android_kernel_xiaomi_sm8350/fs/nfs/delegation.c

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/*
* linux/fs/nfs/delegation.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFS file delegation management
*
*/
#include <linux/config.h>
#include <linux/completion.h>
#include <linux/module.h>
#include <linux/sched.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"
static struct nfs_delegation *nfs_alloc_delegation(void)
{
return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
}
static void nfs_free_delegation(struct nfs_delegation *delegation)
{
if (delegation->cred)
put_rpccred(delegation->cred);
kfree(delegation);
}
static void nfs_delegation_claim_opens(struct inode *inode)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *ctx;
struct nfs4_state *state;
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;
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
if (nfs4_open_delegation_recall(ctx->dentry, state) < 0)
return;
put_nfs_open_context(ctx);
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;
if (delegation == NULL)
return;
memcpy(delegation->stateid.data, res->delegation.data,
sizeof(delegation->stateid.data));
delegation->type = res->delegation_type;
delegation->maxsize = res->maxsize;
put_rpccred(cred);
delegation->cred = get_rpccred(cred);
delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
NFS_I(inode)->delegation_state = delegation->type;
smp_wmb();
}
/*
* Set up a delegation on an inode
*/
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int status = 0;
/* Ensure we first revalidate the attributes and page cache! */
if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
__nfs_revalidate_inode(NFS_SERVER(inode), inode);
delegation = nfs_alloc_delegation();
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->cred = get_rpccred(cred);
delegation->inode = inode;
spin_lock(&clp->cl_lock);
if (nfsi->delegation == NULL) {
list_add(&delegation->super_list, &clp->cl_delegations);
nfsi->delegation = delegation;
nfsi->delegation_state = delegation->type;
delegation = NULL;
} else {
if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
sizeof(delegation->stateid)) != 0 ||
delegation->type != nfsi->delegation->type) {
printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
__FUNCTION__, NIPQUAD(clp->cl_addr));
status = -EIO;
}
}
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
kfree(delegation);
return status;
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
{
int res = 0;
__nfs_revalidate_inode(NFS_SERVER(inode), inode);
res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
nfs_free_delegation(delegation);
return res;
}
/* 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
*/
int __nfs_inode_return_delegation(struct inode *inode)
{
struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int res = 0;
nfs_msync_inode(inode);
down_read(&clp->cl_sem);
/* Guard against new delegated open calls */
down_write(&nfsi->rwsem);
spin_lock(&clp->cl_lock);
delegation = nfsi->delegation;
if (delegation != NULL) {
list_del_init(&delegation->super_list);
nfsi->delegation = NULL;
nfsi->delegation_state = 0;
}
spin_unlock(&clp->cl_lock);
nfs_delegation_claim_opens(inode);
up_write(&nfsi->rwsem);
up_read(&clp->cl_sem);
nfs_msync_inode(inode);
if (delegation != NULL)
res = nfs_do_return_delegation(inode, delegation);
return res;
}
/*
* Return all delegations associated to a super block
*/
void nfs_return_all_delegations(struct super_block *sb)
{
struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
struct nfs_delegation *delegation;
struct inode *inode;
if (clp == NULL)
return;
restart:
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
if (delegation->inode->i_sb != sb)
continue;
inode = igrab(delegation->inode);
if (inode == NULL)
continue;
spin_unlock(&clp->cl_lock);
nfs_inode_return_delegation(inode);
iput(inode);
goto restart;
}
spin_unlock(&clp->cl_lock);
}
/*
* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
*/
void nfs_handle_cb_pathdown(struct nfs4_client *clp)
{
struct nfs_delegation *delegation;
struct inode *inode;
if (clp == NULL)
return;
restart:
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
inode = igrab(delegation->inode);
if (inode == NULL)
continue;
spin_unlock(&clp->cl_lock);
nfs_inode_return_delegation(inode);
iput(inode);
goto restart;
}
spin_unlock(&clp->cl_lock);
}
struct recall_threadargs {
struct inode *inode;
struct nfs4_client *clp;
const nfs4_stateid *stateid;
struct completion started;
int result;
};
static int recall_thread(void *data)
{
struct recall_threadargs *args = (struct recall_threadargs *)data;
struct inode *inode = igrab(args->inode);
struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
daemonize("nfsv4-delegreturn");
nfs_msync_inode(inode);
down_read(&clp->cl_sem);
down_write(&nfsi->rwsem);
spin_lock(&clp->cl_lock);
delegation = nfsi->delegation;
if (delegation != NULL && memcmp(delegation->stateid.data,
args->stateid->data,
sizeof(delegation->stateid.data)) == 0) {
list_del_init(&delegation->super_list);
nfsi->delegation = NULL;
nfsi->delegation_state = 0;
args->result = 0;
} else {
delegation = NULL;
args->result = -ENOENT;
}
spin_unlock(&clp->cl_lock);
complete(&args->started);
nfs_delegation_claim_opens(inode);
up_write(&nfsi->rwsem);
up_read(&clp->cl_sem);
nfs_msync_inode(inode);
if (delegation != NULL)
nfs_do_return_delegation(inode, delegation);
iput(inode);
module_put_and_exit(0);
}
/*
* Asynchronous delegation recall!
*/
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
{
struct recall_threadargs data = {
.inode = inode,
.stateid = stateid,
};
int status;
init_completion(&data.started);
__module_get(THIS_MODULE);
status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
if (status < 0)
goto out_module_put;
wait_for_completion(&data.started);
return data.result;
out_module_put:
module_put(THIS_MODULE);
return status;
}
/*
* Retrieve the inode associated with a delegation
*/
struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle)
{
struct nfs_delegation *delegation;
struct inode *res = NULL;
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
res = igrab(delegation->inode);
break;
}
}
spin_unlock(&clp->cl_lock);
return res;
}
/*
* Mark all delegations as needing to be reclaimed
*/
void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
{
struct nfs_delegation *delegation;
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list)
delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
spin_unlock(&clp->cl_lock);
}
/*
* Reap all unclaimed delegations after reboot recovery is done
*/
void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
{
struct nfs_delegation *delegation, *n;
LIST_HEAD(head);
spin_lock(&clp->cl_lock);
list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
continue;
list_move(&delegation->super_list, &head);
NFS_I(delegation->inode)->delegation = NULL;
NFS_I(delegation->inode)->delegation_state = 0;
}
spin_unlock(&clp->cl_lock);
while(!list_empty(&head)) {
delegation = list_entry(head.next, struct nfs_delegation, super_list);
list_del(&delegation->super_list);
nfs_free_delegation(delegation);
}
}