Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/fs/nfs/inode.c

  1 /*
  2  *  linux/fs/nfs/inode.c
  3  *
  4  *  Copyright (C) 1992  Rick Sladkey
  5  *
  6  *  nfs inode and superblock handling functions
  7  *
  8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
  9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
 10  *
 11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
 12  *  J.S.Peatfield@damtp.cam.ac.uk
 13  *
 14  */
 15 
 16 #include <linux/module.h>
 17 #include <linux/init.h>
 18 #include <linux/sched.h>
 19 #include <linux/time.h>
 20 #include <linux/kernel.h>
 21 #include <linux/mm.h>
 22 #include <linux/string.h>
 23 #include <linux/stat.h>
 24 #include <linux/errno.h>
 25 #include <linux/unistd.h>
 26 #include <linux/sunrpc/clnt.h>
 27 #include <linux/sunrpc/stats.h>
 28 #include <linux/sunrpc/metrics.h>
 29 #include <linux/nfs_fs.h>
 30 #include <linux/nfs_mount.h>
 31 #include <linux/nfs4_mount.h>
 32 #include <linux/lockd/bind.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/mount.h>
 35 #include <linux/vfs.h>
 36 #include <linux/inet.h>
 37 #include <linux/nfs_xdr.h>
 38 #include <linux/slab.h>
 39 #include <linux/compat.h>
 40 #include <linux/freezer.h>
 41 
 42 #include <asm/uaccess.h>
 43 
 44 #include "nfs4_fs.h"
 45 #include "callback.h"
 46 #include "delegation.h"
 47 #include "iostat.h"
 48 #include "internal.h"
 49 #include "fscache.h"
 50 #include "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 void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
164 {
165         struct nfs_inode *nfsi = NFS_I(inode);
166 
167         if (inode->i_mapping->nrpages == 0)
168                 flags &= ~NFS_INO_INVALID_DATA;
169         nfsi->cache_validity |= flags;
170         if (flags & NFS_INO_INVALID_DATA)
171                 nfs_fscache_invalidate(inode);
172 }
173 
174 /*
175  * Invalidate the local caches
176  */
177 static void nfs_zap_caches_locked(struct inode *inode)
178 {
179         struct nfs_inode *nfsi = NFS_I(inode);
180         int mode = inode->i_mode;
181 
182         nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
183 
184         nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
185         nfsi->attrtimeo_timestamp = jiffies;
186 
187         memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
188         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
189                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
190                                         | NFS_INO_INVALID_DATA
191                                         | NFS_INO_INVALID_ACCESS
192                                         | NFS_INO_INVALID_ACL
193                                         | NFS_INO_REVAL_PAGECACHE);
194         } else
195                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
196                                         | NFS_INO_INVALID_ACCESS
197                                         | NFS_INO_INVALID_ACL
198                                         | NFS_INO_REVAL_PAGECACHE);
199         nfs_zap_label_cache_locked(nfsi);
200 }
201 
202 void nfs_zap_caches(struct inode *inode)
203 {
204         spin_lock(&inode->i_lock);
205         nfs_zap_caches_locked(inode);
206         spin_unlock(&inode->i_lock);
207 }
208 
209 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
210 {
211         if (mapping->nrpages != 0) {
212                 spin_lock(&inode->i_lock);
213                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
214                 spin_unlock(&inode->i_lock);
215         }
216 }
217 
218 void nfs_zap_acl_cache(struct inode *inode)
219 {
220         void (*clear_acl_cache)(struct inode *);
221 
222         clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
223         if (clear_acl_cache != NULL)
224                 clear_acl_cache(inode);
225         spin_lock(&inode->i_lock);
226         NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
227         spin_unlock(&inode->i_lock);
228 }
229 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
230 
231 void nfs_invalidate_atime(struct inode *inode)
232 {
233         spin_lock(&inode->i_lock);
234         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
235         spin_unlock(&inode->i_lock);
236 }
237 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
238 
239 /*
240  * Invalidate, but do not unhash, the inode.
241  * NB: must be called with inode->i_lock held!
242  */
243 static void nfs_invalidate_inode(struct inode *inode)
244 {
245         set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
246         nfs_zap_caches_locked(inode);
247 }
248 
249 struct nfs_find_desc {
250         struct nfs_fh           *fh;
251         struct nfs_fattr        *fattr;
252 };
253 
254 /*
255  * In NFSv3 we can have 64bit inode numbers. In order to support
256  * this, and re-exported directories (also seen in NFSv2)
257  * we are forced to allow 2 different inodes to have the same
258  * i_ino.
259  */
260 static int
261 nfs_find_actor(struct inode *inode, void *opaque)
262 {
263         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
264         struct nfs_fh           *fh = desc->fh;
265         struct nfs_fattr        *fattr = desc->fattr;
266 
267         if (NFS_FILEID(inode) != fattr->fileid)
268                 return 0;
269         if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
270                 return 0;
271         if (nfs_compare_fh(NFS_FH(inode), fh))
272                 return 0;
273         if (is_bad_inode(inode) || NFS_STALE(inode))
274                 return 0;
275         return 1;
276 }
277 
278 static int
279 nfs_init_locked(struct inode *inode, void *opaque)
280 {
281         struct nfs_find_desc    *desc = (struct nfs_find_desc *)opaque;
282         struct nfs_fattr        *fattr = desc->fattr;
283 
284         set_nfs_fileid(inode, fattr->fileid);
285         inode->i_mode = fattr->mode;
286         nfs_copy_fh(NFS_FH(inode), desc->fh);
287         return 0;
288 }
289 
290 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
291 static void nfs_clear_label_invalid(struct inode *inode)
292 {
293         spin_lock(&inode->i_lock);
294         NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
295         spin_unlock(&inode->i_lock);
296 }
297 
298 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
299                                         struct nfs4_label *label)
300 {
301         int error;
302 
303         if (label == NULL)
304                 return;
305 
306         if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
307                 error = security_inode_notifysecctx(inode, label->label,
308                                 label->len);
309                 if (error)
310                         printk(KERN_ERR "%s() %s %d "
311                                         "security_inode_notifysecctx() %d\n",
312                                         __func__,
313                                         (char *)label->label,
314                                         label->len, error);
315                 nfs_clear_label_invalid(inode);
316         }
317 }
318 
319 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
320 {
321         struct nfs4_label *label = NULL;
322         int minor_version = server->nfs_client->cl_minorversion;
323 
324         if (minor_version < 2)
325                 return label;
326 
327         if (!(server->caps & NFS_CAP_SECURITY_LABEL))
328                 return label;
329 
330         label = kzalloc(sizeof(struct nfs4_label), flags);
331         if (label == NULL)
332                 return ERR_PTR(-ENOMEM);
333 
334         label->label = kzalloc(NFS4_MAXLABELLEN, flags);
335         if (label->label == NULL) {
336                 kfree(label);
337                 return ERR_PTR(-ENOMEM);
338         }
339         label->len = NFS4_MAXLABELLEN;
340 
341         return label;
342 }
343 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
344 #else
345 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
346                                         struct nfs4_label *label)
347 {
348 }
349 #endif
350 EXPORT_SYMBOL_GPL(nfs_setsecurity);
351 
352 /*
353  * This is our front-end to iget that looks up inodes by file handle
354  * instead of inode number.
355  */
356 struct inode *
357 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
358 {
359         struct nfs_find_desc desc = {
360                 .fh     = fh,
361                 .fattr  = fattr
362         };
363         struct inode *inode = ERR_PTR(-ENOENT);
364         unsigned long hash;
365 
366         nfs_attr_check_mountpoint(sb, fattr);
367 
368         if (nfs_attr_use_mounted_on_fileid(fattr))
369                 fattr->fileid = fattr->mounted_on_fileid;
370         else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
371                 goto out_no_inode;
372         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
373                 goto out_no_inode;
374 
375         hash = nfs_fattr_to_ino_t(fattr);
376 
377         inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
378         if (inode == NULL) {
379                 inode = ERR_PTR(-ENOMEM);
380                 goto out_no_inode;
381         }
382 
383         if (inode->i_state & I_NEW) {
384                 struct nfs_inode *nfsi = NFS_I(inode);
385                 unsigned long now = jiffies;
386 
387                 /* We set i_ino for the few things that still rely on it,
388                  * such as stat(2) */
389                 inode->i_ino = hash;
390 
391                 /* We can't support update_atime(), since the server will reset it */
392                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
393                 inode->i_mode = fattr->mode;
394                 if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
395                                 && nfs_server_capable(inode, NFS_CAP_MODE))
396                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
397                 /* Why so? Because we want revalidate for devices/FIFOs, and
398                  * that's precisely what we have in nfs_file_inode_operations.
399                  */
400                 inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
401                 if (S_ISREG(inode->i_mode)) {
402                         inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
403                         inode->i_data.a_ops = &nfs_file_aops;
404                 } else if (S_ISDIR(inode->i_mode)) {
405                         inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
406                         inode->i_fop = &nfs_dir_operations;
407                         inode->i_data.a_ops = &nfs_dir_aops;
408                         /* Deal with crossing mountpoints */
409                         if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
410                                         fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
411                                 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
412                                         inode->i_op = &nfs_referral_inode_operations;
413                                 else
414                                         inode->i_op = &nfs_mountpoint_inode_operations;
415                                 inode->i_fop = NULL;
416                                 inode->i_flags |= S_AUTOMOUNT;
417                         }
418                 } else if (S_ISLNK(inode->i_mode)) {
419                         inode->i_op = &nfs_symlink_inode_operations;
420                         inode_nohighmem(inode);
421                 } else
422                         init_special_inode(inode, inode->i_mode, fattr->rdev);
423 
424                 memset(&inode->i_atime, 0, sizeof(inode->i_atime));
425                 memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
426                 memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
427                 inode->i_version = 0;
428                 inode->i_size = 0;
429                 clear_nlink(inode);
430                 inode->i_uid = make_kuid(&init_user_ns, -2);
431                 inode->i_gid = make_kgid(&init_user_ns, -2);
432                 inode->i_blocks = 0;
433                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
434                 nfsi->write_io = 0;
435                 nfsi->read_io = 0;
436 
437                 nfsi->read_cache_jiffies = fattr->time_start;
438                 nfsi->attr_gencount = fattr->gencount;
439                 if (fattr->valid & NFS_ATTR_FATTR_ATIME)
440                         inode->i_atime = fattr->atime;
441                 else if (nfs_server_capable(inode, NFS_CAP_ATIME))
442                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
443                 if (fattr->valid & NFS_ATTR_FATTR_MTIME)
444                         inode->i_mtime = fattr->mtime;
445                 else if (nfs_server_capable(inode, NFS_CAP_MTIME))
446                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
447                 if (fattr->valid & NFS_ATTR_FATTR_CTIME)
448                         inode->i_ctime = fattr->ctime;
449                 else if (nfs_server_capable(inode, NFS_CAP_CTIME))
450                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
451                 if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
452                         inode->i_version = fattr->change_attr;
453                 else
454                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
455                                 | NFS_INO_REVAL_PAGECACHE);
456                 if (fattr->valid & NFS_ATTR_FATTR_SIZE)
457                         inode->i_size = nfs_size_to_loff_t(fattr->size);
458                 else
459                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
460                                 | NFS_INO_REVAL_PAGECACHE);
461                 if (fattr->valid & NFS_ATTR_FATTR_NLINK)
462                         set_nlink(inode, fattr->nlink);
463                 else if (nfs_server_capable(inode, NFS_CAP_NLINK))
464                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
465                 if (fattr->valid & NFS_ATTR_FATTR_OWNER)
466                         inode->i_uid = fattr->uid;
467                 else if (nfs_server_capable(inode, NFS_CAP_OWNER))
468                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
469                 if (fattr->valid & NFS_ATTR_FATTR_GROUP)
470                         inode->i_gid = fattr->gid;
471                 else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
472                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
473                 if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
474                         inode->i_blocks = fattr->du.nfs2.blocks;
475                 if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
476                         /*
477                          * report the blocks in 512byte units
478                          */
479                         inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
480                 }
481 
482                 nfs_setsecurity(inode, fattr, label);
483 
484                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
485                 nfsi->attrtimeo_timestamp = now;
486                 nfsi->access_cache = RB_ROOT;
487 
488                 nfs_fscache_init_inode(inode);
489 
490                 unlock_new_inode(inode);
491         } else
492                 nfs_refresh_inode(inode, fattr);
493         dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
494                 inode->i_sb->s_id,
495                 (unsigned long long)NFS_FILEID(inode),
496                 nfs_display_fhandle_hash(fh),
497                 atomic_read(&inode->i_count));
498 
499 out:
500         return inode;
501 
502 out_no_inode:
503         dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
504         goto out;
505 }
506 EXPORT_SYMBOL_GPL(nfs_fhget);
507 
508 #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)
509 
510 int
511 nfs_setattr(struct dentry *dentry, struct iattr *attr)
512 {
513         struct inode *inode = d_inode(dentry);
514         struct nfs_fattr *fattr;
515         int error = 0;
516 
517         nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
518 
519         /* skip mode change if it's just for clearing setuid/setgid */
520         if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
521                 attr->ia_valid &= ~ATTR_MODE;
522 
523         if (attr->ia_valid & ATTR_SIZE) {
524                 BUG_ON(!S_ISREG(inode->i_mode));
525 
526                 error = inode_newsize_ok(inode, attr->ia_size);
527                 if (error)
528                         return error;
529 
530                 if (attr->ia_size == i_size_read(inode))
531                         attr->ia_valid &= ~ATTR_SIZE;
532         }
533 
534         /* Optimization: if the end result is no change, don't RPC */
535         attr->ia_valid &= NFS_VALID_ATTRS;
536         if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
537                 return 0;
538 
539         trace_nfs_setattr_enter(inode);
540 
541         /* Write all dirty data */
542         if (S_ISREG(inode->i_mode))
543                 nfs_sync_inode(inode);
544 
545         fattr = nfs_alloc_fattr();
546         if (fattr == NULL) {
547                 error = -ENOMEM;
548                 goto out;
549         }
550 
551         /*
552          * Return any delegations if we're going to change ACLs
553          */
554         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
555                 NFS_PROTO(inode)->return_delegation(inode);
556         error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
557         if (error == 0)
558                 error = nfs_refresh_inode(inode, fattr);
559         nfs_free_fattr(fattr);
560 out:
561         trace_nfs_setattr_exit(inode, error);
562         return error;
563 }
564 EXPORT_SYMBOL_GPL(nfs_setattr);
565 
566 /**
567  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
568  * @inode: inode of the file used
569  * @offset: file offset to start truncating
570  *
571  * This is a copy of the common vmtruncate, but with the locking
572  * corrected to take into account the fact that NFS requires
573  * inode->i_size to be updated under the inode->i_lock.
574  * Note: must be called with inode->i_lock held!
575  */
576 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
577 {
578         int err;
579 
580         err = inode_newsize_ok(inode, offset);
581         if (err)
582                 goto out;
583 
584         i_size_write(inode, offset);
585         /* Optimisation */
586         if (offset == 0)
587                 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
588 
589         spin_unlock(&inode->i_lock);
590         truncate_pagecache(inode, offset);
591         spin_lock(&inode->i_lock);
592 out:
593         return err;
594 }
595 
596 /**
597  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
598  * @inode: pointer to struct inode
599  * @attr: pointer to struct iattr
600  *
601  * Note: we do this in the *proc.c in order to ensure that
602  *       it works for things like exclusive creates too.
603  */
604 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
605                 struct nfs_fattr *fattr)
606 {
607         /* Barrier: bump the attribute generation count. */
608         nfs_fattr_set_barrier(fattr);
609 
610         spin_lock(&inode->i_lock);
611         NFS_I(inode)->attr_gencount = fattr->gencount;
612         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
613                 if ((attr->ia_valid & ATTR_MODE) != 0) {
614                         int mode = attr->ia_mode & S_IALLUGO;
615                         mode |= inode->i_mode & ~S_IALLUGO;
616                         inode->i_mode = mode;
617                 }
618                 if ((attr->ia_valid & ATTR_UID) != 0)
619                         inode->i_uid = attr->ia_uid;
620                 if ((attr->ia_valid & ATTR_GID) != 0)
621                         inode->i_gid = attr->ia_gid;
622                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
623                                 | NFS_INO_INVALID_ACL);
624         }
625         if ((attr->ia_valid & ATTR_SIZE) != 0) {
626                 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
627                 nfs_vmtruncate(inode, attr->ia_size);
628         }
629         if (fattr->valid)
630                 nfs_update_inode(inode, fattr);
631         else
632                 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
633         spin_unlock(&inode->i_lock);
634 }
635 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
636 
637 static void nfs_request_parent_use_readdirplus(struct dentry *dentry)
638 {
639         struct dentry *parent;
640 
641         parent = dget_parent(dentry);
642         nfs_force_use_readdirplus(d_inode(parent));
643         dput(parent);
644 }
645 
646 static bool nfs_need_revalidate_inode(struct inode *inode)
647 {
648         if (NFS_I(inode)->cache_validity &
649                         (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
650                 return true;
651         if (nfs_attribute_cache_expired(inode))
652                 return true;
653         return false;
654 }
655 
656 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
657 {
658         struct inode *inode = d_inode(dentry);
659         int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
660         int err = 0;
661 
662         trace_nfs_getattr_enter(inode);
663         /* Flush out writes to the server in order to update c/mtime.  */
664         if (S_ISREG(inode->i_mode)) {
665                 err = filemap_write_and_wait(inode->i_mapping);
666                 if (err)
667                         goto out;
668         }
669 
670         /*
671          * We may force a getattr if the user cares about atime.
672          *
673          * Note that we only have to check the vfsmount flags here:
674          *  - NFS always sets S_NOATIME by so checking it would give a
675          *    bogus result
676          *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
677          *    no point in checking those.
678          */
679         if ((mnt->mnt_flags & MNT_NOATIME) ||
680             ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
681                 need_atime = 0;
682 
683         if (need_atime || nfs_need_revalidate_inode(inode)) {
684                 struct nfs_server *server = NFS_SERVER(inode);
685 
686                 if (server->caps & NFS_CAP_READDIRPLUS)
687                         nfs_request_parent_use_readdirplus(dentry);
688                 err = __nfs_revalidate_inode(server, inode);
689         }
690         if (!err) {
691                 generic_fillattr(inode, stat);
692                 stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
693                 if (S_ISDIR(inode->i_mode))
694                         stat->blksize = NFS_SERVER(inode)->dtsize;
695         }
696 out:
697         trace_nfs_getattr_exit(inode, err);
698         return err;
699 }
700 EXPORT_SYMBOL_GPL(nfs_getattr);
701 
702 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
703 {
704         atomic_set(&l_ctx->count, 1);
705         l_ctx->lockowner.l_owner = current->files;
706         l_ctx->lockowner.l_pid = current->tgid;
707         INIT_LIST_HEAD(&l_ctx->list);
708         atomic_set(&l_ctx->io_count, 0);
709 }
710 
711 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
712 {
713         struct nfs_lock_context *head = &ctx->lock_context;
714         struct nfs_lock_context *pos = head;
715 
716         do {
717                 if (pos->lockowner.l_owner != current->files)
718                         continue;
719                 if (pos->lockowner.l_pid != current->tgid)
720                         continue;
721                 atomic_inc(&pos->count);
722                 return pos;
723         } while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
724         return NULL;
725 }
726 
727 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
728 {
729         struct nfs_lock_context *res, *new = NULL;
730         struct inode *inode = d_inode(ctx->dentry);
731 
732         spin_lock(&inode->i_lock);
733         res = __nfs_find_lock_context(ctx);
734         if (res == NULL) {
735                 spin_unlock(&inode->i_lock);
736                 new = kmalloc(sizeof(*new), GFP_KERNEL);
737                 if (new == NULL)
738                         return ERR_PTR(-ENOMEM);
739                 nfs_init_lock_context(new);
740                 spin_lock(&inode->i_lock);
741                 res = __nfs_find_lock_context(ctx);
742                 if (res == NULL) {
743                         list_add_tail(&new->list, &ctx->lock_context.list);
744                         new->open_context = ctx;
745                         res = new;
746                         new = NULL;
747                 }
748         }
749         spin_unlock(&inode->i_lock);
750         kfree(new);
751         return res;
752 }
753 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
754 
755 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
756 {
757         struct nfs_open_context *ctx = l_ctx->open_context;
758         struct inode *inode = d_inode(ctx->dentry);
759 
760         if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
761                 return;
762         list_del(&l_ctx->list);
763         spin_unlock(&inode->i_lock);
764         kfree(l_ctx);
765 }
766 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
767 
768 /**
769  * nfs_close_context - Common close_context() routine NFSv2/v3
770  * @ctx: pointer to context
771  * @is_sync: is this a synchronous close
772  *
773  * Ensure that the attributes are up to date if we're mounted
774  * with close-to-open semantics and we have cached data that will
775  * need to be revalidated on open.
776  */
777 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
778 {
779         struct nfs_inode *nfsi;
780         struct inode *inode;
781         struct nfs_server *server;
782 
783         if (!(ctx->mode & FMODE_WRITE))
784                 return;
785         if (!is_sync)
786                 return;
787         inode = d_inode(ctx->dentry);
788         nfsi = NFS_I(inode);
789         if (inode->i_mapping->nrpages == 0)
790                 return;
791         if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
792                 return;
793         if (!list_empty(&nfsi->open_files))
794                 return;
795         server = NFS_SERVER(inode);
796         if (server->flags & NFS_MOUNT_NOCTO)
797                 return;
798         nfs_revalidate_inode(server, inode);
799 }
800 EXPORT_SYMBOL_GPL(nfs_close_context);
801 
802 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
803 {
804         struct nfs_open_context *ctx;
805         struct rpc_cred *cred = rpc_lookup_cred();
806         if (IS_ERR(cred))
807                 return ERR_CAST(cred);
808 
809         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
810         if (!ctx) {
811                 put_rpccred(cred);
812                 return ERR_PTR(-ENOMEM);
813         }
814         nfs_sb_active(dentry->d_sb);
815         ctx->dentry = dget(dentry);
816         ctx->cred = cred;
817         ctx->state = NULL;
818         ctx->mode = f_mode;
819         ctx->flags = 0;
820         ctx->error = 0;
821         nfs_init_lock_context(&ctx->lock_context);
822         ctx->lock_context.open_context = ctx;
823         INIT_LIST_HEAD(&ctx->list);
824         ctx->mdsthreshold = NULL;
825         return ctx;
826 }
827 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
828 
829 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
830 {
831         if (ctx != NULL)
832                 atomic_inc(&ctx->lock_context.count);
833         return ctx;
834 }
835 EXPORT_SYMBOL_GPL(get_nfs_open_context);
836 
837 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
838 {
839         struct inode *inode = d_inode(ctx->dentry);
840         struct super_block *sb = ctx->dentry->d_sb;
841 
842         if (!list_empty(&ctx->list)) {
843                 if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
844                         return;
845                 list_del(&ctx->list);
846                 spin_unlock(&inode->i_lock);
847         } else if (!atomic_dec_and_test(&ctx->lock_context.count))
848                 return;
849         if (inode != NULL)
850                 NFS_PROTO(inode)->close_context(ctx, is_sync);
851         if (ctx->cred != NULL)
852                 put_rpccred(ctx->cred);
853         dput(ctx->dentry);
854         nfs_sb_deactive(sb);
855         kfree(ctx->mdsthreshold);
856         kfree(ctx);
857 }
858 
859 void put_nfs_open_context(struct nfs_open_context *ctx)
860 {
861         __put_nfs_open_context(ctx, 0);
862 }
863 EXPORT_SYMBOL_GPL(put_nfs_open_context);
864 
865 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
866 {
867         __put_nfs_open_context(ctx, 1);
868 }
869 
870 /*
871  * Ensure that mmap has a recent RPC credential for use when writing out
872  * shared pages
873  */
874 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
875 {
876         struct inode *inode = d_inode(ctx->dentry);
877         struct nfs_inode *nfsi = NFS_I(inode);
878 
879         spin_lock(&inode->i_lock);
880         if (ctx->mode & FMODE_WRITE)
881                 list_add(&ctx->list, &nfsi->open_files);
882         else
883                 list_add_tail(&ctx->list, &nfsi->open_files);
884         spin_unlock(&inode->i_lock);
885 }
886 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
887 
888 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
889 {
890         filp->private_data = get_nfs_open_context(ctx);
891         if (list_empty(&ctx->list))
892                 nfs_inode_attach_open_context(ctx);
893 }
894 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
895 
896 /*
897  * Given an inode, search for an open context with the desired characteristics
898  */
899 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
900 {
901         struct nfs_inode *nfsi = NFS_I(inode);
902         struct nfs_open_context *pos, *ctx = NULL;
903 
904         spin_lock(&inode->i_lock);
905         list_for_each_entry(pos, &nfsi->open_files, list) {
906                 if (cred != NULL && pos->cred != cred)
907                         continue;
908                 if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
909                         continue;
910                 ctx = get_nfs_open_context(pos);
911                 break;
912         }
913         spin_unlock(&inode->i_lock);
914         return ctx;
915 }
916 
917 void nfs_file_clear_open_context(struct file *filp)
918 {
919         struct nfs_open_context *ctx = nfs_file_open_context(filp);
920 
921         if (ctx) {
922                 struct inode *inode = d_inode(ctx->dentry);
923 
924                 /*
925                  * We fatal error on write before. Try to writeback
926                  * every page again.
927                  */
928                 if (ctx->error < 0)
929                         invalidate_inode_pages2(inode->i_mapping);
930                 filp->private_data = NULL;
931                 spin_lock(&inode->i_lock);
932                 list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
933                 spin_unlock(&inode->i_lock);
934                 put_nfs_open_context_sync(ctx);
935         }
936 }
937 
938 /*
939  * These allocate and release file read/write context information.
940  */
941 int nfs_open(struct inode *inode, struct file *filp)
942 {
943         struct nfs_open_context *ctx;
944 
945         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode);
946         if (IS_ERR(ctx))
947                 return PTR_ERR(ctx);
948         nfs_file_set_open_context(filp, ctx);
949         put_nfs_open_context(ctx);
950         nfs_fscache_open_file(inode, filp);
951         return 0;
952 }
953 
954 /*
955  * This function is called whenever some part of NFS notices that
956  * the cached attributes have to be refreshed.
957  */
958 int
959 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
960 {
961         int              status = -ESTALE;
962         struct nfs4_label *label = NULL;
963         struct nfs_fattr *fattr = NULL;
964         struct nfs_inode *nfsi = NFS_I(inode);
965 
966         dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
967                 inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
968 
969         trace_nfs_revalidate_inode_enter(inode);
970 
971         if (is_bad_inode(inode))
972                 goto out;
973         if (NFS_STALE(inode))
974                 goto out;
975 
976         /* pNFS: Attributes aren't updated until we layoutcommit */
977         if (S_ISREG(inode->i_mode)) {
978                 status = pnfs_sync_inode(inode, false);
979                 if (status)
980                         goto out;
981         }
982 
983         status = -ENOMEM;
984         fattr = nfs_alloc_fattr();
985         if (fattr == NULL)
986                 goto out;
987 
988         nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
989 
990         label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
991         if (IS_ERR(label)) {
992                 status = PTR_ERR(label);
993                 goto out;
994         }
995 
996         status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, label);
997         if (status != 0) {
998                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
999                          inode->i_sb->s_id,
1000                          (unsigned long long)NFS_FILEID(inode), status);
1001                 if (status == -ESTALE) {
1002                         nfs_zap_caches(inode);
1003                         if (!S_ISDIR(inode->i_mode))
1004                                 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1005                 }
1006                 goto err_out;
1007         }
1008 
1009         status = nfs_refresh_inode(inode, fattr);
1010         if (status) {
1011                 dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1012                          inode->i_sb->s_id,
1013                          (unsigned long long)NFS_FILEID(inode), status);
1014                 goto err_out;
1015         }
1016 
1017         if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1018                 nfs_zap_acl_cache(inode);
1019 
1020         nfs_setsecurity(inode, fattr, label);
1021 
1022         dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1023                 inode->i_sb->s_id,
1024                 (unsigned long long)NFS_FILEID(inode));
1025 
1026 err_out:
1027         nfs4_label_free(label);
1028 out:
1029         nfs_free_fattr(fattr);
1030         trace_nfs_revalidate_inode_exit(inode, status);
1031         return status;
1032 }
1033 
1034 int nfs_attribute_timeout(struct inode *inode)
1035 {
1036         struct nfs_inode *nfsi = NFS_I(inode);
1037 
1038         return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
1039 }
1040 
1041 int nfs_attribute_cache_expired(struct inode *inode)
1042 {
1043         if (nfs_have_delegated_attributes(inode))
1044                 return 0;
1045         return nfs_attribute_timeout(inode);
1046 }
1047 
1048 /**
1049  * nfs_revalidate_inode - Revalidate the inode attributes
1050  * @server - pointer to nfs_server struct
1051  * @inode - pointer to inode struct
1052  *
1053  * Updates inode attribute information by retrieving the data from the server.
1054  */
1055 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1056 {
1057         if (!nfs_need_revalidate_inode(inode))
1058                 return NFS_STALE(inode) ? -ESTALE : 0;
1059         return __nfs_revalidate_inode(server, inode);
1060 }
1061 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1062 
1063 int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode)
1064 {
1065         if (!(NFS_I(inode)->cache_validity &
1066                         (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
1067                         && !nfs_attribute_cache_expired(inode))
1068                 return NFS_STALE(inode) ? -ESTALE : 0;
1069         return -ECHILD;
1070 }
1071 
1072 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1073 {
1074         struct nfs_inode *nfsi = NFS_I(inode);
1075         int ret;
1076 
1077         if (mapping->nrpages != 0) {
1078                 if (S_ISREG(inode->i_mode)) {
1079                         unmap_mapping_range(mapping, 0, 0, 0);
1080                         ret = nfs_sync_mapping(mapping);
1081                         if (ret < 0)
1082                                 return ret;
1083                 }
1084                 ret = invalidate_inode_pages2(mapping);
1085                 if (ret < 0)
1086                         return ret;
1087         }
1088         if (S_ISDIR(inode->i_mode)) {
1089                 spin_lock(&inode->i_lock);
1090                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1091                 spin_unlock(&inode->i_lock);
1092         }
1093         nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1094         nfs_fscache_wait_on_invalidate(inode);
1095 
1096         dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1097                         inode->i_sb->s_id,
1098                         (unsigned long long)NFS_FILEID(inode));
1099         return 0;
1100 }
1101 
1102 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1103 {
1104         if (nfs_have_delegated_attributes(inode))
1105                 return false;
1106         return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
1107                 || nfs_attribute_timeout(inode)
1108                 || NFS_STALE(inode);
1109 }
1110 
1111 int nfs_revalidate_mapping_rcu(struct inode *inode)
1112 {
1113         struct nfs_inode *nfsi = NFS_I(inode);
1114         unsigned long *bitlock = &nfsi->flags;
1115         int ret = 0;
1116 
1117         if (IS_SWAPFILE(inode))
1118                 goto out;
1119         if (nfs_mapping_need_revalidate_inode(inode)) {
1120                 ret = -ECHILD;
1121                 goto out;
1122         }
1123         spin_lock(&inode->i_lock);
1124         if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1125             (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1126                 ret = -ECHILD;
1127         spin_unlock(&inode->i_lock);
1128 out:
1129         return ret;
1130 }
1131 
1132 /**
1133  * nfs_revalidate_mapping - Revalidate the pagecache
1134  * @inode - pointer to host inode
1135  * @mapping - pointer to mapping
1136  */
1137 int nfs_revalidate_mapping(struct inode *inode,
1138                 struct address_space *mapping)
1139 {
1140         struct nfs_inode *nfsi = NFS_I(inode);
1141         unsigned long *bitlock = &nfsi->flags;
1142         int ret = 0;
1143 
1144         /* swapfiles are not supposed to be shared. */
1145         if (IS_SWAPFILE(inode))
1146                 goto out;
1147 
1148         if (nfs_mapping_need_revalidate_inode(inode)) {
1149                 ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1150                 if (ret < 0)
1151                         goto out;
1152         }
1153 
1154         /*
1155          * We must clear NFS_INO_INVALID_DATA first to ensure that
1156          * invalidations that come in while we're shooting down the mappings
1157          * are respected. But, that leaves a race window where one revalidator
1158          * can clear the flag, and then another checks it before the mapping
1159          * gets invalidated. Fix that by serializing access to this part of
1160          * the function.
1161          *
1162          * At the same time, we need to allow other tasks to see whether we
1163          * might be in the middle of invalidating the pages, so we only set
1164          * the bit lock here if it looks like we're going to be doing that.
1165          */
1166         for (;;) {
1167                 ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1168                                          nfs_wait_bit_killable, TASK_KILLABLE);
1169                 if (ret)
1170                         goto out;
1171                 spin_lock(&inode->i_lock);
1172                 if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1173                         spin_unlock(&inode->i_lock);
1174                         continue;
1175                 }
1176                 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1177                         break;
1178                 spin_unlock(&inode->i_lock);
1179                 goto out;
1180         }
1181 
1182         set_bit(NFS_INO_INVALIDATING, bitlock);
1183         smp_wmb();
1184         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1185         spin_unlock(&inode->i_lock);
1186         trace_nfs_invalidate_mapping_enter(inode);
1187         ret = nfs_invalidate_mapping(inode, mapping);
1188         trace_nfs_invalidate_mapping_exit(inode, ret);
1189 
1190         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1191         smp_mb__after_atomic();
1192         wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1193 out:
1194         return ret;
1195 }
1196 
1197 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1198 {
1199         struct inode *inode = &nfsi->vfs_inode;
1200 
1201         assert_spin_locked(&inode->i_lock);
1202 
1203         if (!S_ISREG(inode->i_mode))
1204                 return false;
1205         if (list_empty(&nfsi->open_files))
1206                 return false;
1207         /* Note: This relies on nfsi->open_files being ordered with writers
1208          *       being placed at the head of the list.
1209          *       See nfs_inode_attach_open_context()
1210          */
1211         return (list_first_entry(&nfsi->open_files,
1212                         struct nfs_open_context,
1213                         list)->mode & FMODE_WRITE) == FMODE_WRITE;
1214 }
1215 
1216 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1217 {
1218         return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1219 }
1220 
1221 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1222 {
1223         struct nfs_inode *nfsi = NFS_I(inode);
1224         unsigned long ret = 0;
1225 
1226         if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1227                         && (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1228                         && inode->i_version == fattr->pre_change_attr) {
1229                 inode->i_version = fattr->change_attr;
1230                 if (S_ISDIR(inode->i_mode))
1231                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1232                 ret |= NFS_INO_INVALID_ATTR;
1233         }
1234         /* If we have atomic WCC data, we may update some attributes */
1235         if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1236                         && (fattr->valid & NFS_ATTR_FATTR_CTIME)
1237                         && timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1238                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1239                 ret |= NFS_INO_INVALID_ATTR;
1240         }
1241 
1242         if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1243                         && (fattr->valid & NFS_ATTR_FATTR_MTIME)
1244                         && timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1245                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1246                 if (S_ISDIR(inode->i_mode))
1247                         nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1248                 ret |= NFS_INO_INVALID_ATTR;
1249         }
1250         if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1251                         && (fattr->valid & NFS_ATTR_FATTR_SIZE)
1252                         && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1253                         && nfsi->nrequests == 0) {
1254                 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1255                 ret |= NFS_INO_INVALID_ATTR;
1256         }
1257 
1258         return ret;
1259 }
1260 
1261 /**
1262  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1263  * @inode - pointer to inode
1264  * @fattr - updated attributes
1265  *
1266  * Verifies the attribute cache. If we have just changed the attributes,
1267  * so that fattr carries weak cache consistency data, then it may
1268  * also update the ctime/mtime/change_attribute.
1269  */
1270 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1271 {
1272         struct nfs_inode *nfsi = NFS_I(inode);
1273         loff_t cur_size, new_isize;
1274         unsigned long invalid = 0;
1275 
1276 
1277         if (nfs_have_delegated_attributes(inode))
1278                 return 0;
1279         /* Has the inode gone and changed behind our back? */
1280         if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1281                 return -EIO;
1282         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1283                 return -EIO;
1284 
1285         if (!nfs_file_has_buffered_writers(nfsi)) {
1286                 /* Verify a few of the more important attributes */
1287                 if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && inode->i_version != fattr->change_attr)
1288                         invalid |= NFS_INO_INVALID_ATTR | NFS_INO_REVAL_PAGECACHE;
1289 
1290                 if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1291                         invalid |= NFS_INO_INVALID_ATTR;
1292 
1293                 if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
1294                         invalid |= NFS_INO_INVALID_ATTR;
1295 
1296                 if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1297                         cur_size = i_size_read(inode);
1298                         new_isize = nfs_size_to_loff_t(fattr->size);
1299                         if (cur_size != new_isize)
1300                                 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1301                 }
1302         }
1303 
1304         /* Have any file permissions changed? */
1305         if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1306                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1307         if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1308                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1309         if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1310                 invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1311 
1312         /* Has the link count changed? */
1313         if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1314                 invalid |= NFS_INO_INVALID_ATTR;
1315 
1316         if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1317                 invalid |= NFS_INO_INVALID_ATIME;
1318 
1319         if (invalid != 0)
1320                 nfs_set_cache_invalid(inode, invalid);
1321 
1322         nfsi->read_cache_jiffies = fattr->time_start;
1323         return 0;
1324 }
1325 
1326 static atomic_long_t nfs_attr_generation_counter;
1327 
1328 static unsigned long nfs_read_attr_generation_counter(void)
1329 {
1330         return atomic_long_read(&nfs_attr_generation_counter);
1331 }
1332 
1333 unsigned long nfs_inc_attr_generation_counter(void)
1334 {
1335         return atomic_long_inc_return(&nfs_attr_generation_counter);
1336 }
1337 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1338 
1339 void nfs_fattr_init(struct nfs_fattr *fattr)
1340 {
1341         fattr->valid = 0;
1342         fattr->time_start = jiffies;
1343         fattr->gencount = nfs_inc_attr_generation_counter();
1344         fattr->owner_name = NULL;
1345         fattr->group_name = NULL;
1346 }
1347 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1348 
1349 /**
1350  * nfs_fattr_set_barrier
1351  * @fattr: attributes
1352  *
1353  * Used to set a barrier after an attribute was updated. This
1354  * barrier ensures that older attributes from RPC calls that may
1355  * have raced with our update cannot clobber these new values.
1356  * Note that you are still responsible for ensuring that other
1357  * operations which change the attribute on the server do not
1358  * collide.
1359  */
1360 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1361 {
1362         fattr->gencount = nfs_inc_attr_generation_counter();
1363 }
1364 
1365 struct nfs_fattr *nfs_alloc_fattr(void)
1366 {
1367         struct nfs_fattr *fattr;
1368 
1369         fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1370         if (fattr != NULL)
1371                 nfs_fattr_init(fattr);
1372         return fattr;
1373 }
1374 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1375 
1376 struct nfs_fh *nfs_alloc_fhandle(void)
1377 {
1378         struct nfs_fh *fh;
1379 
1380         fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1381         if (fh != NULL)
1382                 fh->size = 0;
1383         return fh;
1384 }
1385 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1386 
1387 #ifdef NFS_DEBUG
1388 /*
1389  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1390  *                             in the same way that wireshark does
1391  *
1392  * @fh: file handle
1393  *
1394  * For debugging only.
1395  */
1396 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1397 {
1398         /* wireshark uses 32-bit AUTODIN crc and does a bitwise
1399          * not on the result */
1400         return nfs_fhandle_hash(fh);
1401 }
1402 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1403 
1404 /*
1405  * _nfs_display_fhandle - display an NFS file handle on the console
1406  *
1407  * @fh: file handle to display
1408  * @caption: display caption
1409  *
1410  * For debugging only.
1411  */
1412 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1413 {
1414         unsigned short i;
1415 
1416         if (fh == NULL || fh->size == 0) {
1417                 printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1418                 return;
1419         }
1420 
1421         printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1422                caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1423         for (i = 0; i < fh->size; i += 16) {
1424                 __be32 *pos = (__be32 *)&fh->data[i];
1425 
1426                 switch ((fh->size - i - 1) >> 2) {
1427                 case 0:
1428                         printk(KERN_DEFAULT " %08x\n",
1429                                 be32_to_cpup(pos));
1430                         break;
1431                 case 1:
1432                         printk(KERN_DEFAULT " %08x %08x\n",
1433                                 be32_to_cpup(pos), be32_to_cpup(pos + 1));
1434                         break;
1435                 case 2:
1436                         printk(KERN_DEFAULT " %08x %08x %08x\n",
1437                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1438                                 be32_to_cpup(pos + 2));
1439                         break;
1440                 default:
1441                         printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1442                                 be32_to_cpup(pos), be32_to_cpup(pos + 1),
1443                                 be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1444                 }
1445         }
1446 }
1447 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1448 #endif
1449 
1450 /**
1451  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1452  * @inode - pointer to inode
1453  * @fattr - attributes
1454  *
1455  * Attempt to divine whether or not an RPC call reply carrying stale
1456  * attributes got scheduled after another call carrying updated ones.
1457  *
1458  * To do so, the function first assumes that a more recent ctime means
1459  * that the attributes in fattr are newer, however it also attempt to
1460  * catch the case where ctime either didn't change, or went backwards
1461  * (if someone reset the clock on the server) by looking at whether
1462  * or not this RPC call was started after the inode was last updated.
1463  * Note also the check for wraparound of 'attr_gencount'
1464  *
1465  * The function returns 'true' if it thinks the attributes in 'fattr' are
1466  * more recent than the ones cached in the inode.
1467  *
1468  */
1469 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1470 {
1471         const struct nfs_inode *nfsi = NFS_I(inode);
1472 
1473         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1474                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1475 }
1476 
1477 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1478 {
1479         int ret;
1480 
1481         trace_nfs_refresh_inode_enter(inode);
1482 
1483         if (nfs_inode_attrs_need_update(inode, fattr))
1484                 ret = nfs_update_inode(inode, fattr);
1485         else
1486                 ret = nfs_check_inode_attributes(inode, fattr);
1487 
1488         trace_nfs_refresh_inode_exit(inode, ret);
1489         return ret;
1490 }
1491 
1492 /**
1493  * nfs_refresh_inode - try to update the inode attribute cache
1494  * @inode - pointer to inode
1495  * @fattr - updated attributes
1496  *
1497  * Check that an RPC call that returned attributes has not overlapped with
1498  * other recent updates of the inode metadata, then decide whether it is
1499  * safe to do a full update of the inode attributes, or whether just to
1500  * call nfs_check_inode_attributes.
1501  */
1502 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1503 {
1504         int status;
1505 
1506         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1507                 return 0;
1508         spin_lock(&inode->i_lock);
1509         status = nfs_refresh_inode_locked(inode, fattr);
1510         spin_unlock(&inode->i_lock);
1511 
1512         return status;
1513 }
1514 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1515 
1516 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1517 {
1518         unsigned long invalid = NFS_INO_INVALID_ATTR;
1519 
1520         /*
1521          * Don't revalidate the pagecache if we hold a delegation, but do
1522          * force an attribute update
1523          */
1524         if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1525                 invalid = NFS_INO_INVALID_ATTR|NFS_INO_REVAL_FORCED;
1526 
1527         if (S_ISDIR(inode->i_mode))
1528                 invalid |= NFS_INO_INVALID_DATA;
1529         nfs_set_cache_invalid(inode, invalid);
1530         if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1531                 return 0;
1532         return nfs_refresh_inode_locked(inode, fattr);
1533 }
1534 
1535 /**
1536  * nfs_post_op_update_inode - try to update the inode attribute cache
1537  * @inode - pointer to inode
1538  * @fattr - updated attributes
1539  *
1540  * After an operation that has changed the inode metadata, mark the
1541  * attribute cache as being invalid, then try to update it.
1542  *
1543  * NB: if the server didn't return any post op attributes, this
1544  * function will force the retrieval of attributes before the next
1545  * NFS request.  Thus it should be used only for operations that
1546  * are expected to change one or more attributes, to avoid
1547  * unnecessary NFS requests and trips through nfs_update_inode().
1548  */
1549 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1550 {
1551         int status;
1552 
1553         spin_lock(&inode->i_lock);
1554         nfs_fattr_set_barrier(fattr);
1555         status = nfs_post_op_update_inode_locked(inode, fattr);
1556         spin_unlock(&inode->i_lock);
1557 
1558         return status;
1559 }
1560 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1561 
1562 /**
1563  * nfs_post_op_update_inode_force_wcc_locked - 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. Fake up
1569  * weak cache consistency data, if none exist.
1570  *
1571  * This function is mainly designed to be used by the ->write_done() functions.
1572  */
1573 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1574 {
1575         int status;
1576 
1577         /* Don't do a WCC update if these attributes are already stale */
1578         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1579                         !nfs_inode_attrs_need_update(inode, fattr)) {
1580                 fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1581                                 | NFS_ATTR_FATTR_PRESIZE
1582                                 | NFS_ATTR_FATTR_PREMTIME
1583                                 | NFS_ATTR_FATTR_PRECTIME);
1584                 goto out_noforce;
1585         }
1586         if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1587                         (fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1588                 fattr->pre_change_attr = inode->i_version;
1589                 fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1590         }
1591         if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1592                         (fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1593                 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1594                 fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1595         }
1596         if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1597                         (fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1598                 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1599                 fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1600         }
1601         if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1602                         (fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1603                 fattr->pre_size = i_size_read(inode);
1604                 fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1605         }
1606 out_noforce:
1607         status = nfs_post_op_update_inode_locked(inode, fattr);
1608         return status;
1609 }
1610 
1611 /**
1612  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1613  * @inode - pointer to inode
1614  * @fattr - updated attributes
1615  *
1616  * After an operation that has changed the inode metadata, mark the
1617  * attribute cache as being invalid, then try to update it. Fake up
1618  * weak cache consistency data, if none exist.
1619  *
1620  * This function is mainly designed to be used by the ->write_done() functions.
1621  */
1622 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1623 {
1624         int status;
1625 
1626         spin_lock(&inode->i_lock);
1627         nfs_fattr_set_barrier(fattr);
1628         status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1629         spin_unlock(&inode->i_lock);
1630         return status;
1631 }
1632 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1633 
1634 
1635 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1636                                     struct nfs_fattr *fattr)
1637 {
1638         bool ret1 = true, ret2 = true;
1639 
1640         if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1641                 ret1 = (nfsi->fileid == fattr->fileid);
1642         if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1643                 ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1644         return ret1 || ret2;
1645 }
1646 
1647 /*
1648  * Many nfs protocol calls return the new file attributes after
1649  * an operation.  Here we update the inode to reflect the state
1650  * of the server's inode.
1651  *
1652  * This is a bit tricky because we have to make sure all dirty pages
1653  * have been sent off to the server before calling invalidate_inode_pages.
1654  * To make sure no other process adds more write requests while we try
1655  * our best to flush them, we make them sleep during the attribute refresh.
1656  *
1657  * A very similar scenario holds for the dir cache.
1658  */
1659 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1660 {
1661         struct nfs_server *server;
1662         struct nfs_inode *nfsi = NFS_I(inode);
1663         loff_t cur_isize, new_isize;
1664         unsigned long invalid = 0;
1665         unsigned long now = jiffies;
1666         unsigned long save_cache_validity;
1667         bool have_writers = nfs_file_has_buffered_writers(nfsi);
1668         bool cache_revalidated = true;
1669 
1670         dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1671                         __func__, inode->i_sb->s_id, inode->i_ino,
1672                         nfs_display_fhandle_hash(NFS_FH(inode)),
1673                         atomic_read(&inode->i_count), fattr->valid);
1674 
1675         if (!nfs_fileid_valid(nfsi, fattr)) {
1676                 printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1677                         "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1678                         NFS_SERVER(inode)->nfs_client->cl_hostname,
1679                         inode->i_sb->s_id, (long long)nfsi->fileid,
1680                         (long long)fattr->fileid);
1681                 goto out_err;
1682         }
1683 
1684         /*
1685          * Make sure the inode's type hasn't changed.
1686          */
1687         if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1688                 /*
1689                 * Big trouble! The inode has become a different object.
1690                 */
1691                 printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1692                                 __func__, inode->i_ino, inode->i_mode, fattr->mode);
1693                 goto out_err;
1694         }
1695 
1696         server = NFS_SERVER(inode);
1697         /* Update the fsid? */
1698         if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1699                         !nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1700                         !IS_AUTOMOUNT(inode))
1701                 server->fsid = fattr->fsid;
1702 
1703         /*
1704          * Update the read time so we don't revalidate too often.
1705          */
1706         nfsi->read_cache_jiffies = fattr->time_start;
1707 
1708         save_cache_validity = nfsi->cache_validity;
1709         nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1710                         | NFS_INO_INVALID_ATIME
1711                         | NFS_INO_REVAL_FORCED
1712                         | NFS_INO_REVAL_PAGECACHE);
1713 
1714         /* Do atomic weak cache consistency updates */
1715         invalid |= nfs_wcc_update_inode(inode, fattr);
1716 
1717         if (pnfs_layoutcommit_outstanding(inode)) {
1718                 nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1719                 cache_revalidated = false;
1720         }
1721 
1722         /* More cache consistency checks */
1723         if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1724                 if (inode->i_version != fattr->change_attr) {
1725                         dprintk("NFS: change_attr change on server for file %s/%ld\n",
1726                                         inode->i_sb->s_id, inode->i_ino);
1727                         /* Could it be a race with writeback? */
1728                         if (!have_writers) {
1729                                 invalid |= NFS_INO_INVALID_ATTR
1730                                         | NFS_INO_INVALID_DATA
1731                                         | NFS_INO_INVALID_ACCESS
1732                                         | NFS_INO_INVALID_ACL;
1733                                 if (S_ISDIR(inode->i_mode))
1734                                         nfs_force_lookup_revalidate(inode);
1735                         }
1736                         inode->i_version = fattr->change_attr;
1737                 }
1738         } else {
1739                 nfsi->cache_validity |= save_cache_validity;
1740                 cache_revalidated = false;
1741         }
1742 
1743         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1744                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1745         } else if (server->caps & NFS_CAP_MTIME) {
1746                 nfsi->cache_validity |= save_cache_validity &
1747                                 (NFS_INO_INVALID_ATTR
1748                                 | NFS_INO_REVAL_FORCED);
1749                 cache_revalidated = false;
1750         }
1751 
1752         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1753                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1754         } else if (server->caps & NFS_CAP_CTIME) {
1755                 nfsi->cache_validity |= save_cache_validity &
1756                                 (NFS_INO_INVALID_ATTR
1757                                 | NFS_INO_REVAL_FORCED);
1758                 cache_revalidated = false;
1759         }
1760 
1761         /* Check if our cached file size is stale */
1762         if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1763                 new_isize = nfs_size_to_loff_t(fattr->size);
1764                 cur_isize = i_size_read(inode);
1765                 if (new_isize != cur_isize) {
1766                         /* Do we perhaps have any outstanding writes, or has
1767                          * the file grown beyond our last write? */
1768                         if (nfsi->nrequests == 0 || new_isize > cur_isize) {
1769                                 i_size_write(inode, new_isize);
1770                                 if (!have_writers)
1771                                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1772                         }
1773                         dprintk("NFS: isize change on server for file %s/%ld "
1774                                         "(%Ld to %Ld)\n",
1775                                         inode->i_sb->s_id,
1776                                         inode->i_ino,
1777                                         (long long)cur_isize,
1778                                         (long long)new_isize);
1779                 }
1780         } else {
1781                 nfsi->cache_validity |= save_cache_validity &
1782                                 (NFS_INO_INVALID_ATTR
1783                                 | NFS_INO_REVAL_PAGECACHE
1784                                 | NFS_INO_REVAL_FORCED);
1785                 cache_revalidated = false;
1786         }
1787 
1788 
1789         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1790                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1791         else if (server->caps & NFS_CAP_ATIME) {
1792                 nfsi->cache_validity |= save_cache_validity &
1793                                 (NFS_INO_INVALID_ATIME
1794                                 | NFS_INO_REVAL_FORCED);
1795                 cache_revalidated = false;
1796         }
1797 
1798         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1799                 if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1800                         umode_t newmode = inode->i_mode & S_IFMT;
1801                         newmode |= fattr->mode & S_IALLUGO;
1802                         inode->i_mode = newmode;
1803                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1804                 }
1805         } else if (server->caps & NFS_CAP_MODE) {
1806                 nfsi->cache_validity |= save_cache_validity &
1807                                 (NFS_INO_INVALID_ATTR
1808                                 | NFS_INO_INVALID_ACCESS
1809                                 | NFS_INO_INVALID_ACL
1810                                 | NFS_INO_REVAL_FORCED);
1811                 cache_revalidated = false;
1812         }
1813 
1814         if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1815                 if (!uid_eq(inode->i_uid, fattr->uid)) {
1816                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1817                         inode->i_uid = fattr->uid;
1818                 }
1819         } else if (server->caps & NFS_CAP_OWNER) {
1820                 nfsi->cache_validity |= save_cache_validity &
1821                                 (NFS_INO_INVALID_ATTR
1822                                 | NFS_INO_INVALID_ACCESS
1823                                 | NFS_INO_INVALID_ACL
1824                                 | NFS_INO_REVAL_FORCED);
1825                 cache_revalidated = false;
1826         }
1827 
1828         if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1829                 if (!gid_eq(inode->i_gid, fattr->gid)) {
1830                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1831                         inode->i_gid = fattr->gid;
1832                 }
1833         } else if (server->caps & NFS_CAP_OWNER_GROUP) {
1834                 nfsi->cache_validity |= save_cache_validity &
1835                                 (NFS_INO_INVALID_ATTR
1836                                 | NFS_INO_INVALID_ACCESS
1837                                 | NFS_INO_INVALID_ACL
1838                                 | NFS_INO_REVAL_FORCED);
1839                 cache_revalidated = false;
1840         }
1841 
1842         if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1843                 if (inode->i_nlink != fattr->nlink) {
1844                         invalid |= NFS_INO_INVALID_ATTR;
1845                         if (S_ISDIR(inode->i_mode))
1846                                 invalid |= NFS_INO_INVALID_DATA;
1847                         set_nlink(inode, fattr->nlink);
1848                 }
1849         } else if (server->caps & NFS_CAP_NLINK) {
1850                 nfsi->cache_validity |= save_cache_validity &
1851                                 (NFS_INO_INVALID_ATTR
1852                                 | NFS_INO_REVAL_FORCED);
1853                 cache_revalidated = false;
1854         }
1855 
1856         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1857                 /*
1858                  * report the blocks in 512byte units
1859                  */
1860                 inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1861         } else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1862                 inode->i_blocks = fattr->du.nfs2.blocks;
1863         else
1864                 cache_revalidated = false;
1865 
1866         /* Update attrtimeo value if we're out of the unstable period */
1867         if (invalid & NFS_INO_INVALID_ATTR) {
1868                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1869                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1870                 nfsi->attrtimeo_timestamp = now;
1871                 /* Set barrier to be more recent than all outstanding updates */
1872                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1873         } else {
1874                 if (cache_revalidated) {
1875                         if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
1876                                 nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1877                                 nfsi->attrtimeo <<= 1;
1878                                 if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
1879                                         nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1880                         }
1881                         nfsi->attrtimeo_timestamp = now;
1882                 }
1883                 /* Set the barrier to be more recent than this fattr */
1884                 if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
1885                         nfsi->attr_gencount = fattr->gencount;
1886         }
1887 
1888         /* Don't declare attrcache up to date if there were no attrs! */
1889         if (cache_revalidated)
1890                 invalid &= ~NFS_INO_INVALID_ATTR;
1891 
1892         /* Don't invalidate the data if we were to blame */
1893         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1894                                 || S_ISLNK(inode->i_mode)))
1895                 invalid &= ~NFS_INO_INVALID_DATA;
1896         if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1897                         (save_cache_validity & NFS_INO_REVAL_FORCED))
1898                 nfs_set_cache_invalid(inode, invalid);
1899 
1900         return 0;
1901  out_err:
1902         /*
1903          * No need to worry about unhashing the dentry, as the
1904          * lookup validation will know that the inode is bad.
1905          * (But we fall through to invalidate the caches.)
1906          */
1907         nfs_invalidate_inode(inode);
1908         return -ESTALE;
1909 }
1910 
1911 struct inode *nfs_alloc_inode(struct super_block *sb)
1912 {
1913         struct nfs_inode *nfsi;
1914         nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1915         if (!nfsi)
1916                 return NULL;
1917         nfsi->flags = 0UL;
1918         nfsi->cache_validity = 0UL;
1919 #if IS_ENABLED(CONFIG_NFS_V4)
1920         nfsi->nfs4_acl = NULL;
1921 #endif /* CONFIG_NFS_V4 */
1922         return &nfsi->vfs_inode;
1923 }
1924 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1925 
1926 static void nfs_i_callback(struct rcu_head *head)
1927 {
1928         struct inode *inode = container_of(head, struct inode, i_rcu);
1929         kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1930 }
1931 
1932 void nfs_destroy_inode(struct inode *inode)
1933 {
1934         call_rcu(&inode->i_rcu, nfs_i_callback);
1935 }
1936 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1937 
1938 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1939 {
1940 #if IS_ENABLED(CONFIG_NFS_V4)
1941         INIT_LIST_HEAD(&nfsi->open_states);
1942         nfsi->delegation = NULL;
1943         init_rwsem(&nfsi->rwsem);
1944         nfsi->layout = NULL;
1945 #endif
1946 }
1947 
1948 static void init_once(void *foo)
1949 {
1950         struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1951 
1952         inode_init_once(&nfsi->vfs_inode);
1953         INIT_LIST_HEAD(&nfsi->open_files);
1954         INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1955         INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1956         INIT_LIST_HEAD(&nfsi->commit_info.list);
1957         nfsi->nrequests = 0;
1958         nfsi->commit_info.ncommit = 0;
1959         atomic_set(&nfsi->commit_info.rpcs_out, 0);
1960         init_rwsem(&nfsi->rmdir_sem);
1961         nfs4_init_once(nfsi);
1962 }
1963 
1964 static int __init nfs_init_inodecache(void)
1965 {
1966         nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1967                                              sizeof(struct nfs_inode),
1968                                              0, (SLAB_RECLAIM_ACCOUNT|
1969                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1970                                              init_once);
1971         if (nfs_inode_cachep == NULL)
1972                 return -ENOMEM;
1973 
1974         return 0;
1975 }
1976 
1977 static void nfs_destroy_inodecache(void)
1978 {
1979         /*
1980          * Make sure all delayed rcu free inodes are flushed before we
1981          * destroy cache.
1982          */
1983         rcu_barrier();
1984         kmem_cache_destroy(nfs_inode_cachep);
1985 }
1986 
1987 struct workqueue_struct *nfsiod_workqueue;
1988 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1989 
1990 /*
1991  * start up the nfsiod workqueue
1992  */
1993 static int nfsiod_start(void)
1994 {
1995         struct workqueue_struct *wq;
1996         dprintk("RPC:       creating workqueue nfsiod\n");
1997         wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1998         if (wq == NULL)
1999                 return -ENOMEM;
2000         nfsiod_workqueue = wq;
2001         return 0;
2002 }
2003 
2004 /*
2005  * Destroy the nfsiod workqueue
2006  */
2007 static void nfsiod_stop(void)
2008 {
2009         struct workqueue_struct *wq;
2010 
2011         wq = nfsiod_workqueue;
2012         if (wq == NULL)
2013                 return;
2014         nfsiod_workqueue = NULL;
2015         destroy_workqueue(wq);
2016 }
2017 
2018 int nfs_net_id;
2019 EXPORT_SYMBOL_GPL(nfs_net_id);
2020 
2021 static int nfs_net_init(struct net *net)
2022 {
2023         nfs_clients_init(net);
2024         return nfs_fs_proc_net_init(net);
2025 }
2026 
2027 static void nfs_net_exit(struct net *net)
2028 {
2029         nfs_fs_proc_net_exit(net);
2030         nfs_cleanup_cb_ident_idr(net);
2031 }
2032 
2033 static struct pernet_operations nfs_net_ops = {
2034         .init = nfs_net_init,
2035         .exit = nfs_net_exit,
2036         .id   = &nfs_net_id,
2037         .size = sizeof(struct nfs_net),
2038 };
2039 
2040 /*
2041  * Initialize NFS
2042  */
2043 static int __init init_nfs_fs(void)
2044 {
2045         int err;
2046 
2047         err = register_pernet_subsys(&nfs_net_ops);
2048         if (err < 0)
2049                 goto out9;
2050 
2051         err = nfs_fscache_register();
2052         if (err < 0)
2053                 goto out8;
2054 
2055         err = nfsiod_start();
2056         if (err)
2057                 goto out7;
2058 
2059         err = nfs_fs_proc_init();
2060         if (err)
2061                 goto out6;
2062 
2063         err = nfs_init_nfspagecache();
2064         if (err)
2065                 goto out5;
2066 
2067         err = nfs_init_inodecache();
2068         if (err)
2069                 goto out4;
2070 
2071         err = nfs_init_readpagecache();
2072         if (err)
2073                 goto out3;
2074 
2075         err = nfs_init_writepagecache();
2076         if (err)
2077                 goto out2;
2078 
2079         err = nfs_init_directcache();
2080         if (err)
2081                 goto out1;
2082 
2083         rpc_proc_register(&init_net, &nfs_rpcstat);
2084 
2085         err = register_nfs_fs();
2086         if (err)
2087                 goto out0;
2088 
2089         return 0;
2090 out0:
2091         rpc_proc_unregister(&init_net, "nfs");
2092         nfs_destroy_directcache();
2093 out1:
2094         nfs_destroy_writepagecache();
2095 out2:
2096         nfs_destroy_readpagecache();
2097 out3:
2098         nfs_destroy_inodecache();
2099 out4:
2100         nfs_destroy_nfspagecache();
2101 out5:
2102         nfs_fs_proc_exit();
2103 out6:
2104         nfsiod_stop();
2105 out7:
2106         nfs_fscache_unregister();
2107 out8:
2108         unregister_pernet_subsys(&nfs_net_ops);
2109 out9:
2110         return err;
2111 }
2112 
2113 static void __exit exit_nfs_fs(void)
2114 {
2115         nfs_destroy_directcache();
2116         nfs_destroy_writepagecache();
2117         nfs_destroy_readpagecache();
2118         nfs_destroy_inodecache();
2119         nfs_destroy_nfspagecache();
2120         nfs_fscache_unregister();
2121         unregister_pernet_subsys(&nfs_net_ops);
2122         rpc_proc_unregister(&init_net, "nfs");
2123         unregister_nfs_fs();
2124         nfs_fs_proc_exit();
2125         nfsiod_stop();
2126 }
2127 
2128 /* Not quite true; I just maintain it */
2129 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2130 MODULE_LICENSE("GPL");
2131 module_param(enable_ino64, bool, 0644);
2132 
2133 module_init(init_nfs_fs)
2134 module_exit(exit_nfs_fs)
2135 

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