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-rw-r--r--src/server/job.c80
1 files changed, 29 insertions, 51 deletions
diff --git a/src/server/job.c b/src/server/job.c
index cc3065c..b9e17f6 100644
--- a/src/server/job.c
+++ b/src/server/job.c
@@ -13,9 +13,7 @@
#include <sys/ioctl.h>
#include <linux/fs.h>
#include <pthread.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
+#include "sockhelper.h"
#include <glib/gslist.h>
@@ -136,7 +134,7 @@ static void connect_proxy_images()
msg.len = (uint16_t)sizeof(dnbd3_ioctl_t);
msg.read_ahead_kb = DEFAULT_READ_AHEAD_KB;
msg.is_server = TRUE;
- for (n = 0 ;; ++n)
+ for (n = 0 ;; ++n) // Iterate over all images
{
pthread_spin_lock(&_spinlock);
dnbd3_image_t *image = g_slist_nth_data(_dnbd3_images, n);
@@ -146,7 +144,7 @@ static void connect_proxy_images()
break;
}
if (image->working && image->cache_map && image->file)
- { // Check if cache is complete
+ { // Image is relayed and already connected, check if cache is complete
int complete = TRUE, j;
const int map_len_bytes = IMGSIZE_TO_MAPBYTES(image->filesize);
for (j = 0; j < map_len_bytes - 1; ++j)
@@ -157,8 +155,8 @@ static void connect_proxy_images()
break;
}
}
- if (complete)
- {
+ if (complete) // Every block except the last one is complete
+ { // Last one might need extra treatment if it's not a full byte
const int blocks_in_last_byte = (image->filesize >> 12) & 7;
uint8_t last_byte = 0;
if (blocks_in_last_byte == 0)
@@ -168,7 +166,7 @@ static void connect_proxy_images()
last_byte |= (1 << j);
complete = ((image->cache_map[map_len_bytes - 1] & last_byte) == last_byte);
}
- if (!complete)
+ if (!complete) // Image is not complete, finished handling it
{
pthread_spin_unlock(&_spinlock);
continue;
@@ -192,13 +190,14 @@ static void connect_proxy_images()
continue;
}
if (image->working || image->file || image->low_name == NULL)
- { // Nothing to do
+ { // Image is a local one, nothing to do
pthread_spin_unlock(&_spinlock);
continue;
}
+ // Image is relayed and not connected yet
char *devname = get_free_device();
if (devname == NULL)
- { // All devices busy
+ { // All devices busy, can't connect
pthread_spin_unlock(&_spinlock);
continue;
}
@@ -209,15 +208,15 @@ static void connect_proxy_images()
memcpy(servers, image->servers, sizeof(servers[0]) * NUMBER_SERVERS);
pthread_spin_unlock(&_spinlock);
int dh = open(devname, O_RDWR);
- if (dh < 0)
+ if (dh < 0) // Open device so we can issue ioctls to it
{
pthread_spin_lock(&_spinlock);
- return_free_device(devname);
+ return_free_device(devname); // Failed :-(
pthread_spin_unlock(&_spinlock);
continue;
}
for (s = 0; s < NUMBER_SERVERS; ++s)
- {
+ { // Try to connect to any of the alt servers known for that image
if (servers[s].host.type == 0)
continue;
// connect device
@@ -229,7 +228,9 @@ static void connect_proxy_images()
if (ioctl(dh, IOCTL_OPEN, &msg) < 0)
continue;
printf("[DEBUG] Connected! Adding alt servers...\n");
- // connected
+ // connected. we manually add all known alt servers to this
+ // device, so even if the initial server doesn't consider some
+ // of those as trusted servers, they are still used for failover/load balancing
for (++s; s < NUMBER_SERVERS; ++s)
{
if (servers[s].host.type == 0)
@@ -258,7 +259,10 @@ static void connect_proxy_images()
long long oct = 0;
int t, ret;
for (t = 0; t < 10 && dh >= 0; ++t)
- { // For some reason the ioctl might return 0 right after connecting
+ { // For some reason the getsize-ioctl might return 0 right after connecting
+ // No idea why this happen. Maybe the IOCTL_OPEN call returns before the
+ // connection is fully established, but I have no idea why.
+ // So let's retry a couple of times if it fails.
ret = ioctl(dh, BLKGETSIZE64, &oct);
if (ret == 0 && oct > 0)
break;
@@ -313,7 +317,7 @@ static void connect_proxy_images()
if (isworking && !(alloc_cache && image->cache_file))
{
image->working = TRUE;
- if (!image->cache_file)
+ if (!image->cache_file) // This should be removed. proxy with no cache is completely pointless.
memlogf("[WARNING] Proxy-Mode enabled without cache directory. This will most likely hurt performance.");
goto continue_with_next_image;
}
@@ -325,6 +329,8 @@ static void connect_proxy_images()
if (ch >= 0)
{
// Pre-allocate disk space
+ // TODO: Check if this has a performance impact on the rest of the server (ie. client lag)
+ // If so, do this gracefully by incrementing size and sleeping in between.
printf("[DEBUG] Pre-allocating disk space...\n");
lseek(ch, fs - 1, SEEK_SET);
write(ch, &ch, 1);
@@ -345,8 +351,9 @@ static void connect_proxy_images()
memlogf("[WARNING] Could not pre-allocate %s", cfname);
}
break;
- } // <-- end loop over servers
- // If this point is reached, replication was not successful
+ } // <-- end of loop over servers
+ // If this point is reached, setting up replication was not successful,
+ // so lock and free the filename allocated earlier, and return the device.
pthread_spin_lock(&_spinlock);
if (g_slist_find(_dnbd3_images, image) != NULL)
{
@@ -377,15 +384,9 @@ static void query_servers()
{
if (_trusted_servers == NULL)
return;
- struct timeval client_timeout, connect_timeout;
- client_timeout.tv_sec = 0;
- client_timeout.tv_usec = 500 * 1000;
- connect_timeout.tv_sec = 1;
- connect_timeout.tv_usec = 0;
int client_sock, num;
dnbd3_trusted_server_t *server;
dnbd3_host_t host;
- struct sockaddr_in addr4;
char xmlbuffer[MAX_RPC_PAYLOAD];
for (num = 0;; ++num)
{
@@ -401,33 +402,10 @@ static void query_servers()
host = server->host; // Copy host, in case server gets deleted by another thread
pthread_spin_unlock(&_spinlock);
// Connect
- if (host.type != AF_INET)
- {
- printf("[DEBUG] Unsupported addr type '%d', ignoring trusted server.\n", (int)host.type);
- continue;
- }
- // Create socket (Extend for IPv6)
- if ((client_sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
- {
- printf("[DEBUG] Error creating server-to-server socket.\n");
+ host.port = htons(ntohs(host.port) + 1); // RPC port is client port + 1
+ client_sock = sock_connect(&host, 800, 600);
+ if (client_sock == -1)
continue;
- }
- // Set host (IPv4)
- memset(&addr4, 0, sizeof(addr4));
- addr4.sin_family = AF_INET;
- memcpy(&addr4.sin_addr.s_addr, host.addr, 4);
- addr4.sin_port = htons(ntohs(host.port) + 1);
- // Connect to server
- setsockopt(client_sock, SOL_SOCKET, SO_RCVTIMEO, &connect_timeout, sizeof(connect_timeout));
- setsockopt(client_sock, SOL_SOCKET, SO_SNDTIMEO, &connect_timeout, sizeof(connect_timeout));
- if (connect(client_sock, (struct sockaddr *)&addr4, sizeof(addr4)) < 0)
- {
- printf("[DEBUG] Could not connect to other server...\n");
- goto communication_error;
- }
- // Apply read/write timeout
- setsockopt(client_sock, SOL_SOCKET, SO_RCVTIMEO, &client_timeout, sizeof(client_timeout));
- setsockopt(client_sock, SOL_SOCKET, SO_SNDTIMEO, &client_timeout, sizeof(client_timeout));
//
// Send and receive info from server
// Send message
@@ -632,7 +610,7 @@ static char *create_cache_filename(char *name, int rid, char *buffer, int maxlen
}
FILE *fh;
while ((fh = fopen(buffer, "rb")))
- { // Alter file name as long as a file by that name already exists
+ { // Alter file name as long as a file by that name already exists (el cheapo edition)
fclose(fh);
char *c = buffer + rand() % strlen(buffer);
*c = rand() % 26 + 'A';
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-07 00:08:54 +0200