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linux-next/fs/nfs/delegation.c
Alexey Dobriyan 405f55712d headers: smp_lock.h redux 
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00

525 lines
14 KiB
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/*
* linux/fs/nfs/delegation.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFS file delegation management
*
*/
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>
#include "nfs4_fs.h"
#include "delegation.h"
#include "internal.h"
static void nfs_do_free_delegation(struct nfs_delegation *delegation)
{
kfree(delegation);
}
static void nfs_free_delegation_callback(struct rcu_head *head)
{
struct nfs_delegation *delegation = container_of(head, struct nfs_delegation, rcu);
nfs_do_free_delegation(delegation);
}
static void nfs_free_delegation(struct nfs_delegation *delegation)
{
struct rpc_cred *cred;
cred = rcu_dereference(delegation->cred);
rcu_assign_pointer(delegation->cred, NULL);
call_rcu(&delegation->rcu, nfs_free_delegation_callback);
if (cred)
put_rpccred(cred);
}
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
{
set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
}
int nfs_have_delegation(struct inode *inode, fmode_t flags)
{
struct nfs_delegation *delegation;
int ret = 0;
flags &= FMODE_READ|FMODE_WRITE;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (delegation != NULL && (delegation->type & flags) == flags) {
nfs_mark_delegation_referenced(delegation);
ret = 1;
}
rcu_read_unlock();
return ret;
}
static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
{
struct inode *inode = state->inode;
struct file_lock *fl;
int status = 0;
if (inode->i_flock == NULL)
goto out;
/* Protect inode->i_flock using the BKL */
lock_kernel();
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
continue;
if (nfs_file_open_context(fl->fl_file) != ctx)
continue;
unlock_kernel();
status = nfs4_lock_delegation_recall(state, fl);
if (status < 0)
goto out;
lock_kernel();
}
unlock_kernel();
out:
return status;
}
static void nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *ctx;
struct nfs4_state *state;
int err;
again:
spin_lock(&inode->i_lock);
list_for_each_entry(ctx, &nfsi->open_files, list) {
state = ctx->state;
if (state == NULL)
continue;
if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
continue;
if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
continue;
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
err = nfs4_open_delegation_recall(ctx, state, stateid);
if (err >= 0)
err = nfs_delegation_claim_locks(ctx, state);
put_nfs_open_context(ctx);
if (err != 0)
return;
goto again;
}
spin_unlock(&inode->i_lock);
}
/*
* Set up a delegation on an inode
*/
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
struct nfs_delegation *delegation = NFS_I(inode)->delegation;
struct rpc_cred *oldcred;
if (delegation == NULL)
return;
memcpy(delegation->stateid.data, res->delegation.data,
sizeof(delegation->stateid.data));
delegation->type = res->delegation_type;
delegation->maxsize = res->maxsize;
oldcred = delegation->cred;
delegation->cred = get_rpccred(cred);
clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
NFS_I(inode)->delegation_state = delegation->type;
smp_wmb();
put_rpccred(oldcred);
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
int res = 0;
res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
nfs_free_delegation(delegation);
return res;
}
static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
{
struct inode *inode = NULL;
spin_lock(&delegation->lock);
if (delegation->inode != NULL)
inode = igrab(delegation->inode);
spin_unlock(&delegation->lock);
return inode;
}
static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
{
struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL)
goto nomatch;
spin_lock(&delegation->lock);
if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
sizeof(delegation->stateid.data)) != 0)
goto nomatch_unlock;
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_unlock:
spin_unlock(&delegation->lock);
nomatch:
return NULL;
}
/*
* Set up a delegation on an inode
*/
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
struct nfs_delegation *freeme = NULL;
int status = 0;
delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
if (delegation == NULL)
return -ENOMEM;
memcpy(delegation->stateid.data, res->delegation.data,
sizeof(delegation->stateid.data));
delegation->type = res->delegation_type;
delegation->maxsize = res->maxsize;
delegation->change_attr = nfsi->change_attr;
delegation->cred = get_rpccred(cred);
delegation->inode = inode;
delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
spin_lock_init(&delegation->lock);
spin_lock(&clp->cl_lock);
if (rcu_dereference(nfsi->delegation) != NULL) {
if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
sizeof(delegation->stateid)) == 0 &&
delegation->type == nfsi->delegation->type) {
goto out;
}
/*
* Deal with broken servers that hand out two
* delegations for the same file.
*/
dfprintk(FILE, "%s: server %s handed out "
"a duplicate delegation!\n",
__func__, clp->cl_hostname);
if (delegation->type <= nfsi->delegation->type) {
freeme = delegation;
delegation = NULL;
goto out;
}
freeme = nfs_detach_delegation_locked(nfsi, NULL);
}
list_add_rcu(&delegation->super_list, &clp->cl_delegations);
nfsi->delegation_state = delegation->type;
rcu_assign_pointer(nfsi->delegation, delegation);
delegation = NULL;
/* Ensure we revalidate the attributes and page cache! */
spin_lock(&inode->i_lock);
nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
spin_unlock(&inode->i_lock);
out:
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
nfs_free_delegation(delegation);
if (freeme != NULL)
nfs_do_return_delegation(inode, freeme, 0);
return status;
}
/* Sync all data to disk upon delegation return */
static void nfs_msync_inode(struct inode *inode)
{
filemap_fdatawrite(inode->i_mapping);
nfs_wb_all(inode);
filemap_fdatawait(inode->i_mapping);
}
/*
* Basic procedure for returning a delegation to the server
*/
static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
{
struct nfs_inode *nfsi = NFS_I(inode);
nfs_msync_inode(inode);
/*
* Guard against new delegated open/lock/unlock calls and against
* state recovery
*/
down_write(&nfsi->rwsem);
nfs_delegation_claim_opens(inode, &delegation->stateid);
up_write(&nfsi->rwsem);
nfs_msync_inode(inode);
return nfs_do_return_delegation(inode, delegation, 1);
}
/*
* Return all delegations that have been marked for return
*/
void nfs_client_return_marked_delegations(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
struct inode *inode;
restart:
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
if (!test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
continue;
inode = nfs_delegation_grab_inode(delegation);
if (inode == NULL)
continue;
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
spin_unlock(&clp->cl_lock);
rcu_read_unlock();
if (delegation != NULL)
__nfs_inode_return_delegation(inode, delegation);
iput(inode);
goto restart;
}
rcu_read_unlock();
}
/*
* This function returns the delegation without reclaiming opens
* or protecting against delegation reclaims.
* It is therefore really only safe to be called from
* nfs4_clear_inode()
*/
void nfs_inode_return_delegation_noreclaim(struct inode *inode)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
if (rcu_dereference(nfsi->delegation) != NULL) {
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(nfsi, NULL);
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
nfs_do_return_delegation(inode, delegation, 0);
}
}
int nfs_inode_return_delegation(struct inode *inode)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int err = 0;
if (rcu_dereference(nfsi->delegation) != NULL) {
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(nfsi, NULL);
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
err = __nfs_inode_return_delegation(inode, delegation);
}
return err;
}
static void nfs_mark_return_delegation(struct nfs_client *clp, struct nfs_delegation *delegation)
{
set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
}
/*
* Return all delegations associated to a super block
*/
void nfs_super_return_all_delegations(struct super_block *sb)
{
struct nfs_client *clp = NFS_SB(sb)->nfs_client;
struct nfs_delegation *delegation;
if (clp == NULL)
return;
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
spin_lock(&delegation->lock);
if (delegation->inode != NULL && delegation->inode->i_sb == sb)
set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
spin_unlock(&delegation->lock);
}
rcu_read_unlock();
nfs_client_return_marked_delegations(clp);
}
static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
}
rcu_read_unlock();
}
static void nfs_delegation_run_state_manager(struct nfs_client *clp)
{
if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
nfs4_schedule_state_manager(clp);
}
void nfs_expire_all_delegations(struct nfs_client *clp)
{
nfs_client_mark_return_all_delegations(clp);
nfs_delegation_run_state_manager(clp);
}
/*
* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
*/
void nfs_handle_cb_pathdown(struct nfs_client *clp)
{
if (clp == NULL)
return;
nfs_client_mark_return_all_delegations(clp);
}
static void nfs_client_mark_return_unreferenced_delegations(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
continue;
set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
}
rcu_read_unlock();
}
void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
{
nfs_client_mark_return_unreferenced_delegations(clp);
nfs_delegation_run_state_manager(clp);
}
/*
* Asynchronous delegation recall!
*/
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_delegation *delegation;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
sizeof(delegation->stateid.data)) != 0) {
rcu_read_unlock();
return -ENOENT;
}
nfs_mark_return_delegation(clp, delegation);
rcu_read_unlock();
nfs_delegation_run_state_manager(clp);
return 0;
}
/*
* Retrieve the inode associated with a delegation
*/
struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
{
struct nfs_delegation *delegation;
struct inode *res = NULL;
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
spin_lock(&delegation->lock);
if (delegation->inode != NULL &&
nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
res = igrab(delegation->inode);
}
spin_unlock(&delegation->lock);
if (res != NULL)
break;
}
rcu_read_unlock();
return res;
}
/*
* Mark all delegations as needing to be reclaimed
*/
void nfs_delegation_mark_reclaim(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list)
set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
rcu_read_unlock();
}
/*
* Reap all unclaimed delegations after reboot recovery is done
*/
void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
struct inode *inode;
restart:
rcu_read_lock();
list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0)
continue;
inode = nfs_delegation_grab_inode(delegation);
if (inode == NULL)
continue;
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
spin_unlock(&clp->cl_lock);
rcu_read_unlock();
if (delegation != NULL)
nfs_free_delegation(delegation);
iput(inode);
goto restart;
}
rcu_read_unlock();
}
int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int ret = 0;
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
if (delegation != NULL) {
memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
ret = 1;
}
rcu_read_unlock();
return ret;
}
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