Re: [PATCH] d_alloc_anon for 2.4.21-pre6

J.A. Magallon
2003-03-27T22:14:50Z

On 03.27, Christoph Hellwig wrote:
> [$BIGNUM repost since August 2002, still zero feedback]
>
> The rewritten 2.5 nfsd export handling introduce a funcion,
> d_alloc_anon, to get an dentry for a given inode, either taking
> a well-connected one or allocating a new one.
>
> In 2.4 we have the functionality that it does in 2.4 duplicated over
> nfsd and all filesystems having their own fh_to_dentry method, and
> XFS needs even more instances of this for other handle to dentry
> conversations.
>
> This patch adds d_alloc_anon with exactly the same API as in 2.5, but
> the 2.4ish functionality instead to the kernel and switches nfsd, fat
> and reiserfs over to it.
>

The patch I had from time ago in -jam also included this switch to
list_for_each:

diff -uNr -Xdontdiff -p linux-2.4.20-pre4/fs/dcache.c linux/fs/dcache.c
--- linux-2.4.20-pre4/fs/dcache.c Sat Aug 17 14:54:38 2002
+++ linux/fs/dcache.c Tue Aug 20 11:39:48 2002
@@ -247,24 +247,22 @@ struct dentry * dget_locked(struct dentr

struct dentry * d_find_alias(struct inode *inode)
{
- struct list_head *head, *next, *tmp;
- struct dentry *alias;
+ struct dentry *dentry;
+ struct list_head *p;

spin_lock(&dcache_lock);
- head = &inode->i_dentry;
- next = inode->i_dentry.next;
- while (next != head) {
- tmp = next;
- next = tmp->next;
- alias = list_entry(tmp, struct dentry, d_alias);
- if (!list_empty(&alias->d_hash)) {
- __dget_locked(alias);
- spin_unlock(&dcache_lock);
- return alias;
- }
+ list_for_each(p, &inode->i_dentry) {
+ dentry = list_entry(p, struct dentry, d_alias);
+ if (!list_empty(&dentry->d_hash))
+ goto found;
}
spin_unlock(&dcache_lock);
return NULL;
+
+found:
+ __dget_locked(dentry);
+ spin_unlock(&dcache_lock);
+ return dentry;
}

/*

--
J.A. Magallon <jamagallon@able.es> \ Software is like sex:
werewolf.able.es \ It's better when it's free
Mandrake Linux release 9.1 (Bamboo) for i586
Linux 2.4.21-pre5-jam1 (gcc 3.2.2 (Mandrake Linux 9.1 3.2.2-3mdk))