raw *)proxy->req_buf ); nbd_h2r_request( rewrite_request,
free( rewrite_request ); (struct nbd_request_raw *)proxy->req_buf );
} free( rewrite_request );
}
#endif #endif
struct nbd_reply* reply = &(proxy->rsp_hdr); struct nbd_reply* reply = &(proxy->rsp_hdr);
size_t rsp_buf_size; size_t rsp_buf_size;
#ifdef PREFETCH #ifdef PREFETCH
if ( request->type == REQUEST_READ ){ if ( request->type == REQUEST_READ ){
/* See if we can respond with what's in our prefetch /* See if we can respond with what's in our prefetch
* cache * cache
*/ */
if( proxy->prefetch->is_full && if( proxy->prefetch->is_full &&
request->from == proxy->prefetch->from && request->from == proxy->prefetch->from &&
request->len == proxy->prefetch->len ) { request->len == proxy->prefetch->len ) {
/* HUZZAH! A match! */ /* HUZZAH! A match! */
debug( "Prefetch hit!" ); debug( "Prefetch hit!" );
/* First build a reply header */ /* First build a reply header */
struct nbd_reply prefetch_reply = {REPLY_MAGIC, 0, "01234567"}; struct nbd_reply prefetch_reply =
memcpy( &(prefetch_reply.handle), request->handle, 8 ); {REPLY_MAGIC, 0, "01234567"};
memcpy( &(prefetch_reply.handle), request->handle, 8 );
/* now copy it into the response */ /* now copy it into the response */
nbd_h2r_reply( &prefetch_reply, reply_raw ); nbd_h2r_reply( &prefetch_reply, reply_raw );
/* and the data */ /* and the data */
memcpy( rsp_data, proxy->prefetch->buffer, proxy->prefetch->len ); memcpy( rsp_data,
proxy->prefetch->buffer,
proxy->prefetch->len );
proxy->rsp_buf_size = NBD_REPLY_SIZE + proxy->prefetch->len; proxy->rsp_buf_size =
NBD_REPLY_SIZE + proxy->prefetch->len;
/* return early, our work here is done */ /* return early, our work here is done */
return 1; return 1;
} }
} }
else { else {
/* Safety catch. If we're sending a write request, we /* Safety catch. If we're sending a write request, we
* blow away the cache. This is very pessimistic, but * blow away the cache. This is very pessimistic, but
* it's simpler (and therefore safer) than working out * it's simpler (and therefore safer) than working out
* whether we can keep it or not. * whether we can keep it or not.
*/ */
debug( "Blowing away prefetch cache on type %d request.", request->type ); debug("Blowing away prefetch cache on type %d request.",
proxy->prefetch->is_full = 0; request->type);
} proxy->prefetch->is_full = 0;
#endif }
#endif
if ( writeloop( proxy->upstream_fd, proxy->req_buf, proxy->req_buf_size ) == -1 ) { if ( -1 == writeloop( proxy->upstream_fd,
proxy->req_buf,
proxy->req_buf_size ) ) {
warn( "Failed to send request to upstream" ); warn( "Failed to send request to upstream" );
goto disconnect; goto disconnect;
} }
if ( readloop( proxy->upstream_fd, rsp_hdr_raw, NBD_REPLY_SIZE ) == -1 ) { if ( -1 == readloop( proxy->upstream_fd,
rsp_hdr_raw,
NBD_REPLY_SIZE ) ) {
debug( "Failed to get reply header from upstream" ); debug( "Failed to get reply header from upstream" );
goto disconnect; goto disconnect;
} }
nbd_r2h_reply( reply_raw, reply ); nbd_r2h_reply( reply_raw, reply );
@@ -332,51 +345,59 @@ int proxy_run_request_upstream( struct proxier* proxy )
if ( reply->magic != REPLY_MAGIC ) { if ( reply->magic != REPLY_MAGIC ) {
debug( "Reply magic is incorrect" ); debug( "Reply magic is incorrect" );
goto disconnect; goto disconnect;
} }
debug( "NBD reply received from upstream. Response code: %"PRIu32, reply->error ); debug("NBD reply received from upstream. Response code: %"PRIu32,
reply->error );
if ( reply->error != 0 ) { if ( reply->error != 0 ) {
warn( "NBD error returned from upstream: %"PRIu32, reply->error ); warn( "NBD error returned from upstream: %"PRIu32,
reply->error );
} }
if ( reply->error == 0 && request->type == REQUEST_READ ) { if ( reply->error == 0 && request->type == REQUEST_READ ) {
#ifdef PREFETCH #ifdef PREFETCH
if (readloop( proxy->upstream_fd, rsp_data, request->len ) == -1 ) { if ( -1 == readloop( proxy->upstream_fd,
debug( "Failed to get reply data from upstream" ); rsp_data,
goto disconnect; request->len ) ) {
} debug( "Failed to get reply data from upstream" );
goto disconnect;
}
if ( prefetching ) {
if ( prefetching ) { if ( -1 == readloop( proxy->upstream_fd,
if ( readloop( proxy->upstream_fd, &(proxy->prefetch->buffer), request->len ) == -1 ) { &(proxy->prefetch->buffer),
debug( "Failed to get prefetch reply data from upstream" ); request->len ) ) {
goto disconnect; debug( "Failed to get prefetch reply data "
} "from upstream" );
proxy->prefetch->from = request->from + request->len; goto disconnect;
proxy->prefetch->len = request->len; }
proxy->prefetch->is_full = 1; proxy->prefetch->from = request->from + request->len;
} proxy->prefetch->len = request->len;
proxy->prefetch->is_full = 1;
}
#else #else
if (readloop( proxy->upstream_fd, rsp_data, request->len ) == -1 ) { if ( -1 == readloop( proxy->upstream_fd,
debug( "Failed to get reply data from upstream" ); rsp_data,
goto disconnect; request->len ) ) {
} debug( "Failed to get reply data from upstream" );
goto disconnect;
}
#endif #endif
rsp_buf_size += request->len; rsp_buf_size += request->len;
} }
proxy->rsp_buf_size = rsp_buf_size; proxy->rsp_buf_size = rsp_buf_size;
return 1; return 1;
disconnect: disconnect:
proxy_disconnect_from_upstream( proxy ); proxy_disconnect_from_upstream( proxy );
#ifdef PREFETCH #ifdef PREFETCH
proxy->prefetch->is_full = 0; proxy->prefetch->is_full = 0;
#endif #endif
return 0; return 0;
} }
/* Write an NBD reply back downstream. Return 0 on failure, 1 on success. */ /* Write an NBD reply back downstream. Return 0 on failure, 1 on success. */