q3k/linux
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
linux/fs/nfs/nfs4state.c
Trond Myklebust 9512135df1 NFSv4: Fix a potential CLOSE race 
Once the state_owner and lock_owner semaphores get removed, it will be
 possible for other OPEN requests to reopen the same file if they have
 lower sequence ids than our CLOSE call.
 This patch ensures that we recheck the file state once
 nfs_wait_on_sequence() has completed waiting.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-18 14:20:12 -07:00

1004 lines
25 KiB
C
Raw Blame History

/*
* fs/nfs/nfs4state.c
*
* Client-side XDR for NFSv4.
*
* Copyright (c) 2002 The Regents of the University of Michigan.
* All rights reserved.
*
* Kendrick Smith <kmsmith@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Implementation of the NFSv4 state model. For the time being,
* this is minimal, but will be made much more complex in a
* subsequent patch.
*/
#include <linux/config.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#define OPENOWNER_POOL_SIZE 8
const nfs4_stateid zero_stateid;
static DEFINE_SPINLOCK(state_spinlock);
static LIST_HEAD(nfs4_clientid_list);
static void nfs4_recover_state(void *);
void
init_nfsv4_state(struct nfs_server *server)
{
server->nfs4_state = NULL;
INIT_LIST_HEAD(&server->nfs4_siblings);
}
void
destroy_nfsv4_state(struct nfs_server *server)
{
if (server->mnt_path) {
kfree(server->mnt_path);
server->mnt_path = NULL;
}
if (server->nfs4_state) {
nfs4_put_client(server->nfs4_state);
server->nfs4_state = NULL;
}
}
/*
* nfs4_get_client(): returns an empty client structure
* nfs4_put_client(): drops reference to client structure
*
* Since these are allocated/deallocated very rarely, we don't
* bother putting them in a slab cache...
*/
static struct nfs4_client *
nfs4_alloc_client(struct in_addr *addr)
{
struct nfs4_client *clp;
if (nfs_callback_up() < 0)
return NULL;
if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
nfs_callback_down();
return NULL;
}
memset(clp, 0, sizeof(*clp));
memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
init_rwsem(&clp->cl_sem);
INIT_LIST_HEAD(&clp->cl_delegations);
INIT_LIST_HEAD(&clp->cl_state_owners);
INIT_LIST_HEAD(&clp->cl_unused);
spin_lock_init(&clp->cl_lock);
atomic_set(&clp->cl_count, 1);
INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
INIT_LIST_HEAD(&clp->cl_superblocks);
init_waitqueue_head(&clp->cl_waitq);
rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
clp->cl_rpcclient = ERR_PTR(-EINVAL);
clp->cl_boot_time = CURRENT_TIME;
clp->cl_state = 1 << NFS4CLNT_OK;
return clp;
}
static void
nfs4_free_client(struct nfs4_client *clp)
{
struct nfs4_state_owner *sp;
while (!list_empty(&clp->cl_unused)) {
sp = list_entry(clp->cl_unused.next,
struct nfs4_state_owner,
so_list);
list_del(&sp->so_list);
kfree(sp);
}
BUG_ON(!list_empty(&clp->cl_state_owners));
if (clp->cl_cred)
put_rpccred(clp->cl_cred);
nfs_idmap_delete(clp);
if (!IS_ERR(clp->cl_rpcclient))
rpc_shutdown_client(clp->cl_rpcclient);
kfree(clp);
nfs_callback_down();
}
static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
{
struct nfs4_client *clp;
list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
atomic_inc(&clp->cl_count);
return clp;
}
}
return NULL;
}
struct nfs4_client *nfs4_find_client(struct in_addr *addr)
{
struct nfs4_client *clp;
spin_lock(&state_spinlock);
clp = __nfs4_find_client(addr);
spin_unlock(&state_spinlock);
return clp;
}
struct nfs4_client *
nfs4_get_client(struct in_addr *addr)
{
struct nfs4_client *clp, *new = NULL;
spin_lock(&state_spinlock);
for (;;) {
clp = __nfs4_find_client(addr);
if (clp != NULL)
break;
clp = new;
if (clp != NULL) {
list_add(&clp->cl_servers, &nfs4_clientid_list);
new = NULL;
break;
}
spin_unlock(&state_spinlock);
new = nfs4_alloc_client(addr);
spin_lock(&state_spinlock);
if (new == NULL)
break;
}
spin_unlock(&state_spinlock);
if (new)
nfs4_free_client(new);
return clp;
}
void
nfs4_put_client(struct nfs4_client *clp)
{
if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
return;
list_del(&clp->cl_servers);
spin_unlock(&state_spinlock);
BUG_ON(!list_empty(&clp->cl_superblocks));
wake_up_all(&clp->cl_waitq);
rpc_wake_up(&clp->cl_rpcwaitq);
nfs4_kill_renewd(clp);
nfs4_free_client(clp);
}
static int __nfs4_init_client(struct nfs4_client *clp)
{
int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, nfs_callback_tcpport);
if (status == 0)
status = nfs4_proc_setclientid_confirm(clp);
if (status == 0)
nfs4_schedule_state_renewal(clp);
return status;
}
int nfs4_init_client(struct nfs4_client *clp)
{
return nfs4_map_errors(__nfs4_init_client(clp));
}
u32
nfs4_alloc_lockowner_id(struct nfs4_client *clp)
{
return clp->cl_lockowner_id ++;
}
static struct nfs4_state_owner *
nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
{
struct nfs4_state_owner *sp = NULL;
if (!list_empty(&clp->cl_unused)) {
sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
atomic_inc(&sp->so_count);
sp->so_cred = cred;
list_move(&sp->so_list, &clp->cl_state_owners);
clp->cl_nunused--;
}
return sp;
}
static struct nfs4_state_owner *
nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
{
struct nfs4_state_owner *sp, *res = NULL;
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
if (sp->so_cred != cred)
continue;
atomic_inc(&sp->so_count);
/* Move to the head of the list */
list_move(&sp->so_list, &clp->cl_state_owners);
res = sp;
break;
}
return res;
}
/*
* nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
* create a new state_owner.
*
*/
static struct nfs4_state_owner *
nfs4_alloc_state_owner(void)
{
struct nfs4_state_owner *sp;
sp = kzalloc(sizeof(*sp),GFP_KERNEL);
if (!sp)
return NULL;
init_MUTEX(&sp->so_sema);
INIT_LIST_HEAD(&sp->so_states);
INIT_LIST_HEAD(&sp->so_delegations);
rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
sp->so_seqid.sequence = &sp->so_sequence;
spin_lock_init(&sp->so_sequence.lock);
INIT_LIST_HEAD(&sp->so_sequence.list);
atomic_set(&sp->so_count, 1);
return sp;
}
void
nfs4_drop_state_owner(struct nfs4_state_owner *sp)
{
struct nfs4_client *clp = sp->so_client;
spin_lock(&clp->cl_lock);
list_del_init(&sp->so_list);
spin_unlock(&clp->cl_lock);
}
/*
* Note: must be called with clp->cl_sem held in order to prevent races
* with reboot recovery!
*/
struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
{
struct nfs4_client *clp = server->nfs4_state;
struct nfs4_state_owner *sp, *new;
get_rpccred(cred);
new = nfs4_alloc_state_owner();
spin_lock(&clp->cl_lock);
sp = nfs4_find_state_owner(clp, cred);
if (sp == NULL)
sp = nfs4_client_grab_unused(clp, cred);
if (sp == NULL && new != NULL) {
list_add(&new->so_list, &clp->cl_state_owners);
new->so_client = clp;
new->so_id = nfs4_alloc_lockowner_id(clp);
new->so_cred = cred;
sp = new;
new = NULL;
}
spin_unlock(&clp->cl_lock);
if (new)
kfree(new);
if (sp != NULL)
return sp;
put_rpccred(cred);
return NULL;
}
/*
* Must be called with clp->cl_sem held in order to avoid races
* with state recovery...
*/
void nfs4_put_state_owner(struct nfs4_state_owner *sp)
{
struct nfs4_client *clp = sp->so_client;
struct rpc_cred *cred = sp->so_cred;
if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
return;
if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
goto out_free;
if (list_empty(&sp->so_list))
goto out_free;
list_move(&sp->so_list, &clp->cl_unused);
clp->cl_nunused++;
spin_unlock(&clp->cl_lock);
put_rpccred(cred);
cred = NULL;
return;
out_free:
list_del(&sp->so_list);
spin_unlock(&clp->cl_lock);
put_rpccred(cred);
kfree(sp);
}
static struct nfs4_state *
nfs4_alloc_open_state(void)
{
struct nfs4_state *state;
state = kmalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return NULL;
state->state = 0;
state->nreaders = 0;
state->nwriters = 0;
state->flags = 0;
memset(state->stateid.data, 0, sizeof(state->stateid.data));
atomic_set(&state->count, 1);
INIT_LIST_HEAD(&state->lock_states);
init_MUTEX(&state->lock_sema);
spin_lock_init(&state->state_lock);
return state;
}
static struct nfs4_state *
__nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs4_state *state;
mode &= (FMODE_READ|FMODE_WRITE);
list_for_each_entry(state, &nfsi->open_states, inode_states) {
if (state->owner->so_cred != cred)
continue;
if ((mode & FMODE_READ) != 0 && state->nreaders == 0)
continue;
if ((mode & FMODE_WRITE) != 0 && state->nwriters == 0)
continue;
if ((state->state & mode) != mode)
continue;
atomic_inc(&state->count);
if (mode & FMODE_READ)
state->nreaders++;
if (mode & FMODE_WRITE)
state->nwriters++;
return state;
}
return NULL;
}
static struct nfs4_state *
__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs4_state *state;
list_for_each_entry(state, &nfsi->open_states, inode_states) {
/* Is this in the process of being freed? */
if (state->nreaders == 0 && state->nwriters == 0)
continue;
if (state->owner == owner) {
atomic_inc(&state->count);
return state;
}
}
return NULL;
}
struct nfs4_state *
nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
{
struct nfs4_state *state;
spin_lock(&inode->i_lock);
state = __nfs4_find_state(inode, cred, mode);
spin_unlock(&inode->i_lock);
return state;
}
static void
nfs4_free_open_state(struct nfs4_state *state)
{
kfree(state);
}
struct nfs4_state *
nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
{
struct nfs4_state *state, *new;
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&inode->i_lock);
state = __nfs4_find_state_byowner(inode, owner);
spin_unlock(&inode->i_lock);
if (state)
goto out;
new = nfs4_alloc_open_state();
spin_lock(&inode->i_lock);
state = __nfs4_find_state_byowner(inode, owner);
if (state == NULL && new != NULL) {
state = new;
/* Caller *must* be holding owner->so_sem */
/* Note: The reclaim code dictates that we add stateless
* and read-only stateids to the end of the list */
list_add_tail(&state->open_states, &owner->so_states);
state->owner = owner;
atomic_inc(&owner->so_count);
list_add(&state->inode_states, &nfsi->open_states);
state->inode = igrab(inode);
spin_unlock(&inode->i_lock);
} else {
spin_unlock(&inode->i_lock);
if (new)
nfs4_free_open_state(new);
}
out:
return state;
}
/*
* Beware! Caller must be holding exactly one
* reference to clp->cl_sem and owner->so_sema!
*/
void nfs4_put_open_state(struct nfs4_state *state)
{
struct inode *inode = state->inode;
struct nfs4_state_owner *owner = state->owner;
if (!atomic_dec_and_lock(&state->count, &inode->i_lock))
return;
if (!list_empty(&state->inode_states))
list_del(&state->inode_states);
spin_unlock(&inode->i_lock);
list_del(&state->open_states);
iput(inode);
BUG_ON (state->state != 0);
nfs4_free_open_state(state);
nfs4_put_state_owner(owner);
}
/*
* Beware! Caller must be holding no references to clp->cl_sem!
* of owner->so_sema!
*/
void nfs4_close_state(struct nfs4_state *state, mode_t mode)
{
struct inode *inode = state->inode;
struct nfs4_state_owner *owner = state->owner;
struct nfs4_client *clp = owner->so_client;
int newstate;
atomic_inc(&owner->so_count);
down_read(&clp->cl_sem);
down(&owner->so_sema);
/* Protect against nfs4_find_state() */
spin_lock(&inode->i_lock);
if (mode & FMODE_READ)
state->nreaders--;
if (mode & FMODE_WRITE)
state->nwriters--;
if (state->nwriters == 0) {
if (state->nreaders == 0)
list_del_init(&state->inode_states);
/* See reclaim code */
list_move_tail(&state->open_states, &owner->so_states);
}
spin_unlock(&inode->i_lock);
newstate = 0;
if (state->state != 0) {
if (state->nreaders)
newstate |= FMODE_READ;
if (state->nwriters)
newstate |= FMODE_WRITE;
if (state->state == newstate)
goto out;
if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
state->state = newstate;
goto out;
}
if (nfs4_do_close(inode, state, newstate) == 0)
return;
}
out:
nfs4_put_open_state(state);
up(&owner->so_sema);
nfs4_put_state_owner(owner);
up_read(&clp->cl_sem);
}
/*
* Search the state->lock_states for an existing lock_owner
* that is compatible with current->files
*/
static struct nfs4_lock_state *
__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
{
struct nfs4_lock_state *pos;
list_for_each_entry(pos, &state->lock_states, ls_locks) {
if (pos->ls_owner != fl_owner)
continue;
atomic_inc(&pos->ls_count);
return pos;
}
return NULL;
}
/*
* Return a compatible lock_state. If no initialized lock_state structure
* exists, return an uninitialized one.
*
* The caller must be holding state->lock_sema
*/
static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
{
struct nfs4_lock_state *lsp;
struct nfs4_client *clp = state->owner->so_client;
lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
if (lsp == NULL)
return NULL;
lsp->ls_seqid.sequence = &state->owner->so_sequence;
atomic_set(&lsp->ls_count, 1);
lsp->ls_owner = fl_owner;
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;
}
/*
* Return a compatible lock_state. If no initialized lock_state structure
* exists, return an uninitialized one.
*
* The caller must be holding state->lock_sema and clp->cl_sem
*/
static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
{
struct nfs4_lock_state *lsp, *new = NULL;
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)
{
struct nfs4_lock_state *lsp;
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);
}
struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
{
struct rpc_sequence *sequence = counter->sequence;
struct nfs_seqid *new;
new = kmalloc(sizeof(*new), GFP_KERNEL);
if (new != NULL) {
new->sequence = counter;
new->task = NULL;
spin_lock(&sequence->lock);
list_add_tail(&new->list, &sequence->list);
spin_unlock(&sequence->lock);
}
return new;
}
void nfs_free_seqid(struct nfs_seqid *seqid)
{
struct rpc_sequence *sequence = seqid->sequence->sequence;
struct rpc_task *next = NULL;
spin_lock(&sequence->lock);
list_del(&seqid->list);
if (!list_empty(&sequence->list)) {
next = list_entry(sequence->list.next, struct nfs_seqid, list)->task;
if (next)
rpc_wake_up_task(next);
}
spin_unlock(&sequence->lock);
kfree(seqid);
}
/*
* Called with sp->so_sema and clp->cl_sem held.
*
* Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
* failed with a seqid incrementing error -
* see comments nfs_fs.h:seqid_mutating_error()
*/
static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
{
switch (status) {
case 0:
break;
case -NFS4ERR_BAD_SEQID:
case -NFS4ERR_STALE_CLIENTID:
case -NFS4ERR_STALE_STATEID:
case -NFS4ERR_BAD_STATEID:
case -NFS4ERR_BADXDR:
case -NFS4ERR_RESOURCE:
case -NFS4ERR_NOFILEHANDLE:
/* Non-seqid mutating errors */
return;
};
/*
* Note: no locking needed as we are guaranteed to be first
* on the sequence list
*/
seqid->sequence->counter++;
}
void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
{
if (status == -NFS4ERR_BAD_SEQID) {
struct nfs4_state_owner *sp = container_of(seqid->sequence,
struct nfs4_state_owner, so_seqid);
nfs4_drop_state_owner(sp);
}
return nfs_increment_seqid(status, seqid);
}
/*
* Called with ls->lock_sema and clp->cl_sem held.
*
* Increment the seqid if the LOCK/LOCKU succeeded, or
* failed with a seqid incrementing error -
* see comments nfs_fs.h:seqid_mutating_error()
*/
void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
{
return nfs_increment_seqid(status, seqid);
}
int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
{
struct rpc_sequence *sequence = seqid->sequence->sequence;
int status = 0;
spin_lock(&sequence->lock);
if (sequence->list.next != &seqid->list) {
seqid->task = task;
rpc_sleep_on(&sequence->wait, task, NULL, NULL);
status = -EAGAIN;
}
spin_unlock(&sequence->lock);
return status;
}
static int reclaimer(void *);
struct reclaimer_args {
struct nfs4_client *clp;
struct completion complete;
};
/*
* State recovery routine
*/
void
nfs4_recover_state(void *data)
{
struct nfs4_client *clp = (struct nfs4_client *)data;
struct reclaimer_args args = {
.clp = clp,
};
might_sleep();
init_completion(&args.complete);
if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
goto out_failed_clear;
wait_for_completion(&args.complete);
return;
out_failed_clear:
set_bit(NFS4CLNT_OK, &clp->cl_state);
wake_up_all(&clp->cl_waitq);
rpc_wake_up(&clp->cl_rpcwaitq);
}
/*
* Schedule a state recovery attempt
*/
void
nfs4_schedule_state_recovery(struct nfs4_client *clp)
{
if (!clp)
return;
if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
schedule_work(&clp->cl_recoverd);
}
static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
{
struct inode *inode = state->inode;
struct file_lock *fl;
int status = 0;
for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
if (!(fl->fl_flags & FL_POSIX))
continue;
if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
continue;
status = ops->recover_lock(state, fl);
if (status >= 0)
continue;
switch (status) {
default:
printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
__FUNCTION__, status);
case -NFS4ERR_EXPIRED:
case -NFS4ERR_NO_GRACE:
case -NFS4ERR_RECLAIM_BAD:
case -NFS4ERR_RECLAIM_CONFLICT:
/* kill_proc(fl->fl_owner, SIGLOST, 1); */
break;
case -NFS4ERR_STALE_CLIENTID:
goto out_err;
}
}
return 0;
out_err:
return status;
}
static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
{
struct nfs4_state *state;
struct nfs4_lock_state *lock;
int status = 0;
/* Note: we rely on the sp->so_states list being ordered
* so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
* states first.
* This is needed to ensure that the server won't give us any
* read delegations that we have to return if, say, we are
* recovering after a network partition or a reboot from a
* server that doesn't support a grace period.
*/
list_for_each_entry(state, &sp->so_states, open_states) {
if (state->state == 0)
continue;
status = ops->recover_open(sp, state);
if (status >= 0) {
status = nfs4_reclaim_locks(ops, state);
if (status < 0)
goto out_err;
list_for_each_entry(lock, &state->lock_states, ls_locks) {
if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
printk("%s: Lock reclaim failed!\n",
__FUNCTION__);
}
continue;
}
switch (status) {
default:
printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
__FUNCTION__, status);
case -ENOENT:
case -NFS4ERR_RECLAIM_BAD:
case -NFS4ERR_RECLAIM_CONFLICT:
/*
* Open state on this file cannot be recovered
* All we can do is revert to using the zero stateid.
*/
memset(state->stateid.data, 0,
sizeof(state->stateid.data));
/* Mark the file as being 'closed' */
state->state = 0;
break;
case -NFS4ERR_EXPIRED:
case -NFS4ERR_NO_GRACE:
case -NFS4ERR_STALE_CLIENTID:
goto out_err;
}
}
return 0;
out_err:
return status;
}
static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
{
struct nfs4_state_owner *sp;
struct nfs4_state *state;
struct nfs4_lock_state *lock;
/* Reset all sequence ids to zero */
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
sp->so_seqid.counter = 0;
sp->so_seqid.flags = 0;
list_for_each_entry(state, &sp->so_states, open_states) {
list_for_each_entry(lock, &state->lock_states, ls_locks) {
lock->ls_seqid.counter = 0;
lock->ls_seqid.flags = 0;
lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
}
}
}
}
static int reclaimer(void *ptr)
{
struct reclaimer_args *args = (struct reclaimer_args *)ptr;
struct nfs4_client *clp = args->clp;
struct nfs4_state_owner *sp;
struct nfs4_state_recovery_ops *ops;
int status = 0;
daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
allow_signal(SIGKILL);
atomic_inc(&clp->cl_count);
complete(&args->complete);
/* Ensure exclusive access to NFSv4 state */
lock_kernel();
down_write(&clp->cl_sem);
/* Are there any NFS mounts out there? */
if (list_empty(&clp->cl_superblocks))
goto out;
restart_loop:
status = nfs4_proc_renew(clp);
switch (status) {
case 0:
case -NFS4ERR_CB_PATH_DOWN:
goto out;
case -NFS4ERR_STALE_CLIENTID:
case -NFS4ERR_LEASE_MOVED:
ops = &nfs4_reboot_recovery_ops;
break;
default:
ops = &nfs4_network_partition_recovery_ops;
};
nfs4_state_mark_reclaim(clp);
status = __nfs4_init_client(clp);
if (status)
goto out_error;
/* Mark all delegations for reclaim */
nfs_delegation_mark_reclaim(clp);
/* Note: list is protected by exclusive lock on cl->cl_sem */
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
status = nfs4_reclaim_open_state(ops, sp);
if (status < 0) {
if (status == -NFS4ERR_NO_GRACE) {
ops = &nfs4_network_partition_recovery_ops;
status = nfs4_reclaim_open_state(ops, sp);
}
if (status == -NFS4ERR_STALE_CLIENTID)
goto restart_loop;
if (status == -NFS4ERR_EXPIRED)
goto restart_loop;
}
}
nfs_delegation_reap_unclaimed(clp);
out:
set_bit(NFS4CLNT_OK, &clp->cl_state);
up_write(&clp->cl_sem);
unlock_kernel();
wake_up_all(&clp->cl_waitq);
rpc_wake_up(&clp->cl_rpcwaitq);
if (status == -NFS4ERR_CB_PATH_DOWN)
nfs_handle_cb_pathdown(clp);
nfs4_put_client(clp);
return 0;
out_error:
printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
NIPQUAD(clp->cl_addr.s_addr), -status);
goto out;
}
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
Reference in a new issue View git blame Copy permalink