diff options
Diffstat (limited to 'usr/src/uts/common/sys/vnode.h')
| -rw-r--r-- | usr/src/uts/common/sys/vnode.h | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/usr/src/uts/common/sys/vnode.h b/usr/src/uts/common/sys/vnode.h index e4d43cea7f..fbd0e728d9 100644 --- a/usr/src/uts/common/sys/vnode.h +++ b/usr/src/uts/common/sys/vnode.h @@ -22,6 +22,7 @@ /* * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2013, Joyent, Inc. All rights reserved. + * Copyright (c) 2011, 2017 by Delphix. All rights reserved. */ /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ @@ -53,6 +54,7 @@ #include <sys/list.h> #ifdef _KERNEL #include <sys/buf.h> +#include <sys/sdt.h> #endif /* _KERNEL */ #ifdef __cplusplus @@ -1342,10 +1344,32 @@ int vn_vmpss_usepageio(vnode_t *); */ extern uint_t pvn_vmodsort_supported; -#define VN_HOLD(vp) { \ - mutex_enter(&(vp)->v_lock); \ - (vp)->v_count++; \ - mutex_exit(&(vp)->v_lock); \ +/* + * All changes to v_count should be done through VN_HOLD() or VN_RELE(), or + * one of their variants. This makes it possible to ensure proper locking, + * and to guarantee that all modifications are accompanied by a firing of + * the vn-hold or vn-rele SDT DTrace probe. + * + * Example DTrace command for tracing vnode references using these probes: + * + * dtrace -q -n 'sdt:::vn-hold,sdt:::vn-rele + * { + * this->vp = (vnode_t *)arg0; + * printf("%s %s(%p[%s]) %d\n", execname, probename, this->vp, + * this->vp->v_path == NULL ? "NULL" : stringof(this->vp->v_path), + * this->vp->v_count) + * }' + */ +#define VN_HOLD_LOCKED(vp) { \ + ASSERT(mutex_owned(&(vp)->v_lock)); \ + (vp)->v_count++; \ + DTRACE_PROBE1(vn__hold, vnode_t *, vp); \ +} + +#define VN_HOLD(vp) { \ + mutex_enter(&(vp)->v_lock); \ + VN_HOLD_LOCKED(vp); \ + mutex_exit(&(vp)->v_lock); \ } #define VN_RELE(vp) { \ @@ -1356,6 +1380,13 @@ extern uint_t pvn_vmodsort_supported; vn_rele_async(vp, taskq); \ } +#define VN_RELE_LOCKED(vp) { \ + ASSERT(mutex_owned(&(vp)->v_lock)); \ + ASSERT((vp)->v_count >= 1); \ + (vp)->v_count--; \ + DTRACE_PROBE1(vn__rele, vnode_t *, vp); \ +} + #define VN_SET_VFS_TYPE_DEV(vp, vfsp, type, dev) { \ (vp)->v_vfsp = (vfsp); \ (vp)->v_type = (type); \ |