1 /* 2 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 3 * 4 * This file describes the layout of the file handles as passed 5 * over the wire. 6 */ 7 #ifndef _LINUX_NFSD_NFSFH_H 8 #define _LINUX_NFSD_NFSFH_H 9 10 #include <linux/crc32.h> 11 #include <linux/sunrpc/svc.h> 12 #include <uapi/linux/nfsd/nfsfh.h> 13 14 static inline __u32 ino_t_to_u32(ino_t ino) 15 { 16 return (__u32) ino; 17 } 18 19 static inline ino_t u32_to_ino_t(__u32 uino) 20 { 21 return (ino_t) uino; 22 } 23 24 /* 25 * This is the internal representation of an NFS handle used in knfsd. 26 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3. 27 */ 28 typedef struct svc_fh { 29 struct knfsd_fh fh_handle; /* FH data */ 30 int fh_maxsize; /* max size for fh_handle */ 31 struct dentry * fh_dentry; /* validated dentry */ 32 struct svc_export * fh_export; /* export pointer */ 33 34 bool fh_locked; /* inode locked by us */ 35 bool fh_want_write; /* remount protection taken */ 36 37 #ifdef CONFIG_NFSD_V3 38 bool fh_post_saved; /* post-op attrs saved */ 39 bool fh_pre_saved; /* pre-op attrs saved */ 40 41 /* Pre-op attributes saved during fh_lock */ 42 __u64 fh_pre_size; /* size before operation */ 43 struct timespec fh_pre_mtime; /* mtime before oper */ 44 struct timespec fh_pre_ctime; /* ctime before oper */ 45 /* 46 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode) 47 * to find out if it is valid. 48 */ 49 u64 fh_pre_change; 50 51 /* Post-op attributes saved in fh_unlock */ 52 struct kstat fh_post_attr; /* full attrs after operation */ 53 u64 fh_post_change; /* nfsv4 change; see above */ 54 #endif /* CONFIG_NFSD_V3 */ 55 56 } svc_fh; 57 58 enum nfsd_fsid { 59 FSID_DEV = 0, 60 FSID_NUM, 61 FSID_MAJOR_MINOR, 62 FSID_ENCODE_DEV, 63 FSID_UUID4_INUM, 64 FSID_UUID8, 65 FSID_UUID16, 66 FSID_UUID16_INUM, 67 }; 68 69 enum fsid_source { 70 FSIDSOURCE_DEV, 71 FSIDSOURCE_FSID, 72 FSIDSOURCE_UUID, 73 }; 74 extern enum fsid_source fsid_source(struct svc_fh *fhp); 75 76 77 /* 78 * This might look a little large to "inline" but in all calls except 79 * one, 'vers' is constant so moste of the function disappears. 80 * 81 * In some cases the values are considered to be host endian and in 82 * others, net endian. fsidv is always considered to be u32 as the 83 * callers don't know which it will be. So we must use __force to keep 84 * sparse from complaining. Since these values are opaque to the 85 * client, that shouldn't be a problem. 86 */ 87 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino, 88 u32 fsid, unsigned char *uuid) 89 { 90 u32 *up; 91 switch(vers) { 92 case FSID_DEV: 93 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) | 94 MINOR(dev)); 95 fsidv[1] = ino_t_to_u32(ino); 96 break; 97 case FSID_NUM: 98 fsidv[0] = fsid; 99 break; 100 case FSID_MAJOR_MINOR: 101 fsidv[0] = (__force __u32)htonl(MAJOR(dev)); 102 fsidv[1] = (__force __u32)htonl(MINOR(dev)); 103 fsidv[2] = ino_t_to_u32(ino); 104 break; 105 106 case FSID_ENCODE_DEV: 107 fsidv[0] = new_encode_dev(dev); 108 fsidv[1] = ino_t_to_u32(ino); 109 break; 110 111 case FSID_UUID4_INUM: 112 /* 4 byte fsid and inode number */ 113 up = (u32*)uuid; 114 fsidv[0] = ino_t_to_u32(ino); 115 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3]; 116 break; 117 118 case FSID_UUID8: 119 /* 8 byte fsid */ 120 up = (u32*)uuid; 121 fsidv[0] = up[0] ^ up[2]; 122 fsidv[1] = up[1] ^ up[3]; 123 break; 124 125 case FSID_UUID16: 126 /* 16 byte fsid - NFSv3+ only */ 127 memcpy(fsidv, uuid, 16); 128 break; 129 130 case FSID_UUID16_INUM: 131 /* 8 byte inode and 16 byte fsid */ 132 *(u64*)fsidv = (u64)ino; 133 memcpy(fsidv+2, uuid, 16); 134 break; 135 default: BUG(); 136 } 137 } 138 139 static inline int key_len(int type) 140 { 141 switch(type) { 142 case FSID_DEV: return 8; 143 case FSID_NUM: return 4; 144 case FSID_MAJOR_MINOR: return 12; 145 case FSID_ENCODE_DEV: return 8; 146 case FSID_UUID4_INUM: return 8; 147 case FSID_UUID8: return 8; 148 case FSID_UUID16: return 16; 149 case FSID_UUID16_INUM: return 24; 150 default: return 0; 151 } 152 } 153 154 /* 155 * Shorthand for dprintk()'s 156 */ 157 extern char * SVCFH_fmt(struct svc_fh *fhp); 158 159 /* 160 * Function prototypes 161 */ 162 __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int); 163 __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); 164 __be32 fh_update(struct svc_fh *); 165 void fh_put(struct svc_fh *); 166 167 static __inline__ struct svc_fh * 168 fh_copy(struct svc_fh *dst, struct svc_fh *src) 169 { 170 WARN_ON(src->fh_dentry || src->fh_locked); 171 172 *dst = *src; 173 return dst; 174 } 175 176 static inline void 177 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src) 178 { 179 dst->fh_size = src->fh_size; 180 memcpy(&dst->fh_base, &src->fh_base, src->fh_size); 181 } 182 183 static __inline__ struct svc_fh * 184 fh_init(struct svc_fh *fhp, int maxsize) 185 { 186 memset(fhp, 0, sizeof(*fhp)); 187 fhp->fh_maxsize = maxsize; 188 return fhp; 189 } 190 191 static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2) 192 { 193 if (fh1->fh_size != fh2->fh_size) 194 return false; 195 if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0) 196 return false; 197 return true; 198 } 199 200 static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2) 201 { 202 if (fh1->fh_fsid_type != fh2->fh_fsid_type) 203 return false; 204 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0) 205 return false; 206 return true; 207 } 208 209 #ifdef CONFIG_CRC32 210 /** 211 * knfsd_fh_hash - calculate the crc32 hash for the filehandle 212 * @fh - pointer to filehandle 213 * 214 * returns a crc32 hash for the filehandle that is compatible with 215 * the one displayed by "wireshark". 216 */ 217 218 static inline u32 219 knfsd_fh_hash(struct knfsd_fh *fh) 220 { 221 return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size); 222 } 223 #else 224 static inline u32 225 knfsd_fh_hash(struct knfsd_fh *fh) 226 { 227 return 0; 228 } 229 #endif 230 231 #ifdef CONFIG_NFSD_V3 232 /* 233 * The wcc data stored in current_fh should be cleared 234 * between compound ops. 235 */ 236 static inline void 237 fh_clear_wcc(struct svc_fh *fhp) 238 { 239 fhp->fh_post_saved = false; 240 fhp->fh_pre_saved = false; 241 } 242 243 /* 244 * We could use i_version alone as the change attribute. However, 245 * i_version can go backwards after a reboot. On its own that doesn't 246 * necessarily cause a problem, but if i_version goes backwards and then 247 * is incremented again it could reuse a value that was previously used 248 * before boot, and a client who queried the two values might 249 * incorrectly assume nothing changed. 250 * 251 * By using both ctime and the i_version counter we guarantee that as 252 * long as time doesn't go backwards we never reuse an old value. 253 */ 254 static inline u64 nfsd4_change_attribute(struct inode *inode) 255 { 256 u64 chattr; 257 258 chattr = inode->i_ctime.tv_sec; 259 chattr <<= 30; 260 chattr += inode->i_ctime.tv_nsec; 261 chattr += inode->i_version; 262 return chattr; 263 } 264 265 /* 266 * Fill in the pre_op attr for the wcc data 267 */ 268 static inline void 269 fill_pre_wcc(struct svc_fh *fhp) 270 { 271 struct inode *inode; 272 273 inode = d_inode(fhp->fh_dentry); 274 if (!fhp->fh_pre_saved) { 275 fhp->fh_pre_mtime = inode->i_mtime; 276 fhp->fh_pre_ctime = inode->i_ctime; 277 fhp->fh_pre_size = inode->i_size; 278 fhp->fh_pre_change = nfsd4_change_attribute(inode); 279 fhp->fh_pre_saved = true; 280 } 281 } 282 283 extern void fill_post_wcc(struct svc_fh *); 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