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TOMOYO Linux Cross Reference
Linux/fs/nfs/inode.c

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  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/signal.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(const struct path *path, struct kstat *stat,
707                 u32 request_mask, unsigned int query_flags)
708 {
709         struct inode *inode = d_inode(path->dentry);
710         int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
711         int err = 0;
712 
713         trace_nfs_getattr_enter(inode);
714         /* Flush out writes to the server in order to update c/mtime.  */
715         if (S_ISREG(inode->i_mode)) {
716                 err = filemap_write_and_wait(inode->i_mapping);
717                 if (err)
718                         goto out;
719         }
720 
721         /*
722          * We may force a getattr if the user cares about atime.
723          *
724          * Note that we only have to check the vfsmount flags here:
725          *  - NFS always sets S_NOATIME by so checking it would give a
726          *    bogus result
727          *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
728          *    no point in checking those.
729          */
730         if ((path->mnt->mnt_flags & MNT_NOATIME) ||
731             ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
732                 need_atime = 0;
733 
734         if (need_atime || nfs_need_revalidate_inode(inode)) {
735                 struct nfs_server *server = NFS_SERVER(inode);
736 
737                 nfs_readdirplus_parent_cache_miss(path->dentry);
738                 err = __nfs_revalidate_inode(server, inode);
739         } else
740                 nfs_readdirplus_parent_cache_hit(path->dentry);
741         if (!err) {
742                 generic_fillattr(inode, stat);
743                 stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
744                 if (S_ISDIR(inode->i_mode))
745                         stat->blksize = NFS_SERVER(inode)->dtsize;
746         }
747 out:
748         trace_nfs_getattr_exit(inode, err);
749         return err;
750 }
751 EXPORT_SYMBOL_GPL(nfs_getattr);
752 
753 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
754 {
755         atomic_set(&l_ctx->count, 1);
756         l_ctx->lockowner = current->files;
757         INIT_LIST_HEAD(&l_ctx->list);
758         atomic_set(&l_ctx->io_count, 0);
759 }
760 
761 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
762 {
763         struct nfs_lock_context *head = &ctx->lock_context;
764         struct nfs_lock_context *pos = head;
765 
766         do {
767                 if (pos->lockowner != current->files)
768                         continue;
769                 atomic_inc(&pos->count);
770                 return pos;
771         } while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
772         return NULL;
773 }
774 
775 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
776 {
777         struct nfs_lock_context *res, *new = NULL;
778         struct inode *inode = d_inode(ctx->dentry);
779 
780         spin_lock(&inode->i_lock);
781         res = __nfs_find_lock_context(ctx);
782         if (res == NULL) {
783                 spin_unlock(&inode->i_lock);
784                 new = kmalloc(sizeof(*new), GFP_KERNEL);
785                 if (new == NULL)
786                         return ERR_PTR(-ENOMEM);
787                 nfs_init_lock_context(new);
788                 spin_lock(&inode->i_lock);
789                 res = __nfs_find_lock_context(ctx);
790                 if (res == NULL) {
791                         list_add_tail(&new->list, &ctx->lock_context.list);
792                         new->open_context = ctx;
793                         res = new;
794                         new = NULL;
795                 }
796         }
797         spin_unlock(&inode->i_lock);
798         kfree(new);
799         return res;
800 }
801 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
802 
803 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
804 {
805         struct nfs_open_context *ctx = l_ctx->open_context;
806         struct inode *inode = d_inode(ctx->dentry);
807 
808         if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
809                 return;
810         list_del(&l_ctx->list);
811         spin_unlock(&inode->i_lock);
812         kfree(l_ctx);
813 }
814 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
815 
816 /**
817  * nfs_close_context - Common close_context() routine NFSv2/v3
818  * @ctx: pointer to context
819  * @is_sync: is this a synchronous close
820  *
821  * Ensure that the attributes are up to date if we're mounted
822  * with close-to-open semantics and we have cached data that will
823  * need to be revalidated on open.
824  */
825 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
826 {
827         struct nfs_inode *nfsi;
828         struct inode *inode;
829         struct nfs_server *server;
830 
831         if (!(ctx->mode & FMODE_WRITE))
832                 return;
833         if (!is_sync)
834                 return;
835         inode = d_inode(ctx->dentry);
836         if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
837                 return;
838         nfsi = NFS_I(inode);
839         if (inode->i_mapping->nrpages == 0)
840                 return;
841         if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
842                 return;
843         if (!list_empty(&nfsi->open_files))
844                 return;
845         server = NFS_SERVER(inode);
846         if (server->flags & NFS_MOUNT_NOCTO)
847                 return;
848         nfs_revalidate_inode(server, inode);
849 }
850 EXPORT_SYMBOL_GPL(nfs_close_context);
851 
852 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
853                                                 fmode_t f_mode,
854                                                 struct file *filp)
855 {
856         struct nfs_open_context *ctx;
857         struct rpc_cred *cred = rpc_lookup_cred();
858         if (IS_ERR(cred))
859                 return ERR_CAST(cred);
860 
861         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
862         if (!ctx) {
863                 put_rpccred(cred);
864                 return ERR_PTR(-ENOMEM);
865         }
866         nfs_sb_active(dentry->d_sb);
867         ctx->dentry = dget(dentry);
868         ctx->cred = cred;
869         ctx->state = NULL;
870         ctx->mode = f_mode;
871         ctx->flags = 0;
872         ctx->error = 0;
873         ctx->flock_owner = (fl_owner_t)filp;
874         nfs_init_lock_context(&ctx->lock_context);
875         ctx->lock_context.open_context = ctx;
876         INIT_LIST_HEAD(&ctx->list);
877         ctx->mdsthreshold = NULL;
878         return ctx;
879 }
880 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
881 
882 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
883 {
884         if (ctx != NULL)
885                 atomic_inc(&ctx->lock_context.count);
886         return ctx;
887 }
888 EXPORT_SYMBOL_GPL(get_nfs_open_context);
889 
890 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
891 {
892         struct inode *inode = d_inode(ctx->dentry);
893         struct super_block *sb = ctx->dentry->d_sb;
894 
895         if (!list_empty(&ctx->list)) {
896                 if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
897                         return;
898                 list_del(&ctx->list);
899                 spin_unlock(&inode->i_lock);
900         } else if (!atomic_dec_and_test(&ctx->lock_context.count))
901                 return;
902         if (inode != NULL)
903                 NFS_PROTO(inode)->close_context(ctx, is_sync);
904         if (ctx->cred != NULL)
905                 put_rpccred(ctx->cred);
906         dput(ctx->dentry);
907         nfs_sb_deactive(sb);
908         kfree(ctx->mdsthreshold);
909         kfree(ctx);
910 }
911 
912 void put_nfs_open_context(struct nfs_open_context *ctx)
913 {
914         __put_nfs_open_context(ctx, 0);
915 }
916 EXPORT_SYMBOL_GPL(put_nfs_open_context);
917 
918 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
919 {
920         __put_nfs_open_context(ctx, 1);
921 }
922 
923 /*
924  * Ensure that mmap has a recent RPC credential for use when writing out
925  * shared pages
926  */
927 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
928 {
929         struct inode *inode = d_inode(ctx->dentry);
930         struct nfs_inode *nfsi = NFS_I(inode);
931 
932         spin_lock(&inode->i_lock);
933         if (ctx->mode & FMODE_WRITE)
934                 list_add(&ctx->list, &nfsi->open_files);
935         else
936                 list_add_tail(&ctx->list, &nfsi->open_files);
937         spin_unlock(&inode->i_lock);
938 }
939 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
940 
941 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
942 {
943         filp->private_data = get_nfs_open_context(ctx);
944         if (list_empty(&ctx->list))
945                 nfs_inode_attach_open_context(ctx);
946 }
947 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
948 
949 /*
950  * Given an inode, search for an open context with the desired characteristics
951  */
952 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
953 {
954         struct nfs_inode *nfsi = NFS_I(inode);
955         struct nfs_open_context *pos, *ctx = NULL;
956 
957         spin_lock(&inode->i_lock);
958         list_for_each_entry(pos, &nfsi->open_files, list) {
959                 if (cred != NULL && pos->cred != cred)
960                         continue;
961                 if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
962                         continue;
963                 ctx = get_nfs_open_context(pos);
964                 break;
965         }
966         spin_unlock(&inode->i_lock);
967         return ctx;
968 }
969 
970 void nfs_file_clear_open_context(struct file *filp)
971 {
972         struct nfs_open_context *ctx = nfs_file_open_context(filp);
973 
974         if (ctx) {
975                 struct inode *inode = d_inode(ctx->dentry);
976 
977                 /*
978                  * We fatal error on write before. Try to writeback
979                  * every page again.
980                  */
981                 if (ctx->error < 0)
982                         invalidate_inode_pages2(inode->i_mapping);
983                 filp->private_data = NULL;
984                 spin_lock(&inode->i_lock);
985                 list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
986                 spin_unlock(&inode->i_lock);
987                 put_nfs_open_context_sync(ctx);
988         }
989 }
990 
991 /*
992  * These allocate and release file read/write context information.
993  */
994 int nfs_open(struct inode *inode, struct file *filp)
995 {
996         struct nfs_open_context *ctx;
997 
998         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
999         if (IS_ERR(ctx))
1000                 return PTR_ERR(ctx);
1001         nfs_file_set_open_context(filp, ctx);
1002         put_nfs_open_context(ctx);
1003         nfs_fscache_open_file(inode, filp);
1004         return 0;
1005 }
1006 
1007 /*
1008  * This function is called whenever some part of NFS notices that
1009  * the cached attributes have to be refreshed.
1010  */
1011 int
1012 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1013 {
1014         int              status = -ESTALE;
1015         struct nfs4_label *label = NULL;
1016         struct nfs_fattr *fattr = NULL;
1017         struct nfs_inode *nfsi = NFS_I(inode);
1018 
1019         dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1020                 inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1021 
1022         trace_nfs_revalidate_inode_enter(inode);
1023 
1024         if (is_bad_inode(inode))
1025                 goto out;
1026         if (NFS_STALE(inode))
1027                 goto out;
1028 
1029         /* pNFS: Attributes aren't updated until we layoutcommit */
1030         if (S_ISREG(inode->i_mode)) {
1031                 status = pnfs_sync_inode(inode, false);
1032                 if (status)
1033                         goto out;
1034         }
1035 
1036         status = -ENOMEM;
1037         fattr = nfs_alloc_fattr();
1038         if (fattr == NULL)
1039                 goto out;
1040 
1041         nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1042 
1043         label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1044         if (IS_ERR(label)) {
1045                 status = PTR_ERR(label);
1046                 goto out;
1047         }
1048 
1049         status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, label);
1050         if (status != 0) {
1051                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1052                          inode->i_sb->s_id,
1053                          (unsigned long long)NFS_FILEID(inode), status);
1054                 if (status == -ESTALE) {
1055                         nfs_zap_caches(inode);
1056                         if (!S_ISDIR(inode->i_mode))
1057                                 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1058                 }
1059                 goto err_out;
1060         }
1061 
1062         status = nfs_refresh_inode(inode, fattr);
1063         if (status) {
1064                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1065                          inode->i_sb->s_id,
1066                          (unsigned long long)NFS_FILEID(inode), status);
1067                 goto err_out;
1068         }
1069 
1070         if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1071                 nfs_zap_acl_cache(inode);
1072 
1073         nfs_setsecurity(inode, fattr, label);
1074 
1075         dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1076                 inode->i_sb->s_id,
1077                 (unsigned long long)NFS_FILEID(inode));
1078 
1079 err_out:
1080         nfs4_label_free(label);
1081 out:
1082         nfs_free_fattr(fattr);
1083         trace_nfs_revalidate_inode_exit(inode, status);
1084         return status;
1085 }
1086 
1087 int nfs_attribute_cache_expired(struct inode *inode)
1088 {
1089         if (nfs_have_delegated_attributes(inode))
1090                 return 0;
1091         return nfs_attribute_timeout(inode);
1092 }
1093 
1094 /**
1095  * nfs_revalidate_inode - Revalidate the inode attributes
1096  * @server - pointer to nfs_server struct
1097  * @inode - pointer to inode struct
1098  *
1099  * Updates inode attribute information by retrieving the data from the server.
1100  */
1101 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1102 {
1103         if (!nfs_need_revalidate_inode(inode))
1104                 return NFS_STALE(inode) ? -ESTALE : 0;
1105         return __nfs_revalidate_inode(server, inode);
1106 }
1107 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1108 
1109 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1110 {
1111         struct nfs_inode *nfsi = NFS_I(inode);
1112         int ret;
1113 
1114         if (mapping->nrpages != 0) {
1115                 if (S_ISREG(inode->i_mode)) {
1116                         unmap_mapping_range(mapping, 0, 0, 0);
1117                         ret = nfs_sync_mapping(mapping);
1118                         if (ret < 0)
1119                                 return ret;
1120                 }
1121                 ret = invalidate_inode_pages2(mapping);
1122                 if (ret < 0)
1123                         return ret;
1124         }
1125         if (S_ISDIR(inode->i_mode)) {
1126                 spin_lock(&inode->i_lock);
1127                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1128                 spin_unlock(&inode->i_lock);
1129         }
1130         nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1131         nfs_fscache_wait_on_invalidate(inode);
1132 
1133         dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1134                         inode->i_sb->s_id,
1135                         (unsigned long long)NFS_FILEID(inode));
1136         return 0;
1137 }
1138 
1139 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1140 {
1141         return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1142                 NFS_STALE(inode);
1143 }
1144 
1145 int nfs_revalidate_mapping_rcu(struct inode *inode)
1146 {
1147         struct nfs_inode *nfsi = NFS_I(inode);
1148         unsigned long *bitlock = &nfsi->flags;
1149         int ret = 0;
1150 
1151         if (IS_SWAPFILE(inode))
1152                 goto out;
1153         if (nfs_mapping_need_revalidate_inode(inode)) {
1154                 ret = -ECHILD;
1155                 goto out;
1156         }
1157         spin_lock(&inode->i_lock);
1158         if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1159             (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1160                 ret = -ECHILD;
1161         spin_unlock(&inode->i_lock);
1162 out:
1163         return ret;
1164 }
1165 
1166 /**
1167  * nfs_revalidate_mapping - Revalidate the pagecache
1168  * @inode - pointer to host inode
1169  * @mapping - pointer to mapping
1170  */
1171 int nfs_revalidate_mapping(struct inode *inode,
1172                 struct address_space *mapping)
1173 {
1174         struct nfs_inode *nfsi = NFS_I(inode);
1175         unsigned long *bitlock = &nfsi->flags;
1176         int ret = 0;
1177 
1178         /* swapfiles are not supposed to be shared. */
1179         if (IS_SWAPFILE(inode))
1180                 goto out;
1181 
1182         if (nfs_mapping_need_revalidate_inode(inode)) {
1183                 ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1184                 if (ret < 0)
1185                         goto out;
1186         }
1187 
1188         /*
1189          * We must clear NFS_INO_INVALID_DATA first to ensure that
1190          * invalidations that come in while we're shooting down the mappings
1191          * are respected. But, that leaves a race window where one revalidator
1192          * can clear the flag, and then another checks it before the mapping
1193          * gets invalidated. Fix that by serializing access to this part of
1194          * the function.
1195          *
1196          * At the same time, we need to allow other tasks to see whether we
1197          * might be in the middle of invalidating the pages, so we only set
1198          * the bit lock here if it looks like we're going to be doing that.
1199          */
1200         for (;;) {
1201                 ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1202                                          nfs_wait_bit_killable, TASK_KILLABLE);
1203                 if (ret)
1204                         goto out;
1205                 spin_lock(&inode->i_lock);
1206                 if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1207                         spin_unlock(&inode->i_lock);
1208                         continue;
1209                 }
1210                 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1211                         break;
1212                 spin_unlock(&inode->i_lock);
1213                 goto out;
1214         }
1215 
1216         set_bit(NFS_INO_INVALIDATING, bitlock);
1217         smp_wmb();
1218         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1219         spin_unlock(&inode->i_lock);
1220         trace_nfs_invalidate_mapping_enter(inode);
1221         ret = nfs_invalidate_mapping(inode, mapping);
1222         trace_nfs_invalidate_mapping_exit(inode, ret);
1223 
1224         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1225         smp_mb__after_atomic();
1226         wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1227 out:
1228         return ret;
1229 }
1230 
1231 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1232 {
1233         struct inode *inode = &nfsi->vfs_inode;
1234 
1235         assert_spin_locked(&inode->i_lock);
1236 
1237         if (!S_ISREG(inode->i_mode))
1238                 return false;
1239         if (list_empty(&nfsi->open_files))
1240                 return false;
1241         /* Note: This relies on nfsi->open_files being ordered with writers
1242          *       being placed at the head of the list.
1243          *       See nfs_inode_attach_open_context()
1244          */
1245         return (list_first_entry(&nfsi->open_files,
1246                         struct nfs_open_context,
1247                         list)->mode & FMODE_WRITE) == FMODE_WRITE;
1248 }
1249 
1250 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1251 {
1252         return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1253 }
1254 
1255 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1256 {
1257         struct nfs_inode *nfsi = NFS_I(inode);
1258         unsigned long ret = 0;
1259 
1260         if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1261                         && (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1262                         && inode->i_version == fattr->pre_change_attr) {
1263                 inode->i_version = fattr->change_attr;
1264                 if (S_ISDIR(inode->i_mode))
1265                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1266                 ret |= NFS_INO_INVALID_ATTR;
1267         }
1268         /* If we have atomic WCC data, we may update some attributes */
1269         if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1270                         && (fattr->valid & NFS_ATTR_FATTR_CTIME)
1271                         && timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1272                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1273                 ret |= NFS_INO_INVALID_ATTR;
1274         }
1275 
1276         if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1277                         && (fattr->valid & NFS_ATTR_FATTR_MTIME)
1278                         && timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1279                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1280                 if (S_ISDIR(inode->i_mode))
1281                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1282                 ret |= NFS_INO_INVALID_ATTR;
1283         }
1284         if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1285                         && (fattr->valid & NFS_ATTR_FATTR_SIZE)
1286                         && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1287                         && nfsi->nrequests == 0) {
1288                 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1289                 ret |= NFS_INO_INVALID_ATTR;
1290         }
1291 
1292         return ret;
1293 }
1294 
1295 /**
1296  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1297  * @inode - pointer to inode
1298  * @fattr - updated attributes
1299  *
1300  * Verifies the attribute cache. If we have just changed the attributes,
1301  * so that fattr carries weak cache consistency data, then it may
1302  * also update the ctime/mtime/change_attribute.
1303  */
1304 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1305 {
1306         struct nfs_inode *nfsi = NFS_I(inode);
1307         loff_t cur_size, new_isize;
1308         unsigned long invalid = 0;
1309 
1310 
1311         if (nfs_have_delegated_attributes(inode))
1312                 return 0;
1313         /* Has the inode gone and changed behind our back? */
1314         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1315                 return -EIO;
1316         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1317                 return -EIO;
1318 
1319         if (!nfs_file_has_buffered_writers(nfsi)) {
1320                 /* Verify a few of the more important attributes */
1321                 if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && inode->i_version != fattr->change_attr)
1322                         invalid |= NFS_INO_INVALID_ATTR | NFS_INO_REVAL_PAGECACHE;
1323 
1324                 if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1325                         invalid |= NFS_INO_INVALID_ATTR;
1326 
1327                 if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
1328                         invalid |= NFS_INO_INVALID_ATTR;
1329 
1330                 if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1331                         cur_size = i_size_read(inode);
1332                         new_isize = nfs_size_to_loff_t(fattr->size);
1333                         if (cur_size != new_isize)
1334                                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1335                 }
1336         }
1337 
1338         /* Have any file permissions changed? */
1339         if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1340                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1341         if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1342                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1343         if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1344                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1345 
1346         /* Has the link count changed? */
1347         if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1348                 invalid |= NFS_INO_INVALID_ATTR;
1349 
1350         if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1351                 invalid |= NFS_INO_INVALID_ATIME;
1352 
1353         if (invalid != 0)
1354                 nfs_set_cache_invalid(inode, invalid | NFS_INO_REVAL_FORCED);
1355 
1356         nfsi->read_cache_jiffies = fattr->time_start;
1357         return 0;
1358 }
1359 
1360 static atomic_long_t nfs_attr_generation_counter;
1361 
1362 static unsigned long nfs_read_attr_generation_counter(void)
1363 {
1364         return atomic_long_read(&nfs_attr_generation_counter);
1365 }
1366 
1367 unsigned long nfs_inc_attr_generation_counter(void)
1368 {
1369         return atomic_long_inc_return(&nfs_attr_generation_counter);
1370 }
1371 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1372 
1373 void nfs_fattr_init(struct nfs_fattr *fattr)
1374 {
1375         fattr->valid = 0;
1376         fattr->time_start = jiffies;
1377         fattr->gencount = nfs_inc_attr_generation_counter();
1378         fattr->owner_name = NULL;
1379         fattr->group_name = NULL;
1380 }
1381 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1382 
1383 /**
1384  * nfs_fattr_set_barrier
1385  * @fattr: attributes
1386  *
1387  * Used to set a barrier after an attribute was updated. This
1388  * barrier ensures that older attributes from RPC calls that may
1389  * have raced with our update cannot clobber these new values.
1390  * Note that you are still responsible for ensuring that other
1391  * operations which change the attribute on the server do not
1392  * collide.
1393  */
1394 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1395 {
1396         fattr->gencount = nfs_inc_attr_generation_counter();
1397 }
1398 
1399 struct nfs_fattr *nfs_alloc_fattr(void)
1400 {
1401         struct nfs_fattr *fattr;
1402 
1403         fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1404         if (fattr != NULL)
1405                 nfs_fattr_init(fattr);
1406         return fattr;
1407 }
1408 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1409 
1410 struct nfs_fh *nfs_alloc_fhandle(void)
1411 {
1412         struct nfs_fh *fh;
1413 
1414         fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1415         if (fh != NULL)
1416                 fh->size = 0;
1417         return fh;
1418 }
1419 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1420 
1421 #ifdef NFS_DEBUG
1422 /*
1423  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1424  *                             in the same way that wireshark does
1425  *
1426  * @fh: file handle
1427  *
1428  * For debugging only.
1429  */
1430 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1431 {
1432         /* wireshark uses 32-bit AUTODIN crc and does a bitwise
1433          * not on the result */
1434         return nfs_fhandle_hash(fh);
1435 }
1436 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1437 
1438 /*
1439  * _nfs_display_fhandle - display an NFS file handle on the console
1440  *
1441  * @fh: file handle to display
1442  * @caption: display caption
1443  *
1444  * For debugging only.
1445  */
1446 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1447 {
1448         unsigned short i;
1449 
1450         if (fh == NULL || fh->size == 0) {
1451                 printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1452                 return;
1453         }
1454 
1455         printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1456                caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1457         for (i = 0; i < fh->size; i += 16) {
1458                 __be32 *pos = (__be32 *)&fh->data[i];
1459 
1460                 switch ((fh->size - i - 1) >> 2) {
1461                 case 0:
1462                         printk(KERN_DEFAULT " %08x\n",
1463                                 be32_to_cpup(pos));
1464                         break;
1465                 case 1:
1466                         printk(KERN_DEFAULT " %08x %08x\n",
1467                                 be32_to_cpup(pos), be32_to_cpup(pos + 1));
1468                         break;
1469                 case 2:
1470                         printk(KERN_DEFAULT " %08x %08x %08x\n",
1471                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1472                                 be32_to_cpup(pos + 2));
1473                         break;
1474                 default:
1475                         printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1476                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1477                                 be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1478                 }
1479         }
1480 }
1481 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1482 #endif
1483 
1484 /**
1485  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1486  * @inode - pointer to inode
1487  * @fattr - attributes
1488  *
1489  * Attempt to divine whether or not an RPC call reply carrying stale
1490  * attributes got scheduled after another call carrying updated ones.
1491  *
1492  * To do so, the function first assumes that a more recent ctime means
1493  * that the attributes in fattr are newer, however it also attempt to
1494  * catch the case where ctime either didn't change, or went backwards
1495  * (if someone reset the clock on the server) by looking at whether
1496  * or not this RPC call was started after the inode was last updated.
1497  * Note also the check for wraparound of 'attr_gencount'
1498  *
1499  * The function returns 'true' if it thinks the attributes in 'fattr' are
1500  * more recent than the ones cached in the inode.
1501  *
1502  */
1503 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1504 {
1505         const struct nfs_inode *nfsi = NFS_I(inode);
1506 
1507         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1508                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1509 }
1510 
1511 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1512 {
1513         int ret;
1514 
1515         trace_nfs_refresh_inode_enter(inode);
1516 
1517         if (nfs_inode_attrs_need_update(inode, fattr))
1518                 ret = nfs_update_inode(inode, fattr);
1519         else
1520                 ret = nfs_check_inode_attributes(inode, fattr);
1521 
1522         trace_nfs_refresh_inode_exit(inode, ret);
1523         return ret;
1524 }
1525 
1526 /**
1527  * nfs_refresh_inode - try to update the inode attribute cache
1528  * @inode - pointer to inode
1529  * @fattr - updated attributes
1530  *
1531  * Check that an RPC call that returned attributes has not overlapped with
1532  * other recent updates of the inode metadata, then decide whether it is
1533  * safe to do a full update of the inode attributes, or whether just to
1534  * call nfs_check_inode_attributes.
1535  */
1536 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1537 {
1538         int status;
1539 
1540         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1541                 return 0;
1542         spin_lock(&inode->i_lock);
1543         status = nfs_refresh_inode_locked(inode, fattr);
1544         spin_unlock(&inode->i_lock);
1545 
1546         return status;
1547 }
1548 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1549 
1550 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1551 {
1552         unsigned long invalid = NFS_INO_INVALID_ATTR;
1553 
1554         if (S_ISDIR(inode->i_mode))
1555                 invalid |= NFS_INO_INVALID_DATA;
1556         nfs_set_cache_invalid(inode, invalid);
1557         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1558                 return 0;
1559         return nfs_refresh_inode_locked(inode, fattr);
1560 }
1561 
1562 /**
1563  * nfs_post_op_update_inode - try to update the inode attribute cache
1564  * @inode - pointer to inode
1565  * @fattr - updated attributes
1566  *
1567  * After an operation that has changed the inode metadata, mark the
1568  * attribute cache as being invalid, then try to update it.
1569  *
1570  * NB: if the server didn't return any post op attributes, this
1571  * function will force the retrieval of attributes before the next
1572  * NFS request.  Thus it should be used only for operations that
1573  * are expected to change one or more attributes, to avoid
1574  * unnecessary NFS requests and trips through nfs_update_inode().
1575  */
1576 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1577 {
1578         int status;
1579 
1580         spin_lock(&inode->i_lock);
1581         nfs_fattr_set_barrier(fattr);
1582         status = nfs_post_op_update_inode_locked(inode, fattr);
1583         spin_unlock(&inode->i_lock);
1584 
1585         return status;
1586 }
1587 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1588 
1589 /**
1590  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1591  * @inode - pointer to inode
1592  * @fattr - updated attributes
1593  *
1594  * After an operation that has changed the inode metadata, mark the
1595  * attribute cache as being invalid, then try to update it. Fake up
1596  * weak cache consistency data, if none exist.
1597  *
1598  * This function is mainly designed to be used by the ->write_done() functions.
1599  */
1600 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1601 {
1602         int status;
1603 
1604         /* Don't do a WCC update if these attributes are already stale */
1605         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1606                         !nfs_inode_attrs_need_update(inode, fattr)) {
1607                 fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1608                                 | NFS_ATTR_FATTR_PRESIZE
1609                                 | NFS_ATTR_FATTR_PREMTIME
1610                                 | NFS_ATTR_FATTR_PRECTIME);
1611                 goto out_noforce;
1612         }
1613         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1614                         (fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1615                 fattr->pre_change_attr = inode->i_version;
1616                 fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1617         }
1618         if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1619                         (fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1620                 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1621                 fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1622         }
1623         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1624                         (fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1625                 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1626                 fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1627         }
1628         if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1629                         (fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1630                 fattr->pre_size = i_size_read(inode);
1631                 fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1632         }
1633 out_noforce:
1634         status = nfs_post_op_update_inode_locked(inode, fattr);
1635         return status;
1636 }
1637 
1638 /**
1639  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1640  * @inode - pointer to inode
1641  * @fattr - updated attributes
1642  *
1643  * After an operation that has changed the inode metadata, mark the
1644  * attribute cache as being invalid, then try to update it. Fake up
1645  * weak cache consistency data, if none exist.
1646  *
1647  * This function is mainly designed to be used by the ->write_done() functions.
1648  */
1649 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1650 {
1651         int status;
1652 
1653         spin_lock(&inode->i_lock);
1654         nfs_fattr_set_barrier(fattr);
1655         status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1656         spin_unlock(&inode->i_lock);
1657         return status;
1658 }
1659 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1660 
1661 
1662 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1663                                     struct nfs_fattr *fattr)
1664 {
1665         bool ret1 = true, ret2 = true;
1666 
1667         if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1668                 ret1 = (nfsi->fileid == fattr->fileid);
1669         if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1670                 ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1671         return ret1 || ret2;
1672 }
1673 
1674 /*
1675  * Many nfs protocol calls return the new file attributes after
1676  * an operation.  Here we update the inode to reflect the state
1677  * of the server's inode.
1678  *
1679  * This is a bit tricky because we have to make sure all dirty pages
1680  * have been sent off to the server before calling invalidate_inode_pages.
1681  * To make sure no other process adds more write requests while we try
1682  * our best to flush them, we make them sleep during the attribute refresh.
1683  *
1684  * A very similar scenario holds for the dir cache.
1685  */
1686 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1687 {
1688         struct nfs_server *server;
1689         struct nfs_inode *nfsi = NFS_I(inode);
1690         loff_t cur_isize, new_isize;
1691         unsigned long invalid = 0;
1692         unsigned long now = jiffies;
1693         unsigned long save_cache_validity;
1694         bool have_writers = nfs_file_has_buffered_writers(nfsi);
1695         bool cache_revalidated = true;
1696 
1697         dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1698                         __func__, inode->i_sb->s_id, inode->i_ino,
1699                         nfs_display_fhandle_hash(NFS_FH(inode)),
1700                         atomic_read(&inode->i_count), fattr->valid);
1701 
1702         if (!nfs_fileid_valid(nfsi, fattr)) {
1703                 printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1704                         "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1705                         NFS_SERVER(inode)->nfs_client->cl_hostname,
1706                         inode->i_sb->s_id, (long long)nfsi->fileid,
1707                         (long long)fattr->fileid);
1708                 goto out_err;
1709         }
1710 
1711         /*
1712          * Make sure the inode's type hasn't changed.
1713          */
1714         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1715                 /*
1716                 * Big trouble! The inode has become a different object.
1717                 */
1718                 printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1719                                 __func__, inode->i_ino, inode->i_mode, fattr->mode);
1720                 goto out_err;
1721         }
1722 
1723         server = NFS_SERVER(inode);
1724         /* Update the fsid? */
1725         if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1726                         !nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1727                         !IS_AUTOMOUNT(inode))
1728                 server->fsid = fattr->fsid;
1729 
1730         /*
1731          * Update the read time so we don't revalidate too often.
1732          */
1733         nfsi->read_cache_jiffies = fattr->time_start;
1734 
1735         save_cache_validity = nfsi->cache_validity;
1736         nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1737                         | NFS_INO_INVALID_ATIME
1738                         | NFS_INO_REVAL_FORCED
1739                         | NFS_INO_REVAL_PAGECACHE);
1740 
1741         /* Do atomic weak cache consistency updates */
1742         invalid |= nfs_wcc_update_inode(inode, fattr);
1743 
1744         if (pnfs_layoutcommit_outstanding(inode)) {
1745                 nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1746                 cache_revalidated = false;
1747         }
1748 
1749         /* More cache consistency checks */
1750         if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1751                 if (inode->i_version != fattr->change_attr) {
1752                         dprintk("NFS: change_attr change on server for file %s/%ld\n",
1753                                         inode->i_sb->s_id, inode->i_ino);
1754                         /* Could it be a race with writeback? */
1755                         if (!have_writers) {
1756                                 invalid |= NFS_INO_INVALID_ATTR
1757                                         | NFS_INO_INVALID_DATA
1758                                         | NFS_INO_INVALID_ACCESS
1759                                         | NFS_INO_INVALID_ACL;
1760                                 if (S_ISDIR(inode->i_mode))
1761                                         nfs_force_lookup_revalidate(inode);
1762                         }
1763                         inode->i_version = fattr->change_attr;
1764                 }
1765         } else {
1766                 nfsi->cache_validity |= save_cache_validity;
1767                 cache_revalidated = false;
1768         }
1769 
1770         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1771                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1772         } else if (server->caps & NFS_CAP_MTIME) {
1773                 nfsi->cache_validity |= save_cache_validity &
1774                                 (NFS_INO_INVALID_ATTR
1775                                 | NFS_INO_REVAL_FORCED);
1776                 cache_revalidated = false;
1777         }
1778 
1779         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1780                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1781         } else if (server->caps & NFS_CAP_CTIME) {
1782                 nfsi->cache_validity |= save_cache_validity &
1783                                 (NFS_INO_INVALID_ATTR
1784                                 | NFS_INO_REVAL_FORCED);
1785                 cache_revalidated = false;
1786         }
1787 
1788         /* Check if our cached file size is stale */
1789         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1790                 new_isize = nfs_size_to_loff_t(fattr->size);
1791                 cur_isize = i_size_read(inode);
1792                 if (new_isize != cur_isize) {
1793                         /* Do we perhaps have any outstanding writes, or has
1794                          * the file grown beyond our last write? */
1795                         if (nfsi->nrequests == 0 || new_isize > cur_isize) {
1796                                 i_size_write(inode, new_isize);
1797                                 if (!have_writers)
1798                                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1799                         }
1800                         dprintk("NFS: isize change on server for file %s/%ld "
1801                                         "(%Ld to %Ld)\n",
1802                                         inode->i_sb->s_id,
1803                                         inode->i_ino,
1804                                         (long long)cur_isize,
1805                                         (long long)new_isize);
1806                 }
1807         } else {
1808                 nfsi->cache_validity |= save_cache_validity &
1809                                 (NFS_INO_INVALID_ATTR
1810                                 | NFS_INO_REVAL_PAGECACHE
1811                                 | NFS_INO_REVAL_FORCED);
1812                 cache_revalidated = false;
1813         }
1814 
1815 
1816         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1817                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1818         else if (server->caps & NFS_CAP_ATIME) {
1819                 nfsi->cache_validity |= save_cache_validity &
1820                                 (NFS_INO_INVALID_ATIME
1821                                 | NFS_INO_REVAL_FORCED);
1822                 cache_revalidated = false;
1823         }
1824 
1825         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1826                 if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1827                         umode_t newmode = inode->i_mode & S_IFMT;
1828                         newmode |= fattr->mode & S_IALLUGO;
1829                         inode->i_mode = newmode;
1830                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1831                 }
1832         } else if (server->caps & NFS_CAP_MODE) {
1833                 nfsi->cache_validity |= save_cache_validity &
1834                                 (NFS_INO_INVALID_ATTR
1835                                 | NFS_INO_INVALID_ACCESS
1836                                 | NFS_INO_INVALID_ACL
1837                                 | NFS_INO_REVAL_FORCED);
1838                 cache_revalidated = false;
1839         }
1840 
1841         if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1842                 if (!uid_eq(inode->i_uid, fattr->uid)) {
1843                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1844                         inode->i_uid = fattr->uid;
1845                 }
1846         } else if (server->caps & NFS_CAP_OWNER) {
1847                 nfsi->cache_validity |= save_cache_validity &
1848                                 (NFS_INO_INVALID_ATTR
1849                                 | NFS_INO_INVALID_ACCESS
1850                                 | NFS_INO_INVALID_ACL
1851                                 | NFS_INO_REVAL_FORCED);
1852                 cache_revalidated = false;
1853         }
1854 
1855         if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1856                 if (!gid_eq(inode->i_gid, fattr->gid)) {
1857                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1858                         inode->i_gid = fattr->gid;
1859                 }
1860         } else if (server->caps & NFS_CAP_OWNER_GROUP) {
1861                 nfsi->cache_validity |= save_cache_validity &
1862                                 (NFS_INO_INVALID_ATTR
1863                                 | NFS_INO_INVALID_ACCESS
1864                                 | NFS_INO_INVALID_ACL
1865                                 | NFS_INO_REVAL_FORCED);
1866                 cache_revalidated = false;
1867         }
1868 
1869         if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1870                 if (inode->i_nlink != fattr->nlink) {
1871                         invalid |= NFS_INO_INVALID_ATTR;
1872                         if (S_ISDIR(inode->i_mode))
1873                                 invalid |= NFS_INO_INVALID_DATA;
1874                         set_nlink(inode, fattr->nlink);
1875                 }
1876         } else if (server->caps & NFS_CAP_NLINK) {
1877                 nfsi->cache_validity |= save_cache_validity &
1878                                 (NFS_INO_INVALID_ATTR
1879                                 | NFS_INO_REVAL_FORCED);
1880                 cache_revalidated = false;
1881         }
1882 
1883         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1884                 /*
1885                  * report the blocks in 512byte units
1886                  */
1887                 inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1888         } else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1889                 inode->i_blocks = fattr->du.nfs2.blocks;
1890         else
1891                 cache_revalidated = false;
1892 
1893         /* Update attrtimeo value if we're out of the unstable period */
1894         if (invalid & NFS_INO_INVALID_ATTR) {
1895                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1896                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1897                 nfsi->attrtimeo_timestamp = now;
1898                 /* Set barrier to be more recent than all outstanding updates */
1899                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1900         } else {
1901                 if (cache_revalidated) {
1902                         if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
1903                                 nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1904                                 nfsi->attrtimeo <<= 1;
1905                                 if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
1906                                         nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1907                         }
1908                         nfsi->attrtimeo_timestamp = now;
1909                 }
1910                 /* Set the barrier to be more recent than this fattr */
1911                 if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
1912                         nfsi->attr_gencount = fattr->gencount;
1913         }
1914 
1915         /* Don't declare attrcache up to date if there were no attrs! */
1916         if (cache_revalidated)
1917                 invalid &= ~NFS_INO_INVALID_ATTR;
1918 
1919         /* Don't invalidate the data if we were to blame */
1920         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1921                                 || S_ISLNK(inode->i_mode)))
1922                 invalid &= ~NFS_INO_INVALID_DATA;
1923         if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1924                         (save_cache_validity & NFS_INO_REVAL_FORCED))
1925                 nfs_set_cache_invalid(inode, invalid);
1926 
1927         return 0;
1928  out_err:
1929         /*
1930          * No need to worry about unhashing the dentry, as the
1931          * lookup validation will know that the inode is bad.
1932          * (But we fall through to invalidate the caches.)
1933          */
1934         nfs_invalidate_inode(inode);
1935         return -ESTALE;
1936 }
1937 
1938 struct inode *nfs_alloc_inode(struct super_block *sb)
1939 {
1940         struct nfs_inode *nfsi;
1941         nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1942         if (!nfsi)
1943                 return NULL;
1944         nfsi->flags = 0UL;
1945         nfsi->cache_validity = 0UL;
1946 #if IS_ENABLED(CONFIG_NFS_V4)
1947         nfsi->nfs4_acl = NULL;
1948 #endif /* CONFIG_NFS_V4 */
1949         return &nfsi->vfs_inode;
1950 }
1951 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1952 
1953 static void nfs_i_callback(struct rcu_head *head)
1954 {
1955         struct inode *inode = container_of(head, struct inode, i_rcu);
1956         kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1957 }
1958 
1959 void nfs_destroy_inode(struct inode *inode)
1960 {
1961         call_rcu(&inode->i_rcu, nfs_i_callback);
1962 }
1963 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1964 
1965 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1966 {
1967 #if IS_ENABLED(CONFIG_NFS_V4)
1968         INIT_LIST_HEAD(&nfsi->open_states);
1969         nfsi->delegation = NULL;
1970         init_rwsem(&nfsi->rwsem);
1971         nfsi->layout = NULL;
1972 #endif
1973 }
1974 
1975 static void init_once(void *foo)
1976 {
1977         struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1978 
1979         inode_init_once(&nfsi->vfs_inode);
1980         INIT_LIST_HEAD(&nfsi->open_files);
1981         INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1982         INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1983         INIT_LIST_HEAD(&nfsi->commit_info.list);
1984         nfsi->nrequests = 0;
1985         nfsi->commit_info.ncommit = 0;
1986         atomic_set(&nfsi->commit_info.rpcs_out, 0);
1987         init_rwsem(&nfsi->rmdir_sem);
1988         nfs4_init_once(nfsi);
1989 }
1990 
1991 static int __init nfs_init_inodecache(void)
1992 {
1993         nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1994                                              sizeof(struct nfs_inode),
1995                                              0, (SLAB_RECLAIM_ACCOUNT|
1996                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1997                                              init_once);
1998         if (nfs_inode_cachep == NULL)
1999                 return -ENOMEM;
2000 
2001         return 0;
2002 }
2003 
2004 static void nfs_destroy_inodecache(void)
2005 {
2006         /*
2007          * Make sure all delayed rcu free inodes are flushed before we
2008          * destroy cache.
2009          */
2010         rcu_barrier();
2011         kmem_cache_destroy(nfs_inode_cachep);
2012 }
2013 
2014 struct workqueue_struct *nfsiod_workqueue;
2015 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2016 
2017 /*
2018  * start up the nfsiod workqueue
2019  */
2020 static int nfsiod_start(void)
2021 {
2022         struct workqueue_struct *wq;
2023         dprintk("RPC:       creating workqueue nfsiod\n");
2024         wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2025         if (wq == NULL)
2026                 return -ENOMEM;
2027         nfsiod_workqueue = wq;
2028         return 0;
2029 }
2030 
2031 /*
2032  * Destroy the nfsiod workqueue
2033  */
2034 static void nfsiod_stop(void)
2035 {
2036         struct workqueue_struct *wq;
2037 
2038         wq = nfsiod_workqueue;
2039         if (wq == NULL)
2040                 return;
2041         nfsiod_workqueue = NULL;
2042         destroy_workqueue(wq);
2043 }
2044 
2045 unsigned int nfs_net_id;
2046 EXPORT_SYMBOL_GPL(nfs_net_id);
2047 
2048 static int nfs_net_init(struct net *net)
2049 {
2050         nfs_clients_init(net);
2051         return nfs_fs_proc_net_init(net);
2052 }
2053 
2054 static void nfs_net_exit(struct net *net)
2055 {
2056         nfs_fs_proc_net_exit(net);
2057         nfs_cleanup_cb_ident_idr(net);
2058 }
2059 
2060 static struct pernet_operations nfs_net_ops = {
2061         .init = nfs_net_init,
2062         .exit = nfs_net_exit,
2063         .id   = &nfs_net_id,
2064         .size = sizeof(struct nfs_net),
2065 };
2066 
2067 /*
2068  * Initialize NFS
2069  */
2070 static int __init init_nfs_fs(void)
2071 {
2072         int err;
2073 
2074         err = register_pernet_subsys(&nfs_net_ops);
2075         if (err < 0)
2076                 goto out9;
2077 
2078         err = nfs_fscache_register();
2079         if (err < 0)
2080                 goto out8;
2081 
2082         err = nfsiod_start();
2083         if (err)
2084                 goto out7;
2085 
2086         err = nfs_fs_proc_init();
2087         if (err)
2088                 goto out6;
2089 
2090         err = nfs_init_nfspagecache();
2091         if (err)
2092                 goto out5;
2093 
2094         err = nfs_init_inodecache();
2095         if (err)
2096                 goto out4;
2097 
2098         err = nfs_init_readpagecache();
2099         if (err)
2100                 goto out3;
2101 
2102         err = nfs_init_writepagecache();
2103         if (err)
2104                 goto out2;
2105 
2106         err = nfs_init_directcache();
2107         if (err)
2108                 goto out1;
2109 
2110         rpc_proc_register(&init_net, &nfs_rpcstat);
2111 
2112         err = register_nfs_fs();
2113         if (err)
2114                 goto out0;
2115 
2116         return 0;
2117 out0:
2118         rpc_proc_unregister(&init_net, "nfs");
2119         nfs_destroy_directcache();
2120 out1:
2121         nfs_destroy_writepagecache();
2122 out2:
2123         nfs_destroy_readpagecache();
2124 out3:
2125         nfs_destroy_inodecache();
2126 out4:
2127         nfs_destroy_nfspagecache();
2128 out5:
2129         nfs_fs_proc_exit();
2130 out6:
2131         nfsiod_stop();
2132 out7:
2133         nfs_fscache_unregister();
2134 out8:
2135         unregister_pernet_subsys(&nfs_net_ops);
2136 out9:
2137         return err;
2138 }
2139 
2140 static void __exit exit_nfs_fs(void)
2141 {
2142         nfs_destroy_directcache();
2143         nfs_destroy_writepagecache();
2144         nfs_destroy_readpagecache();
2145         nfs_destroy_inodecache();
2146         nfs_destroy_nfspagecache();
2147         nfs_fscache_unregister();
2148         unregister_pernet_subsys(&nfs_net_ops);
2149         rpc_proc_unregister(&init_net, "nfs");
2150         unregister_nfs_fs();
2151         nfs_fs_proc_exit();
2152         nfsiod_stop();
2153 }
2154 
2155 /* Not quite true; I just maintain it */
2156 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2157 MODULE_LICENSE("GPL");
2158 module_param(enable_ino64, bool, 0644);
2159 
2160 module_init(init_nfs_fs)
2161 module_exit(exit_nfs_fs)
2162 

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