706 lines
18 KiB
C
706 lines
18 KiB
C
/*
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* linux/fs/nfs/delegation.c
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*
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* Copyright (C) 2004 Trond Myklebust
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*
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* NFS file delegation management
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*
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*/
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#include <linux/completion.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/nfs4.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_xdr.h>
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#include "nfs4_fs.h"
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#include "delegation.h"
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#include "internal.h"
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static void nfs_free_delegation(struct nfs_delegation *delegation)
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{
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if (delegation->cred) {
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put_rpccred(delegation->cred);
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delegation->cred = NULL;
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}
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kfree_rcu(delegation, rcu);
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}
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/**
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* nfs_mark_delegation_referenced - set delegation's REFERENCED flag
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* @delegation: delegation to process
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*
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*/
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void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
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{
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set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
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}
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/**
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* nfs_have_delegation - check if inode has a delegation
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* @inode: inode to check
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* @flags: delegation types to check for
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*
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* Returns one if inode has the indicated delegation, otherwise zero.
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*/
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int nfs_have_delegation(struct inode *inode, fmode_t flags)
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{
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struct nfs_delegation *delegation;
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int ret = 0;
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flags &= FMODE_READ|FMODE_WRITE;
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rcu_read_lock();
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delegation = rcu_dereference(NFS_I(inode)->delegation);
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if (delegation != NULL && (delegation->type & flags) == flags) {
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nfs_mark_delegation_referenced(delegation);
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ret = 1;
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}
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rcu_read_unlock();
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return ret;
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}
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static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
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{
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struct inode *inode = state->inode;
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struct file_lock *fl;
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int status = 0;
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if (inode->i_flock == NULL)
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goto out;
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/* Protect inode->i_flock using the file locks lock */
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lock_flocks();
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for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
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if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
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continue;
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if (nfs_file_open_context(fl->fl_file) != ctx)
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continue;
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unlock_flocks();
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status = nfs4_lock_delegation_recall(state, fl);
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if (status < 0)
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goto out;
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lock_flocks();
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}
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unlock_flocks();
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out:
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return status;
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}
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static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
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{
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_open_context *ctx;
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struct nfs4_state *state;
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int err;
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again:
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spin_lock(&inode->i_lock);
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list_for_each_entry(ctx, &nfsi->open_files, list) {
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state = ctx->state;
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if (state == NULL)
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continue;
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if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
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continue;
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if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
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continue;
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get_nfs_open_context(ctx);
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spin_unlock(&inode->i_lock);
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err = nfs4_open_delegation_recall(ctx, state, stateid);
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if (err >= 0)
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err = nfs_delegation_claim_locks(ctx, state);
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put_nfs_open_context(ctx);
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if (err != 0)
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return err;
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goto again;
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}
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spin_unlock(&inode->i_lock);
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return 0;
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}
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/**
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* nfs_inode_reclaim_delegation - process a delegation reclaim request
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* @inode: inode to process
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* @cred: credential to use for request
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* @res: new delegation state from server
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*
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*/
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void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
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struct nfs_openres *res)
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{
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struct nfs_delegation *delegation;
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struct rpc_cred *oldcred = NULL;
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rcu_read_lock();
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delegation = rcu_dereference(NFS_I(inode)->delegation);
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if (delegation != NULL) {
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spin_lock(&delegation->lock);
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if (delegation->inode != NULL) {
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memcpy(delegation->stateid.data, res->delegation.data,
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sizeof(delegation->stateid.data));
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delegation->type = res->delegation_type;
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delegation->maxsize = res->maxsize;
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oldcred = delegation->cred;
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delegation->cred = get_rpccred(cred);
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clear_bit(NFS_DELEGATION_NEED_RECLAIM,
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&delegation->flags);
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NFS_I(inode)->delegation_state = delegation->type;
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spin_unlock(&delegation->lock);
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put_rpccred(oldcred);
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rcu_read_unlock();
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} else {
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/* We appear to have raced with a delegation return. */
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spin_unlock(&delegation->lock);
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rcu_read_unlock();
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nfs_inode_set_delegation(inode, cred, res);
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}
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} else {
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rcu_read_unlock();
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}
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}
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static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
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{
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int res = 0;
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res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
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nfs_free_delegation(delegation);
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return res;
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}
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static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
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{
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struct inode *inode = NULL;
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spin_lock(&delegation->lock);
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if (delegation->inode != NULL)
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inode = igrab(delegation->inode);
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spin_unlock(&delegation->lock);
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return inode;
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}
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static struct nfs_delegation *
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nfs_detach_delegation_locked(struct nfs_inode *nfsi,
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struct nfs_server *server)
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{
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struct nfs_delegation *delegation =
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rcu_dereference_protected(nfsi->delegation,
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lockdep_is_held(&server->nfs_client->cl_lock));
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if (delegation == NULL)
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goto nomatch;
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spin_lock(&delegation->lock);
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list_del_rcu(&delegation->super_list);
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delegation->inode = NULL;
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nfsi->delegation_state = 0;
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rcu_assign_pointer(nfsi->delegation, NULL);
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spin_unlock(&delegation->lock);
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return delegation;
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nomatch:
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return NULL;
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}
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static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
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struct nfs_server *server)
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{
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struct nfs_client *clp = server->nfs_client;
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struct nfs_delegation *delegation;
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(nfsi, server);
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spin_unlock(&clp->cl_lock);
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return delegation;
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}
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/**
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* nfs_inode_set_delegation - set up a delegation on an inode
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* @inode: inode to which delegation applies
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* @cred: cred to use for subsequent delegation processing
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* @res: new delegation state from server
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*
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* Returns zero on success, or a negative errno value.
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*/
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int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_client *clp = server->nfs_client;
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_delegation *delegation, *old_delegation;
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struct nfs_delegation *freeme = NULL;
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int status = 0;
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delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
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if (delegation == NULL)
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return -ENOMEM;
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memcpy(delegation->stateid.data, res->delegation.data,
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sizeof(delegation->stateid.data));
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delegation->type = res->delegation_type;
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delegation->maxsize = res->maxsize;
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delegation->change_attr = nfsi->change_attr;
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delegation->cred = get_rpccred(cred);
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delegation->inode = inode;
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delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
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spin_lock_init(&delegation->lock);
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spin_lock(&clp->cl_lock);
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old_delegation = rcu_dereference_protected(nfsi->delegation,
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lockdep_is_held(&clp->cl_lock));
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if (old_delegation != NULL) {
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if (memcmp(&delegation->stateid, &old_delegation->stateid,
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sizeof(old_delegation->stateid)) == 0 &&
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delegation->type == old_delegation->type) {
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goto out;
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}
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/*
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* Deal with broken servers that hand out two
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* delegations for the same file.
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*/
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dfprintk(FILE, "%s: server %s handed out "
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"a duplicate delegation!\n",
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__func__, clp->cl_hostname);
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if (delegation->type <= old_delegation->type) {
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freeme = delegation;
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delegation = NULL;
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goto out;
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}
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freeme = nfs_detach_delegation_locked(nfsi, server);
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}
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list_add_rcu(&delegation->super_list, &server->delegations);
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nfsi->delegation_state = delegation->type;
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rcu_assign_pointer(nfsi->delegation, delegation);
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delegation = NULL;
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/* Ensure we revalidate the attributes and page cache! */
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spin_lock(&inode->i_lock);
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nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
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spin_unlock(&inode->i_lock);
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out:
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spin_unlock(&clp->cl_lock);
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if (delegation != NULL)
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nfs_free_delegation(delegation);
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if (freeme != NULL)
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nfs_do_return_delegation(inode, freeme, 0);
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return status;
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}
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/*
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* Basic procedure for returning a delegation to the server
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*/
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static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
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{
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struct nfs_inode *nfsi = NFS_I(inode);
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int err;
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/*
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* Guard against new delegated open/lock/unlock calls and against
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* state recovery
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*/
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down_write(&nfsi->rwsem);
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err = nfs_delegation_claim_opens(inode, &delegation->stateid);
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up_write(&nfsi->rwsem);
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if (err)
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goto out;
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err = nfs_do_return_delegation(inode, delegation, issync);
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out:
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return err;
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}
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/**
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* nfs_client_return_marked_delegations - return previously marked delegations
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* @clp: nfs_client to process
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*
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* Returns zero on success, or a negative errno value.
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*/
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int nfs_client_return_marked_delegations(struct nfs_client *clp)
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{
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struct nfs_delegation *delegation;
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struct nfs_server *server;
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struct inode *inode;
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int err = 0;
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restart:
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rcu_read_lock();
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list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
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list_for_each_entry_rcu(delegation, &server->delegations,
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super_list) {
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if (!test_and_clear_bit(NFS_DELEGATION_RETURN,
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&delegation->flags))
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continue;
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inode = nfs_delegation_grab_inode(delegation);
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if (inode == NULL)
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continue;
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delegation = nfs_detach_delegation(NFS_I(inode),
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server);
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rcu_read_unlock();
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if (delegation != NULL) {
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filemap_flush(inode->i_mapping);
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err = __nfs_inode_return_delegation(inode,
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delegation, 0);
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}
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iput(inode);
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if (!err)
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goto restart;
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set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
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return err;
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}
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}
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rcu_read_unlock();
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return 0;
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}
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/**
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* nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
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* @inode: inode to process
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*
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* Does not protect against delegation reclaims, therefore really only safe
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* to be called from nfs4_clear_inode().
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*/
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void nfs_inode_return_delegation_noreclaim(struct inode *inode)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_delegation *delegation;
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if (rcu_access_pointer(nfsi->delegation) != NULL) {
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delegation = nfs_detach_delegation(nfsi, server);
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if (delegation != NULL)
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nfs_do_return_delegation(inode, delegation, 0);
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}
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}
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/**
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* nfs_inode_return_delegation - synchronously return a delegation
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* @inode: inode to process
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*
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* Returns zero on success, or a negative errno value.
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*/
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int nfs_inode_return_delegation(struct inode *inode)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_delegation *delegation;
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int err = 0;
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if (rcu_access_pointer(nfsi->delegation) != NULL) {
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delegation = nfs_detach_delegation(nfsi, server);
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if (delegation != NULL) {
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nfs_wb_all(inode);
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err = __nfs_inode_return_delegation(inode, delegation, 1);
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}
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}
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return err;
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}
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static void nfs_mark_return_delegation(struct nfs_server *server,
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struct nfs_delegation *delegation)
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{
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set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
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set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
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}
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/**
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* nfs_super_return_all_delegations - return delegations for one superblock
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* @sb: sb to process
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*
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*/
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void nfs_super_return_all_delegations(struct super_block *sb)
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{
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struct nfs_server *server = NFS_SB(sb);
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struct nfs_client *clp = server->nfs_client;
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struct nfs_delegation *delegation;
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if (clp == NULL)
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return;
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
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spin_lock(&delegation->lock);
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set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
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spin_unlock(&delegation->lock);
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}
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rcu_read_unlock();
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if (nfs_client_return_marked_delegations(clp) != 0)
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nfs4_schedule_state_manager(clp);
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}
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static void nfs_mark_return_all_delegation_types(struct nfs_server *server,
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fmode_t flags)
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{
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struct nfs_delegation *delegation;
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list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
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if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
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continue;
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if (delegation->type & flags)
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nfs_mark_return_delegation(server, delegation);
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}
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}
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static void nfs_client_mark_return_all_delegation_types(struct nfs_client *clp,
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fmode_t flags)
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{
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struct nfs_server *server;
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rcu_read_lock();
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list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
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nfs_mark_return_all_delegation_types(server, flags);
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rcu_read_unlock();
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}
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static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
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{
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nfs_client_mark_return_all_delegation_types(clp, FMODE_READ|FMODE_WRITE);
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}
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static void nfs_delegation_run_state_manager(struct nfs_client *clp)
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{
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if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
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nfs4_schedule_state_manager(clp);
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}
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/**
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* nfs_expire_all_delegation_types
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* @clp: client to process
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* @flags: delegation types to expire
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*
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*/
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void nfs_expire_all_delegation_types(struct nfs_client *clp, fmode_t flags)
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{
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nfs_client_mark_return_all_delegation_types(clp, flags);
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nfs_delegation_run_state_manager(clp);
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}
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/**
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* nfs_expire_all_delegations
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* @clp: client to process
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*
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*/
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void nfs_expire_all_delegations(struct nfs_client *clp)
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{
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nfs_expire_all_delegation_types(clp, FMODE_READ|FMODE_WRITE);
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}
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/**
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* nfs_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
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* @clp: client to process
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*
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*/
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void nfs_handle_cb_pathdown(struct nfs_client *clp)
|
|
{
|
|
if (clp == NULL)
|
|
return;
|
|
nfs_client_mark_return_all_delegations(clp);
|
|
}
|
|
|
|
static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
|
|
{
|
|
struct nfs_delegation *delegation;
|
|
|
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
|
|
if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
|
|
continue;
|
|
nfs_mark_return_delegation(server, delegation);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* nfs_expire_unreferenced_delegations - Eliminate unused delegations
|
|
* @clp: nfs_client to process
|
|
*
|
|
*/
|
|
void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
|
|
{
|
|
struct nfs_server *server;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
|
|
nfs_mark_return_unreferenced_delegations(server);
|
|
rcu_read_unlock();
|
|
|
|
nfs_delegation_run_state_manager(clp);
|
|
}
|
|
|
|
/**
|
|
* nfs_async_inode_return_delegation - asynchronously return a delegation
|
|
* @inode: inode to process
|
|
* @stateid: state ID information from CB_RECALL arguments
|
|
*
|
|
* Returns zero on success, or a negative errno value.
|
|
*/
|
|
int nfs_async_inode_return_delegation(struct inode *inode,
|
|
const nfs4_stateid *stateid)
|
|
{
|
|
struct nfs_server *server = NFS_SERVER(inode);
|
|
struct nfs_client *clp = server->nfs_client;
|
|
struct nfs_delegation *delegation;
|
|
|
|
rcu_read_lock();
|
|
delegation = rcu_dereference(NFS_I(inode)->delegation);
|
|
|
|
if (!clp->cl_mvops->validate_stateid(delegation, stateid)) {
|
|
rcu_read_unlock();
|
|
return -ENOENT;
|
|
}
|
|
nfs_mark_return_delegation(server, delegation);
|
|
rcu_read_unlock();
|
|
|
|
nfs_delegation_run_state_manager(clp);
|
|
return 0;
|
|
}
|
|
|
|
static struct inode *
|
|
nfs_delegation_find_inode_server(struct nfs_server *server,
|
|
const struct nfs_fh *fhandle)
|
|
{
|
|
struct nfs_delegation *delegation;
|
|
struct inode *res = NULL;
|
|
|
|
list_for_each_entry_rcu(delegation, &server->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;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* nfs_delegation_find_inode - retrieve the inode associated with a delegation
|
|
* @clp: client state handle
|
|
* @fhandle: filehandle from a delegation recall
|
|
*
|
|
* Returns pointer to inode matching "fhandle," or NULL if a matching inode
|
|
* cannot be found.
|
|
*/
|
|
struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
|
|
const struct nfs_fh *fhandle)
|
|
{
|
|
struct nfs_server *server;
|
|
struct inode *res = NULL;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
|
|
res = nfs_delegation_find_inode_server(server, fhandle);
|
|
if (res != NULL)
|
|
break;
|
|
}
|
|
rcu_read_unlock();
|
|
return res;
|
|
}
|
|
|
|
static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
|
|
{
|
|
struct nfs_delegation *delegation;
|
|
|
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list)
|
|
set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
|
|
}
|
|
|
|
/**
|
|
* nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
|
|
* @clp: nfs_client to process
|
|
*
|
|
*/
|
|
void nfs_delegation_mark_reclaim(struct nfs_client *clp)
|
|
{
|
|
struct nfs_server *server;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
|
|
nfs_delegation_mark_reclaim_server(server);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
|
|
* @clp: nfs_client to process
|
|
*
|
|
*/
|
|
void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
|
|
{
|
|
struct nfs_delegation *delegation;
|
|
struct nfs_server *server;
|
|
struct inode *inode;
|
|
|
|
restart:
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
|
|
list_for_each_entry_rcu(delegation, &server->delegations,
|
|
super_list) {
|
|
if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
|
|
&delegation->flags) == 0)
|
|
continue;
|
|
inode = nfs_delegation_grab_inode(delegation);
|
|
if (inode == NULL)
|
|
continue;
|
|
delegation = nfs_detach_delegation(NFS_I(inode),
|
|
server);
|
|
rcu_read_unlock();
|
|
|
|
if (delegation != NULL)
|
|
nfs_free_delegation(delegation);
|
|
iput(inode);
|
|
goto restart;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* nfs_delegations_present - check for existence of delegations
|
|
* @clp: client state handle
|
|
*
|
|
* Returns one if there are any nfs_delegation structures attached
|
|
* to this nfs_client.
|
|
*/
|
|
int nfs_delegations_present(struct nfs_client *clp)
|
|
{
|
|
struct nfs_server *server;
|
|
int ret = 0;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
|
|
if (!list_empty(&server->delegations)) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* nfs4_copy_delegation_stateid - Copy inode's state ID information
|
|
* @dst: stateid data structure to fill in
|
|
* @inode: inode to check
|
|
*
|
|
* Returns one and fills in "dst->data" * if inode had a delegation,
|
|
* otherwise zero is returned.
|
|
*/
|
|
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;
|
|
}
|