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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, unsigned int mode)
 89 {
 90         return nfs_wait_killable(mode);
 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 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
390 struct inode *
391 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
392 {
393         struct nfs_find_desc desc = {
394                 .fh     = fh,
395                 .fattr  = fattr,
396         };
397         struct inode *inode;
398         unsigned long hash;
399 
400         if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
401             !(fattr->valid & NFS_ATTR_FATTR_TYPE))
402                 return NULL;
403 
404         hash = nfs_fattr_to_ino_t(fattr);
405         inode = ilookup5(sb, hash, nfs_find_actor, &desc);
406 
407         dprintk("%s: returning %p\n", __func__, inode);
408         return inode;
409 }
410 
411 /*
412  * This is our front-end to iget that looks up inodes by file handle
413  * instead of inode number.
414  */
415 struct inode *
416 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
417 {
418         struct nfs_find_desc desc = {
419                 .fh     = fh,
420                 .fattr  = fattr
421         };
422         struct inode *inode = ERR_PTR(-ENOENT);
423         unsigned long hash;
424 
425         nfs_attr_check_mountpoint(sb, fattr);
426 
427         if (nfs_attr_use_mounted_on_fileid(fattr))
428                 fattr->fileid = fattr->mounted_on_fileid;
429         else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
430                 goto out_no_inode;
431         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
432                 goto out_no_inode;
433 
434         hash = nfs_fattr_to_ino_t(fattr);
435 
436         inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
437         if (inode == NULL) {
438                 inode = ERR_PTR(-ENOMEM);
439                 goto out_no_inode;
440         }
441 
442         if (inode->i_state & I_NEW) {
443                 struct nfs_inode *nfsi = NFS_I(inode);
444                 unsigned long now = jiffies;
445 
446                 /* We set i_ino for the few things that still rely on it,
447                  * such as stat(2) */
448                 inode->i_ino = hash;
449 
450                 /* We can't support update_atime(), since the server will reset it */
451                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
452                 inode->i_mode = fattr->mode;
453                 if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
454                                 && nfs_server_capable(inode, NFS_CAP_MODE))
455                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
456                 /* Why so? Because we want revalidate for devices/FIFOs, and
457                  * that's precisely what we have in nfs_file_inode_operations.
458                  */
459                 inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
460                 if (S_ISREG(inode->i_mode)) {
461                         inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
462                         inode->i_data.a_ops = &nfs_file_aops;
463                 } else if (S_ISDIR(inode->i_mode)) {
464                         inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
465                         inode->i_fop = &nfs_dir_operations;
466                         inode->i_data.a_ops = &nfs_dir_aops;
467                         /* Deal with crossing mountpoints */
468                         if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
469                                         fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
470                                 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
471                                         inode->i_op = &nfs_referral_inode_operations;
472                                 else
473                                         inode->i_op = &nfs_mountpoint_inode_operations;
474                                 inode->i_fop = NULL;
475                                 inode->i_flags |= S_AUTOMOUNT;
476                         }
477                 } else if (S_ISLNK(inode->i_mode)) {
478                         inode->i_op = &nfs_symlink_inode_operations;
479                         inode_nohighmem(inode);
480                 } else
481                         init_special_inode(inode, inode->i_mode, fattr->rdev);
482 
483                 memset(&inode->i_atime, 0, sizeof(inode->i_atime));
484                 memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
485                 memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
486                 inode->i_version = 0;
487                 inode->i_size = 0;
488                 clear_nlink(inode);
489                 inode->i_uid = make_kuid(&init_user_ns, -2);
490                 inode->i_gid = make_kgid(&init_user_ns, -2);
491                 inode->i_blocks = 0;
492                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
493                 nfsi->write_io = 0;
494                 nfsi->read_io = 0;
495 
496                 nfsi->read_cache_jiffies = fattr->time_start;
497                 nfsi->attr_gencount = fattr->gencount;
498                 if (fattr->valid & NFS_ATTR_FATTR_ATIME)
499                         inode->i_atime = fattr->atime;
500                 else if (nfs_server_capable(inode, NFS_CAP_ATIME))
501                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
502                 if (fattr->valid & NFS_ATTR_FATTR_MTIME)
503                         inode->i_mtime = fattr->mtime;
504                 else if (nfs_server_capable(inode, NFS_CAP_MTIME))
505                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
506                 if (fattr->valid & NFS_ATTR_FATTR_CTIME)
507                         inode->i_ctime = fattr->ctime;
508                 else if (nfs_server_capable(inode, NFS_CAP_CTIME))
509                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
510                 if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
511                         inode->i_version = fattr->change_attr;
512                 else
513                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
514                                 | NFS_INO_REVAL_PAGECACHE);
515                 if (fattr->valid & NFS_ATTR_FATTR_SIZE)
516                         inode->i_size = nfs_size_to_loff_t(fattr->size);
517                 else
518                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
519                                 | NFS_INO_REVAL_PAGECACHE);
520                 if (fattr->valid & NFS_ATTR_FATTR_NLINK)
521                         set_nlink(inode, fattr->nlink);
522                 else if (nfs_server_capable(inode, NFS_CAP_NLINK))
523                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
524                 if (fattr->valid & NFS_ATTR_FATTR_OWNER)
525                         inode->i_uid = fattr->uid;
526                 else if (nfs_server_capable(inode, NFS_CAP_OWNER))
527                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
528                 if (fattr->valid & NFS_ATTR_FATTR_GROUP)
529                         inode->i_gid = fattr->gid;
530                 else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
531                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
532                 if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
533                         inode->i_blocks = fattr->du.nfs2.blocks;
534                 if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
535                         /*
536                          * report the blocks in 512byte units
537                          */
538                         inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
539                 }
540 
541                 nfs_setsecurity(inode, fattr, label);
542 
543                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
544                 nfsi->attrtimeo_timestamp = now;
545                 nfsi->access_cache = RB_ROOT;
546 
547                 nfs_fscache_init_inode(inode);
548 
549                 unlock_new_inode(inode);
550         } else {
551                 int err = nfs_refresh_inode(inode, fattr);
552                 if (err < 0) {
553                         iput(inode);
554                         inode = ERR_PTR(err);
555                         goto out_no_inode;
556                 }
557         }
558         dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
559                 inode->i_sb->s_id,
560                 (unsigned long long)NFS_FILEID(inode),
561                 nfs_display_fhandle_hash(fh),
562                 atomic_read(&inode->i_count));
563 
564 out:
565         return inode;
566 
567 out_no_inode:
568         dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
569         goto out;
570 }
571 EXPORT_SYMBOL_GPL(nfs_fhget);
572 
573 #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)
574 
575 int
576 nfs_setattr(struct dentry *dentry, struct iattr *attr)
577 {
578         struct inode *inode = d_inode(dentry);
579         struct nfs_fattr *fattr;
580         int error = 0;
581 
582         nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
583 
584         /* skip mode change if it's just for clearing setuid/setgid */
585         if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
586                 attr->ia_valid &= ~ATTR_MODE;
587 
588         if (attr->ia_valid & ATTR_SIZE) {
589                 BUG_ON(!S_ISREG(inode->i_mode));
590 
591                 error = inode_newsize_ok(inode, attr->ia_size);
592                 if (error)
593                         return error;
594 
595                 if (attr->ia_size == i_size_read(inode))
596                         attr->ia_valid &= ~ATTR_SIZE;
597         }
598 
599         /* Optimization: if the end result is no change, don't RPC */
600         attr->ia_valid &= NFS_VALID_ATTRS;
601         if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
602                 return 0;
603 
604         trace_nfs_setattr_enter(inode);
605 
606         /* Write all dirty data */
607         if (S_ISREG(inode->i_mode))
608                 nfs_sync_inode(inode);
609 
610         fattr = nfs_alloc_fattr();
611         if (fattr == NULL) {
612                 error = -ENOMEM;
613                 goto out;
614         }
615 
616         /*
617          * Return any delegations if we're going to change ACLs
618          */
619         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
620                 NFS_PROTO(inode)->return_delegation(inode);
621         error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
622         if (error == 0)
623                 error = nfs_refresh_inode(inode, fattr);
624         nfs_free_fattr(fattr);
625 out:
626         trace_nfs_setattr_exit(inode, error);
627         return error;
628 }
629 EXPORT_SYMBOL_GPL(nfs_setattr);
630 
631 /**
632  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
633  * @inode: inode of the file used
634  * @offset: file offset to start truncating
635  *
636  * This is a copy of the common vmtruncate, but with the locking
637  * corrected to take into account the fact that NFS requires
638  * inode->i_size to be updated under the inode->i_lock.
639  * Note: must be called with inode->i_lock held!
640  */
641 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
642 {
643         int err;
644 
645         err = inode_newsize_ok(inode, offset);
646         if (err)
647                 goto out;
648 
649         i_size_write(inode, offset);
650         /* Optimisation */
651         if (offset == 0)
652                 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
653 
654         spin_unlock(&inode->i_lock);
655         truncate_pagecache(inode, offset);
656         spin_lock(&inode->i_lock);
657 out:
658         return err;
659 }
660 
661 /**
662  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
663  * @inode: pointer to struct inode
664  * @attr: pointer to struct iattr
665  *
666  * Note: we do this in the *proc.c in order to ensure that
667  *       it works for things like exclusive creates too.
668  */
669 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
670                 struct nfs_fattr *fattr)
671 {
672         /* Barrier: bump the attribute generation count. */
673         nfs_fattr_set_barrier(fattr);
674 
675         spin_lock(&inode->i_lock);
676         NFS_I(inode)->attr_gencount = fattr->gencount;
677         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
678                 if ((attr->ia_valid & ATTR_MODE) != 0) {
679                         int mode = attr->ia_mode & S_IALLUGO;
680                         mode |= inode->i_mode & ~S_IALLUGO;
681                         inode->i_mode = mode;
682                 }
683                 if ((attr->ia_valid & ATTR_UID) != 0)
684                         inode->i_uid = attr->ia_uid;
685                 if ((attr->ia_valid & ATTR_GID) != 0)
686                         inode->i_gid = attr->ia_gid;
687                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
688                                 | NFS_INO_INVALID_ACL);
689         }
690         if ((attr->ia_valid & ATTR_SIZE) != 0) {
691                 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
692                 nfs_vmtruncate(inode, attr->ia_size);
693         }
694         if (fattr->valid)
695                 nfs_update_inode(inode, fattr);
696         else
697                 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
698         spin_unlock(&inode->i_lock);
699 }
700 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
701 
702 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
703 {
704         struct dentry *parent;
705 
706         if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
707                 return;
708         parent = dget_parent(dentry);
709         nfs_force_use_readdirplus(d_inode(parent));
710         dput(parent);
711 }
712 
713 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
714 {
715         struct dentry *parent;
716 
717         if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
718                 return;
719         parent = dget_parent(dentry);
720         nfs_advise_use_readdirplus(d_inode(parent));
721         dput(parent);
722 }
723 
724 static bool nfs_need_revalidate_inode(struct inode *inode)
725 {
726         if (NFS_I(inode)->cache_validity &
727                         (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
728                 return true;
729         if (nfs_attribute_cache_expired(inode))
730                 return true;
731         return false;
732 }
733 
734 int nfs_getattr(const struct path *path, struct kstat *stat,
735                 u32 request_mask, unsigned int query_flags)
736 {
737         struct inode *inode = d_inode(path->dentry);
738         int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
739         int err = 0;
740 
741         trace_nfs_getattr_enter(inode);
742         /* Flush out writes to the server in order to update c/mtime.  */
743         if (S_ISREG(inode->i_mode)) {
744                 err = filemap_write_and_wait(inode->i_mapping);
745                 if (err)
746                         goto out;
747         }
748 
749         /*
750          * We may force a getattr if the user cares about atime.
751          *
752          * Note that we only have to check the vfsmount flags here:
753          *  - NFS always sets S_NOATIME by so checking it would give a
754          *    bogus result
755          *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
756          *    no point in checking those.
757          */
758         if ((path->mnt->mnt_flags & MNT_NOATIME) ||
759             ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
760                 need_atime = 0;
761 
762         if (need_atime || nfs_need_revalidate_inode(inode)) {
763                 struct nfs_server *server = NFS_SERVER(inode);
764 
765                 if (!(server->flags & NFS_MOUNT_NOAC))
766                         nfs_readdirplus_parent_cache_miss(path->dentry);
767                 else
768                         nfs_readdirplus_parent_cache_hit(path->dentry);
769                 err = __nfs_revalidate_inode(server, inode);
770         } else
771                 nfs_readdirplus_parent_cache_hit(path->dentry);
772         if (!err) {
773                 generic_fillattr(inode, stat);
774                 stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
775                 if (S_ISDIR(inode->i_mode))
776                         stat->blksize = NFS_SERVER(inode)->dtsize;
777         }
778 out:
779         trace_nfs_getattr_exit(inode, err);
780         return err;
781 }
782 EXPORT_SYMBOL_GPL(nfs_getattr);
783 
784 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
785 {
786         refcount_set(&l_ctx->count, 1);
787         l_ctx->lockowner = current->files;
788         INIT_LIST_HEAD(&l_ctx->list);
789         atomic_set(&l_ctx->io_count, 0);
790 }
791 
792 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
793 {
794         struct nfs_lock_context *head = &ctx->lock_context;
795         struct nfs_lock_context *pos = head;
796 
797         do {
798                 if (pos->lockowner != current->files)
799                         continue;
800                 refcount_inc(&pos->count);
801                 return pos;
802         } while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
803         return NULL;
804 }
805 
806 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
807 {
808         struct nfs_lock_context *res, *new = NULL;
809         struct inode *inode = d_inode(ctx->dentry);
810 
811         spin_lock(&inode->i_lock);
812         res = __nfs_find_lock_context(ctx);
813         if (res == NULL) {
814                 spin_unlock(&inode->i_lock);
815                 new = kmalloc(sizeof(*new), GFP_KERNEL);
816                 if (new == NULL)
817                         return ERR_PTR(-ENOMEM);
818                 nfs_init_lock_context(new);
819                 spin_lock(&inode->i_lock);
820                 res = __nfs_find_lock_context(ctx);
821                 if (res == NULL) {
822                         list_add_tail(&new->list, &ctx->lock_context.list);
823                         new->open_context = ctx;
824                         res = new;
825                         new = NULL;
826                 }
827         }
828         spin_unlock(&inode->i_lock);
829         kfree(new);
830         return res;
831 }
832 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
833 
834 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
835 {
836         struct nfs_open_context *ctx = l_ctx->open_context;
837         struct inode *inode = d_inode(ctx->dentry);
838 
839         if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
840                 return;
841         list_del(&l_ctx->list);
842         spin_unlock(&inode->i_lock);
843         kfree(l_ctx);
844 }
845 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
846 
847 /**
848  * nfs_close_context - Common close_context() routine NFSv2/v3
849  * @ctx: pointer to context
850  * @is_sync: is this a synchronous close
851  *
852  * Ensure that the attributes are up to date if we're mounted
853  * with close-to-open semantics and we have cached data that will
854  * need to be revalidated on open.
855  */
856 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
857 {
858         struct nfs_inode *nfsi;
859         struct inode *inode;
860         struct nfs_server *server;
861 
862         if (!(ctx->mode & FMODE_WRITE))
863                 return;
864         if (!is_sync)
865                 return;
866         inode = d_inode(ctx->dentry);
867         if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
868                 return;
869         nfsi = NFS_I(inode);
870         if (inode->i_mapping->nrpages == 0)
871                 return;
872         if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
873                 return;
874         if (!list_empty(&nfsi->open_files))
875                 return;
876         server = NFS_SERVER(inode);
877         if (server->flags & NFS_MOUNT_NOCTO)
878                 return;
879         nfs_revalidate_inode(server, inode);
880 }
881 EXPORT_SYMBOL_GPL(nfs_close_context);
882 
883 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
884                                                 fmode_t f_mode,
885                                                 struct file *filp)
886 {
887         struct nfs_open_context *ctx;
888         struct rpc_cred *cred = rpc_lookup_cred();
889         if (IS_ERR(cred))
890                 return ERR_CAST(cred);
891 
892         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
893         if (!ctx) {
894                 put_rpccred(cred);
895                 return ERR_PTR(-ENOMEM);
896         }
897         nfs_sb_active(dentry->d_sb);
898         ctx->dentry = dget(dentry);
899         ctx->cred = cred;
900         ctx->state = NULL;
901         ctx->mode = f_mode;
902         ctx->flags = 0;
903         ctx->error = 0;
904         ctx->flock_owner = (fl_owner_t)filp;
905         nfs_init_lock_context(&ctx->lock_context);
906         ctx->lock_context.open_context = ctx;
907         INIT_LIST_HEAD(&ctx->list);
908         ctx->mdsthreshold = NULL;
909         return ctx;
910 }
911 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
912 
913 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
914 {
915         if (ctx != NULL)
916                 refcount_inc(&ctx->lock_context.count);
917         return ctx;
918 }
919 EXPORT_SYMBOL_GPL(get_nfs_open_context);
920 
921 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
922 {
923         struct inode *inode = d_inode(ctx->dentry);
924         struct super_block *sb = ctx->dentry->d_sb;
925 
926         if (!list_empty(&ctx->list)) {
927                 if (!refcount_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
928                         return;
929                 list_del(&ctx->list);
930                 spin_unlock(&inode->i_lock);
931         } else if (!refcount_dec_and_test(&ctx->lock_context.count))
932                 return;
933         if (inode != NULL)
934                 NFS_PROTO(inode)->close_context(ctx, is_sync);
935         if (ctx->cred != NULL)
936                 put_rpccred(ctx->cred);
937         dput(ctx->dentry);
938         nfs_sb_deactive(sb);
939         kfree(ctx->mdsthreshold);
940         kfree(ctx);
941 }
942 
943 void put_nfs_open_context(struct nfs_open_context *ctx)
944 {
945         __put_nfs_open_context(ctx, 0);
946 }
947 EXPORT_SYMBOL_GPL(put_nfs_open_context);
948 
949 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
950 {
951         __put_nfs_open_context(ctx, 1);
952 }
953 
954 /*
955  * Ensure that mmap has a recent RPC credential for use when writing out
956  * shared pages
957  */
958 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
959 {
960         struct inode *inode = d_inode(ctx->dentry);
961         struct nfs_inode *nfsi = NFS_I(inode);
962 
963         spin_lock(&inode->i_lock);
964         if (ctx->mode & FMODE_WRITE)
965                 list_add(&ctx->list, &nfsi->open_files);
966         else
967                 list_add_tail(&ctx->list, &nfsi->open_files);
968         spin_unlock(&inode->i_lock);
969 }
970 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
971 
972 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
973 {
974         filp->private_data = get_nfs_open_context(ctx);
975         if (list_empty(&ctx->list))
976                 nfs_inode_attach_open_context(ctx);
977 }
978 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
979 
980 /*
981  * Given an inode, search for an open context with the desired characteristics
982  */
983 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
984 {
985         struct nfs_inode *nfsi = NFS_I(inode);
986         struct nfs_open_context *pos, *ctx = NULL;
987 
988         spin_lock(&inode->i_lock);
989         list_for_each_entry(pos, &nfsi->open_files, list) {
990                 if (cred != NULL && pos->cred != cred)
991                         continue;
992                 if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
993                         continue;
994                 ctx = get_nfs_open_context(pos);
995                 break;
996         }
997         spin_unlock(&inode->i_lock);
998         return ctx;
999 }
1000 
1001 void nfs_file_clear_open_context(struct file *filp)
1002 {
1003         struct nfs_open_context *ctx = nfs_file_open_context(filp);
1004 
1005         if (ctx) {
1006                 struct inode *inode = d_inode(ctx->dentry);
1007 
1008                 /*
1009                  * We fatal error on write before. Try to writeback
1010                  * every page again.
1011                  */
1012                 if (ctx->error < 0)
1013                         invalidate_inode_pages2(inode->i_mapping);
1014                 filp->private_data = NULL;
1015                 spin_lock(&inode->i_lock);
1016                 list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
1017                 spin_unlock(&inode->i_lock);
1018                 put_nfs_open_context_sync(ctx);
1019         }
1020 }
1021 
1022 /*
1023  * These allocate and release file read/write context information.
1024  */
1025 int nfs_open(struct inode *inode, struct file *filp)
1026 {
1027         struct nfs_open_context *ctx;
1028 
1029         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
1030         if (IS_ERR(ctx))
1031                 return PTR_ERR(ctx);
1032         nfs_file_set_open_context(filp, ctx);
1033         put_nfs_open_context(ctx);
1034         nfs_fscache_open_file(inode, filp);
1035         return 0;
1036 }
1037 
1038 /*
1039  * This function is called whenever some part of NFS notices that
1040  * the cached attributes have to be refreshed.
1041  */
1042 int
1043 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1044 {
1045         int              status = -ESTALE;
1046         struct nfs4_label *label = NULL;
1047         struct nfs_fattr *fattr = NULL;
1048         struct nfs_inode *nfsi = NFS_I(inode);
1049 
1050         dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1051                 inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1052 
1053         trace_nfs_revalidate_inode_enter(inode);
1054 
1055         if (is_bad_inode(inode))
1056                 goto out;
1057         if (NFS_STALE(inode))
1058                 goto out;
1059 
1060         /* pNFS: Attributes aren't updated until we layoutcommit */
1061         if (S_ISREG(inode->i_mode)) {
1062                 status = pnfs_sync_inode(inode, false);
1063                 if (status)
1064                         goto out;
1065         }
1066 
1067         status = -ENOMEM;
1068         fattr = nfs_alloc_fattr();
1069         if (fattr == NULL)
1070                 goto out;
1071 
1072         nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1073 
1074         label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1075         if (IS_ERR(label)) {
1076                 status = PTR_ERR(label);
1077                 goto out;
1078         }
1079 
1080         status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, label);
1081         if (status != 0) {
1082                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1083                          inode->i_sb->s_id,
1084                          (unsigned long long)NFS_FILEID(inode), status);
1085                 if (status == -ESTALE) {
1086                         nfs_zap_caches(inode);
1087                         if (!S_ISDIR(inode->i_mode))
1088                                 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1089                 }
1090                 goto err_out;
1091         }
1092 
1093         status = nfs_refresh_inode(inode, fattr);
1094         if (status) {
1095                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1096                          inode->i_sb->s_id,
1097                          (unsigned long long)NFS_FILEID(inode), status);
1098                 goto err_out;
1099         }
1100 
1101         if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1102                 nfs_zap_acl_cache(inode);
1103 
1104         nfs_setsecurity(inode, fattr, label);
1105 
1106         dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1107                 inode->i_sb->s_id,
1108                 (unsigned long long)NFS_FILEID(inode));
1109 
1110 err_out:
1111         nfs4_label_free(label);
1112 out:
1113         nfs_free_fattr(fattr);
1114         trace_nfs_revalidate_inode_exit(inode, status);
1115         return status;
1116 }
1117 
1118 int nfs_attribute_cache_expired(struct inode *inode)
1119 {
1120         if (nfs_have_delegated_attributes(inode))
1121                 return 0;
1122         return nfs_attribute_timeout(inode);
1123 }
1124 
1125 /**
1126  * nfs_revalidate_inode - Revalidate the inode attributes
1127  * @server - pointer to nfs_server struct
1128  * @inode - pointer to inode struct
1129  *
1130  * Updates inode attribute information by retrieving the data from the server.
1131  */
1132 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1133 {
1134         if (!nfs_need_revalidate_inode(inode))
1135                 return NFS_STALE(inode) ? -ESTALE : 0;
1136         return __nfs_revalidate_inode(server, inode);
1137 }
1138 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1139 
1140 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1141 {
1142         struct nfs_inode *nfsi = NFS_I(inode);
1143         int ret;
1144 
1145         if (mapping->nrpages != 0) {
1146                 if (S_ISREG(inode->i_mode)) {
1147                         unmap_mapping_range(mapping, 0, 0, 0);
1148                         ret = nfs_sync_mapping(mapping);
1149                         if (ret < 0)
1150                                 return ret;
1151                 }
1152                 ret = invalidate_inode_pages2(mapping);
1153                 if (ret < 0)
1154                         return ret;
1155         }
1156         if (S_ISDIR(inode->i_mode)) {
1157                 spin_lock(&inode->i_lock);
1158                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1159                 spin_unlock(&inode->i_lock);
1160         }
1161         nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1162         nfs_fscache_wait_on_invalidate(inode);
1163 
1164         dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1165                         inode->i_sb->s_id,
1166                         (unsigned long long)NFS_FILEID(inode));
1167         return 0;
1168 }
1169 
1170 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1171 {
1172         return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1173                 NFS_STALE(inode);
1174 }
1175 
1176 int nfs_revalidate_mapping_rcu(struct inode *inode)
1177 {
1178         struct nfs_inode *nfsi = NFS_I(inode);
1179         unsigned long *bitlock = &nfsi->flags;
1180         int ret = 0;
1181 
1182         if (IS_SWAPFILE(inode))
1183                 goto out;
1184         if (nfs_mapping_need_revalidate_inode(inode)) {
1185                 ret = -ECHILD;
1186                 goto out;
1187         }
1188         spin_lock(&inode->i_lock);
1189         if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1190             (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1191                 ret = -ECHILD;
1192         spin_unlock(&inode->i_lock);
1193 out:
1194         return ret;
1195 }
1196 
1197 /**
1198  * nfs_revalidate_mapping - Revalidate the pagecache
1199  * @inode - pointer to host inode
1200  * @mapping - pointer to mapping
1201  */
1202 int nfs_revalidate_mapping(struct inode *inode,
1203                 struct address_space *mapping)
1204 {
1205         struct nfs_inode *nfsi = NFS_I(inode);
1206         unsigned long *bitlock = &nfsi->flags;
1207         int ret = 0;
1208 
1209         /* swapfiles are not supposed to be shared. */
1210         if (IS_SWAPFILE(inode))
1211                 goto out;
1212 
1213         if (nfs_mapping_need_revalidate_inode(inode)) {
1214                 ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1215                 if (ret < 0)
1216                         goto out;
1217         }
1218 
1219         /*
1220          * We must clear NFS_INO_INVALID_DATA first to ensure that
1221          * invalidations that come in while we're shooting down the mappings
1222          * are respected. But, that leaves a race window where one revalidator
1223          * can clear the flag, and then another checks it before the mapping
1224          * gets invalidated. Fix that by serializing access to this part of
1225          * the function.
1226          *
1227          * At the same time, we need to allow other tasks to see whether we
1228          * might be in the middle of invalidating the pages, so we only set
1229          * the bit lock here if it looks like we're going to be doing that.
1230          */
1231         for (;;) {
1232                 ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1233                                          nfs_wait_bit_killable, TASK_KILLABLE);
1234                 if (ret)
1235                         goto out;
1236                 spin_lock(&inode->i_lock);
1237                 if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1238                         spin_unlock(&inode->i_lock);
1239                         continue;
1240                 }
1241                 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1242                         break;
1243                 spin_unlock(&inode->i_lock);
1244                 goto out;
1245         }
1246 
1247         set_bit(NFS_INO_INVALIDATING, bitlock);
1248         smp_wmb();
1249         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1250         spin_unlock(&inode->i_lock);
1251         trace_nfs_invalidate_mapping_enter(inode);
1252         ret = nfs_invalidate_mapping(inode, mapping);
1253         trace_nfs_invalidate_mapping_exit(inode, ret);
1254 
1255         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1256         smp_mb__after_atomic();
1257         wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1258 out:
1259         return ret;
1260 }
1261 
1262 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1263 {
1264         struct inode *inode = &nfsi->vfs_inode;
1265 
1266         assert_spin_locked(&inode->i_lock);
1267 
1268         if (!S_ISREG(inode->i_mode))
1269                 return false;
1270         if (list_empty(&nfsi->open_files))
1271                 return false;
1272         /* Note: This relies on nfsi->open_files being ordered with writers
1273          *       being placed at the head of the list.
1274          *       See nfs_inode_attach_open_context()
1275          */
1276         return (list_first_entry(&nfsi->open_files,
1277                         struct nfs_open_context,
1278                         list)->mode & FMODE_WRITE) == FMODE_WRITE;
1279 }
1280 
1281 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1282 {
1283         return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1284 }
1285 
1286 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1287 {
1288         unsigned long ret = 0;
1289 
1290         if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1291                         && (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1292                         && inode->i_version == fattr->pre_change_attr) {
1293                 inode->i_version = fattr->change_attr;
1294                 if (S_ISDIR(inode->i_mode))
1295                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1296                 ret |= NFS_INO_INVALID_ATTR;
1297         }
1298         /* If we have atomic WCC data, we may update some attributes */
1299         if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1300                         && (fattr->valid & NFS_ATTR_FATTR_CTIME)
1301                         && timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1302                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1303                 ret |= NFS_INO_INVALID_ATTR;
1304         }
1305 
1306         if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1307                         && (fattr->valid & NFS_ATTR_FATTR_MTIME)
1308                         && timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1309                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1310                 if (S_ISDIR(inode->i_mode))
1311                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1312                 ret |= NFS_INO_INVALID_ATTR;
1313         }
1314         if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1315                         && (fattr->valid & NFS_ATTR_FATTR_SIZE)
1316                         && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1317                         && !nfs_have_writebacks(inode)) {
1318                 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1319                 ret |= NFS_INO_INVALID_ATTR;
1320         }
1321 
1322         return ret;
1323 }
1324 
1325 /**
1326  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1327  * @inode - pointer to inode
1328  * @fattr - updated attributes
1329  *
1330  * Verifies the attribute cache. If we have just changed the attributes,
1331  * so that fattr carries weak cache consistency data, then it may
1332  * also update the ctime/mtime/change_attribute.
1333  */
1334 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1335 {
1336         struct nfs_inode *nfsi = NFS_I(inode);
1337         loff_t cur_size, new_isize;
1338         unsigned long invalid = 0;
1339 
1340 
1341         if (nfs_have_delegated_attributes(inode))
1342                 return 0;
1343         /* Has the inode gone and changed behind our back? */
1344         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1345                 return -ESTALE;
1346         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1347                 return -ESTALE;
1348 
1349         if (!nfs_file_has_buffered_writers(nfsi)) {
1350                 /* Verify a few of the more important attributes */
1351                 if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && inode->i_version != fattr->change_attr)
1352                         invalid |= NFS_INO_INVALID_ATTR | NFS_INO_REVAL_PAGECACHE;
1353 
1354                 if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1355                         invalid |= NFS_INO_INVALID_ATTR;
1356 
1357                 if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
1358                         invalid |= NFS_INO_INVALID_ATTR;
1359 
1360                 if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1361                         cur_size = i_size_read(inode);
1362                         new_isize = nfs_size_to_loff_t(fattr->size);
1363                         if (cur_size != new_isize)
1364                                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1365                 }
1366         }
1367 
1368         /* Have any file permissions changed? */
1369         if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1370                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1371         if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1372                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1373         if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1374                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1375 
1376         /* Has the link count changed? */
1377         if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1378                 invalid |= NFS_INO_INVALID_ATTR;
1379 
1380         if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1381                 invalid |= NFS_INO_INVALID_ATIME;
1382 
1383         if (invalid != 0)
1384                 nfs_set_cache_invalid(inode, invalid | NFS_INO_REVAL_FORCED);
1385 
1386         nfsi->read_cache_jiffies = fattr->time_start;
1387         return 0;
1388 }
1389 
1390 static atomic_long_t nfs_attr_generation_counter;
1391 
1392 static unsigned long nfs_read_attr_generation_counter(void)
1393 {
1394         return atomic_long_read(&nfs_attr_generation_counter);
1395 }
1396 
1397 unsigned long nfs_inc_attr_generation_counter(void)
1398 {
1399         return atomic_long_inc_return(&nfs_attr_generation_counter);
1400 }
1401 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1402 
1403 void nfs_fattr_init(struct nfs_fattr *fattr)
1404 {
1405         fattr->valid = 0;
1406         fattr->time_start = jiffies;
1407         fattr->gencount = nfs_inc_attr_generation_counter();
1408         fattr->owner_name = NULL;
1409         fattr->group_name = NULL;
1410 }
1411 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1412 
1413 /**
1414  * nfs_fattr_set_barrier
1415  * @fattr: attributes
1416  *
1417  * Used to set a barrier after an attribute was updated. This
1418  * barrier ensures that older attributes from RPC calls that may
1419  * have raced with our update cannot clobber these new values.
1420  * Note that you are still responsible for ensuring that other
1421  * operations which change the attribute on the server do not
1422  * collide.
1423  */
1424 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1425 {
1426         fattr->gencount = nfs_inc_attr_generation_counter();
1427 }
1428 
1429 struct nfs_fattr *nfs_alloc_fattr(void)
1430 {
1431         struct nfs_fattr *fattr;
1432 
1433         fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1434         if (fattr != NULL)
1435                 nfs_fattr_init(fattr);
1436         return fattr;
1437 }
1438 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1439 
1440 struct nfs_fh *nfs_alloc_fhandle(void)
1441 {
1442         struct nfs_fh *fh;
1443 
1444         fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1445         if (fh != NULL)
1446                 fh->size = 0;
1447         return fh;
1448 }
1449 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1450 
1451 #ifdef NFS_DEBUG
1452 /*
1453  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1454  *                             in the same way that wireshark does
1455  *
1456  * @fh: file handle
1457  *
1458  * For debugging only.
1459  */
1460 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1461 {
1462         /* wireshark uses 32-bit AUTODIN crc and does a bitwise
1463          * not on the result */
1464         return nfs_fhandle_hash(fh);
1465 }
1466 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1467 
1468 /*
1469  * _nfs_display_fhandle - display an NFS file handle on the console
1470  *
1471  * @fh: file handle to display
1472  * @caption: display caption
1473  *
1474  * For debugging only.
1475  */
1476 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1477 {
1478         unsigned short i;
1479 
1480         if (fh == NULL || fh->size == 0) {
1481                 printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1482                 return;
1483         }
1484 
1485         printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1486                caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1487         for (i = 0; i < fh->size; i += 16) {
1488                 __be32 *pos = (__be32 *)&fh->data[i];
1489 
1490                 switch ((fh->size - i - 1) >> 2) {
1491                 case 0:
1492                         printk(KERN_DEFAULT " %08x\n",
1493                                 be32_to_cpup(pos));
1494                         break;
1495                 case 1:
1496                         printk(KERN_DEFAULT " %08x %08x\n",
1497                                 be32_to_cpup(pos), be32_to_cpup(pos + 1));
1498                         break;
1499                 case 2:
1500                         printk(KERN_DEFAULT " %08x %08x %08x\n",
1501                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1502                                 be32_to_cpup(pos + 2));
1503                         break;
1504                 default:
1505                         printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1506                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1507                                 be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1508                 }
1509         }
1510 }
1511 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1512 #endif
1513 
1514 /**
1515  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1516  * @inode - pointer to inode
1517  * @fattr - attributes
1518  *
1519  * Attempt to divine whether or not an RPC call reply carrying stale
1520  * attributes got scheduled after another call carrying updated ones.
1521  *
1522  * To do so, the function first assumes that a more recent ctime means
1523  * that the attributes in fattr are newer, however it also attempt to
1524  * catch the case where ctime either didn't change, or went backwards
1525  * (if someone reset the clock on the server) by looking at whether
1526  * or not this RPC call was started after the inode was last updated.
1527  * Note also the check for wraparound of 'attr_gencount'
1528  *
1529  * The function returns 'true' if it thinks the attributes in 'fattr' are
1530  * more recent than the ones cached in the inode.
1531  *
1532  */
1533 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1534 {
1535         const struct nfs_inode *nfsi = NFS_I(inode);
1536 
1537         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1538                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1539 }
1540 
1541 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1542 {
1543         int ret;
1544 
1545         trace_nfs_refresh_inode_enter(inode);
1546 
1547         if (nfs_inode_attrs_need_update(inode, fattr))
1548                 ret = nfs_update_inode(inode, fattr);
1549         else
1550                 ret = nfs_check_inode_attributes(inode, fattr);
1551 
1552         trace_nfs_refresh_inode_exit(inode, ret);
1553         return ret;
1554 }
1555 
1556 /**
1557  * nfs_refresh_inode - try to update the inode attribute cache
1558  * @inode - pointer to inode
1559  * @fattr - updated attributes
1560  *
1561  * Check that an RPC call that returned attributes has not overlapped with
1562  * other recent updates of the inode metadata, then decide whether it is
1563  * safe to do a full update of the inode attributes, or whether just to
1564  * call nfs_check_inode_attributes.
1565  */
1566 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1567 {
1568         int status;
1569 
1570         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1571                 return 0;
1572         spin_lock(&inode->i_lock);
1573         status = nfs_refresh_inode_locked(inode, fattr);
1574         spin_unlock(&inode->i_lock);
1575 
1576         return status;
1577 }
1578 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1579 
1580 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1581 {
1582         unsigned long invalid = NFS_INO_INVALID_ATTR;
1583 
1584         if (S_ISDIR(inode->i_mode))
1585                 invalid |= NFS_INO_INVALID_DATA;
1586         nfs_set_cache_invalid(inode, invalid);
1587         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1588                 return 0;
1589         return nfs_refresh_inode_locked(inode, fattr);
1590 }
1591 
1592 /**
1593  * nfs_post_op_update_inode - try to update the inode attribute cache
1594  * @inode - pointer to inode
1595  * @fattr - updated attributes
1596  *
1597  * After an operation that has changed the inode metadata, mark the
1598  * attribute cache as being invalid, then try to update it.
1599  *
1600  * NB: if the server didn't return any post op attributes, this
1601  * function will force the retrieval of attributes before the next
1602  * NFS request.  Thus it should be used only for operations that
1603  * are expected to change one or more attributes, to avoid
1604  * unnecessary NFS requests and trips through nfs_update_inode().
1605  */
1606 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1607 {
1608         int status;
1609 
1610         spin_lock(&inode->i_lock);
1611         nfs_fattr_set_barrier(fattr);
1612         status = nfs_post_op_update_inode_locked(inode, fattr);
1613         spin_unlock(&inode->i_lock);
1614 
1615         return status;
1616 }
1617 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1618 
1619 /**
1620  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1621  * @inode - pointer to inode
1622  * @fattr - updated attributes
1623  *
1624  * After an operation that has changed the inode metadata, mark the
1625  * attribute cache as being invalid, then try to update it. Fake up
1626  * weak cache consistency data, if none exist.
1627  *
1628  * This function is mainly designed to be used by the ->write_done() functions.
1629  */
1630 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1631 {
1632         int status;
1633 
1634         /* Don't do a WCC update if these attributes are already stale */
1635         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1636                         !nfs_inode_attrs_need_update(inode, fattr)) {
1637                 fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1638                                 | NFS_ATTR_FATTR_PRESIZE
1639                                 | NFS_ATTR_FATTR_PREMTIME
1640                                 | NFS_ATTR_FATTR_PRECTIME);
1641                 goto out_noforce;
1642         }
1643         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1644                         (fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1645                 fattr->pre_change_attr = inode->i_version;
1646                 fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1647         }
1648         if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1649                         (fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1650                 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1651                 fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1652         }
1653         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1654                         (fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1655                 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1656                 fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1657         }
1658         if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1659                         (fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1660                 fattr->pre_size = i_size_read(inode);
1661                 fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1662         }
1663 out_noforce:
1664         status = nfs_post_op_update_inode_locked(inode, fattr);
1665         return status;
1666 }
1667 
1668 /**
1669  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1670  * @inode - pointer to inode
1671  * @fattr - updated attributes
1672  *
1673  * After an operation that has changed the inode metadata, mark the
1674  * attribute cache as being invalid, then try to update it. Fake up
1675  * weak cache consistency data, if none exist.
1676  *
1677  * This function is mainly designed to be used by the ->write_done() functions.
1678  */
1679 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1680 {
1681         int status;
1682 
1683         spin_lock(&inode->i_lock);
1684         nfs_fattr_set_barrier(fattr);
1685         status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1686         spin_unlock(&inode->i_lock);
1687         return status;
1688 }
1689 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1690 
1691 
1692 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1693                                     struct nfs_fattr *fattr)
1694 {
1695         bool ret1 = true, ret2 = true;
1696 
1697         if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1698                 ret1 = (nfsi->fileid == fattr->fileid);
1699         if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1700                 ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1701         return ret1 || ret2;
1702 }
1703 
1704 /*
1705  * Many nfs protocol calls return the new file attributes after
1706  * an operation.  Here we update the inode to reflect the state
1707  * of the server's inode.
1708  *
1709  * This is a bit tricky because we have to make sure all dirty pages
1710  * have been sent off to the server before calling invalidate_inode_pages.
1711  * To make sure no other process adds more write requests while we try
1712  * our best to flush them, we make them sleep during the attribute refresh.
1713  *
1714  * A very similar scenario holds for the dir cache.
1715  */
1716 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1717 {
1718         struct nfs_server *server;
1719         struct nfs_inode *nfsi = NFS_I(inode);
1720         loff_t cur_isize, new_isize;
1721         unsigned long invalid = 0;
1722         unsigned long now = jiffies;
1723         unsigned long save_cache_validity;
1724         bool have_writers = nfs_file_has_buffered_writers(nfsi);
1725         bool cache_revalidated = true;
1726 
1727         dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1728                         __func__, inode->i_sb->s_id, inode->i_ino,
1729                         nfs_display_fhandle_hash(NFS_FH(inode)),
1730                         atomic_read(&inode->i_count), fattr->valid);
1731 
1732         if (!nfs_fileid_valid(nfsi, fattr)) {
1733                 printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1734                         "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1735                         NFS_SERVER(inode)->nfs_client->cl_hostname,
1736                         inode->i_sb->s_id, (long long)nfsi->fileid,
1737                         (long long)fattr->fileid);
1738                 goto out_err;
1739         }
1740 
1741         /*
1742          * Make sure the inode's type hasn't changed.
1743          */
1744         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1745                 /*
1746                 * Big trouble! The inode has become a different object.
1747                 */
1748                 printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1749                                 __func__, inode->i_ino, inode->i_mode, fattr->mode);
1750                 goto out_err;
1751         }
1752 
1753         server = NFS_SERVER(inode);
1754         /* Update the fsid? */
1755         if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1756                         !nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1757                         !IS_AUTOMOUNT(inode))
1758                 server->fsid = fattr->fsid;
1759 
1760         /*
1761          * Update the read time so we don't revalidate too often.
1762          */
1763         nfsi->read_cache_jiffies = fattr->time_start;
1764 
1765         save_cache_validity = nfsi->cache_validity;
1766         nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1767                         | NFS_INO_INVALID_ATIME
1768                         | NFS_INO_REVAL_FORCED
1769                         | NFS_INO_REVAL_PAGECACHE);
1770 
1771         /* Do atomic weak cache consistency updates */
1772         invalid |= nfs_wcc_update_inode(inode, fattr);
1773 
1774         if (pnfs_layoutcommit_outstanding(inode)) {
1775                 nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1776                 cache_revalidated = false;
1777         }
1778 
1779         /* More cache consistency checks */
1780         if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1781                 if (inode->i_version != fattr->change_attr) {
1782                         dprintk("NFS: change_attr change on server for file %s/%ld\n",
1783                                         inode->i_sb->s_id, inode->i_ino);
1784                         /* Could it be a race with writeback? */
1785                         if (!have_writers) {
1786                                 invalid |= NFS_INO_INVALID_ATTR
1787                                         | NFS_INO_INVALID_DATA
1788                                         | NFS_INO_INVALID_ACCESS
1789                                         | NFS_INO_INVALID_ACL;
1790                                 if (S_ISDIR(inode->i_mode))
1791                                         nfs_force_lookup_revalidate(inode);
1792                         }
1793                         inode->i_version = fattr->change_attr;
1794                 }
1795         } else {
1796                 nfsi->cache_validity |= save_cache_validity;
1797                 cache_revalidated = false;
1798         }
1799 
1800         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1801                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1802         } else if (server->caps & NFS_CAP_MTIME) {
1803                 nfsi->cache_validity |= save_cache_validity &
1804                                 (NFS_INO_INVALID_ATTR
1805                                 | NFS_INO_REVAL_FORCED);
1806                 cache_revalidated = false;
1807         }
1808 
1809         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1810                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1811         } else if (server->caps & NFS_CAP_CTIME) {
1812                 nfsi->cache_validity |= save_cache_validity &
1813                                 (NFS_INO_INVALID_ATTR
1814                                 | NFS_INO_REVAL_FORCED);
1815                 cache_revalidated = false;
1816         }
1817 
1818         /* Check if our cached file size is stale */
1819         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1820                 new_isize = nfs_size_to_loff_t(fattr->size);
1821                 cur_isize = i_size_read(inode);
1822                 if (new_isize != cur_isize) {
1823                         /* Do we perhaps have any outstanding writes, or has
1824                          * the file grown beyond our last write? */
1825                         if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
1826                                 i_size_write(inode, new_isize);
1827                                 if (!have_writers)
1828                                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1829                         }
1830                         dprintk("NFS: isize change on server for file %s/%ld "
1831                                         "(%Ld to %Ld)\n",
1832                                         inode->i_sb->s_id,
1833                                         inode->i_ino,
1834                                         (long long)cur_isize,
1835                                         (long long)new_isize);
1836                 }
1837         } else {
1838                 nfsi->cache_validity |= save_cache_validity &
1839                                 (NFS_INO_INVALID_ATTR
1840                                 | NFS_INO_REVAL_PAGECACHE
1841                                 | NFS_INO_REVAL_FORCED);
1842                 cache_revalidated = false;
1843         }
1844 
1845 
1846         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1847                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1848         else if (server->caps & NFS_CAP_ATIME) {
1849                 nfsi->cache_validity |= save_cache_validity &
1850                                 (NFS_INO_INVALID_ATIME
1851                                 | NFS_INO_REVAL_FORCED);
1852                 cache_revalidated = false;
1853         }
1854 
1855         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1856                 if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1857                         umode_t newmode = inode->i_mode & S_IFMT;
1858                         newmode |= fattr->mode & S_IALLUGO;
1859                         inode->i_mode = newmode;
1860                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1861                 }
1862         } else if (server->caps & NFS_CAP_MODE) {
1863                 nfsi->cache_validity |= save_cache_validity &
1864                                 (NFS_INO_INVALID_ATTR
1865                                 | NFS_INO_INVALID_ACCESS
1866                                 | NFS_INO_INVALID_ACL
1867                                 | NFS_INO_REVAL_FORCED);
1868                 cache_revalidated = false;
1869         }
1870 
1871         if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1872                 if (!uid_eq(inode->i_uid, fattr->uid)) {
1873                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1874                         inode->i_uid = fattr->uid;
1875                 }
1876         } else if (server->caps & NFS_CAP_OWNER) {
1877                 nfsi->cache_validity |= save_cache_validity &
1878                                 (NFS_INO_INVALID_ATTR
1879                                 | NFS_INO_INVALID_ACCESS
1880                                 | NFS_INO_INVALID_ACL
1881                                 | NFS_INO_REVAL_FORCED);
1882                 cache_revalidated = false;
1883         }
1884 
1885         if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1886                 if (!gid_eq(inode->i_gid, fattr->gid)) {
1887                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1888                         inode->i_gid = fattr->gid;
1889                 }
1890         } else if (server->caps & NFS_CAP_OWNER_GROUP) {
1891                 nfsi->cache_validity |= save_cache_validity &
1892                                 (NFS_INO_INVALID_ATTR
1893                                 | NFS_INO_INVALID_ACCESS
1894                                 | NFS_INO_INVALID_ACL
1895                                 | NFS_INO_REVAL_FORCED);
1896                 cache_revalidated = false;
1897         }
1898 
1899         if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1900                 if (inode->i_nlink != fattr->nlink) {
1901                         invalid |= NFS_INO_INVALID_ATTR;
1902                         if (S_ISDIR(inode->i_mode))
1903                                 invalid |= NFS_INO_INVALID_DATA;
1904                         set_nlink(inode, fattr->nlink);
1905                 }
1906         } else if (server->caps & NFS_CAP_NLINK) {
1907                 nfsi->cache_validity |= save_cache_validity &
1908                                 (NFS_INO_INVALID_ATTR
1909                                 | NFS_INO_REVAL_FORCED);
1910                 cache_revalidated = false;
1911         }
1912 
1913         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1914                 /*
1915                  * report the blocks in 512byte units
1916                  */
1917                 inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1918         } else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1919                 inode->i_blocks = fattr->du.nfs2.blocks;
1920         else
1921                 cache_revalidated = false;
1922 
1923         /* Update attrtimeo value if we're out of the unstable period */
1924         if (invalid & NFS_INO_INVALID_ATTR) {
1925                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1926                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1927                 nfsi->attrtimeo_timestamp = now;
1928                 /* Set barrier to be more recent than all outstanding updates */
1929                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1930         } else {
1931                 if (cache_revalidated) {
1932                         if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
1933                                 nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1934                                 nfsi->attrtimeo <<= 1;
1935                                 if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
1936                                         nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1937                         }
1938                         nfsi->attrtimeo_timestamp = now;
1939                 }
1940                 /* Set the barrier to be more recent than this fattr */
1941                 if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
1942                         nfsi->attr_gencount = fattr->gencount;
1943         }
1944 
1945         /* Don't declare attrcache up to date if there were no attrs! */
1946         if (cache_revalidated)
1947                 invalid &= ~NFS_INO_INVALID_ATTR;
1948 
1949         /* Don't invalidate the data if we were to blame */
1950         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1951                                 || S_ISLNK(inode->i_mode)))
1952                 invalid &= ~NFS_INO_INVALID_DATA;
1953         if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1954                         (save_cache_validity & NFS_INO_REVAL_FORCED))
1955                 nfs_set_cache_invalid(inode, invalid);
1956 
1957         return 0;
1958  out_err:
1959         /*
1960          * No need to worry about unhashing the dentry, as the
1961          * lookup validation will know that the inode is bad.
1962          * (But we fall through to invalidate the caches.)
1963          */
1964         nfs_invalidate_inode(inode);
1965         return -ESTALE;
1966 }
1967 
1968 struct inode *nfs_alloc_inode(struct super_block *sb)
1969 {
1970         struct nfs_inode *nfsi;
1971         nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1972         if (!nfsi)
1973                 return NULL;
1974         nfsi->flags = 0UL;
1975         nfsi->cache_validity = 0UL;
1976 #if IS_ENABLED(CONFIG_NFS_V4)
1977         nfsi->nfs4_acl = NULL;
1978 #endif /* CONFIG_NFS_V4 */
1979         return &nfsi->vfs_inode;
1980 }
1981 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1982 
1983 static void nfs_i_callback(struct rcu_head *head)
1984 {
1985         struct inode *inode = container_of(head, struct inode, i_rcu);
1986         kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1987 }
1988 
1989 void nfs_destroy_inode(struct inode *inode)
1990 {
1991         call_rcu(&inode->i_rcu, nfs_i_callback);
1992 }
1993 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1994 
1995 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1996 {
1997 #if IS_ENABLED(CONFIG_NFS_V4)
1998         INIT_LIST_HEAD(&nfsi->open_states);
1999         nfsi->delegation = NULL;
2000         init_rwsem(&nfsi->rwsem);
2001         nfsi->layout = NULL;
2002 #endif
2003 }
2004 
2005 static void init_once(void *foo)
2006 {
2007         struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2008 
2009         inode_init_once(&nfsi->vfs_inode);
2010         INIT_LIST_HEAD(&nfsi->open_files);
2011         INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2012         INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2013         INIT_LIST_HEAD(&nfsi->commit_info.list);
2014         atomic_long_set(&nfsi->nrequests, 0);
2015         atomic_long_set(&nfsi->commit_info.ncommit, 0);
2016         atomic_set(&nfsi->commit_info.rpcs_out, 0);
2017         init_rwsem(&nfsi->rmdir_sem);
2018         mutex_init(&nfsi->commit_mutex);
2019         nfs4_init_once(nfsi);
2020 }
2021 
2022 static int __init nfs_init_inodecache(void)
2023 {
2024         nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2025                                              sizeof(struct nfs_inode),
2026                                              0, (SLAB_RECLAIM_ACCOUNT|
2027                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2028                                              init_once);
2029         if (nfs_inode_cachep == NULL)
2030                 return -ENOMEM;
2031 
2032         return 0;
2033 }
2034 
2035 static void nfs_destroy_inodecache(void)
2036 {
2037         /*
2038          * Make sure all delayed rcu free inodes are flushed before we
2039          * destroy cache.
2040          */
2041         rcu_barrier();
2042         kmem_cache_destroy(nfs_inode_cachep);
2043 }
2044 
2045 struct workqueue_struct *nfsiod_workqueue;
2046 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2047 
2048 /*
2049  * start up the nfsiod workqueue
2050  */
2051 static int nfsiod_start(void)
2052 {
2053         struct workqueue_struct *wq;
2054         dprintk("RPC:       creating workqueue nfsiod\n");
2055         wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2056         if (wq == NULL)
2057                 return -ENOMEM;
2058         nfsiod_workqueue = wq;
2059         return 0;
2060 }
2061 
2062 /*
2063  * Destroy the nfsiod workqueue
2064  */
2065 static void nfsiod_stop(void)
2066 {
2067         struct workqueue_struct *wq;
2068 
2069         wq = nfsiod_workqueue;
2070         if (wq == NULL)
2071                 return;
2072         nfsiod_workqueue = NULL;
2073         destroy_workqueue(wq);
2074 }
2075 
2076 unsigned int nfs_net_id;
2077 EXPORT_SYMBOL_GPL(nfs_net_id);
2078 
2079 static int nfs_net_init(struct net *net)
2080 {
2081         nfs_clients_init(net);
2082         return nfs_fs_proc_net_init(net);
2083 }
2084 
2085 static void nfs_net_exit(struct net *net)
2086 {
2087         struct nfs_net *nn = net_generic(net, nfs_net_id);
2088 
2089         nfs_fs_proc_net_exit(net);
2090         nfs_cleanup_cb_ident_idr(net);
2091         WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
2092         WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
2093 }
2094 
2095 static struct pernet_operations nfs_net_ops = {
2096         .init = nfs_net_init,
2097         .exit = nfs_net_exit,
2098         .id   = &nfs_net_id,
2099         .size = sizeof(struct nfs_net),
2100 };
2101 
2102 /*
2103  * Initialize NFS
2104  */
2105 static int __init init_nfs_fs(void)
2106 {
2107         int err;
2108 
2109         err = register_pernet_subsys(&nfs_net_ops);
2110         if (err < 0)
2111                 goto out9;
2112 
2113         err = nfs_fscache_register();
2114         if (err < 0)
2115                 goto out8;
2116 
2117         err = nfsiod_start();
2118         if (err)
2119                 goto out7;
2120 
2121         err = nfs_fs_proc_init();
2122         if (err)
2123                 goto out6;
2124 
2125         err = nfs_init_nfspagecache();
2126         if (err)
2127                 goto out5;
2128 
2129         err = nfs_init_inodecache();
2130         if (err)
2131                 goto out4;
2132 
2133         err = nfs_init_readpagecache();
2134         if (err)
2135                 goto out3;
2136 
2137         err = nfs_init_writepagecache();
2138         if (err)
2139                 goto out2;
2140 
2141         err = nfs_init_directcache();
2142         if (err)
2143                 goto out1;
2144 
2145         rpc_proc_register(&init_net, &nfs_rpcstat);
2146 
2147         err = register_nfs_fs();
2148         if (err)
2149                 goto out0;
2150 
2151         return 0;
2152 out0:
2153         rpc_proc_unregister(&init_net, "nfs");
2154         nfs_destroy_directcache();
2155 out1:
2156         nfs_destroy_writepagecache();
2157 out2:
2158         nfs_destroy_readpagecache();
2159 out3:
2160         nfs_destroy_inodecache();
2161 out4:
2162         nfs_destroy_nfspagecache();
2163 out5:
2164         nfs_fs_proc_exit();
2165 out6:
2166         nfsiod_stop();
2167 out7:
2168         nfs_fscache_unregister();
2169 out8:
2170         unregister_pernet_subsys(&nfs_net_ops);
2171 out9:
2172         return err;
2173 }
2174 
2175 static void __exit exit_nfs_fs(void)
2176 {
2177         nfs_destroy_directcache();
2178         nfs_destroy_writepagecache();
2179         nfs_destroy_readpagecache();
2180         nfs_destroy_inodecache();
2181         nfs_destroy_nfspagecache();
2182         nfs_fscache_unregister();
2183         unregister_pernet_subsys(&nfs_net_ops);
2184         rpc_proc_unregister(&init_net, "nfs");
2185         unregister_nfs_fs();
2186         nfs_fs_proc_exit();
2187         nfsiod_stop();
2188 }
2189 
2190 /* Not quite true; I just maintain it */
2191 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2192 MODULE_LICENSE("GPL");
2193 module_param(enable_ino64, bool, 0644);
2194 
2195 module_init(init_nfs_fs)
2196 module_exit(exit_nfs_fs)
2197 

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