Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/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/vfs.h>
 36 #include <linux/inet.h>
 37 #include <linux/nfs_xdr.h>
 38 #include <linux/slab.h>
 39 #include <linux/compat.h>
 40 #include <linux/freezer.h>
 41 
 42 #include <linux/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 "pnfs.h"
 51 #include "nfs.h"
 52 #include "netns.h"
 53 
 54 #include "nfstrace.h"
 55 
 56 #define NFSDBG_FACILITY         NFSDBG_VFS
 57 
 58 #define NFS_64_BIT_INODE_NUMBERS_ENABLED        1
 59 
 60 /* Default is to see 64-bit inode numbers */
 61 static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
 62 
 63 static void nfs_invalidate_inode(struct inode *);
 64 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
 65 
 66 static struct kmem_cache * nfs_inode_cachep;
 67 
 68 static inline unsigned long
 69 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
 70 {
 71         return nfs_fileid_to_ino_t(fattr->fileid);
 72 }
 73 
 74 static int nfs_wait_killable(int mode)
 75 {
 76         freezable_schedule_unsafe();
 77         if (signal_pending_state(mode, current))
 78                 return -ERESTARTSYS;
 79         return 0;
 80 }
 81 
 82 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
 83 {
 84         return nfs_wait_killable(mode);
 85 }
 86 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
 87 
 88 int nfs_wait_atomic_killable(atomic_t *p)
 89 {
 90         return nfs_wait_killable(TASK_KILLABLE);
 91 }
 92 
 93 /**
 94  * nfs_compat_user_ino64 - returns the user-visible inode number
 95  * @fileid: 64-bit fileid
 96  *
 97  * This function returns a 32-bit inode number if the boot parameter
 98  * nfs.enable_ino64 is zero.
 99  */
100 u64 nfs_compat_user_ino64(u64 fileid)
101 {
102 #ifdef CONFIG_COMPAT
103         compat_ulong_t ino;
104 #else   
105         unsigned long ino;
106 #endif
107 
108         if (enable_ino64)
109                 return fileid;
110         ino = fileid;
111         if (sizeof(ino) < sizeof(fileid))
112                 ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
113         return ino;
114 }
115 
116 int nfs_drop_inode(struct inode *inode)
117 {
118         return NFS_STALE(inode) || generic_drop_inode(inode);
119 }
120 EXPORT_SYMBOL_GPL(nfs_drop_inode);
121 
122 void nfs_clear_inode(struct inode *inode)
123 {
124         /*
125          * The following should never happen...
126          */
127         WARN_ON_ONCE(nfs_have_writebacks(inode));
128         WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
129         nfs_zap_acl_cache(inode);
130         nfs_access_zap_cache(inode);
131         nfs_fscache_clear_inode(inode);
132 }
133 EXPORT_SYMBOL_GPL(nfs_clear_inode);
134 
135 void nfs_evict_inode(struct inode *inode)
136 {
137         truncate_inode_pages_final(&inode->i_data);
138         clear_inode(inode);
139         nfs_clear_inode(inode);
140 }
141 
142 int nfs_sync_inode(struct inode *inode)
143 {
144         inode_dio_wait(inode);
145         return nfs_wb_all(inode);
146 }
147 EXPORT_SYMBOL_GPL(nfs_sync_inode);
148 
149 /**
150  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
151  */
152 int nfs_sync_mapping(struct address_space *mapping)
153 {
154         int ret = 0;
155 
156         if (mapping->nrpages != 0) {
157                 unmap_mapping_range(mapping, 0, 0, 0);
158                 ret = nfs_wb_all(mapping->host);
159         }
160         return ret;
161 }
162 
163 static int nfs_attribute_timeout(struct inode *inode)
164 {
165         struct nfs_inode *nfsi = NFS_I(inode);
166 
167         return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
168 }
169 
170 static bool nfs_check_cache_invalid_delegated(struct inode *inode, unsigned long flags)
171 {
172         unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
173 
174         /* Special case for the pagecache or access cache */
175         if (flags == NFS_INO_REVAL_PAGECACHE &&
176             !(cache_validity & NFS_INO_REVAL_FORCED))
177                 return false;
178         return (cache_validity & flags) != 0;
179 }
180 
181 static bool nfs_check_cache_invalid_not_delegated(struct inode *inode, unsigned long flags)
182 {
183         unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
184 
185         if ((cache_validity & flags) != 0)
186                 return true;
187         if (nfs_attribute_timeout(inode))
188                 return true;
189         return false;
190 }
191 
192 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
193 {
194         if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
195                 return nfs_check_cache_invalid_delegated(inode, flags);
196 
197         return nfs_check_cache_invalid_not_delegated(inode, flags);
198 }
199 
200 static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
201 {
202         struct nfs_inode *nfsi = NFS_I(inode);
203 
204         if (inode->i_mapping->nrpages == 0)
205                 flags &= ~NFS_INO_INVALID_DATA;
206         nfsi->cache_validity |= flags;
207         if (flags & NFS_INO_INVALID_DATA)
208                 nfs_fscache_invalidate(inode);
209 }
210 
211 /*
212  * Invalidate the local caches
213  */
214 static void nfs_zap_caches_locked(struct inode *inode)
215 {
216         struct nfs_inode *nfsi = NFS_I(inode);
217         int mode = inode->i_mode;
218 
219         nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
220 
221         nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
222         nfsi->attrtimeo_timestamp = jiffies;
223 
224         memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
225         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
226                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
227                                         | NFS_INO_INVALID_DATA
228                                         | NFS_INO_INVALID_ACCESS
229                                         | NFS_INO_INVALID_ACL
230                                         | NFS_INO_REVAL_PAGECACHE);
231         } else
232                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
233                                         | NFS_INO_INVALID_ACCESS
234                                         | NFS_INO_INVALID_ACL
235                                         | NFS_INO_REVAL_PAGECACHE);
236         nfs_zap_label_cache_locked(nfsi);
237 }
238 
239 void nfs_zap_caches(struct inode *inode)
240 {
241         spin_lock(&inode->i_lock);
242         nfs_zap_caches_locked(inode);
243         spin_unlock(&inode->i_lock);
244 }
245 
246 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
247 {
248         if (mapping->nrpages != 0) {
249                 spin_lock(&inode->i_lock);
250                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
251                 spin_unlock(&inode->i_lock);
252         }
253 }
254 
255 void nfs_zap_acl_cache(struct inode *inode)
256 {
257         void (*clear_acl_cache)(struct inode *);
258 
259         clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
260         if (clear_acl_cache != NULL)
261                 clear_acl_cache(inode);
262         spin_lock(&inode->i_lock);
263         NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
264         spin_unlock(&inode->i_lock);
265 }
266 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
267 
268 void nfs_invalidate_atime(struct inode *inode)
269 {
270         spin_lock(&inode->i_lock);
271         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
272         spin_unlock(&inode->i_lock);
273 }
274 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
275 
276 /*
277  * Invalidate, but do not unhash, the inode.
278  * NB: must be called with inode->i_lock held!
279  */
280 static void nfs_invalidate_inode(struct inode *inode)
281 {
282         set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
283         nfs_zap_caches_locked(inode);
284 }
285 
286 struct nfs_find_desc {
287         struct nfs_fh           *fh;
288         struct nfs_fattr        *fattr;
289 };
290 
291 /*
292  * In NFSv3 we can have 64bit inode numbers. In order to support
293  * this, and re-exported directories (also seen in NFSv2)
294  * we are forced to allow 2 different inodes to have the same
295  * i_ino.
296  */
297 static int
298 nfs_find_actor(struct inode *inode, void *opaque)
299 {
300         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
301         struct nfs_fh           *fh = desc->fh;
302         struct nfs_fattr        *fattr = desc->fattr;
303 
304         if (NFS_FILEID(inode) != fattr->fileid)
305                 return 0;
306         if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
307                 return 0;
308         if (nfs_compare_fh(NFS_FH(inode), fh))
309                 return 0;
310         if (is_bad_inode(inode) || NFS_STALE(inode))
311                 return 0;
312         return 1;
313 }
314 
315 static int
316 nfs_init_locked(struct inode *inode, void *opaque)
317 {
318         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
319         struct nfs_fattr        *fattr = desc->fattr;
320 
321         set_nfs_fileid(inode, fattr->fileid);
322         inode->i_mode = fattr->mode;
323         nfs_copy_fh(NFS_FH(inode), desc->fh);
324         return 0;
325 }
326 
327 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
328 static void nfs_clear_label_invalid(struct inode *inode)
329 {
330         spin_lock(&inode->i_lock);
331         NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
332         spin_unlock(&inode->i_lock);
333 }
334 
335 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
336                                         struct nfs4_label *label)
337 {
338         int error;
339 
340         if (label == NULL)
341                 return;
342 
343         if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
344                 error = security_inode_notifysecctx(inode, label->label,
345                                 label->len);
346                 if (error)
347                         printk(KERN_ERR "%s() %s %d "
348                                         "security_inode_notifysecctx() %d\n",
349                                         __func__,
350                                         (char *)label->label,
351                                         label->len, error);
352                 nfs_clear_label_invalid(inode);
353         }
354 }
355 
356 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
357 {
358         struct nfs4_label *label = NULL;
359         int minor_version = server->nfs_client->cl_minorversion;
360 
361         if (minor_version < 2)
362                 return label;
363 
364         if (!(server->caps & NFS_CAP_SECURITY_LABEL))
365                 return label;
366 
367         label = kzalloc(sizeof(struct nfs4_label), flags);
368         if (label == NULL)
369                 return ERR_PTR(-ENOMEM);
370 
371         label->label = kzalloc(NFS4_MAXLABELLEN, flags);
372         if (label->label == NULL) {
373                 kfree(label);
374                 return ERR_PTR(-ENOMEM);
375         }
376         label->len = NFS4_MAXLABELLEN;
377 
378         return label;
379 }
380 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
381 #else
382 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
383                                         struct nfs4_label *label)
384 {
385 }
386 #endif
387 EXPORT_SYMBOL_GPL(nfs_setsecurity);
388 
389 /*
390  * This is our front-end to iget that looks up inodes by file handle
391  * instead of inode number.
392  */
393 struct inode *
394 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
395 {
396         struct nfs_find_desc desc = {
397                 .fh     = fh,
398                 .fattr  = fattr
399         };
400         struct inode *inode = ERR_PTR(-ENOENT);
401         unsigned long hash;
402 
403         nfs_attr_check_mountpoint(sb, fattr);
404 
405         if (nfs_attr_use_mounted_on_fileid(fattr))
406                 fattr->fileid = fattr->mounted_on_fileid;
407         else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
408                 goto out_no_inode;
409         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
410                 goto out_no_inode;
411 
412         hash = nfs_fattr_to_ino_t(fattr);
413 
414         inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
415         if (inode == NULL) {
416                 inode = ERR_PTR(-ENOMEM);
417                 goto out_no_inode;
418         }
419 
420         if (inode->i_state & I_NEW) {
421                 struct nfs_inode *nfsi = NFS_I(inode);
422                 unsigned long now = jiffies;
423 
424                 /* We set i_ino for the few things that still rely on it,
425                  * such as stat(2) */
426                 inode->i_ino = hash;
427 
428                 /* We can't support update_atime(), since the server will reset it */
429                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
430                 inode->i_mode = fattr->mode;
431                 if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
432                                 && nfs_server_capable(inode, NFS_CAP_MODE))
433                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
434                 /* Why so? Because we want revalidate for devices/FIFOs, and
435                  * that's precisely what we have in nfs_file_inode_operations.
436                  */
437                 inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
438                 if (S_ISREG(inode->i_mode)) {
439                         inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
440                         inode->i_data.a_ops = &nfs_file_aops;
441                 } else if (S_ISDIR(inode->i_mode)) {
442                         inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
443                         inode->i_fop = &nfs_dir_operations;
444                         inode->i_data.a_ops = &nfs_dir_aops;
445                         /* Deal with crossing mountpoints */
446                         if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
447                                         fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
448                                 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
449                                         inode->i_op = &nfs_referral_inode_operations;
450                                 else
451                                         inode->i_op = &nfs_mountpoint_inode_operations;
452                                 inode->i_fop = NULL;
453                                 inode->i_flags |= S_AUTOMOUNT;
454                         }
455                 } else if (S_ISLNK(inode->i_mode)) {
456                         inode->i_op = &nfs_symlink_inode_operations;
457                         inode_nohighmem(inode);
458                 } else
459                         init_special_inode(inode, inode->i_mode, fattr->rdev);
460 
461                 memset(&inode->i_atime, 0, sizeof(inode->i_atime));
462                 memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
463                 memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
464                 inode->i_version = 0;
465                 inode->i_size = 0;
466                 clear_nlink(inode);
467                 inode->i_uid = make_kuid(&init_user_ns, -2);
468                 inode->i_gid = make_kgid(&init_user_ns, -2);
469                 inode->i_blocks = 0;
470                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
471                 nfsi->write_io = 0;
472                 nfsi->read_io = 0;
473 
474                 nfsi->read_cache_jiffies = fattr->time_start;
475                 nfsi->attr_gencount = fattr->gencount;
476                 if (fattr->valid & NFS_ATTR_FATTR_ATIME)
477                         inode->i_atime = fattr->atime;
478                 else if (nfs_server_capable(inode, NFS_CAP_ATIME))
479                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
480                 if (fattr->valid & NFS_ATTR_FATTR_MTIME)
481                         inode->i_mtime = fattr->mtime;
482                 else if (nfs_server_capable(inode, NFS_CAP_MTIME))
483                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
484                 if (fattr->valid & NFS_ATTR_FATTR_CTIME)
485                         inode->i_ctime = fattr->ctime;
486                 else if (nfs_server_capable(inode, NFS_CAP_CTIME))
487                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
488                 if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
489                         inode->i_version = fattr->change_attr;
490                 else
491                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
492                                 | NFS_INO_REVAL_PAGECACHE);
493                 if (fattr->valid & NFS_ATTR_FATTR_SIZE)
494                         inode->i_size = nfs_size_to_loff_t(fattr->size);
495                 else
496                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
497                                 | NFS_INO_REVAL_PAGECACHE);
498                 if (fattr->valid & NFS_ATTR_FATTR_NLINK)
499                         set_nlink(inode, fattr->nlink);
500                 else if (nfs_server_capable(inode, NFS_CAP_NLINK))
501                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
502                 if (fattr->valid & NFS_ATTR_FATTR_OWNER)
503                         inode->i_uid = fattr->uid;
504                 else if (nfs_server_capable(inode, NFS_CAP_OWNER))
505                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
506                 if (fattr->valid & NFS_ATTR_FATTR_GROUP)
507                         inode->i_gid = fattr->gid;
508                 else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
509                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
510                 if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
511                         inode->i_blocks = fattr->du.nfs2.blocks;
512                 if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
513                         /*
514                          * report the blocks in 512byte units
515                          */
516                         inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
517                 }
518 
519                 nfs_setsecurity(inode, fattr, label);
520 
521                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
522                 nfsi->attrtimeo_timestamp = now;
523                 nfsi->access_cache = RB_ROOT;
524 
525                 nfs_fscache_init_inode(inode);
526 
527                 unlock_new_inode(inode);
528         } else
529                 nfs_refresh_inode(inode, fattr);
530         dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
531                 inode->i_sb->s_id,
532                 (unsigned long long)NFS_FILEID(inode),
533                 nfs_display_fhandle_hash(fh),
534                 atomic_read(&inode->i_count));
535 
536 out:
537         return inode;
538 
539 out_no_inode:
540         dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
541         goto out;
542 }
543 EXPORT_SYMBOL_GPL(nfs_fhget);
544 
545 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE|ATTR_OPEN)
546 
547 int
548 nfs_setattr(struct dentry *dentry, struct iattr *attr)
549 {
550         struct inode *inode = d_inode(dentry);
551         struct nfs_fattr *fattr;
552         int error = 0;
553 
554         nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
555 
556         /* skip mode change if it's just for clearing setuid/setgid */
557         if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
558                 attr->ia_valid &= ~ATTR_MODE;
559 
560         if (attr->ia_valid & ATTR_SIZE) {
561                 BUG_ON(!S_ISREG(inode->i_mode));
562 
563                 error = inode_newsize_ok(inode, attr->ia_size);
564                 if (error)
565                         return error;
566 
567                 if (attr->ia_size == i_size_read(inode))
568                         attr->ia_valid &= ~ATTR_SIZE;
569         }
570 
571         /* Optimization: if the end result is no change, don't RPC */
572         attr->ia_valid &= NFS_VALID_ATTRS;
573         if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
574                 return 0;
575 
576         trace_nfs_setattr_enter(inode);
577 
578         /* Write all dirty data */
579         if (S_ISREG(inode->i_mode))
580                 nfs_sync_inode(inode);
581 
582         fattr = nfs_alloc_fattr();
583         if (fattr == NULL) {
584                 error = -ENOMEM;
585                 goto out;
586         }
587 
588         /*
589          * Return any delegations if we're going to change ACLs
590          */
591         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
592                 NFS_PROTO(inode)->return_delegation(inode);
593         error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
594         if (error == 0)
595                 error = nfs_refresh_inode(inode, fattr);
596         nfs_free_fattr(fattr);
597 out:
598         trace_nfs_setattr_exit(inode, error);
599         return error;
600 }
601 EXPORT_SYMBOL_GPL(nfs_setattr);
602 
603 /**
604  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
605  * @inode: inode of the file used
606  * @offset: file offset to start truncating
607  *
608  * This is a copy of the common vmtruncate, but with the locking
609  * corrected to take into account the fact that NFS requires
610  * inode->i_size to be updated under the inode->i_lock.
611  * Note: must be called with inode->i_lock held!
612  */
613 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
614 {
615         int err;
616 
617         err = inode_newsize_ok(inode, offset);
618         if (err)
619                 goto out;
620 
621         i_size_write(inode, offset);
622         /* Optimisation */
623         if (offset == 0)
624                 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
625 
626         spin_unlock(&inode->i_lock);
627         truncate_pagecache(inode, offset);
628         spin_lock(&inode->i_lock);
629 out:
630         return err;
631 }
632 
633 /**
634  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
635  * @inode: pointer to struct inode
636  * @attr: pointer to struct iattr
637  *
638  * Note: we do this in the *proc.c in order to ensure that
639  *       it works for things like exclusive creates too.
640  */
641 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
642                 struct nfs_fattr *fattr)
643 {
644         /* Barrier: bump the attribute generation count. */
645         nfs_fattr_set_barrier(fattr);
646 
647         spin_lock(&inode->i_lock);
648         NFS_I(inode)->attr_gencount = fattr->gencount;
649         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
650                 if ((attr->ia_valid & ATTR_MODE) != 0) {
651                         int mode = attr->ia_mode & S_IALLUGO;
652                         mode |= inode->i_mode & ~S_IALLUGO;
653                         inode->i_mode = mode;
654                 }
655                 if ((attr->ia_valid & ATTR_UID) != 0)
656                         inode->i_uid = attr->ia_uid;
657                 if ((attr->ia_valid & ATTR_GID) != 0)
658                         inode->i_gid = attr->ia_gid;
659                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
660                                 | NFS_INO_INVALID_ACL);
661         }
662         if ((attr->ia_valid & ATTR_SIZE) != 0) {
663                 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
664                 nfs_vmtruncate(inode, attr->ia_size);
665         }
666         if (fattr->valid)
667                 nfs_update_inode(inode, fattr);
668         else
669                 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
670         spin_unlock(&inode->i_lock);
671 }
672 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
673 
674 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
675 {
676         struct dentry *parent;
677 
678         if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
679                 return;
680         parent = dget_parent(dentry);
681         nfs_force_use_readdirplus(d_inode(parent));
682         dput(parent);
683 }
684 
685 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
686 {
687         struct dentry *parent;
688 
689         if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
690                 return;
691         parent = dget_parent(dentry);
692         nfs_advise_use_readdirplus(d_inode(parent));
693         dput(parent);
694 }
695 
696 static bool nfs_need_revalidate_inode(struct inode *inode)
697 {
698         if (NFS_I(inode)->cache_validity &
699                         (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
700                 return true;
701         if (nfs_attribute_cache_expired(inode))
702                 return true;
703         return false;
704 }
705 
706 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
707 {
708         struct inode *inode = d_inode(dentry);
709         int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
710         int err = 0;
711 
712         trace_nfs_getattr_enter(inode);
713         /* Flush out writes to the server in order to update c/mtime.  */
714         if (S_ISREG(inode->i_mode)) {
715                 err = filemap_write_and_wait(inode->i_mapping);
716                 if (err)
717                         goto out;
718         }
719 
720         /*
721          * We may force a getattr if the user cares about atime.
722          *
723          * Note that we only have to check the vfsmount flags here:
724          *  - NFS always sets S_NOATIME by so checking it would give a
725          *    bogus result
726          *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
727          *    no point in checking those.
728          */
729         if ((mnt->mnt_flags & MNT_NOATIME) ||
730             ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
731                 need_atime = 0;
732 
733         if (need_atime || nfs_need_revalidate_inode(inode)) {
734                 struct nfs_server *server = NFS_SERVER(inode);
735 
736                 nfs_readdirplus_parent_cache_miss(dentry);
737                 err = __nfs_revalidate_inode(server, inode);
738         } else
739                 nfs_readdirplus_parent_cache_hit(dentry);
740         if (!err) {
741                 generic_fillattr(inode, stat);
742                 stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
743                 if (S_ISDIR(inode->i_mode))
744                         stat->blksize = NFS_SERVER(inode)->dtsize;
745         }
746 out:
747         trace_nfs_getattr_exit(inode, err);
748         return err;
749 }
750 EXPORT_SYMBOL_GPL(nfs_getattr);
751 
752 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
753 {
754         atomic_set(&l_ctx->count, 1);
755         l_ctx->lockowner = current->files;
756         INIT_LIST_HEAD(&l_ctx->list);
757         atomic_set(&l_ctx->io_count, 0);
758 }
759 
760 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
761 {
762         struct nfs_lock_context *head = &ctx->lock_context;
763         struct nfs_lock_context *pos = head;
764 
765         do {
766                 if (pos->lockowner != current->files)
767                         continue;
768                 atomic_inc(&pos->count);
769                 return pos;
770         } while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
771         return NULL;
772 }
773 
774 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
775 {
776         struct nfs_lock_context *res, *new = NULL;
777         struct inode *inode = d_inode(ctx->dentry);
778 
779         spin_lock(&inode->i_lock);
780         res = __nfs_find_lock_context(ctx);
781         if (res == NULL) {
782                 spin_unlock(&inode->i_lock);
783                 new = kmalloc(sizeof(*new), GFP_KERNEL);
784                 if (new == NULL)
785                         return ERR_PTR(-ENOMEM);
786                 nfs_init_lock_context(new);
787                 spin_lock(&inode->i_lock);
788                 res = __nfs_find_lock_context(ctx);
789                 if (res == NULL) {
790                         list_add_tail(&new->list, &ctx->lock_context.list);
791                         new->open_context = ctx;
792                         res = new;
793                         new = NULL;
794                 }
795         }
796         spin_unlock(&inode->i_lock);
797         kfree(new);
798         return res;
799 }
800 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
801 
802 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
803 {
804         struct nfs_open_context *ctx = l_ctx->open_context;
805         struct inode *inode = d_inode(ctx->dentry);
806 
807         if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
808                 return;
809         list_del(&l_ctx->list);
810         spin_unlock(&inode->i_lock);
811         kfree(l_ctx);
812 }
813 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
814 
815 /**
816  * nfs_close_context - Common close_context() routine NFSv2/v3
817  * @ctx: pointer to context
818  * @is_sync: is this a synchronous close
819  *
820  * Ensure that the attributes are up to date if we're mounted
821  * with close-to-open semantics and we have cached data that will
822  * need to be revalidated on open.
823  */
824 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
825 {
826         struct nfs_inode *nfsi;
827         struct inode *inode;
828         struct nfs_server *server;
829 
830         if (!(ctx->mode & FMODE_WRITE))
831                 return;
832         if (!is_sync)
833                 return;
834         inode = d_inode(ctx->dentry);
835         if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
836                 return;
837         nfsi = NFS_I(inode);
838         if (inode->i_mapping->nrpages == 0)
839                 return;
840         if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
841                 return;
842         if (!list_empty(&nfsi->open_files))
843                 return;
844         server = NFS_SERVER(inode);
845         if (server->flags & NFS_MOUNT_NOCTO)
846                 return;
847         nfs_revalidate_inode(server, inode);
848 }
849 EXPORT_SYMBOL_GPL(nfs_close_context);
850 
851 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
852                                                 fmode_t f_mode,
853                                                 struct file *filp)
854 {
855         struct nfs_open_context *ctx;
856         struct rpc_cred *cred = rpc_lookup_cred();
857         if (IS_ERR(cred))
858                 return ERR_CAST(cred);
859 
860         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
861         if (!ctx) {
862                 put_rpccred(cred);
863                 return ERR_PTR(-ENOMEM);
864         }
865         nfs_sb_active(dentry->d_sb);
866         ctx->dentry = dget(dentry);
867         ctx->cred = cred;
868         ctx->state = NULL;
869         ctx->mode = f_mode;
870         ctx->flags = 0;
871         ctx->error = 0;
872         ctx->flock_owner = (fl_owner_t)filp;
873         nfs_init_lock_context(&ctx->lock_context);
874         ctx->lock_context.open_context = ctx;
875         INIT_LIST_HEAD(&ctx->list);
876         ctx->mdsthreshold = NULL;
877         return ctx;
878 }
879 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
880 
881 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
882 {
883         if (ctx != NULL)
884                 atomic_inc(&ctx->lock_context.count);
885         return ctx;
886 }
887 EXPORT_SYMBOL_GPL(get_nfs_open_context);
888 
889 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
890 {
891         struct inode *inode = d_inode(ctx->dentry);
892         struct super_block *sb = ctx->dentry->d_sb;
893 
894         if (!list_empty(&ctx->list)) {
895                 if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
896                         return;
897                 list_del(&ctx->list);
898                 spin_unlock(&inode->i_lock);
899         } else if (!atomic_dec_and_test(&ctx->lock_context.count))
900                 return;
901         if (inode != NULL)
902                 NFS_PROTO(inode)->close_context(ctx, is_sync);
903         if (ctx->cred != NULL)
904                 put_rpccred(ctx->cred);
905         dput(ctx->dentry);
906         nfs_sb_deactive(sb);
907         kfree(ctx->mdsthreshold);
908         kfree(ctx);
909 }
910 
911 void put_nfs_open_context(struct nfs_open_context *ctx)
912 {
913         __put_nfs_open_context(ctx, 0);
914 }
915 EXPORT_SYMBOL_GPL(put_nfs_open_context);
916 
917 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
918 {
919         __put_nfs_open_context(ctx, 1);
920 }
921 
922 /*
923  * Ensure that mmap has a recent RPC credential for use when writing out
924  * shared pages
925  */
926 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
927 {
928         struct inode *inode = d_inode(ctx->dentry);
929         struct nfs_inode *nfsi = NFS_I(inode);
930 
931         spin_lock(&inode->i_lock);
932         if (ctx->mode & FMODE_WRITE)
933                 list_add(&ctx->list, &nfsi->open_files);
934         else
935                 list_add_tail(&ctx->list, &nfsi->open_files);
936         spin_unlock(&inode->i_lock);
937 }
938 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
939 
940 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
941 {
942         filp->private_data = get_nfs_open_context(ctx);
943         if (list_empty(&ctx->list))
944                 nfs_inode_attach_open_context(ctx);
945 }
946 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
947 
948 /*
949  * Given an inode, search for an open context with the desired characteristics
950  */
951 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
952 {
953         struct nfs_inode *nfsi = NFS_I(inode);
954         struct nfs_open_context *pos, *ctx = NULL;
955 
956         spin_lock(&inode->i_lock);
957         list_for_each_entry(pos, &nfsi->open_files, list) {
958                 if (cred != NULL && pos->cred != cred)
959                         continue;
960                 if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
961                         continue;
962                 ctx = get_nfs_open_context(pos);
963                 break;
964         }
965         spin_unlock(&inode->i_lock);
966         return ctx;
967 }
968 
969 void nfs_file_clear_open_context(struct file *filp)
970 {
971         struct nfs_open_context *ctx = nfs_file_open_context(filp);
972 
973         if (ctx) {
974                 struct inode *inode = d_inode(ctx->dentry);
975 
976                 /*
977                  * We fatal error on write before. Try to writeback
978                  * every page again.
979                  */
980                 if (ctx->error < 0)
981                         invalidate_inode_pages2(inode->i_mapping);
982                 filp->private_data = NULL;
983                 spin_lock(&inode->i_lock);
984                 list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
985                 spin_unlock(&inode->i_lock);
986                 put_nfs_open_context_sync(ctx);
987         }
988 }
989 
990 /*
991  * These allocate and release file read/write context information.
992  */
993 int nfs_open(struct inode *inode, struct file *filp)
994 {
995         struct nfs_open_context *ctx;
996 
997         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
998         if (IS_ERR(ctx))
999                 return PTR_ERR(ctx);
1000         nfs_file_set_open_context(filp, ctx);
1001         put_nfs_open_context(ctx);
1002         nfs_fscache_open_file(inode, filp);
1003         return 0;
1004 }
1005 
1006 /*
1007  * This function is called whenever some part of NFS notices that
1008  * the cached attributes have to be refreshed.
1009  */
1010 int
1011 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1012 {
1013         int              status = -ESTALE;
1014         struct nfs4_label *label = NULL;
1015         struct nfs_fattr *fattr = NULL;
1016         struct nfs_inode *nfsi = NFS_I(inode);
1017 
1018         dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1019                 inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1020 
1021         trace_nfs_revalidate_inode_enter(inode);
1022 
1023         if (is_bad_inode(inode))
1024                 goto out;
1025         if (NFS_STALE(inode))
1026                 goto out;
1027 
1028         /* pNFS: Attributes aren't updated until we layoutcommit */
1029         if (S_ISREG(inode->i_mode)) {
1030                 status = pnfs_sync_inode(inode, false);
1031                 if (status)
1032                         goto out;
1033         }
1034 
1035         status = -ENOMEM;
1036         fattr = nfs_alloc_fattr();
1037         if (fattr == NULL)
1038                 goto out;
1039 
1040         nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1041 
1042         label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1043         if (IS_ERR(label)) {
1044                 status = PTR_ERR(label);
1045                 goto out;
1046         }
1047 
1048         status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, label);
1049         if (status != 0) {
1050                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1051                          inode->i_sb->s_id,
1052                          (unsigned long long)NFS_FILEID(inode), status);
1053                 if (status == -ESTALE) {
1054                         nfs_zap_caches(inode);
1055                         if (!S_ISDIR(inode->i_mode))
1056                                 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1057                 }
1058                 goto err_out;
1059         }
1060 
1061         status = nfs_refresh_inode(inode, fattr);
1062         if (status) {
1063                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1064                          inode->i_sb->s_id,
1065                          (unsigned long long)NFS_FILEID(inode), status);
1066                 goto err_out;
1067         }
1068 
1069         if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1070                 nfs_zap_acl_cache(inode);
1071 
1072         nfs_setsecurity(inode, fattr, label);
1073 
1074         dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1075                 inode->i_sb->s_id,
1076                 (unsigned long long)NFS_FILEID(inode));
1077 
1078 err_out:
1079         nfs4_label_free(label);
1080 out:
1081         nfs_free_fattr(fattr);
1082         trace_nfs_revalidate_inode_exit(inode, status);
1083         return status;
1084 }
1085 
1086 int nfs_attribute_cache_expired(struct inode *inode)
1087 {
1088         if (nfs_have_delegated_attributes(inode))
1089                 return 0;
1090         return nfs_attribute_timeout(inode);
1091 }
1092 
1093 /**
1094  * nfs_revalidate_inode - Revalidate the inode attributes
1095  * @server - pointer to nfs_server struct
1096  * @inode - pointer to inode struct
1097  *
1098  * Updates inode attribute information by retrieving the data from the server.
1099  */
1100 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1101 {
1102         if (!nfs_need_revalidate_inode(inode))
1103                 return NFS_STALE(inode) ? -ESTALE : 0;
1104         return __nfs_revalidate_inode(server, inode);
1105 }
1106 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1107 
1108 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1109 {
1110         struct nfs_inode *nfsi = NFS_I(inode);
1111         int ret;
1112 
1113         if (mapping->nrpages != 0) {
1114                 if (S_ISREG(inode->i_mode)) {
1115                         unmap_mapping_range(mapping, 0, 0, 0);
1116                         ret = nfs_sync_mapping(mapping);
1117                         if (ret < 0)
1118                                 return ret;
1119                 }
1120                 ret = invalidate_inode_pages2(mapping);
1121                 if (ret < 0)
1122                         return ret;
1123         }
1124         if (S_ISDIR(inode->i_mode)) {
1125                 spin_lock(&inode->i_lock);
1126                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1127                 spin_unlock(&inode->i_lock);
1128         }
1129         nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1130         nfs_fscache_wait_on_invalidate(inode);
1131 
1132         dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1133                         inode->i_sb->s_id,
1134                         (unsigned long long)NFS_FILEID(inode));
1135         return 0;
1136 }
1137 
1138 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1139 {
1140         return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1141                 NFS_STALE(inode);
1142 }
1143 
1144 int nfs_revalidate_mapping_rcu(struct inode *inode)
1145 {
1146         struct nfs_inode *nfsi = NFS_I(inode);
1147         unsigned long *bitlock = &nfsi->flags;
1148         int ret = 0;
1149 
1150         if (IS_SWAPFILE(inode))
1151                 goto out;
1152         if (nfs_mapping_need_revalidate_inode(inode)) {
1153                 ret = -ECHILD;
1154                 goto out;
1155         }
1156         spin_lock(&inode->i_lock);
1157         if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1158             (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1159                 ret = -ECHILD;
1160         spin_unlock(&inode->i_lock);
1161 out:
1162         return ret;
1163 }
1164 
1165 /**
1166  * nfs_revalidate_mapping - Revalidate the pagecache
1167  * @inode - pointer to host inode
1168  * @mapping - pointer to mapping
1169  */
1170 int nfs_revalidate_mapping(struct inode *inode,
1171                 struct address_space *mapping)
1172 {
1173         struct nfs_inode *nfsi = NFS_I(inode);
1174         unsigned long *bitlock = &nfsi->flags;
1175         int ret = 0;
1176 
1177         /* swapfiles are not supposed to be shared. */
1178         if (IS_SWAPFILE(inode))
1179                 goto out;
1180 
1181         if (nfs_mapping_need_revalidate_inode(inode)) {
1182                 ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1183                 if (ret < 0)
1184                         goto out;
1185         }
1186 
1187         /*
1188          * We must clear NFS_INO_INVALID_DATA first to ensure that
1189          * invalidations that come in while we're shooting down the mappings
1190          * are respected. But, that leaves a race window where one revalidator
1191          * can clear the flag, and then another checks it before the mapping
1192          * gets invalidated. Fix that by serializing access to this part of
1193          * the function.
1194          *
1195          * At the same time, we need to allow other tasks to see whether we
1196          * might be in the middle of invalidating the pages, so we only set
1197          * the bit lock here if it looks like we're going to be doing that.
1198          */
1199         for (;;) {
1200                 ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1201                                          nfs_wait_bit_killable, TASK_KILLABLE);
1202                 if (ret)
1203                         goto out;
1204                 spin_lock(&inode->i_lock);
1205                 if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1206                         spin_unlock(&inode->i_lock);
1207                         continue;
1208                 }
1209                 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1210                         break;
1211                 spin_unlock(&inode->i_lock);
1212                 goto out;
1213         }
1214 
1215         set_bit(NFS_INO_INVALIDATING, bitlock);
1216         smp_wmb();
1217         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1218         spin_unlock(&inode->i_lock);
1219         trace_nfs_invalidate_mapping_enter(inode);
1220         ret = nfs_invalidate_mapping(inode, mapping);
1221         trace_nfs_invalidate_mapping_exit(inode, ret);
1222 
1223         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1224         smp_mb__after_atomic();
1225         wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1226 out:
1227         return ret;
1228 }
1229 
1230 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1231 {
1232         struct inode *inode = &nfsi->vfs_inode;
1233 
1234         assert_spin_locked(&inode->i_lock);
1235 
1236         if (!S_ISREG(inode->i_mode))
1237                 return false;
1238         if (list_empty(&nfsi->open_files))
1239                 return false;
1240         /* Note: This relies on nfsi->open_files being ordered with writers
1241          *       being placed at the head of the list.
1242          *       See nfs_inode_attach_open_context()
1243          */
1244         return (list_first_entry(&nfsi->open_files,
1245                         struct nfs_open_context,
1246                         list)->mode & FMODE_WRITE) == FMODE_WRITE;
1247 }
1248 
1249 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1250 {
1251         return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1252 }
1253 
1254 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1255 {
1256         struct nfs_inode *nfsi = NFS_I(inode);
1257         unsigned long ret = 0;
1258 
1259         if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1260                         && (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1261                         && inode->i_version == fattr->pre_change_attr) {
1262                 inode->i_version = fattr->change_attr;
1263                 if (S_ISDIR(inode->i_mode))
1264                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1265                 ret |= NFS_INO_INVALID_ATTR;
1266         }
1267         /* If we have atomic WCC data, we may update some attributes */
1268         if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1269                         && (fattr->valid & NFS_ATTR_FATTR_CTIME)
1270                         && timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1271                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1272                 ret |= NFS_INO_INVALID_ATTR;
1273         }
1274 
1275         if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1276                         && (fattr->valid & NFS_ATTR_FATTR_MTIME)
1277                         && timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1278                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1279                 if (S_ISDIR(inode->i_mode))
1280                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1281                 ret |= NFS_INO_INVALID_ATTR;
1282         }
1283         if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1284                         && (fattr->valid & NFS_ATTR_FATTR_SIZE)
1285                         && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1286                         && nfsi->nrequests == 0) {
1287                 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1288                 ret |= NFS_INO_INVALID_ATTR;
1289         }
1290 
1291         return ret;
1292 }
1293 
1294 /**
1295  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1296  * @inode - pointer to inode
1297  * @fattr - updated attributes
1298  *
1299  * Verifies the attribute cache. If we have just changed the attributes,
1300  * so that fattr carries weak cache consistency data, then it may
1301  * also update the ctime/mtime/change_attribute.
1302  */
1303 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1304 {
1305         struct nfs_inode *nfsi = NFS_I(inode);
1306         loff_t cur_size, new_isize;
1307         unsigned long invalid = 0;
1308 
1309 
1310         if (nfs_have_delegated_attributes(inode))
1311                 return 0;
1312         /* Has the inode gone and changed behind our back? */
1313         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1314                 return -EIO;
1315         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1316                 return -EIO;
1317 
1318         if (!nfs_file_has_buffered_writers(nfsi)) {
1319                 /* Verify a few of the more important attributes */
1320                 if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && inode->i_version != fattr->change_attr)
1321                         invalid |= NFS_INO_INVALID_ATTR | NFS_INO_REVAL_PAGECACHE;
1322 
1323                 if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1324                         invalid |= NFS_INO_INVALID_ATTR;
1325 
1326                 if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
1327                         invalid |= NFS_INO_INVALID_ATTR;
1328 
1329                 if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1330                         cur_size = i_size_read(inode);
1331                         new_isize = nfs_size_to_loff_t(fattr->size);
1332                         if (cur_size != new_isize)
1333                                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1334                 }
1335         }
1336 
1337         /* Have any file permissions changed? */
1338         if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1339                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1340         if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1341                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1342         if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1343                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1344 
1345         /* Has the link count changed? */
1346         if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1347                 invalid |= NFS_INO_INVALID_ATTR;
1348 
1349         if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1350                 invalid |= NFS_INO_INVALID_ATIME;
1351 
1352         if (invalid != 0)
1353                 nfs_set_cache_invalid(inode, invalid | NFS_INO_REVAL_FORCED);
1354 
1355         nfsi->read_cache_jiffies = fattr->time_start;
1356         return 0;
1357 }
1358 
1359 static atomic_long_t nfs_attr_generation_counter;
1360 
1361 static unsigned long nfs_read_attr_generation_counter(void)
1362 {
1363         return atomic_long_read(&nfs_attr_generation_counter);
1364 }
1365 
1366 unsigned long nfs_inc_attr_generation_counter(void)
1367 {
1368         return atomic_long_inc_return(&nfs_attr_generation_counter);
1369 }
1370 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1371 
1372 void nfs_fattr_init(struct nfs_fattr *fattr)
1373 {
1374         fattr->valid = 0;
1375         fattr->time_start = jiffies;
1376         fattr->gencount = nfs_inc_attr_generation_counter();
1377         fattr->owner_name = NULL;
1378         fattr->group_name = NULL;
1379 }
1380 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1381 
1382 /**
1383  * nfs_fattr_set_barrier
1384  * @fattr: attributes
1385  *
1386  * Used to set a barrier after an attribute was updated. This
1387  * barrier ensures that older attributes from RPC calls that may
1388  * have raced with our update cannot clobber these new values.
1389  * Note that you are still responsible for ensuring that other
1390  * operations which change the attribute on the server do not
1391  * collide.
1392  */
1393 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1394 {
1395         fattr->gencount = nfs_inc_attr_generation_counter();
1396 }
1397 
1398 struct nfs_fattr *nfs_alloc_fattr(void)
1399 {
1400         struct nfs_fattr *fattr;
1401 
1402         fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1403         if (fattr != NULL)
1404                 nfs_fattr_init(fattr);
1405         return fattr;
1406 }
1407 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1408 
1409 struct nfs_fh *nfs_alloc_fhandle(void)
1410 {
1411         struct nfs_fh *fh;
1412 
1413         fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1414         if (fh != NULL)
1415                 fh->size = 0;
1416         return fh;
1417 }
1418 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1419 
1420 #ifdef NFS_DEBUG
1421 /*
1422  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1423  *                             in the same way that wireshark does
1424  *
1425  * @fh: file handle
1426  *
1427  * For debugging only.
1428  */
1429 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1430 {
1431         /* wireshark uses 32-bit AUTODIN crc and does a bitwise
1432          * not on the result */
1433         return nfs_fhandle_hash(fh);
1434 }
1435 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1436 
1437 /*
1438  * _nfs_display_fhandle - display an NFS file handle on the console
1439  *
1440  * @fh: file handle to display
1441  * @caption: display caption
1442  *
1443  * For debugging only.
1444  */
1445 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1446 {
1447         unsigned short i;
1448 
1449         if (fh == NULL || fh->size == 0) {
1450                 printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1451                 return;
1452         }
1453 
1454         printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1455                caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1456         for (i = 0; i < fh->size; i += 16) {
1457                 __be32 *pos = (__be32 *)&fh->data[i];
1458 
1459                 switch ((fh->size - i - 1) >> 2) {
1460                 case 0:
1461                         printk(KERN_DEFAULT " %08x\n",
1462                                 be32_to_cpup(pos));
1463                         break;
1464                 case 1:
1465                         printk(KERN_DEFAULT " %08x %08x\n",
1466                                 be32_to_cpup(pos), be32_to_cpup(pos + 1));
1467                         break;
1468                 case 2:
1469                         printk(KERN_DEFAULT " %08x %08x %08x\n",
1470                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1471                                 be32_to_cpup(pos + 2));
1472                         break;
1473                 default:
1474                         printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1475                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1476                                 be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1477                 }
1478         }
1479 }
1480 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1481 #endif
1482 
1483 /**
1484  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1485  * @inode - pointer to inode
1486  * @fattr - attributes
1487  *
1488  * Attempt to divine whether or not an RPC call reply carrying stale
1489  * attributes got scheduled after another call carrying updated ones.
1490  *
1491  * To do so, the function first assumes that a more recent ctime means
1492  * that the attributes in fattr are newer, however it also attempt to
1493  * catch the case where ctime either didn't change, or went backwards
1494  * (if someone reset the clock on the server) by looking at whether
1495  * or not this RPC call was started after the inode was last updated.
1496  * Note also the check for wraparound of 'attr_gencount'
1497  *
1498  * The function returns 'true' if it thinks the attributes in 'fattr' are
1499  * more recent than the ones cached in the inode.
1500  *
1501  */
1502 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1503 {
1504         const struct nfs_inode *nfsi = NFS_I(inode);
1505 
1506         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1507                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1508 }
1509 
1510 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1511 {
1512         int ret;
1513 
1514         trace_nfs_refresh_inode_enter(inode);
1515 
1516         if (nfs_inode_attrs_need_update(inode, fattr))
1517                 ret = nfs_update_inode(inode, fattr);
1518         else
1519                 ret = nfs_check_inode_attributes(inode, fattr);
1520 
1521         trace_nfs_refresh_inode_exit(inode, ret);
1522         return ret;
1523 }
1524 
1525 /**
1526  * nfs_refresh_inode - try to update the inode attribute cache
1527  * @inode - pointer to inode
1528  * @fattr - updated attributes
1529  *
1530  * Check that an RPC call that returned attributes has not overlapped with
1531  * other recent updates of the inode metadata, then decide whether it is
1532  * safe to do a full update of the inode attributes, or whether just to
1533  * call nfs_check_inode_attributes.
1534  */
1535 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1536 {
1537         int status;
1538 
1539         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1540                 return 0;
1541         spin_lock(&inode->i_lock);
1542         status = nfs_refresh_inode_locked(inode, fattr);
1543         spin_unlock(&inode->i_lock);
1544 
1545         return status;
1546 }
1547 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1548 
1549 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1550 {
1551         unsigned long invalid = NFS_INO_INVALID_ATTR;
1552 
1553         if (S_ISDIR(inode->i_mode))
1554                 invalid |= NFS_INO_INVALID_DATA;
1555         nfs_set_cache_invalid(inode, invalid);
1556         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1557                 return 0;
1558         return nfs_refresh_inode_locked(inode, fattr);
1559 }
1560 
1561 /**
1562  * nfs_post_op_update_inode - try to update the inode attribute cache
1563  * @inode - pointer to inode
1564  * @fattr - updated attributes
1565  *
1566  * After an operation that has changed the inode metadata, mark the
1567  * attribute cache as being invalid, then try to update it.
1568  *
1569  * NB: if the server didn't return any post op attributes, this
1570  * function will force the retrieval of attributes before the next
1571  * NFS request.  Thus it should be used only for operations that
1572  * are expected to change one or more attributes, to avoid
1573  * unnecessary NFS requests and trips through nfs_update_inode().
1574  */
1575 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1576 {
1577         int status;
1578 
1579         spin_lock(&inode->i_lock);
1580         nfs_fattr_set_barrier(fattr);
1581         status = nfs_post_op_update_inode_locked(inode, fattr);
1582         spin_unlock(&inode->i_lock);
1583 
1584         return status;
1585 }
1586 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1587 
1588 /**
1589  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1590  * @inode - pointer to inode
1591  * @fattr - updated attributes
1592  *
1593  * After an operation that has changed the inode metadata, mark the
1594  * attribute cache as being invalid, then try to update it. Fake up
1595  * weak cache consistency data, if none exist.
1596  *
1597  * This function is mainly designed to be used by the ->write_done() functions.
1598  */
1599 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1600 {
1601         int status;
1602 
1603         /* Don't do a WCC update if these attributes are already stale */
1604         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1605                         !nfs_inode_attrs_need_update(inode, fattr)) {
1606                 fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1607                                 | NFS_ATTR_FATTR_PRESIZE
1608                                 | NFS_ATTR_FATTR_PREMTIME
1609                                 | NFS_ATTR_FATTR_PRECTIME);
1610                 goto out_noforce;
1611         }
1612         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1613                         (fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1614                 fattr->pre_change_attr = inode->i_version;
1615                 fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1616         }
1617         if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1618                         (fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1619                 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1620                 fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1621         }
1622         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1623                         (fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1624                 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1625                 fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1626         }
1627         if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1628                         (fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1629                 fattr->pre_size = i_size_read(inode);
1630                 fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1631         }
1632 out_noforce:
1633         status = nfs_post_op_update_inode_locked(inode, fattr);
1634         return status;
1635 }
1636 
1637 /**
1638  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1639  * @inode - pointer to inode
1640  * @fattr - updated attributes
1641  *
1642  * After an operation that has changed the inode metadata, mark the
1643  * attribute cache as being invalid, then try to update it. Fake up
1644  * weak cache consistency data, if none exist.
1645  *
1646  * This function is mainly designed to be used by the ->write_done() functions.
1647  */
1648 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1649 {
1650         int status;
1651 
1652         spin_lock(&inode->i_lock);
1653         nfs_fattr_set_barrier(fattr);
1654         status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1655         spin_unlock(&inode->i_lock);
1656         return status;
1657 }
1658 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1659 
1660 
1661 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1662                                     struct nfs_fattr *fattr)
1663 {
1664         bool ret1 = true, ret2 = true;
1665 
1666         if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1667                 ret1 = (nfsi->fileid == fattr->fileid);
1668         if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1669                 ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1670         return ret1 || ret2;
1671 }
1672 
1673 /*
1674  * Many nfs protocol calls return the new file attributes after
1675  * an operation.  Here we update the inode to reflect the state
1676  * of the server's inode.
1677  *
1678  * This is a bit tricky because we have to make sure all dirty pages
1679  * have been sent off to the server before calling invalidate_inode_pages.
1680  * To make sure no other process adds more write requests while we try
1681  * our best to flush them, we make them sleep during the attribute refresh.
1682  *
1683  * A very similar scenario holds for the dir cache.
1684  */
1685 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1686 {
1687         struct nfs_server *server;
1688         struct nfs_inode *nfsi = NFS_I(inode);
1689         loff_t cur_isize, new_isize;
1690         unsigned long invalid = 0;
1691         unsigned long now = jiffies;
1692         unsigned long save_cache_validity;
1693         bool have_writers = nfs_file_has_buffered_writers(nfsi);
1694         bool cache_revalidated = true;
1695 
1696         dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1697                         __func__, inode->i_sb->s_id, inode->i_ino,
1698                         nfs_display_fhandle_hash(NFS_FH(inode)),
1699                         atomic_read(&inode->i_count), fattr->valid);
1700 
1701         if (!nfs_fileid_valid(nfsi, fattr)) {
1702                 printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1703                         "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1704                         NFS_SERVER(inode)->nfs_client->cl_hostname,
1705                         inode->i_sb->s_id, (long long)nfsi->fileid,
1706                         (long long)fattr->fileid);
1707                 goto out_err;
1708         }
1709 
1710         /*
1711          * Make sure the inode's type hasn't changed.
1712          */
1713         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1714                 /*
1715                 * Big trouble! The inode has become a different object.
1716                 */
1717                 printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1718                                 __func__, inode->i_ino, inode->i_mode, fattr->mode);
1719                 goto out_err;
1720         }
1721 
1722         server = NFS_SERVER(inode);
1723         /* Update the fsid? */
1724         if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1725                         !nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1726                         !IS_AUTOMOUNT(inode))
1727                 server->fsid = fattr->fsid;
1728 
1729         /*
1730          * Update the read time so we don't revalidate too often.
1731          */
1732         nfsi->read_cache_jiffies = fattr->time_start;
1733 
1734         save_cache_validity = nfsi->cache_validity;
1735         nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1736                         | NFS_INO_INVALID_ATIME
1737                         | NFS_INO_REVAL_FORCED
1738                         | NFS_INO_REVAL_PAGECACHE);
1739 
1740         /* Do atomic weak cache consistency updates */
1741         invalid |= nfs_wcc_update_inode(inode, fattr);
1742 
1743         if (pnfs_layoutcommit_outstanding(inode)) {
1744                 nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1745                 cache_revalidated = false;
1746         }
1747 
1748         /* More cache consistency checks */
1749         if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1750                 if (inode->i_version != fattr->change_attr) {
1751                         dprintk("NFS: change_attr change on server for file %s/%ld\n",
1752                                         inode->i_sb->s_id, inode->i_ino);
1753                         /* Could it be a race with writeback? */
1754                         if (!have_writers) {
1755                                 invalid |= NFS_INO_INVALID_ATTR
1756                                         | NFS_INO_INVALID_DATA
1757                                         | NFS_INO_INVALID_ACCESS
1758                                         | NFS_INO_INVALID_ACL;
1759                                 if (S_ISDIR(inode->i_mode))
1760                                         nfs_force_lookup_revalidate(inode);
1761                         }
1762                         inode->i_version = fattr->change_attr;
1763                 }
1764         } else {
1765                 nfsi->cache_validity |= save_cache_validity;
1766                 cache_revalidated = false;
1767         }
1768 
1769         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1770                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1771         } else if (server->caps & NFS_CAP_MTIME) {
1772                 nfsi->cache_validity |= save_cache_validity &
1773                                 (NFS_INO_INVALID_ATTR
1774                                 | NFS_INO_REVAL_FORCED);
1775                 cache_revalidated = false;
1776         }
1777 
1778         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1779                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1780         } else if (server->caps & NFS_CAP_CTIME) {
1781                 nfsi->cache_validity |= save_cache_validity &
1782                                 (NFS_INO_INVALID_ATTR
1783                                 | NFS_INO_REVAL_FORCED);
1784                 cache_revalidated = false;
1785         }
1786 
1787         /* Check if our cached file size is stale */
1788         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1789                 new_isize = nfs_size_to_loff_t(fattr->size);
1790                 cur_isize = i_size_read(inode);
1791                 if (new_isize != cur_isize) {
1792                         /* Do we perhaps have any outstanding writes, or has
1793                          * the file grown beyond our last write? */
1794                         if (nfsi->nrequests == 0 || new_isize > cur_isize) {
1795                                 i_size_write(inode, new_isize);
1796                                 if (!have_writers)
1797                                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1798                         }
1799                         dprintk("NFS: isize change on server for file %s/%ld "
1800                                         "(%Ld to %Ld)\n",
1801                                         inode->i_sb->s_id,
1802                                         inode->i_ino,
1803                                         (long long)cur_isize,
1804                                         (long long)new_isize);
1805                 }
1806         } else {
1807                 nfsi->cache_validity |= save_cache_validity &
1808                                 (NFS_INO_INVALID_ATTR
1809                                 | NFS_INO_REVAL_PAGECACHE
1810                                 | NFS_INO_REVAL_FORCED);
1811                 cache_revalidated = false;
1812         }
1813 
1814 
1815         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1816                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1817         else if (server->caps & NFS_CAP_ATIME) {
1818                 nfsi->cache_validity |= save_cache_validity &
1819                                 (NFS_INO_INVALID_ATIME
1820                                 | NFS_INO_REVAL_FORCED);
1821                 cache_revalidated = false;
1822         }
1823 
1824         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1825                 if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1826                         umode_t newmode = inode->i_mode & S_IFMT;
1827                         newmode |= fattr->mode & S_IALLUGO;
1828                         inode->i_mode = newmode;
1829                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1830                 }
1831         } else if (server->caps & NFS_CAP_MODE) {
1832                 nfsi->cache_validity |= save_cache_validity &
1833                                 (NFS_INO_INVALID_ATTR
1834                                 | NFS_INO_INVALID_ACCESS
1835                                 | NFS_INO_INVALID_ACL
1836                                 | NFS_INO_REVAL_FORCED);
1837                 cache_revalidated = false;
1838         }
1839 
1840         if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1841                 if (!uid_eq(inode->i_uid, fattr->uid)) {
1842                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1843                         inode->i_uid = fattr->uid;
1844                 }
1845         } else if (server->caps & NFS_CAP_OWNER) {
1846                 nfsi->cache_validity |= save_cache_validity &
1847                                 (NFS_INO_INVALID_ATTR
1848                                 | NFS_INO_INVALID_ACCESS
1849                                 | NFS_INO_INVALID_ACL
1850                                 | NFS_INO_REVAL_FORCED);
1851                 cache_revalidated = false;
1852         }
1853 
1854         if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1855                 if (!gid_eq(inode->i_gid, fattr->gid)) {
1856                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1857                         inode->i_gid = fattr->gid;
1858                 }
1859         } else if (server->caps & NFS_CAP_OWNER_GROUP) {
1860                 nfsi->cache_validity |= save_cache_validity &
1861                                 (NFS_INO_INVALID_ATTR
1862                                 | NFS_INO_INVALID_ACCESS
1863                                 | NFS_INO_INVALID_ACL
1864                                 | NFS_INO_REVAL_FORCED);
1865                 cache_revalidated = false;
1866         }
1867 
1868         if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1869                 if (inode->i_nlink != fattr->nlink) {
1870                         invalid |= NFS_INO_INVALID_ATTR;
1871                         if (S_ISDIR(inode->i_mode))
1872                                 invalid |= NFS_INO_INVALID_DATA;
1873                         set_nlink(inode, fattr->nlink);
1874                 }
1875         } else if (server->caps & NFS_CAP_NLINK) {
1876                 nfsi->cache_validity |= save_cache_validity &
1877                                 (NFS_INO_INVALID_ATTR
1878                                 | NFS_INO_REVAL_FORCED);
1879                 cache_revalidated = false;
1880         }
1881 
1882         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1883                 /*
1884                  * report the blocks in 512byte units
1885                  */
1886                 inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1887         } else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1888                 inode->i_blocks = fattr->du.nfs2.blocks;
1889         else
1890                 cache_revalidated = false;
1891 
1892         /* Update attrtimeo value if we're out of the unstable period */
1893         if (invalid & NFS_INO_INVALID_ATTR) {
1894                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1895                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1896                 nfsi->attrtimeo_timestamp = now;
1897                 /* Set barrier to be more recent than all outstanding updates */
1898                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1899         } else {
1900                 if (cache_revalidated) {
1901                         if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
1902                                 nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1903                                 nfsi->attrtimeo <<= 1;
1904                                 if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
1905                                         nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1906                         }
1907                         nfsi->attrtimeo_timestamp = now;
1908                 }
1909                 /* Set the barrier to be more recent than this fattr */
1910                 if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
1911                         nfsi->attr_gencount = fattr->gencount;
1912         }
1913 
1914         /* Don't declare attrcache up to date if there were no attrs! */
1915         if (cache_revalidated)
1916                 invalid &= ~NFS_INO_INVALID_ATTR;
1917 
1918         /* Don't invalidate the data if we were to blame */
1919         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1920                                 || S_ISLNK(inode->i_mode)))
1921                 invalid &= ~NFS_INO_INVALID_DATA;
1922         if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1923                         (save_cache_validity & NFS_INO_REVAL_FORCED))
1924                 nfs_set_cache_invalid(inode, invalid);
1925 
1926         return 0;
1927  out_err:
1928         /*
1929          * No need to worry about unhashing the dentry, as the
1930          * lookup validation will know that the inode is bad.
1931          * (But we fall through to invalidate the caches.)
1932          */
1933         nfs_invalidate_inode(inode);
1934         return -ESTALE;
1935 }
1936 
1937 struct inode *nfs_alloc_inode(struct super_block *sb)
1938 {
1939         struct nfs_inode *nfsi;
1940         nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1941         if (!nfsi)
1942                 return NULL;
1943         nfsi->flags = 0UL;
1944         nfsi->cache_validity = 0UL;
1945 #if IS_ENABLED(CONFIG_NFS_V4)
1946         nfsi->nfs4_acl = NULL;
1947 #endif /* CONFIG_NFS_V4 */
1948         return &nfsi->vfs_inode;
1949 }
1950 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1951 
1952 static void nfs_i_callback(struct rcu_head *head)
1953 {
1954         struct inode *inode = container_of(head, struct inode, i_rcu);
1955         kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1956 }
1957 
1958 void nfs_destroy_inode(struct inode *inode)
1959 {
1960         call_rcu(&inode->i_rcu, nfs_i_callback);
1961 }
1962 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1963 
1964 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1965 {
1966 #if IS_ENABLED(CONFIG_NFS_V4)
1967         INIT_LIST_HEAD(&nfsi->open_states);
1968         nfsi->delegation = NULL;
1969         init_rwsem(&nfsi->rwsem);
1970         nfsi->layout = NULL;
1971 #endif
1972 }
1973 
1974 static void init_once(void *foo)
1975 {
1976         struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1977 
1978         inode_init_once(&nfsi->vfs_inode);
1979         INIT_LIST_HEAD(&nfsi->open_files);
1980         INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1981         INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1982         INIT_LIST_HEAD(&nfsi->commit_info.list);
1983         nfsi->nrequests = 0;
1984         nfsi->commit_info.ncommit = 0;
1985         atomic_set(&nfsi->commit_info.rpcs_out, 0);
1986         init_rwsem(&nfsi->rmdir_sem);
1987         nfs4_init_once(nfsi);
1988 }
1989 
1990 static int __init nfs_init_inodecache(void)
1991 {
1992         nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1993                                              sizeof(struct nfs_inode),
1994                                              0, (SLAB_RECLAIM_ACCOUNT|
1995                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1996                                              init_once);
1997         if (nfs_inode_cachep == NULL)
1998                 return -ENOMEM;
1999 
2000         return 0;
2001 }
2002 
2003 static void nfs_destroy_inodecache(void)
2004 {
2005         /*
2006          * Make sure all delayed rcu free inodes are flushed before we
2007          * destroy cache.
2008          */
2009         rcu_barrier();
2010         kmem_cache_destroy(nfs_inode_cachep);
2011 }
2012 
2013 struct workqueue_struct *nfsiod_workqueue;
2014 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2015 
2016 /*
2017  * start up the nfsiod workqueue
2018  */
2019 static int nfsiod_start(void)
2020 {
2021         struct workqueue_struct *wq;
2022         dprintk("RPC:       creating workqueue nfsiod\n");
2023         wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2024         if (wq == NULL)
2025                 return -ENOMEM;
2026         nfsiod_workqueue = wq;
2027         return 0;
2028 }
2029 
2030 /*
2031  * Destroy the nfsiod workqueue
2032  */
2033 static void nfsiod_stop(void)
2034 {
2035         struct workqueue_struct *wq;
2036 
2037         wq = nfsiod_workqueue;
2038         if (wq == NULL)
2039                 return;
2040         nfsiod_workqueue = NULL;
2041         destroy_workqueue(wq);
2042 }
2043 
2044 unsigned int nfs_net_id;
2045 EXPORT_SYMBOL_GPL(nfs_net_id);
2046 
2047 static int nfs_net_init(struct net *net)
2048 {
2049         nfs_clients_init(net);
2050         return nfs_fs_proc_net_init(net);
2051 }
2052 
2053 static void nfs_net_exit(struct net *net)
2054 {
2055         nfs_fs_proc_net_exit(net);
2056         nfs_cleanup_cb_ident_idr(net);
2057 }
2058 
2059 static struct pernet_operations nfs_net_ops = {
2060         .init = nfs_net_init,
2061         .exit = nfs_net_exit,
2062         .id   = &nfs_net_id,
2063         .size = sizeof(struct nfs_net),
2064 };
2065 
2066 /*
2067  * Initialize NFS
2068  */
2069 static int __init init_nfs_fs(void)
2070 {
2071         int err;
2072 
2073         err = register_pernet_subsys(&nfs_net_ops);
2074         if (err < 0)
2075                 goto out9;
2076 
2077         err = nfs_fscache_register();
2078         if (err < 0)
2079                 goto out8;
2080 
2081         err = nfsiod_start();
2082         if (err)
2083                 goto out7;
2084 
2085         err = nfs_fs_proc_init();
2086         if (err)
2087                 goto out6;
2088 
2089         err = nfs_init_nfspagecache();
2090         if (err)
2091                 goto out5;
2092 
2093         err = nfs_init_inodecache();
2094         if (err)
2095                 goto out4;
2096 
2097         err = nfs_init_readpagecache();
2098         if (err)
2099                 goto out3;
2100 
2101         err = nfs_init_writepagecache();
2102         if (err)
2103                 goto out2;
2104 
2105         err = nfs_init_directcache();
2106         if (err)
2107                 goto out1;
2108 
2109         rpc_proc_register(&init_net, &nfs_rpcstat);
2110 
2111         err = register_nfs_fs();
2112         if (err)
2113                 goto out0;
2114 
2115         return 0;
2116 out0:
2117         rpc_proc_unregister(&init_net, "nfs");
2118         nfs_destroy_directcache();
2119 out1:
2120         nfs_destroy_writepagecache();
2121 out2:
2122         nfs_destroy_readpagecache();
2123 out3:
2124         nfs_destroy_inodecache();
2125 out4:
2126         nfs_destroy_nfspagecache();
2127 out5:
2128         nfs_fs_proc_exit();
2129 out6:
2130         nfsiod_stop();
2131 out7:
2132         nfs_fscache_unregister();
2133 out8:
2134         unregister_pernet_subsys(&nfs_net_ops);
2135 out9:
2136         return err;
2137 }
2138 
2139 static void __exit exit_nfs_fs(void)
2140 {
2141         nfs_destroy_directcache();
2142         nfs_destroy_writepagecache();
2143         nfs_destroy_readpagecache();
2144         nfs_destroy_inodecache();
2145         nfs_destroy_nfspagecache();
2146         nfs_fscache_unregister();
2147         unregister_pernet_subsys(&nfs_net_ops);
2148         rpc_proc_unregister(&init_net, "nfs");
2149         unregister_nfs_fs();
2150         nfs_fs_proc_exit();
2151         nfsiod_stop();
2152 }
2153 
2154 /* Not quite true; I just maintain it */
2155 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2156 MODULE_LICENSE("GPL");
2157 module_param(enable_ino64, bool, 0644);
2158 
2159 module_init(init_nfs_fs)
2160 module_exit(exit_nfs_fs)
2161 

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