From eab7e2e647c348b418e8715ecaca0177e1b473c7 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 27 Mar 2006 01:15:00 -0800
Subject: [PATCH] knfsd: Break the hard linkage from svc_expkey to svc_export
Current svc_expkey holds a pointer to the svc_export structure, so updates to
that structure have to be in-place, which is a wart on the whole cache
infrastruct. So we break that linkage and just do a second lookup.
If this became a performance issue, it would be possible to put a direct link
back in which was only used conditionally. i.e. when an object is replaced
in the cache, we set a flag in the old object. When dereferencing the link
from svc_expkey, if the flag is set, we drop the reference and do a fresh
lookup.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
include/linux/nfsd/export.h | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)
(limited to 'include/linux')
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index 6bad4766d3d9..d52e0b7ad37b 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -67,7 +67,8 @@ struct svc_expkey {
int ek_fsidtype;
u32 ek_fsid[3];
- struct svc_export * ek_export;
+ struct vfsmount * ek_mnt;
+ struct dentry * ek_dentry;
};
#define EX_SECURE(exp) (!((exp)->ex_flags & NFSEXP_INSECURE_PORT))
@@ -114,22 +115,9 @@ static inline void exp_get(struct svc_export *exp)
{
cache_get(&exp->h);
}
-static inline struct svc_export *
+extern struct svc_export *
exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
- struct cache_req *reqp)
-{
- struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);
- if (ek && !IS_ERR(ek)) {
- struct svc_export *exp = ek->ek_export;
- int err;
- exp_get(exp);
- expkey_put(&ek->h, &svc_expkey_cache);
- if ((err = cache_check(&svc_export_cache, &exp->h, reqp)))
- exp = ERR_PTR(err);
- return exp;
- } else
- return ERR_PTR(PTR_ERR(ek));
-}
+ struct cache_req *reqp);
#endif /* __KERNEL__ */
--
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