[PATCH] Allow softraid crypto to work with write-protected keys

[bytevolcano]

Softraid currently opens the key disk as read + write. This isn't
necessary when just *reading* from the key disk.

This patch allows for softraid crypto to mount volumes with
write-protected keydisks (eg. Kanguru Flash Blu:
https://www.kanguru.com/storage-accessories/flash-blu30.shtml).

Also tested volume creation with the Flash Blu write-protect switch off;
still works as usual.


Index: sys/dev/softraid_crypto.c
===================================================================
RCS file: /cvs/src/sys/dev/softraid_crypto.c,v
retrieving revision 1.126
diff -u -p -r1.126 softraid_crypto.c
--- sys/dev/softraid_crypto.c   12 Apr 2016 16:26:54 -0000
1.126 +++ sys/dev/softraid_crypto.c     17 May 2016 04:18:52 -0000
@@ -797,7 +797,7 @@ sr_crypto_read_key_disk(struct sr_discip
                sr_error(sc, "cannot open key disk %s", devname);
                goto done;
        }
-       if (VOP_OPEN(vn, FREAD | FWRITE, NOCRED, curproc)) {
+       if (VOP_OPEN(vn, FREAD, NOCRED, curproc)) {
                DNPRINTF(SR_D_META,"%s: sr_crypto_read_key_disk cannot
" "open %s\n", DEVNAME(sc), devname);
                vput(vn);
@@ -811,7 +811,7 @@ sr_crypto_read_key_disk(struct sr_discip
            NOCRED, curproc)) {
                DNPRINTF(SR_D_META, "%s: sr_crypto_read_key_disk ioctl
" "failed\n", DEVNAME(sc));
-               VOP_CLOSE(vn, FREAD | FWRITE, NOCRED, curproc);
+               VOP_CLOSE(vn, FREAD, NOCRED, curproc);
                vput(vn);
                goto done;
        }