/* * 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; }