--- /dev/null
+/*
+ * linux/fs/nfs/delegation.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFS file delegation management
+ *
+ */
+#include <linux/config.h>
+#include <linux/completion.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_xdr.h>
+
+#include "delegation.h"
+
+static struct nfs_delegation *nfs_alloc_delegation(void)
+{
+ return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
+}
+
+static void nfs_free_delegation(struct nfs_delegation *delegation)
+{
+ if (delegation->cred)
+ put_rpccred(delegation->cred);
+ kfree(delegation);
+}
+
+static void nfs_delegation_claim_opens(struct inode *inode)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_open_context *ctx;
+ struct nfs4_state *state;
+
+again:
+ spin_lock(&inode->i_lock);
+ list_for_each_entry(ctx, &nfsi->open_files, list) {
+ state = ctx->state;
+ if (state == NULL)
+ continue;
+ if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
+ continue;
+ get_nfs_open_context(ctx);
+ spin_unlock(&inode->i_lock);
+ if (nfs4_open_delegation_recall(ctx->dentry, state) < 0)
+ return;
+ put_nfs_open_context(ctx);
+ goto again;
+ }
+ spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Set up a delegation on an inode
+ */
+void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
+{
+ struct nfs_delegation *delegation = NFS_I(inode)->delegation;
+
+ if (delegation == NULL)
+ return;
+ memcpy(delegation->stateid.data, res->delegation.data,
+ sizeof(delegation->stateid.data));
+ delegation->type = res->delegation_type;
+ delegation->maxsize = res->maxsize;
+ put_rpccred(cred);
+ delegation->cred = get_rpccred(cred);
+ delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
+ NFS_I(inode)->delegation_state = delegation->type;
+ smp_wmb();
+}
+
+/*
+ * Set up a delegation on an inode
+ */
+int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
+{
+ struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_delegation *delegation;
+ int status = 0;
+
+ delegation = nfs_alloc_delegation();
+ if (delegation == NULL)
+ return -ENOMEM;
+ memcpy(delegation->stateid.data, res->delegation.data,
+ sizeof(delegation->stateid.data));
+ delegation->type = res->delegation_type;
+ delegation->maxsize = res->maxsize;
+ delegation->cred = get_rpccred(cred);
+ delegation->inode = inode;
+
+ spin_lock(&clp->cl_lock);
+ if (nfsi->delegation == NULL) {
+ list_add(&delegation->super_list, &clp->cl_delegations);
+ nfsi->delegation = delegation;
+ nfsi->delegation_state = delegation->type;
+ delegation = NULL;
+ } else {
+ if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
+ sizeof(delegation->stateid)) != 0 ||
+ delegation->type != nfsi->delegation->type) {
+ printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
+ __FUNCTION__, NIPQUAD(clp->cl_addr));
+ status = -EIO;
+ }
+ }
+ spin_unlock(&clp->cl_lock);
+ if (delegation != NULL)
+ kfree(delegation);
+ return status;
+}
+
+static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
+{
+ int res = 0;
+
+ __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+
+ res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
+ nfs_free_delegation(delegation);
+ return res;
+}
+
+/* Sync all data to disk upon delegation return */
+static void nfs_msync_inode(struct inode *inode)
+{
+ filemap_fdatawrite(inode->i_mapping);
+ nfs_wb_all(inode);
+ filemap_fdatawait(inode->i_mapping);
+}
+
+/*
+ * Basic procedure for returning a delegation to the server
+ */
+int nfs_inode_return_delegation(struct inode *inode)
+{
+ struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_delegation *delegation;
+ int res = 0;
+
+ nfs_msync_inode(inode);
+ down_read(&clp->cl_sem);
+ /* Guard against new delegated open calls */
+ down_write(&nfsi->rwsem);
+ spin_lock(&clp->cl_lock);
+ delegation = nfsi->delegation;
+ if (delegation != NULL) {
+ list_del_init(&delegation->super_list);
+ nfsi->delegation = NULL;
+ nfsi->delegation_state = 0;
+ }
+ spin_unlock(&clp->cl_lock);
+ nfs_delegation_claim_opens(inode);
+ up_write(&nfsi->rwsem);
+ up_read(&clp->cl_sem);
+ nfs_msync_inode(inode);
+
+ if (delegation != NULL)
+ res = nfs_do_return_delegation(inode, delegation);
+ return res;
+}
+
+/*
+ * Return all delegations associated to a super block
+ */
+void nfs_return_all_delegations(struct super_block *sb)
+{
+ struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
+ struct nfs_delegation *delegation;
+ struct inode *inode;
+
+ if (clp == NULL)
+ return;
+restart:
+ spin_lock(&clp->cl_lock);
+ list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
+ if (delegation->inode->i_sb != sb)
+ continue;
+ inode = igrab(delegation->inode);
+ if (inode == NULL)
+ continue;
+ spin_unlock(&clp->cl_lock);
+ nfs_inode_return_delegation(inode);
+ iput(inode);
+ goto restart;
+ }
+ spin_unlock(&clp->cl_lock);
+}
+
+/*
+ * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
+ */
+void nfs_handle_cb_pathdown(struct nfs4_client *clp)
+{
+ struct nfs_delegation *delegation;
+ struct inode *inode;
+
+ if (clp == NULL)
+ return;
+restart:
+ spin_lock(&clp->cl_lock);
+ list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
+ inode = igrab(delegation->inode);
+ if (inode == NULL)
+ continue;
+ spin_unlock(&clp->cl_lock);
+ nfs_inode_return_delegation(inode);
+ iput(inode);
+ goto restart;
+ }
+ spin_unlock(&clp->cl_lock);
+}
+
+struct recall_threadargs {
+ struct inode *inode;
+ struct nfs4_client *clp;
+ const nfs4_stateid *stateid;
+
+ struct completion started;
+ int result;
+};
+
+static int recall_thread(void *data)
+{
+ struct recall_threadargs *args = (struct recall_threadargs *)data;
+ struct inode *inode = igrab(args->inode);
+ struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_delegation *delegation;
+
+ daemonize("nfsv4-delegreturn");
+
+ nfs_msync_inode(inode);
+ down_read(&clp->cl_sem);
+ down_write(&nfsi->rwsem);
+ spin_lock(&clp->cl_lock);
+ delegation = nfsi->delegation;
+ if (delegation != NULL && memcmp(delegation->stateid.data,
+ args->stateid->data,
+ sizeof(delegation->stateid.data)) == 0) {
+ list_del_init(&delegation->super_list);
+ nfsi->delegation = NULL;
+ nfsi->delegation_state = 0;
+ args->result = 0;
+ } else {
+ delegation = NULL;
+ args->result = -ENOENT;
+ }
+ spin_unlock(&clp->cl_lock);
+ complete(&args->started);
+ nfs_delegation_claim_opens(inode);
+ up_write(&nfsi->rwsem);
+ up_read(&clp->cl_sem);
+ nfs_msync_inode(inode);
+
+ if (delegation != NULL)
+ nfs_do_return_delegation(inode, delegation);
+ iput(inode);
+ module_put_and_exit(0);
+}
+
+/*
+ * Asynchronous delegation recall!
+ */
+int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
+{
+ struct recall_threadargs data = {
+ .inode = inode,
+ .stateid = stateid,
+ };
+ int status;
+
+ init_completion(&data.started);
+ __module_get(THIS_MODULE);
+ status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
+ if (status < 0)
+ goto out_module_put;
+ wait_for_completion(&data.started);
+ return data.result;
+out_module_put:
+ module_put(THIS_MODULE);
+ return status;
+}
+
+/*
+ * Retrieve the inode associated with a delegation
+ */
+struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle)
+{
+ struct nfs_delegation *delegation;
+ struct inode *res = NULL;
+ spin_lock(&clp->cl_lock);
+ list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
+ if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
+ res = igrab(delegation->inode);
+ break;
+ }
+ }
+ spin_unlock(&clp->cl_lock);
+ return res;
+}
+
+/*
+ * Mark all delegations as needing to be reclaimed
+ */
+void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
+{
+ struct nfs_delegation *delegation;
+ spin_lock(&clp->cl_lock);
+ list_for_each_entry(delegation, &clp->cl_delegations, super_list)
+ delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
+ spin_unlock(&clp->cl_lock);
+}
+
+/*
+ * Reap all unclaimed delegations after reboot recovery is done
+ */
+void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
+{
+ struct nfs_delegation *delegation, *n;
+ LIST_HEAD(head);
+ spin_lock(&clp->cl_lock);
+ list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
+ if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
+ continue;
+ list_move(&delegation->super_list, &head);
+ NFS_I(delegation->inode)->delegation = NULL;
+ NFS_I(delegation->inode)->delegation_state = 0;
+ }
+ spin_unlock(&clp->cl_lock);
+ while(!list_empty(&head)) {
+ delegation = list_entry(head.next, struct nfs_delegation, super_list);
+ list_del(&delegation->super_list);
+ nfs_free_delegation(delegation);
+ }
+}
git://git.onelab.eu / linux-2.6.git / blobdiff