/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "nfs4_fs.h" #include "delegation.h" #include "iostat.h" #include "internal.h" /* #define NFS_DEBUG_VERBOSE 1 */ static int nfs_opendir(struct inode *, struct file *); static int nfs_readdir(struct file *, void *, filldir_t); static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); static int nfs_mkdir(struct inode *, struct dentry *, int); static int nfs_rmdir(struct inode *, struct dentry *); static int nfs_unlink(struct inode *, struct dentry *); static int nfs_symlink(struct inode *, struct dentry *, const char *); static int nfs_link(struct dentry *, struct inode *, struct dentry *); static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); static int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); static int nfs_fsync_dir(struct file *, struct dentry *, int); static loff_t nfs_llseek_dir(struct file *, loff_t, int); const struct file_operations nfs_dir_operations = { .llseek = nfs_llseek_dir, .read = generic_read_dir, .readdir = nfs_readdir, .open = nfs_opendir, .release = nfs_release, .fsync = nfs_fsync_dir, }; const struct inode_operations nfs_dir_inode_operations = { .create = nfs_create, .lookup = nfs_lookup, .link = nfs_link, .unlink = nfs_unlink, .symlink = nfs_symlink, .mkdir = nfs_mkdir, .rmdir = nfs_rmdir, .mknod = nfs_mknod, .rename = nfs_rename, .permission = nfs_permission, .getattr = nfs_getattr, .setattr = nfs_setattr, }; #ifdef CONFIG_NFS_V3 const struct inode_operations nfs3_dir_inode_operations = { .create = nfs_create, .lookup = nfs_lookup, .link = nfs_link, .unlink = nfs_unlink, .symlink = nfs_symlink, .mkdir = nfs_mkdir, .rmdir = nfs_rmdir, .mknod = nfs_mknod, .rename = nfs_rename, .permission = nfs_permission, .getattr = nfs_getattr, .setattr = nfs_setattr, .listxattr = nfs3_listxattr, .getxattr = nfs3_getxattr, .setxattr = nfs3_setxattr, .removexattr = nfs3_removexattr, }; #endif /* CONFIG_NFS_V3 */ #ifdef CONFIG_NFS_V4 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); const struct inode_operations nfs4_dir_inode_operations = { .create = nfs_create, .lookup = nfs_atomic_lookup, .link = nfs_link, .unlink = nfs_unlink, .symlink = nfs_symlink, .mkdir = nfs_mkdir, .rmdir = nfs_rmdir, .mknod = nfs_mknod, .rename = nfs_rename, .permission = nfs_permission, .getattr = nfs_getattr, .setattr = nfs_setattr, .getxattr = nfs4_getxattr, .setxattr = nfs4_setxattr, .listxattr = nfs4_listxattr, }; #endif /* CONFIG_NFS_V4 */ /* * Open file */ static int nfs_opendir(struct inode *inode, struct file *filp) { int res; dfprintk(FILE, "NFS: open dir(%s/%s)\n", filp->f_path.dentry->d_parent->d_name.name, filp->f_path.dentry->d_name.name); nfs_inc_stats(inode, NFSIOS_VFSOPEN); /* Call generic open code in order to cache credentials */ res = nfs_open(inode, filp); return res; } typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int); typedef struct { struct file *file; struct page *page; unsigned long page_index; __be32 *ptr; u64 *dir_cookie; loff_t current_index; struct nfs_entry *entry; decode_dirent_t decode; int plus; unsigned long timestamp; unsigned long gencount; int timestamp_valid; } nfs_readdir_descriptor_t; /* Now we cache directories properly, by stuffing the dirent * data directly in the page cache. * * Inode invalidation due to refresh etc. takes care of * _everything_, no sloppy entry flushing logic, no extraneous * copying, network direct to page cache, the way it was meant * to be. * * NOTE: Dirent information verification is done always by the * page-in of the RPC reply, nowhere else, this simplies * things substantially. */ static int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) { struct file *file = desc->file; struct inode *inode = file->f_path.dentry->d_inode; struct rpc_cred *cred = nfs_file_cred(file); unsigned long timestamp, gencount; int error; dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n", __func__, (long long)desc->entry->cookie, page->index); again: timestamp = jiffies; gencount = nfs_inc_attr_generation_counter(); error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page, NFS_SERVER(inode)->dtsize, desc->plus); 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; clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); desc->plus = 0; goto again; } goto error; } desc->timestamp = timestamp; desc->gencount = gencount; desc->timestamp_valid = 1; SetPageUptodate(page); /* Ensure consistent page alignment of the data. * Note: assumes we have exclusive access to this mapping either * through inode->i_mutex or some other mechanism. */ if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { /* Should never happen */ nfs_zap_mapping(inode, inode->i_mapping); } unlock_page(page); return 0; error: unlock_page(page); return -EIO; } static inline int dir_decode(nfs_readdir_descriptor_t *desc) { __be32 *p = desc->ptr; p = desc->decode(p, desc->entry, desc->plus); if (IS_ERR(p)) return PTR_ERR(p); desc->ptr = p; if (desc->timestamp_valid) { desc->entry->fattr->time_start = desc->timestamp; desc->entry->fattr->gencount = desc->gencount; } else desc->entry->fattr->valid &= ~NFS_ATTR_FATTR; return 0; } static inline void dir_page_release(nfs_readdir_descriptor_t *desc) { kunmap(desc->page); page_cache_release(desc->page); desc->page = NULL; desc->ptr = NULL; } /* * Given a pointer to a buffer that has already been filled by a call * to readdir, find the next entry with cookie '*desc->dir_cookie'. * * If the end of the buffer has been reached, return -EAGAIN, if not, * return the offset within the buffer of the next entry to be * read. */ static inline int find_dirent(nfs_readdir_descriptor_t *desc) { struct nfs_entry *entry = desc->entry; int loop_count = 0, status; while((status = dir_decode(desc)) == 0) { dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n", __func__, (unsigned long long)entry->cookie); if (entry->prev_cookie == *desc->dir_cookie) break; if (loop_count++ > 200) { loop_count = 0; schedule(); } } return status; } /* * Given a pointer to a buffer that has already been filled by a call * to readdir, find the entry at offset 'desc->file->f_pos'. * * If the end of the buffer has been reached, return -EAGAIN, if not, * return the offset within the buffer of the next entry to be * read. */ static inline int find_dirent_index(nfs_readdir_descriptor_t *desc) { struct nfs_entry *entry = desc->entry; int loop_count = 0, status; for(;;) { status = dir_decode(desc); if (status) break; dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n", (unsigned long long)entry->cookie, desc->current_index); if (desc->file->f_pos == desc->current_index) { *desc->dir_cookie = entry->cookie; break; } desc->current_index++; if (loop_count++ > 200) { loop_count = 0; schedule(); } } return status; } /* * Find the given page, and call find_dirent() or find_dirent_index in * order to try to return the next entry. */ static inline int find_dirent_page(nfs_readdir_descriptor_t *desc) { struct inode *inode = desc->file->f_path.dentry->d_inode; struct page *page; int status; dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n", __func__, desc->page_index, (long long) *desc->dir_cookie); /* If we find the page in the page_cache, we cannot be sure * how fresh the data is, so we will ignore readdir_plus attributes. */ desc->timestamp_valid = 0; page = read_cache_page(inode->i_mapping, desc->page_index, (filler_t *)nfs_readdir_filler, desc); if (IS_ERR(page)) { status = PTR_ERR(page); goto out; } /* NOTE: Someone else may have changed the READDIRPLUS flag */ desc->page = page; desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ if (*desc->dir_cookie != 0) status = find_dirent(desc); else status = find_dirent_index(desc); if (status < 0) dir_page_release(desc); out: dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status); return status; } /* * Recurse through the page cache pages, and return a * filled nfs_entry structure of the next directory entry if possible. * * The target for the search is '*desc->dir_cookie' if non-0, * 'desc->file->f_pos' otherwise */ static inline int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) { int loop_count = 0; int res; /* Always search-by-index from the beginning of the cache */ if (*desc->dir_cookie == 0) { dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n", (long long)desc->file->f_pos); desc->page_index = 0; desc->entry->cookie = desc->entry->prev_cookie = 0; desc->entry->eof = 0; desc->current_index = 0; } else dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (unsigned long long)*desc->dir_cookie); for (;;) { res = find_dirent_page(desc); if (res != -EAGAIN) break; /* Align to beginning of next page */ desc->page_index ++; if (loop_count++ > 200) { loop_count = 0; schedule(); } } dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, res); return res; } static inline unsigned int dt_type(struct inode *inode) { return (inode->i_mode >> 12) & 15; } static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc); /* * Once we've found the start of the dirent within a page: fill 'er up... */ static int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, filldir_t filldir) { struct file *file = desc->file; struct nfs_entry *entry = desc->entry; struct dentry *dentry = NULL; u64 fileid; int loop_count = 0, res; dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", (unsigned long long)entry->cookie); for(;;) { unsigned d_type = DT_UNKNOWN; /* Note: entry->prev_cookie contains the cookie for * retrieving the current dirent on the server */ fileid = entry->ino; /* Get a dentry if we have one */ if (dentry != NULL) dput(dentry); dentry = nfs_readdir_lookup(desc); /* Use readdirplus info */ if (dentry != NULL && dentry->d_inode != NULL) { d_type = dt_type(dentry->d_inode); fileid = NFS_FILEID(dentry->d_inode); } res = filldir(dirent, entry->name, entry->len, file->f_pos, nfs_compat_user_ino64(fileid), d_type); if (res < 0) break; file->f_pos++; *desc->dir_cookie = entry->cookie; if (dir_decode(desc) != 0) { desc->page_index ++; break; } if (loop_count++ > 200) { loop_count = 0; schedule(); } } dir_page_release(desc); if (dentry != NULL) dput(dentry); dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (unsigned long long)*desc->dir_cookie, res); return res; } /* * 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 inline int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, filldir_t filldir) { struct file *file = desc->file; struct inode *inode = file->f_path.dentry->d_inode; struct rpc_cred *cred = nfs_file_cred(file); struct page *page = NULL; int status; unsigned long timestamp, gencount; dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", (unsigned long long)*desc->dir_cookie); page = alloc_page(GFP_HIGHUSER); if (!page) { status = -ENOMEM; goto out; } timestamp = jiffies; gencount = nfs_inc_attr_generation_counter(); status = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, *desc->dir_cookie, page, NFS_SERVER(inode)->dtsize, desc->plus); desc->page = page; desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ if (status >= 0) { desc->timestamp = timestamp; desc->gencount = gencount; desc->timestamp_valid = 1; if ((status = dir_decode(desc)) == 0) desc->entry->prev_cookie = *desc->dir_cookie; } else status = -EIO; if (status < 0) goto out_release; status = nfs_do_filldir(desc, dirent, filldir); /* Reset read descriptor so it searches the page cache from * the start upon the next call to readdir_search_pagecache() */ desc->page_index = 0; desc->entry->cookie = desc->entry->prev_cookie = 0; desc->entry->eof = 0; out: dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status); return status; out_release: dir_page_release(desc); goto out; } /* 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 *filp, void *dirent, filldir_t filldir) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; nfs_readdir_descriptor_t my_desc, *desc = &my_desc; struct nfs_entry my_entry; struct nfs_fh fh; struct nfs_fattr fattr; long res; dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n", dentry->d_parent->d_name.name, dentry->d_name.name, (long long)filp->f_pos); nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); /* * filp->f_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. */ memset(desc, 0, sizeof(*desc)); desc->file = filp; desc->dir_cookie = &nfs_file_open_context(filp)->dir_cookie; desc->decode = NFS_PROTO(inode)->decode_dirent; desc->plus = NFS_USE_READDIRPLUS(inode); my_entry.cookie = my_entry.prev_cookie = 0; my_entry.eof = 0; my_entry.fh = &fh; my_entry.fattr = &fattr; nfs_fattr_init(&fattr); desc->entry = &my_entry; nfs_block_sillyrename(dentry); res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping); if (res < 0) goto out; while(!desc->entry->eof) { res = readdir_search_pagecache(desc); if (res == -EBADCOOKIE) { /* This means either end of directory */ if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) { /* Or that the server has 'lost' a cookie */ res = uncached_readdir(desc, dirent, filldir); if (res >= 0) continue; } res = 0; break; } if (res == -ETOOSMALL && desc->plus) { clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); nfs_zap_caches(inode); desc->plus = 0; desc->entry->eof = 0; continue; } if (res < 0) break; res = nfs_do_filldir(desc, dirent, filldir); if (res < 0) { res = 0; break; } } out: nfs_unblock_sillyrename(dentry); if (res > 0) res = 0; dfprintk(FILE, "NFS: readdir(%s/%s) returns %ld\n", dentry->d_parent->d_name.name, dentry->d_name.name, res); return res; } static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n", dentry->d_parent->d_name.name, dentry->d_name.name, offset, origin); mutex_lock(&inode->i_mutex); switch (origin) { case 1: offset += filp->f_pos; case 0: if (offset >= 0) break; default: offset = -EINVAL; goto out; } if (offset != filp->f_pos) { filp->f_pos = offset; nfs_file_open_context(filp)->dir_cookie = 0; } out: mutex_unlock(&inode->i_mutex); return offset; } /* * All directory operations under NFS are synchronous, so fsync() * is a dummy operation. */ static int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync) { dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", dentry->d_parent->d_name.name, dentry->d_name.name, datasync); nfs_inc_stats(dentry->d_inode, 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. * * The caller should be holding dir->i_lock */ void nfs_force_lookup_revalidate(struct inode *dir) { NFS_I(dir)->cache_change_attribute++; } /* * 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. */ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) { if (IS_ROOT(dentry)) return 1; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) return 0; if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; /* Revalidate nfsi->cache_change_attribute before we declare a match */ if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) return 0; if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; return 1; } /* * Return the intent data that applies to this particular path component * * Note that the current set of intents only apply to the very last * component of the path. * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. */ static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask) { if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) return 0; return nd->flags & mask; } /* * 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, struct nameidata *nd) { if (NFS_PROTO(dir)->version == 2) return 0; return nd && nfs_lookup_check_intent(nd, 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 inline int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) { struct nfs_server *server = NFS_SERVER(inode); if (test_bit(NFS_INO_MOUNTPOINT, &NFS_I(inode)->flags)) return 0; if (nd != NULL) { /* VFS wants an on-the-wire revalidation */ if (nd->flags & LOOKUP_REVAL) goto out_force; /* This is an open(2) */ if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && !(server->flags & NFS_MOUNT_NOCTO) && (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) goto out_force; return 0; } return nfs_revalidate_inode(server, inode); out_force: return __nfs_revalidate_inode(server, inode); } /* * 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. */ static inline int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { /* Don't revalidate a negative dentry if we're creating a new file */ if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) return 0; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) return 1; return !nfs_check_verifier(dir, dentry); } /* * 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_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) { struct inode *dir; struct inode *inode; struct dentry *parent; int error; struct nfs_fh fhandle; struct nfs_fattr fattr; parent = dget_parent(dentry); dir = parent->d_inode; nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); inode = dentry->d_inode; if (!inode) { if (nfs_neg_need_reval(dir, dentry, nd)) goto out_bad; goto out_valid; } if (is_bad_inode(inode)) { dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", __func__, dentry->d_parent->d_name.name, dentry->d_name.name); goto out_bad; } /* Force a full look up iff the parent directory has changed */ if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) { if (nfs_lookup_verify_inode(inode, nd)) goto out_zap_parent; goto out_valid; } if (NFS_STALE(inode)) goto out_bad; error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); if (error) goto out_bad; if (nfs_compare_fh(NFS_FH(inode), &fhandle)) goto out_bad; if ((error = nfs_refresh_inode(inode, &fattr)) != 0) goto out_bad; nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); out_valid: dput(parent); dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", __func__, dentry->d_parent->d_name.name, dentry->d_name.name); return 1; out_zap_parent: nfs_zap_caches(dir); out_bad: nfs_mark_for_revalidate(dir); if (inode && S_ISDIR(inode->i_mode)) { /* Purge readdir caches. */ nfs_zap_caches(inode); /* If we have submounts, don't unhash ! */ if (have_submounts(dentry)) goto out_valid; shrink_dcache_parent(dentry); } d_drop(dentry); dput(parent); dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", __func__, dentry->d_parent->d_name.name, dentry->d_name.name); return 0; } /* * This is called from dput() when d_count is going to 0. */ static int nfs_dentry_delete(struct dentry *dentry) { dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", dentry->d_parent->d_name.name, dentry->d_name.name, dentry->d_flags); /* Unhash any dentry with a stale inode */ if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) 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 & MS_ACTIVE)) { /* Unhash it, so that ancestors of killed async unlink * files will be cleaned up during umount */ return 1; } return 0; } static void nfs_drop_nlink(struct inode *inode) { spin_lock(&inode->i_lock); if (inode->i_nlink > 0) drop_nlink(inode); 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 (S_ISDIR(inode->i_mode)) /* drop any readdir cache as it could easily be old */ NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { drop_nlink(inode); nfs_complete_unlink(dentry, inode); } iput(inode); } struct dentry_operations nfs_dentry_operations = { .d_revalidate = nfs_lookup_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, }; static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct dentry *res; struct dentry *parent; struct inode *inode = NULL; int error; struct nfs_fh fhandle; struct nfs_fattr fattr; dfprintk(VFS, "NFS: lookup(%s/%s)\n", dentry->d_parent->d_name.name, dentry->d_name.name); nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); res = ERR_PTR(-ENAMETOOLONG); if (dentry->d_name.len > NFS_SERVER(dir)->namelen) goto out; res = ERR_PTR(-ENOMEM); dentry->d_op = NFS_PROTO(dir)->dentry_ops; /* * If we're doing an exclusive create, optimize away the lookup * but don't hash the dentry. */ if (nfs_is_exclusive_create(dir, nd)) { d_instantiate(dentry, NULL); res = NULL; goto out; } parent = dentry->d_parent; /* Protect against concurrent sillydeletes */ nfs_block_sillyrename(parent); error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); if (error == -ENOENT) goto no_entry; if (error < 0) { res = ERR_PTR(error); goto out_unblock_sillyrename; } inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr); res = (struct dentry *)inode; if (IS_ERR(res)) goto out_unblock_sillyrename; no_entry: res = d_materialise_unique(dentry, inode); if (res != NULL) { if (IS_ERR(res)) goto out_unblock_sillyrename; dentry = res; } nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); out_unblock_sillyrename: nfs_unblock_sillyrename(parent); out: return res; } #ifdef CONFIG_NFS_V4 static int nfs_open_revalidate(struct dentry *, struct nameidata *); struct dentry_operations nfs4_dentry_operations = { .d_revalidate = nfs_open_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, }; /* * Use intent information to determine whether we need to substitute * the NFSv4-style stateful OPEN for the LOOKUP call */ static int is_atomic_open(struct nameidata *nd) { if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) return 0; /* NFS does not (yet) have a stateful open for directories */ if (nd->flags & LOOKUP_DIRECTORY) return 0; /* Are we trying to write to a read only partition? */ if (__mnt_is_readonly(nd->path.mnt) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) return 0; return 1; } static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct dentry *res = NULL; int error; dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); /* Check that we are indeed trying to open this file */ if (!is_atomic_open(nd)) goto no_open; if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { res = ERR_PTR(-ENAMETOOLONG); goto out; } dentry->d_op = NFS_PROTO(dir)->dentry_ops; /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash * the dentry. */ if (nd->flags & LOOKUP_EXCL) { d_instantiate(dentry, NULL); goto out; } /* Open the file on the server */ res = nfs4_atomic_open(dir, dentry, nd); if (IS_ERR(res)) { error = PTR_ERR(res); switch (error) { /* Make a negative dentry */ case -ENOENT: res = NULL; goto out; /* This turned out not to be a regular file */ case -EISDIR: case -ENOTDIR: goto no_open; case -ELOOP: if (!(nd->intent.open.flags & O_NOFOLLOW)) goto no_open; /* case -EINVAL: */ default: goto out; } } else if (res != NULL) dentry = res; out: return res; no_open: return nfs_lookup(dir, dentry, nd); } static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) { struct dentry *parent = NULL; struct inode *inode = dentry->d_inode; struct inode *dir; int openflags, ret = 0; if (!is_atomic_open(nd)) goto no_open; parent = dget_parent(dentry); dir = parent->d_inode; /* We can't create new files in nfs_open_revalidate(), so we * optimize away revalidation of negative dentries. */ if (inode == NULL) { if (!nfs_neg_need_reval(dir, dentry, nd)) ret = 1; goto out; } /* NFS only supports OPEN on regular files */ if (!S_ISREG(inode->i_mode)) goto no_open_dput; openflags = nd->intent.open.flags; /* We cannot do exclusive creation on a positive dentry */ if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) goto no_open_dput; /* We can't create new files, or truncate existing ones here */ openflags &= ~(O_CREAT|O_TRUNC); /* * Note: we're not holding inode->i_mutex and so may be racing with * operations that change the directory. We therefore save the * change attribute *before* we do the RPC call. */ ret = nfs4_open_revalidate(dir, dentry, openflags, nd); out: dput(parent); if (!ret) d_drop(dentry); return ret; no_open_dput: dput(parent); no_open: if (inode != NULL && nfs_have_delegation(inode, FMODE_READ)) return 1; return nfs_lookup_revalidate(dentry, nd); } #endif /* CONFIG_NFSV4 */ static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc) { struct dentry *parent = desc->file->f_path.dentry; struct inode *dir = parent->d_inode; struct nfs_entry *entry = desc->entry; struct dentry *dentry, *alias; struct qstr name = { .name = entry->name, .len = entry->len, }; struct inode *inode; unsigned long verf = nfs_save_change_attribute(dir); switch (name.len) { case 2: if (name.name[0] == '.' && name.name[1] == '.') return dget_parent(parent); break; case 1: if (name.name[0] == '.') return dget(parent); } spin_lock(&dir->i_lock); if (NFS_I(dir)->cache_validity & NFS_INO_INVALID_DATA) { spin_unlock(&dir->i_lock); return NULL; } spin_unlock(&dir->i_lock); name.hash = full_name_hash(name.name, name.len); dentry = d_lookup(parent, &name); if (dentry != NULL) { /* Is this a positive dentry that matches the readdir info? */ if (dentry->d_inode != NULL && (NFS_FILEID(dentry->d_inode) == entry->ino || d_mountpoint(dentry))) { if (!desc->plus || entry->fh->size == 0) return dentry; if (nfs_compare_fh(NFS_FH(dentry->d_inode), entry->fh) == 0) goto out_renew; } /* No, so d_drop to allow one to be created */ d_drop(dentry); dput(dentry); } if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR)) return NULL; if (name.len > NFS_SERVER(dir)->namelen) return NULL; /* Note: caller is already holding the dir->i_mutex! */ dentry = d_alloc(parent, &name); if (dentry == NULL) return NULL; dentry->d_op = NFS_PROTO(dir)->dentry_ops; inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); if (IS_ERR(inode)) { dput(dentry); return NULL; } alias = d_materialise_unique(dentry, inode); if (alias != NULL) { dput(dentry); if (IS_ERR(alias)) return NULL; dentry = alias; } out_renew: nfs_set_verifier(dentry, verf); return dentry; } /* * Code common to create, mkdir, and mknod. */ int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, struct nfs_fattr *fattr) { struct dentry *parent = dget_parent(dentry); struct inode *dir = parent->d_inode; struct inode *inode; int error = -EACCES; d_drop(dentry); /* We may have been initialized further down */ if (dentry->d_inode) goto out; if (fhandle->size == 0) { error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, 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); if (error < 0) goto out_error; } inode = nfs_fhget(dentry->d_sb, fhandle, fattr); error = PTR_ERR(inode); if (IS_ERR(inode)) goto out_error; d_add(dentry, inode); out: dput(parent); return 0; out_error: nfs_mark_for_revalidate(dir); dput(parent); return error; } /* * 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. */ static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { struct iattr attr; int error; int open_flags = 0; dfprintk(VFS, "NFS: create(%s/%ld), %s\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); attr.ia_mode = mode; attr.ia_valid = ATTR_MODE; if ((nd->flags & LOOKUP_CREATE) != 0) open_flags = nd->intent.open.flags; error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd); if (error != 0) goto out_err; return 0; out_err: d_drop(dentry); return error; } /* * See comments for nfs_proc_create regarding failed operations. */ static int nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) { struct iattr attr; int status; dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); if (!new_valid_dev(rdev)) return -EINVAL; attr.ia_mode = mode; attr.ia_valid = ATTR_MODE; status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); if (status != 0) goto out_err; return 0; out_err: d_drop(dentry); return status; } /* * See comments for nfs_proc_create regarding failed operations. */ static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct iattr attr; int error; dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); attr.ia_valid = ATTR_MODE; attr.ia_mode = mode | S_IFDIR; error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); if (error != 0) goto out_err; return 0; out_err: d_drop(dentry); return error; } static void nfs_dentry_handle_enoent(struct dentry *dentry) { if (dentry->d_inode != NULL && !d_unhashed(dentry)) d_delete(dentry); } static int nfs_rmdir(struct inode *dir, struct dentry *dentry) { int error; dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); /* Ensure the VFS deletes this inode */ if (error == 0 && dentry->d_inode != NULL) clear_nlink(dentry->d_inode); else if (error == -ENOENT) nfs_dentry_handle_enoent(dentry); return error; } static int nfs_sillyrename(struct inode *dir, struct dentry *dentry) { static unsigned int sillycounter; const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2; const int countersize = sizeof(sillycounter)*2; const int slen = sizeof(".nfs")+fileidsize+countersize-1; char silly[slen+1]; struct qstr qsilly; struct dentry *sdentry; int error = -EIO; dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n", dentry->d_parent->d_name.name, dentry->d_name.name, atomic_read(&dentry->d_count)); nfs_inc_stats(dir, NFSIOS_SILLYRENAME); /* * We don't allow a dentry to be silly-renamed twice. */ error = -EBUSY; if (dentry->d_flags & DCACHE_NFSFS_RENAMED) goto out; sprintf(silly, ".nfs%*.*Lx", fileidsize, fileidsize, (unsigned long long)NFS_FILEID(dentry->d_inode)); /* Return delegation in anticipation of the rename */ nfs_inode_return_delegation(dentry->d_inode); sdentry = NULL; do { char *suffix = silly + slen - countersize; dput(sdentry); sillycounter++; sprintf(suffix, "%*.*x", countersize, countersize, sillycounter); dfprintk(VFS, "NFS: trying to rename %s to %s\n", dentry->d_name.name, silly); sdentry = lookup_one_len(silly, dentry->d_parent, slen); /* * N.B. Better to return EBUSY here ... it could be * dangerous to delete the file while it's in use. */ if (IS_ERR(sdentry)) goto out; } while(sdentry->d_inode != NULL); /* need negative lookup */ qsilly.name = silly; qsilly.len = strlen(silly); if (dentry->d_inode) { error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, dir, &qsilly); nfs_mark_for_revalidate(dentry->d_inode); } else error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, dir, &qsilly); if (!error) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); d_move(dentry, sdentry); error = nfs_async_unlink(dir, dentry); /* If we return 0 we don't unlink */ } dput(sdentry); out: return error; } /* * 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 = dentry->d_parent->d_inode; struct inode *inode = dentry->d_inode; int error = -EBUSY; dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", dentry->d_parent->d_name.name, dentry->d_name.name); /* If the dentry was sillyrenamed, we simply call d_delete() */ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { error = 0; goto out; } if (inode != NULL) { nfs_inode_return_delegation(inode); error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); /* The VFS may want to delete this inode */ if (error == 0) nfs_drop_nlink(inode); nfs_mark_for_revalidate(inode); } else error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); if (error == -ENOENT) nfs_dentry_handle_enoent(dentry); 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. */ static int nfs_unlink(struct inode *dir, struct dentry *dentry) { int error; int need_rehash = 0; dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (atomic_read(&dentry->d_count) > 1) { spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); /* Start asynchronous writeout of the inode */ write_inode_now(dentry->d_inode, 0); error = nfs_sillyrename(dir, dentry); return error; } if (!d_unhashed(dentry)) { __d_drop(dentry); need_rehash = 1; } spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); error = nfs_safe_remove(dentry); if (!error || error == -ENOENT) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); } else if (need_rehash) d_rehash(dentry); return error; } /* * 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. */ static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct pagevec lru_pvec; struct page *page; char *kaddr; struct iattr attr; unsigned int pathlen = strlen(symname); int error; dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name, symname); if (pathlen > PAGE_SIZE) return -ENAMETOOLONG; attr.ia_mode = S_IFLNK | S_IRWXUGO; attr.ia_valid = ATTR_MODE; page = alloc_page(GFP_HIGHUSER); if (!page) return -ENOMEM; kaddr = kmap_atomic(page, KM_USER0); memcpy(kaddr, symname, pathlen); if (pathlen < PAGE_SIZE) memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); kunmap_atomic(kaddr, KM_USER0); error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); if (error != 0) { dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name, symname, error); d_drop(dentry); __free_page(page); return error; } /* * 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. */ pagevec_init(&lru_pvec, 0); if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, GFP_KERNEL)) { pagevec_add(&lru_pvec, page); pagevec_lru_add_file(&lru_pvec); SetPageUptodate(page); unlock_page(page); } else __free_page(page); return 0; } static int nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = old_dentry->d_inode; int error; dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", old_dentry->d_parent->d_name.name, old_dentry->d_name.name, dentry->d_parent->d_name.name, dentry->d_name.name); d_drop(dentry); error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); if (error == 0) { atomic_inc(&inode->i_count); d_add(dentry, inode); } return error; } /* * 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. */ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct inode *old_inode = old_dentry->d_inode; struct inode *new_inode = new_dentry->d_inode; struct dentry *dentry = NULL, *rehash = NULL; int error = -EBUSY; /* * To prevent any new references to the target during the rename, * we unhash the dentry and free the inode in advance. */ if (!d_unhashed(new_dentry)) { d_drop(new_dentry); rehash = new_dentry; } dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", old_dentry->d_parent->d_name.name, old_dentry->d_name.name, new_dentry->d_parent->d_name.name, new_dentry->d_name.name, atomic_read(&new_dentry->d_count)); /* * First check whether the target is busy ... we can't * safely do _any_ rename if the target is in use. * * For files, 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) goto go_ahead; if (S_ISDIR(new_inode->i_mode)) { error = -EISDIR; if (!S_ISDIR(old_inode->i_mode)) goto out; } else if (atomic_read(&new_dentry->d_count) > 2) { int err; /* 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) { new_dentry = rehash = dentry; new_inode = NULL; /* instantiate the replacement target */ d_instantiate(new_dentry, NULL); } else if (atomic_read(&new_dentry->d_count) > 1) /* dentry still busy? */ goto out; } else nfs_drop_nlink(new_inode); go_ahead: /* * ... prune child dentries and writebacks if needed. */ if (atomic_read(&old_dentry->d_count) > 1) { if (S_ISREG(old_inode->i_mode)) nfs_wb_all(old_inode); shrink_dcache_parent(old_dentry); } nfs_inode_return_delegation(old_inode); if (new_inode != NULL) { nfs_inode_return_delegation(new_inode); d_delete(new_dentry); } error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, new_dir, &new_dentry->d_name); nfs_mark_for_revalidate(old_inode); out: if (rehash) d_rehash(rehash); if (!error) { d_move(old_dentry, new_dentry); nfs_set_verifier(new_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; } static DEFINE_SPINLOCK(nfs_access_lru_lock); static LIST_HEAD(nfs_access_lru_list); static atomic_long_t nfs_access_nr_entries; static void nfs_access_free_entry(struct nfs_access_entry *entry) { put_rpccred(entry->cred); kfree(entry); smp_mb__before_atomic_dec(); atomic_long_dec(&nfs_access_nr_entries); smp_mb__after_atomic_dec(); } int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) { LIST_HEAD(head); struct nfs_inode *nfsi; struct nfs_access_entry *cache; restart: spin_lock(&nfs_access_lru_lock); list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) { struct rw_semaphore *s_umount; struct inode *inode; if (nr_to_scan-- == 0) break; s_umount = &nfsi->vfs_inode.i_sb->s_umount; if (!down_read_trylock(s_umount)) continue; inode = igrab(&nfsi->vfs_inode); if (inode == NULL) { up_read(s_umount); continue; } 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); 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); clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); } spin_unlock(&inode->i_lock); spin_unlock(&nfs_access_lru_lock); iput(inode); up_read(s_umount); goto restart; } spin_unlock(&nfs_access_lru_lock); while (!list_empty(&head)) { cache = list_entry(head.next, struct nfs_access_entry, lru); list_del(&cache->lru); nfs_access_free_entry(cache); } return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; } static void __nfs_access_zap_cache(struct inode *inode) { struct nfs_inode *nfsi = NFS_I(inode); struct rb_root *root_node = &nfsi->access_cache; struct rb_node *n, *dispose = NULL; 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_del(&entry->lru); n->rb_left = dispose; dispose = n; } nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; spin_unlock(&inode->i_lock); /* Now kill them all! */ while (dispose != NULL) { n = dispose; dispose = n->rb_left; nfs_access_free_entry(rb_entry(n, struct nfs_access_entry, rb_node)); } } void nfs_access_zap_cache(struct inode *inode) { /* Remove from global LRU init */ if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { spin_lock(&nfs_access_lru_lock); list_del_init(&NFS_I(inode)->access_cache_inode_lru); spin_unlock(&nfs_access_lru_lock); } spin_lock(&inode->i_lock); /* This will release the spinlock */ __nfs_access_zap_cache(inode); } static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) { struct rb_node *n = NFS_I(inode)->access_cache.rb_node; struct nfs_access_entry *entry; while (n != NULL) { entry = rb_entry(n, struct nfs_access_entry, rb_node); if (cred < entry->cred) n = n->rb_left; else if (cred > entry->cred) n = n->rb_right; else return entry; } return NULL; } static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) { struct nfs_inode *nfsi = NFS_I(inode); struct nfs_access_entry *cache; int err = -ENOENT; spin_lock(&inode->i_lock); if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) goto out_zap; cache = nfs_access_search_rbtree(inode, cred); if (cache == NULL) goto out; if (!time_in_range(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) goto out_stale; res->jiffies = cache->jiffies; res->cred = cache->cred; res->mask = cache->mask; list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); err = 0; out: spin_unlock(&inode->i_lock); return err; out_stale: rb_erase(&cache->rb_node, &nfsi->access_cache); list_del(&cache->lru); spin_unlock(&inode->i_lock); nfs_access_free_entry(cache); return -ENOENT; out_zap: /* This will release the spinlock */ __nfs_access_zap_cache(inode); return -ENOENT; } static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) { 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; spin_lock(&inode->i_lock); while (*p != NULL) { parent = *p; entry = rb_entry(parent, struct nfs_access_entry, rb_node); if (set->cred < entry->cred) p = &parent->rb_left; else if (set->cred > entry->cred) 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); } static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) { struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); if (cache == NULL) return; RB_CLEAR_NODE(&cache->rb_node); cache->jiffies = set->jiffies; cache->cred = get_rpccred(set->cred); cache->mask = set->mask; nfs_access_add_rbtree(inode, cache); /* Update accounting */ smp_mb__before_atomic_inc(); atomic_long_inc(&nfs_access_nr_entries); smp_mb__after_atomic_inc(); /* Add inode to global LRU list */ if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { spin_lock(&nfs_access_lru_lock); list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list); spin_unlock(&nfs_access_lru_lock); } } static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) { struct nfs_access_entry cache; int status; status = nfs_access_get_cached(inode, cred, &cache); if (status == 0) goto out; /* Be clever: ask server to check for all possible rights */ cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; cache.cred = cred; cache.jiffies = jiffies; status = NFS_PROTO(inode)->access(inode, &cache); if (status != 0) return status; nfs_access_add_cache(inode, &cache); out: if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) return 0; return -EACCES; } static int nfs_open_permission_mask(int openflags) { int mask = 0; if (openflags & FMODE_READ) mask |= MAY_READ; if (openflags & FMODE_WRITE) mask |= MAY_WRITE; if (openflags & FMODE_EXEC) mask |= MAY_EXEC; return mask; } int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) { return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); } int nfs_permission(struct inode *inode, int mask) { struct rpc_cred *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) goto force_lookup; switch (inode->i_mode & S_IFMT) { case S_IFLNK: goto out; case S_IFREG: /* NFSv4 has atomic_open... */ if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) && (mask & MAY_OPEN)) goto out; 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; cred = rpc_lookup_cred(); if (!IS_ERR(cred)) { res = nfs_do_access(inode, cred, mask); put_rpccred(cred); } else res = PTR_ERR(cred); out: if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) res = -EACCES; dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", inode->i_sb->s_id, inode->i_ino, mask, res); return res; out_notsup: res = nfs_revalidate_inode(NFS_SERVER(inode), inode); if (res == 0) res = generic_permission(inode, mask, NULL); goto out; } /* * Local variables: * version-control: t * kept-new-versions: 5 * End: */