[PATCH] NFSv4: Clean up nfs4 lock state accounting
Ensure that lock owner structures are not released prematurely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 591ad1d..afe587d 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -360,7 +360,7 @@
atomic_set(&state->count, 1);
INIT_LIST_HEAD(&state->lock_states);
init_MUTEX(&state->lock_sema);
- rwlock_init(&state->state_lock);
+ spin_lock_init(&state->state_lock);
return state;
}
@@ -542,16 +542,6 @@
return NULL;
}
-struct nfs4_lock_state *
-nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
-{
- struct nfs4_lock_state *lsp;
- read_lock(&state->state_lock);
- lsp = __nfs4_find_lock_state(state, fl_owner);
- read_unlock(&state->state_lock);
- return lsp;
-}
-
/*
* Return a compatible lock_state. If no initialized lock_state structure
* exists, return an uninitialized one.
@@ -568,14 +558,13 @@
return NULL;
lsp->ls_flags = 0;
lsp->ls_seqid = 0; /* arbitrary */
- lsp->ls_id = -1;
memset(lsp->ls_stateid.data, 0, sizeof(lsp->ls_stateid.data));
atomic_set(&lsp->ls_count, 1);
lsp->ls_owner = fl_owner;
- INIT_LIST_HEAD(&lsp->ls_locks);
spin_lock(&clp->cl_lock);
lsp->ls_id = nfs4_alloc_lockowner_id(clp);
spin_unlock(&clp->cl_lock);
+ INIT_LIST_HEAD(&lsp->ls_locks);
return lsp;
}
@@ -585,34 +574,103 @@
*
* The caller must be holding state->lock_sema and clp->cl_sem
*/
-struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
+static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
{
- struct nfs4_lock_state * lsp;
+ struct nfs4_lock_state *lsp, *new = NULL;
- lsp = nfs4_find_lock_state(state, owner);
- if (lsp == NULL)
- lsp = nfs4_alloc_lock_state(state, owner);
+ for(;;) {
+ spin_lock(&state->state_lock);
+ lsp = __nfs4_find_lock_state(state, owner);
+ if (lsp != NULL)
+ break;
+ if (new != NULL) {
+ new->ls_state = state;
+ list_add(&new->ls_locks, &state->lock_states);
+ set_bit(LK_STATE_IN_USE, &state->flags);
+ lsp = new;
+ new = NULL;
+ break;
+ }
+ spin_unlock(&state->state_lock);
+ new = nfs4_alloc_lock_state(state, owner);
+ if (new == NULL)
+ return NULL;
+ }
+ spin_unlock(&state->state_lock);
+ kfree(new);
return lsp;
}
/*
+ * Release reference to lock_state, and free it if we see that
+ * it is no longer in use
+ */
+static void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
+{
+ struct nfs4_state *state;
+
+ if (lsp == NULL)
+ return;
+ state = lsp->ls_state;
+ if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
+ return;
+ list_del(&lsp->ls_locks);
+ if (list_empty(&state->lock_states))
+ clear_bit(LK_STATE_IN_USE, &state->flags);
+ spin_unlock(&state->state_lock);
+ kfree(lsp);
+}
+
+static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
+{
+ struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
+
+ dst->fl_u.nfs4_fl.owner = lsp;
+ atomic_inc(&lsp->ls_count);
+}
+
+static void nfs4_fl_release_lock(struct file_lock *fl)
+{
+ nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
+}
+
+static struct file_lock_operations nfs4_fl_lock_ops = {
+ .fl_copy_lock = nfs4_fl_copy_lock,
+ .fl_release_private = nfs4_fl_release_lock,
+};
+
+int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
+{
+ struct nfs4_lock_state *lsp;
+
+ if (fl->fl_ops != NULL)
+ return 0;
+ lsp = nfs4_get_lock_state(state, fl->fl_owner);
+ if (lsp == NULL)
+ return -ENOMEM;
+ fl->fl_u.nfs4_fl.owner = lsp;
+ fl->fl_ops = &nfs4_fl_lock_ops;
+ return 0;
+}
+
+/*
* Byte-range lock aware utility to initialize the stateid of read/write
* requests.
*/
-void
-nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
+void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
{
- if (test_bit(LK_STATE_IN_USE, &state->flags)) {
- struct nfs4_lock_state *lsp;
+ struct nfs4_lock_state *lsp;
- lsp = nfs4_find_lock_state(state, fl_owner);
- if (lsp) {
- memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
- nfs4_put_lock_state(lsp);
- return;
- }
- }
memcpy(dst, &state->stateid, sizeof(*dst));
+ if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
+ return;
+
+ spin_lock(&state->state_lock);
+ lsp = __nfs4_find_lock_state(state, fl_owner);
+ if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
+ memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
+ spin_unlock(&state->state_lock);
+ nfs4_put_lock_state(lsp);
}
/*
@@ -624,84 +682,6 @@
lsp->ls_seqid++;
}
-/*
-* Check to see if the request lock (type FL_UNLK) effects the fl lock.
-*
-* fl and request must have the same posix owner
-*
-* return:
-* 0 -> fl not effected by request
-* 1 -> fl consumed by request
-*/
-
-static int
-nfs4_check_unlock(struct file_lock *fl, struct file_lock *request)
-{
- if (fl->fl_start >= request->fl_start && fl->fl_end <= request->fl_end)
- return 1;
- return 0;
-}
-
-/*
- * Post an initialized lock_state on the state->lock_states list.
- */
-void nfs4_notify_setlk(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp)
-{
- if (!list_empty(&lsp->ls_locks))
- return;
- atomic_inc(&lsp->ls_count);
- write_lock(&state->state_lock);
- list_add(&lsp->ls_locks, &state->lock_states);
- set_bit(LK_STATE_IN_USE, &state->flags);
- write_unlock(&state->state_lock);
-}
-
-/*
- * to decide to 'reap' lock state:
- * 1) search i_flock for file_locks with fl.lock_state = to ls.
- * 2) determine if unlock will consume found lock.
- * if so, reap
- *
- * else, don't reap.
- *
- */
-void
-nfs4_notify_unlck(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp)
-{
- struct inode *inode = state->inode;
- struct file_lock *fl;
-
- for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
- if (!(fl->fl_flags & FL_POSIX))
- continue;
- if (fl->fl_owner != lsp->ls_owner)
- continue;
- /* Exit if we find at least one lock which is not consumed */
- if (nfs4_check_unlock(fl,request) == 0)
- return;
- }
-
- write_lock(&state->state_lock);
- list_del_init(&lsp->ls_locks);
- if (list_empty(&state->lock_states))
- clear_bit(LK_STATE_IN_USE, &state->flags);
- write_unlock(&state->state_lock);
- nfs4_put_lock_state(lsp);
-}
-
-/*
- * Release reference to lock_state, and free it if we see that
- * it is no longer in use
- */
-void
-nfs4_put_lock_state(struct nfs4_lock_state *lsp)
-{
- if (!atomic_dec_and_test(&lsp->ls_count))
- return;
- BUG_ON (!list_empty(&lsp->ls_locks));
- kfree(lsp);
-}
-
/*
* Called with sp->so_sema and clp->cl_sem held.
*