linux/fs/nfs/delegation.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/slab.h>
#include <linux/spinlock.h>
#include <linux/iversion.h>

#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>

#include "nfs4_fs.h"
#include "nfs4session.h"
#include "delegation.h"
#include "internal.h"
#include "nfs4trace.h"

#define NFS_DEFAULT_DELEGATION_WATERMARK …

static atomic_long_t nfs_active_delegations;
static unsigned nfs_delegation_watermark = …;

static void __nfs_free_delegation(struct nfs_delegation *delegation)
{ … }

static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
{ … }

static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation)
{ … }

static void nfs_put_delegation(struct nfs_delegation *delegation)
{ … }

static void nfs_free_delegation(struct nfs_delegation *delegation)
{ … }

/**
 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
 * @delegation: delegation to process
 *
 */
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
{ … }

static void nfs_mark_return_delegation(struct nfs_server *server,
				       struct nfs_delegation *delegation)
{ … }

static bool nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
				     fmode_t type)
{ … }

struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
{ … }

static int nfs4_do_check_delegation(struct inode *inode, fmode_t type,
				    int flags, bool mark)
{ … }
/**
 * nfs4_have_delegation - check if inode has a delegation, mark it
 * NFS_DELEGATION_REFERENCED if there is one.
 * @inode: inode to check
 * @type: delegation types to check for
 * @flags: various modifiers
 *
 * Returns one if inode has the indicated delegation, otherwise zero.
 */
int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags)
{ … }

/*
 * nfs4_check_delegation - check if inode has a delegation, do not mark
 * NFS_DELEGATION_REFERENCED if it has one.
 */
int nfs4_check_delegation(struct inode *inode, fmode_t type)
{ … }

static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
{ … }

static int nfs_delegation_claim_opens(struct inode *inode,
		const nfs4_stateid *stateid, fmode_t type)
{ … }

/**
 * nfs_inode_reclaim_delegation - process a delegation reclaim request
 * @inode: inode to process
 * @cred: credential to use for request
 * @type: delegation type
 * @stateid: delegation stateid
 * @pagemod_limit: write delegation "space_limit"
 * @deleg_type: raw delegation type
 *
 */
void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
				  fmode_t type, const nfs4_stateid *stateid,
				  unsigned long pagemod_limit, u32 deleg_type)
{ … }

static int nfs_do_return_delegation(struct inode *inode,
				    struct nfs_delegation *delegation,
				    int issync)
{ … }

static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
{ … }

static struct nfs_delegation *
nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
{ … }

static struct nfs_delegation *
nfs_start_delegation_return(struct nfs_inode *nfsi)
{ … }

static void nfs_abort_delegation_return(struct nfs_delegation *delegation,
					struct nfs_client *clp, int err)
{ … }

static struct nfs_delegation *
nfs_detach_delegation_locked(struct nfs_inode *nfsi,
		struct nfs_delegation *delegation,
		struct nfs_client *clp)
{ … }

static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
		struct nfs_delegation *delegation,
		struct nfs_server *server)
{ … }

static struct nfs_delegation *
nfs_inode_detach_delegation(struct inode *inode)
{ … }

static void
nfs_update_delegation_cred(struct nfs_delegation *delegation,
		const struct cred *cred)
{ … }

static void
nfs_update_inplace_delegation(struct nfs_delegation *delegation,
		const struct nfs_delegation *update)
{ … }

/**
 * nfs_inode_set_delegation - set up a delegation on an inode
 * @inode: inode to which delegation applies
 * @cred: cred to use for subsequent delegation processing
 * @type: delegation type
 * @stateid: delegation stateid
 * @pagemod_limit: write delegation "space_limit"
 * @deleg_type: raw delegation type
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
			     fmode_t type, const nfs4_stateid *stateid,
			     unsigned long pagemod_limit, u32 deleg_type)
{ … }

/*
 * Basic procedure for returning a delegation to the server
 */
static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
{ … }

static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
{ … }

static int nfs_server_return_marked_delegations(struct nfs_server *server,
		void __always_unused *data)
{ … }

static bool nfs_server_clear_delayed_delegations(struct nfs_server *server)
{ … }

static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp)
{ … }

/**
 * nfs_client_return_marked_delegations - return previously marked delegations
 * @clp: nfs_client to process
 *
 * Note that this function is designed to be called by the state
 * manager thread. For this reason, it cannot flush the dirty data,
 * since that could deadlock in case of a state recovery error.
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_client_return_marked_delegations(struct nfs_client *clp)
{ … }

/**
 * nfs_inode_evict_delegation - return delegation, don't reclaim opens
 * @inode: inode to process
 *
 * Does not protect against delegation reclaims, therefore really only safe
 * to be called from nfs4_clear_inode(). Guaranteed to always free
 * the delegation structure.
 */
void nfs_inode_evict_delegation(struct inode *inode)
{ … }

/**
 * nfs4_inode_return_delegation - synchronously return a delegation
 * @inode: inode to process
 *
 * This routine will always flush any dirty data to disk on the
 * assumption that if we need to return the delegation, then
 * we should stop caching.
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs4_inode_return_delegation(struct inode *inode)
{ … }

/**
 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation
 * @inode: inode to process
 *
 * This routine is called on file close in order to determine if the
 * inode delegation needs to be returned immediately.
 */
void nfs4_inode_return_delegation_on_close(struct inode *inode)
{ … }

/**
 * nfs4_inode_make_writeable
 * @inode: pointer to inode
 *
 * Make the inode writeable by returning the delegation if necessary
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs4_inode_make_writeable(struct inode *inode)
{ … }

static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
		struct nfs_delegation *delegation)
{ … }

static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
{ … }

static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
{ … }

static void nfs_delegation_run_state_manager(struct nfs_client *clp)
{ … }

/**
 * nfs_expire_all_delegations
 * @clp: client to process
 *
 */
void nfs_expire_all_delegations(struct nfs_client *clp)
{ … }

/**
 * nfs_server_return_all_delegations - return delegations for one superblock
 * @server: pointer to nfs_server to process
 *
 */
void nfs_server_return_all_delegations(struct nfs_server *server)
{ … }

static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
						 fmode_t flags)
{ … }

static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
							fmode_t flags)
{ … }

static void nfs_revoke_delegation(struct inode *inode,
		const nfs4_stateid *stateid)
{ … }

void nfs_remove_bad_delegation(struct inode *inode,
		const nfs4_stateid *stateid)
{ … }
EXPORT_SYMBOL_GPL(…);

void nfs_delegation_mark_returned(struct inode *inode,
		const nfs4_stateid *stateid)
{ … }

/**
 * nfs_expire_unused_delegation_types
 * @clp: client to process
 * @flags: delegation types to expire
 *
 */
void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
{ … }

static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
{ … }

/**
 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
 * @clp: nfs_client to process
 *
 */
void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
{ … }

/**
 * nfs_async_inode_return_delegation - asynchronously return a delegation
 * @inode: inode to process
 * @stateid: state ID information
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_async_inode_return_delegation(struct inode *inode,
				      const nfs4_stateid *stateid)
{ … }

static struct inode *
nfs_delegation_find_inode_server(struct nfs_server *server,
				 const struct nfs_fh *fhandle)
{ … }

/**
 * 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)
{ … }

static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
{ … }

/**
 * 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)
{ … }

static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
		void __always_unused *data)
{ … }

/**
 * 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)
{ … }

static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
{ … }

static void nfs_mark_test_expired_delegation(struct nfs_server *server,
	    struct nfs_delegation *delegation)
{ … }

static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
		struct inode *inode)
{ … }

static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
{ … }

/**
 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
 * @clp: nfs_client to process
 *
 * Iterates through all the delegations associated with this server and
 * marks them as needing to be checked for validity.
 */
void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
{ … }

/**
 * nfs_test_expired_all_delegations - test all delegations for a client
 * @clp: nfs_client to process
 *
 * Helper for handling "recallable state revoked" status from server.
 */
void nfs_test_expired_all_delegations(struct nfs_client *clp)
{ … }

static void
nfs_delegation_test_free_expired(struct inode *inode,
		nfs4_stateid *stateid,
		const struct cred *cred)
{ … }

static int nfs_server_reap_expired_delegations(struct nfs_server *server,
		void __always_unused *data)
{ … }

/**
 * nfs_reap_expired_delegations - reap expired delegations
 * @clp: nfs_client to process
 *
 * Iterates through all the delegations associated with this server and
 * checks if they have may have been revoked. This function is usually
 * expected to be called in cases where the server may have lost its
 * lease.
 */
void nfs_reap_expired_delegations(struct nfs_client *clp)
{ … }

void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
		const nfs4_stateid *stateid)
{ … }

/**
 * 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)
{ … }

/**
 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
 * @dst: stateid to refresh
 * @inode: inode to check
 *
 * Returns "true" and updates "dst->seqid" * if inode had a delegation
 * that matches our delegation stateid. Otherwise "false" is returned.
 */
bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
{ … }

/**
 * nfs4_copy_delegation_stateid - Copy inode's state ID information
 * @inode: inode to check
 * @flags: delegation type requirement
 * @dst: stateid data structure to fill in
 * @cred: optional argument to retrieve credential
 *
 * Returns "true" and fills in "dst->data" * if inode had a delegation,
 * otherwise "false" is returned.
 */
bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
		nfs4_stateid *dst, const struct cred **cred)
{ … }

/**
 * nfs4_delegation_flush_on_close - Check if we must flush file on close
 * @inode: inode to check
 *
 * This function checks the number of outstanding writes to the file
 * against the delegation 'space_limit' field to see if
 * the spec requires us to flush the file on close.
 */
bool nfs4_delegation_flush_on_close(const struct inode *inode)
{ … }

module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);