Implement sync option

[nbd.git] / nbd-server.c

diff --git a/nbd-server.c b/nbd-server.c
index 4426345..58c5cc5 100644 (file)
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -149,6 +149,7 @@ gchar* rungroup=NULL;
 #define F_AUTOREADONLY 8  /**< flag to tell us a file is set to autoreadonly */
 #define F_SPARSE 16      /**< flag to tell us copyronwrite should use a sparse file */
 #define F_SDP 32         /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
+#define F_SYNC 64        /**< Whether to fsync() after a write */
 GHashTable *children;
 char pidfname[256]; /**< name of our PID file */
 char pidftemplate[256]; /**< template to be used for the filename of the PID file */
@@ -550,6 +551,7 @@ GArray* parse_cfile(gchar* f, GError** e) {
                { "copyonwrite", FALSE, PARAM_BOOL,     NULL, F_COPYONWRITE },
                { "sparse_cow", FALSE,  PARAM_BOOL,     NULL, F_SPARSE },
                { "sdp",        FALSE,  PARAM_BOOL,     NULL, F_SDP },
+               { "sync",       FALSE,  PARAM_BOOL,     NULL, F_SYNC },
                { "listenaddr", FALSE,  PARAM_STRING,   NULL, 0 },
        };
        const int lp_size=sizeof(lp)/sizeof(PARAM);
@@ -596,8 +598,9 @@ GArray* parse_cfile(gchar* f, GError** e) {
                lp[5].target=&(s.prerun);
                lp[6].target=&(s.postrun);
                lp[7].target=lp[8].target=lp[9].target=
-                               lp[10].target=lp[11].target=&(s.flags);
-               lp[12].target=&(s.listenaddr);
+                               lp[10].target=lp[11].target=
+                               lp[12].target=&(s.flags);
+               lp[13].target=&(s.listenaddr);
 
                /* After the [generic] group, start parsing exports */
                if(i==1) {
@@ -883,6 +886,7 @@ ssize_t rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) {
        int fhandle;
        off_t foffset;
        size_t maxbytes;
+       ssize_t retval;
 
        if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
                return -1;
@@ -892,7 +896,11 @@ ssize_t rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) {
        DEBUG4("(WRITE to fd %d offset %llu len %u), ", fhandle, foffset, len);
 
        myseek(fhandle, foffset);
-       return write(fhandle, buf, len);
+       retval = write(fhandle, buf, len);
+       if(client->server->flags & F_SYNC) {
+               fsync(fhandle);
+       }
+       return retval;
 }
 
 /**