d18cc1fda2
The nfsv4 state manager could potentially deadlock inside __nfs_inode_return_delegation() if the server reboots, so that the calls to nfs_msync_inode() end up waiting on state recovery to complete. Also ensure that if a server reboot or network partition causes us to have to stop returning delegations, that NFS4CLNT_DELEGRETURN is set so that the state manager can resume any outstanding delegation returns after it has dealt with the state recovery situation. Finally, ensure that the state manager doesn't wait for the DELEGRETURN call to complete. It doesn't need to, and that too can cause a deadlock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
539 lines
14 KiB
C
539 lines
14 KiB
C
/*
|
|
* 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 int 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 err;
|
|
goto again;
|
|
}
|
|
spin_unlock(&inode->i_lock);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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, int issync)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
int err;
|
|
|
|
/*
|
|
* Guard against new delegated open/lock/unlock calls and against
|
|
* state recovery
|
|
*/
|
|
down_write(&nfsi->rwsem);
|
|
err = nfs_delegation_claim_opens(inode, &delegation->stateid);
|
|
up_write(&nfsi->rwsem);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = nfs_do_return_delegation(inode, delegation, issync);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Return all delegations that have been marked for return
|
|
*/
|
|
int nfs_client_return_marked_delegations(struct nfs_client *clp)
|
|
{
|
|
struct nfs_delegation *delegation;
|
|
struct inode *inode;
|
|
int err = 0;
|
|
|
|
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) {
|
|
filemap_flush(inode->i_mapping);
|
|
err = __nfs_inode_return_delegation(inode, delegation, 0);
|
|
}
|
|
iput(inode);
|
|
if (!err)
|
|
goto restart;
|
|
set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
|
|
return err;
|
|
}
|
|
rcu_read_unlock();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
nfs_msync_inode(inode);
|
|
err = __nfs_inode_return_delegation(inode, delegation, 1);
|
|
}
|
|
}
|
|
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();
|
|
if (nfs_client_return_marked_delegations(clp) != 0)
|
|
nfs4_schedule_state_manager(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;
|
|
}
|