From: NeilBrown <neilb@cse.unsw.edu.au>
Reference-counting the nfsd4 stateowner structs will let us fix a race and
simplify some of the xdr code a bit, and may also help us make the nfsd4
locking a little more fine-grained in the future.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/nfsd/nfs4state.c | 27 ++++++++++++++-------------
25-akpm/include/linux/nfsd/state.h | 16 ++++++++++++++++
2 files changed, 30 insertions(+), 13 deletions(-)
diff -puN fs/nfsd/nfs4state.c~nfsd4-reference-count-stateowners fs/nfsd/nfs4state.c
--- 25/fs/nfsd/nfs4state.c~nfsd4-reference-count-stateowners 2004-09-23 22:06:21.650797200 -0700
+++ 25-akpm/fs/nfsd/nfs4state.c 2004-09-23 22:09:46.582642824 -0700
@@ -833,6 +833,17 @@ release_all_files(void)
}
}
+/* should use a slab cache */
+void
+nfs4_free_stateowner(struct kref *kref)
+{
+ struct nfs4_stateowner *sop =
+ container_of(kref, struct nfs4_stateowner, so_ref);
+ kfree(sop->so_owner.data);
+ kfree(sop);
+ free_sowner++;
+}
+
static inline struct nfs4_stateowner *
alloc_stateowner(struct xdr_netobj *owner)
{
@@ -842,6 +853,7 @@ alloc_stateowner(struct xdr_netobj *owne
if ((sop->so_owner.data = kmalloc(owner->len, GFP_KERNEL))) {
memcpy(sop->so_owner.data, owner->data, owner->len);
sop->so_owner.len = owner->len;
+ kref_init(&sop->so_ref);
return sop;
}
kfree(sop);
@@ -849,17 +861,6 @@ alloc_stateowner(struct xdr_netobj *owne
return NULL;
}
-/* should use a slab cache */
-static void
-free_stateowner(struct nfs4_stateowner *sop) {
- if (sop) {
- kfree(sop->so_owner.data);
- kfree(sop);
- sop = NULL;
- free_sowner++;
- }
-}
-
static struct nfs4_stateowner *
alloc_init_open_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfsd4_open *open) {
struct nfs4_stateowner *sop;
@@ -932,7 +933,7 @@ release_stateowner(struct nfs4_stateowne
{
unhash_stateowner(sop);
list_del(&sop->so_close_lru);
- free_stateowner(sop);
+ nfs4_put_stateowner(sop);
}
static inline void
@@ -1460,7 +1461,7 @@ nfs4_laundromat(void)
dprintk("NFSD: purging unused open stateowner (so_id %d)\n",
sop->so_id);
list_del(&sop->so_close_lru);
- free_stateowner(sop);
+ nfs4_put_stateowner(sop);
}
if (clientid_val < NFSD_LAUNDROMAT_MINTIMEOUT)
clientid_val = NFSD_LAUNDROMAT_MINTIMEOUT;
diff -puN include/linux/nfsd/state.h~nfsd4-reference-count-stateowners include/linux/nfsd/state.h
--- 25/include/linux/nfsd/state.h~nfsd4-reference-count-stateowners 2004-09-23 22:06:21.663795224 -0700
+++ 25-akpm/include/linux/nfsd/state.h 2004-09-23 22:06:21.669794312 -0700
@@ -38,6 +38,7 @@
#define _NFSD4_STATE_H
#include <linux/list.h>
+#include <linux/kref.h>
#include <linux/sunrpc/clnt.h>
#define NFS4_OPAQUE_LIMIT 1024
@@ -168,6 +169,7 @@ struct nfs4_replay {
* reaped by laundramat thread after lease period.
*/
struct nfs4_stateowner {
+ struct kref so_ref;
struct list_head so_idhash; /* hash by so_id */
struct list_head so_strhash; /* hash by op_name */
struct list_head so_perclient; /* nfs4_client->cl_perclient */
@@ -248,4 +250,18 @@ extern void nfs4_lock_state(void);
extern void nfs4_unlock_state(void);
extern int nfs4_in_grace(void);
extern int nfs4_check_open_reclaim(clientid_t *clid);
+extern void nfs4_free_stateowner(struct kref *kref);
+
+static inline void
+nfs4_put_stateowner(struct nfs4_stateowner *so)
+{
+ kref_put(&so->so_ref, nfs4_free_stateowner);
+}
+
+static inline void
+nfs4_get_stateowner(struct nfs4_stateowner *so)
+{
+ kref_get(&so->so_ref);
+}
+
#endif /* NFSD4_STATE_H */
_