fs/nfs/inode.c

   1 /*
   2  *  linux/fs/nfs/inode.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs inode and superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/sched.h>
  19 #include <linux/time.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/string.h>
  23 #include <linux/stat.h>
  24 #include <linux/errno.h>
  25 #include <linux/unistd.h>
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/sunrpc/stats.h>
  28 #include <linux/sunrpc/metrics.h>
  29 #include <linux/nfs_fs.h>
  30 #include <linux/nfs_mount.h>
  31 #include <linux/nfs4_mount.h>
  32 #include <linux/lockd/bind.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/mount.h>
  35 #include <linux/nfs_idmap.h>
  36 #include <linux/vfs.h>
  37 #include <linux/inet.h>
  38 #include <linux/nfs_xdr.h>
  39 #include <linux/slab.h>
  40
  41 #include <asm/system.h>
  42 #include <asm/uaccess.h>
  43
  44 #include "nfs4_fs.h"
  45 #include "callback.h"
  46 #include "delegation.h"
  47 #include "iostat.h"
  48 #include "internal.h"
  49 #include "fscache.h"
  50 #include "dns_resolve.h"
  51 #include "pnfs.h"
  52
  53 #define NFSDBG_FACILITY         NFSDBG_VFS
  54
  55 #define NFS_64_BIT_INODE_NUMBERS_ENABLED        1
  56
  57 /* Default is to see 64-bit inode numbers */
  58 static int enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
  59
  60 static void nfs_invalidate_inode(struct inode *);
  61 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
  62
  63 static struct kmem_cache * nfs_inode_cachep;
  64
  65 static inline unsigned long
  66 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
  67 {
  68         return nfs_fileid_to_ino_t(fattr->fileid);
  69 }
  70
  71 /**
  72  * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
  73  * @word: long word containing the bit lock
  74  */
  75 int nfs_wait_bit_killable(void *word)
  76 {
  77         if (fatal_signal_pending(current))
  78                 return -ERESTARTSYS;
  79         schedule();
  80         return 0;
  81 }
  82
  83 /**
  84  * nfs_compat_user_ino64 - returns the user-visible inode number
  85  * @fileid: 64-bit fileid
  86  *
  87  * This function returns a 32-bit inode number if the boot parameter
  88  * nfs.enable_ino64 is zero.
  89  */
  90 u64 nfs_compat_user_ino64(u64 fileid)
  91 {
  92         int ino;
  93
  94         if (enable_ino64)
  95                 return fileid;
  96         ino = fileid;
  97         if (sizeof(ino) < sizeof(fileid))
  98                 ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
  99         return ino;
 100 }
 101
 102 static void nfs_clear_inode(struct inode *inode)
 103 {
 104         /*
 105          * The following should never happen...
 106          */
 107         BUG_ON(nfs_have_writebacks(inode));
 108         BUG_ON(!list_empty(&NFS_I(inode)->open_files));
 109         nfs_zap_acl_cache(inode);
 110         nfs_access_zap_cache(inode);
 111         nfs_fscache_release_inode_cookie(inode);
 112 }
 113
 114 void nfs_evict_inode(struct inode *inode)
 115 {
 116         truncate_inode_pages(&inode->i_data, 0);
 117         end_writeback(inode);
 118         nfs_clear_inode(inode);
 119 }
 120
 121 /**
 122  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
 123  */
 124 int nfs_sync_mapping(struct address_space *mapping)
 125 {
 126         int ret = 0;
 127
 128         if (mapping->nrpages != 0) {
 129                 unmap_mapping_range(mapping, 0, 0, 0);
 130                 ret = nfs_wb_all(mapping->host);
 131         }
 132         return ret;
 133 }
 134
 135 /*
 136  * Invalidate the local caches
 137  */
 138 static void nfs_zap_caches_locked(struct inode *inode)
 139 {
 140         struct nfs_inode *nfsi = NFS_I(inode);
 141         int mode = inode->i_mode;
 142
 143         nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
 144
 145         nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
 146         nfsi->attrtimeo_timestamp = jiffies;
 147
 148         memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
 149         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
 150                 nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
 151         else
 152                 nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
 153 }
 154
 155 void nfs_zap_caches(struct inode *inode)
 156 {
 157         spin_lock(&inode->i_lock);
 158         nfs_zap_caches_locked(inode);
 159         spin_unlock(&inode->i_lock);
 160 }
 161
 162 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
 163 {
 164         if (mapping->nrpages != 0) {
 165                 spin_lock(&inode->i_lock);
 166                 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
 167                 spin_unlock(&inode->i_lock);
 168         }
 169 }
 170
 171 void nfs_zap_acl_cache(struct inode *inode)
 172 {
 173         void (*clear_acl_cache)(struct inode *);
 174
 175         clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
 176         if (clear_acl_cache != NULL)
 177                 clear_acl_cache(inode);
 178         spin_lock(&inode->i_lock);
 179         NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
 180         spin_unlock(&inode->i_lock);
 181 }
 182
 183 void nfs_invalidate_atime(struct inode *inode)
 184 {
 185         spin_lock(&inode->i_lock);
 186         NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
 187         spin_unlock(&inode->i_lock);
 188 }
 189
 190 /*
 191  * Invalidate, but do not unhash, the inode.
 192  * NB: must be called with inode->i_lock held!
 193  */
 194 static void nfs_invalidate_inode(struct inode *inode)
 195 {
 196         set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 197         nfs_zap_caches_locked(inode);
 198 }
 199
 200 struct nfs_find_desc {
 201         struct nfs_fh           *fh;
 202         struct nfs_fattr        *fattr;
 203 };
 204
 205 /*
 206  * In NFSv3 we can have 64bit inode numbers. In order to support
 207  * this, and re-exported directories (also seen in NFSv2)
 208  * we are forced to allow 2 different inodes to have the same
 209  * i_ino.
 210  */
 211 static int
 212 nfs_find_actor(struct inode *inode, void *opaque)
 213 {
 214         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
 215         struct nfs_fh           *fh = desc->fh;
 216         struct nfs_fattr        *fattr = desc->fattr;
 217
 218         if (NFS_FILEID(inode) != fattr->fileid)
 219                 return 0;
 220         if (nfs_compare_fh(NFS_FH(inode), fh))
 221                 return 0;
 222         if (is_bad_inode(inode) || NFS_STALE(inode))
 223                 return 0;
 224         return 1;
 225 }
 226
 227 static int
 228 nfs_init_locked(struct inode *inode, void *opaque)
 229 {
 230         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
 231         struct nfs_fattr        *fattr = desc->fattr;
 232
 233         set_nfs_fileid(inode, fattr->fileid);
 234         nfs_copy_fh(NFS_FH(inode), desc->fh);
 235         return 0;
 236 }
 237
 238 /*
 239  * This is our front-end to iget that looks up inodes by file handle
 240  * instead of inode number.
 241  */
 242 struct inode *
 243 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
 244 {
 245         struct nfs_find_desc desc = {
 246                 .fh     = fh,
 247                 .fattr  = fattr
 248         };
 249         struct inode *inode = ERR_PTR(-ENOENT);
 250         unsigned long hash;
 251
 252         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
 253                 goto out_no_inode;
 254         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
 255                 goto out_no_inode;
 256
 257         hash = nfs_fattr_to_ino_t(fattr);
 258
 259         inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
 260         if (inode == NULL) {
 261                 inode = ERR_PTR(-ENOMEM);
 262                 goto out_no_inode;
 263         }
 264
 265         if (inode->i_state & I_NEW) {
 266                 struct nfs_inode *nfsi = NFS_I(inode);
 267                 unsigned long now = jiffies;
 268
 269                 /* We set i_ino for the few things that still rely on it,
 270                  * such as stat(2) */
 271                 inode->i_ino = hash;
 272
 273                 /* We can't support update_atime(), since the server will reset it */
 274                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 275                 inode->i_mode = fattr->mode;
 276                 if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
 277                                 && nfs_server_capable(inode, NFS_CAP_MODE))
 278                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 279                                 | NFS_INO_INVALID_ACCESS
 280                                 | NFS_INO_INVALID_ACL;
 281                 /* Why so? Because we want revalidate for devices/FIFOs, and
 282                  * that's precisely what we have in nfs_file_inode_operations.
 283                  */
 284                 inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
 285                 if (S_ISREG(inode->i_mode)) {
 286                         inode->i_fop = &nfs_file_operations;
 287                         inode->i_data.a_ops = &nfs_file_aops;
 288                         inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
 289                 } else if (S_ISDIR(inode->i_mode)) {
 290                         inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
 291                         inode->i_fop = &nfs_dir_operations;
 292                         inode->i_data.a_ops = &nfs_dir_aops;
 293                         if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS))
 294                                 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
 295                         /* Deal with crossing mountpoints */
 296                         if ((fattr->valid & NFS_ATTR_FATTR_FSID)
 297                                         && !nfs_fsid_equal(&NFS_SB(sb)->fsid, &fattr->fsid)) {
 298                                 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
 299                                         inode->i_op = &nfs_referral_inode_operations;
 300                                 else
 301                                         inode->i_op = &nfs_mountpoint_inode_operations;
 302                                 inode->i_fop = NULL;
 303                                 inode->i_flags |= S_AUTOMOUNT;
 304                         }
 305                 } else if (S_ISLNK(inode->i_mode))
 306                         inode->i_op = &nfs_symlink_inode_operations;
 307                 else
 308                         init_special_inode(inode, inode->i_mode, fattr->rdev);
 309
 310                 memset(&inode->i_atime, 0, sizeof(inode->i_atime));
 311                 memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
 312                 memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
 313                 nfsi->change_attr = 0;
 314                 inode->i_size = 0;
 315                 inode->i_nlink = 0;
 316                 inode->i_uid = -2;
 317                 inode->i_gid = -2;
 318                 inode->i_blocks = 0;
 319                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
 320
 321                 nfsi->read_cache_jiffies = fattr->time_start;
 322                 nfsi->attr_gencount = fattr->gencount;
 323                 if (fattr->valid & NFS_ATTR_FATTR_ATIME)
 324                         inode->i_atime = fattr->atime;
 325                 else if (nfs_server_capable(inode, NFS_CAP_ATIME))
 326                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
 327                 if (fattr->valid & NFS_ATTR_FATTR_MTIME)
 328                         inode->i_mtime = fattr->mtime;
 329                 else if (nfs_server_capable(inode, NFS_CAP_MTIME))
 330                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 331                                 | NFS_INO_INVALID_DATA;
 332                 if (fattr->valid & NFS_ATTR_FATTR_CTIME)
 333                         inode->i_ctime = fattr->ctime;
 334                 else if (nfs_server_capable(inode, NFS_CAP_CTIME))
 335                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 336                                 | NFS_INO_INVALID_ACCESS
 337                                 | NFS_INO_INVALID_ACL;
 338                 if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
 339                         nfsi->change_attr = fattr->change_attr;
 340                 else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
 341                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 342                                 | NFS_INO_INVALID_DATA;
 343                 if (fattr->valid & NFS_ATTR_FATTR_SIZE)
 344                         inode->i_size = nfs_size_to_loff_t(fattr->size);
 345                 else
 346                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 347                                 | NFS_INO_INVALID_DATA
 348                                 | NFS_INO_REVAL_PAGECACHE;
 349                 if (fattr->valid & NFS_ATTR_FATTR_NLINK)
 350                         inode->i_nlink = fattr->nlink;
 351                 else if (nfs_server_capable(inode, NFS_CAP_NLINK))
 352                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
 353                 if (fattr->valid & NFS_ATTR_FATTR_OWNER)
 354                         inode->i_uid = fattr->uid;
 355                 else if (nfs_server_capable(inode, NFS_CAP_OWNER))
 356                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 357                                 | NFS_INO_INVALID_ACCESS
 358                                 | NFS_INO_INVALID_ACL;
 359                 if (fattr->valid & NFS_ATTR_FATTR_GROUP)
 360                         inode->i_gid = fattr->gid;
 361                 else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
 362                         nfsi->cache_validity |= NFS_INO_INVALID_ATTR
 363                                 | NFS_INO_INVALID_ACCESS
 364                                 | NFS_INO_INVALID_ACL;
 365                 if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
 366                         inode->i_blocks = fattr->du.nfs2.blocks;
 367                 if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
 368                         /*
 369                          * report the blocks in 512byte units
 370                          */
 371                         inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
 372                 }
 373                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
 374                 nfsi->attrtimeo_timestamp = now;
 375                 nfsi->access_cache = RB_ROOT;
 376
 377                 nfs_fscache_init_inode_cookie(inode);
 378
 379                 unlock_new_inode(inode);
 380         } else
 381                 nfs_refresh_inode(inode, fattr);
 382         dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
 383                 inode->i_sb->s_id,
 384                 (long long)NFS_FILEID(inode),
 385                 atomic_read(&inode->i_count));
 386
 387 out:
 388         return inode;
 389
 390 out_no_inode:
 391         dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
 392         goto out;
 393 }
 394
 395 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE)
 396
 397 int
 398 nfs_setattr(struct dentry *dentry, struct iattr *attr)
 399 {
 400         struct inode *inode = dentry->d_inode;
 401         struct nfs_fattr *fattr;
 402         int error = -ENOMEM;
 403
 404         nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
 405
 406         /* skip mode change if it's just for clearing setuid/setgid */
 407         if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
 408                 attr->ia_valid &= ~ATTR_MODE;
 409
 410         if (attr->ia_valid & ATTR_SIZE) {
 411                 if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
 412                         attr->ia_valid &= ~ATTR_SIZE;
 413         }
 414
 415         /* Optimization: if the end result is no change, don't RPC */
 416         attr->ia_valid &= NFS_VALID_ATTRS;
 417         if ((attr->ia_valid & ~ATTR_FILE) == 0)
 418                 return 0;
 419
 420         /* Write all dirty data */
 421         if (S_ISREG(inode->i_mode))
 422                 nfs_wb_all(inode);
 423
 424         fattr = nfs_alloc_fattr();
 425         if (fattr == NULL)
 426                 goto out;
 427         /*
 428          * Return any delegations if we're going to change ACLs
 429          */
 430         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
 431                 nfs_inode_return_delegation(inode);
 432         error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
 433         if (error == 0)
 434                 nfs_refresh_inode(inode, fattr);
 435         nfs_free_fattr(fattr);
 436 out:
 437         return error;
 438 }
 439
 440 /**
 441  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
 442  * @inode: inode of the file used
 443  * @offset: file offset to start truncating
 444  *
 445  * This is a copy of the common vmtruncate, but with the locking
 446  * corrected to take into account the fact that NFS requires
 447  * inode->i_size to be updated under the inode->i_lock.
 448  */
 449 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
 450 {
 451         loff_t oldsize;
 452         int err;
 453
 454         err = inode_newsize_ok(inode, offset);
 455         if (err)
 456                 goto out;
 457
 458         spin_lock(&inode->i_lock);
 459         oldsize = inode->i_size;
 460         i_size_write(inode, offset);
 461         spin_unlock(&inode->i_lock);
 462
 463         truncate_pagecache(inode, oldsize, offset);
 464 out:
 465         return err;
 466 }
 467
 468 /**
 469  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
 470  * @inode: pointer to struct inode
 471  * @attr: pointer to struct iattr
 472  *
 473  * Note: we do this in the *proc.c in order to ensure that
 474  *       it works for things like exclusive creates too.
 475  */
 476 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
 477 {
 478         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
 479                 spin_lock(&inode->i_lock);
 480                 if ((attr->ia_valid & ATTR_MODE) != 0) {
 481                         int mode = attr->ia_mode & S_IALLUGO;
 482                         mode |= inode->i_mode & ~S_IALLUGO;
 483                         inode->i_mode = mode;
 484                 }
 485                 if ((attr->ia_valid & ATTR_UID) != 0)
 486                         inode->i_uid = attr->ia_uid;
 487                 if ((attr->ia_valid & ATTR_GID) != 0)
 488                         inode->i_gid = attr->ia_gid;
 489                 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
 490                 spin_unlock(&inode->i_lock);
 491         }
 492         if ((attr->ia_valid & ATTR_SIZE) != 0) {
 493                 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
 494                 nfs_vmtruncate(inode, attr->ia_size);
 495         }
 496 }
 497
 498 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 499 {
 500         struct inode *inode = dentry->d_inode;
 501         int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
 502         int err;
 503
 504         /* Flush out writes to the server in order to update c/mtime.  */
 505         if (S_ISREG(inode->i_mode)) {
 506                 err = filemap_write_and_wait(inode->i_mapping);
 507                 if (err)
 508                         goto out;
 509         }
 510
 511         /*
 512          * We may force a getattr if the user cares about atime.
 513          *
 514          * Note that we only have to check the vfsmount flags here:
 515          *  - NFS always sets S_NOATIME by so checking it would give a
 516          *    bogus result
 517          *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
 518          *    no point in checking those.
 519          */
 520         if ((mnt->mnt_flags & MNT_NOATIME) ||
 521             ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
 522                 need_atime = 0;
 523
 524         if (need_atime)
 525                 err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
 526         else
 527                 err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
 528         if (!err) {
 529                 generic_fillattr(inode, stat);
 530                 stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
 531         }
 532 out:
 533         return err;
 534 }
 535
 536 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
 537 {
 538         atomic_set(&l_ctx->count, 1);
 539         l_ctx->lockowner = current->files;
 540         l_ctx->pid = current->tgid;
 541         INIT_LIST_HEAD(&l_ctx->list);
 542 }
 543
 544 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
 545 {
 546         struct nfs_lock_context *pos;
 547
 548         list_for_each_entry(pos, &ctx->lock_context.list, list) {
 549                 if (pos->lockowner != current->files)
 550                         continue;
 551                 if (pos->pid != current->tgid)
 552                         continue;
 553                 atomic_inc(&pos->count);
 554                 return pos;
 555         }
 556         return NULL;
 557 }
 558
 559 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
 560 {
 561         struct nfs_lock_context *res, *new = NULL;
 562         struct inode *inode = ctx->path.dentry->d_inode;
 563
 564         spin_lock(&inode->i_lock);
 565         res = __nfs_find_lock_context(ctx);
 566         if (res == NULL) {
 567                 spin_unlock(&inode->i_lock);
 568                 new = kmalloc(sizeof(*new), GFP_KERNEL);
 569                 if (new == NULL)
 570                         return NULL;
 571                 nfs_init_lock_context(new);
 572                 spin_lock(&inode->i_lock);
 573                 res = __nfs_find_lock_context(ctx);
 574                 if (res == NULL) {
 575                         list_add_tail(&new->list, &ctx->lock_context.list);
 576                         new->open_context = ctx;
 577                         res = new;
 578                         new = NULL;
 579                 }
 580         }
 581         spin_unlock(&inode->i_lock);
 582         kfree(new);
 583         return res;
 584 }
 585
 586 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
 587 {
 588         struct nfs_open_context *ctx = l_ctx->open_context;
 589         struct inode *inode = ctx->path.dentry->d_inode;
 590
 591         if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
 592                 return;
 593         list_del(&l_ctx->list);
 594         spin_unlock(&inode->i_lock);
 595         kfree(l_ctx);
 596 }
 597
 598 /**
 599  * nfs_close_context - Common close_context() routine NFSv2/v3
 600  * @ctx: pointer to context
 601  * @is_sync: is this a synchronous close
 602  *
 603  * always ensure that the attributes are up to date if we're mounted
 604  * with close-to-open semantics
 605  */
 606 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
 607 {
 608         struct inode *inode;
 609         struct nfs_server *server;
 610
 611         if (!(ctx->mode & FMODE_WRITE))
 612                 return;
 613         if (!is_sync)
 614                 return;
 615         inode = ctx->path.dentry->d_inode;
 616         if (!list_empty(&NFS_I(inode)->open_files))
 617                 return;
 618         server = NFS_SERVER(inode);
 619         if (server->flags & NFS_MOUNT_NOCTO)
 620                 return;
 621         nfs_revalidate_inode(server, inode);
 622 }
 623
 624 struct nfs_open_context *alloc_nfs_open_context(struct path *path, struct rpc_cred *cred, fmode_t f_mode)
 625 {
 626         struct nfs_open_context *ctx;
 627
 628         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
 629         if (ctx != NULL) {
 630                 ctx->path = *path;
 631                 path_get(&ctx->path);
 632                 ctx->cred = get_rpccred(cred);
 633                 ctx->state = NULL;
 634                 ctx->mode = f_mode;
 635                 ctx->flags = 0;
 636                 ctx->error = 0;
 637                 ctx->dir_cookie = 0;
 638                 nfs_init_lock_context(&ctx->lock_context);
 639                 ctx->lock_context.open_context = ctx;
 640                 INIT_LIST_HEAD(&ctx->list);
 641         }
 642         return ctx;
 643 }
 644
 645 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
 646 {
 647         if (ctx != NULL)
 648                 atomic_inc(&ctx->lock_context.count);
 649         return ctx;
 650 }
 651
 652 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
 653 {
 654         struct inode *inode = ctx->path.dentry->d_inode;
 655
 656         if (!list_empty(&ctx->list)) {
 657                 if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
 658                         return;
 659                 list_del(&ctx->list);
 660                 spin_unlock(&inode->i_lock);
 661         } else if (!atomic_dec_and_test(&ctx->lock_context.count))
 662                 return;
 663         if (inode != NULL)
 664                 NFS_PROTO(inode)->close_context(ctx, is_sync);
 665         if (ctx->cred != NULL)
 666                 put_rpccred(ctx->cred);
 667         path_put(&ctx->path);
 668         kfree(ctx);
 669 }
 670
 671 void put_nfs_open_context(struct nfs_open_context *ctx)
 672 {
 673         __put_nfs_open_context(ctx, 0);
 674 }
 675
 676 /*
 677  * Ensure that mmap has a recent RPC credential for use when writing out
 678  * shared pages
 679  */
 680 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
 681 {
 682         struct inode *inode = filp->f_path.dentry->d_inode;
 683         struct nfs_inode *nfsi = NFS_I(inode);
 684
 685         filp->private_data = get_nfs_open_context(ctx);
 686         spin_lock(&inode->i_lock);
 687         list_add(&ctx->list, &nfsi->open_files);
 688         spin_unlock(&inode->i_lock);
 689 }
 690
 691 /*
 692  * Given an inode, search for an open context with the desired characteristics
 693  */
 694 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
 695 {
 696         struct nfs_inode *nfsi = NFS_I(inode);
 697         struct nfs_open_context *pos, *ctx = NULL;
 698
 699         spin_lock(&inode->i_lock);
 700         list_for_each_entry(pos, &nfsi->open_files, list) {
 701                 if (cred != NULL && pos->cred != cred)
 702                         continue;
 703                 if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
 704                         continue;
 705                 ctx = get_nfs_open_context(pos);
 706                 break;
 707         }
 708         spin_unlock(&inode->i_lock);
 709         return ctx;
 710 }
 711
 712 static void nfs_file_clear_open_context(struct file *filp)
 713 {
 714         struct inode *inode = filp->f_path.dentry->d_inode;
 715         struct nfs_open_context *ctx = nfs_file_open_context(filp);
 716
 717         if (ctx) {
 718                 filp->private_data = NULL;
 719                 spin_lock(&inode->i_lock);
 720                 list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
 721                 spin_unlock(&inode->i_lock);
 722                 __put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
 723         }
 724 }
 725
 726 /*
 727  * These allocate and release file read/write context information.
 728  */
 729 int nfs_open(struct inode *inode, struct file *filp)
 730 {
 731         struct nfs_open_context *ctx;
 732         struct rpc_cred *cred;
 733
 734         cred = rpc_lookup_cred();
 735         if (IS_ERR(cred))
 736                 return PTR_ERR(cred);
 737         ctx = alloc_nfs_open_context(&filp->f_path, cred, filp->f_mode);
 738         put_rpccred(cred);
 739         if (ctx == NULL)
 740                 return -ENOMEM;
 741         nfs_file_set_open_context(filp, ctx);
 742         put_nfs_open_context(ctx);
 743         nfs_fscache_set_inode_cookie(inode, filp);
 744         return 0;
 745 }
 746
 747 int nfs_release(struct inode *inode, struct file *filp)
 748 {
 749         nfs_file_clear_open_context(filp);
 750         return 0;
 751 }
 752
 753 /*
 754  * This function is called whenever some part of NFS notices that
 755  * the cached attributes have to be refreshed.
 756  */
 757 int
 758 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
 759 {
 760         int              status = -ESTALE;
 761         struct nfs_fattr *fattr = NULL;
 762         struct nfs_inode *nfsi = NFS_I(inode);
 763
 764         dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
 765                 inode->i_sb->s_id, (long long)NFS_FILEID(inode));
 766
 767         if (is_bad_inode(inode))
 768                 goto out;
 769         if (NFS_STALE(inode))
 770                 goto out;
 771
 772         status = -ENOMEM;
 773         fattr = nfs_alloc_fattr();
 774         if (fattr == NULL)
 775                 goto out;
 776
 777         nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
 778         status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
 779         if (status != 0) {
 780                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
 781                          inode->i_sb->s_id,
 782                          (long long)NFS_FILEID(inode), status);
 783                 if (status == -ESTALE) {
 784                         nfs_zap_caches(inode);
 785                         if (!S_ISDIR(inode->i_mode))
 786                                 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 787                 }
 788                 goto out;
 789         }
 790
 791         status = nfs_refresh_inode(inode, fattr);
 792         if (status) {
 793                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
 794                          inode->i_sb->s_id,
 795                          (long long)NFS_FILEID(inode), status);
 796                 goto out;
 797         }
 798
 799         if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
 800                 nfs_zap_acl_cache(inode);
 801
 802         dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
 803                 inode->i_sb->s_id,
 804                 (long long)NFS_FILEID(inode));
 805
 806  out:
 807         nfs_free_fattr(fattr);
 808         return status;
 809 }
 810
 811 int nfs_attribute_timeout(struct inode *inode)
 812 {
 813         struct nfs_inode *nfsi = NFS_I(inode);
 814
 815         return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
 816 }
 817
 818 static int nfs_attribute_cache_expired(struct inode *inode)
 819 {
 820         if (nfs_have_delegated_attributes(inode))
 821                 return 0;
 822         return nfs_attribute_timeout(inode);
 823 }
 824
 825 /**
 826  * nfs_revalidate_inode - Revalidate the inode attributes
 827  * @server - pointer to nfs_server struct
 828  * @inode - pointer to inode struct
 829  *
 830  * Updates inode attribute information by retrieving the data from the server.
 831  */
 832 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
 833 {
 834         if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
 835                         && !nfs_attribute_cache_expired(inode))
 836                 return NFS_STALE(inode) ? -ESTALE : 0;
 837         return __nfs_revalidate_inode(server, inode);
 838 }
 839
 840 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
 841 {
 842         struct nfs_inode *nfsi = NFS_I(inode);
 843
 844         if (mapping->nrpages != 0) {
 845                 int ret = invalidate_inode_pages2(mapping);
 846                 if (ret < 0)
 847                         return ret;
 848         }
 849         spin_lock(&inode->i_lock);
 850         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
 851         if (S_ISDIR(inode->i_mode))
 852                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
 853         spin_unlock(&inode->i_lock);
 854         nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
 855         nfs_fscache_reset_inode_cookie(inode);
 856         dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
 857                         inode->i_sb->s_id, (long long)NFS_FILEID(inode));
 858         return 0;
 859 }
 860
 861 /**
 862  * nfs_revalidate_mapping - Revalidate the pagecache
 863  * @inode - pointer to host inode
 864  * @mapping - pointer to mapping
 865  */
 866 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
 867 {
 868         struct nfs_inode *nfsi = NFS_I(inode);
 869         int ret = 0;
 870
 871         if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
 872                         || nfs_attribute_cache_expired(inode)
 873                         || NFS_STALE(inode)) {
 874                 ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
 875                 if (ret < 0)
 876                         goto out;
 877         }
 878         if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
 879                 ret = nfs_invalidate_mapping(inode, mapping);
 880 out:
 881         return ret;
 882 }
 883
 884 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 885 {
 886         struct nfs_inode *nfsi = NFS_I(inode);
 887         unsigned long ret = 0;
 888
 889         if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
 890                         && (fattr->valid & NFS_ATTR_FATTR_CHANGE)
 891                         && nfsi->change_attr == fattr->pre_change_attr) {
 892                 nfsi->change_attr = fattr->change_attr;
 893                 if (S_ISDIR(inode->i_mode))
 894                         nfsi->cache_validity |= NFS_INO_INVALID_DATA;
 895                 ret |= NFS_INO_INVALID_ATTR;
 896         }
 897         /* If we have atomic WCC data, we may update some attributes */
 898         if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
 899                         && (fattr->valid & NFS_ATTR_FATTR_CTIME)
 900                         && timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
 901                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
 902                 ret |= NFS_INO_INVALID_ATTR;
 903         }
 904
 905         if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
 906                         && (fattr->valid & NFS_ATTR_FATTR_MTIME)
 907                         && timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
 908                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
 909                 if (S_ISDIR(inode->i_mode))
 910                         nfsi->cache_validity |= NFS_INO_INVALID_DATA;
 911                 ret |= NFS_INO_INVALID_ATTR;
 912         }
 913         if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
 914                         && (fattr->valid & NFS_ATTR_FATTR_SIZE)
 915                         && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
 916                         && nfsi->npages == 0) {
 917                 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
 918                 ret |= NFS_INO_INVALID_ATTR;
 919         }
 920         return ret;
 921 }
 922
 923 /**
 924  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
 925  * @inode - pointer to inode
 926  * @fattr - updated attributes
 927  *
 928  * Verifies the attribute cache. If we have just changed the attributes,
 929  * so that fattr carries weak cache consistency data, then it may
 930  * also update the ctime/mtime/change_attribute.
 931  */
 932 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
 933 {
 934         struct nfs_inode *nfsi = NFS_I(inode);
 935         loff_t cur_size, new_isize;
 936         unsigned long invalid = 0;
 937
 938
 939         /* Has the inode gone and changed behind our back? */
 940         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
 941                 return -EIO;
 942         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
 943                 return -EIO;
 944
 945         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
 946                         nfsi->change_attr != fattr->change_attr)
 947                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
 948
 949         /* Verify a few of the more important attributes */
 950         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
 951                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
 952
 953         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
 954                 cur_size = i_size_read(inode);
 955                 new_isize = nfs_size_to_loff_t(fattr->size);
 956                 if (cur_size != new_isize && nfsi->npages == 0)
 957                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
 958         }
 959
 960         /* Have any file permissions changed? */
 961         if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
 962                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
 963         if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && inode->i_uid != fattr->uid)
 964                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
 965         if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && inode->i_gid != fattr->gid)
 966                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
 967
 968         /* Has the link count changed? */
 969         if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
 970                 invalid |= NFS_INO_INVALID_ATTR;
 971
 972         if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
 973                 invalid |= NFS_INO_INVALID_ATIME;
 974
 975         if (invalid != 0)
 976                 nfsi->cache_validity |= invalid;
 977
 978         nfsi->read_cache_jiffies = fattr->time_start;
 979         return 0;
 980 }
 981
 982 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
 983 {
 984         if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
 985                 return 0;
 986         return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
 987 }
 988
 989 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
 990 {
 991         if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
 992                 return 0;
 993         return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
 994 }
 995
 996 static atomic_long_t nfs_attr_generation_counter;
 997
 998 static unsigned long nfs_read_attr_generation_counter(void)
 999 {
1000         return atomic_long_read(&nfs_attr_generation_counter);
1001 }
1002
1003 unsigned long nfs_inc_attr_generation_counter(void)
1004 {
1005         return atomic_long_inc_return(&nfs_attr_generation_counter);
1006 }
1007
1008 void nfs_fattr_init(struct nfs_fattr *fattr)
1009 {
1010         fattr->valid = 0;
1011         fattr->time_start = jiffies;
1012         fattr->gencount = nfs_inc_attr_generation_counter();
1013 }
1014
1015 struct nfs_fattr *nfs_alloc_fattr(void)
1016 {
1017         struct nfs_fattr *fattr;
1018
1019         fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1020         if (fattr != NULL)
1021                 nfs_fattr_init(fattr);
1022         return fattr;
1023 }
1024
1025 struct nfs_fh *nfs_alloc_fhandle(void)
1026 {
1027         struct nfs_fh *fh;
1028
1029         fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1030         if (fh != NULL)
1031                 fh->size = 0;
1032         return fh;
1033 }
1034
1035 /**
1036  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1037  * @inode - pointer to inode
1038  * @fattr - attributes
1039  *
1040  * Attempt to divine whether or not an RPC call reply carrying stale
1041  * attributes got scheduled after another call carrying updated ones.
1042  *
1043  * To do so, the function first assumes that a more recent ctime means
1044  * that the attributes in fattr are newer, however it also attempt to
1045  * catch the case where ctime either didn't change, or went backwards
1046  * (if someone reset the clock on the server) by looking at whether
1047  * or not this RPC call was started after the inode was last updated.
1048  * Note also the check for wraparound of 'attr_gencount'
1049  *
1050  * The function returns 'true' if it thinks the attributes in 'fattr' are
1051  * more recent than the ones cached in the inode.
1052  *
1053  */
1054 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1055 {
1056         const struct nfs_inode *nfsi = NFS_I(inode);
1057
1058         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1059                 nfs_ctime_need_update(inode, fattr) ||
1060                 nfs_size_need_update(inode, fattr) ||
1061                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1062 }
1063
1064 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1065 {
1066         if (nfs_inode_attrs_need_update(inode, fattr))
1067                 return nfs_update_inode(inode, fattr);
1068         return nfs_check_inode_attributes(inode, fattr);
1069 }
1070
1071 /**
1072  * nfs_refresh_inode - try to update the inode attribute cache
1073  * @inode - pointer to inode
1074  * @fattr - updated attributes
1075  *
1076  * Check that an RPC call that returned attributes has not overlapped with
1077  * other recent updates of the inode metadata, then decide whether it is
1078  * safe to do a full update of the inode attributes, or whether just to
1079  * call nfs_check_inode_attributes.
1080  */
1081 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1082 {
1083         int status;
1084
1085         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1086                 return 0;
1087         spin_lock(&inode->i_lock);
1088         status = nfs_refresh_inode_locked(inode, fattr);
1089         spin_unlock(&inode->i_lock);
1090
1091         return status;
1092 }
1093
1094 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1095 {
1096         struct nfs_inode *nfsi = NFS_I(inode);
1097
1098         nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1099         if (S_ISDIR(inode->i_mode))
1100                 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1101         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1102                 return 0;
1103         return nfs_refresh_inode_locked(inode, fattr);
1104 }
1105
1106 /**
1107  * nfs_post_op_update_inode - try to update the inode attribute cache
1108  * @inode - pointer to inode
1109  * @fattr - updated attributes
1110  *
1111  * After an operation that has changed the inode metadata, mark the
1112  * attribute cache as being invalid, then try to update it.
1113  *
1114  * NB: if the server didn't return any post op attributes, this
1115  * function will force the retrieval of attributes before the next
1116  * NFS request.  Thus it should be used only for operations that
1117  * are expected to change one or more attributes, to avoid
1118  * unnecessary NFS requests and trips through nfs_update_inode().
1119  */
1120 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1121 {
1122         int status;
1123
1124         spin_lock(&inode->i_lock);
1125         status = nfs_post_op_update_inode_locked(inode, fattr);
1126         spin_unlock(&inode->i_lock);
1127         return status;
1128 }
1129
1130 /**
1131  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1132  * @inode - pointer to inode
1133  * @fattr - updated attributes
1134  *
1135  * After an operation that has changed the inode metadata, mark the
1136  * attribute cache as being invalid, then try to update it. Fake up
1137  * weak cache consistency data, if none exist.
1138  *
1139  * This function is mainly designed to be used by the ->write_done() functions.
1140  */
1141 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1142 {
1143         int status;
1144
1145         spin_lock(&inode->i_lock);
1146         /* Don't do a WCC update if these attributes are already stale */
1147         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1148                         !nfs_inode_attrs_need_update(inode, fattr)) {
1149                 fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1150                                 | NFS_ATTR_FATTR_PRESIZE
1151                                 | NFS_ATTR_FATTR_PREMTIME
1152                                 | NFS_ATTR_FATTR_PRECTIME);
1153                 goto out_noforce;
1154         }
1155         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1156                         (fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1157                 fattr->pre_change_attr = NFS_I(inode)->change_attr;
1158                 fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1159         }
1160         if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1161                         (fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1162                 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1163                 fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1164         }
1165         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1166                         (fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1167                 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1168                 fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1169         }
1170         if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1171                         (fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1172                 fattr->pre_size = i_size_read(inode);
1173                 fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1174         }
1175 out_noforce:
1176         status = nfs_post_op_update_inode_locked(inode, fattr);
1177         spin_unlock(&inode->i_lock);
1178         return status;
1179 }
1180
1181 /*
1182  * Many nfs protocol calls return the new file attributes after
1183  * an operation.  Here we update the inode to reflect the state
1184  * of the server's inode.
1185  *
1186  * This is a bit tricky because we have to make sure all dirty pages
1187  * have been sent off to the server before calling invalidate_inode_pages.
1188  * To make sure no other process adds more write requests while we try
1189  * our best to flush them, we make them sleep during the attribute refresh.
1190  *
1191  * A very similar scenario holds for the dir cache.
1192  */
1193 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1194 {
1195         struct nfs_server *server;
1196         struct nfs_inode *nfsi = NFS_I(inode);
1197         loff_t cur_isize, new_isize;
1198         unsigned long invalid = 0;
1199         unsigned long now = jiffies;
1200         unsigned long save_cache_validity;
1201
1202         dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
1203                         __func__, inode->i_sb->s_id, inode->i_ino,
1204                         atomic_read(&inode->i_count), fattr->valid);
1205
1206         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1207                 goto out_fileid;
1208
1209         /*
1210          * Make sure the inode's type hasn't changed.
1211          */
1212         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1213                 goto out_changed;
1214
1215         server = NFS_SERVER(inode);
1216         /* Update the fsid? */
1217         if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1218                         !nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1219                         !IS_AUTOMOUNT(inode))
1220                 server->fsid = fattr->fsid;
1221
1222         /*
1223          * Update the read time so we don't revalidate too often.
1224          */
1225         nfsi->read_cache_jiffies = fattr->time_start;
1226
1227         save_cache_validity = nfsi->cache_validity;
1228         nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1229                         | NFS_INO_INVALID_ATIME
1230                         | NFS_INO_REVAL_FORCED
1231                         | NFS_INO_REVAL_PAGECACHE);
1232
1233         /* Do atomic weak cache consistency updates */
1234         invalid |= nfs_wcc_update_inode(inode, fattr);
1235
1236         /* More cache consistency checks */
1237         if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1238                 if (nfsi->change_attr != fattr->change_attr) {
1239                         dprintk("NFS: change_attr change on server for file %s/%ld\n",
1240                                         inode->i_sb->s_id, inode->i_ino);
1241                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1242                         if (S_ISDIR(inode->i_mode))
1243                                 nfs_force_lookup_revalidate(inode);
1244                         nfsi->change_attr = fattr->change_attr;
1245                 }
1246         } else if (server->caps & NFS_CAP_CHANGE_ATTR)
1247                 invalid |= save_cache_validity;
1248
1249         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1250                 /* NFSv2/v3: Check if the mtime agrees */
1251                 if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1252                         dprintk("NFS: mtime change on server for file %s/%ld\n",
1253                                         inode->i_sb->s_id, inode->i_ino);
1254                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1255                         if (S_ISDIR(inode->i_mode))
1256                                 nfs_force_lookup_revalidate(inode);
1257                         memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1258                 }
1259         } else if (server->caps & NFS_CAP_MTIME)
1260                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1261                                 | NFS_INO_INVALID_DATA
1262                                 | NFS_INO_REVAL_PAGECACHE
1263                                 | NFS_INO_REVAL_FORCED);
1264
1265         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1266                 /* If ctime has changed we should definitely clear access+acl caches */
1267                 if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) {
1268                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1269                         /* and probably clear data for a directory too as utimes can cause
1270                          * havoc with our cache.
1271                          */
1272                         if (S_ISDIR(inode->i_mode)) {
1273                                 invalid |= NFS_INO_INVALID_DATA;
1274                                 nfs_force_lookup_revalidate(inode);
1275                         }
1276                         memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1277                 }
1278         } else if (server->caps & NFS_CAP_CTIME)
1279                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1280                                 | NFS_INO_INVALID_ACCESS
1281                                 | NFS_INO_INVALID_ACL
1282                                 | NFS_INO_REVAL_FORCED);
1283
1284         /* Check if our cached file size is stale */
1285         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1286                 new_isize = nfs_size_to_loff_t(fattr->size);
1287                 cur_isize = i_size_read(inode);
1288                 if (new_isize != cur_isize) {
1289                         /* Do we perhaps have any outstanding writes, or has
1290                          * the file grown beyond our last write? */
1291                         if (nfsi->npages == 0 || new_isize > cur_isize) {
1292                                 i_size_write(inode, new_isize);
1293                                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1294                         }
1295                         dprintk("NFS: isize change on server for file %s/%ld\n",
1296                                         inode->i_sb->s_id, inode->i_ino);
1297                 }
1298         } else
1299                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1300                                 | NFS_INO_REVAL_PAGECACHE
1301                                 | NFS_INO_REVAL_FORCED);
1302
1303
1304         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1305                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1306         else if (server->caps & NFS_CAP_ATIME)
1307                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1308                                 | NFS_INO_REVAL_FORCED);
1309
1310         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1311                 if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1312                         umode_t newmode = inode->i_mode & S_IFMT;
1313                         newmode |= fattr->mode & S_IALLUGO;
1314                         inode->i_mode = newmode;
1315                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1316                 }
1317         } else if (server->caps & NFS_CAP_MODE)
1318                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1319                                 | NFS_INO_INVALID_ACCESS
1320                                 | NFS_INO_INVALID_ACL
1321                                 | NFS_INO_REVAL_FORCED);
1322
1323         if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1324                 if (inode->i_uid != fattr->uid) {
1325                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1326                         inode->i_uid = fattr->uid;
1327                 }
1328         } else if (server->caps & NFS_CAP_OWNER)
1329                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1330                                 | NFS_INO_INVALID_ACCESS
1331                                 | NFS_INO_INVALID_ACL
1332                                 | NFS_INO_REVAL_FORCED);
1333
1334         if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1335                 if (inode->i_gid != fattr->gid) {
1336                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1337                         inode->i_gid = fattr->gid;
1338                 }
1339         } else if (server->caps & NFS_CAP_OWNER_GROUP)
1340                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1341                                 | NFS_INO_INVALID_ACCESS
1342                                 | NFS_INO_INVALID_ACL
1343                                 | NFS_INO_REVAL_FORCED);
1344
1345         if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1346                 if (inode->i_nlink != fattr->nlink) {
1347                         invalid |= NFS_INO_INVALID_ATTR;
1348                         if (S_ISDIR(inode->i_mode))
1349                                 invalid |= NFS_INO_INVALID_DATA;
1350                         inode->i_nlink = fattr->nlink;
1351                 }
1352         } else if (server->caps & NFS_CAP_NLINK)
1353                 invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1354                                 | NFS_INO_REVAL_FORCED);
1355
1356         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1357                 /*
1358                  * report the blocks in 512byte units
1359                  */
1360                 inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1361         }
1362         if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1363                 inode->i_blocks = fattr->du.nfs2.blocks;
1364
1365         /* Update attrtimeo value if we're out of the unstable period */
1366         if (invalid & NFS_INO_INVALID_ATTR) {
1367                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1368                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1369                 nfsi->attrtimeo_timestamp = now;
1370                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1371         } else {
1372                 if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1373                         if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1374                                 nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1375                         nfsi->attrtimeo_timestamp = now;
1376                 }
1377         }
1378         invalid &= ~NFS_INO_INVALID_ATTR;
1379         /* Don't invalidate the data if we were to blame */
1380         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1381                                 || S_ISLNK(inode->i_mode)))
1382                 invalid &= ~NFS_INO_INVALID_DATA;
1383         if (!nfs_have_delegation(inode, FMODE_READ) ||
1384                         (save_cache_validity & NFS_INO_REVAL_FORCED))
1385                 nfsi->cache_validity |= invalid;
1386
1387         return 0;
1388  out_changed:
1389         /*
1390          * Big trouble! The inode has become a different object.
1391          */
1392         printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
1393                         __func__, inode->i_ino, inode->i_mode, fattr->mode);
1394  out_err:
1395         /*
1396          * No need to worry about unhashing the dentry, as the
1397          * lookup validation will know that the inode is bad.
1398          * (But we fall through to invalidate the caches.)
1399          */
1400         nfs_invalidate_inode(inode);
1401         return -ESTALE;
1402
1403  out_fileid:
1404         printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1405                 "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1406                 NFS_SERVER(inode)->nfs_client->cl_hostname, inode->i_sb->s_id,
1407                 (long long)nfsi->fileid, (long long)fattr->fileid);
1408         goto out_err;
1409 }
1410
1411
1412 #ifdef CONFIG_NFS_V4
1413
1414 /*
1415  * Clean out any remaining NFSv4 state that might be left over due
1416  * to open() calls that passed nfs_atomic_lookup, but failed to call
1417  * nfs_open().
1418  */
1419 void nfs4_evict_inode(struct inode *inode)
1420 {
1421         pnfs_destroy_layout(NFS_I(inode));
1422         truncate_inode_pages(&inode->i_data, 0);
1423         end_writeback(inode);
1424         /* If we are holding a delegation, return it! */
1425         nfs_inode_return_delegation_noreclaim(inode);
1426         /* First call standard NFS clear_inode() code */
1427         nfs_clear_inode(inode);
1428 }
1429 #endif
1430
1431 struct inode *nfs_alloc_inode(struct super_block *sb)
1432 {
1433         struct nfs_inode *nfsi;
1434         nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1435         if (!nfsi)
1436                 return NULL;
1437         nfsi->flags = 0UL;
1438         nfsi->cache_validity = 0UL;
1439 #ifdef CONFIG_NFS_V3_ACL
1440         nfsi->acl_access = ERR_PTR(-EAGAIN);
1441         nfsi->acl_default = ERR_PTR(-EAGAIN);
1442 #endif
1443 #ifdef CONFIG_NFS_V4
1444         nfsi->nfs4_acl = NULL;
1445 #endif /* CONFIG_NFS_V4 */
1446         return &nfsi->vfs_inode;
1447 }
1448
1449 static void nfs_i_callback(struct rcu_head *head)
1450 {
1451         struct inode *inode = container_of(head, struct inode, i_rcu);
1452         INIT_LIST_HEAD(&inode->i_dentry);
1453         kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1454 }
1455
1456 void nfs_destroy_inode(struct inode *inode)
1457 {
1458         call_rcu(&inode->i_rcu, nfs_i_callback);
1459 }
1460
1461 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1462 {
1463 #ifdef CONFIG_NFS_V4
1464         INIT_LIST_HEAD(&nfsi->open_states);
1465         nfsi->delegation = NULL;
1466         nfsi->delegation_state = 0;
1467         init_rwsem(&nfsi->rwsem);
1468         nfsi->layout = NULL;
1469 #endif
1470 }
1471
1472 static void init_once(void *foo)
1473 {
1474         struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1475
1476         inode_init_once(&nfsi->vfs_inode);
1477         INIT_LIST_HEAD(&nfsi->open_files);
1478         INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1479         INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1480         INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
1481         nfsi->npages = 0;
1482         nfsi->ncommit = 0;
1483         atomic_set(&nfsi->silly_count, 1);
1484         INIT_HLIST_HEAD(&nfsi->silly_list);
1485         init_waitqueue_head(&nfsi->waitqueue);
1486         nfs4_init_once(nfsi);
1487 }
1488
1489 static int __init nfs_init_inodecache(void)
1490 {
1491         nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1492                                              sizeof(struct nfs_inode),
1493                                              0, (SLAB_RECLAIM_ACCOUNT|
1494                                                 SLAB_MEM_SPREAD),
1495                                              init_once);
1496         if (nfs_inode_cachep == NULL)
1497                 return -ENOMEM;
1498
1499         return 0;
1500 }
1501
1502 static void nfs_destroy_inodecache(void)
1503 {
1504         kmem_cache_destroy(nfs_inode_cachep);
1505 }
1506
1507 struct workqueue_struct *nfsiod_workqueue;
1508
1509 /*
1510  * start up the nfsiod workqueue
1511  */
1512 static int nfsiod_start(void)
1513 {
1514         struct workqueue_struct *wq;
1515         dprintk("RPC:       creating workqueue nfsiod\n");
1516         wq = alloc_workqueue("nfsiod", WQ_RESCUER, 0);
1517         if (wq == NULL)
1518                 return -ENOMEM;
1519         nfsiod_workqueue = wq;
1520         return 0;
1521 }
1522
1523 /*
1524  * Destroy the nfsiod workqueue
1525  */
1526 static void nfsiod_stop(void)
1527 {
1528         struct workqueue_struct *wq;
1529
1530         wq = nfsiod_workqueue;
1531         if (wq == NULL)
1532                 return;
1533         nfsiod_workqueue = NULL;
1534         destroy_workqueue(wq);
1535 }
1536
1537 /*
1538  * Initialize NFS
1539  */
1540 static int __init init_nfs_fs(void)
1541 {
1542         int err;
1543
1544         err = nfs_idmap_init();
1545         if (err < 0)
1546                 goto out9;
1547
1548         err = nfs_dns_resolver_init();
1549         if (err < 0)
1550                 goto out8;
1551
1552         err = nfs_fscache_register();
1553         if (err < 0)
1554                 goto out7;
1555
1556         err = nfsiod_start();
1557         if (err)
1558                 goto out6;
1559
1560         err = nfs_fs_proc_init();
1561         if (err)
1562                 goto out5;
1563
1564         err = nfs_init_nfspagecache();
1565         if (err)
1566                 goto out4;
1567
1568         err = nfs_init_inodecache();
1569         if (err)
1570                 goto out3;
1571
1572         err = nfs_init_readpagecache();
1573         if (err)
1574                 goto out2;
1575
1576         err = nfs_init_writepagecache();
1577         if (err)
1578                 goto out1;
1579
1580         err = nfs_init_directcache();
1581         if (err)
1582                 goto out0;
1583
1584 #ifdef CONFIG_PROC_FS
1585         rpc_proc_register(&nfs_rpcstat);
1586 #endif
1587         if ((err = register_nfs_fs()) != 0)
1588                 goto out;
1589         return 0;
1590 out:
1591 #ifdef CONFIG_PROC_FS
1592         rpc_proc_unregister("nfs");
1593 #endif
1594         nfs_destroy_directcache();
1595 out0:
1596         nfs_destroy_writepagecache();
1597 out1:
1598         nfs_destroy_readpagecache();
1599 out2:
1600         nfs_destroy_inodecache();
1601 out3:
1602         nfs_destroy_nfspagecache();
1603 out4:
1604         nfs_fs_proc_exit();
1605 out5:
1606         nfsiod_stop();
1607 out6:
1608         nfs_fscache_unregister();
1609 out7:
1610         nfs_dns_resolver_destroy();
1611 out8:
1612         nfs_idmap_quit();
1613 out9:
1614         return err;
1615 }
1616
1617 static void __exit exit_nfs_fs(void)
1618 {
1619         nfs_destroy_directcache();
1620         nfs_destroy_writepagecache();
1621         nfs_destroy_readpagecache();
1622         nfs_destroy_inodecache();
1623         nfs_destroy_nfspagecache();
1624         nfs_fscache_unregister();
1625         nfs_dns_resolver_destroy();
1626         nfs_idmap_quit();
1627 #ifdef CONFIG_PROC_FS
1628         rpc_proc_unregister("nfs");
1629 #endif
1630         nfs_cleanup_cb_ident_idr();
1631         unregister_nfs_fs();
1632         nfs_fs_proc_exit();
1633         nfsiod_stop();
1634 }
1635
1636 /* Not quite true; I just maintain it */
1637 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1638 MODULE_LICENSE("GPL");
1639 module_param(enable_ino64, bool, 0644);
1640
1641 module_init(init_nfs_fs)
1642 module_exit(exit_nfs_fs)