| /* |
| * 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_free_delegation(struct nfs_delegation *delegation) |
| { |
| if (delegation->cred) |
| put_rpccred(delegation->cred); |
| kfree(delegation); |
| } |
| |
| 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 ((struct nfs_open_context *)fl->fl_file->private_data != 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; |
| |
| 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 nfs_client *clp = NFS_SERVER(inode)->nfs_client; |
| 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 = 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 (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.sin_addr)); |
| status = -EIO; |
| } |
| } |
| spin_unlock(&clp->cl_lock); |
| kfree(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 = 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_init(&delegation->super_list); |
| nfsi->delegation = NULL; |
| nfsi->delegation_state = 0; |
| 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 (nfsi->delegation_state != 0) { |
| 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: |
| 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; |
| nfs_detach_delegation_locked(NFS_I(inode), NULL); |
| spin_unlock(&clp->cl_lock); |
| __nfs_inode_return_delegation(inode, delegation); |
| iput(inode); |
| goto restart; |
| } |
| spin_unlock(&clp->cl_lock); |
| } |
| |
| 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: |
| spin_lock(&clp->cl_lock); |
| if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0) |
| goto out; |
| if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) |
| goto out; |
| list_for_each_entry(delegation, &clp->cl_delegations, super_list) { |
| inode = igrab(delegation->inode); |
| if (inode == NULL) |
| continue; |
| nfs_detach_delegation_locked(NFS_I(inode), NULL); |
| spin_unlock(&clp->cl_lock); |
| __nfs_inode_return_delegation(inode, delegation); |
| iput(inode); |
| goto restart; |
| } |
| out: |
| spin_unlock(&clp->cl_lock); |
| 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: |
| spin_lock(&clp->cl_lock); |
| list_for_each_entry(delegation, &clp->cl_delegations, super_list) { |
| inode = igrab(delegation->inode); |
| if (inode == NULL) |
| continue; |
| nfs_detach_delegation_locked(NFS_I(inode), NULL); |
| spin_unlock(&clp->cl_lock); |
| __nfs_inode_return_delegation(inode, delegation); |
| iput(inode); |
| goto restart; |
| } |
| spin_unlock(&clp->cl_lock); |
| } |
| |
| 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; |
| 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 nfs_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 nfs_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); |
| } |
| } |
| |
| int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode) |
| { |
| struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; |
| struct nfs_inode *nfsi = NFS_I(inode); |
| struct nfs_delegation *delegation; |
| int res = 0; |
| |
| if (nfsi->delegation_state == 0) |
| return 0; |
| spin_lock(&clp->cl_lock); |
| delegation = nfsi->delegation; |
| if (delegation != NULL) { |
| memcpy(dst->data, delegation->stateid.data, sizeof(dst->data)); |
| res = 1; |
| } |
| spin_unlock(&clp->cl_lock); |
| return res; |
| } |