/* * 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; 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); } }