kernel - Remove the last MP locks from tmpfs (2).

* The tmpfs interlock is the per-mount token now, not the MP lock

Reported-by: Venkatesh Srinivas <me@endeavour.zapto.org>

diff --git a/sys/vfs/tmpfs/tmpfs_vnops.c b/sys/vfs/tmpfs/tmpfs_vnops.c
index eec0f34..39a44cf 100644 (file)
--- a/sys/vfs/tmpfs/tmpfs_vnops.c
+++ b/sys/vfs/tmpfs/tmpfs_vnops.c
@@ -1559,17 +1559,22 @@ filt_tmpfsread(struct knote *kn, long hint)
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);
                return(1);
        }
+
+       /*
+        * Interlock against MP races when performing this function.
+        */
+       lwkt_gettoken(&vp->v_mount->mnt_token);
        off = node->tn_size - kn->kn_fp->f_offset;
        kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
-       if (kn->kn_sfflags & NOTE_OLDAPI)
+       if (kn->kn_sfflags & NOTE_OLDAPI) {
+               lwkt_reltoken(&vp->v_mount->mnt_token);
                return(1);
+       }
 
-       /*
-        * Handle possible MP race interlock on filter check/write
-        */
        if (kn->kn_data == 0) {
                kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
        }
+       lwkt_reltoken(&vp->v_mount->mnt_token);
        return (kn->kn_data != 0);
 }