NFS Client Bugfixes for Linux 5.4-rc6

Stable bugfixes:
 - Fix an RCU lock leak in nfs4_refresh_delegation_stateid()
 
 Other fixes:
 - The TCP back channel mustn't disappear while requests are outstanding
 - The RDMA back channel mustn't disappear while requests are outstanding
 - Destroy the back channel when we destroy the host transport
 - Don't allow a cached open with a revoked delegation
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Merge tag 'nfs-for-5.4-3' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client bugfixes from Anna Schumaker:
 "This contains two delegation fixes (with the RCU lock leak fix marked
  for stable), and three patches to fix destroying the the sunrpc back
  channel.

  Stable bugfixes:

   - Fix an RCU lock leak in nfs4_refresh_delegation_stateid()

  Other fixes:

   - The TCP back channel mustn't disappear while requests are
     outstanding

   - The RDMA back channel mustn't disappear while requests are
     outstanding

   - Destroy the back channel when we destroy the host transport

   - Don't allow a cached open with a revoked delegation"

* tag 'nfs-for-5.4-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFS: Fix an RCU lock leak in nfs4_refresh_delegation_stateid()
  NFSv4: Don't allow a cached open with a revoked delegation
  SUNRPC: Destroy the back channel when we destroy the host transport
  SUNRPC: The RDMA back channel mustn't disappear while requests are outstanding
  SUNRPC: The TCP back channel mustn't disappear while requests are outstanding
This commit is contained in:
Linus Torvalds 2019-11-01 17:37:44 -07:00
commit 372bf6c1c8
7 changed files with 30 additions and 9 deletions

View File

@ -53,6 +53,16 @@ nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
return false;
}
struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
{
struct nfs_delegation *delegation;
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (nfs4_is_valid_delegation(delegation, 0))
return delegation;
return NULL;
}
static int
nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
{
@ -1181,7 +1191,7 @@ bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
if (delegation != NULL &&
nfs4_stateid_match_other(dst, &delegation->stateid)) {
dst->seqid = delegation->stateid.seqid;
return ret;
ret = true;
}
rcu_read_unlock();
out:

View File

@ -68,6 +68,7 @@ int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state,
bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, const struct cred **cred);
bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode);
struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode);
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
int nfs4_have_delegation(struct inode *inode, fmode_t flags);
int nfs4_check_delegation(struct inode *inode, fmode_t flags);

View File

@ -1440,8 +1440,6 @@ static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode,
return 0;
if ((delegation->type & fmode) != fmode)
return 0;
if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
return 0;
switch (claim) {
case NFS4_OPEN_CLAIM_NULL:
case NFS4_OPEN_CLAIM_FH:
@ -1810,7 +1808,6 @@ static void nfs4_return_incompatible_delegation(struct inode *inode, fmode_t fmo
static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
{
struct nfs4_state *state = opendata->state;
struct nfs_inode *nfsi = NFS_I(state->inode);
struct nfs_delegation *delegation;
int open_mode = opendata->o_arg.open_flags;
fmode_t fmode = opendata->o_arg.fmode;
@ -1827,7 +1824,7 @@ static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
}
spin_unlock(&state->owner->so_lock);
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
delegation = nfs4_get_valid_delegation(state->inode);
if (!can_open_delegated(delegation, fmode, claim)) {
rcu_read_unlock();
break;
@ -2371,7 +2368,7 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
data->o_arg.open_flags, claim))
goto out_no_action;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
delegation = nfs4_get_valid_delegation(data->state->inode);
if (can_open_delegated(delegation, data->o_arg.fmode, claim))
goto unlock_no_action;
rcu_read_unlock();

View File

@ -64,6 +64,11 @@ static inline int xprt_setup_backchannel(struct rpc_xprt *xprt,
return 0;
}
static inline void xprt_destroy_backchannel(struct rpc_xprt *xprt,
unsigned int max_reqs)
{
}
static inline bool svc_is_backchannel(const struct svc_rqst *rqstp)
{
return false;

View File

@ -220,7 +220,7 @@ void xprt_destroy_bc(struct rpc_xprt *xprt, unsigned int max_reqs)
goto out;
spin_lock_bh(&xprt->bc_pa_lock);
xprt->bc_alloc_max -= max_reqs;
xprt->bc_alloc_max -= min(max_reqs, xprt->bc_alloc_max);
list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
dprintk("RPC: req=%p\n", req);
list_del(&req->rq_bc_pa_list);
@ -307,8 +307,8 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
*/
dprintk("RPC: Last session removed req=%p\n", req);
xprt_free_allocation(req);
return;
}
xprt_put(xprt);
}
/*
@ -339,7 +339,7 @@ struct rpc_rqst *xprt_lookup_bc_request(struct rpc_xprt *xprt, __be32 xid)
spin_unlock(&xprt->bc_pa_lock);
if (new) {
if (req != new)
xprt_free_bc_rqst(new);
xprt_free_allocation(new);
break;
} else if (req)
break;
@ -368,6 +368,7 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
dprintk("RPC: add callback request to list\n");
xprt_get(xprt);
spin_lock(&bc_serv->sv_cb_lock);
list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
wake_up(&bc_serv->sv_cb_waitq);

View File

@ -1942,6 +1942,11 @@ static void xprt_destroy_cb(struct work_struct *work)
rpc_destroy_wait_queue(&xprt->sending);
rpc_destroy_wait_queue(&xprt->backlog);
kfree(xprt->servername);
/*
* Destroy any existing back channel
*/
xprt_destroy_backchannel(xprt, UINT_MAX);
/*
* Tear down transport state and free the rpc_xprt
*/

View File

@ -163,6 +163,7 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
spin_lock(&xprt->bc_pa_lock);
list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
spin_unlock(&xprt->bc_pa_lock);
xprt_put(xprt);
}
static struct rpc_rqst *rpcrdma_bc_rqst_get(struct rpcrdma_xprt *r_xprt)
@ -259,6 +260,7 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
/* Queue rqst for ULP's callback service */
bc_serv = xprt->bc_serv;
xprt_get(xprt);
spin_lock(&bc_serv->sv_cb_lock);
list_add(&rqst->rq_bc_list, &bc_serv->sv_cb_list);
spin_unlock(&bc_serv->sv_cb_lock);