fs/nfsd/nfsfh.h

   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/sunrpc/svc.h>
  11 #include <uapi/linux/nfsd/nfsfh.h>
  12
  13 static inline __u32 ino_t_to_u32(ino_t ino)
  14 {
  15         return (__u32) ino;
  16 }
  17
  18 static inline ino_t u32_to_ino_t(__u32 uino)
  19 {
  20         return (ino_t) uino;
  21 }
  22
  23 /*
  24  * This is the internal representation of an NFS handle used in knfsd.
  25  * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
  26  */
  27 typedef struct svc_fh {
  28         struct knfsd_fh         fh_handle;      /* FH data */
  29         struct dentry *         fh_dentry;      /* validated dentry */
  30         struct svc_export *     fh_export;      /* export pointer */
  31         int                     fh_maxsize;     /* max size for fh_handle */
  32
  33         unsigned char           fh_locked;      /* inode locked by us */
  34         unsigned char           fh_want_write;  /* remount protection taken */
  35
  36 #ifdef CONFIG_NFSD_V3
  37         unsigned char           fh_post_saved;  /* post-op attrs saved */
  38         unsigned char           fh_pre_saved;   /* pre-op attrs saved */
  39
  40         /* Pre-op attributes saved during fh_lock */
  41         __u64                   fh_pre_size;    /* size before operation */
  42         struct timespec         fh_pre_mtime;   /* mtime before oper */
  43         struct timespec         fh_pre_ctime;   /* ctime before oper */
  44         /*
  45          * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
  46          *  to find out if it is valid.
  47          */
  48         u64                     fh_pre_change;
  49
  50         /* Post-op attributes saved in fh_unlock */
  51         struct kstat            fh_post_attr;   /* full attrs after operation */
  52         u64                     fh_post_change; /* nfsv4 change; see above */
  53 #endif /* CONFIG_NFSD_V3 */
  54
  55 } svc_fh;
  56
  57 enum nfsd_fsid {
  58         FSID_DEV = 0,
  59         FSID_NUM,
  60         FSID_MAJOR_MINOR,
  61         FSID_ENCODE_DEV,
  62         FSID_UUID4_INUM,
  63         FSID_UUID8,
  64         FSID_UUID16,
  65         FSID_UUID16_INUM,
  66 };
  67
  68 enum fsid_source {
  69         FSIDSOURCE_DEV,
  70         FSIDSOURCE_FSID,
  71         FSIDSOURCE_UUID,
  72 };
  73 extern enum fsid_source fsid_source(struct svc_fh *fhp);
  74
  75
  76 /*
  77  * This might look a little large to "inline" but in all calls except
  78  * one, 'vers' is constant so moste of the function disappears.
  79  *
  80  * In some cases the values are considered to be host endian and in
  81  * others, net endian. fsidv is always considered to be u32 as the
  82  * callers don't know which it will be. So we must use __force to keep
  83  * sparse from complaining. Since these values are opaque to the
  84  * client, that shouldn't be a problem.
  85  */
  86 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
  87                            u32 fsid, unsigned char *uuid)
  88 {
  89         u32 *up;
  90         switch(vers) {
  91         case FSID_DEV:
  92                 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
  93                                  MINOR(dev));
  94                 fsidv[1] = ino_t_to_u32(ino);
  95                 break;
  96         case FSID_NUM:
  97                 fsidv[0] = fsid;
  98                 break;
  99         case FSID_MAJOR_MINOR:
 100                 fsidv[0] = (__force __u32)htonl(MAJOR(dev));
 101                 fsidv[1] = (__force __u32)htonl(MINOR(dev));
 102                 fsidv[2] = ino_t_to_u32(ino);
 103                 break;
 104
 105         case FSID_ENCODE_DEV:
 106                 fsidv[0] = new_encode_dev(dev);
 107                 fsidv[1] = ino_t_to_u32(ino);
 108                 break;
 109
 110         case FSID_UUID4_INUM:
 111                 /* 4 byte fsid and inode number */
 112                 up = (u32*)uuid;
 113                 fsidv[0] = ino_t_to_u32(ino);
 114                 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
 115                 break;
 116
 117         case FSID_UUID8:
 118                 /* 8 byte fsid  */
 119                 up = (u32*)uuid;
 120                 fsidv[0] = up[0] ^ up[2];
 121                 fsidv[1] = up[1] ^ up[3];
 122                 break;
 123
 124         case FSID_UUID16:
 125                 /* 16 byte fsid - NFSv3+ only */
 126                 memcpy(fsidv, uuid, 16);
 127                 break;
 128
 129         case FSID_UUID16_INUM:
 130                 /* 8 byte inode and 16 byte fsid */
 131                 *(u64*)fsidv = (u64)ino;
 132                 memcpy(fsidv+2, uuid, 16);
 133                 break;
 134         default: BUG();
 135         }
 136 }
 137
 138 static inline int key_len(int type)
 139 {
 140         switch(type) {
 141         case FSID_DEV:          return 8;
 142         case FSID_NUM:          return 4;
 143         case FSID_MAJOR_MINOR:  return 12;
 144         case FSID_ENCODE_DEV:   return 8;
 145         case FSID_UUID4_INUM:   return 8;
 146         case FSID_UUID8:        return 8;
 147         case FSID_UUID16:       return 16;
 148         case FSID_UUID16_INUM:  return 24;
 149         default: return 0;
 150         }
 151 }
 152
 153 /*
 154  * Shorthand for dprintk()'s
 155  */
 156 extern char * SVCFH_fmt(struct svc_fh *fhp);
 157
 158 /*
 159  * Function prototypes
 160  */
 161 __be32  fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
 162 __be32  fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
 163 __be32  fh_update(struct svc_fh *);
 164 void    fh_put(struct svc_fh *);
 165
 166 static __inline__ struct svc_fh *
 167 fh_copy(struct svc_fh *dst, struct svc_fh *src)
 168 {
 169         WARN_ON(src->fh_dentry || src->fh_locked);
 170
 171         *dst = *src;
 172         return dst;
 173 }
 174
 175 static inline void
 176 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
 177 {
 178         dst->fh_size = src->fh_size;
 179         memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
 180 }
 181
 182 static __inline__ struct svc_fh *
 183 fh_init(struct svc_fh *fhp, int maxsize)
 184 {
 185         memset(fhp, 0, sizeof(*fhp));
 186         fhp->fh_maxsize = maxsize;
 187         return fhp;
 188 }
 189
 190 static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
 191 {
 192         if (fh1->fh_size != fh2->fh_size)
 193                 return false;
 194         if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
 195                 return false;
 196         return true;
 197 }
 198
 199 static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
 200 {
 201         if (fh1->fh_fsid_type != fh2->fh_fsid_type)
 202                 return false;
 203         if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
 204                 return false;
 205         return true;
 206 }
 207
 208 #ifdef CONFIG_NFSD_V3
 209 /*
 210  * The wcc data stored in current_fh should be cleared
 211  * between compound ops.
 212  */
 213 static inline void
 214 fh_clear_wcc(struct svc_fh *fhp)
 215 {
 216         fhp->fh_post_saved = 0;
 217         fhp->fh_pre_saved = 0;
 218 }
 219
 220 /*
 221  * Fill in the pre_op attr for the wcc data
 222  */
 223 static inline void
 224 fill_pre_wcc(struct svc_fh *fhp)
 225 {
 226         struct inode    *inode;
 227
 228         inode = d_inode(fhp->fh_dentry);
 229         if (!fhp->fh_pre_saved) {
 230                 fhp->fh_pre_mtime = inode->i_mtime;
 231                 fhp->fh_pre_ctime = inode->i_ctime;
 232                 fhp->fh_pre_size  = inode->i_size;
 233                 fhp->fh_pre_change = inode->i_version;
 234                 fhp->fh_pre_saved = 1;
 235         }
 236 }
 237
 238 extern void fill_post_wcc(struct svc_fh *);
 239 #else
 240 #define fh_clear_wcc(ignored)
 241 #define fill_pre_wcc(ignored)
 242 #define fill_post_wcc(notused)
 243 #endif /* CONFIG_NFSD_V3 */
 244
 245
 246 /*
 247  * Lock a file handle/inode
 248  * NOTE: both fh_lock and fh_unlock are done "by hand" in
 249  * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
 250  * so, any changes here should be reflected there.
 251  */
 252
 253 static inline void
 254 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
 255 {
 256         struct dentry   *dentry = fhp->fh_dentry;
 257         struct inode    *inode;
 258
 259         BUG_ON(!dentry);
 260
 261         if (fhp->fh_locked) {
 262                 printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
 263                         dentry);
 264                 return;
 265         }
 266
 267         inode = d_inode(dentry);
 268         mutex_lock_nested(&inode->i_mutex, subclass);
 269         fill_pre_wcc(fhp);
 270         fhp->fh_locked = 1;
 271 }
 272
 273 static inline void
 274 fh_lock(struct svc_fh *fhp)
 275 {
 276         fh_lock_nested(fhp, I_MUTEX_NORMAL);
 277 }
 278
 279 /*
 280  * Unlock a file handle/inode
 281  */
 282 static inline void
 283 fh_unlock(struct svc_fh *fhp)
 284 {
 285         if (fhp->fh_locked) {
 286                 fill_post_wcc(fhp);
 287                 mutex_unlock(&d_inode(fhp->fh_dentry)->i_mutex);
 288                 fhp->fh_locked = 0;
 289         }
 290 }
 291
 292 #endif /* _LINUX_NFSD_NFSFH_H */