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path: root/fs/nfs/delegation.c
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Diffstat (limited to 'fs/nfs/delegation.c')
-rw-r--r--fs/nfs/delegation.c154
1 files changed, 110 insertions, 44 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 81c5eec3cf3..6390a4b5fee 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -55,7 +55,8 @@ int nfs4_have_delegation(struct inode *inode, fmode_t flags)
flags &= FMODE_READ|FMODE_WRITE;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
- if (delegation != NULL && (delegation->type & flags) == flags) {
+ if (delegation != NULL && (delegation->type & flags) == flags &&
+ !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
nfs_mark_delegation_referenced(delegation);
ret = 1;
}
@@ -70,8 +71,10 @@ static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_
int status = 0;
if (inode->i_flock == NULL)
- goto out;
+ return 0;
+ if (inode->i_flock == NULL)
+ goto out;
/* Protect inode->i_flock using the file locks lock */
lock_flocks();
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
@@ -94,7 +97,9 @@ static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *s
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *ctx;
+ struct nfs4_state_owner *sp;
struct nfs4_state *state;
+ unsigned int seq;
int err;
again:
@@ -109,9 +114,16 @@ again:
continue;
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
+ sp = state->owner;
+ /* Block nfs4_proc_unlck */
+ mutex_lock(&sp->so_delegreturn_mutex);
+ seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
err = nfs4_open_delegation_recall(ctx, state, stateid);
- if (err >= 0)
+ if (!err)
err = nfs_delegation_claim_locks(ctx, state);
+ if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+ err = -EAGAIN;
+ mutex_unlock(&sp->so_delegreturn_mutex);
put_nfs_open_context(ctx);
if (err != 0)
return err;
@@ -182,39 +194,91 @@ static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation
}
static struct nfs_delegation *
+nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
+{
+ struct nfs_delegation *ret = NULL;
+ struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
+
+ if (delegation == NULL)
+ goto out;
+ spin_lock(&delegation->lock);
+ if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
+ ret = delegation;
+ spin_unlock(&delegation->lock);
+out:
+ return ret;
+}
+
+static struct nfs_delegation *
+nfs_start_delegation_return(struct nfs_inode *nfsi)
+{
+ struct nfs_delegation *delegation;
+
+ rcu_read_lock();
+ delegation = nfs_start_delegation_return_locked(nfsi);
+ rcu_read_unlock();
+ return delegation;
+}
+
+static void
+nfs_abort_delegation_return(struct nfs_delegation *delegation,
+ struct nfs_client *clp)
+{
+
+ spin_lock(&delegation->lock);
+ clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
+ set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+ spin_unlock(&delegation->lock);
+ set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
+}
+
+static struct nfs_delegation *
nfs_detach_delegation_locked(struct nfs_inode *nfsi,
- struct nfs_server *server)
+ struct nfs_delegation *delegation,
+ struct nfs_client *clp)
{
- struct nfs_delegation *delegation =
+ struct nfs_delegation *deleg_cur =
rcu_dereference_protected(nfsi->delegation,
- lockdep_is_held(&server->nfs_client->cl_lock));
+ lockdep_is_held(&clp->cl_lock));
- if (delegation == NULL)
- goto nomatch;
+ if (deleg_cur == NULL || delegation != deleg_cur)
+ return NULL;
spin_lock(&delegation->lock);
+ set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
list_del_rcu(&delegation->super_list);
delegation->inode = NULL;
nfsi->delegation_state = 0;
rcu_assign_pointer(nfsi->delegation, NULL);
spin_unlock(&delegation->lock);
return delegation;
-nomatch:
- return NULL;
}
static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
- struct nfs_server *server)
+ struct nfs_delegation *delegation,
+ struct nfs_server *server)
{
struct nfs_client *clp = server->nfs_client;
- struct nfs_delegation *delegation;
spin_lock(&clp->cl_lock);
- delegation = nfs_detach_delegation_locked(nfsi, server);
+ delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
spin_unlock(&clp->cl_lock);
return delegation;
}
+static struct nfs_delegation *
+nfs_inode_detach_delegation(struct inode *inode)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct nfs_delegation *delegation;
+
+ delegation = nfs_start_delegation_return(nfsi);
+ if (delegation == NULL)
+ return NULL;
+ return nfs_detach_delegation(nfsi, delegation, server);
+}
+
/**
* nfs_inode_set_delegation - set up a delegation on an inode
* @inode: inode to which delegation applies
@@ -268,7 +332,10 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
delegation = NULL;
goto out;
}
- freeme = nfs_detach_delegation_locked(nfsi, server);
+ freeme = nfs_detach_delegation_locked(nfsi,
+ old_delegation, clp);
+ if (freeme == NULL)
+ goto out;
}
list_add_rcu(&delegation->super_list, &server->delegations);
nfsi->delegation_state = delegation->type;
@@ -292,19 +359,29 @@ out:
/*
* Basic procedure for returning a delegation to the server
*/
-static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
+static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
+ struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
int err;
- /*
- * Guard against new delegated open/lock/unlock calls and against
- * state recovery
- */
- down_write(&nfsi->rwsem);
- err = nfs_delegation_claim_opens(inode, &delegation->stateid);
- up_write(&nfsi->rwsem);
- if (err)
+ if (delegation == NULL)
+ return 0;
+ do {
+ err = nfs_delegation_claim_opens(inode, &delegation->stateid);
+ if (!issync || err != -EAGAIN)
+ break;
+ /*
+ * Guard against state recovery
+ */
+ err = nfs4_wait_clnt_recover(clp);
+ } while (err == 0);
+
+ if (err) {
+ nfs_abort_delegation_return(delegation, clp);
+ goto out;
+ }
+ if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
goto out;
err = nfs_do_return_delegation(inode, delegation, issync);
@@ -340,13 +417,10 @@ restart:
inode = nfs_delegation_grab_inode(delegation);
if (inode == NULL)
continue;
- delegation = nfs_detach_delegation(NFS_I(inode),
- server);
+ delegation = nfs_start_delegation_return_locked(NFS_I(inode));
rcu_read_unlock();
- if (delegation != NULL)
- err = __nfs_inode_return_delegation(inode,
- delegation, 0);
+ err = nfs_end_delegation_return(inode, delegation, 0);
iput(inode);
if (!err)
goto restart;
@@ -367,15 +441,11 @@ restart:
*/
void nfs_inode_return_delegation_noreclaim(struct inode *inode)
{
- struct nfs_server *server = NFS_SERVER(inode);
- struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
- if (rcu_access_pointer(nfsi->delegation) != NULL) {
- delegation = nfs_detach_delegation(nfsi, server);
- if (delegation != NULL)
- nfs_do_return_delegation(inode, delegation, 0);
- }
+ delegation = nfs_inode_detach_delegation(inode);
+ if (delegation != NULL)
+ nfs_do_return_delegation(inode, delegation, 0);
}
/**
@@ -390,18 +460,14 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode)
*/
int nfs4_inode_return_delegation(struct inode *inode)
{
- struct nfs_server *server = NFS_SERVER(inode);
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int err = 0;
nfs_wb_all(inode);
- if (rcu_access_pointer(nfsi->delegation) != NULL) {
- delegation = nfs_detach_delegation(nfsi, server);
- if (delegation != NULL) {
- err = __nfs_inode_return_delegation(inode, delegation, 1);
- }
- }
+ delegation = nfs_start_delegation_return(nfsi);
+ if (delegation != NULL)
+ err = nfs_end_delegation_return(inode, delegation, 1);
return err;
}
@@ -471,7 +537,7 @@ void nfs_remove_bad_delegation(struct inode *inode)
{
struct nfs_delegation *delegation;
- delegation = nfs_detach_delegation(NFS_I(inode), NFS_SERVER(inode));
+ delegation = nfs_inode_detach_delegation(inode);
if (delegation) {
nfs_inode_find_state_and_recover(inode, &delegation->stateid);
nfs_free_delegation(delegation);
@@ -649,7 +715,7 @@ restart:
if (inode == NULL)
continue;
delegation = nfs_detach_delegation(NFS_I(inode),
- server);
+ delegation, server);
rcu_read_unlock();
if (delegation != NULL)
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 20:14:21 +0000