kernel: devfs: Add callback to request block size

Add bsize() callback within the bdevsw structure. This returns the
number of blocks a block device supports at maximum. This result is *not*
in bytes.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/sys/fs/devfs.c b/sys/fs/devfs.c
index 15a2864..1dfc10d 100644
--- a/sys/fs/devfs.c
+++ b/sys/fs/devfs.c
@@ -137,6 +137,8 @@ devfs_getattr(struct vop_getattr_args *args)
     struct vnode *vp;
     struct vattr *attr;
     struct devfs_node *dnp;
+    struct bdevsw *bdev;
+    size_t size = 0;
 
     vp = args->vp;
     if ((dnp = vp->data) == NULL) {
@@ -146,6 +148,13 @@ devfs_getattr(struct vop_getattr_args *args)
         return -EIO;
     }
 
+    if (dnp->is_block) {
+        bdev = dev_get(dnp->major, dnp->dev);
+        if (bdev->bsize != NULL) {
+            size = bdev->bsize(dnp->dev);
+        }
+    }
+
     /*
      * Set stat attributes from device node structure
      * found within vnode data.
@@ -154,7 +163,7 @@ devfs_getattr(struct vop_getattr_args *args)
      *      size is hardwired to 0.
      */
     attr->mode = dnp->mode;
-    attr->size = 0;
+    attr->size = size;
     return 0;
 }