nfsd: add more granular locking to *_delegations fault injectors

...instead of relying on the client_mutex.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
index d4472cd..2479dba 100644 (file)
--- a/fs/nfsd/fault_inject.c
+++ b/fs/nfsd/fault_inject.c
@@ -152,19 +152,15 @@ static struct nfsd_fault_inject_op inject_ops[] = {
        },
        {
                .file     = "forget_delegations",
-               .get      = nfsd_inject_get,
-               .set_val  = nfsd_inject_set,
-               .set_clnt = nfsd_inject_set_client,
-               .forget   = nfsd_forget_client_delegations,
-               .print    = nfsd_print_client_delegations,
+               .get      = nfsd_inject_print_delegations,
+               .set_val  = nfsd_inject_forget_delegations,
+               .set_clnt = nfsd_inject_forget_client_delegations,
        },
        {
                .file     = "recall_delegations",
-               .get      = nfsd_inject_get,
-               .set_val  = nfsd_inject_set,
-               .set_clnt = nfsd_inject_set_client,
-               .forget   = nfsd_recall_client_delegations,
-               .print    = nfsd_print_client_delegations,
+               .get      = nfsd_inject_print_delegations,
+               .set_val  = nfsd_inject_recall_delegations,
+               .set_clnt = nfsd_inject_recall_client_delegations,
        },
 };
 

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 20bffa8..d18bbb1 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -6102,9 +6102,13 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max,
                                     struct list_head *victims)
 {
        struct nfs4_delegation *dp, *next;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
        u64 count = 0;
 
-       lockdep_assert_held(&state_lock);
+       lockdep_assert_held(&nn->client_lock);
+
+       spin_lock(&state_lock);
        list_for_each_entry_safe(dp, next, &clp->cl_delegations, dl_perclnt) {
                if (victims) {
                        /*
@@ -6116,62 +6120,180 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max,
                        if (dp->dl_time != 0)
                                continue;
 
+                       atomic_inc(&clp->cl_refcount);
                        unhash_delegation_locked(dp);
                        list_add(&dp->dl_recall_lru, victims);
                }
-               if (++count == max)
+               ++count;
+               /*
+                * Despite the fact that these functions deal with
+                * 64-bit integers for "count", we must ensure that
+                * it doesn't blow up the clp->cl_refcount. Throw a
+                * warning if we start to approach INT_MAX here.
+                */
+               WARN_ON_ONCE(count == (INT_MAX / 2));
+               if (count == max)
                        break;
        }
+       spin_unlock(&state_lock);
        return count;
 }
 
-u64 nfsd_forget_client_delegations(struct nfs4_client *clp, u64 max)
+static u64
+nfsd_print_client_delegations(struct nfs4_client *clp)
 {
-       struct nfs4_delegation *dp, *next;
-       LIST_HEAD(victims);
-       u64 count;
+       u64 count = nfsd_find_all_delegations(clp, 0, NULL);
 
-       spin_lock(&state_lock);
-       count = nfsd_find_all_delegations(clp, max, &victims);
-       spin_unlock(&state_lock);
+       nfsd_print_count(clp, count, "delegations");
+       return count;
+}
+
+u64
+nfsd_inject_print_delegations(struct nfsd_fault_inject_op *op)
+{
+       struct nfs4_client *clp;
+       u64 count = 0;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
+
+       if (!nfsd_netns_ready(nn))
+               return 0;
 
-       list_for_each_entry_safe(dp, next, &victims, dl_recall_lru) {
+       spin_lock(&nn->client_lock);
+       list_for_each_entry(clp, &nn->client_lru, cl_lru)
+               count += nfsd_print_client_delegations(clp);
+       spin_unlock(&nn->client_lock);
+
+       return count;
+}
+
+static void
+nfsd_forget_delegations(struct list_head *reaplist)
+{
+       struct nfs4_client *clp;
+       struct nfs4_delegation *dp, *next;
+
+       list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) {
                list_del_init(&dp->dl_recall_lru);
+               clp = dp->dl_stid.sc_client;
                revoke_delegation(dp);
+               put_client(clp);
        }
+}
+
+u64
+nfsd_inject_forget_client_delegations(struct nfsd_fault_inject_op *op,
+                               struct sockaddr_storage *addr, size_t addr_size)
+{
+       u64 count = 0;
+       struct nfs4_client *clp;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
+       LIST_HEAD(reaplist);
+
+       if (!nfsd_netns_ready(nn))
+               return count;
+
+       spin_lock(&nn->client_lock);
+       clp = nfsd_find_client(addr, addr_size);
+       if (clp)
+               count = nfsd_find_all_delegations(clp, 0, &reaplist);
+       spin_unlock(&nn->client_lock);
+
+       nfsd_forget_delegations(&reaplist);
+       return count;
+}
 
+u64
+nfsd_inject_forget_delegations(struct nfsd_fault_inject_op *op, u64 max)
+{
+       u64 count = 0;
+       struct nfs4_client *clp;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
+       LIST_HEAD(reaplist);
+
+       if (!nfsd_netns_ready(nn))
+               return count;
+
+       spin_lock(&nn->client_lock);
+       list_for_each_entry(clp, &nn->client_lru, cl_lru) {
+               count += nfsd_find_all_delegations(clp, max - count, &reaplist);
+               if (max != 0 && count >= max)
+                       break;
+       }
+       spin_unlock(&nn->client_lock);
+       nfsd_forget_delegations(&reaplist);
        return count;
 }
 
-u64 nfsd_recall_client_delegations(struct nfs4_client *clp, u64 max)
+static void
+nfsd_recall_delegations(struct list_head *reaplist)
 {
-       struct nfs4_delegation *dp;
-       LIST_HEAD(victims);
-       u64 count;
+       struct nfs4_client *clp;
+       struct nfs4_delegation *dp, *next;
 
-       spin_lock(&state_lock);
-       count = nfsd_find_all_delegations(clp, max, &victims);
-       while (!list_empty(&victims)) {
-               dp = list_first_entry(&victims, struct nfs4_delegation,
-                                       dl_recall_lru);
+       list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) {
                list_del_init(&dp->dl_recall_lru);
+               clp = dp->dl_stid.sc_client;
+               /*
+                * We skipped all entries that had a zero dl_time before,
+                * so we can now reset the dl_time back to 0. If a delegation
+                * break comes in now, then it won't make any difference since
+                * we're recalling it either way.
+                */
+               spin_lock(&state_lock);
                dp->dl_time = 0;
+               spin_unlock(&state_lock);
                nfsd_break_one_deleg(dp);
+               put_client(clp);
        }
-       spin_unlock(&state_lock);
+}
 
+u64
+nfsd_inject_recall_client_delegations(struct nfsd_fault_inject_op *op,
+                                     struct sockaddr_storage *addr,
+                                     size_t addr_size)
+{
+       u64 count = 0;
+       struct nfs4_client *clp;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
+       LIST_HEAD(reaplist);
+
+       if (!nfsd_netns_ready(nn))
+               return count;
+
+       spin_lock(&nn->client_lock);
+       clp = nfsd_find_client(addr, addr_size);
+       if (clp)
+               count = nfsd_find_all_delegations(clp, 0, &reaplist);
+       spin_unlock(&nn->client_lock);
+
+       nfsd_recall_delegations(&reaplist);
        return count;
 }
 
-u64 nfsd_print_client_delegations(struct nfs4_client *clp, u64 max)
+u64
+nfsd_inject_recall_delegations(struct nfsd_fault_inject_op *op, u64 max)
 {
        u64 count = 0;
+       struct nfs4_client *clp, *next;
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
+       LIST_HEAD(reaplist);
 
-       spin_lock(&state_lock);
-       count = nfsd_find_all_delegations(clp, max, NULL);
-       spin_unlock(&state_lock);
+       if (!nfsd_netns_ready(nn))
+               return count;
 
-       nfsd_print_count(clp, count, "delegations");
+       spin_lock(&nn->client_lock);
+       list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) {
+               count += nfsd_find_all_delegations(clp, max - count, &reaplist);
+               if (max != 0 && ++count >= max)
+                       break;
+       }
+       spin_unlock(&nn->client_lock);
+       nfsd_recall_delegations(&reaplist);
        return count;
 }
 
@@ -6179,7 +6301,8 @@ u64 nfsd_for_n_state(u64 max, u64 (*func)(struct nfs4_client *, u64))
 {
        struct nfs4_client *clp, *next;
        u64 count = 0;
-       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, nfsd_net_id);
+       struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                               nfsd_net_id);
 
        if (!nfsd_netns_ready(nn))
                return 0;

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index faaf6af..0a35e7b 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -493,10 +493,13 @@ u64 nfsd_inject_forget_client_openowners(struct nfsd_fault_inject_op *,
                                         struct sockaddr_storage *, size_t);
 u64 nfsd_inject_forget_openowners(struct nfsd_fault_inject_op *, u64);
 
-u64 nfsd_forget_client_delegations(struct nfs4_client *, u64);
-u64 nfsd_recall_client_delegations(struct nfs4_client *, u64);
-
-u64 nfsd_print_client_delegations(struct nfs4_client *, u64);
+u64 nfsd_inject_print_delegations(struct nfsd_fault_inject_op *);
+u64 nfsd_inject_forget_client_delegations(struct nfsd_fault_inject_op *,
+                                         struct sockaddr_storage *, size_t);
+u64 nfsd_inject_forget_delegations(struct nfsd_fault_inject_op *, u64);
+u64 nfsd_inject_recall_client_delegations(struct nfsd_fault_inject_op *,
+                                         struct sockaddr_storage *, size_t);
+u64 nfsd_inject_recall_delegations(struct nfsd_fault_inject_op *, u64);
 #else /* CONFIG_NFSD_FAULT_INJECTION */
 static inline int nfsd_fault_inject_init(void) { return 0; }
 static inline void nfsd_fault_inject_cleanup(void) {}