Re: Convert i_next field in struct inode to a LIST
--=-=-=
Matthew Dillon <dillon@apollo.backplane.com> writes:
> :Attached is a simple patch to convert i_next field of struct inode to a
> :LIST.
> :
> :Kindly review and comment/commit.
> :
> :truely
> :dheeraj
> :--=-=-=
>
> I don't think it needs to be a list, there aren't going to be more
> then a couple of entries in each hash chain (if that), and we need
> to keep that KKASSERT() intact as a safety check.
>
> -Matt
> Matthew Dillon
> <dillon@backplane.com>
>
> :...
> :- ipp = INOHASH(ip->i_dev, ip->i_number);
> :- while ((iq = *ipp) != NULL) {
> :- if (ip == iq)
> :- break;
> :- ipp = &iq->i_next;
> :- }
> :- KKASSERT(ip == iq);
> :- *ipp = ip->i_next;
> :- ip->i_next = NULL;
> : ip->i_flag &= ~IN_HASHED;
> :+ LIST_REMOVE(ip, i_hash);
> : }
> : lwkt_reltoken(&ilock);
> : }
Hello again,
So i have changed it back to an SLIST. (patch attached).
Matt, I wonder how to stick the KKASSERT in there with the 'API' of :SLIST.
I can of course just replace the macro SLIST_REMOVE with the actual code
and place a KKASSERT at an appropriate place. Is that what you'd prefer ?
truely
dheeraj
--=-=-=
Content-Disposition: attachment; filename=patch-inode.txt
Content-Description: patch
Index: inode.h
===================================================================
RCS file: /home/dcvs/src/sys/vfs/ufs/inode.h,v
retrieving revision 1.9
diff -u -r1.9 inode.h
--- inode.h 30 Dec 2004 07:01:52 -0000 1.9
+++ inode.h 7 Apr 2005 11:24:18 -0000
@@ -81,7 +81,7 @@
* active, and is put back when the file is no longer being used.
*/
struct inode {
- struct inode *i_next;/* Hash chain */
+ SLIST_ENTRY(inode) i_hash; /* Hash chain */
struct vnode *i_vnode;/* Vnode associated with this inode. */
struct vnode *i_devvp;/* Vnode for block I/O. */
uint32_t i_flag; /* flags, see below */
Index: ufs_ihash.c
===================================================================
RCS file: /home/dcvs/src/sys/vfs/ufs/ufs_ihash.c,v
retrieving revision 1.15
diff -u -r1.15 ufs_ihash.c
--- ufs_ihash.c 20 Jan 2005 18:08:54 -0000 1.15
+++ ufs_ihash.c 8 Apr 2005 09:32:23 -0000
@@ -50,8 +50,11 @@
static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables");
/*
* Structures associated with inode cacheing.
- */
+
static struct inode **ihashtbl;
+ */
+
+static SLIST_HEAD(ihashhead, inode) *ihashtbl;
static u_long ihash; /* size of hash table - 1 */
static struct lwkt_token ufs_ihash_token;
@@ -79,10 +82,15 @@
ufs_ihashlookup(dev_t dev, ino_t inum)
{
struct inode *ip;
+ struct ihashhead *ipp;
lwkt_tokref ilock;
+
lwkt_gettoken(&ilock, &ufs_ihash_token);
- for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
+
+ ipp = INOHASH(dev, inum);
+
+ SLIST_FOREACH(ip, ipp, i_hash) {
if (inum == ip->i_number && dev == ip->i_dev)
break;
}
@@ -108,10 +116,12 @@
lwkt_tokref ilock;
struct inode *ip;
struct vnode *vp;
+ struct ihashhead *ipp;
lwkt_gettoken(&ilock, &ufs_ihash_token);
+ ipp = INOHASH(dev, inum);
loop:
- for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
+ SLIST_FOREACH(ip, ipp, i_hash) {
if (inum != ip->i_number || dev != ip->i_dev)
continue;
vp = ITOV(ip);
@@ -121,7 +131,7 @@
* We must check to see if the inode has been ripped
* out from under us after blocking.
*/
- for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
+ SLIST_FOREACH(ip, ipp, i_hash) {
if (inum == ip->i_number && dev == ip->i_dev)
break;
}
@@ -146,9 +156,11 @@
{
lwkt_tokref ilock;
struct inode *ip;
+ struct ihashhead *ipp;
lwkt_gettoken(&ilock, &ufs_ihash_token);
- for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
+ ipp = INOHASH(dev, inum);
+ SLIST_FOREACH(ip, ipp, i_hash) {
if (inum == ip->i_number && dev == ip->i_dev) {
if (ip->i_vnode) {
printf("conflict with vnode %p", ip->i_vnode);
@@ -169,22 +181,21 @@
int
ufs_ihashins(struct inode *ip)
{
- struct inode **ipp;
struct inode *iq;
lwkt_tokref ilock;
+ struct ihashhead *ipp;
KKASSERT((ip->i_flag & IN_HASHED) == 0);
lwkt_gettoken(&ilock, &ufs_ihash_token);
ipp = INOHASH(ip->i_dev, ip->i_number);
- while ((iq = *ipp) != NULL) {
- if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
+
+ SLIST_FOREACH(iq, ipp, i_hash) {
+ if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
lwkt_reltoken(&ilock);
return(EBUSY);
}
- ipp = &iq->i_next;
}
- ip->i_next = NULL;
- *ipp = ip;
+ SLIST_INSERT_HEAD(ipp, ip, i_hash);
ip->i_flag |= IN_HASHED;
lwkt_reltoken(&ilock);
return(0);
@@ -197,20 +208,14 @@
ufs_ihashrem(struct inode *ip)
{
lwkt_tokref ilock;
- struct inode **ipp;
+ struct ihashhead *ipp;
struct inode *iq;
lwkt_gettoken(&ilock, &ufs_ihash_token);
if (ip->i_flag & IN_HASHED) {
ipp = INOHASH(ip->i_dev, ip->i_number);
- while ((iq = *ipp) != NULL) {
- if (ip == iq)
- break;
- ipp = &iq->i_next;
- }
- KKASSERT(ip == iq);
- *ipp = ip->i_next;
- ip->i_next = NULL;
+ /* KKASSERT ?? */
+ SLIST_REMOVE(ipp, ip, inode, i_hash);
ip->i_flag &= ~IN_HASHED;
}
lwkt_reltoken(&ilock);
--=-=-=
--
"Nature wants us to react, return blow for blow, cheating for cheating, lie for
lie, and then it requires a Divine power not to hit-back, keep control and
remain unattached, and act with prudence."
--=-=-=--
討論串 (同標題文章)
完整討論串 (本文為第 4 之 10 篇)：