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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/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);
- }
- 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;
- for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
- if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
- continue;
- if (nfs_file_open_context(fl->fl_file) != ctx)
- continue;
- status = nfs4_lock_delegation_recall(state, fl);
- if (status >= 0)
- continue;
- switch (status) {
- default:
- printk(KERN_ERR "%s: unhandled error %d.\n",
- __FUNCTION__, status);
- case -NFS4ERR_EXPIRED:
- /* kill_proc(fl->fl_pid, SIGLOST, 1); */
- case -NFS4ERR_STALE_CLIENTID:
- nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
- goto out_err;
- }
- }
- return 0;
- out_err:
- 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);
- delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
- NFS_I(inode)->delegation_state = delegation->type;
- smp_wmb();
- put_rpccred(oldcred);
- }
- /*
- * 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;
- 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;
- spin_lock(&clp->cl_lock);
- if (rcu_dereference(nfsi->delegation) == NULL) {
- list_add_rcu(&delegation->super_list, &clp->cl_delegations);
- nfsi->delegation_state = delegation->type;
- rcu_assign_pointer(nfsi->delegation, delegation);
- 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.sin_addr));
- status = -EIO;
- }
- }
- /* 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);
- spin_unlock(&clp->cl_lock);
- if (delegation != NULL)
- nfs_free_delegation(delegation);
- return status;
- }
- static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
- {
- int res = 0;
- 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
- */
- static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
- {
- struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
- struct nfs_inode *nfsi = NFS_I(inode);
- nfs_msync_inode(inode);
- down_read(&clp->cl_sem);
- /* Guard against new delegated open calls */
- down_write(&nfsi->rwsem);
- nfs_delegation_claim_opens(inode, &delegation->stateid);
- up_write(&nfsi->rwsem);
- up_read(&clp->cl_sem);
- nfs_msync_inode(inode);
- return nfs_do_return_delegation(inode, delegation);
- }
- 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;
- if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
- sizeof(delegation->stateid.data)) != 0)
- goto nomatch;
- list_del_rcu(&delegation->super_list);
- nfsi->delegation_state = 0;
- rcu_assign_pointer(nfsi->delegation, NULL);
- return delegation;
- nomatch:
- return NULL;
- }
- 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;
- }
- /*
- * Return all delegations associated to a super block
- */
- void nfs_return_all_delegations(struct super_block *sb)
- {
- struct nfs_client *clp = NFS_SB(sb)->nfs_client;
- struct nfs_delegation *delegation;
- struct inode *inode;
- if (clp == NULL)
- return;
- restart:
- rcu_read_lock();
- list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
- if (delegation->inode->i_sb != sb)
- continue;
- inode = igrab(delegation->inode);
- 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();
- }
- static int nfs_do_expire_all_delegations(void *ptr)
- {
- struct nfs_client *clp = ptr;
- struct nfs_delegation *delegation;
- struct inode *inode;
- allow_signal(SIGKILL);
- restart:
- if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
- goto out;
- if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
- goto out;
- rcu_read_lock();
- list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
- inode = igrab(delegation->inode);
- 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)
- __nfs_inode_return_delegation(inode, delegation);
- iput(inode);
- goto restart;
- }
- rcu_read_unlock();
- out:
- nfs_put_client(clp);
- module_put_and_exit(0);
- }
- void nfs_expire_all_delegations(struct nfs_client *clp)
- {
- struct task_struct *task;
- __module_get(THIS_MODULE);
- atomic_inc(&clp->cl_count);
- task = kthread_run(nfs_do_expire_all_delegations, clp,
- "%u.%u.%u.%u-delegreturn",
- NIPQUAD(clp->cl_addr.sin_addr));
- if (!IS_ERR(task))
- return;
- nfs_put_client(clp);
- module_put(THIS_MODULE);
- }
- /*
- * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
- */
- void nfs_handle_cb_pathdown(struct nfs_client *clp)
- {
- struct nfs_delegation *delegation;
- struct inode *inode;
- if (clp == NULL)
- return;
- restart:
- rcu_read_lock();
- list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
- inode = igrab(delegation->inode);
- 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();
- }
- struct recall_threadargs {
- struct inode *inode;
- struct nfs_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 nfs_client *clp = NFS_SERVER(inode)->nfs_client;
- 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 = nfs_detach_delegation_locked(nfsi, args->stateid);
- if (delegation != NULL)
- args->result = 0;
- else
- args->result = -ENOENT;
- spin_unlock(&clp->cl_lock);
- complete(&args->started);
- nfs_delegation_claim_opens(inode, args->stateid);
- 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 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) {
- if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
- res = igrab(delegation->inode);
- 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)
- delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
- 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;
- restart:
- rcu_read_lock();
- list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
- if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
- continue;
- spin_lock(&clp->cl_lock);
- delegation = nfs_detach_delegation_locked(NFS_I(delegation->inode), NULL);
- spin_unlock(&clp->cl_lock);
- rcu_read_unlock();
- if (delegation != NULL)
- nfs_free_delegation(delegation);
- 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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