/* SPDX-License-Identifier: GPL-2.0-or-later */ /* NFS filesystem cache interface definitions * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #ifndef _NFS_FSCACHE_H #define _NFS_FSCACHE_H #include #include #include #include #include #include #ifdef CONFIG_NFS_FSCACHE /* * Definition of the auxiliary data attached to NFS inode storage objects * within the cache. * * The contents of this struct are recorded in the on-disk local cache in the * auxiliary data attached to the data storage object backing an inode. This * permits coherency to be managed when a new inode binds to an already extant * cache object. */ struct nfs_fscache_inode_auxdata { s64 mtime_sec; s64 mtime_nsec; s64 ctime_sec; s64 ctime_nsec; u64 change_attr; }; struct nfs_netfs_io_data { /* * NFS may split a netfs_io_subrequest into multiple RPCs, each * with their own read completion. In netfs, we can only call * netfs_subreq_terminated() once for each subrequest. Use the * refcount here to double as a marker of the last RPC completion, * and only call netfs via netfs_subreq_terminated() once. */ refcount_t refcount; struct netfs_io_subrequest *sreq; /* * Final disposition of the netfs_io_subrequest, sent in * netfs_subreq_terminated() */ atomic64_t transferred; int error; }; static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs) { refcount_inc(&netfs->refcount); } static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs) { ssize_t final_len; /* Only the last RPC completion should call netfs_subreq_terminated() */ if (!refcount_dec_and_test(&netfs->refcount)) return; /* * The NFS pageio interface may read a complete page, even when netfs * only asked for a partial page. Specifically, this may be seen when * one thread is truncating a file while another one is reading the last * page of the file. * Correct the final length here to be no larger than the netfs subrequest * length, and thus avoid netfs's "Subreq overread" warning message. */ final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred)); netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false); kfree(netfs); } static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) { netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops); } extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr); extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr); extern int nfs_netfs_folio_unlock(struct folio *folio); /* * fscache.c */ extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int); extern void nfs_fscache_release_super_cookie(struct super_block *); extern void nfs_fscache_init_inode(struct inode *); extern void nfs_fscache_clear_inode(struct inode *); extern void nfs_fscache_open_file(struct inode *, struct file *); extern void nfs_fscache_release_file(struct inode *, struct file *); extern int nfs_netfs_readahead(struct readahead_control *ractl); extern int nfs_netfs_read_folio(struct file *file, struct folio *folio); static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) { if (folio_test_fscache(folio)) { if (current_is_kswapd() || !(gfp & __GFP_FS)) return false; folio_wait_fscache(folio); } fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host))); return true; } static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata, struct inode *inode) { memset(auxdata, 0, sizeof(*auxdata)); auxdata->mtime_sec = inode_get_mtime(inode).tv_sec; auxdata->mtime_nsec = inode_get_mtime(inode).tv_nsec; auxdata->ctime_sec = inode_get_ctime(inode).tv_sec; auxdata->ctime_nsec = inode_get_ctime(inode).tv_nsec; if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4) auxdata->change_attr = inode_peek_iversion_raw(inode); } /* * Invalidate the contents of fscache for this inode. This will not sleep. */ static inline void nfs_fscache_invalidate(struct inode *inode, int flags) { struct nfs_fscache_inode_auxdata auxdata; struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs); nfs_fscache_update_auxdata(&auxdata, inode); fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags); } /* * indicate the client caching state as readable text */ static inline const char *nfs_server_fscache_state(struct nfs_server *server) { if (server->fscache) return "yes"; return "no "; } static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr, struct nfs_pageio_descriptor *desc) { hdr->netfs = desc->pg_netfs; } static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { desc->pg_netfs = hdr->netfs; } static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) { desc->pg_netfs = NULL; } #else /* CONFIG_NFS_FSCACHE */ static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {} static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {} static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {} static inline int nfs_netfs_folio_unlock(struct folio *folio) { return 1; } static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} static inline void nfs_fscache_init_inode(struct inode *inode) {} static inline void nfs_fscache_clear_inode(struct inode *inode) {} static inline void nfs_fscache_open_file(struct inode *inode, struct file *filp) {} static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {} static inline int nfs_netfs_readahead(struct readahead_control *ractl) { return -ENOBUFS; } static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio) { return -ENOBUFS; } static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) { return true; /* may release folio */ } static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {} static inline const char *nfs_server_fscache_state(struct nfs_server *server) { return "no "; } static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr, struct nfs_pageio_descriptor *desc) {} static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) {} static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {} #endif /* CONFIG_NFS_FSCACHE */ #endif /* _NFS_FSCACHE_H */