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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | // 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, }; |