| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Trond Myklebust | 8599 | 56.78% | 251 | 45.31% |
| Anna Schumaker | 1798 | 11.87% | 18 | 3.25% |
| Linus Torvalds (pre-git) | 1623 | 10.72% | 79 | 14.26% |
| Neil Brown | 790 | 5.22% | 18 | 3.25% |
| Al Viro | 526 | 3.47% | 45 | 8.12% |
| Chuck Lever | 299 | 1.97% | 16 | 2.89% |
| Miklos Szeredi | 189 | 1.25% | 11 | 1.99% |
| Jeff Layton | 175 | 1.16% | 7 | 1.26% |
| Benjamin Coddington | 148 | 0.98% | 6 | 1.08% |
| Andreas Gruenbacher | 121 | 0.80% | 3 | 0.54% |
| Linus Torvalds | 119 | 0.79% | 13 | 2.35% |
| David Howells | 92 | 0.61% | 7 | 1.26% |
| Weston Andros Adamson | 79 | 0.52% | 2 | 0.36% |
| Olivier Galibert | 58 | 0.38% | 1 | 0.18% |
| Suresh Jayaraman | 57 | 0.38% | 1 | 0.18% |
| David P. Quigley | 43 | 0.28% | 3 | 0.54% |
| Olga Kornievskaia | 35 | 0.23% | 1 | 0.18% |
| Christian Brauner | 33 | 0.22% | 8 | 1.44% |
| Matthew Wilcox | 32 | 0.21% | 2 | 0.36% |
| Chengen Du | 30 | 0.20% | 2 | 0.36% |
| Andrew Morton | 25 | 0.17% | 3 | 0.54% |
| van der Linden, Frank | 23 | 0.15% | 2 | 0.36% |
| David Chinner | 22 | 0.15% | 2 | 0.36% |
| Kinglong Mee | 20 | 0.13% | 1 | 0.18% |
| Art Haas | 17 | 0.11% | 1 | 0.18% |
| Benny Halevy | 16 | 0.11% | 2 | 0.36% |
| Dai Ngo | 13 | 0.09% | 1 | 0.18% |
| Nicholas Piggin | 11 | 0.07% | 3 | 0.54% |
| Fabio M. De Francesco | 11 | 0.07% | 3 | 0.54% |
| Sun Ke | 10 | 0.07% | 1 | 0.18% |
| Andi Kleen | 10 | 0.07% | 2 | 0.36% |
| J. Bruce Fields | 9 | 0.06% | 3 | 0.54% |
| Aneesh Kumar K.V | 9 | 0.06% | 2 | 0.36% |
| Niels de Vos | 9 | 0.06% | 1 | 0.18% |
| Dave Hansen | 7 | 0.05% | 2 | 0.36% |
| Dave Wysochanski | 6 | 0.04% | 1 | 0.18% |
| Catalin Marinas | 6 | 0.04% | 1 | 0.18% |
| Jan Kara | 6 | 0.04% | 1 | 0.18% |
| Peter Zijlstra | 6 | 0.04% | 1 | 0.18% |
| trondmy | 6 | 0.04% | 1 | 0.18% |
| Madhuparna Bhowmik | 4 | 0.03% | 1 | 0.18% |
| Ying Han | 4 | 0.03% | 1 | 0.18% |
| Christoph Hellwig | 4 | 0.03% | 2 | 0.36% |
| Thomas Meyer | 4 | 0.03% | 1 | 0.18% |
| Peter Staubach | 4 | 0.03% | 1 | 0.18% |
| Josef Bacik | 4 | 0.03% | 1 | 0.18% |
| Eric Paris | 4 | 0.03% | 1 | 0.18% |
| Rafael Aquini | 3 | 0.02% | 1 | 0.18% |
| Namhyung Kim | 3 | 0.02% | 1 | 0.18% |
| Peng Tao | 3 | 0.02% | 1 | 0.18% |
| Glauber de Oliveira Costa | 3 | 0.02% | 1 | 0.18% |
| Gustavo A. R. Silva | 3 | 0.02% | 2 | 0.36% |
| Adrian Bunk | 3 | 0.02% | 1 | 0.18% |
| Lance Shelton | 1 | 0.01% | 1 | 0.18% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.18% |
| Eric W. Biedermann | 1 | 0.01% | 1 | 0.18% |
| Dave Jones | 1 | 0.01% | 1 | 0.18% |
| Fabio Olive Leite | 1 | 0.01% | 1 | 0.18% |
| Harvey Harrison | 1 | 0.01% | 1 | 0.18% |
| luanshi | 1 | 0.01% | 1 | 0.18% |
| Andries E. Brouwer | 1 | 0.01% | 1 | 0.18% |
| Josef 'Jeff' Sipek | 1 | 0.01% | 1 | 0.18% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.18% |
| Scott Mayhew | 1 | 0.01% | 1 | 0.18% |
| Total | 15145 | 554 |
// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/nfs/dir.c * * Copyright (C) 1992 Rick Sladkey * * nfs directory handling functions * * 10 Apr 1996 Added silly rename for unlink --okir * 28 Sep 1996 Improved directory cache --okir * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de * Re-implemented silly rename for unlink, newly implemented * silly rename for nfs_rename() following the suggestions * of Olaf Kirch (okir) found in this file. * Following Linus comments on my original hack, this version * depends only on the dcache stuff and doesn't touch the inode * layer (iput() and friends). * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM */ #include <linux/compat.h> #include <linux/module.h> #include <linux/time.h> #include <linux/errno.h> #include <linux/stat.h> #include <linux/fcntl.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> #include <linux/nfs_mount.h> #include <linux/pagemap.h> #include <linux/pagevec.h> #include <linux/namei.h> #include <linux/mount.h> #include <linux/swap.h> #include <linux/sched.h> #include <linux/kmemleak.h> #include <linux/xattr.h> #include <linux/hash.h> #include "delegation.h" #include "iostat.h" #include "internal.h" #include "fscache.h" #include "nfstrace.h" /* #define NFS_DEBUG_VERBOSE 1 */ static int nfs_opendir(struct inode *, struct file *); static int nfs_closedir(struct inode *, struct file *); static int nfs_readdir(struct file *, struct dir_context *); static int nfs_fsync_dir(struct file *, loff_t, loff_t, int); static loff_t nfs_llseek_dir(struct file *, loff_t, int); static void nfs_readdir_clear_array(struct folio *); const struct file_operations nfs_dir_operations = { .llseek = nfs_llseek_dir, .read = generic_read_dir, .iterate_shared = nfs_readdir, .open = nfs_opendir, .release = nfs_closedir, .fsync = nfs_fsync_dir, }; const struct address_space_operations nfs_dir_aops = { .free_folio = nfs_readdir_clear_array, }; #define NFS_INIT_DTSIZE PAGE_SIZE static struct nfs_open_dir_context * alloc_nfs_open_dir_context(struct inode *dir) { struct nfs_inode *nfsi = NFS_I(dir); struct nfs_open_dir_context *ctx; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT); if (ctx != NULL) { ctx->attr_gencount = nfsi->attr_gencount; ctx->dtsize = NFS_INIT_DTSIZE; spin_lock(&dir->i_lock); if (list_empty(&nfsi->open_files) && (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER)) nfs_set_cache_invalid(dir, NFS_INO_INVALID_DATA | NFS_INO_REVAL_FORCED); list_add_tail_rcu(&ctx->list, &nfsi->open_files); memcpy(ctx->verf, nfsi->cookieverf, sizeof(ctx->verf)); spin_unlock(&dir->i_lock); return ctx; } return ERR_PTR(-ENOMEM); } static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx) { spin_lock(&dir->i_lock); list_del_rcu(&ctx->list); spin_unlock(&dir->i_lock); kfree_rcu(ctx, rcu_head); } /* * Open file */ static int nfs_opendir(struct inode *inode, struct file *filp) { int res = 0; struct nfs_open_dir_context *ctx; dfprintk(FILE, "NFS: open dir(%pD2)\n", filp); nfs_inc_stats(inode, NFSIOS_VFSOPEN); ctx = alloc_nfs_open_dir_context(inode); if (IS_ERR(ctx)) { res = PTR_ERR(ctx); goto out; } filp->private_data = ctx; out: return res; } static int nfs_closedir(struct inode *inode, struct file *filp) { put_nfs_open_dir_context(file_inode(filp), filp->private_data); return 0; } struct nfs_cache_array_entry { u64 cookie; u64 ino; const char *name; unsigned int name_len; unsigned char d_type; }; struct nfs_cache_array { u64 change_attr; u64 last_cookie; unsigned int size; unsigned char folio_full : 1, folio_is_eof : 1, cookies_are_ordered : 1; struct nfs_cache_array_entry array[]; }; struct nfs_readdir_descriptor { struct file *file; struct folio *folio; struct dir_context *ctx; pgoff_t folio_index; pgoff_t folio_index_max; u64 dir_cookie; u64 last_cookie; loff_t current_index; __be32 verf[NFS_DIR_VERIFIER_SIZE]; unsigned long dir_verifier; unsigned long timestamp; unsigned long gencount; unsigned long attr_gencount; unsigned int cache_entry_index; unsigned int buffer_fills; unsigned int dtsize; bool clear_cache; bool plus; bool eob; bool eof; }; static void nfs_set_dtsize(struct nfs_readdir_descriptor *desc, unsigned int sz) { struct nfs_server *server = NFS_SERVER(file_inode(desc->file)); unsigned int maxsize = server->dtsize; if (sz > maxsize) sz = maxsize; if (sz < NFS_MIN_FILE_IO_SIZE) sz = NFS_MIN_FILE_IO_SIZE; desc->dtsize = sz; } static void nfs_shrink_dtsize(struct nfs_readdir_descriptor *desc) { nfs_set_dtsize(desc, desc->dtsize >> 1); } static void nfs_grow_dtsize(struct nfs_readdir_descriptor *desc) { nfs_set_dtsize(desc, desc->dtsize << 1); } static void nfs_readdir_folio_init_array(struct folio *folio, u64 last_cookie, u64 change_attr) { struct nfs_cache_array *array; array = kmap_local_folio(folio, 0); array->change_attr = change_attr; array->last_cookie = last_cookie; array->size = 0; array->folio_full = 0; array->folio_is_eof = 0; array->cookies_are_ordered = 1; kunmap_local(array); } /* * we are freeing strings created by nfs_add_to_readdir_array() */ static void nfs_readdir_clear_array(struct folio *folio) { struct nfs_cache_array *array; unsigned int i; array = kmap_local_folio(folio, 0); for (i = 0; i < array->size; i++) kfree(array->array[i].name); array->size = 0; kunmap_local(array); } static void nfs_readdir_folio_reinit_array(struct folio *folio, u64 last_cookie, u64 change_attr) { nfs_readdir_clear_array(folio); nfs_readdir_folio_init_array(folio, last_cookie, change_attr); } static struct folio * nfs_readdir_folio_array_alloc(u64 last_cookie, gfp_t gfp_flags) { struct folio *folio = folio_alloc(gfp_flags, 0); if (folio) nfs_readdir_folio_init_array(folio, last_cookie, 0); return folio; } static void nfs_readdir_folio_array_free(struct folio *folio) { if (folio) { nfs_readdir_clear_array(folio); folio_put(folio); } } static u64 nfs_readdir_array_index_cookie(struct nfs_cache_array *array) { return array->size == 0 ? array->last_cookie : array->array[0].cookie; } static void nfs_readdir_array_set_eof(struct nfs_cache_array *array) { array->folio_is_eof = 1; array->folio_full = 1; } static bool nfs_readdir_array_is_full(struct nfs_cache_array *array) { return array->folio_full; } /* * the caller is responsible for freeing qstr.name * when called by nfs_readdir_add_to_array, the strings will be freed in * nfs_clear_readdir_array() */ static const char *nfs_readdir_copy_name(const char *name, unsigned int len) { const char *ret = kmemdup_nul(name, len, GFP_KERNEL); /* * Avoid a kmemleak false positive. The pointer to the name is stored * in a page cache page which kmemleak does not scan. */ if (ret != NULL) kmemleak_not_leak(ret); return ret; } static size_t nfs_readdir_array_maxentries(void) { return (PAGE_SIZE - sizeof(struct nfs_cache_array)) / sizeof(struct nfs_cache_array_entry); } /* * Check that the next array entry lies entirely within the page bounds */ static int nfs_readdir_array_can_expand(struct nfs_cache_array *array) { if (array->folio_full) return -ENOSPC; if (array->size == nfs_readdir_array_maxentries()) { array->folio_full = 1; return -ENOSPC; } return 0; } static int nfs_readdir_folio_array_append(struct folio *folio, const struct nfs_entry *entry, u64 *cookie) { struct nfs_cache_array *array; struct nfs_cache_array_entry *cache_entry; const char *name; int ret = -ENOMEM; name = nfs_readdir_copy_name(entry->name, entry->len); array = kmap_local_folio(folio, 0); if (!name) goto out; ret = nfs_readdir_array_can_expand(array); if (ret) { kfree(name); goto out; } cache_entry = &array->array[array->size]; cache_entry->cookie = array->last_cookie; cache_entry->ino = entry->ino; cache_entry->d_type = entry->d_type; cache_entry->name_len = entry->len; cache_entry->name = name; array->last_cookie = entry->cookie; if (array->last_cookie <= cache_entry->cookie) array->cookies_are_ordered = 0; array->size++; if (entry->eof != 0) nfs_readdir_array_set_eof(array); out: *cookie = array->last_cookie; kunmap_local(array); return ret; } #define NFS_READDIR_COOKIE_MASK (U32_MAX >> 14) /* * Hash algorithm allowing content addressible access to sequences * of directory cookies. Content is addressed by the value of the * cookie index of the first readdir entry in a page. * * We select only the first 18 bits to avoid issues with excessive * memory use for the page cache XArray. 18 bits should allow the caching * of 262144 pages of sequences of readdir entries. Since each page holds * 127 readdir entries for a typical 64-bit system, that works out to a * cache of ~ 33 million entries per directory. */ static pgoff_t nfs_readdir_folio_cookie_hash(u64 cookie) { if (cookie == 0) return 0; return hash_64(cookie, 18); } static bool nfs_readdir_folio_validate(struct folio *folio, u64 last_cookie, u64 change_attr) { struct nfs_cache_array *array = kmap_local_folio(folio, 0); int ret = true; if (array->change_attr != change_attr) ret = false; if (nfs_readdir_array_index_cookie(array) != last_cookie) ret = false; kunmap_local(array); return ret; } static void nfs_readdir_folio_unlock_and_put(struct folio *folio) { folio_unlock(folio); folio_put(folio); } static void nfs_readdir_folio_init_and_validate(struct folio *folio, u64 cookie, u64 change_attr) { if (folio_test_uptodate(folio)) { if (nfs_readdir_folio_validate(folio, cookie, change_attr)) return; nfs_readdir_clear_array(folio); } nfs_readdir_folio_init_array(folio, cookie, change_attr); folio_mark_uptodate(folio); } static struct folio *nfs_readdir_folio_get_locked(struct address_space *mapping, u64 cookie, u64 change_attr) { pgoff_t index = nfs_readdir_folio_cookie_hash(cookie); struct folio *folio; folio = filemap_grab_folio(mapping, index); if (IS_ERR(folio)) return NULL; nfs_readdir_folio_init_and_validate(folio, cookie, change_attr); return folio; } static u64 nfs_readdir_folio_last_cookie(struct folio *folio) { struct nfs_cache_array *array; u64 ret; array = kmap_local_folio(folio, 0); ret = array->last_cookie; kunmap_local(array); return ret; } static bool nfs_readdir_folio_needs_filling(struct folio *folio) { struct nfs_cache_array *array; bool ret; array = kmap_local_folio(folio, 0); ret = !nfs_readdir_array_is_full(array); kunmap_local(array); return ret; } static void nfs_readdir_folio_set_eof(struct folio *folio) { struct nfs_cache_array *array; array = kmap_local_folio(folio, 0); nfs_readdir_array_set_eof(array); kunmap_local(array); } static struct folio *nfs_readdir_folio_get_next(struct address_space *mapping, u64 cookie, u64 change_attr) { pgoff_t index = nfs_readdir_folio_cookie_hash(cookie); struct folio *folio; folio = __filemap_get_folio(mapping, index, FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT, mapping_gfp_mask(mapping)); if (IS_ERR(folio)) return NULL; nfs_readdir_folio_init_and_validate(folio, cookie, change_attr); if (nfs_readdir_folio_last_cookie(folio) != cookie) nfs_readdir_folio_reinit_array(folio, cookie, change_attr); return folio; } static inline int is_32bit_api(void) { #ifdef CONFIG_COMPAT return in_compat_syscall(); #else return (BITS_PER_LONG == 32); #endif } static bool nfs_readdir_use_cookie(const struct file *filp) { if ((filp->f_mode & FMODE_32BITHASH) || (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) return false; return true; } static void nfs_readdir_seek_next_array(struct nfs_cache_array *array, struct nfs_readdir_descriptor *desc) { if (array->folio_full) { desc->last_cookie = array->last_cookie; desc->current_index += array->size; desc->cache_entry_index = 0; desc->folio_index++; } else desc->last_cookie = nfs_readdir_array_index_cookie(array); } static void nfs_readdir_rewind_search(struct nfs_readdir_descriptor *desc) { desc->current_index = 0; desc->last_cookie = 0; desc->folio_index = 0; } static int nfs_readdir_search_for_pos(struct nfs_cache_array *array, struct nfs_readdir_descriptor *desc) { loff_t diff = desc->ctx->pos - desc->current_index; unsigned int index; if (diff < 0) goto out_eof; if (diff >= array->size) { if (array->folio_is_eof) goto out_eof; nfs_readdir_seek_next_array(array, desc); return -EAGAIN; } index = (unsigned int)diff; desc->dir_cookie = array->array[index].cookie; desc->cache_entry_index = index; return 0; out_eof: desc->eof = true; return -EBADCOOKIE; } static bool nfs_readdir_array_cookie_in_range(struct nfs_cache_array *array, u64 cookie) { if (!array->cookies_are_ordered) return true; /* Optimisation for monotonically increasing cookies */ if (cookie >= array->last_cookie) return false; if (array->size && cookie < array->array[0].cookie) return false; return true; } static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, struct nfs_readdir_descriptor *desc) { unsigned int i; int status = -EAGAIN; if (!nfs_readdir_array_cookie_in_range(array, desc->dir_cookie)) goto check_eof; for (i = 0; i < array->size; i++) { if (array->array[i].cookie == desc->dir_cookie) { if (nfs_readdir_use_cookie(desc->file)) desc->ctx->pos = desc->dir_cookie; else desc->ctx->pos = desc->current_index + i; desc->cache_entry_index = i; return 0; } } check_eof: if (array->folio_is_eof) { status = -EBADCOOKIE; if (desc->dir_cookie == array->last_cookie) desc->eof = true; } else nfs_readdir_seek_next_array(array, desc); return status; } static int nfs_readdir_search_array(struct nfs_readdir_descriptor *desc) { struct nfs_cache_array *array; int status; array = kmap_local_folio(desc->folio, 0); if (desc->dir_cookie == 0) status = nfs_readdir_search_for_pos(array, desc); else status = nfs_readdir_search_for_cookie(array, desc); kunmap_local(array); return status; } /* Fill a page with xdr information before transferring to the cache page */ static int nfs_readdir_xdr_filler(struct nfs_readdir_descriptor *desc, __be32 *verf, u64 cookie, struct page **pages, size_t bufsize, __be32 *verf_res) { struct inode *inode = file_inode(desc->file); struct nfs_readdir_arg arg = { .dentry = file_dentry(desc->file), .cred = desc->file->f_cred, .verf = verf, .cookie = cookie, .pages = pages, .page_len = bufsize, .plus = desc->plus, }; struct nfs_readdir_res res = { .verf = verf_res, }; unsigned long timestamp, gencount; int error; again: timestamp = jiffies; gencount = nfs_inc_attr_generation_counter(); desc->dir_verifier = nfs_save_change_attribute(inode); error = NFS_PROTO(inode)->readdir(&arg, &res); if (error < 0) { /* We requested READDIRPLUS, but the server doesn't grok it */ if (error == -ENOTSUPP && desc->plus) { NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; desc->plus = arg.plus = false; goto again; } goto error; } desc->timestamp = timestamp; desc->gencount = gencount; error: return error; } static int xdr_decode(struct nfs_readdir_descriptor *desc, struct nfs_entry *entry, struct xdr_stream *xdr) { struct inode *inode = file_inode(desc->file); int error; error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus); if (error) return error; entry->fattr->time_start = desc->timestamp; entry->fattr->gencount = desc->gencount; return 0; } /* Match file and dirent using either filehandle or fileid * Note: caller is responsible for checking the fsid */ static int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) { struct inode *inode; struct nfs_inode *nfsi; if (d_really_is_negative(dentry)) return 0; inode = d_inode(dentry); if (is_bad_inode(inode) || NFS_STALE(inode)) return 0; nfsi = NFS_I(inode); if (entry->fattr->fileid != nfsi->fileid) return 0; if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0) return 0; return 1; } #define NFS_READDIR_CACHE_USAGE_THRESHOLD (8UL) static bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx, unsigned int cache_hits, unsigned int cache_misses) { if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS)) return false; if (ctx->pos == 0 || cache_hits + cache_misses > NFS_READDIR_CACHE_USAGE_THRESHOLD) return true; return false; } /* * This function is called by the getattr code to request the * use of readdirplus to accelerate any future lookups in the same * directory. */ void nfs_readdir_record_entry_cache_hit(struct inode *dir) { struct nfs_inode *nfsi = NFS_I(dir); struct nfs_open_dir_context *ctx; if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && S_ISDIR(dir->i_mode)) { rcu_read_lock(); list_for_each_entry_rcu (ctx, &nfsi->open_files, list) atomic_inc(&ctx->cache_hits); rcu_read_unlock(); } } /* * This function is mainly for use by nfs_getattr(). * * If this is an 'ls -l', we want to force use of readdirplus. */ void nfs_readdir_record_entry_cache_miss(struct inode *dir) { struct nfs_inode *nfsi = NFS_I(dir); struct nfs_open_dir_context *ctx; if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && S_ISDIR(dir->i_mode)) { rcu_read_lock(); list_for_each_entry_rcu (ctx, &nfsi->open_files, list) atomic_inc(&ctx->cache_misses); rcu_read_unlock(); } } static void nfs_lookup_advise_force_readdirplus(struct inode *dir, unsigned int flags) { if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE)) return; if (flags & (LOOKUP_EXCL | LOOKUP_PARENT | LOOKUP_REVAL)) return; nfs_readdir_record_entry_cache_miss(dir); } static void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry, unsigned long dir_verifier) { struct qstr filename = QSTR_INIT(entry->name, entry->len); DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); struct dentry *dentry; struct dentry *alias; struct inode *inode; int status; if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID)) return; if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID)) return; if (filename.len == 0) return; /* Validate that the name doesn't contain any illegal '\0' */ if (strnlen(filename.name, filename.len) != filename.len) return; /* ...or '/' */ if (strnchr(filename.name, filename.len, '/')) return; if (filename.name[0] == '.') { if (filename.len == 1) return; if (filename.len == 2 && filename.name[1] == '.') return; } filename.hash = full_name_hash(parent, filename.name, filename.len); dentry = d_lookup(parent, &filename); again: if (!dentry) { dentry = d_alloc_parallel(parent, &filename, &wq); if (IS_ERR(dentry)) return; } if (!d_in_lookup(dentry)) { /* Is there a mountpoint here? If so, just exit */ if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid, &entry->fattr->fsid)) goto out; if (nfs_same_file(dentry, entry)) { if (!entry->fh->size) goto out; nfs_set_verifier(dentry, dir_verifier); status = nfs_refresh_inode(d_inode(dentry), entry->fattr); if (!status) nfs_setsecurity(d_inode(dentry), entry->fattr); trace_nfs_readdir_lookup_revalidate(d_inode(parent), dentry, 0, status); goto out; } else { trace_nfs_readdir_lookup_revalidate_failed( d_inode(parent), dentry, 0); d_invalidate(dentry); dput(dentry); dentry = NULL; goto again; } } if (!entry->fh->size) { d_lookup_done(dentry); goto out; } inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); alias = d_splice_alias(inode, dentry); d_lookup_done(dentry); if (alias) { if (IS_ERR(alias)) goto out; dput(dentry); dentry = alias; } nfs_set_verifier(dentry, dir_verifier); trace_nfs_readdir_lookup(d_inode(parent), dentry, 0); out: dput(dentry); } static int nfs_readdir_entry_decode(struct nfs_readdir_descriptor *desc, struct nfs_entry *entry, struct xdr_stream *stream) { int ret; if (entry->fattr->label) entry->fattr->label->len = NFS4_MAXLABELLEN; ret = xdr_decode(desc, entry, stream); if (ret || !desc->plus) return ret; nfs_prime_dcache(file_dentry(desc->file), entry, desc->dir_verifier); return 0; } /* Perform conversion from xdr to cache array */ static int nfs_readdir_folio_filler(struct nfs_readdir_descriptor *desc, struct nfs_entry *entry, struct page **xdr_pages, unsigned int buflen, struct folio **arrays, size_t narrays, u64 change_attr) { struct address_space *mapping = desc->file->f_mapping; struct folio *new, *folio = *arrays; struct xdr_stream stream; struct page *scratch; struct xdr_buf buf; u64 cookie; int status; scratch = alloc_page(GFP_KERNEL); if (scratch == NULL) return -ENOMEM; xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); xdr_set_scratch_page(&stream, scratch); do { status = nfs_readdir_entry_decode(desc, entry, &stream); if (status != 0) break; status = nfs_readdir_folio_array_append(folio, entry, &cookie); if (status != -ENOSPC) continue; if (folio->mapping != mapping) { if (!--narrays) break; new = nfs_readdir_folio_array_alloc(cookie, GFP_KERNEL); if (!new) break; arrays++; *arrays = folio = new; } else { new = nfs_readdir_folio_get_next(mapping, cookie, change_attr); if (!new) break; if (folio != *arrays) nfs_readdir_folio_unlock_and_put(folio); folio = new; } desc->folio_index_max++; status = nfs_readdir_folio_array_append(folio, entry, &cookie); } while (!status && !entry->eof); switch (status) { case -EBADCOOKIE: if (!entry->eof) break; nfs_readdir_folio_set_eof(folio); fallthrough; case -EAGAIN: status = 0; break; case -ENOSPC: status = 0; if (!desc->plus) break; while (!nfs_readdir_entry_decode(desc, entry, &stream)) ; } if (folio != *arrays) nfs_readdir_folio_unlock_and_put(folio); put_page(scratch); return status; } static void nfs_readdir_free_pages(struct page **pages, size_t npages) { while (npages--) put_page(pages[npages]); kfree(pages); } /* * nfs_readdir_alloc_pages() will allocate pages that must be freed with a call * to nfs_readdir_free_pages() */ static struct page **nfs_readdir_alloc_pages(size_t npages) { struct page **pages; size_t i; pages = kmalloc_array(npages, sizeof(*pages), GFP_KERNEL); if (!pages) return NULL; for (i = 0; i < npages; i++) { struct page *page = alloc_page(GFP_KERNEL); if (page == NULL) goto out_freepages; pages[i] = page; } return pages; out_freepages: nfs_readdir_free_pages(pages, i); return NULL; } static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc, __be32 *verf_arg, __be32 *verf_res, struct folio **arrays, size_t narrays) { u64 change_attr; struct page **pages; struct folio *folio = *arrays; struct nfs_entry *entry; size_t array_size; struct inode *inode = file_inode(desc->file); unsigned int dtsize = desc->dtsize; unsigned int pglen; int status = -ENOMEM; entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM; entry->cookie = nfs_readdir_folio_last_cookie(folio); entry->fh = nfs_alloc_fhandle(); entry->fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode)); entry->server = NFS_SERVER(inode); if (entry->fh == NULL || entry->fattr == NULL) goto out; array_size = (dtsize + PAGE_SIZE - 1) >> PAGE_SHIFT; pages = nfs_readdir_alloc_pages(array_size); if (!pages) goto out; change_attr = inode_peek_iversion_raw(inode); status = nfs_readdir_xdr_filler(desc, verf_arg, entry->cookie, pages, dtsize, verf_res); if (status < 0) goto free_pages; pglen = status; if (pglen != 0) status = nfs_readdir_folio_filler(desc, entry, pages, pglen, arrays, narrays, change_attr); else nfs_readdir_folio_set_eof(folio); desc->buffer_fills++; free_pages: nfs_readdir_free_pages(pages, array_size); out: nfs_free_fattr(entry->fattr); nfs_free_fhandle(entry->fh); kfree(entry); return status; } static void nfs_readdir_folio_put(struct nfs_readdir_descriptor *desc) { folio_put(desc->folio); desc->folio = NULL; } static void nfs_readdir_folio_unlock_and_put_cached(struct nfs_readdir_descriptor *desc) { folio_unlock(desc->folio); nfs_readdir_folio_put(desc); } static struct folio * nfs_readdir_folio_get_cached(struct nfs_readdir_descriptor *desc) { struct address_space *mapping = desc->file->f_mapping; u64 change_attr = inode_peek_iversion_raw(mapping->host); u64 cookie = desc->last_cookie; struct folio *folio; folio = nfs_readdir_folio_get_locked(mapping, cookie, change_attr); if (!folio) return NULL; if (desc->clear_cache && !nfs_readdir_folio_needs_filling(folio)) nfs_readdir_folio_reinit_array(folio, cookie, change_attr); return folio; } /* * Returns 0 if desc->dir_cookie was found on page desc->page_index * and locks the page to prevent removal from the page cache. */ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc) { struct inode *inode = file_inode(desc->file); struct nfs_inode *nfsi = NFS_I(inode); __be32 verf[NFS_DIR_VERIFIER_SIZE]; int res; desc->folio = nfs_readdir_folio_get_cached(desc); if (!desc->folio) return -ENOMEM; if (nfs_readdir_folio_needs_filling(desc->folio)) { /* Grow the dtsize if we had to go back for more pages */ if (desc->folio_index == desc->folio_index_max) nfs_grow_dtsize(desc); desc->folio_index_max = desc->folio_index; trace_nfs_readdir_cache_fill(desc->file, nfsi->cookieverf, desc->last_cookie, desc->folio->index, desc->dtsize); res = nfs_readdir_xdr_to_array(desc, nfsi->cookieverf, verf, &desc->folio, 1); if (res < 0) { nfs_readdir_folio_unlock_and_put_cached(desc); trace_nfs_readdir_cache_fill_done(inode, res); if (res == -EBADCOOKIE || res == -ENOTSYNC) { invalidate_inode_pages2(desc->file->f_mapping); nfs_readdir_rewind_search(desc); trace_nfs_readdir_invalidate_cache_range( inode, 0, MAX_LFS_FILESIZE); return -EAGAIN; } return res; } /* * Set the cookie verifier if the page cache was empty */ if (desc->last_cookie == 0 && memcmp(nfsi->cookieverf, verf, sizeof(nfsi->cookieverf))) { memcpy(nfsi->cookieverf, verf, sizeof(nfsi->cookieverf)); invalidate_inode_pages2_range(desc->file->f_mapping, 1, -1); trace_nfs_readdir_invalidate_cache_range( inode, 1, MAX_LFS_FILESIZE); } desc->clear_cache = false; } res = nfs_readdir_search_array(desc); if (res == 0) return 0; nfs_readdir_folio_unlock_and_put_cached(desc); return res; } /* Search for desc->dir_cookie from the beginning of the page cache */ static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc) { int res; do { res = find_and_lock_cache_page(desc); } while (res == -EAGAIN); return res; } #define NFS_READDIR_CACHE_MISS_THRESHOLD (16UL) /* * Once we've found the start of the dirent within a page: fill 'er up... */ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc, const __be32 *verf) { struct file *file = desc->file; struct nfs_cache_array *array; unsigned int i; bool first_emit = !desc->dir_cookie; array = kmap_local_folio(desc->folio, 0); for (i = desc->cache_entry_index; i < array->size; i++) { struct nfs_cache_array_entry *ent; /* * nfs_readdir_handle_cache_misses return force clear at * (cache_misses > NFS_READDIR_CACHE_MISS_THRESHOLD) for * readdir heuristic, NFS_READDIR_CACHE_MISS_THRESHOLD + 1 * entries need be emitted here. */ if (first_emit && i > NFS_READDIR_CACHE_MISS_THRESHOLD + 2) { desc->eob = true; break; } ent = &array->array[i]; if (!dir_emit(desc->ctx, ent->name, ent->name_len, nfs_compat_user_ino64(ent->ino), ent->d_type)) { desc->eob = true; break; } memcpy(desc->verf, verf, sizeof(desc->verf)); if (i == array->size - 1) { desc->dir_cookie = array->last_cookie; nfs_readdir_seek_next_array(array, desc); } else { desc->dir_cookie = array->array[i + 1].cookie; desc->last_cookie = array->array[0].cookie; } if (nfs_readdir_use_cookie(file)) desc->ctx->pos = desc->dir_cookie; else desc->ctx->pos++; } if (array->folio_is_eof) desc->eof = !desc->eob; kunmap_local(array); dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %llu\n", (unsigned long long)desc->dir_cookie); } /* * If we cannot find a cookie in our cache, we suspect that this is * because it points to a deleted file, so we ask the server to return * whatever it thinks is the next entry. We then feed this to filldir. * If all goes well, we should then be able to find our way round the * cache on the next call to readdir_search_pagecache(); * * NOTE: we cannot add the anonymous page to the pagecache because * the data it contains might not be page aligned. Besides, * we should already have a complete representation of the * directory in the page cache by the time we get here. */ static int uncached_readdir(struct nfs_readdir_descriptor *desc) { struct folio **arrays; size_t i, sz = 512; __be32 verf[NFS_DIR_VERIFIER_SIZE]; int status = -ENOMEM; dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %llu\n", (unsigned long long)desc->dir_cookie); arrays = kcalloc(sz, sizeof(*arrays), GFP_KERNEL); if (!arrays) goto out; arrays[0] = nfs_readdir_folio_array_alloc(desc->dir_cookie, GFP_KERNEL); if (!arrays[0]) goto out; desc->folio_index = 0; desc->cache_entry_index = 0; desc->last_cookie = desc->dir_cookie; desc->folio_index_max = 0; trace_nfs_readdir_uncached(desc->file, desc->verf, desc->last_cookie, -1, desc->dtsize); status = nfs_readdir_xdr_to_array(desc, desc->verf, verf, arrays, sz); if (status < 0) { trace_nfs_readdir_uncached_done(file_inode(desc->file), status); goto out_free; } for (i = 0; !desc->eob && i < sz && arrays[i]; i++) { desc->folio = arrays[i]; nfs_do_filldir(desc, verf); } desc->folio = NULL; /* * Grow the dtsize if we have to go back for more pages, * or shrink it if we're reading too many. */ if (!desc->eof) { if (!desc->eob) nfs_grow_dtsize(desc); else if (desc->buffer_fills == 1 && i < (desc->folio_index_max >> 1)) nfs_shrink_dtsize(desc); } out_free: for (i = 0; i < sz && arrays[i]; i++) nfs_readdir_folio_array_free(arrays[i]); out: if (!nfs_readdir_use_cookie(desc->file)) nfs_readdir_rewind_search(desc); desc->folio_index_max = -1; kfree(arrays); dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status); return status; } static bool nfs_readdir_handle_cache_misses(struct inode *inode, struct nfs_readdir_descriptor *desc, unsigned int cache_misses, bool force_clear) { if (desc->ctx->pos == 0 || !desc->plus) return false; if (cache_misses <= NFS_READDIR_CACHE_MISS_THRESHOLD && !force_clear) return false; trace_nfs_readdir_force_readdirplus(inode); return true; } /* The file offset position represents the dirent entry number. A last cookie cache takes care of the common case of reading the whole directory. */ static int nfs_readdir(struct file *file, struct dir_context *ctx) { struct dentry *dentry = file_dentry(file); struct inode *inode = d_inode(dentry); struct nfs_inode *nfsi = NFS_I(inode); struct nfs_open_dir_context *dir_ctx = file->private_data; struct nfs_readdir_descriptor *desc; unsigned int cache_hits, cache_misses; bool force_clear; int res; dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n", file, (long long)ctx->pos); nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); /* * ctx->pos points to the dirent entry number. * *desc->dir_cookie has the cookie for the next entry. We have * to either find the entry with the appropriate number or * revalidate the cookie. */ nfs_revalidate_mapping(inode, file->f_mapping); res = -ENOMEM; desc = kzalloc(sizeof(*desc), GFP_KERNEL); if (!desc) goto out; desc->file = file; desc->ctx = ctx; desc->folio_index_max = -1; spin_lock(&file->f_lock); desc->dir_cookie = dir_ctx->dir_cookie; desc->folio_index = dir_ctx->page_index; desc->last_cookie = dir_ctx->last_cookie; desc->attr_gencount = dir_ctx->attr_gencount; desc->eof = dir_ctx->eof; nfs_set_dtsize(desc, dir_ctx->dtsize); memcpy(desc->verf, dir_ctx->verf, sizeof(desc->verf)); cache_hits = atomic_xchg(&dir_ctx->cache_hits, 0); cache_misses = atomic_xchg(&dir_ctx->cache_misses, 0); force_clear = dir_ctx->force_clear; spin_unlock(&file->f_lock); if (desc->eof) { res = 0; goto out_free; } desc->plus = nfs_use_readdirplus(inode, ctx, cache_hits, cache_misses); force_clear = nfs_readdir_handle_cache_misses(inode, desc, cache_misses, force_clear); desc->clear_cache = force_clear; do { res = readdir_search_pagecache(desc); if (res == -EBADCOOKIE) { res = 0; /* This means either end of directory */ if (desc->dir_cookie && !desc->eof) { /* Or that the server has 'lost' a cookie */ res = uncached_readdir(desc); if (res == 0) continue; if (res == -EBADCOOKIE || res == -ENOTSYNC) res = 0; } break; } if (res == -ETOOSMALL && desc->plus) { nfs_zap_caches(inode); desc->plus = false; desc->eof = false; continue; } if (res < 0) break; nfs_do_filldir(desc, nfsi->cookieverf); nfs_readdir_folio_unlock_and_put_cached(desc); if (desc->folio_index == desc->folio_index_max) desc->clear_cache = force_clear; } while (!desc->eob && !desc->eof); spin_lock(&file->f_lock); dir_ctx->dir_cookie = desc->dir_cookie; dir_ctx->last_cookie = desc->last_cookie; dir_ctx->attr_gencount = desc->attr_gencount; dir_ctx->page_index = desc->folio_index; dir_ctx->force_clear = force_clear; dir_ctx->eof = desc->eof; dir_ctx->dtsize = desc->dtsize; memcpy(dir_ctx->verf, desc->verf, sizeof(dir_ctx->verf)); spin_unlock(&file->f_lock); out_free: kfree(desc); out: dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res); return res; } static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence) { struct nfs_open_dir_context *dir_ctx = filp->private_data; dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n", filp, offset, whence); switch (whence) { default: return -EINVAL; case SEEK_SET: if (offset < 0) return -EINVAL; spin_lock(&filp->f_lock); break; case SEEK_CUR: if (offset == 0) return filp->f_pos; spin_lock(&filp->f_lock); offset += filp->f_pos; if (offset < 0) { spin_unlock(&filp->f_lock); return -EINVAL; } } if (offset != filp->f_pos) { filp->f_pos = offset; dir_ctx->page_index = 0; if (!nfs_readdir_use_cookie(filp)) { dir_ctx->dir_cookie = 0; dir_ctx->last_cookie = 0; } else { dir_ctx->dir_cookie = offset; dir_ctx->last_cookie = offset; } dir_ctx->eof = false; } spin_unlock(&filp->f_lock); return offset; } /* * All directory operations under NFS are synchronous, so fsync() * is a dummy operation. */ static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end, int datasync) { dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync); nfs_inc_stats(file_inode(filp), NFSIOS_VFSFSYNC); return 0; } /** * nfs_force_lookup_revalidate - Mark the directory as having changed * @dir: pointer to directory inode * * This forces the revalidation code in nfs_lookup_revalidate() to do a * full lookup on all child dentries of 'dir' whenever a change occurs * on the server that might have invalidated our dcache. * * Note that we reserve bit '0' as a tag to let us know when a dentry * was revalidated while holding a delegation on its inode. * * The caller should be holding dir->i_lock */ void nfs_force_lookup_revalidate(struct inode *dir) { NFS_I(dir)->cache_change_attribute += 2; } EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate); /** * nfs_verify_change_attribute - Detects NFS remote directory changes * @dir: pointer to parent directory inode * @verf: previously saved change attribute * * Return "false" if the verifiers doesn't match the change attribute. * This would usually indicate that the directory contents have changed on * the server, and that any dentries need revalidating. */ static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf) { return (verf & ~1UL) == nfs_save_change_attribute(dir); } static void nfs_set_verifier_delegated(unsigned long *verf) { *verf |= 1UL; } #if IS_ENABLED(CONFIG_NFS_V4) static void nfs_unset_verifier_delegated(unsigned long *verf) { *verf &= ~1UL; } #endif /* IS_ENABLED(CONFIG_NFS_V4) */ static bool nfs_test_verifier_delegated(unsigned long verf) { return verf & 1; } static bool nfs_verifier_is_delegated(struct dentry *dentry) { return nfs_test_verifier_delegated(dentry->d_time); } static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf) { struct inode *inode = d_inode(dentry); struct inode *dir = d_inode_rcu(dentry->d_parent); if (!dir || !nfs_verify_change_attribute(dir, verf)) return; if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) nfs_set_verifier_delegated(&verf); dentry->d_time = verf; } /** * nfs_set_verifier - save a parent directory verifier in the dentry * @dentry: pointer to dentry * @verf: verifier to save * * Saves the parent directory verifier in @dentry. If the inode has * a delegation, we also tag the dentry as having been revalidated * while holding a delegation so that we know we don't have to * look it up again after a directory change. */ void nfs_set_verifier(struct dentry *dentry, unsigned long verf) { spin_lock(&dentry->d_lock); nfs_set_verifier_locked(dentry, verf); spin_unlock(&dentry->d_lock); } EXPORT_SYMBOL_GPL(nfs_set_verifier); #if IS_ENABLED(CONFIG_NFS_V4) /** * nfs_clear_verifier_delegated - clear the dir verifier delegation tag * @inode: pointer to inode * * Iterates through the dentries in the inode alias list and clears * the tag used to indicate that the dentry has been revalidated * while holding a delegation. * This function is intended for use when the delegation is being * returned or revoked. */ void nfs_clear_verifier_delegated(struct inode *inode) { struct dentry *alias; if (!inode) return; spin_lock(&inode->i_lock); hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { spin_lock(&alias->d_lock); nfs_unset_verifier_delegated(&alias->d_time); spin_unlock(&alias->d_lock); } spin_unlock(&inode->i_lock); } EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated); #endif /* IS_ENABLED(CONFIG_NFS_V4) */ static int nfs_dentry_verify_change(struct inode *dir, struct dentry *dentry) { if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE) && d_really_is_negative(dentry)) return dentry->d_time == inode_peek_iversion_raw(dir); return nfs_verify_change_attribute(dir, dentry->d_time); } /* * A check for whether or not the parent directory has changed. * In the case it has, we assume that the dentries are untrustworthy * and may need to be looked up again. * If rcu_walk prevents us from performing a full check, return 0. */ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry, int rcu_walk) { if (IS_ROOT(dentry)) return 1; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) return 0; if (!nfs_dentry_verify_change(dir, dentry)) return 0; /* Revalidate nfsi->cache_change_attribute before we declare a match */ if (nfs_mapping_need_revalidate_inode(dir)) { if (rcu_walk) return 0; if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) return 0; } if (!nfs_dentry_verify_change(dir, dentry)) return 0; return 1; } /* * Use intent information to check whether or not we're going to do * an O_EXCL create using this path component. */ static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags) { if (NFS_PROTO(dir)->version == 2) return 0; return flags & LOOKUP_EXCL; } /* * Inode and filehandle revalidation for lookups. * * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, * or if the intent information indicates that we're about to open this * particular file and the "nocto" mount flag is not set. * */ static int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags) { struct nfs_server *server = NFS_SERVER(inode); int ret; if (IS_AUTOMOUNT(inode)) return 0; if (flags & LOOKUP_OPEN) { switch (inode->i_mode & S_IFMT) { case S_IFREG: /* A NFSv4 OPEN will revalidate later */ if (server->caps & NFS_CAP_ATOMIC_OPEN) goto out; fallthrough; case S_IFDIR: if (server->flags & NFS_MOUNT_NOCTO) break; /* NFS close-to-open cache consistency validation */ goto out_force; } } /* VFS wants an on-the-wire revalidation */ if (flags & LOOKUP_REVAL) goto out_force; out: if (inode->i_nlink > 0 || (inode->i_nlink == 0 && test_bit(NFS_INO_PRESERVE_UNLINKED, &NFS_I(inode)->flags))) return 0; else return -ESTALE; out_force: if (flags & LOOKUP_RCU) return -ECHILD; ret = __nfs_revalidate_inode(server, inode); if (ret != 0) return ret; goto out; } static void nfs_mark_dir_for_revalidate(struct inode *inode) { spin_lock(&inode->i_lock); nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE); spin_unlock(&inode->i_lock); } /* * We judge how long we want to trust negative * dentries by looking at the parent inode mtime. * * If parent mtime has changed, we revalidate, else we wait for a * period corresponding to the parent's attribute cache timeout value. * * If LOOKUP_RCU prevents us from performing a full check, return 1 * suggesting a reval is needed. * * Note that when creating a new file, or looking up a rename target, * then it shouldn't be necessary to revalidate a negative dentry. */ static inline int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, unsigned int flags) { if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) return 0; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) return 1; /* Case insensitive server? Revalidate negative dentries */ if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE)) return 1; return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU); } static int nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry, struct inode *inode, int error) { switch (error) { case 1: break; case 0: /* * We can't d_drop the root of a disconnected tree: * its d_hash is on the s_anon list and d_drop() would hide * it from shrink_dcache_for_unmount(), leading to busy * inodes on unmount and further oopses. */ if (inode && IS_ROOT(dentry)) error = 1; break; } trace_nfs_lookup_revalidate_exit(dir, dentry, 0, error); return error; } static int nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry, unsigned int flags) { int ret = 1; if (nfs_neg_need_reval(dir, dentry, flags)) { if (flags & LOOKUP_RCU) return -ECHILD; ret = 0; } return nfs_lookup_revalidate_done(dir, dentry, NULL, ret); } static int nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry, struct inode *inode) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); return nfs_lookup_revalidate_done(dir, dentry, inode, 1); } static int nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry, struct inode *inode, unsigned int flags) { struct nfs_fh *fhandle; struct nfs_fattr *fattr; unsigned long dir_verifier; int ret; trace_nfs_lookup_revalidate_enter(dir, dentry, flags); ret = -ENOMEM; fhandle = nfs_alloc_fhandle(); fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode)); if (fhandle == NULL || fattr == NULL) goto out; dir_verifier = nfs_save_change_attribute(dir); ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr); if (ret < 0) { switch (ret) { case -ESTALE: case -ENOENT: ret = 0; break; case -ETIMEDOUT: if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL) ret = 1; } goto out; } /* Request help from readdirplus */ nfs_lookup_advise_force_readdirplus(dir, flags); ret = 0; if (nfs_compare_fh(NFS_FH(inode), fhandle)) goto out; if (nfs_refresh_inode(inode, fattr) < 0) goto out; nfs_setsecurity(inode, fattr); nfs_set_verifier(dentry, dir_verifier); ret = 1; out: nfs_free_fattr(fattr); nfs_free_fhandle(fhandle); /* * If the lookup failed despite the dentry change attribute being * a match, then we should revalidate the directory cache. */ if (!ret && nfs_dentry_verify_change(dir, dentry)) nfs_mark_dir_for_revalidate(dir); return nfs_lookup_revalidate_done(dir, dentry, inode, ret); } /* * This is called every time the dcache has a lookup hit, * and we should check whether we can really trust that * lookup. * * NOTE! The hit can be a negative hit too, don't assume * we have an inode! * * If the parent directory is seen to have changed, we throw out the * cached dentry and do a new lookup. */ static int nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; int error; nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); inode = d_inode(dentry); if (!inode) return nfs_lookup_revalidate_negative(dir, dentry, flags); if (is_bad_inode(inode)) { dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n", __func__, dentry); goto out_bad; } if ((flags & LOOKUP_RENAME_TARGET) && d_count(dentry) < 2 && nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE)) goto out_bad; if (nfs_verifier_is_delegated(dentry)) return nfs_lookup_revalidate_delegated(dir, dentry, inode); /* Force a full look up iff the parent directory has changed */ if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) && nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) { error = nfs_lookup_verify_inode(inode, flags); if (error) { if (error == -ESTALE) nfs_mark_dir_for_revalidate(dir); goto out_bad; } goto out_valid; } if (flags & LOOKUP_RCU) return -ECHILD; if (NFS_STALE(inode)) goto out_bad; return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags); out_valid: return nfs_lookup_revalidate_done(dir, dentry, inode, 1); out_bad: if (flags & LOOKUP_RCU) return -ECHILD; return nfs_lookup_revalidate_done(dir, dentry, inode, 0); } static int __nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags, int (*reval)(struct inode *, struct dentry *, unsigned int)) { struct dentry *parent; struct inode *dir; int ret; if (flags & LOOKUP_RCU) { if (dentry->d_fsdata == NFS_FSDATA_BLOCKED) return -ECHILD; parent = READ_ONCE(dentry->d_parent); dir = d_inode_rcu(parent); if (!dir) return -ECHILD; ret = reval(dir, dentry, flags); if (parent != READ_ONCE(dentry->d_parent)) return -ECHILD; } else { /* Wait for unlink to complete */ wait_var_event(&dentry->d_fsdata, dentry->d_fsdata != NFS_FSDATA_BLOCKED); parent = dget_parent(dentry); ret = reval(d_inode(parent), dentry, flags); dput(parent); } return ret; } static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) { return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate); } /* * A weaker form of d_revalidate for revalidating just the d_inode(dentry) * when we don't really care about the dentry name. This is called when a * pathwalk ends on a dentry that was not found via a normal lookup in the * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals). * * In this situation, we just want to verify that the inode itself is OK * since the dentry might have changed on the server. */ static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags) { struct inode *inode = d_inode(dentry); int error = 0; /* * I believe we can only get a negative dentry here in the case of a * procfs-style symlink. Just assume it's correct for now, but we may * eventually need to do something more here. */ if (!inode) { dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n", __func__, dentry); return 1; } if (is_bad_inode(inode)) { dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n", __func__, dentry); return 0; } error = nfs_lookup_verify_inode(inode, flags); dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n", __func__, inode->i_ino, error ? "invalid" : "valid"); return !error; } /* * This is called from dput() when d_count is going to 0. */ static int nfs_dentry_delete(const struct dentry *dentry) { dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n", dentry, dentry->d_flags); /* Unhash any dentry with a stale inode */ if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry))) return 1; if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { /* Unhash it, so that ->d_iput() would be called */ return 1; } if (!(dentry->d_sb->s_flags & SB_ACTIVE)) { /* Unhash it, so that ancestors of killed async unlink * files will be cleaned up during umount */ return 1; } return 0; } /* Ensure that we revalidate inode->i_nlink */ static void nfs_drop_nlink(struct inode *inode) { spin_lock(&inode->i_lock); /* drop the inode if we're reasonably sure this is the last link */ if (inode->i_nlink > 0) drop_nlink(inode); NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter(); nfs_set_cache_invalid( inode, NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME | NFS_INO_INVALID_NLINK); spin_unlock(&inode->i_lock); } /* * Called when the dentry loses inode. * We use it to clean up silly-renamed files. */ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) { if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { nfs_complete_unlink(dentry, inode); nfs_drop_nlink(inode); } iput(inode); } static void nfs_d_release(struct dentry *dentry) { /* free cached devname value, if it survived that far */ if (unlikely(dentry->d_fsdata)) { if (dentry->d_flags & DCACHE_NFSFS_RENAMED) WARN_ON(1); else kfree(dentry->d_fsdata); } } const struct dentry_operations nfs_dentry_operations = { .d_revalidate = nfs_lookup_revalidate, .d_weak_revalidate = nfs_weak_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, .d_automount = nfs_d_automount, .d_release = nfs_d_release, }; EXPORT_SYMBOL_GPL(nfs_dentry_operations); struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) { struct dentry *res; struct inode *inode = NULL; struct nfs_fh *fhandle = NULL; struct nfs_fattr *fattr = NULL; unsigned long dir_verifier; int error; dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry); nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen)) return ERR_PTR(-ENAMETOOLONG); /* * If we're doing an exclusive create, optimize away the lookup * but don't hash the dentry. */ if (nfs_is_exclusive_create(dir, flags) || flags & LOOKUP_RENAME_TARGET) return NULL; res = ERR_PTR(-ENOMEM); fhandle = nfs_alloc_fhandle(); fattr = nfs_alloc_fattr_with_label(NFS_SERVER(dir)); if (fhandle == NULL || fattr == NULL) goto out; dir_verifier = nfs_save_change_attribute(dir); trace_nfs_lookup_enter(dir, dentry, flags); error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr); if (error == -ENOENT) { if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE)) dir_verifier = inode_peek_iversion_raw(dir); goto no_entry; } if (error < 0) { res = ERR_PTR(error); goto out; } inode = nfs_fhget(dentry->d_sb, fhandle, fattr); res = ERR_CAST(inode); if (IS_ERR(res)) goto out; /* Notify readdir to use READDIRPLUS */ nfs_lookup_advise_force_readdirplus(dir, flags); no_entry: res = d_splice_alias(inode, dentry); if (res != NULL) { if (IS_ERR(res)) goto out; dentry = res; } nfs_set_verifier(dentry, dir_verifier); out: trace_nfs_lookup_exit(dir, dentry, flags, PTR_ERR_OR_ZERO(res)); nfs_free_fattr(fattr); nfs_free_fhandle(fhandle); return res; } EXPORT_SYMBOL_GPL(nfs_lookup); void nfs_d_prune_case_insensitive_aliases(struct inode *inode) { /* Case insensitive server? Revalidate dentries */ if (inode && nfs_server_capable(inode, NFS_CAP_CASE_INSENSITIVE)) d_prune_aliases(inode); } EXPORT_SYMBOL_GPL(nfs_d_prune_case_insensitive_aliases); #if IS_ENABLED(CONFIG_NFS_V4) static int nfs4_lookup_revalidate(struct dentry *, unsigned int); const struct dentry_operations nfs4_dentry_operations = { .d_revalidate = nfs4_lookup_revalidate, .d_weak_revalidate = nfs_weak_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, .d_automount = nfs_d_automount, .d_release = nfs_d_release, }; EXPORT_SYMBOL_GPL(nfs4_dentry_operations); static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp) { return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp); } static int do_open(struct inode *inode, struct file *filp) { nfs_fscache_open_file(inode, filp); return 0; } static int nfs_finish_open(struct nfs_open_context *ctx, struct dentry *dentry, struct file *file, unsigned open_flags) { int err; err = finish_open(file, dentry, do_open); if (err) goto out; if (S_ISREG(file_inode(file)->i_mode)) nfs_file_set_open_context(file, ctx); else err = -EOPENSTALE; out: return err; } int nfs_atomic_open(struct inode *dir, struct dentry *dentry, struct file *file, unsigned open_flags, umode_t mode) { DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); struct nfs_open_context *ctx; struct dentry *res; struct iattr attr = { .ia_valid = ATTR_OPEN }; struct inode *inode; unsigned int lookup_flags = 0; unsigned long dir_verifier; bool switched = false; int created = 0; int err; /* Expect a negative dentry */ BUG_ON(d_inode(dentry)); dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n", dir->i_sb->s_id, dir->i_ino, dentry); err = nfs_check_flags(open_flags); if (err) return err; /* NFS only supports OPEN on regular files */ if ((open_flags & O_DIRECTORY)) { if (!d_in_lookup(dentry)) { /* * Hashed negative dentry with O_DIRECTORY: dentry was * revalidated and is fine, no need to perform lookup * again */ return -ENOENT; } lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY; goto no_open; } if (dentry->d_name.len > NFS_SERVER(dir)->namelen) return -ENAMETOOLONG; if (open_flags & O_CREAT) { struct nfs_server *server = NFS_SERVER(dir); if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK)) mode &= ~current_umask(); attr.ia_valid |= ATTR_MODE; attr.ia_mode = mode; } if (open_flags & O_TRUNC) { attr.ia_valid |= ATTR_SIZE; attr.ia_size = 0; } if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) { d_drop(dentry); switched = true; dentry = d_alloc_parallel(dentry->d_parent, &dentry->d_name, &wq); if (IS_ERR(dentry)) return PTR_ERR(dentry); if (unlikely(!d_in_lookup(dentry))) return finish_no_open(file, dentry); } ctx = create_nfs_open_context(dentry, open_flags, file); err = PTR_ERR(ctx); if (IS_ERR(ctx)) goto out; trace_nfs_atomic_open_enter(dir, ctx, open_flags); inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, &created); if (created) file->f_mode |= FMODE_CREATED; if (IS_ERR(inode)) { err = PTR_ERR(inode); trace_nfs_atomic_open_exit(dir, ctx, open_flags, err); put_nfs_open_context(ctx); d_drop(dentry); switch (err) { case -ENOENT: d_splice_alias(NULL, dentry); if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE)) dir_verifier = inode_peek_iversion_raw(dir); else dir_verifier = nfs_save_change_attribute(dir); nfs_set_verifier(dentry, dir_verifier); break; case -EISDIR: case -ENOTDIR: goto no_open; case -ELOOP: if (!(open_flags & O_NOFOLLOW)) goto no_open; break; /* case -EINVAL: */ default: break; } goto out; } file->f_mode |= FMODE_CAN_ODIRECT; err = nfs_finish_open(ctx, ctx->dentry, file, open_flags); trace_nfs_atomic_open_exit(dir, ctx, open_flags, err); put_nfs_open_context(ctx); out: if (unlikely(switched)) { d_lookup_done(dentry); dput(dentry); } return err; no_open: res = nfs_lookup(dir, dentry, lookup_flags); if (!res) { inode = d_inode(dentry); if ((lookup_flags & LOOKUP_DIRECTORY) && inode && !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) res = ERR_PTR(-ENOTDIR); else if (inode && S_ISREG(inode->i_mode)) res = ERR_PTR(-EOPENSTALE); } else if (!IS_ERR(res)) { inode = d_inode(res); if ((lookup_flags & LOOKUP_DIRECTORY) && inode && !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) { dput(res); res = ERR_PTR(-ENOTDIR); } else if (inode && S_ISREG(inode->i_mode)) { dput(res); res = ERR_PTR(-EOPENSTALE); } } if (switched) { d_lookup_done(dentry); if (!res) res = dentry; else dput(dentry); } if (IS_ERR(res)) return PTR_ERR(res); return finish_no_open(file, res); } EXPORT_SYMBOL_GPL(nfs_atomic_open); static int nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; trace_nfs_lookup_revalidate_enter(dir, dentry, flags); if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY)) goto full_reval; if (d_mountpoint(dentry)) goto full_reval; inode = d_inode(dentry); /* We can't create new files in nfs_open_revalidate(), so we * optimize away revalidation of negative dentries. */ if (inode == NULL) goto full_reval; if (nfs_verifier_is_delegated(dentry)) return nfs_lookup_revalidate_delegated(dir, dentry, inode); /* NFS only supports OPEN on regular files */ if (!S_ISREG(inode->i_mode)) goto full_reval; /* We cannot do exclusive creation on a positive dentry */ if (flags & (LOOKUP_EXCL | LOOKUP_REVAL)) goto reval_dentry; /* Check if the directory changed */ if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) goto reval_dentry; /* Let f_op->open() actually open (and revalidate) the file */ return 1; reval_dentry: if (flags & LOOKUP_RCU) return -ECHILD; return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags); full_reval: return nfs_do_lookup_revalidate(dir, dentry, flags); } static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) { return __nfs_lookup_revalidate(dentry, flags, nfs4_do_lookup_revalidate); } #endif /* CONFIG_NFSV4 */ struct dentry * nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fhandle, struct nfs_fattr *fattr) { struct dentry *parent = dget_parent(dentry); struct inode *dir = d_inode(parent); struct inode *inode; struct dentry *d; int error; d_drop(dentry); if (fhandle->size == 0) { error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr); if (error) goto out_error; } nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); if (!(fattr->valid & NFS_ATTR_FATTR)) { struct nfs_server *server = NFS_SB(dentry->d_sb); error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr, NULL); if (error < 0) goto out_error; } inode = nfs_fhget(dentry->d_sb, fhandle, fattr); d = d_splice_alias(inode, dentry); out: dput(parent); return d; out_error: d = ERR_PTR(error); goto out; } EXPORT_SYMBOL_GPL(nfs_add_or_obtain); /* * Code common to create, mkdir, and mknod. */ int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, struct nfs_fattr *fattr) { struct dentry *d; d = nfs_add_or_obtain(dentry, fhandle, fattr); if (IS_ERR(d)) return PTR_ERR(d); /* Callers don't care */ dput(d); return 0; } EXPORT_SYMBOL_GPL(nfs_instantiate); /* * Following a failed create operation, we drop the dentry rather * than retain a negative dentry. This avoids a problem in the event * that the operation succeeded on the server, but an error in the * reply path made it appear to have failed. */ int nfs_create(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct iattr attr; int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT; int error; dfprintk(VFS, "NFS: create(%s/%lu), %pd\n", dir->i_sb->s_id, dir->i_ino, dentry); attr.ia_mode = mode; attr.ia_valid = ATTR_MODE; trace_nfs_create_enter(dir, dentry, open_flags); error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags); trace_nfs_create_exit(dir, dentry, open_flags, error); if (error != 0) goto out_err; return 0; out_err: d_drop(dentry); return error; } EXPORT_SYMBOL_GPL(nfs_create); /* * See comments for nfs_proc_create regarding failed operations. */ int nfs_mknod(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { struct iattr attr; int status; dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n", dir->i_sb->s_id, dir->i_ino, dentry); attr.ia_mode = mode; attr.ia_valid = ATTR_MODE; trace_nfs_mknod_enter(dir, dentry); status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); trace_nfs_mknod_exit(dir, dentry, status); if (status != 0) goto out_err; return 0; out_err: d_drop(dentry); return status; } EXPORT_SYMBOL_GPL(nfs_mknod); /* * See comments for nfs_proc_create regarding failed operations. */ int nfs_mkdir(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, umode_t mode) { struct iattr attr; int error; dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n", dir->i_sb->s_id, dir->i_ino, dentry); attr.ia_valid = ATTR_MODE; attr.ia_mode = mode | S_IFDIR; trace_nfs_mkdir_enter(dir, dentry); error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); trace_nfs_mkdir_exit(dir, dentry, error); if (error != 0) goto out_err; return 0; out_err: d_drop(dentry); return error; } EXPORT_SYMBOL_GPL(nfs_mkdir); static void nfs_dentry_handle_enoent(struct dentry *dentry) { if (simple_positive(dentry)) d_delete(dentry); } static void nfs_dentry_remove_handle_error(struct inode *dir, struct dentry *dentry, int error) { switch (error) { case -ENOENT: if (d_really_is_positive(dentry)) d_delete(dentry); nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); break; case 0: nfs_d_prune_case_insensitive_aliases(d_inode(dentry)); nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); } } int nfs_rmdir(struct inode *dir, struct dentry *dentry) { int error; dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n", dir->i_sb->s_id, dir->i_ino, dentry); trace_nfs_rmdir_enter(dir, dentry); if (d_really_is_positive(dentry)) { down_write(&NFS_I(d_inode(dentry))->rmdir_sem); error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); /* Ensure the VFS deletes this inode */ switch (error) { case 0: clear_nlink(d_inode(dentry)); break; case -ENOENT: nfs_dentry_handle_enoent(dentry); } up_write(&NFS_I(d_inode(dentry))->rmdir_sem); } else error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); nfs_dentry_remove_handle_error(dir, dentry, error); trace_nfs_rmdir_exit(dir, dentry, error); return error; } EXPORT_SYMBOL_GPL(nfs_rmdir); /* * Remove a file after making sure there are no pending writes, * and after checking that the file has only one user. * * We invalidate the attribute cache and free the inode prior to the operation * to avoid possible races if the server reuses the inode. */ static int nfs_safe_remove(struct dentry *dentry) { struct inode *dir = d_inode(dentry->d_parent); struct inode *inode = d_inode(dentry); int error = -EBUSY; dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry); /* If the dentry was sillyrenamed, we simply call d_delete() */ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { error = 0; goto out; } trace_nfs_remove_enter(dir, dentry); if (inode != NULL) { error = NFS_PROTO(dir)->remove(dir, dentry); if (error == 0) nfs_drop_nlink(inode); } else error = NFS_PROTO(dir)->remove(dir, dentry); if (error == -ENOENT) nfs_dentry_handle_enoent(dentry); trace_nfs_remove_exit(dir, dentry, error); out: return error; } /* We do silly rename. In case sillyrename() returns -EBUSY, the inode * belongs to an active ".nfs..." file and we return -EBUSY. * * If sillyrename() returns 0, we do nothing, otherwise we unlink. */ int nfs_unlink(struct inode *dir, struct dentry *dentry) { int error; dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id, dir->i_ino, dentry); trace_nfs_unlink_enter(dir, dentry); spin_lock(&dentry->d_lock); if (d_count(dentry) > 1 && !test_bit(NFS_INO_PRESERVE_UNLINKED, &NFS_I(d_inode(dentry))->flags)) { spin_unlock(&dentry->d_lock); /* Start asynchronous writeout of the inode */ write_inode_now(d_inode(dentry), 0); error = nfs_sillyrename(dir, dentry); goto out; } /* We must prevent any concurrent open until the unlink * completes. ->d_revalidate will wait for ->d_fsdata * to clear. We set it here to ensure no lookup succeeds until * the unlink is complete on the server. */ error = -ETXTBSY; if (WARN_ON(dentry->d_flags & DCACHE_NFSFS_RENAMED) || WARN_ON(dentry->d_fsdata == NFS_FSDATA_BLOCKED)) { spin_unlock(&dentry->d_lock); goto out; } /* old devname */ kfree(dentry->d_fsdata); dentry->d_fsdata = NFS_FSDATA_BLOCKED; spin_unlock(&dentry->d_lock); error = nfs_safe_remove(dentry); nfs_dentry_remove_handle_error(dir, dentry, error); dentry->d_fsdata = NULL; wake_up_var(&dentry->d_fsdata); out: trace_nfs_unlink_exit(dir, dentry, error); return error; } EXPORT_SYMBOL_GPL(nfs_unlink); /* * To create a symbolic link, most file systems instantiate a new inode, * add a page to it containing the path, then write it out to the disk * using prepare_write/commit_write. * * Unfortunately the NFS client can't create the in-core inode first * because it needs a file handle to create an in-core inode (see * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the * symlink request has completed on the server. * * So instead we allocate a raw page, copy the symname into it, then do * the SYMLINK request with the page as the buffer. If it succeeds, we * now have a new file handle and can instantiate an in-core NFS inode * and move the raw page into its mapping. */ int nfs_symlink(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, const char *symname) { struct folio *folio; char *kaddr; struct iattr attr; unsigned int pathlen = strlen(symname); int error; dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id, dir->i_ino, dentry, symname); if (pathlen > PAGE_SIZE) return -ENAMETOOLONG; attr.ia_mode = S_IFLNK | S_IRWXUGO; attr.ia_valid = ATTR_MODE; folio = folio_alloc(GFP_USER, 0); if (!folio) return -ENOMEM; kaddr = folio_address(folio); memcpy(kaddr, symname, pathlen); if (pathlen < PAGE_SIZE) memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); trace_nfs_symlink_enter(dir, dentry); error = NFS_PROTO(dir)->symlink(dir, dentry, folio, pathlen, &attr); trace_nfs_symlink_exit(dir, dentry, error); if (error != 0) { dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n", dir->i_sb->s_id, dir->i_ino, dentry, symname, error); d_drop(dentry); folio_put(folio); return error; } nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); /* * No big deal if we can't add this page to the page cache here. * READLINK will get the missing page from the server if needed. */ if (filemap_add_folio(d_inode(dentry)->i_mapping, folio, 0, GFP_KERNEL) == 0) { folio_mark_uptodate(folio); folio_unlock(folio); } folio_put(folio); return 0; } EXPORT_SYMBOL_GPL(nfs_symlink); int nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(old_dentry); int error; dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n", old_dentry, dentry); trace_nfs_link_enter(inode, dir, dentry); d_drop(dentry); if (S_ISREG(inode->i_mode)) nfs_sync_inode(inode); error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); if (error == 0) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); ihold(inode); d_add(dentry, inode); } trace_nfs_link_exit(inode, dir, dentry, error); return error; } EXPORT_SYMBOL_GPL(nfs_link); static void nfs_unblock_rename(struct rpc_task *task, struct nfs_renamedata *data) { struct dentry *new_dentry = data->new_dentry; new_dentry->d_fsdata = NULL; wake_up_var(&new_dentry->d_fsdata); } /* * RENAME * FIXME: Some nfsds, like the Linux user space nfsd, may generate a * different file handle for the same inode after a rename (e.g. when * moving to a different directory). A fail-safe method to do so would * be to look up old_dir/old_name, create a link to new_dir/new_name and * rename the old file using the sillyrename stuff. This way, the original * file in old_dir will go away when the last process iput()s the inode. * * FIXED. * * It actually works quite well. One needs to have the possibility for * at least one ".nfs..." file in each directory the file ever gets * moved or linked to which happens automagically with the new * implementation that only depends on the dcache stuff instead of * using the inode layer * * Unfortunately, things are a little more complicated than indicated * above. For a cross-directory move, we want to make sure we can get * rid of the old inode after the operation. This means there must be * no pending writes (if it's a file), and the use count must be 1. * If these conditions are met, we can drop the dentries before doing * the rename. */ int nfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { struct inode *old_inode = d_inode(old_dentry); struct inode *new_inode = d_inode(new_dentry); struct dentry *dentry = NULL; struct rpc_task *task; bool must_unblock = false; int error = -EBUSY; if (flags) return -EINVAL; dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n", old_dentry, new_dentry, d_count(new_dentry)); trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry); /* * For non-directories, check whether the target is busy and if so, * make a copy of the dentry and then do a silly-rename. If the * silly-rename succeeds, the copied dentry is hashed and becomes * the new target. */ if (new_inode && !S_ISDIR(new_inode->i_mode)) { /* We must prevent any concurrent open until the unlink * completes. ->d_revalidate will wait for ->d_fsdata * to clear. We set it here to ensure no lookup succeeds until * the unlink is complete on the server. */ error = -ETXTBSY; if (WARN_ON(new_dentry->d_flags & DCACHE_NFSFS_RENAMED) || WARN_ON(new_dentry->d_fsdata == NFS_FSDATA_BLOCKED)) goto out; if (new_dentry->d_fsdata) { /* old devname */ kfree(new_dentry->d_fsdata); new_dentry->d_fsdata = NULL; } spin_lock(&new_dentry->d_lock); if (d_count(new_dentry) > 2) { int err; spin_unlock(&new_dentry->d_lock); /* copy the target dentry's name */ dentry = d_alloc(new_dentry->d_parent, &new_dentry->d_name); if (!dentry) goto out; /* silly-rename the existing target ... */ err = nfs_sillyrename(new_dir, new_dentry); if (err) goto out; new_dentry = dentry; new_inode = NULL; } else { new_dentry->d_fsdata = NFS_FSDATA_BLOCKED; must_unblock = true; spin_unlock(&new_dentry->d_lock); } } if (S_ISREG(old_inode->i_mode)) nfs_sync_inode(old_inode); task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, must_unblock ? nfs_unblock_rename : NULL); if (IS_ERR(task)) { error = PTR_ERR(task); goto out; } error = rpc_wait_for_completion_task(task); if (error != 0) { ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1; /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */ smp_wmb(); } else error = task->tk_status; rpc_put_task(task); /* Ensure the inode attributes are revalidated */ if (error == 0) { spin_lock(&old_inode->i_lock); NFS_I(old_inode)->attr_gencount = nfs_inc_attr_generation_counter(); nfs_set_cache_invalid(old_inode, NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME | NFS_INO_REVAL_FORCED); spin_unlock(&old_inode->i_lock); } out: trace_nfs_rename_exit(old_dir, old_dentry, new_dir, new_dentry, error); if (!error) { if (new_inode != NULL) nfs_drop_nlink(new_inode); /* * The d_move() should be here instead of in an async RPC completion * handler because we need the proper locks to move the dentry. If * we're interrupted by a signal, the async RPC completion handler * should mark the directories for revalidation. */ d_move(old_dentry, new_dentry); nfs_set_verifier(old_dentry, nfs_save_change_attribute(new_dir)); } else if (error == -ENOENT) nfs_dentry_handle_enoent(old_dentry); /* new dentry created? */ if (dentry) dput(dentry); return error; } EXPORT_SYMBOL_GPL(nfs_rename); static DEFINE_SPINLOCK(nfs_access_lru_lock); static LIST_HEAD(nfs_access_lru_list); static atomic_long_t nfs_access_nr_entries; static unsigned long nfs_access_max_cachesize = 4*1024*1024; module_param(nfs_access_max_cachesize, ulong, 0644); MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length"); static void nfs_access_free_entry(struct nfs_access_entry *entry) { put_group_info(entry->group_info); kfree_rcu(entry, rcu_head); smp_mb__before_atomic(); atomic_long_dec(&nfs_access_nr_entries); smp_mb__after_atomic(); } static void nfs_access_free_list(struct list_head *head) { struct nfs_access_entry *cache; while (!list_empty(head)) { cache = list_entry(head->next, struct nfs_access_entry, lru); list_del(&cache->lru); nfs_access_free_entry(cache); } } static unsigned long nfs_do_access_cache_scan(unsigned int nr_to_scan) { LIST_HEAD(head); struct nfs_inode *nfsi, *next; struct nfs_access_entry *cache; long freed = 0; spin_lock(&nfs_access_lru_lock); list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { struct inode *inode; if (nr_to_scan-- == 0) break; inode = &nfsi->vfs_inode; spin_lock(&inode->i_lock); if (list_empty(&nfsi->access_cache_entry_lru)) goto remove_lru_entry; cache = list_entry(nfsi->access_cache_entry_lru.next, struct nfs_access_entry, lru); list_move(&cache->lru, &head); rb_erase(&cache->rb_node, &nfsi->access_cache); freed++; if (!list_empty(&nfsi->access_cache_entry_lru)) list_move_tail(&nfsi->access_cache_inode_lru, &nfs_access_lru_list); else { remove_lru_entry: list_del_init(&nfsi->access_cache_inode_lru); smp_mb__before_atomic(); clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); smp_mb__after_atomic(); } spin_unlock(&inode->i_lock); } spin_unlock(&nfs_access_lru_lock); nfs_access_free_list(&head); return freed; } unsigned long nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc) { int nr_to_scan = sc->nr_to_scan; gfp_t gfp_mask = sc->gfp_mask; if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) return SHRINK_STOP; return nfs_do_access_cache_scan(nr_to_scan); } unsigned long nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc) { return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries)); } static void nfs_access_cache_enforce_limit(void) { long nr_entries = atomic_long_read(&nfs_access_nr_entries); unsigned long diff; unsigned int nr_to_scan; if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize) return; nr_to_scan = 100; diff = nr_entries - nfs_access_max_cachesize; if (diff < nr_to_scan) nr_to_scan = diff; nfs_do_access_cache_scan(nr_to_scan); } static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) { struct rb_root *root_node = &nfsi->access_cache; struct rb_node *n; struct nfs_access_entry *entry; /* Unhook entries from the cache */ while ((n = rb_first(root_node)) != NULL) { entry = rb_entry(n, struct nfs_access_entry, rb_node); rb_erase(n, root_node); list_move(&entry->lru, head); } nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; } void nfs_access_zap_cache(struct inode *inode) { LIST_HEAD(head); if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) return; /* Remove from global LRU init */ spin_lock(&nfs_access_lru_lock); if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) list_del_init(&NFS_I(inode)->access_cache_inode_lru); spin_lock(&inode->i_lock); __nfs_access_zap_cache(NFS_I(inode), &head); spin_unlock(&inode->i_lock); spin_unlock(&nfs_access_lru_lock); nfs_access_free_list(&head); } EXPORT_SYMBOL_GPL(nfs_access_zap_cache); static int access_cmp(const struct cred *a, const struct nfs_access_entry *b) { struct group_info *ga, *gb; int g; if (uid_lt(a->fsuid, b->fsuid)) return -1; if (uid_gt(a->fsuid, b->fsuid)) return 1; if (gid_lt(a->fsgid, b->fsgid)) return -1; if (gid_gt(a->fsgid, b->fsgid)) return 1; ga = a->group_info; gb = b->group_info; if (ga == gb) return 0; if (ga == NULL) return -1; if (gb == NULL) return 1; if (ga->ngroups < gb->ngroups) return -1; if (ga->ngroups > gb->ngroups) return 1; for (g = 0; g < ga->ngroups; g++) { if (gid_lt(ga->gid[g], gb->gid[g])) return -1; if (gid_gt(ga->gid[g], gb->gid[g])) return 1; } return 0; } static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, const struct cred *cred) { struct rb_node *n = NFS_I(inode)->access_cache.rb_node; while (n != NULL) { struct nfs_access_entry *entry = rb_entry(n, struct nfs_access_entry, rb_node); int cmp = access_cmp(cred, entry); if (cmp < 0) n = n->rb_left; else if (cmp > 0) n = n->rb_right; else return entry; } return NULL; } static u64 nfs_access_login_time(const struct task_struct *task, const struct cred *cred) { const struct task_struct *parent; const struct cred *pcred; u64 ret; rcu_read_lock(); for (;;) { parent = rcu_dereference(task->real_parent); pcred = __task_cred(parent); if (parent == task || cred_fscmp(pcred, cred) != 0) break; task = parent; } ret = task->start_time; rcu_read_unlock(); return ret; } static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block) { struct nfs_inode *nfsi = NFS_I(inode); u64 login_time = nfs_access_login_time(current, cred); struct nfs_access_entry *cache; bool retry = true; int err; spin_lock(&inode->i_lock); for(;;) { if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) goto out_zap; cache = nfs_access_search_rbtree(inode, cred); err = -ENOENT; if (cache == NULL) goto out; /* Found an entry, is our attribute cache valid? */ if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS)) break; if (!retry) break; err = -ECHILD; if (!may_block) goto out; spin_unlock(&inode->i_lock); err = __nfs_revalidate_inode(NFS_SERVER(inode), inode); if (err) return err; spin_lock(&inode->i_lock); retry = false; } err = -ENOENT; if ((s64)(login_time - cache->timestamp) > 0) goto out; *mask = cache->mask; list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); err = 0; out: spin_unlock(&inode->i_lock); return err; out_zap: spin_unlock(&inode->i_lock); nfs_access_zap_cache(inode); return -ENOENT; } static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, u32 *mask) { /* Only check the most recently returned cache entry, * but do it without locking. */ struct nfs_inode *nfsi = NFS_I(inode); u64 login_time = nfs_access_login_time(current, cred); struct nfs_access_entry *cache; int err = -ECHILD; struct list_head *lh; rcu_read_lock(); if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) goto out; lh = rcu_dereference(list_tail_rcu(&nfsi->access_cache_entry_lru)); cache = list_entry(lh, struct nfs_access_entry, lru); if (lh == &nfsi->access_cache_entry_lru || access_cmp(cred, cache) != 0) cache = NULL; if (cache == NULL) goto out; if ((s64)(login_time - cache->timestamp) > 0) goto out; if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS)) goto out; *mask = cache->mask; err = 0; out: rcu_read_unlock(); return err; } int nfs_access_get_cached(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block) { int status; status = nfs_access_get_cached_rcu(inode, cred, mask); if (status != 0) status = nfs_access_get_cached_locked(inode, cred, mask, may_block); return status; } EXPORT_SYMBOL_GPL(nfs_access_get_cached); static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set, const struct cred *cred) { struct nfs_inode *nfsi = NFS_I(inode); struct rb_root *root_node = &nfsi->access_cache; struct rb_node **p = &root_node->rb_node; struct rb_node *parent = NULL; struct nfs_access_entry *entry; int cmp; spin_lock(&inode->i_lock); while (*p != NULL) { parent = *p; entry = rb_entry(parent, struct nfs_access_entry, rb_node); cmp = access_cmp(cred, entry); if (cmp < 0) p = &parent->rb_left; else if (cmp > 0) p = &parent->rb_right; else goto found; } rb_link_node(&set->rb_node, parent, p); rb_insert_color(&set->rb_node, root_node); list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); spin_unlock(&inode->i_lock); return; found: rb_replace_node(parent, &set->rb_node, root_node); list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); list_del(&entry->lru); spin_unlock(&inode->i_lock); nfs_access_free_entry(entry); } void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set, const struct cred *cred) { struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); if (cache == NULL) return; RB_CLEAR_NODE(&cache->rb_node); cache->fsuid = cred->fsuid; cache->fsgid = cred->fsgid; cache->group_info = get_group_info(cred->group_info); cache->mask = set->mask; cache->timestamp = ktime_get_ns(); /* The above field assignments must be visible * before this item appears on the lru. We cannot easily * use rcu_assign_pointer, so just force the memory barrier. */ smp_wmb(); nfs_access_add_rbtree(inode, cache, cred); /* Update accounting */ smp_mb__before_atomic(); atomic_long_inc(&nfs_access_nr_entries); smp_mb__after_atomic(); /* Add inode to global LRU list */ if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { spin_lock(&nfs_access_lru_lock); if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list); spin_unlock(&nfs_access_lru_lock); } nfs_access_cache_enforce_limit(); } EXPORT_SYMBOL_GPL(nfs_access_add_cache); #define NFS_MAY_READ (NFS_ACCESS_READ) #define NFS_MAY_WRITE (NFS_ACCESS_MODIFY | \ NFS_ACCESS_EXTEND | \ NFS_ACCESS_DELETE) #define NFS_FILE_MAY_WRITE (NFS_ACCESS_MODIFY | \ NFS_ACCESS_EXTEND) #define NFS_DIR_MAY_WRITE NFS_MAY_WRITE #define NFS_MAY_LOOKUP (NFS_ACCESS_LOOKUP) #define NFS_MAY_EXECUTE (NFS_ACCESS_EXECUTE) static int nfs_access_calc_mask(u32 access_result, umode_t umode) { int mask = 0; if (access_result & NFS_MAY_READ) mask |= MAY_READ; if (S_ISDIR(umode)) { if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE) mask |= MAY_WRITE; if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP) mask |= MAY_EXEC; } else if (S_ISREG(umode)) { if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE) mask |= MAY_WRITE; if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE) mask |= MAY_EXEC; } else if (access_result & NFS_MAY_WRITE) mask |= MAY_WRITE; return mask; } void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result) { entry->mask = access_result; } EXPORT_SYMBOL_GPL(nfs_access_set_mask); static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask) { struct nfs_access_entry cache; bool may_block = (mask & MAY_NOT_BLOCK) == 0; int cache_mask = -1; int status; trace_nfs_access_enter(inode); status = nfs_access_get_cached(inode, cred, &cache.mask, may_block); if (status == 0) goto out_cached; status = -ECHILD; if (!may_block) goto out; /* * Determine which access bits we want to ask for... */ cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND | nfs_access_xattr_mask(NFS_SERVER(inode)); if (S_ISDIR(inode->i_mode)) cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP; else cache.mask |= NFS_ACCESS_EXECUTE; status = NFS_PROTO(inode)->access(inode, &cache, cred); if (status != 0) { if (status == -ESTALE) { if (!S_ISDIR(inode->i_mode)) nfs_set_inode_stale(inode); else nfs_zap_caches(inode); } goto out; } nfs_access_add_cache(inode, &cache, cred); out_cached: cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode); if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0) status = -EACCES; out: trace_nfs_access_exit(inode, mask, cache_mask, status); return status; } static int nfs_open_permission_mask(int openflags) { int mask = 0; if (openflags & __FMODE_EXEC) { /* ONLY check exec rights */ mask = MAY_EXEC; } else { if ((openflags & O_ACCMODE) != O_WRONLY) mask |= MAY_READ; if ((openflags & O_ACCMODE) != O_RDONLY) mask |= MAY_WRITE; } return mask; } int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags) { return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); } EXPORT_SYMBOL_GPL(nfs_may_open); static int nfs_execute_ok(struct inode *inode, int mask) { struct nfs_server *server = NFS_SERVER(inode); int ret = 0; if (S_ISDIR(inode->i_mode)) return 0; if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_MODE)) { if (mask & MAY_NOT_BLOCK) return -ECHILD; ret = __nfs_revalidate_inode(server, inode); } if (ret == 0 && !execute_ok(inode)) ret = -EACCES; return ret; } int nfs_permission(struct mnt_idmap *idmap, struct inode *inode, int mask) { const struct cred *cred = current_cred(); int res = 0; nfs_inc_stats(inode, NFSIOS_VFSACCESS); if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) goto out; /* Is this sys_access() ? */ if (mask & (MAY_ACCESS | MAY_CHDIR)) goto force_lookup; switch (inode->i_mode & S_IFMT) { case S_IFLNK: goto out; case S_IFREG: if ((mask & MAY_OPEN) && nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)) return 0; break; case S_IFDIR: /* * Optimize away all write operations, since the server * will check permissions when we perform the op. */ if ((mask & MAY_WRITE) && !(mask & MAY_READ)) goto out; } force_lookup: if (!NFS_PROTO(inode)->access) goto out_notsup; res = nfs_do_access(inode, cred, mask); out: if (!res && (mask & MAY_EXEC)) res = nfs_execute_ok(inode, mask); dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n", inode->i_sb->s_id, inode->i_ino, mask, res); return res; out_notsup: if (mask & MAY_NOT_BLOCK) return -ECHILD; res = nfs_revalidate_inode(inode, NFS_INO_INVALID_MODE | NFS_INO_INVALID_OTHER); if (res == 0) res = generic_permission(&nop_mnt_idmap, inode, mask); goto out; } EXPORT_SYMBOL_GPL(nfs_permission);
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