On Thu, Jul 24, 2008 at 08:55:48AM +1000, Dave Chinner wrote:
> On Wed, Jul 23, 2008 at 09:49:50PM +0200, Christoph Hellwig wrote:
> > Now that all direct calls to VN_HOLD/VN_RELE are gone we can implement
> > IHOLD/IRELE directly.
> >
> > For the IHOLD case also replace igrab with a direct increment of i_count
> > because we are guaranteed to already have a live and referenced inode
> > by the VFS. Also remove the vn_hold statistic because it's been rather
> > meaningless for some time with most references done by other callers.
>
> Seeing as you are changing from an igrab() to a straight
> atomic_inc(), can you put an:
>
> ASSERT(atomic_read(&VFS_I(ip)->i_count) > 0)
>
> into the IHOLD macro so we catch screwups in reference counting as
> quickly as possible?
Makes sense, updated patch below. (Half-way through xfsqa with a debug
kernel so far)
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ksyms.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ksyms.c 2008-07-24
07:32:03.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ksyms.c 2008-07-24 07:32:26.000000000
+0200
@@ -179,7 +179,6 @@ EXPORT_SYMBOL(uuid_getnodeuniq);
EXPORT_SYMBOL(uuid_hash64);
EXPORT_SYMBOL(uuid_is_nil);
EXPORT_SYMBOL(uuid_table_remove);
-EXPORT_SYMBOL(vn_hold);
#if defined(CONFIG_XFS_POSIX_ACL)
EXPORT_SYMBOL(xfs_acl_vtoacl);
Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_vnode.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_vnode.c 2008-07-24
07:32:10.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_vnode.c 2008-07-24 07:32:26.000000000
+0200
@@ -82,24 +82,6 @@ vn_ioerror(
xfs_do_force_shutdown(ip->i_mount, SHUTDOWN_DEVICE_REQ, f, l);
}
-
-/*
- * Add a reference to a referenced vnode.
- */
-bhv_vnode_t *
-vn_hold(
- bhv_vnode_t *vp)
-{
- struct inode *inode;
-
- XFS_STATS_INC(vn_hold);
-
- inode = igrab(vp);
- ASSERT(inode);
-
- return vp;
-}
-
#ifdef XFS_INODE_TRACE
/*
Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_vnode.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_vnode.h 2008-07-24
07:32:10.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_vnode.h 2008-07-24 07:32:32.000000000
+0200
@@ -69,22 +69,18 @@ static inline int vn_count(bhv_vnode_t *
return atomic_read(&vp->i_count);
}
-/*
- * Vnode reference counting functions (and macros for compatibility).
- */
-extern bhv_vnode_t *vn_hold(bhv_vnode_t *);
-
-#if defined(XFS_INODE_TRACE)
-#define VN_HOLD(vp) \
- ((void)vn_hold(vp), \
- xfs_itrace_hold(XFS_I(vp), __FILE__, __LINE__, (inst_t
*)__return_address))
-#define VN_RELE(vp) \
- (xfs_itrace_rele(XFS_I(vp), __FILE__, __LINE__, (inst_t
*)__return_address), \
- iput(vp))
-#else
-#define VN_HOLD(vp) ((void)vn_hold(vp))
-#define VN_RELE(vp) (iput(vp))
-#endif
+#define IHOLD(ip) \
+do { \
+ ASSERT(atomic_read(&VFS_I(ip)->i_count) > 0) ; \
+ atomic_inc(&(VFS_I(ip)->i_count)); \
+ xfs_itrace_hold((ip), __FILE__, __LINE__, (inst_t *)__return_address); \
+} while (0)
+
+#define IRELE(ip) \
+do { \
+ xfs_itrace_rele((ip), __FILE__, __LINE__, (inst_t *)__return_address); \
+ iput(VFS_I(ip)); \
+} while (0)
static inline bhv_vnode_t *vn_grab(bhv_vnode_t *vp)
{
Index: linux-2.6-xfs/fs/xfs/xfs_utils.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_utils.h 2008-07-24 07:32:03.000000000
+0200
+++ linux-2.6-xfs/fs/xfs/xfs_utils.h 2008-07-24 07:32:26.000000000 +0200
@@ -18,9 +18,6 @@
#ifndef __XFS_UTILS_H__
#define __XFS_UTILS_H__
-#define IRELE(ip) VN_RELE(VFS_I(ip))
-#define IHOLD(ip) VN_HOLD(VFS_I(ip))
-
extern int xfs_truncate_file(xfs_mount_t *, xfs_inode_t *);
extern int xfs_dir_ialloc(xfs_trans_t **, xfs_inode_t *, mode_t, xfs_nlink_t,
xfs_dev_t, cred_t *, prid_t, int,
|