| /* |
| * 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/smp_lock.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); |
| } |
| |
| void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) |
| { |
| set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); |
| } |
| |
| int nfs_have_delegation(struct inode *inode, fmode_t flags) |
| { |
| struct nfs_delegation *delegation; |
| int ret = 0; |
| |
| flags &= FMODE_READ|FMODE_WRITE; |
| rcu_read_lock(); |
| delegation = rcu_dereference(NFS_I(inode)->delegation); |
| if (delegation != NULL && (delegation->type & flags) == flags) { |
| nfs_mark_delegation_referenced(delegation); |
| ret = 1; |
| } |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| 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 = 0; |
| |
| if (inode->i_flock == NULL) |
| goto out; |
| |
| /* Protect inode->i_flock using the BKL */ |
| lock_kernel(); |
| for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { |
| if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK))) |
| continue; |
| if (nfs_file_open_context(fl->fl_file) != ctx) |
| continue; |
| unlock_kernel(); |
| status = nfs4_lock_delegation_recall(state, fl); |
| if (status < 0) |
| goto out; |
| lock_kernel(); |
| } |
| unlock_kernel(); |
| out: |
| return status; |
| } |
| |
| static int 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 err; |
| goto again; |
| } |
| spin_unlock(&inode->i_lock); |
| return 0; |
| } |
| |
| /* |
| * 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); |
| clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); |
| NFS_I(inode)->delegation_state = delegation->type; |
| smp_wmb(); |
| put_rpccred(oldcred); |
| } |
| |
| static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) |
| { |
| int res = 0; |
| |
| res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync); |
| nfs_free_delegation(delegation); |
| return res; |
| } |
| |
| static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) |
| { |
| struct inode *inode = NULL; |
| |
| spin_lock(&delegation->lock); |
| if (delegation->inode != NULL) |
| inode = igrab(delegation->inode); |
| spin_unlock(&delegation->lock); |
| return inode; |
| } |
| |
| 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; |
| spin_lock(&delegation->lock); |
| if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data, |
| sizeof(delegation->stateid.data)) != 0) |
| goto nomatch_unlock; |
| list_del_rcu(&delegation->super_list); |
| delegation->inode = NULL; |
| nfsi->delegation_state = 0; |
| rcu_assign_pointer(nfsi->delegation, NULL); |
| spin_unlock(&delegation->lock); |
| return delegation; |
| nomatch_unlock: |
| spin_unlock(&delegation->lock); |
| nomatch: |
| return NULL; |
| } |
| |
| /* |
| * 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; |
| struct nfs_delegation *freeme = NULL; |
| 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; |
| delegation->flags = 1<<NFS_DELEGATION_REFERENCED; |
| spin_lock_init(&delegation->lock); |
| |
| spin_lock(&clp->cl_lock); |
| if (rcu_dereference(nfsi->delegation) != NULL) { |
| if (memcmp(&delegation->stateid, &nfsi->delegation->stateid, |
| sizeof(delegation->stateid)) == 0 && |
| delegation->type == nfsi->delegation->type) { |
| goto out; |
| } |
| /* |
| * Deal with broken servers that hand out two |
| * delegations for the same file. |
| */ |
| dfprintk(FILE, "%s: server %s handed out " |
| "a duplicate delegation!\n", |
| __func__, clp->cl_hostname); |
| if (delegation->type <= nfsi->delegation->type) { |
| freeme = delegation; |
| delegation = NULL; |
| goto out; |
| } |
| freeme = nfs_detach_delegation_locked(nfsi, NULL); |
| } |
| list_add_rcu(&delegation->super_list, &clp->cl_delegations); |
| nfsi->delegation_state = delegation->type; |
| rcu_assign_pointer(nfsi->delegation, delegation); |
| delegation = NULL; |
| |
| /* 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); |
| |
| out: |
| spin_unlock(&clp->cl_lock); |
| if (delegation != NULL) |
| nfs_free_delegation(delegation); |
| if (freeme != NULL) |
| nfs_do_return_delegation(inode, freeme, 0); |
| return status; |
| } |
| |
| /* 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, int issync) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| int err; |
| |
| /* |
| * Guard against new delegated open/lock/unlock calls and against |
| * state recovery |
| */ |
| down_write(&nfsi->rwsem); |
| err = nfs_delegation_claim_opens(inode, &delegation->stateid); |
| up_write(&nfsi->rwsem); |
| if (err) |
| goto out; |
| |
| err = nfs_do_return_delegation(inode, delegation, issync); |
| out: |
| return err; |
| } |
| |
| /* |
| * Return all delegations that have been marked for return |
| */ |
| int nfs_client_return_marked_delegations(struct nfs_client *clp) |
| { |
| struct nfs_delegation *delegation; |
| struct inode *inode; |
| int err = 0; |
| |
| restart: |
| rcu_read_lock(); |
| list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { |
| if (!test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) |
| continue; |
| inode = nfs_delegation_grab_inode(delegation); |
| 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) { |
| filemap_flush(inode->i_mapping); |
| err = __nfs_inode_return_delegation(inode, delegation, 0); |
| } |
| iput(inode); |
| if (!err) |
| goto restart; |
| set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
| return err; |
| } |
| rcu_read_unlock(); |
| return 0; |
| } |
| |
| /* |
| * This function returns the delegation without reclaiming opens |
| * or protecting against delegation reclaims. |
| * It is therefore really only safe to be called from |
| * nfs4_clear_inode() |
| */ |
| void nfs_inode_return_delegation_noreclaim(struct inode *inode) |
| { |
| struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; |
| struct nfs_inode *nfsi = NFS_I(inode); |
| struct nfs_delegation *delegation; |
| |
| 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) |
| nfs_do_return_delegation(inode, delegation, 0); |
| } |
| } |
| |
| 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) { |
| nfs_msync_inode(inode); |
| err = __nfs_inode_return_delegation(inode, delegation, 1); |
| } |
| } |
| return err; |
| } |
| |
| static void nfs_mark_return_delegation(struct nfs_client *clp, struct nfs_delegation *delegation) |
| { |
| set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
| } |
| |
| /* |
| * Return all delegations associated to a super block |
| */ |
| void nfs_super_return_all_delegations(struct super_block *sb) |
| { |
| struct nfs_client *clp = NFS_SB(sb)->nfs_client; |
| struct nfs_delegation *delegation; |
| |
| if (clp == NULL) |
| return; |
| rcu_read_lock(); |
| list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { |
| spin_lock(&delegation->lock); |
| if (delegation->inode != NULL && delegation->inode->i_sb == sb) |
| set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| spin_unlock(&delegation->lock); |
| } |
| rcu_read_unlock(); |
| if (nfs_client_return_marked_delegations(clp) != 0) |
| nfs4_schedule_state_manager(clp); |
| } |
| |
| static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) |
| { |
| struct nfs_delegation *delegation; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { |
| set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void nfs_delegation_run_state_manager(struct nfs_client *clp) |
| { |
| if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) |
| nfs4_schedule_state_manager(clp); |
| } |
| |
| void nfs_expire_all_delegations(struct nfs_client *clp) |
| { |
| nfs_client_mark_return_all_delegations(clp); |
| nfs_delegation_run_state_manager(clp); |
| } |
| |
| /* |
| * Return all delegations following an NFS4ERR_CB_PATH_DOWN error. |
| */ |
| void nfs_handle_cb_pathdown(struct nfs_client *clp) |
| { |
| if (clp == NULL) |
| return; |
| nfs_client_mark_return_all_delegations(clp); |
| } |
| |
| static void nfs_client_mark_return_unreferenced_delegations(struct nfs_client *clp) |
| { |
| struct nfs_delegation *delegation; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { |
| if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) |
| continue; |
| set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
| } |
| rcu_read_unlock(); |
| } |
| |
| void nfs_expire_unreferenced_delegations(struct nfs_client *clp) |
| { |
| nfs_client_mark_return_unreferenced_delegations(clp); |
| nfs_delegation_run_state_manager(clp); |
| } |
| |
| /* |
| * Asynchronous delegation recall! |
| */ |
| int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid) |
| { |
| struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; |
| struct nfs_delegation *delegation; |
| |
| rcu_read_lock(); |
| delegation = rcu_dereference(NFS_I(inode)->delegation); |
| if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data, |
| sizeof(delegation->stateid.data)) != 0) { |
| rcu_read_unlock(); |
| return -ENOENT; |
| } |
| nfs_mark_return_delegation(clp, delegation); |
| rcu_read_unlock(); |
| nfs_delegation_run_state_manager(clp); |
| return 0; |
| } |
| |
| /* |
| * 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) { |
| spin_lock(&delegation->lock); |
| if (delegation->inode != NULL && |
| nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { |
| res = igrab(delegation->inode); |
| } |
| spin_unlock(&delegation->lock); |
| if (res != NULL) |
| 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) |
| set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); |
| 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; |
| struct inode *inode; |
| restart: |
| rcu_read_lock(); |
| list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { |
| if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0) |
| continue; |
| inode = nfs_delegation_grab_inode(delegation); |
| 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_free_delegation(delegation); |
| iput(inode); |
| 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; |
| } |