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-rw-r--r--src/server/net.c266
1 files changed, 148 insertions, 118 deletions
diff --git a/src/server/net.c b/src/server/net.c
index 9abe221..eb51d29 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -3,7 +3,7 @@
*
* Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
*
- * This file may be licensed under the terms of of the
+ * This file may be licensed under the terms of the
* GNU General Public License Version 2 (the ``GPL'').
*
* Software distributed under the License is distributed
@@ -24,11 +24,12 @@
#include "locks.h"
#include "rpc.h"
#include "altservers.h"
+#include "reference.h"
-#include "../shared/sockhelper.h"
-#include "../shared/timing.h"
-#include "../shared/protocol.h"
-#include "../serialize.h"
+#include <dnbd3/shared/sockhelper.h>
+#include <dnbd3/shared/timing.h>
+#include <dnbd3/shared/protocol.h>
+#include <dnbd3/shared/serialize.h>
#include <assert.h>
@@ -43,6 +44,7 @@
#include <jansson.h>
#include <inttypes.h>
#include <stdatomic.h>
+#include <signal.h>
static dnbd3_client_t *_clients[SERVER_MAX_CLIENTS];
static int _num_clients = 0;
@@ -56,11 +58,12 @@ static atomic_uint_fast64_t totalBytesSent = 0;
static bool addToList(dnbd3_client_t *client);
static void removeFromList(dnbd3_client_t *client);
static dnbd3_client_t* freeClientStruct(dnbd3_client_t *client);
+static void uplinkCallback(void *data, uint64_t handle, uint64_t start, uint32_t length, const char *buffer);
static inline bool recv_request_header(int sock, dnbd3_request_t *request)
{
ssize_t ret, fails = 0;
-#ifdef AFL_MODE
+#ifdef DNBD3_SERVER_AFL
sock = 0;
#endif
// Read request header from socket
@@ -87,7 +90,7 @@ static inline bool recv_request_header(int sock, dnbd3_request_t *request)
static inline bool recv_request_payload(int sock, uint32_t size, serialized_buffer_t *payload)
{
-#ifdef AFL_MODE
+#ifdef DNBD3_SERVER_AFL
sock = 0;
#endif
if ( size == 0 ) {
@@ -111,7 +114,7 @@ static inline bool recv_request_payload(int sock, uint32_t size, serialized_buff
* Send reply with optional payload. payload can be null. The caller has to
* acquire the sendMutex first.
*/
-static inline bool send_reply(int sock, dnbd3_reply_t *reply, void *payload)
+static inline bool send_reply(int sock, dnbd3_reply_t *reply, const void *payload)
{
const uint32_t size = reply->size;
fixup_reply( *reply );
@@ -145,18 +148,19 @@ static inline bool sendPadding( const int fd, uint32_t bytes )
void net_init()
{
- mutex_init( &_clients_lock );
+ mutex_init( &_clients_lock, LOCK_CLIENT_LIST );
}
void* net_handleNewConnection(void *clientPtr)
{
dnbd3_client_t * const client = (dnbd3_client_t *)clientPtr;
dnbd3_request_t request;
+ client->thread = pthread_self();
// Await data from client. Since this is a fresh connection, we expect data right away
sock_setTimeout( client->sock, _clientTimeout );
do {
-#ifdef AFL_MODE
+#ifdef DNBD3_SERVER_AFL
const int ret = (int)recv( 0, &request, sizeof(request), MSG_WAITALL );
#else
const int ret = (int)recv( client->sock, &request, sizeof(request), MSG_WAITALL );
@@ -186,14 +190,15 @@ void* net_handleNewConnection(void *clientPtr)
}
} while (0);
// Fully init client struct
- mutex_init( &client->lock );
- mutex_init( &client->sendMutex );
+ mutex_init( &client->lock, LOCK_CLIENT );
+ mutex_init( &client->sendMutex, LOCK_CLIENT_SEND );
mutex_lock( &client->lock );
host_to_string( &client->host, client->hostName, HOSTNAMELEN );
client->hostName[HOSTNAMELEN-1] = '\0';
mutex_unlock( &client->lock );
client->bytesSent = 0;
+ client->relayedCount = 0;
if ( !addToList( client ) ) {
freeClientStruct( client );
@@ -204,6 +209,7 @@ void* net_handleNewConnection(void *clientPtr)
dnbd3_reply_t reply;
dnbd3_image_t *image = NULL;
+ dnbd3_cache_map_t *cache = NULL;
int image_file = -1;
int num;
@@ -212,7 +218,6 @@ void* net_handleNewConnection(void *clientPtr)
serialized_buffer_t payload;
uint16_t rid, client_version;
- uint64_t start, end;
dnbd3_server_entry_t server_list[NUMBER_SERVERS];
@@ -229,7 +234,7 @@ void* net_handleNewConnection(void *clientPtr)
rid = serializer_get_uint16( &payload );
const uint8_t flags = serializer_get_uint8( &payload );
client->isServer = ( flags & FLAGS8_SERVER );
- if ( request.size < 3 || !image_name || client_version < MIN_SUPPORTED_CLIENT ) {
+ if ( unlikely( request.size < 3 || !image_name || client_version < MIN_SUPPORTED_CLIENT ) ) {
if ( client_version < MIN_SUPPORTED_CLIENT ) {
logadd( LOG_DEBUG1, "Client %s too old", client->hostName );
} else {
@@ -243,7 +248,7 @@ void* net_handleNewConnection(void *clientPtr)
// We're a proxy, client is another proxy, we don't do BGR, but connecting proxy does...
// Reject, as this would basically force this proxy to do BGR too.
image = image_get( image_name, rid, true );
- if ( image != NULL && image->cache_map != NULL ) {
+ if ( image != NULL && image->ref_cacheMap != NULL ) {
// Only exception is if the image is complete locally
image = image_release( image );
}
@@ -255,27 +260,28 @@ void* net_handleNewConnection(void *clientPtr)
// No BGR mismatch, but don't lookup if image is unknown locally
image = image_get( image_name, rid, true );
}
- mutex_lock( &client->lock );
client->image = image;
- mutex_unlock( &client->lock );
- if ( image == NULL ) {
+ atomic_thread_fence( memory_order_release );
+ if ( unlikely( image == NULL ) ) {
//logadd( LOG_DEBUG1, "Client requested non-existent image '%s' (rid:%d), rejected\n", image_name, (int)rid );
- } else if ( !image->working ) {
+ } else if ( unlikely( image->problem.read || image->problem.changed ) ) {
logadd( LOG_DEBUG1, "Client %s requested non-working image '%s' (rid:%d), rejected\n",
client->hostName, image_name, (int)rid );
} else {
- bool penalty;
// Image is fine so far, but occasionally drop a client if the uplink for the image is clogged or unavailable
bOk = true;
- if ( image->cache_map != NULL ) {
- mutex_lock( &image->lock );
- if ( image->uplink == NULL || image->uplink->cacheFd == -1 || image->uplink->queueLen > SERVER_UPLINK_QUEUELEN_THRES ) {
+ if ( image->ref_cacheMap != NULL ) {
+ if ( image->problem.queue || image->problem.write ) {
bOk = ( rand() % 4 ) == 1;
}
- penalty = bOk && image->uplink != NULL && image->uplink->cacheFd == -1;
- mutex_unlock( &image->lock );
- if ( penalty ) { // Wait 100ms if local caching is not working so this
- usleep( 100000 ); // server gets a penalty and is less likely to be selected
+ if ( bOk ) {
+ if ( image->problem.write ) { // Wait 100ms if local caching is not working so this
+ usleep( 100000 ); // server gets a penalty and is less likely to be selected
+ }
+ if ( image->problem.uplink ) {
+ // Penaltize depending on completeness, if no uplink is available
+ usleep( ( 100 - image->completenessEstimate ) * 100 );
+ }
}
}
if ( bOk ) {
@@ -284,6 +290,7 @@ void* net_handleNewConnection(void *clientPtr)
if ( !client->isServer ) {
// Only update immediately if this is a client. Servers are handled on disconnect.
timing_get( &image->atime );
+ image->accessed = true;
}
mutex_unlock( &image->lock );
serializer_reset_write( &payload );
@@ -301,7 +308,7 @@ void* net_handleNewConnection(void *clientPtr)
}
}
- if ( bOk ) {
+ if ( likely( bOk ) ) {
// add artificial delay if applicable
if ( client->isServer && _serverPenalty != 0 ) {
usleep( _serverPenalty );
@@ -311,95 +318,62 @@ void* net_handleNewConnection(void *clientPtr)
// client handling mainloop
while ( recv_request_header( client->sock, &request ) ) {
if ( _shutdown ) break;
- switch ( request.cmd ) {
+ if ( likely ( request.cmd == CMD_GET_BLOCK ) ) {
- case CMD_GET_BLOCK:;
const uint64_t offset = request.offset_small; // Copy to full uint64 to prevent repeated masking
- if ( offset >= image->virtualFilesize ) {
+ reply.handle = request.handle;
+ if ( unlikely( offset >= image->virtualFilesize ) ) {
// Sanity check
logadd( LOG_WARNING, "Client %s requested non-existent block", client->hostName );
reply.size = 0;
reply.cmd = CMD_ERROR;
send_reply( client->sock, &reply, NULL );
- break;
+ continue;
}
- if ( offset + request.size > image->virtualFilesize ) {
+ if ( unlikely( offset + request.size > image->virtualFilesize ) ) {
// Sanity check
logadd( LOG_WARNING, "Client %s requested data block that extends beyond image size", client->hostName );
reply.size = 0;
reply.cmd = CMD_ERROR;
send_reply( client->sock, &reply, NULL );
- break;
+ continue;
+ }
+
+ if ( cache == NULL ) {
+ cache = ref_get_cachemap( image );
}
- if ( request.size != 0 && image->cache_map != NULL ) {
+ if ( request.size != 0 && cache != NULL ) {
// This is a proxyed image, check if we need to relay the request...
- start = offset & ~(uint64_t)(DNBD3_BLOCK_SIZE - 1);
- end = (offset + request.size + DNBD3_BLOCK_SIZE - 1) & ~(uint64_t)(DNBD3_BLOCK_SIZE - 1);
- bool isCached = true;
- mutex_lock( &image->lock );
- // Check again as we only aquired the lock just now
- if ( image->cache_map != NULL ) {
- const uint64_t firstByteInMap = start >> 15;
- const uint64_t lastByteInMap = (end - 1) >> 15;
- uint64_t pos;
- // Middle - quick checking
- if ( isCached ) {
- pos = firstByteInMap + 1;
- while ( pos < lastByteInMap ) {
- if ( image->cache_map[pos] != 0xff ) {
- isCached = false;
- break;
- }
- ++pos;
+ const uint64_t start = offset & ~(uint64_t)(DNBD3_BLOCK_SIZE - 1);
+ const uint64_t end = (offset + request.size + DNBD3_BLOCK_SIZE - 1) & ~(uint64_t)(DNBD3_BLOCK_SIZE - 1);
+ if ( !image_isRangeCachedUnsafe( cache, start, end ) ) {
+ if ( unlikely( client->relayedCount > 250 ) ) {
+ logadd( LOG_DEBUG1, "Client is overloading uplink; throttling" );
+ for ( int i = 0; i < 100 && client->relayedCount > 200; ++i ) {
+ usleep( 10000 );
}
- }
- // First byte
- if ( isCached ) {
- pos = start;
- do {
- const int map_x = (pos >> 12) & 7; // mod 8
- const uint8_t bit_mask = (uint8_t)( 1 << map_x );
- if ( (image->cache_map[firstByteInMap] & bit_mask) == 0 ) {
- isCached = false;
- break;
- }
- pos += DNBD3_BLOCK_SIZE;
- } while ( firstByteInMap == (pos >> 15) && pos < end );
- }
- // Last byte - only check if request spans multiple bytes in cache map
- if ( isCached && firstByteInMap != lastByteInMap ) {
- pos = lastByteInMap << 15;
- while ( pos < end ) {
- assert( lastByteInMap == (pos >> 15) );
- const int map_x = (pos >> 12) & 7; // mod 8
- const uint8_t bit_mask = (uint8_t)( 1 << map_x );
- if ( (image->cache_map[lastByteInMap] & bit_mask) == 0 ) {
- isCached = false;
- break;
- }
- pos += DNBD3_BLOCK_SIZE;
+ if ( client->relayedCount > 250 ) {
+ logadd( LOG_WARNING, "Could not lower client's uplink backlog; dropping client" );
+ goto exit_client_cleanup;
}
}
- }
- mutex_unlock( &image->lock );
- if ( !isCached ) {
- if ( !uplink_request( client, request.handle, offset, request.size, request.hops ) ) {
- logadd( LOG_DEBUG1, "Could not relay uncached request from %s to upstream proxy, disabling image %s:%d",
+ client->relayedCount++;
+ if ( !uplink_requestClient( client, &uplinkCallback, request.handle, offset, request.size, request.hops ) ) {
+ client->relayedCount--;
+ logadd( LOG_DEBUG1, "Could not relay uncached request from %s to upstream proxy for image %s:%d",
client->hostName, image->name, image->rid );
- image->working = false;
goto exit_client_cleanup;
}
- break; // DONE, exit request.cmd switch
+ continue; // Reply arrives on uplink some time later, handle next request now
}
}
reply.cmd = CMD_GET_BLOCK;
reply.size = request.size;
- reply.handle = request.handle;
fixup_reply( reply );
- const bool lock = image->uplink != NULL;
+ const bool lock = image->uplinkref != NULL;
if ( lock ) mutex_lock( &client->sendMutex );
// Send reply header
if ( send( client->sock, &reply, sizeof(dnbd3_reply_t), (request.size == 0 ? 0 : MSG_MORE) ) != sizeof(dnbd3_reply_t) ) {
@@ -422,7 +396,7 @@ void* net_handleNewConnection(void *clientPtr)
// TODO: Should we consider EOPNOTSUPP on BSD for sendfile and fallback to read/write?
// Linux would set EINVAL or ENOSYS instead, which it unfortunately also does for a couple of other failures :/
// read/write would kill performance anyways so a fallback would probably be of little use either way.
-#ifdef AFL_MODE
+#ifdef DNBD3_SERVER_AFL
char buf[1000];
size_t cnt = realBytes - done;
if ( cnt > 1000 ) {
@@ -459,7 +433,7 @@ void* net_handleNewConnection(void *clientPtr)
}
if ( err == EBADF || err == EFAULT || err == EINVAL || err == EIO ) {
logadd( LOG_INFO, "Disabling %s:%d", image->name, image->rid );
- image->working = false;
+ image->problem.read = true;
}
}
goto exit_client_cleanup;
@@ -476,11 +450,20 @@ void* net_handleNewConnection(void *clientPtr)
if ( lock ) mutex_unlock( &client->sendMutex );
// Global per-client counter
client->bytesSent += request.size; // Increase counter for statistics.
- break;
+ continue;
+ }
+ // Any other command
+ // Release cache map every now and then, in case the image was replicated
+ // entirely. Will be re-grabbed on next CMD_GET_BLOCK otherwise.
+ if ( cache != NULL ) {
+ ref_put( &cache->reference );
+ cache = NULL;
+ }
+ switch ( request.cmd ) {
case CMD_GET_SERVERS:
// Build list of known working alt servers
- num = altservers_getListForClient( &client->host, server_list, NUMBER_SERVERS );
+ num = altservers_getListForClient( client, server_list, NUMBER_SERVERS );
reply.cmd = CMD_GET_SERVERS;
reply.size = (uint32_t)( num * sizeof(dnbd3_server_entry_t) );
mutex_lock( &client->sendMutex );
@@ -525,24 +508,27 @@ set_name: ;
logadd( LOG_ERROR, "Unknown command from client %s: %d", client->hostName, (int)request.cmd );
break;
- }
- }
- }
+ } // end switch
+ } // end loop
+ } // end bOk
exit_client_cleanup: ;
// First remove from list, then add to counter to prevent race condition
removeFromList( client );
totalBytesSent += client->bytesSent;
// Access time, but only if client didn't just probe
- if ( image != NULL ) {
+ if ( image != NULL && client->bytesSent > DNBD3_BLOCK_SIZE * 10 ) {
mutex_lock( &image->lock );
- if ( client->bytesSent > DNBD3_BLOCK_SIZE * 10 ) {
- timing_get( &image->atime );
- }
+ timing_get( &image->atime );
+ image->accessed = true;
mutex_unlock( &image->lock );
}
+ if ( cache != NULL ) {
+ ref_put( &cache->reference );
+ }
freeClientStruct( client ); // This will also call image_release on client->image
return NULL ;
fail_preadd: ;
+ // This is before we even initialized any mutex
close( client->sock );
free( client );
return NULL;
@@ -609,6 +595,12 @@ void net_getStats(int *clientCount, int *serverCount, uint64_t *bytesSent)
}
bs += client->bytesSent;
}
+ // Do this before unlocking the list, otherwise we might
+ // account for a client twice if it would disconnect after
+ // unlocking but before we add the count here.
+ if ( bytesSent != NULL ) {
+ *bytesSent = totalBytesSent + bs;
+ }
mutex_unlock( &_clients_lock );
if ( clientCount != NULL ) {
*clientCount = cc;
@@ -616,9 +608,6 @@ void net_getStats(int *clientCount, int *serverCount, uint64_t *bytesSent)
if ( serverCount != NULL ) {
*serverCount = sc;
}
- if ( bytesSent != NULL ) {
- *bytesSent = totalBytesSent + bs;
- }
}
void net_disconnectAll()
@@ -626,11 +615,10 @@ void net_disconnectAll()
int i;
mutex_lock( &_clients_lock );
for (i = 0; i < _num_clients; ++i) {
- if ( _clients[i] == NULL ) continue;
- dnbd3_client_t * const client = _clients[i];
- mutex_lock( &client->lock );
- if ( client->sock >= 0 ) shutdown( client->sock, SHUT_RDWR );
- mutex_unlock( &client->lock );
+ if ( _clients[i] == NULL )
+ continue;
+ shutdown( _clients[i]->sock, SHUT_RDWR );
+ pthread_kill( _clients[i]->thread, SIGINT );
}
mutex_unlock( &_clients_lock );
}
@@ -668,11 +656,19 @@ static void removeFromList(dnbd3_client_t *client)
{
int i;
mutex_lock( &_clients_lock );
- for ( i = _num_clients - 1; i >= 0; --i ) {
- if ( _clients[i] == client ) {
- _clients[i] = NULL;
+ if ( _num_clients != 0 ) {
+ for ( i = _num_clients - 1; i >= 0; --i ) {
+ if ( _clients[i] == client ) {
+ _clients[i] = NULL;
+ break;
+ }
+ }
+ if ( i != 0 && i + 1 == _num_clients ) {
+ do {
+ i--;
+ } while ( _clients[i] == NULL && i > 0 );
+ _num_clients = i + 1;
}
- if ( _clients[i] == NULL && i + 1 == _num_clients ) --_num_clients;
}
mutex_unlock( &_clients_lock );
}
@@ -686,17 +682,33 @@ static void removeFromList(dnbd3_client_t *client)
static dnbd3_client_t* freeClientStruct(dnbd3_client_t *client)
{
mutex_lock( &client->lock );
+ if ( client->image != NULL ) {
+ dnbd3_uplink_t *uplink = ref_get_uplink( &client->image->uplinkref );
+ if ( uplink != NULL ) {
+ if ( client->relayedCount != 0 ) {
+ uplink_removeEntry( uplink, client, &uplinkCallback );
+ }
+ ref_put( &uplink->reference );
+ }
+ if ( client->relayedCount != 0 ) {
+ logadd( LOG_DEBUG1, "Client has relayedCount == %"PRIu8" on disconnect..", client->relayedCount );
+ int i;
+ for ( i = 0; i < 1000 && client->relayedCount != 0; ++i ) {
+ usleep( 10000 );
+ }
+ if ( client->relayedCount != 0 ) {
+ logadd( LOG_WARNING, "Client relayedCount still %"PRIu8" after sleeping!", client->relayedCount );
+ }
+ }
+ }
mutex_lock( &client->sendMutex );
- if ( client->sock != -1 ) close( client->sock );
+ if ( client->sock != -1 ) {
+ close( client->sock );
+ }
client->sock = -1;
mutex_unlock( &client->sendMutex );
- if ( client->image != NULL ) {
- mutex_lock( &client->image->lock );
- if ( client->image->uplink != NULL ) uplink_removeClient( client->image->uplink, client );
- mutex_unlock( &client->image->lock );
- client->image = image_release( client->image );
- }
mutex_unlock( &client->lock );
+ client->image = image_release( client->image );
mutex_destroy( &client->lock );
mutex_destroy( &client->sendMutex );
free( client );
@@ -729,3 +741,21 @@ static bool addToList(dnbd3_client_t *client)
return true;
}
+static void uplinkCallback(void *data, uint64_t handle, uint64_t start UNUSED, uint32_t length, const char *buffer)
+{
+ dnbd3_client_t *client = (dnbd3_client_t*)data;
+ dnbd3_reply_t reply = {
+ .magic = dnbd3_packet_magic,
+ .cmd = buffer == NULL ? CMD_ERROR : CMD_GET_BLOCK,
+ .handle = handle,
+ .size = length,
+ };
+ mutex_lock( &client->sendMutex );
+ send_reply( client->sock, &reply, buffer );
+ if ( buffer == NULL ) {
+ shutdown( client->sock, SHUT_RDWR );
+ }
+ client->relayedCount--;
+ mutex_unlock( &client->sendMutex );
+}
+
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-04-29 17:33:39 +0200