Merge branch 'wip-xinfo-fixed' into xseg

[archipelago] / xseg / sys / xsegbd.c

diff --git a/xseg/sys/xsegbd.c b/xseg/sys/xsegbd.c
index 5925f29..5d6e2d5 100644 (file)
--- a/xseg/sys/xsegbd.c
+++ b/xseg/sys/xsegbd.c
@@ -26,7 +26,7 @@ MODULE_DESCRIPTION("xsegbd");
 MODULE_AUTHOR("XSEG");
 MODULE_LICENSE("GPL");
 
-static long sector_size = 200000;
+static long sector_size = 0;
 static long blksize = 512;
 static int major = 0;
 static char name[XSEGBD_VOLUME_NAMELEN] = "xsegbd";
@@ -292,6 +292,7 @@ static struct xseg_peer xseg_peer_xsegdev = {
 int xsegbd_xseg_init(struct xsegbd *dev)
 {
        struct xseg_port *xport;
+       struct xsegdev *xsegdev;
        int r;
 
        if (!dev->name[0])
@@ -325,12 +326,16 @@ int xsegbd_xseg_init(struct xsegbd *dev)
                XSEGLOG("WARNING: unexpected segment type '%s' vs 'xsegdev'",
                         dev->config.type);
 
-       XSEGLOG("creating segment");
-       r = xseg_create(&dev->config);
-       if (r) {
-               XSEGLOG("cannot create segment");
-               goto err3;
+       xsegdev = xsegdev_get(0);
+       if (!xsegdev->segment) {
+               XSEGLOG("creating segment");
+               r = xseg_create(&dev->config);
+               if (r) {
+                       XSEGLOG("cannot create segment");
+                       goto err3;
+               }
        }
+       xsegdev_put(xsegdev);
 
        XSEGLOG("joining segment");
        dev->xseg = xseg_join("xsegdev", "xsegbd");
@@ -375,6 +380,9 @@ err0:
 
 int xsegbd_xseg_quit(struct xsegbd *dev)
 {
+       /* make sure to unmap the segment first */
+       dev->xseg->type.ops.unmap(dev->xseg, dev->xseg->segment_size);
+
        xseg_destroy(dev->xseg);
        dev->xseg = NULL;
        return 0;
@@ -425,6 +433,50 @@ static const struct block_device_operations xsegbd_ops = {
 
 static void xseg_request_fn(struct request_queue *rq);
 
+static loff_t xsegbd_get_size(struct xsegbd *dev)
+{
+       struct xseg_request *xreq;
+       char *name, *data;
+       uint64_t datasize;
+       loff_t size;
+
+       if ((xreq = xseg_get_request(dev->xseg, dev->src_portno))) {
+               datasize = sizeof(loff_t);
+               BUG_ON(xreq->buffersize - dev->namesize < datasize);
+               BUG_ON(xseg_prep_request(xreq, dev->namesize, datasize));
+
+               name = XSEG_TAKE_PTR(xreq->name, dev->xseg->segment);
+               strncpy(name, dev->name, dev->namesize);
+               xreq->size = datasize;
+               xreq->offset = 0;
+
+               xreq->op = X_INFO;
+
+               BUG_ON(xseg_submit(dev->xseg, dev->dst_portno, xreq) == NoSerial);
+
+               xseg_signal(dev->xseg, dev->dst_portno);
+       }
+
+       /* callback_fn doesn't handle X_INFO reqs atm, and more importantly we
+        * cannot use an async operation to learn the disk size. Currently, this
+        * behaves like a busy-wait loop and makes insmod block until a peer
+        * responds to our X_INFO req. This will change when the sysfs interface is
+        * implemented, to handle disk operations.
+        */
+       while (!(xreq = xseg_receive(dev->xseg, dev->src_portno))) ;
+
+       while (!(xreq->state & XS_SERVED)) ;
+
+       data = XSEG_TAKE_PTR(xreq->data, dev->xseg->segment);
+       /* TODO: make sure we use consistent types accross peers */
+       size = *((off_t *) data);
+
+       if (xreq)
+               xseg_put_request(dev->xseg, dev->src_portno, xreq);
+
+       return size;
+}
+
 static int xsegbd_dev_init(struct xsegbd *dev, int id, sector_t size)
 {
        int ret = -ENOMEM;
@@ -484,7 +536,8 @@ static int xsegbd_dev_init(struct xsegbd *dev, int id, sector_t size)
        if (!dev->blk_req_pending)
                goto out_free_pending;
 
-       dev->sectors = size;
+       /* allow a non-zero sector_size parameter to override the disk size */
+       dev->sectors = sector_size ? sector_size : xsegbd_get_size(dev) / 512ULL;
        set_capacity(disk, dev->sectors);
 
        add_disk(disk); /* immediately activates the device */