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NFSv4: Check for the existence of a delegation in nfs4_open_prepare() 

We should not be calling open() on an inode that has a delegation unless
we're doing a reclaim.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2007-07-05 19:02:21 -04:00
parent 3e309914a1
commit aac00a8d0a
1 changed files with 107 additions and 88 deletions
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195
fs/nfs/nfs4proc.c
View File

@ -65,6 +65,7 @@ static int nfs4_async_handle_error(struct rpc_task *, const struct nfs_server *)
static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry);
static int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception);
static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs_client *clp);
static int _nfs4_do_access(struct inode *inode, struct rpc_cred *cred, int openflags);
/* Prevent leaks of NFSv4 errors into userland */
int nfs4_map_errors(int err)
@ -224,6 +225,7 @@ struct nfs4_opendata {
struct path path;
struct dentry *dir;
struct nfs4_state_owner *owner;
struct nfs4_state *state;
struct iattr attrs;
unsigned long timestamp;
unsigned int rpc_done : 1;
@ -296,6 +298,8 @@ static void nfs4_opendata_free(struct kref *kref)
struct nfs4_opendata, kref);
nfs_free_seqid(p->o_arg.seqid);
if (p->state != NULL)
nfs4_put_open_state(p->state);
nfs4_put_state_owner(p->owner);
dput(p->dir);
dput(p->path.dentry);
@ -320,6 +324,15 @@ static int nfs4_wait_for_completion_rpc_task(struct rpc_task *task)
return ret;
}
static int can_open_delegated(struct nfs_delegation *delegation, mode_t open_flags)
{
if ((delegation->type & open_flags) != open_flags)
return 0;
if (delegation->flags & NFS_DELEGATION_NEED_RECLAIM)
return 0;
return 1;
}
static void update_open_stateflags(struct nfs4_state *state, mode_t open_flags)
{
switch (open_flags) {
@ -380,6 +393,65 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_sta
spin_unlock(&state->owner->so_lock);
}
static void nfs4_return_incompatible_delegation(struct inode *inode, mode_t open_flags)
{
struct nfs_delegation *delegation;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (delegation == NULL || (delegation->type & open_flags) == open_flags) {
rcu_read_unlock();
return;
}
rcu_read_unlock();
nfs_inode_return_delegation(inode);
}
static struct nfs4_state *nfs4_try_open_delegated(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_READ|FMODE_WRITE|O_EXCL);
nfs4_stateid stateid;
int ret = -EAGAIN;
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL)
goto out_unlock;
for (;;) {
if (!can_open_delegated(delegation, open_mode))
break;
/* Save the delegation */
memcpy(stateid.data, delegation->stateid.data, sizeof(stateid.data));
rcu_read_unlock();
lock_kernel();
ret = _nfs4_do_access(state->inode, state->owner->so_cred, open_mode);
unlock_kernel();
if (ret != 0)
goto out;
ret = -EAGAIN;
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL)
break;
/* Is the delegation still valid? */
if (memcmp(stateid.data, delegation->stateid.data, sizeof(stateid.data)) != 0)
continue;
rcu_read_unlock();
update_open_stateid(state, NULL, &stateid, open_mode);
goto out_return_state;
}
out_unlock:
rcu_read_unlock();
out:
return ERR_PTR(ret);
out_return_state:
atomic_inc(&state->count);
return state;
}
static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
{
struct inode *inode;
@ -388,6 +460,11 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
nfs4_stateid *deleg_stateid = NULL;
int ret;
if (!data->rpc_done) {
state = nfs4_try_open_delegated(data);
goto out;
}
ret = -EAGAIN;
if (!(data->f_attr.valid & NFS_ATTR_FATTR))
goto err;
@ -423,6 +500,7 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
update_open_stateid(state, &data->o_res.stateid, deleg_stateid, data->o_arg.open_flags);
rcu_read_unlock();
iput(inode);
out:
return state;
err_put_inode:
iput(inode);
@ -690,6 +768,23 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
if (nfs_wait_on_sequence(data->o_arg.seqid, task) != 0)
return;
/*
* Check if we still need to send an OPEN call, or if we can use
* a delegation instead.
*/
if (data->state != NULL) {
struct nfs_delegation *delegation;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
if (delegation != NULL &&
(delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0) {
rcu_read_unlock();
task->tk_action = NULL;
return;
}
rcu_read_unlock();
}
/* Update sequence id. */
data->o_arg.id = sp->so_owner_id.id;
data->o_arg.clientid = sp->so_client->cl_clientid;
@ -906,90 +1001,6 @@ static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *sta
return ret;
}
/*
* Returns a referenced nfs4_state if there is an open delegation on the file
*/
static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred, struct nfs4_state **res)
{
struct nfs_delegation *delegation;
struct nfs_server *server = NFS_SERVER(inode);
struct nfs_client *clp = server->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs4_state_owner *sp = NULL;
struct nfs4_state *state = NULL;
int open_flags = flags & (FMODE_READ|FMODE_WRITE);
int err;
err = -ENOMEM;
if (!(sp = nfs4_get_state_owner(server, cred))) {
dprintk("%s: nfs4_get_state_owner failed!\n", __FUNCTION__);
return err;
}
err = nfs4_recover_expired_lease(server);
if (err != 0)
goto out_put_state_owner;
/* Protect against reboot recovery - NOTE ORDER! */
down_read(&clp->cl_sem);
/* Protect against delegation recall */
down_read(&nfsi->rwsem);
delegation = NFS_I(inode)->delegation;
err = -ENOENT;
if (delegation == NULL || (delegation->type & open_flags) != open_flags)
goto out_err;
err = -ENOMEM;
state = nfs4_get_open_state(inode, sp);
if (state == NULL)
goto out_err;
err = -ENOENT;
if ((state->state & open_flags) == open_flags) {
spin_lock(&inode->i_lock);
update_open_stateflags(state, open_flags);
spin_unlock(&inode->i_lock);
goto out_ok;
} else if (state->state != 0)
goto out_put_open_state;
lock_kernel();
err = _nfs4_do_access(inode, cred, open_flags);
unlock_kernel();
if (err != 0)
goto out_put_open_state;
update_open_stateid(state, NULL, &delegation->stateid, open_flags);
out_ok:
nfs4_put_state_owner(sp);
up_read(&nfsi->rwsem);
up_read(&clp->cl_sem);
*res = state;
return 0;
out_put_open_state:
nfs4_put_open_state(state);
out_err:
up_read(&nfsi->rwsem);
up_read(&clp->cl_sem);
if (err != -EACCES)
nfs_inode_return_delegation(inode);
out_put_state_owner:
nfs4_put_state_owner(sp);
return err;
}
static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred)
{
struct nfs4_exception exception = { };
struct nfs4_state *res = ERR_PTR(-EIO);
int err;
do {
err = _nfs4_open_delegated(inode, flags, cred, &res);
if (err == 0)
break;
res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(inode),
err, &exception));
} while (exception.retry);
return res;
}
/*
* on an EXCLUSIVE create, the server should send back a bitmask with FATTR4-*
* fields corresponding to attributes that were used to store the verifier.
@ -1016,7 +1027,7 @@ static int _nfs4_do_open(struct inode *dir, struct path *path, int flags, struct
struct nfs_server *server = NFS_SERVER(dir);
struct nfs_client *clp = server->nfs_client;
struct nfs4_opendata *opendata;
int status;
int status;
/* Protect against reboot recovery conflicts */
status = -ENOMEM;
@ -1027,12 +1038,17 @@ static int _nfs4_do_open(struct inode *dir, struct path *path, int flags, struct
status = nfs4_recover_expired_lease(server);
if (status != 0)
goto err_put_state_owner;
if (path->dentry->d_inode != NULL)
nfs4_return_incompatible_delegation(path->dentry->d_inode, flags & (FMODE_READ|FMODE_WRITE));
down_read(&clp->cl_sem);
status = -ENOMEM;
opendata = nfs4_opendata_alloc(path, sp, flags, sattr);
if (opendata == NULL)
goto err_release_rwsem;
if (path->dentry->d_inode != NULL)
opendata->state = nfs4_get_open_state(path->dentry->d_inode, sp);
status = _nfs4_proc_open(opendata);
if (status != 0)
goto err_opendata_put;
@ -1099,6 +1115,11 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, int
exception.retry = 1;
continue;
}
if (status == -EAGAIN) {
/* We must have found a delegation */
exception.retry = 1;
continue;
}
res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(dir),
status, &exception));
} while (exception.retry);
@ -1390,9 +1411,7 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st
cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);
if (IS_ERR(cred))
return PTR_ERR(cred);
state = nfs4_open_delegated(dentry->d_inode, openflags, cred);
if (IS_ERR(state))
state = nfs4_do_open(dir, &path, openflags, NULL, cred);
state = nfs4_do_open(dir, &path, openflags, NULL, cred);
put_rpccred(cred);
if (IS_ERR(state)) {
switch (PTR_ERR(state)) {