520 lines
13 KiB
C
520 lines
13 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/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_do_free_delegation(struct nfs_delegation *delegation)
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{
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kfree(delegation);
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}
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static void nfs_free_delegation_callback(struct rcu_head *head)
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{
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struct nfs_delegation *delegation = container_of(head, struct nfs_delegation, rcu);
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nfs_do_free_delegation(delegation);
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}
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static void nfs_free_delegation(struct nfs_delegation *delegation)
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{
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struct rpc_cred *cred;
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cred = rcu_dereference(delegation->cred);
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rcu_assign_pointer(delegation->cred, NULL);
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call_rcu(&delegation->rcu, nfs_free_delegation_callback);
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if (cred)
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put_rpccred(cred);
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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;
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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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status = nfs4_lock_delegation_recall(state, fl);
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if (status >= 0)
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continue;
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switch (status) {
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default:
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printk(KERN_ERR "%s: unhandled error %d.\n",
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__FUNCTION__, status);
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case -NFS4ERR_EXPIRED:
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/* kill_proc(fl->fl_pid, SIGLOST, 1); */
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case -NFS4ERR_STALE_CLIENTID:
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nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
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goto out_err;
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}
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}
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return 0;
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out_err:
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return status;
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}
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static void 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;
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goto again;
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}
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spin_unlock(&inode->i_lock);
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}
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/*
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* Set up a delegation on an inode
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*/
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void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
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{
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struct nfs_delegation *delegation = NFS_I(inode)->delegation;
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struct rpc_cred *oldcred;
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if (delegation == NULL)
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return;
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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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delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
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NFS_I(inode)->delegation_state = delegation->type;
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smp_wmb();
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put_rpccred(oldcred);
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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 nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
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{
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struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
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if (delegation == NULL)
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goto nomatch;
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if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
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sizeof(delegation->stateid.data)) != 0)
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goto nomatch;
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list_del_rcu(&delegation->super_list);
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nfsi->delegation_state = 0;
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rcu_assign_pointer(nfsi->delegation, NULL);
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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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/*
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* Set up a delegation on an inode
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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_client *clp = NFS_SERVER(inode)->nfs_client;
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_delegation *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_KERNEL);
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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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spin_lock(&clp->cl_lock);
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if (rcu_dereference(nfsi->delegation) != NULL) {
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if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
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sizeof(delegation->stateid)) == 0 &&
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delegation->type == nfsi->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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__FUNCTION__, clp->cl_hostname);
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if (delegation->type <= nfsi->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, NULL);
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}
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list_add_rcu(&delegation->super_list, &clp->cl_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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/* Sync all data to disk upon delegation return */
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static void nfs_msync_inode(struct inode *inode)
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{
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filemap_fdatawrite(inode->i_mapping);
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nfs_wb_all(inode);
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filemap_fdatawait(inode->i_mapping);
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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)
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{
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struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
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struct nfs_inode *nfsi = NFS_I(inode);
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nfs_msync_inode(inode);
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down_read(&clp->cl_sem);
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/* Guard against new delegated open calls */
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down_write(&nfsi->rwsem);
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nfs_delegation_claim_opens(inode, &delegation->stateid);
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up_write(&nfsi->rwsem);
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up_read(&clp->cl_sem);
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nfs_msync_inode(inode);
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return nfs_do_return_delegation(inode, delegation, 1);
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}
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/*
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* This function returns the delegation without reclaiming opens
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* or protecting against delegation reclaims.
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* It is therefore really only safe to be called from
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* 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_client *clp = NFS_SERVER(inode)->nfs_client;
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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_dereference(nfsi->delegation) != NULL) {
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(nfsi, NULL);
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spin_unlock(&clp->cl_lock);
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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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int nfs_inode_return_delegation(struct inode *inode)
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{
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struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
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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_dereference(nfsi->delegation) != NULL) {
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(nfsi, NULL);
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spin_unlock(&clp->cl_lock);
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if (delegation != NULL)
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err = __nfs_inode_return_delegation(inode, delegation);
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}
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return err;
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}
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/*
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* Return all delegations associated to a super block
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*/
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void nfs_return_all_delegations(struct super_block *sb)
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{
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struct nfs_client *clp = NFS_SB(sb)->nfs_client;
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struct nfs_delegation *delegation;
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struct inode *inode;
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if (clp == NULL)
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return;
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restart:
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
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if (delegation->inode->i_sb != sb)
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continue;
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inode = igrab(delegation->inode);
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if (inode == NULL)
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continue;
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
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spin_unlock(&clp->cl_lock);
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rcu_read_unlock();
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if (delegation != NULL)
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__nfs_inode_return_delegation(inode, delegation);
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iput(inode);
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goto restart;
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}
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rcu_read_unlock();
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}
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static int nfs_do_expire_all_delegations(void *ptr)
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{
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struct nfs_client *clp = ptr;
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struct nfs_delegation *delegation;
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struct inode *inode;
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allow_signal(SIGKILL);
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restart:
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if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
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goto out;
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if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
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goto out;
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
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inode = igrab(delegation->inode);
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if (inode == NULL)
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continue;
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
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spin_unlock(&clp->cl_lock);
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rcu_read_unlock();
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if (delegation)
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__nfs_inode_return_delegation(inode, delegation);
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iput(inode);
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goto restart;
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}
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rcu_read_unlock();
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out:
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nfs_put_client(clp);
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module_put_and_exit(0);
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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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struct task_struct *task;
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__module_get(THIS_MODULE);
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atomic_inc(&clp->cl_count);
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task = kthread_run(nfs_do_expire_all_delegations, clp,
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"%s-delegreturn",
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rpc_peeraddr2str(clp->cl_rpcclient,
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RPC_DISPLAY_ADDR));
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if (!IS_ERR(task))
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return;
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nfs_put_client(clp);
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module_put(THIS_MODULE);
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}
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/*
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* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
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*/
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void nfs_handle_cb_pathdown(struct nfs_client *clp)
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{
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struct nfs_delegation *delegation;
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struct inode *inode;
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if (clp == NULL)
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return;
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restart:
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
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inode = igrab(delegation->inode);
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if (inode == NULL)
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continue;
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
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spin_unlock(&clp->cl_lock);
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rcu_read_unlock();
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if (delegation != NULL)
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__nfs_inode_return_delegation(inode, delegation);
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iput(inode);
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goto restart;
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}
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rcu_read_unlock();
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}
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struct recall_threadargs {
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struct inode *inode;
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struct nfs_client *clp;
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const nfs4_stateid *stateid;
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struct completion started;
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int result;
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};
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static int recall_thread(void *data)
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{
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struct recall_threadargs *args = (struct recall_threadargs *)data;
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struct inode *inode = igrab(args->inode);
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struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs_delegation *delegation;
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daemonize("nfsv4-delegreturn");
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nfs_msync_inode(inode);
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down_read(&clp->cl_sem);
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down_write(&nfsi->rwsem);
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spin_lock(&clp->cl_lock);
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delegation = nfs_detach_delegation_locked(nfsi, args->stateid);
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if (delegation != NULL)
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args->result = 0;
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else
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args->result = -ENOENT;
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spin_unlock(&clp->cl_lock);
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complete(&args->started);
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nfs_delegation_claim_opens(inode, args->stateid);
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up_write(&nfsi->rwsem);
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up_read(&clp->cl_sem);
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nfs_msync_inode(inode);
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if (delegation != NULL)
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nfs_do_return_delegation(inode, delegation, 1);
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iput(inode);
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module_put_and_exit(0);
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}
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/*
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* Asynchronous delegation recall!
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*/
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int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
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{
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struct recall_threadargs data = {
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.inode = inode,
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.stateid = stateid,
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};
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int status;
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init_completion(&data.started);
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__module_get(THIS_MODULE);
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status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
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if (status < 0)
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goto out_module_put;
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wait_for_completion(&data.started);
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return data.result;
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out_module_put:
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module_put(THIS_MODULE);
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return status;
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}
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/*
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* Retrieve the inode associated with a delegation
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*/
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struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
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{
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struct nfs_delegation *delegation;
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struct inode *res = NULL;
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
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if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
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res = igrab(delegation->inode);
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break;
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}
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}
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rcu_read_unlock();
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return res;
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}
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/*
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* Mark all delegations as needing to be reclaimed
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*/
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void nfs_delegation_mark_reclaim(struct nfs_client *clp)
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{
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struct nfs_delegation *delegation;
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rcu_read_lock();
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list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list)
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delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
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rcu_read_unlock();
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}
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/*
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* Reap all unclaimed delegations after reboot recovery is done
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*/
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void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
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{
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struct nfs_delegation *delegation;
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restart:
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rcu_read_lock();
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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;
|
|
}
|