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