cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fscache.h (4389B)

      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/* NFS filesystem cache interface definitions
      3 *
      4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
      5 * Written by David Howells (dhowells@redhat.com)
      6 */
      7
      8#ifndef _NFS_FSCACHE_H
      9#define _NFS_FSCACHE_H
     10
     11#include <linux/swap.h>
     12#include <linux/nfs_fs.h>
     13#include <linux/nfs_mount.h>
     14#include <linux/nfs4_mount.h>
     15#include <linux/fscache.h>
     16#include <linux/iversion.h>
     17
     18#ifdef CONFIG_NFS_FSCACHE
     19
     20/*
     21 * Definition of the auxiliary data attached to NFS inode storage objects
     22 * within the cache.
     23 *
     24 * The contents of this struct are recorded in the on-disk local cache in the
     25 * auxiliary data attached to the data storage object backing an inode.  This
     26 * permits coherency to be managed when a new inode binds to an already extant
     27 * cache object.
     28 */
     29struct nfs_fscache_inode_auxdata {
     30	s64	mtime_sec;
     31	s64	mtime_nsec;
     32	s64	ctime_sec;
     33	s64	ctime_nsec;
     34	u64	change_attr;
     35};
     36
     37/*
     38 * fscache.c
     39 */
     40extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
     41extern void nfs_fscache_release_super_cookie(struct super_block *);
     42
     43extern void nfs_fscache_init_inode(struct inode *);
     44extern void nfs_fscache_clear_inode(struct inode *);
     45extern void nfs_fscache_open_file(struct inode *, struct file *);
     46extern void nfs_fscache_release_file(struct inode *, struct file *);
     47
     48extern int __nfs_fscache_read_page(struct inode *, struct page *);
     49extern void __nfs_fscache_write_page(struct inode *, struct page *);
     50
     51static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
     52{
     53	if (folio_test_fscache(folio)) {
     54		if (current_is_kswapd() || !(gfp & __GFP_FS))
     55			return false;
     56		folio_wait_fscache(folio);
     57		fscache_note_page_release(nfs_i_fscache(folio->mapping->host));
     58		nfs_inc_fscache_stats(folio->mapping->host,
     59				      NFSIOS_FSCACHE_PAGES_UNCACHED);
     60	}
     61	return true;
     62}
     63
     64/*
     65 * Retrieve a page from an inode data storage object.
     66 */
     67static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
     68{
     69	if (nfs_i_fscache(inode))
     70		return __nfs_fscache_read_page(inode, page);
     71	return -ENOBUFS;
     72}
     73
     74/*
     75 * Store a page newly fetched from the server in an inode data storage object
     76 * in the cache.
     77 */
     78static inline void nfs_fscache_write_page(struct inode *inode,
     79					   struct page *page)
     80{
     81	if (nfs_i_fscache(inode))
     82		__nfs_fscache_write_page(inode, page);
     83}
     84
     85static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
     86					      struct inode *inode)
     87{
     88	memset(auxdata, 0, sizeof(*auxdata));
     89	auxdata->mtime_sec  = inode->i_mtime.tv_sec;
     90	auxdata->mtime_nsec = inode->i_mtime.tv_nsec;
     91	auxdata->ctime_sec  = inode->i_ctime.tv_sec;
     92	auxdata->ctime_nsec = inode->i_ctime.tv_nsec;
     93
     94	if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4)
     95		auxdata->change_attr = inode_peek_iversion_raw(inode);
     96}
     97
     98/*
     99 * Invalidate the contents of fscache for this inode.  This will not sleep.
    100 */
    101static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
    102{
    103	struct nfs_fscache_inode_auxdata auxdata;
    104	struct nfs_inode *nfsi = NFS_I(inode);
    105
    106	if (nfsi->fscache) {
    107		nfs_fscache_update_auxdata(&auxdata, inode);
    108		fscache_invalidate(nfsi->fscache, &auxdata,
    109				   i_size_read(inode), flags);
    110	}
    111}
    112
    113/*
    114 * indicate the client caching state as readable text
    115 */
    116static inline const char *nfs_server_fscache_state(struct nfs_server *server)
    117{
    118	if (server->fscache)
    119		return "yes";
    120	return "no ";
    121}
    122
    123#else /* CONFIG_NFS_FSCACHE */
    124static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
    125
    126static inline void nfs_fscache_init_inode(struct inode *inode) {}
    127static inline void nfs_fscache_clear_inode(struct inode *inode) {}
    128static inline void nfs_fscache_open_file(struct inode *inode,
    129					 struct file *filp) {}
    130static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
    131
    132static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
    133{
    134	return true; /* may release folio */
    135}
    136static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
    137{
    138	return -ENOBUFS;
    139}
    140static inline void nfs_fscache_write_page(struct inode *inode, struct page *page) {}
    141static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
    142
    143static inline const char *nfs_server_fscache_state(struct nfs_server *server)
    144{
    145	return "no ";
    146}
    147
    148#endif /* CONFIG_NFS_FSCACHE */
    149#endif /* _NFS_FSCACHE_H */