1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 4 * 5 * This file describes the layout of the file handles as passed 6 * over the wire. 7 */ 8 #ifndef _LINUX_NFSD_NFSFH_H 9 #define _LINUX_NFSD_NFSFH_H 10 11 #include <linux/crc32.h> 12 #include <linux/sunrpc/svc.h> 13 #include <uapi/linux/nfsd/nfsfh.h> 14 #include <linux/iversion.h> 15 #include <linux/exportfs.h> 16 17 static inline __u32 ino_t_to_u32(ino_t ino) 18 { 19 return (__u32) ino; 20 } 21 22 static inline ino_t u32_to_ino_t(__u32 uino) 23 { 24 return (ino_t) uino; 25 } 26 27 /* 28 * This is the internal representation of an NFS handle used in knfsd. 29 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3. 30 */ 31 typedef struct svc_fh { 32 struct knfsd_fh fh_handle; /* FH data */ 33 int fh_maxsize; /* max size for fh_handle */ 34 struct dentry * fh_dentry; /* validated dentry */ 35 struct svc_export * fh_export; /* export pointer */ 36 37 bool fh_locked; /* inode locked by us */ 38 bool fh_want_write; /* remount protection taken */ 39 bool fh_no_wcc; /* no wcc data needed */ 40 bool fh_no_atomic_attr; 41 /* 42 * wcc data is not atomic with 43 * operation 44 */ 45 int fh_flags; /* FH flags */ 46 #ifdef CONFIG_NFSD_V3 47 bool fh_post_saved; /* post-op attrs saved */ 48 bool fh_pre_saved; /* pre-op attrs saved */ 49 50 /* Pre-op attributes saved during fh_lock */ 51 __u64 fh_pre_size; /* size before operation */ 52 struct timespec64 fh_pre_mtime; /* mtime before oper */ 53 struct timespec64 fh_pre_ctime; /* ctime before oper */ 54 /* 55 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode) 56 * to find out if it is valid. 57 */ 58 u64 fh_pre_change; 59 60 /* Post-op attributes saved in fh_unlock */ 61 struct kstat fh_post_attr; /* full attrs after operation */ 62 u64 fh_post_change; /* nfsv4 change; see above */ 63 #endif /* CONFIG_NFSD_V3 */ 64 } svc_fh; 65 #define NFSD4_FH_FOREIGN (1<<0) 66 #define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f)) 67 #define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f)) 68 69 enum nfsd_fsid { 70 FSID_DEV = 0, 71 FSID_NUM, 72 FSID_MAJOR_MINOR, 73 FSID_ENCODE_DEV, 74 FSID_UUID4_INUM, 75 FSID_UUID8, 76 FSID_UUID16, 77 FSID_UUID16_INUM, 78 }; 79 80 enum fsid_source { 81 FSIDSOURCE_DEV, 82 FSIDSOURCE_FSID, 83 FSIDSOURCE_UUID, 84 }; 85 extern enum fsid_source fsid_source(const struct svc_fh *fhp); 86 87 88 /* 89 * This might look a little large to "inline" but in all calls except 90 * one, 'vers' is constant so moste of the function disappears. 91 * 92 * In some cases the values are considered to be host endian and in 93 * others, net endian. fsidv is always considered to be u32 as the 94 * callers don't know which it will be. So we must use __force to keep 95 * sparse from complaining. Since these values are opaque to the 96 * client, that shouldn't be a problem. 97 */ 98 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino, 99 u32 fsid, unsigned char *uuid) 100 { 101 u32 *up; 102 switch(vers) { 103 case FSID_DEV: 104 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) | 105 MINOR(dev)); 106 fsidv[1] = ino_t_to_u32(ino); 107 break; 108 case FSID_NUM: 109 fsidv[0] = fsid; 110 break; 111 case FSID_MAJOR_MINOR: 112 fsidv[0] = (__force __u32)htonl(MAJOR(dev)); 113 fsidv[1] = (__force __u32)htonl(MINOR(dev)); 114 fsidv[2] = ino_t_to_u32(ino); 115 break; 116 117 case FSID_ENCODE_DEV: 118 fsidv[0] = new_encode_dev(dev); 119 fsidv[1] = ino_t_to_u32(ino); 120 break; 121 122 case FSID_UUID4_INUM: 123 /* 4 byte fsid and inode number */ 124 up = (u32*)uuid; 125 fsidv[0] = ino_t_to_u32(ino); 126 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3]; 127 break; 128 129 case FSID_UUID8: 130 /* 8 byte fsid */ 131 up = (u32*)uuid; 132 fsidv[0] = up[0] ^ up[2]; 133 fsidv[1] = up[1] ^ up[3]; 134 break; 135 136 case FSID_UUID16: 137 /* 16 byte fsid - NFSv3+ only */ 138 memcpy(fsidv, uuid, 16); 139 break; 140 141 case FSID_UUID16_INUM: 142 /* 8 byte inode and 16 byte fsid */ 143 *(u64*)fsidv = (u64)ino; 144 memcpy(fsidv+2, uuid, 16); 145 break; 146 default: BUG(); 147 } 148 } 149 150 static inline int key_len(int type) 151 { 152 switch(type) { 153 case FSID_DEV: return 8; 154 case FSID_NUM: return 4; 155 case FSID_MAJOR_MINOR: return 12; 156 case FSID_ENCODE_DEV: return 8; 157 case FSID_UUID4_INUM: return 8; 158 case FSID_UUID8: return 8; 159 case FSID_UUID16: return 16; 160 case FSID_UUID16_INUM: return 24; 161 default: return 0; 162 } 163 } 164 165 /* 166 * Shorthand for dprintk()'s 167 */ 168 extern char * SVCFH_fmt(struct svc_fh *fhp); 169 170 /* 171 * Function prototypes 172 */ 173 __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int); 174 __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); 175 __be32 fh_update(struct svc_fh *); 176 void fh_put(struct svc_fh *); 177 178 static __inline__ struct svc_fh * 179 fh_copy(struct svc_fh *dst, struct svc_fh *src) 180 { 181 WARN_ON(src->fh_dentry || src->fh_locked); 182 183 *dst = *src; 184 return dst; 185 } 186 187 static inline void 188 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src) 189 { 190 dst->fh_size = src->fh_size; 191 memcpy(&dst->fh_base, &src->fh_base, src->fh_size); 192 } 193 194 static __inline__ struct svc_fh * 195 fh_init(struct svc_fh *fhp, int maxsize) 196 { 197 memset(fhp, 0, sizeof(*fhp)); 198 fhp->fh_maxsize = maxsize; 199 return fhp; 200 } 201 202 static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2) 203 { 204 if (fh1->fh_size != fh2->fh_size) 205 return false; 206 if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0) 207 return false; 208 return true; 209 } 210 211 static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2) 212 { 213 if (fh1->fh_fsid_type != fh2->fh_fsid_type) 214 return false; 215 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0) 216 return false; 217 return true; 218 } 219 220 #ifdef CONFIG_CRC32 221 /** 222 * knfsd_fh_hash - calculate the crc32 hash for the filehandle 223 * @fh - pointer to filehandle 224 * 225 * returns a crc32 hash for the filehandle that is compatible with 226 * the one displayed by "wireshark". 227 */ 228 229 static inline u32 230 knfsd_fh_hash(struct knfsd_fh *fh) 231 { 232 return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size); 233 } 234 #else 235 static inline u32 236 knfsd_fh_hash(struct knfsd_fh *fh) 237 { 238 return 0; 239 } 240 #endif 241 242 #ifdef CONFIG_NFSD_V3 243 /* 244 * The wcc data stored in current_fh should be cleared 245 * between compound ops. 246 */ 247 static inline void 248 fh_clear_wcc(struct svc_fh *fhp) 249 { 250 fhp->fh_post_saved = false; 251 fhp->fh_pre_saved = false; 252 } 253 254 /* 255 * We could use i_version alone as the change attribute. However, 256 * i_version can go backwards after a reboot. On its own that doesn't 257 * necessarily cause a problem, but if i_version goes backwards and then 258 * is incremented again it could reuse a value that was previously used 259 * before boot, and a client who queried the two values might 260 * incorrectly assume nothing changed. 261 * 262 * By using both ctime and the i_version counter we guarantee that as 263 * long as time doesn't go backwards we never reuse an old value. 264 */ 265 static inline u64 nfsd4_change_attribute(struct kstat *stat, 266 struct inode *inode) 267 { 268 if (inode->i_sb->s_export_op->fetch_iversion) 269 return inode->i_sb->s_export_op->fetch_iversion(inode); 270 else if (IS_I_VERSION(inode)) { 271 u64 chattr; 272 273 chattr = stat->ctime.tv_sec; 274 chattr <<= 30; 275 chattr += stat->ctime.tv_nsec; 276 chattr += inode_query_iversion(inode); 277 return chattr; 278 } else 279 return time_to_chattr(&stat->ctime); 280 } 281 282 extern void fill_pre_wcc(struct svc_fh *fhp); 283 extern void fill_post_wcc(struct svc_fh *fhp); 284 #else 285 #define fh_clear_wcc(ignored) 286 #define fill_pre_wcc(ignored) 287 #define fill_post_wcc(notused) 288 #endif /* CONFIG_NFSD_V3 */ 289 290 291 /* 292 * Lock a file handle/inode 293 * NOTE: both fh_lock and fh_unlock are done "by hand" in 294 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once 295 * so, any changes here should be reflected there. 296 */ 297 298 static inline void 299 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass) 300 { 301 struct dentry *dentry = fhp->fh_dentry; 302 struct inode *inode; 303 304 BUG_ON(!dentry); 305 306 if (fhp->fh_locked) { 307 printk(KERN_WARNING "fh_lock: %pd2 already locked!\n", 308 dentry); 309 return; 310 } 311 312 inode = d_inode(dentry); 313 inode_lock_nested(inode, subclass); 314 fill_pre_wcc(fhp); 315 fhp->fh_locked = true; 316 } 317 318 static inline void 319 fh_lock(struct svc_fh *fhp) 320 { 321 fh_lock_nested(fhp, I_MUTEX_NORMAL); 322 } 323 324 /* 325 * Unlock a file handle/inode 326 */ 327 static inline void 328 fh_unlock(struct svc_fh *fhp) 329 { 330 if (fhp->fh_locked) { 331 fill_post_wcc(fhp); 332 inode_unlock(d_inode(fhp->fh_dentry)); 333 fhp->fh_locked = false; 334 } 335 } 336 337 #endif /* _LINUX_NFSD_NFSFH_H */ 338