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 /* This might look a little large to "inline" but in all calls except
  77  * one, 'vers' is constant so moste of the function disappears.
  78  */
  79 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
  80                            u32 fsid, unsigned char *uuid)
  81 {
  82         u32 *up;
  83         switch(vers) {
  84         case FSID_DEV:
  85                 fsidv[0] = htonl((MAJOR(dev)<<16) |
  86                                  MINOR(dev));
  87                 fsidv[1] = ino_t_to_u32(ino);
  88                 break;
  89         case FSID_NUM:
  90                 fsidv[0] = fsid;
  91                 break;
  92         case FSID_MAJOR_MINOR:
  93                 fsidv[0] = htonl(MAJOR(dev));
  94                 fsidv[1] = htonl(MINOR(dev));
  95                 fsidv[2] = ino_t_to_u32(ino);
  96                 break;
  97
  98         case FSID_ENCODE_DEV:
  99                 fsidv[0] = new_encode_dev(dev);
 100                 fsidv[1] = ino_t_to_u32(ino);
 101                 break;
 102
 103         case FSID_UUID4_INUM:
 104                 /* 4 byte fsid and inode number */
 105                 up = (u32*)uuid;
 106                 fsidv[0] = ino_t_to_u32(ino);
 107                 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
 108                 break;
 109
 110         case FSID_UUID8:
 111                 /* 8 byte fsid  */
 112                 up = (u32*)uuid;
 113                 fsidv[0] = up[0] ^ up[2];
 114                 fsidv[1] = up[1] ^ up[3];
 115                 break;
 116
 117         case FSID_UUID16:
 118                 /* 16 byte fsid - NFSv3+ only */
 119                 memcpy(fsidv, uuid, 16);
 120                 break;
 121
 122         case FSID_UUID16_INUM:
 123                 /* 8 byte inode and 16 byte fsid */
 124                 *(u64*)fsidv = (u64)ino;
 125                 memcpy(fsidv+2, uuid, 16);
 126                 break;
 127         default: BUG();
 128         }
 129 }
 130
 131 static inline int key_len(int type)
 132 {
 133         switch(type) {
 134         case FSID_DEV:          return 8;
 135         case FSID_NUM:          return 4;
 136         case FSID_MAJOR_MINOR:  return 12;
 137         case FSID_ENCODE_DEV:   return 8;
 138         case FSID_UUID4_INUM:   return 8;
 139         case FSID_UUID8:        return 8;
 140         case FSID_UUID16:       return 16;
 141         case FSID_UUID16_INUM:  return 24;
 142         default: return 0;
 143         }
 144 }
 145
 146 /*
 147  * Shorthand for dprintk()'s
 148  */
 149 extern char * SVCFH_fmt(struct svc_fh *fhp);
 150
 151 /*
 152  * Function prototypes
 153  */
 154 __be32  fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
 155 __be32  fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
 156 __be32  fh_update(struct svc_fh *);
 157 void    fh_put(struct svc_fh *);
 158
 159 static __inline__ struct svc_fh *
 160 fh_copy(struct svc_fh *dst, struct svc_fh *src)
 161 {
 162         WARN_ON(src->fh_dentry || src->fh_locked);
 163
 164         *dst = *src;
 165         return dst;
 166 }
 167
 168 static inline void
 169 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
 170 {
 171         dst->fh_size = src->fh_size;
 172         memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
 173 }
 174
 175 static __inline__ struct svc_fh *
 176 fh_init(struct svc_fh *fhp, int maxsize)
 177 {
 178         memset(fhp, 0, sizeof(*fhp));
 179         fhp->fh_maxsize = maxsize;
 180         return fhp;
 181 }
 182
 183 #ifdef CONFIG_NFSD_V3
 184 /*
 185  * The wcc data stored in current_fh should be cleared
 186  * between compound ops.
 187  */
 188 static inline void
 189 fh_clear_wcc(struct svc_fh *fhp)
 190 {
 191         fhp->fh_post_saved = 0;
 192         fhp->fh_pre_saved = 0;
 193 }
 194
 195 /*
 196  * Fill in the pre_op attr for the wcc data
 197  */
 198 static inline void
 199 fill_pre_wcc(struct svc_fh *fhp)
 200 {
 201         struct inode    *inode;
 202
 203         inode = fhp->fh_dentry->d_inode;
 204         if (!fhp->fh_pre_saved) {
 205                 fhp->fh_pre_mtime = inode->i_mtime;
 206                 fhp->fh_pre_ctime = inode->i_ctime;
 207                 fhp->fh_pre_size  = inode->i_size;
 208                 fhp->fh_pre_change = inode->i_version;
 209                 fhp->fh_pre_saved = 1;
 210         }
 211 }
 212
 213 extern void fill_post_wcc(struct svc_fh *);
 214 #else
 215 #define fh_clear_wcc(ignored)
 216 #define fill_pre_wcc(ignored)
 217 #define fill_post_wcc(notused)
 218 #endif /* CONFIG_NFSD_V3 */
 219
 220
 221 /*
 222  * Lock a file handle/inode
 223  * NOTE: both fh_lock and fh_unlock are done "by hand" in
 224  * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
 225  * so, any changes here should be reflected there.
 226  */
 227
 228 static inline void
 229 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
 230 {
 231         struct dentry   *dentry = fhp->fh_dentry;
 232         struct inode    *inode;
 233
 234         BUG_ON(!dentry);
 235
 236         if (fhp->fh_locked) {
 237                 printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
 238                         dentry);
 239                 return;
 240         }
 241
 242         inode = dentry->d_inode;
 243         mutex_lock_nested(&inode->i_mutex, subclass);
 244         fill_pre_wcc(fhp);
 245         fhp->fh_locked = 1;
 246 }
 247
 248 static inline void
 249 fh_lock(struct svc_fh *fhp)
 250 {
 251         fh_lock_nested(fhp, I_MUTEX_NORMAL);
 252 }
 253
 254 /*
 255  * Unlock a file handle/inode
 256  */
 257 static inline void
 258 fh_unlock(struct svc_fh *fhp)
 259 {
 260         if (fhp->fh_locked) {
 261                 fill_post_wcc(fhp);
 262                 mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
 263                 fhp->fh_locked = 0;
 264         }
 265 }
 266
 267 #endif /* _LINUX_NFSD_NFSFH_H */