// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2015, Primary Data, Inc. All rights reserved. * * Tao Peng <bergwolf@primarydata.com> */ #include <linux/dcache.h> #include <linux/exportfs.h> #include <linux/nfs.h> #include <linux/nfs_fs.h> #include "internal.h" #include "nfstrace.h" #define NFSDBG_FACILITY NFSDBG_VFS enum { FILEID_HIGH_OFF = 0, /* inode fileid high */ FILEID_LOW_OFF, /* inode fileid low */ FILE_I_TYPE_OFF, /* inode type */ EMBED_FH_OFF /* embeded server fh */ }; static struct nfs_fh *nfs_exp_embedfh(__u32 *p) { return (struct nfs_fh *)(p + EMBED_FH_OFF); } /* * Let's break subtree checking for now... otherwise we'll have to embed parent fh * but there might not be enough space. */ static int nfs_encode_fh(struct inode *inode, __u32 *p, int *max_len, struct inode *parent) { struct nfs_fh *server_fh = NFS_FH(inode); struct nfs_fh *clnt_fh = nfs_exp_embedfh(p); size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size; int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size); dprintk("%s: max fh len %d inode %p parent %p", __func__, *max_len, inode, parent); if (*max_len < len) { dprintk("%s: fh len %d too small, required %d\n", __func__, *max_len, len); *max_len = len; return FILEID_INVALID; } p[FILEID_HIGH_OFF] = NFS_FILEID(inode) >> 32; p[FILEID_LOW_OFF] = NFS_FILEID(inode); p[FILE_I_TYPE_OFF] = inode->i_mode & S_IFMT; p[len - 1] = 0; /* Padding */ nfs_copy_fh(clnt_fh, server_fh); *max_len = len; dprintk("%s: result fh fileid %llu mode %u size %d\n", __func__, NFS_FILEID(inode), inode->i_mode, *max_len); return *max_len; } static struct dentry * nfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct nfs_fattr *fattr = NULL; struct nfs_fh *server_fh = nfs_exp_embedfh(fid->raw); size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size; const struct nfs_rpc_ops *rpc_ops; struct dentry *dentry; struct inode *inode; int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size); u32 *p = fid->raw; int ret; /* NULL translates to ESTALE */ if (fh_len < len || fh_type != len) return NULL; fattr = nfs_alloc_fattr_with_label(NFS_SB(sb)); if (fattr == NULL) { dentry = ERR_PTR(-ENOMEM); goto out; } fattr->fileid = ((u64)p[FILEID_HIGH_OFF] << 32) + p[FILEID_LOW_OFF]; fattr->mode = p[FILE_I_TYPE_OFF]; fattr->valid |= NFS_ATTR_FATTR_FILEID | NFS_ATTR_FATTR_TYPE; dprintk("%s: fileid %llu mode %d\n", __func__, fattr->fileid, fattr->mode); inode = nfs_ilookup(sb, fattr, server_fh); if (inode) goto out_found; rpc_ops = NFS_SB(sb)->nfs_client->rpc_ops; ret = rpc_ops->getattr(NFS_SB(sb), server_fh, fattr, NULL); if (ret) { dprintk("%s: getattr failed %d\n", __func__, ret); trace_nfs_fh_to_dentry(sb, server_fh, fattr->fileid, ret); dentry = ERR_PTR(ret); goto out_free_fattr; } inode = nfs_fhget(sb, server_fh, fattr); out_found: dentry = d_obtain_alias(inode); out_free_fattr: nfs_free_fattr(fattr); out: return dentry; } static struct dentry * nfs_get_parent(struct dentry *dentry) { int ret; struct inode *inode = d_inode(dentry), *pinode; struct super_block *sb = inode->i_sb; struct nfs_server *server = NFS_SB(sb); struct nfs_fattr *fattr = NULL; struct dentry *parent; struct nfs_rpc_ops const *ops = server->nfs_client->rpc_ops; struct nfs_fh fh; if (!ops->lookupp) return ERR_PTR(-EACCES); fattr = nfs_alloc_fattr_with_label(server); if (fattr == NULL) return ERR_PTR(-ENOMEM); ret = ops->lookupp(inode, &fh, fattr); if (ret) { parent = ERR_PTR(ret); goto out; } pinode = nfs_fhget(sb, &fh, fattr); parent = d_obtain_alias(pinode); out: nfs_free_fattr(fattr); return parent; } const struct export_operations nfs_export_ops = { .encode_fh = nfs_encode_fh, .fh_to_dentry = nfs_fh_to_dentry, .get_parent = nfs_get_parent, .flags = EXPORT_OP_NOWCC | EXPORT_OP_NOSUBTREECHK | EXPORT_OP_CLOSE_BEFORE_UNLINK | EXPORT_OP_REMOTE_FS | EXPORT_OP_NOATOMIC_ATTR | EXPORT_OP_FLUSH_ON_CLOSE, };