[src/trunk]: src/lib/libperfuse Correctly pass the advlock owner id from kern...

[manu <manu%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/562522b422fc
branches:  trunk
changeset: 771242:562522b422fc
user:      manu <manu%NetBSD.org@localhost>
date:      Wed Nov 16 04:52:40 2011 +0000

description:
Correctly pass the advlock owner id from kernel to filesystem, instead of
using process PID.

Allow the usage of the read filehandle for advlock, in order to support
shared locks on read-only files

diffstat:

 lib/libperfuse/ops.c |  25 +++++++++++++++++++------
 1 files changed, 19 insertions(+), 6 deletions(-)

diffs (66 lines):

diff -r 92bb833e9236 -r 562522b422fc lib/libperfuse/ops.c
--- a/lib/libperfuse/ops.c      Wed Nov 16 01:45:10 2011 +0000
+++ b/lib/libperfuse/ops.c      Wed Nov 16 04:52:40 2011 +0000
@@ -1,4 +1,4 @@
-/*  $NetBSD: ops.c,v 1.44 2011/11/10 16:21:09 manu Exp $ */
+/*  $NetBSD: ops.c,v 1.45 2011/11/16 04:52:40 manu Exp $ */
 
 /*-
  *  Copyright (c) 2010-2011 Emmanuel Dreyfus. All rights reserved.
@@ -2825,8 +2825,6 @@
        return 0;
 }
 
-/* id is unused */
-/* ARGSUSED2 */
 int
 perfuse_node_advlock(pu, opc, id, op, fl, flags)
        struct puffs_usermount *pu;
@@ -2839,6 +2837,7 @@
        struct perfuse_state *ps;
        int fop;
        perfuse_msg_t *pm;
+       uint64_t fh;
        struct fuse_lk_in *fli;
        struct fuse_out_header *foh;
        struct fuse_lk_out *flo;
@@ -2846,6 +2845,20 @@
        size_t len;
        int error;
        
+       /*
+        * Make sure we do have a filehandle, as the FUSE filesystem
+        * expect one. E.g.: if we provide none, GlusterFS logs an error
+        * "0-glusterfs-fuse: xl is NULL"
+        *
+        * We need the read file handle if the file is open read only,
+        * in order to support shared locks on read-only files.
+        * NB: The kernel always sends advlock for read-only
+        * files at exit time when the process used lock, see
+        * sys_exit -> exit1 -> fd_free -> fd_close -> VOP_ADVLOCK
+        */
+       if ((fh = perfuse_get_fh(opc, FREAD)) == FUSE_UNKNOWN_FH)
+               return EBADF;
+
        ps = puffs_getspecific(pu);
 
        if (op == F_GETLK)
@@ -2862,15 +2875,15 @@
         */
        pm = ps->ps_new_msg(pu, opc, fop, sizeof(*fli), NULL);
        fli = GET_INPAYLOAD(ps, pm, fuse_lk_in);
-       fli->fh = perfuse_get_fh(opc, FWRITE);
-       fli->owner = fl->l_pid;
+       fli->fh = fh;
+       fli->owner = (uint64_t)(vaddr_t)id;
        fli->lk.start = fl->l_start;
        fli->lk.end = fl->l_start + fl->l_len;
        fli->lk.type = fl->l_type;
        fli->lk.pid = fl->l_pid;
        fli->lk_flags = (flags & F_FLOCK) ? FUSE_LK_FLOCK : 0;
 
-       owner = fl->l_pid;
+       owner = (uint64_t)(vaddr_t)id;
 
 #ifdef PERFUSE_DEBUG
        if (perfuse_diagflags & PDF_FH)