android_kernel_motorola_sm6225/fs/nfs/nfs4state.c
David Howells 54ceac4515 NFS: Share NFS superblocks per-protocol per-server per-FSID
The attached patch makes NFS share superblocks between mounts from the same
server and FSID over the same protocol.

It does this by creating each superblock with a false root and returning the
real root dentry in the vfsmount presented by get_sb(). The root dentry set
starts off as an anonymous dentry if we don't already have the dentry for its
inode, otherwise it simply returns the dentry we already have.

We may thus end up with several trees of dentries in the superblock, and if at
some later point one of anonymous tree roots is discovered by normal filesystem
activity to be located in another tree within the superblock, the anonymous
root is named and materialises attached to the second tree at the appropriate
point.

Why do it this way? Why not pass an extra argument to the mount() syscall to
indicate the subpath and then pathwalk from the server root to the desired
directory? You can't guarantee this will work for two reasons:

 (1) The root and intervening nodes may not be accessible to the client.

     With NFS2 and NFS3, for instance, mountd is called on the server to get
     the filehandle for the tip of a path. mountd won't give us handles for
     anything we don't have permission to access, and so we can't set up NFS
     inodes for such nodes, and so can't easily set up dentries (we'd have to
     have ghost inodes or something).

     With this patch we don't actually create dentries until we get handles
     from the server that we can use to set up their inodes, and we don't
     actually bind them into the tree until we know for sure where they go.

 (2) Inaccessible symbolic links.

     If we're asked to mount two exports from the server, eg:

	mount warthog:/warthog/aaa/xxx /mmm
	mount warthog:/warthog/bbb/yyy /nnn

     We may not be able to access anything nearer the root than xxx and yyy,
     but we may find out later that /mmm/www/yyy, say, is actually the same
     directory as the one mounted on /nnn. What we might then find out, for
     example, is that /warthog/bbb was actually a symbolic link to
     /warthog/aaa/xxx/www, but we can't actually determine that by talking to
     the server until /warthog is made available by NFS.

     This would lead to having constructed an errneous dentry tree which we
     can't easily fix. We can end up with a dentry marked as a directory when
     it should actually be a symlink, or we could end up with an apparently
     hardlinked directory.

     With this patch we need not make assumptions about the type of a dentry
     for which we can't retrieve information, nor need we assume we know its
     place in the grand scheme of things until we actually see that place.

This patch reduces the possibility of aliasing in the inode and page caches for
inodes that may be accessed by more than one NFS export. It also reduces the
number of superblocks required for NFS where there are many NFS exports being
used from a server (home directory server + autofs for example).

This in turn makes it simpler to do local caching of network filesystems, as it
can then be guaranteed that there won't be links from multiple inodes in
separate superblocks to the same cache file.

Obviously, cache aliasing between different levels of NFS protocol could still
be a problem, but at least that gives us another key to use when indexing the
cache.

This patch makes the following changes:

 (1) The server record construction/destruction has been abstracted out into
     its own set of functions to make things easier to get right.  These have
     been moved into fs/nfs/client.c.

     All the code in fs/nfs/client.c has to do with the management of
     connections to servers, and doesn't touch superblocks in any way; the
     remaining code in fs/nfs/super.c has to do with VFS superblock management.

 (2) The sequence of events undertaken by NFS mount is now reordered:

     (a) A volume representation (struct nfs_server) is allocated.

     (b) A server representation (struct nfs_client) is acquired.  This may be
     	 allocated or shared, and is keyed on server address, port and NFS
     	 version.

     (c) If allocated, the client representation is initialised.  The state
     	 member variable of nfs_client is used to prevent a race during
     	 initialisation from two mounts.

     (d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
     	 the root filehandle for the mount (fs/nfs/getroot.c).  For NFS2/3 we
     	 are given the root FH in advance.

     (e) The volume FSID is probed for on the root FH.

     (f) The volume representation is initialised from the FSINFO record
     	 retrieved on the root FH.

     (g) sget() is called to acquire a superblock.  This may be allocated or
     	 shared, keyed on client pointer and FSID.

     (h) If allocated, the superblock is initialised.

     (i) If the superblock is shared, then the new nfs_server record is
     	 discarded.

     (j) The root dentry for this mount is looked up from the root FH.

     (k) The root dentry for this mount is assigned to the vfsmount.

 (3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
     returns; this function now attaches disconnected trees from alternate
     roots that happen to be discovered attached to a directory being read (in
     the same way nfs_lookup() is made to do for lookup ops).

     The new d_materialise_unique() function is now used to do this, thus
     permitting the whole thing to be done under one set of locks, and thus
     avoiding any race between mount and lookup operations on the same
     directory.

 (4) The client management code uses a new debug facility: NFSDBG_CLIENT which
     is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.

 (5) Clone mounts are now called xdev mounts.

 (6) Use the dentry passed to the statfs() op as the handle for retrieving fs
     statistics rather than the root dentry of the superblock (which is now a
     dummy).

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:37 -04:00

853 lines
22 KiB
C

/*
* 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/slab.h>
#include <linux/smp_lock.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#define OPENOWNER_POOL_SIZE 8
const nfs4_stateid zero_stateid;
static LIST_HEAD(nfs4_clientid_list);
static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
{
int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
nfs_callback_tcpport, cred);
if (status == 0)
status = nfs4_proc_setclientid_confirm(clp, cred);
if (status == 0)
nfs4_schedule_state_renewal(clp);
return status;
}
u32
nfs4_alloc_lockowner_id(struct nfs_client *clp)
{
return clp->cl_lockowner_id ++;
}
static struct nfs4_state_owner *
nfs4_client_grab_unused(struct nfs_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;
}
struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
{
struct nfs4_state_owner *sp;
struct rpc_cred *cred = NULL;
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
if (list_empty(&sp->so_states))
continue;
cred = get_rpccred(sp->so_cred);
break;
}
return cred;
}
struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
{
struct nfs4_state_owner *sp;
if (!list_empty(&clp->cl_state_owners)) {
sp = list_entry(clp->cl_state_owners.next,
struct nfs4_state_owner, so_list);
return get_rpccred(sp->so_cred);
}
return NULL;
}
static struct nfs4_state_owner *
nfs4_find_state_owner(struct nfs_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;
spin_lock_init(&sp->so_lock);
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 nfs_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 nfs_client *clp = server->nfs_client;
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);
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 nfs_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 = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return NULL;
atomic_set(&state->count, 1);
INIT_LIST_HEAD(&state->lock_states);
spin_lock_init(&state->state_lock);
return state;
}
void
nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
{
if (state->state == mode)
return;
/* NB! List reordering - see the reclaim code for why. */
if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
if (mode & FMODE_WRITE)
list_move(&state->open_states, &state->owner->so_states);
else
list_move_tail(&state->open_states, &state->owner->so_states);
}
if (mode == 0)
list_del_init(&state->inode_states);
state->state = mode;
}
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->state == 0)
continue;
if (state->owner == owner) {
atomic_inc(&state->count);
return state;
}
}
return NULL;
}
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(&owner->so_lock);
spin_lock(&inode->i_lock);
state = __nfs4_find_state_byowner(inode, owner);
if (state == NULL && new != NULL) {
state = new;
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);
/* 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);
spin_unlock(&owner->so_lock);
} else {
spin_unlock(&inode->i_lock);
spin_unlock(&owner->so_lock);
if (new)
nfs4_free_open_state(new);
}
out:
return state;
}
/*
* Beware! Caller must be holding exactly one
* reference to clp->cl_sem!
*/
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, &owner->so_lock))
return;
spin_lock(&inode->i_lock);
if (!list_empty(&state->inode_states))
list_del(&state->inode_states);
list_del(&state->open_states);
spin_unlock(&inode->i_lock);
spin_unlock(&owner->so_lock);
iput(inode);
nfs4_free_open_state(state);
nfs4_put_state_owner(owner);
}
/*
* Close the current file.
*/
void nfs4_close_state(struct nfs4_state *state, mode_t mode)
{
struct inode *inode = state->inode;
struct nfs4_state_owner *owner = state->owner;
int oldstate, newstate = 0;
atomic_inc(&owner->so_count);
/* Protect against nfs4_find_state() */
spin_lock(&owner->so_lock);
spin_lock(&inode->i_lock);
switch (mode & (FMODE_READ | FMODE_WRITE)) {
case FMODE_READ:
state->n_rdonly--;
break;
case FMODE_WRITE:
state->n_wronly--;
break;
case FMODE_READ|FMODE_WRITE:
state->n_rdwr--;
}
oldstate = newstate = state->state;
if (state->n_rdwr == 0) {
if (state->n_rdonly == 0)
newstate &= ~FMODE_READ;
if (state->n_wronly == 0)
newstate &= ~FMODE_WRITE;
}
if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
nfs4_state_set_mode_locked(state, newstate);
oldstate = newstate;
}
spin_unlock(&inode->i_lock);
spin_unlock(&owner->so_lock);
if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
return;
nfs4_put_open_state(state);
nfs4_put_state_owner(owner);
}
/*
* 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.
*
*/
static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
{
struct nfs4_lock_state *lsp;
struct nfs_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 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
*/
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;
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;
spin_lock(&sequence->lock);
list_del(&seqid->list);
spin_unlock(&sequence->lock);
rpc_wake_up(&sequence->wait);
kfree(seqid);
}
/*
* 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);
}
/*
* 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;
if (sequence->list.next == &seqid->list)
goto out;
spin_lock(&sequence->lock);
if (sequence->list.next != &seqid->list) {
rpc_sleep_on(&sequence->wait, task, NULL, NULL);
status = -EAGAIN;
}
spin_unlock(&sequence->lock);
out:
return status;
}
static int reclaimer(void *);
static inline void nfs4_clear_recover_bit(struct nfs_client *clp)
{
smp_mb__before_clear_bit();
clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
smp_mb__after_clear_bit();
wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
rpc_wake_up(&clp->cl_rpcwaitq);
}
/*
* State recovery routine
*/
static void nfs4_recover_state(struct nfs_client *clp)
{
struct task_struct *task;
__module_get(THIS_MODULE);
atomic_inc(&clp->cl_count);
task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
NIPQUAD(clp->cl_addr.sin_addr));
if (!IS_ERR(task))
return;
nfs4_clear_recover_bit(clp);
nfs_put_client(clp);
module_put(THIS_MODULE);
}
/*
* Schedule a state recovery attempt
*/
void nfs4_schedule_state_recovery(struct nfs_client *clp)
{
if (!clp)
return;
if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
nfs4_recover_state(clp);
}
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|FL_FLOCK)))
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_pid, 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 nfs_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;
spin_lock(&sp->so_lock);
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;
}
}
spin_unlock(&sp->so_lock);
}
}
static int reclaimer(void *ptr)
{
struct nfs_client *clp = ptr;
struct nfs4_state_owner *sp;
struct nfs4_state_recovery_ops *ops;
struct rpc_cred *cred;
int status = 0;
allow_signal(SIGKILL);
/* 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:
ops = &nfs4_network_partition_recovery_ops;
/* Are there any open files on this volume? */
cred = nfs4_get_renew_cred(clp);
if (cred != NULL) {
/* Yes there are: try to renew the old lease */
status = nfs4_proc_renew(clp, cred);
switch (status) {
case 0:
case -NFS4ERR_CB_PATH_DOWN:
put_rpccred(cred);
goto out;
case -NFS4ERR_STALE_CLIENTID:
case -NFS4ERR_LEASE_MOVED:
ops = &nfs4_reboot_recovery_ops;
}
} else {
/* "reboot" to ensure we clear all state on the server */
clp->cl_boot_time = CURRENT_TIME;
cred = nfs4_get_setclientid_cred(clp);
}
/* We're going to have to re-establish a clientid */
nfs4_state_mark_reclaim(clp);
status = -ENOENT;
if (cred != NULL) {
status = nfs4_init_client(clp, cred);
put_rpccred(cred);
}
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:
up_write(&clp->cl_sem);
unlock_kernel();
if (status == -NFS4ERR_CB_PATH_DOWN)
nfs_handle_cb_pathdown(clp);
nfs4_clear_recover_bit(clp);
nfs_put_client(clp);
module_put_and_exit(0);
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.sin_addr), -status);
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
goto out;
}
/*
* Local variables:
* c-basic-offset: 8
* End:
*/