3d900916fd41b9c4116d0e72232d814ec86ea836
[linux-3.10.git] / fs / nfs / pnfs.c
1 /*
2  *  pNFS functions to call and manage layout drivers.
3  *
4  *  Copyright (c) 2002 [year of first publication]
5  *  The Regents of the University of Michigan
6  *  All Rights Reserved
7  *
8  *  Dean Hildebrand <dhildebz@umich.edu>
9  *
10  *  Permission is granted to use, copy, create derivative works, and
11  *  redistribute this software and such derivative works for any purpose,
12  *  so long as the name of the University of Michigan is not used in
13  *  any advertising or publicity pertaining to the use or distribution
14  *  of this software without specific, written prior authorization. If
15  *  the above copyright notice or any other identification of the
16  *  University of Michigan is included in any copy of any portion of
17  *  this software, then the disclaimer below must also be included.
18  *
19  *  This software is provided as is, without representation or warranty
20  *  of any kind either express or implied, including without limitation
21  *  the implied warranties of merchantability, fitness for a particular
22  *  purpose, or noninfringement.  The Regents of the University of
23  *  Michigan shall not be liable for any damages, including special,
24  *  indirect, incidental, or consequential damages, with respect to any
25  *  claim arising out of or in connection with the use of the software,
26  *  even if it has been or is hereafter advised of the possibility of
27  *  such damages.
28  */
29
30 #include <linux/nfs_fs.h>
31 #include <linux/nfs_page.h>
32 #include <linux/module.h>
33 #include "internal.h"
34 #include "pnfs.h"
35 #include "iostat.h"
36
37 #define NFSDBG_FACILITY         NFSDBG_PNFS
38 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
39
40 /* Locking:
41  *
42  * pnfs_spinlock:
43  *      protects pnfs_modules_tbl.
44  */
45 static DEFINE_SPINLOCK(pnfs_spinlock);
46
47 /*
48  * pnfs_modules_tbl holds all pnfs modules
49  */
50 static LIST_HEAD(pnfs_modules_tbl);
51
52 /* Return the registered pnfs layout driver module matching given id */
53 static struct pnfs_layoutdriver_type *
54 find_pnfs_driver_locked(u32 id)
55 {
56         struct pnfs_layoutdriver_type *local;
57
58         list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
59                 if (local->id == id)
60                         goto out;
61         local = NULL;
62 out:
63         dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
64         return local;
65 }
66
67 static struct pnfs_layoutdriver_type *
68 find_pnfs_driver(u32 id)
69 {
70         struct pnfs_layoutdriver_type *local;
71
72         spin_lock(&pnfs_spinlock);
73         local = find_pnfs_driver_locked(id);
74         if (local != NULL && !try_module_get(local->owner)) {
75                 dprintk("%s: Could not grab reference on module\n", __func__);
76                 local = NULL;
77         }
78         spin_unlock(&pnfs_spinlock);
79         return local;
80 }
81
82 void
83 unset_pnfs_layoutdriver(struct nfs_server *nfss)
84 {
85         if (nfss->pnfs_curr_ld) {
86                 if (nfss->pnfs_curr_ld->clear_layoutdriver)
87                         nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
88                 /* Decrement the MDS count. Purge the deviceid cache if zero */
89                 if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
90                         nfs4_deviceid_purge_client(nfss->nfs_client);
91                 module_put(nfss->pnfs_curr_ld->owner);
92         }
93         nfss->pnfs_curr_ld = NULL;
94 }
95
96 /*
97  * Try to set the server's pnfs module to the pnfs layout type specified by id.
98  * Currently only one pNFS layout driver per filesystem is supported.
99  *
100  * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
101  */
102 void
103 set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
104                       u32 id)
105 {
106         struct pnfs_layoutdriver_type *ld_type = NULL;
107
108         if (id == 0)
109                 goto out_no_driver;
110         if (!(server->nfs_client->cl_exchange_flags &
111                  (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
112                 printk(KERN_ERR "NFS: %s: id %u cl_exchange_flags 0x%x\n",
113                         __func__, id, server->nfs_client->cl_exchange_flags);
114                 goto out_no_driver;
115         }
116         ld_type = find_pnfs_driver(id);
117         if (!ld_type) {
118                 request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
119                 ld_type = find_pnfs_driver(id);
120                 if (!ld_type) {
121                         dprintk("%s: No pNFS module found for %u.\n",
122                                 __func__, id);
123                         goto out_no_driver;
124                 }
125         }
126         server->pnfs_curr_ld = ld_type;
127         if (ld_type->set_layoutdriver
128             && ld_type->set_layoutdriver(server, mntfh)) {
129                 printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
130                         "driver %u.\n", __func__, id);
131                 module_put(ld_type->owner);
132                 goto out_no_driver;
133         }
134         /* Bump the MDS count */
135         atomic_inc(&server->nfs_client->cl_mds_count);
136
137         dprintk("%s: pNFS module for %u set\n", __func__, id);
138         return;
139
140 out_no_driver:
141         dprintk("%s: Using NFSv4 I/O\n", __func__);
142         server->pnfs_curr_ld = NULL;
143 }
144
145 int
146 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
147 {
148         int status = -EINVAL;
149         struct pnfs_layoutdriver_type *tmp;
150
151         if (ld_type->id == 0) {
152                 printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
153                 return status;
154         }
155         if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
156                 printk(KERN_ERR "NFS: %s Layout driver must provide "
157                        "alloc_lseg and free_lseg.\n", __func__);
158                 return status;
159         }
160
161         spin_lock(&pnfs_spinlock);
162         tmp = find_pnfs_driver_locked(ld_type->id);
163         if (!tmp) {
164                 list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
165                 status = 0;
166                 dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
167                         ld_type->name);
168         } else {
169                 printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
170                         __func__, ld_type->id);
171         }
172         spin_unlock(&pnfs_spinlock);
173
174         return status;
175 }
176 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
177
178 void
179 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
180 {
181         dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
182         spin_lock(&pnfs_spinlock);
183         list_del(&ld_type->pnfs_tblid);
184         spin_unlock(&pnfs_spinlock);
185 }
186 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
187
188 /*
189  * pNFS client layout cache
190  */
191
192 /* Need to hold i_lock if caller does not already hold reference */
193 void
194 pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
195 {
196         atomic_inc(&lo->plh_refcount);
197 }
198
199 static struct pnfs_layout_hdr *
200 pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
201 {
202         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
203         return ld->alloc_layout_hdr(ino, gfp_flags);
204 }
205
206 static void
207 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
208 {
209         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
210         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
211
212         if (!list_empty(&lo->plh_layouts)) {
213                 struct nfs_client *clp = server->nfs_client;
214
215                 spin_lock(&clp->cl_lock);
216                 list_del_init(&lo->plh_layouts);
217                 spin_unlock(&clp->cl_lock);
218         }
219         put_rpccred(lo->plh_lc_cred);
220         return ld->free_layout_hdr(lo);
221 }
222
223 static void
224 pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
225 {
226         struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
227         dprintk("%s: freeing layout cache %p\n", __func__, lo);
228         nfsi->layout = NULL;
229         /* Reset MDS Threshold I/O counters */
230         nfsi->write_io = 0;
231         nfsi->read_io = 0;
232 }
233
234 void
235 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
236 {
237         struct inode *inode = lo->plh_inode;
238
239         if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
240                 pnfs_detach_layout_hdr(lo);
241                 spin_unlock(&inode->i_lock);
242                 pnfs_free_layout_hdr(lo);
243         }
244 }
245
246 static int
247 pnfs_iomode_to_fail_bit(u32 iomode)
248 {
249         return iomode == IOMODE_RW ?
250                 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
251 }
252
253 static void
254 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
255 {
256         lo->plh_retry_timestamp = jiffies;
257         if (!test_and_set_bit(fail_bit, &lo->plh_flags))
258                 atomic_inc(&lo->plh_refcount);
259 }
260
261 static void
262 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
263 {
264         if (test_and_clear_bit(fail_bit, &lo->plh_flags))
265                 atomic_dec(&lo->plh_refcount);
266 }
267
268 static void
269 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
270 {
271         struct inode *inode = lo->plh_inode;
272         struct pnfs_layout_range range = {
273                 .iomode = iomode,
274                 .offset = 0,
275                 .length = NFS4_MAX_UINT64,
276         };
277         LIST_HEAD(head);
278
279         spin_lock(&inode->i_lock);
280         pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
281         pnfs_mark_matching_lsegs_invalid(lo, &head, &range);
282         spin_unlock(&inode->i_lock);
283         pnfs_free_lseg_list(&head);
284         dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
285                         iomode == IOMODE_RW ?  "RW" : "READ");
286 }
287
288 static bool
289 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
290 {
291         unsigned long start, end;
292         int fail_bit = pnfs_iomode_to_fail_bit(iomode);
293
294         if (test_bit(fail_bit, &lo->plh_flags) == 0)
295                 return false;
296         end = jiffies;
297         start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
298         if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
299                 /* It is time to retry the failed layoutgets */
300                 pnfs_layout_clear_fail_bit(lo, fail_bit);
301                 return false;
302         }
303         return true;
304 }
305
306 static void
307 init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
308 {
309         INIT_LIST_HEAD(&lseg->pls_list);
310         INIT_LIST_HEAD(&lseg->pls_lc_list);
311         atomic_set(&lseg->pls_refcount, 1);
312         smp_mb();
313         set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
314         lseg->pls_layout = lo;
315 }
316
317 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
318 {
319         struct inode *ino = lseg->pls_layout->plh_inode;
320
321         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
322 }
323
324 static void
325 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
326                 struct pnfs_layout_segment *lseg)
327 {
328         struct inode *inode = lo->plh_inode;
329
330         WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
331         list_del_init(&lseg->pls_list);
332         /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
333         atomic_dec(&lo->plh_refcount);
334         if (list_empty(&lo->plh_segs))
335                 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
336         rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
337 }
338
339 void
340 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
341 {
342         struct pnfs_layout_hdr *lo;
343         struct inode *inode;
344
345         if (!lseg)
346                 return;
347
348         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
349                 atomic_read(&lseg->pls_refcount),
350                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
351         lo = lseg->pls_layout;
352         inode = lo->plh_inode;
353         if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
354                 pnfs_get_layout_hdr(lo);
355                 pnfs_layout_remove_lseg(lo, lseg);
356                 spin_unlock(&inode->i_lock);
357                 pnfs_free_lseg(lseg);
358                 pnfs_put_layout_hdr(lo);
359         }
360 }
361 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
362
363 static inline u64
364 end_offset(u64 start, u64 len)
365 {
366         u64 end;
367
368         end = start + len;
369         return end >= start ? end : NFS4_MAX_UINT64;
370 }
371
372 /*
373  * is l2 fully contained in l1?
374  *   start1                             end1
375  *   [----------------------------------)
376  *           start2           end2
377  *           [----------------)
378  */
379 static inline int
380 lo_seg_contained(struct pnfs_layout_range *l1,
381                  struct pnfs_layout_range *l2)
382 {
383         u64 start1 = l1->offset;
384         u64 end1 = end_offset(start1, l1->length);
385         u64 start2 = l2->offset;
386         u64 end2 = end_offset(start2, l2->length);
387
388         return (start1 <= start2) && (end1 >= end2);
389 }
390
391 /*
392  * is l1 and l2 intersecting?
393  *   start1                             end1
394  *   [----------------------------------)
395  *                              start2           end2
396  *                              [----------------)
397  */
398 static inline int
399 lo_seg_intersecting(struct pnfs_layout_range *l1,
400                     struct pnfs_layout_range *l2)
401 {
402         u64 start1 = l1->offset;
403         u64 end1 = end_offset(start1, l1->length);
404         u64 start2 = l2->offset;
405         u64 end2 = end_offset(start2, l2->length);
406
407         return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
408                (end2 == NFS4_MAX_UINT64 || end2 > start1);
409 }
410
411 static bool
412 should_free_lseg(struct pnfs_layout_range *lseg_range,
413                  struct pnfs_layout_range *recall_range)
414 {
415         return (recall_range->iomode == IOMODE_ANY ||
416                 lseg_range->iomode == recall_range->iomode) &&
417                lo_seg_intersecting(lseg_range, recall_range);
418 }
419
420 /* Returns 1 if lseg is removed from list, 0 otherwise */
421 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
422                              struct list_head *tmp_list)
423 {
424         int rv = 0;
425
426         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
427                 /* Remove the reference keeping the lseg in the
428                  * list.  It will now be removed when all
429                  * outstanding io is finished.
430                  */
431                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
432                         atomic_read(&lseg->pls_refcount));
433                 if (atomic_dec_and_test(&lseg->pls_refcount)) {
434                         pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
435                         list_add(&lseg->pls_list, tmp_list);
436                         rv = 1;
437                 }
438         }
439         return rv;
440 }
441
442 /* Returns count of number of matching invalid lsegs remaining in list
443  * after call.
444  */
445 int
446 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
447                             struct list_head *tmp_list,
448                             struct pnfs_layout_range *recall_range)
449 {
450         struct pnfs_layout_segment *lseg, *next;
451         int invalid = 0, removed = 0;
452
453         dprintk("%s:Begin lo %p\n", __func__, lo);
454
455         if (list_empty(&lo->plh_segs))
456                 return 0;
457         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
458                 if (!recall_range ||
459                     should_free_lseg(&lseg->pls_range, recall_range)) {
460                         dprintk("%s: freeing lseg %p iomode %d "
461                                 "offset %llu length %llu\n", __func__,
462                                 lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
463                                 lseg->pls_range.length);
464                         invalid++;
465                         removed += mark_lseg_invalid(lseg, tmp_list);
466                 }
467         dprintk("%s:Return %i\n", __func__, invalid - removed);
468         return invalid - removed;
469 }
470
471 /* note free_me must contain lsegs from a single layout_hdr */
472 void
473 pnfs_free_lseg_list(struct list_head *free_me)
474 {
475         struct pnfs_layout_segment *lseg, *tmp;
476
477         if (list_empty(free_me))
478                 return;
479
480         list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
481                 list_del(&lseg->pls_list);
482                 pnfs_free_lseg(lseg);
483         }
484 }
485
486 void
487 pnfs_destroy_layout(struct nfs_inode *nfsi)
488 {
489         struct pnfs_layout_hdr *lo;
490         LIST_HEAD(tmp_list);
491
492         spin_lock(&nfsi->vfs_inode.i_lock);
493         lo = nfsi->layout;
494         if (lo) {
495                 lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
496                 pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
497                 pnfs_get_layout_hdr(lo);
498                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
499                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
500                 spin_unlock(&nfsi->vfs_inode.i_lock);
501                 pnfs_free_lseg_list(&tmp_list);
502                 pnfs_put_layout_hdr(lo);
503         } else
504                 spin_unlock(&nfsi->vfs_inode.i_lock);
505 }
506 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
507
508 static bool
509 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
510                 struct list_head *layout_list)
511 {
512         struct pnfs_layout_hdr *lo;
513         bool ret = false;
514
515         spin_lock(&inode->i_lock);
516         lo = NFS_I(inode)->layout;
517         if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
518                 pnfs_get_layout_hdr(lo);
519                 list_add(&lo->plh_bulk_destroy, layout_list);
520                 ret = true;
521         }
522         spin_unlock(&inode->i_lock);
523         return ret;
524 }
525
526 /* Caller must hold rcu_read_lock and clp->cl_lock */
527 static int
528 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
529                 struct nfs_server *server,
530                 struct list_head *layout_list)
531 {
532         struct pnfs_layout_hdr *lo, *next;
533         struct inode *inode;
534
535         list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
536                 inode = igrab(lo->plh_inode);
537                 if (inode == NULL)
538                         continue;
539                 list_del_init(&lo->plh_layouts);
540                 if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
541                         continue;
542                 rcu_read_unlock();
543                 spin_unlock(&clp->cl_lock);
544                 iput(inode);
545                 spin_lock(&clp->cl_lock);
546                 rcu_read_lock();
547                 return -EAGAIN;
548         }
549         return 0;
550 }
551
552 static int
553 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
554                 bool is_bulk_recall)
555 {
556         struct pnfs_layout_hdr *lo;
557         struct inode *inode;
558         struct pnfs_layout_range range = {
559                 .iomode = IOMODE_ANY,
560                 .offset = 0,
561                 .length = NFS4_MAX_UINT64,
562         };
563         LIST_HEAD(lseg_list);
564         int ret = 0;
565
566         while (!list_empty(layout_list)) {
567                 lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
568                                 plh_bulk_destroy);
569                 dprintk("%s freeing layout for inode %lu\n", __func__,
570                         lo->plh_inode->i_ino);
571                 inode = lo->plh_inode;
572                 spin_lock(&inode->i_lock);
573                 list_del_init(&lo->plh_bulk_destroy);
574                 lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
575                 if (is_bulk_recall)
576                         set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
577                 if (pnfs_mark_matching_lsegs_invalid(lo, &lseg_list, &range))
578                         ret = -EAGAIN;
579                 spin_unlock(&inode->i_lock);
580                 pnfs_free_lseg_list(&lseg_list);
581                 pnfs_put_layout_hdr(lo);
582                 iput(inode);
583         }
584         return ret;
585 }
586
587 int
588 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
589                 struct nfs_fsid *fsid,
590                 bool is_recall)
591 {
592         struct nfs_server *server;
593         LIST_HEAD(layout_list);
594
595         spin_lock(&clp->cl_lock);
596         rcu_read_lock();
597 restart:
598         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
599                 if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
600                         continue;
601                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
602                                 server,
603                                 &layout_list) != 0)
604                         goto restart;
605         }
606         rcu_read_unlock();
607         spin_unlock(&clp->cl_lock);
608
609         if (list_empty(&layout_list))
610                 return 0;
611         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
612 }
613
614 int
615 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
616                 bool is_recall)
617 {
618         struct nfs_server *server;
619         LIST_HEAD(layout_list);
620
621         spin_lock(&clp->cl_lock);
622         rcu_read_lock();
623 restart:
624         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
625                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
626                                         server,
627                                         &layout_list) != 0)
628                         goto restart;
629         }
630         rcu_read_unlock();
631         spin_unlock(&clp->cl_lock);
632
633         if (list_empty(&layout_list))
634                 return 0;
635         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
636 }
637
638 /*
639  * Called by the state manger to remove all layouts established under an
640  * expired lease.
641  */
642 void
643 pnfs_destroy_all_layouts(struct nfs_client *clp)
644 {
645         nfs4_deviceid_mark_client_invalid(clp);
646         nfs4_deviceid_purge_client(clp);
647
648         pnfs_destroy_layouts_byclid(clp, false);
649 }
650
651 /*
652  * Compare 2 layout stateid sequence ids, to see which is newer,
653  * taking into account wraparound issues.
654  */
655 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
656 {
657         return (s32)s1 - (s32)s2 > 0;
658 }
659
660 /* update lo->plh_stateid with new if is more recent */
661 void
662 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
663                         bool update_barrier)
664 {
665         u32 oldseq, newseq, new_barrier;
666         int empty = list_empty(&lo->plh_segs);
667
668         oldseq = be32_to_cpu(lo->plh_stateid.seqid);
669         newseq = be32_to_cpu(new->seqid);
670         if (empty || pnfs_seqid_is_newer(newseq, oldseq)) {
671                 nfs4_stateid_copy(&lo->plh_stateid, new);
672                 if (update_barrier) {
673                         new_barrier = be32_to_cpu(new->seqid);
674                 } else {
675                         /* Because of wraparound, we want to keep the barrier
676                          * "close" to the current seqids.
677                          */
678                         new_barrier = newseq - atomic_read(&lo->plh_outstanding);
679                 }
680                 if (empty || pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
681                         lo->plh_barrier = new_barrier;
682         }
683 }
684
685 static bool
686 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
687                 const nfs4_stateid *stateid)
688 {
689         u32 seqid = be32_to_cpu(stateid->seqid);
690
691         return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
692 }
693
694 /* lget is set to 1 if called from inside send_layoutget call chain */
695 static bool
696 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo, int lget)
697 {
698         return lo->plh_block_lgets ||
699                 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
700                 (list_empty(&lo->plh_segs) &&
701                  (atomic_read(&lo->plh_outstanding) > lget));
702 }
703
704 int
705 pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
706                               struct nfs4_state *open_state)
707 {
708         int status = 0;
709
710         dprintk("--> %s\n", __func__);
711         spin_lock(&lo->plh_inode->i_lock);
712         if (pnfs_layoutgets_blocked(lo, 1)) {
713                 status = -EAGAIN;
714         } else if (list_empty(&lo->plh_segs)) {
715                 int seq;
716
717                 do {
718                         seq = read_seqbegin(&open_state->seqlock);
719                         nfs4_stateid_copy(dst, &open_state->stateid);
720                 } while (read_seqretry(&open_state->seqlock, seq));
721         } else
722                 nfs4_stateid_copy(dst, &lo->plh_stateid);
723         spin_unlock(&lo->plh_inode->i_lock);
724         dprintk("<-- %s\n", __func__);
725         return status;
726 }
727
728 /*
729 * Get layout from server.
730 *    for now, assume that whole file layouts are requested.
731 *    arg->offset: 0
732 *    arg->length: all ones
733 */
734 static struct pnfs_layout_segment *
735 send_layoutget(struct pnfs_layout_hdr *lo,
736            struct nfs_open_context *ctx,
737            struct pnfs_layout_range *range,
738            gfp_t gfp_flags)
739 {
740         struct inode *ino = lo->plh_inode;
741         struct nfs_server *server = NFS_SERVER(ino);
742         struct nfs4_layoutget *lgp;
743         struct pnfs_layout_segment *lseg;
744
745         dprintk("--> %s\n", __func__);
746
747         lgp = kzalloc(sizeof(*lgp), gfp_flags);
748         if (lgp == NULL)
749                 return NULL;
750
751         lgp->args.minlength = PAGE_CACHE_SIZE;
752         if (lgp->args.minlength > range->length)
753                 lgp->args.minlength = range->length;
754         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
755         lgp->args.range = *range;
756         lgp->args.type = server->pnfs_curr_ld->id;
757         lgp->args.inode = ino;
758         lgp->args.ctx = get_nfs_open_context(ctx);
759         lgp->gfp_flags = gfp_flags;
760
761         /* Synchronously retrieve layout information from server and
762          * store in lseg.
763          */
764         lseg = nfs4_proc_layoutget(lgp, gfp_flags);
765         if (IS_ERR(lseg)) {
766                 switch (PTR_ERR(lseg)) {
767                 case -ENOMEM:
768                 case -ERESTARTSYS:
769                         break;
770                 default:
771                         /* remember that LAYOUTGET failed and suspend trying */
772                         pnfs_layout_io_set_failed(lo, range->iomode);
773                 }
774                 return NULL;
775         }
776
777         return lseg;
778 }
779
780 /*
781  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
782  * when the layout segment list is empty.
783  *
784  * Note that a pnfs_layout_hdr can exist with an empty layout segment
785  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
786  * deviceid is marked invalid.
787  */
788 int
789 _pnfs_return_layout(struct inode *ino)
790 {
791         struct pnfs_layout_hdr *lo = NULL;
792         struct nfs_inode *nfsi = NFS_I(ino);
793         LIST_HEAD(tmp_list);
794         struct nfs4_layoutreturn *lrp;
795         nfs4_stateid stateid;
796         int status = 0, empty;
797
798         dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
799
800         spin_lock(&ino->i_lock);
801         lo = nfsi->layout;
802         if (!lo) {
803                 spin_unlock(&ino->i_lock);
804                 dprintk("NFS: %s no layout to return\n", __func__);
805                 goto out;
806         }
807         stateid = nfsi->layout->plh_stateid;
808         /* Reference matched in nfs4_layoutreturn_release */
809         pnfs_get_layout_hdr(lo);
810         empty = list_empty(&lo->plh_segs);
811         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
812         /* Don't send a LAYOUTRETURN if list was initially empty */
813         if (empty) {
814                 spin_unlock(&ino->i_lock);
815                 pnfs_put_layout_hdr(lo);
816                 dprintk("NFS: %s no layout segments to return\n", __func__);
817                 goto out;
818         }
819         lo->plh_block_lgets++;
820         spin_unlock(&ino->i_lock);
821         pnfs_free_lseg_list(&tmp_list);
822
823         WARN_ON(test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags));
824
825         lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
826         if (unlikely(lrp == NULL)) {
827                 status = -ENOMEM;
828                 spin_lock(&ino->i_lock);
829                 lo->plh_block_lgets--;
830                 spin_unlock(&ino->i_lock);
831                 pnfs_put_layout_hdr(lo);
832                 goto out;
833         }
834
835         lrp->args.stateid = stateid;
836         lrp->args.layout_type = NFS_SERVER(ino)->pnfs_curr_ld->id;
837         lrp->args.inode = ino;
838         lrp->args.layout = lo;
839         lrp->clp = NFS_SERVER(ino)->nfs_client;
840
841         status = nfs4_proc_layoutreturn(lrp);
842 out:
843         dprintk("<-- %s status: %d\n", __func__, status);
844         return status;
845 }
846 EXPORT_SYMBOL_GPL(_pnfs_return_layout);
847
848 bool pnfs_roc(struct inode *ino)
849 {
850         struct pnfs_layout_hdr *lo;
851         struct pnfs_layout_segment *lseg, *tmp;
852         LIST_HEAD(tmp_list);
853         bool found = false;
854
855         spin_lock(&ino->i_lock);
856         lo = NFS_I(ino)->layout;
857         if (!lo || !test_and_clear_bit(NFS_LAYOUT_ROC, &lo->plh_flags) ||
858             test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
859                 goto out_nolayout;
860         list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
861                 if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
862                         mark_lseg_invalid(lseg, &tmp_list);
863                         found = true;
864                 }
865         if (!found)
866                 goto out_nolayout;
867         lo->plh_block_lgets++;
868         pnfs_get_layout_hdr(lo); /* matched in pnfs_roc_release */
869         spin_unlock(&ino->i_lock);
870         pnfs_free_lseg_list(&tmp_list);
871         return true;
872
873 out_nolayout:
874         spin_unlock(&ino->i_lock);
875         return false;
876 }
877
878 void pnfs_roc_release(struct inode *ino)
879 {
880         struct pnfs_layout_hdr *lo;
881
882         spin_lock(&ino->i_lock);
883         lo = NFS_I(ino)->layout;
884         lo->plh_block_lgets--;
885         if (atomic_dec_and_test(&lo->plh_refcount)) {
886                 pnfs_detach_layout_hdr(lo);
887                 spin_unlock(&ino->i_lock);
888                 pnfs_free_layout_hdr(lo);
889         } else
890                 spin_unlock(&ino->i_lock);
891 }
892
893 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
894 {
895         struct pnfs_layout_hdr *lo;
896
897         spin_lock(&ino->i_lock);
898         lo = NFS_I(ino)->layout;
899         if (pnfs_seqid_is_newer(barrier, lo->plh_barrier))
900                 lo->plh_barrier = barrier;
901         spin_unlock(&ino->i_lock);
902 }
903
904 bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
905 {
906         struct nfs_inode *nfsi = NFS_I(ino);
907         struct pnfs_layout_hdr *lo;
908         struct pnfs_layout_segment *lseg;
909         u32 current_seqid;
910         bool found = false;
911
912         spin_lock(&ino->i_lock);
913         list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list)
914                 if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
915                         rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
916                         found = true;
917                         goto out;
918                 }
919         lo = nfsi->layout;
920         current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
921
922         /* Since close does not return a layout stateid for use as
923          * a barrier, we choose the worst-case barrier.
924          */
925         *barrier = current_seqid + atomic_read(&lo->plh_outstanding);
926 out:
927         spin_unlock(&ino->i_lock);
928         return found;
929 }
930
931 /*
932  * Compare two layout segments for sorting into layout cache.
933  * We want to preferentially return RW over RO layouts, so ensure those
934  * are seen first.
935  */
936 static s64
937 cmp_layout(struct pnfs_layout_range *l1,
938            struct pnfs_layout_range *l2)
939 {
940         s64 d;
941
942         /* high offset > low offset */
943         d = l1->offset - l2->offset;
944         if (d)
945                 return d;
946
947         /* short length > long length */
948         d = l2->length - l1->length;
949         if (d)
950                 return d;
951
952         /* read > read/write */
953         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
954 }
955
956 static void
957 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
958                    struct pnfs_layout_segment *lseg)
959 {
960         struct pnfs_layout_segment *lp;
961
962         dprintk("%s:Begin\n", __func__);
963
964         list_for_each_entry(lp, &lo->plh_segs, pls_list) {
965                 if (cmp_layout(&lseg->pls_range, &lp->pls_range) > 0)
966                         continue;
967                 list_add_tail(&lseg->pls_list, &lp->pls_list);
968                 dprintk("%s: inserted lseg %p "
969                         "iomode %d offset %llu length %llu before "
970                         "lp %p iomode %d offset %llu length %llu\n",
971                         __func__, lseg, lseg->pls_range.iomode,
972                         lseg->pls_range.offset, lseg->pls_range.length,
973                         lp, lp->pls_range.iomode, lp->pls_range.offset,
974                         lp->pls_range.length);
975                 goto out;
976         }
977         list_add_tail(&lseg->pls_list, &lo->plh_segs);
978         dprintk("%s: inserted lseg %p "
979                 "iomode %d offset %llu length %llu at tail\n",
980                 __func__, lseg, lseg->pls_range.iomode,
981                 lseg->pls_range.offset, lseg->pls_range.length);
982 out:
983         pnfs_get_layout_hdr(lo);
984
985         dprintk("%s:Return\n", __func__);
986 }
987
988 static struct pnfs_layout_hdr *
989 alloc_init_layout_hdr(struct inode *ino,
990                       struct nfs_open_context *ctx,
991                       gfp_t gfp_flags)
992 {
993         struct pnfs_layout_hdr *lo;
994
995         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
996         if (!lo)
997                 return NULL;
998         atomic_set(&lo->plh_refcount, 1);
999         INIT_LIST_HEAD(&lo->plh_layouts);
1000         INIT_LIST_HEAD(&lo->plh_segs);
1001         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1002         lo->plh_inode = ino;
1003         lo->plh_lc_cred = get_rpccred(ctx->state->owner->so_cred);
1004         return lo;
1005 }
1006
1007 static struct pnfs_layout_hdr *
1008 pnfs_find_alloc_layout(struct inode *ino,
1009                        struct nfs_open_context *ctx,
1010                        gfp_t gfp_flags)
1011 {
1012         struct nfs_inode *nfsi = NFS_I(ino);
1013         struct pnfs_layout_hdr *new = NULL;
1014
1015         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1016
1017         if (nfsi->layout != NULL)
1018                 goto out_existing;
1019         spin_unlock(&ino->i_lock);
1020         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1021         spin_lock(&ino->i_lock);
1022
1023         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1024                 nfsi->layout = new;
1025                 return new;
1026         } else if (new != NULL)
1027                 pnfs_free_layout_hdr(new);
1028 out_existing:
1029         pnfs_get_layout_hdr(nfsi->layout);
1030         return nfsi->layout;
1031 }
1032
1033 /*
1034  * iomode matching rules:
1035  * iomode       lseg    match
1036  * -----        -----   -----
1037  * ANY          READ    true
1038  * ANY          RW      true
1039  * RW           READ    false
1040  * RW           RW      true
1041  * READ         READ    true
1042  * READ         RW      true
1043  */
1044 static int
1045 is_matching_lseg(struct pnfs_layout_range *ls_range,
1046                  struct pnfs_layout_range *range)
1047 {
1048         struct pnfs_layout_range range1;
1049
1050         if ((range->iomode == IOMODE_RW &&
1051              ls_range->iomode != IOMODE_RW) ||
1052             !lo_seg_intersecting(ls_range, range))
1053                 return 0;
1054
1055         /* range1 covers only the first byte in the range */
1056         range1 = *range;
1057         range1.length = 1;
1058         return lo_seg_contained(ls_range, &range1);
1059 }
1060
1061 /*
1062  * lookup range in layout
1063  */
1064 static struct pnfs_layout_segment *
1065 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1066                 struct pnfs_layout_range *range)
1067 {
1068         struct pnfs_layout_segment *lseg, *ret = NULL;
1069
1070         dprintk("%s:Begin\n", __func__);
1071
1072         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1073                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1074                     is_matching_lseg(&lseg->pls_range, range)) {
1075                         ret = pnfs_get_lseg(lseg);
1076                         break;
1077                 }
1078                 if (lseg->pls_range.offset > range->offset)
1079                         break;
1080         }
1081
1082         dprintk("%s:Return lseg %p ref %d\n",
1083                 __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1084         return ret;
1085 }
1086
1087 /*
1088  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1089  * to the MDS or over pNFS
1090  *
1091  * The nfs_inode read_io and write_io fields are cumulative counters reset
1092  * when there are no layout segments. Note that in pnfs_update_layout iomode
1093  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1094  * WRITE request.
1095  *
1096  * A return of true means use MDS I/O.
1097  *
1098  * From rfc 5661:
1099  * If a file's size is smaller than the file size threshold, data accesses
1100  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1101  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1102  * server.  If both file size and I/O size are provided, the client SHOULD
1103  * reach or exceed  both thresholds before sending its read or write
1104  * requests to the data server.
1105  */
1106 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1107                                      struct inode *ino, int iomode)
1108 {
1109         struct nfs4_threshold *t = ctx->mdsthreshold;
1110         struct nfs_inode *nfsi = NFS_I(ino);
1111         loff_t fsize = i_size_read(ino);
1112         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1113
1114         if (t == NULL)
1115                 return ret;
1116
1117         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1118                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1119
1120         switch (iomode) {
1121         case IOMODE_READ:
1122                 if (t->bm & THRESHOLD_RD) {
1123                         dprintk("%s fsize %llu\n", __func__, fsize);
1124                         size_set = true;
1125                         if (fsize < t->rd_sz)
1126                                 size = true;
1127                 }
1128                 if (t->bm & THRESHOLD_RD_IO) {
1129                         dprintk("%s nfsi->read_io %llu\n", __func__,
1130                                 nfsi->read_io);
1131                         io_set = true;
1132                         if (nfsi->read_io < t->rd_io_sz)
1133                                 io = true;
1134                 }
1135                 break;
1136         case IOMODE_RW:
1137                 if (t->bm & THRESHOLD_WR) {
1138                         dprintk("%s fsize %llu\n", __func__, fsize);
1139                         size_set = true;
1140                         if (fsize < t->wr_sz)
1141                                 size = true;
1142                 }
1143                 if (t->bm & THRESHOLD_WR_IO) {
1144                         dprintk("%s nfsi->write_io %llu\n", __func__,
1145                                 nfsi->write_io);
1146                         io_set = true;
1147                         if (nfsi->write_io < t->wr_io_sz)
1148                                 io = true;
1149                 }
1150                 break;
1151         }
1152         if (size_set && io_set) {
1153                 if (size && io)
1154                         ret = true;
1155         } else if (size || io)
1156                 ret = true;
1157
1158         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1159         return ret;
1160 }
1161
1162 /*
1163  * Layout segment is retreived from the server if not cached.
1164  * The appropriate layout segment is referenced and returned to the caller.
1165  */
1166 struct pnfs_layout_segment *
1167 pnfs_update_layout(struct inode *ino,
1168                    struct nfs_open_context *ctx,
1169                    loff_t pos,
1170                    u64 count,
1171                    enum pnfs_iomode iomode,
1172                    gfp_t gfp_flags)
1173 {
1174         struct pnfs_layout_range arg = {
1175                 .iomode = iomode,
1176                 .offset = pos,
1177                 .length = count,
1178         };
1179         unsigned pg_offset;
1180         struct nfs_server *server = NFS_SERVER(ino);
1181         struct nfs_client *clp = server->nfs_client;
1182         struct pnfs_layout_hdr *lo;
1183         struct pnfs_layout_segment *lseg = NULL;
1184         bool first;
1185
1186         if (!pnfs_enabled_sb(NFS_SERVER(ino)))
1187                 goto out;
1188
1189         if (pnfs_within_mdsthreshold(ctx, ino, iomode))
1190                 goto out;
1191
1192         spin_lock(&ino->i_lock);
1193         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1194         if (lo == NULL) {
1195                 spin_unlock(&ino->i_lock);
1196                 goto out;
1197         }
1198
1199         /* Do we even need to bother with this? */
1200         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1201                 dprintk("%s matches recall, use MDS\n", __func__);
1202                 goto out_unlock;
1203         }
1204
1205         /* if LAYOUTGET already failed once we don't try again */
1206         if (pnfs_layout_io_test_failed(lo, iomode))
1207                 goto out_unlock;
1208
1209         /* Check to see if the layout for the given range already exists */
1210         lseg = pnfs_find_lseg(lo, &arg);
1211         if (lseg)
1212                 goto out_unlock;
1213
1214         if (pnfs_layoutgets_blocked(lo, 0))
1215                 goto out_unlock;
1216         atomic_inc(&lo->plh_outstanding);
1217
1218         first = list_empty(&lo->plh_layouts) ? true : false;
1219         spin_unlock(&ino->i_lock);
1220
1221         if (first) {
1222                 /* The lo must be on the clp list if there is any
1223                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1224                  */
1225                 spin_lock(&clp->cl_lock);
1226                 list_add_tail(&lo->plh_layouts, &server->layouts);
1227                 spin_unlock(&clp->cl_lock);
1228         }
1229
1230         pg_offset = arg.offset & ~PAGE_CACHE_MASK;
1231         if (pg_offset) {
1232                 arg.offset -= pg_offset;
1233                 arg.length += pg_offset;
1234         }
1235         if (arg.length != NFS4_MAX_UINT64)
1236                 arg.length = PAGE_CACHE_ALIGN(arg.length);
1237
1238         lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
1239         atomic_dec(&lo->plh_outstanding);
1240 out_put_layout_hdr:
1241         pnfs_put_layout_hdr(lo);
1242 out:
1243         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1244                         "(%s, offset: %llu, length: %llu)\n",
1245                         __func__, ino->i_sb->s_id,
1246                         (unsigned long long)NFS_FILEID(ino),
1247                         lseg == NULL ? "not found" : "found",
1248                         iomode==IOMODE_RW ?  "read/write" : "read-only",
1249                         (unsigned long long)pos,
1250                         (unsigned long long)count);
1251         return lseg;
1252 out_unlock:
1253         spin_unlock(&ino->i_lock);
1254         goto out_put_layout_hdr;
1255 }
1256 EXPORT_SYMBOL_GPL(pnfs_update_layout);
1257
1258 struct pnfs_layout_segment *
1259 pnfs_layout_process(struct nfs4_layoutget *lgp)
1260 {
1261         struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1262         struct nfs4_layoutget_res *res = &lgp->res;
1263         struct pnfs_layout_segment *lseg;
1264         struct inode *ino = lo->plh_inode;
1265         int status = 0;
1266
1267         /* Inject layout blob into I/O device driver */
1268         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1269         if (!lseg || IS_ERR(lseg)) {
1270                 if (!lseg)
1271                         status = -ENOMEM;
1272                 else
1273                         status = PTR_ERR(lseg);
1274                 dprintk("%s: Could not allocate layout: error %d\n",
1275                        __func__, status);
1276                 goto out;
1277         }
1278
1279         spin_lock(&ino->i_lock);
1280         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1281                 dprintk("%s forget reply due to recall\n", __func__);
1282                 goto out_forget_reply;
1283         }
1284
1285         if (pnfs_layoutgets_blocked(lo, 1) ||
1286             pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1287                 dprintk("%s forget reply due to state\n", __func__);
1288                 goto out_forget_reply;
1289         }
1290
1291         /* Done processing layoutget. Set the layout stateid */
1292         pnfs_set_layout_stateid(lo, &res->stateid, false);
1293
1294         init_lseg(lo, lseg);
1295         lseg->pls_range = res->range;
1296         pnfs_get_lseg(lseg);
1297         pnfs_layout_insert_lseg(lo, lseg);
1298
1299         if (res->return_on_close) {
1300                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1301                 set_bit(NFS_LAYOUT_ROC, &lo->plh_flags);
1302         }
1303
1304         spin_unlock(&ino->i_lock);
1305         return lseg;
1306 out:
1307         return ERR_PTR(status);
1308
1309 out_forget_reply:
1310         spin_unlock(&ino->i_lock);
1311         lseg->pls_layout = lo;
1312         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1313         goto out;
1314 }
1315
1316 void
1317 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1318 {
1319         u64 rd_size = req->wb_bytes;
1320
1321         WARN_ON_ONCE(pgio->pg_lseg != NULL);
1322
1323         if (req->wb_offset != req->wb_pgbase) {
1324                 nfs_pageio_reset_read_mds(pgio);
1325                 return;
1326         }
1327
1328         if (pgio->pg_dreq == NULL)
1329                 rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
1330         else
1331                 rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1332
1333         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1334                                            req->wb_context,
1335                                            req_offset(req),
1336                                            rd_size,
1337                                            IOMODE_READ,
1338                                            GFP_KERNEL);
1339         /* If no lseg, fall back to read through mds */
1340         if (pgio->pg_lseg == NULL)
1341                 nfs_pageio_reset_read_mds(pgio);
1342
1343 }
1344 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
1345
1346 void
1347 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
1348                            struct nfs_page *req, u64 wb_size)
1349 {
1350         WARN_ON_ONCE(pgio->pg_lseg != NULL);
1351
1352         if (req->wb_offset != req->wb_pgbase) {
1353                 nfs_pageio_reset_write_mds(pgio);
1354                 return;
1355         }
1356
1357         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1358                                            req->wb_context,
1359                                            req_offset(req),
1360                                            wb_size,
1361                                            IOMODE_RW,
1362                                            GFP_NOFS);
1363         /* If no lseg, fall back to write through mds */
1364         if (pgio->pg_lseg == NULL)
1365                 nfs_pageio_reset_write_mds(pgio);
1366 }
1367 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
1368
1369 void
1370 pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
1371                       const struct nfs_pgio_completion_ops *compl_ops)
1372 {
1373         struct nfs_server *server = NFS_SERVER(inode);
1374         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
1375
1376         if (ld == NULL)
1377                 nfs_pageio_init_read(pgio, inode, compl_ops);
1378         else
1379                 nfs_pageio_init(pgio, inode, ld->pg_read_ops, compl_ops, server->rsize, 0);
1380 }
1381
1382 void
1383 pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode,
1384                        int ioflags,
1385                        const struct nfs_pgio_completion_ops *compl_ops)
1386 {
1387         struct nfs_server *server = NFS_SERVER(inode);
1388         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
1389
1390         if (ld == NULL)
1391                 nfs_pageio_init_write(pgio, inode, ioflags, compl_ops);
1392         else
1393                 nfs_pageio_init(pgio, inode, ld->pg_write_ops, compl_ops, server->wsize, ioflags);
1394 }
1395
1396 bool
1397 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
1398                      struct nfs_page *req)
1399 {
1400         if (pgio->pg_lseg == NULL)
1401                 return nfs_generic_pg_test(pgio, prev, req);
1402
1403         /*
1404          * Test if a nfs_page is fully contained in the pnfs_layout_range.
1405          * Note that this test makes several assumptions:
1406          * - that the previous nfs_page in the struct nfs_pageio_descriptor
1407          *   is known to lie within the range.
1408          *   - that the nfs_page being tested is known to be contiguous with the
1409          *   previous nfs_page.
1410          *   - Layout ranges are page aligned, so we only have to test the
1411          *   start offset of the request.
1412          *
1413          * Please also note that 'end_offset' is actually the offset of the
1414          * first byte that lies outside the pnfs_layout_range. FIXME?
1415          *
1416          */
1417         return req_offset(req) < end_offset(pgio->pg_lseg->pls_range.offset,
1418                                          pgio->pg_lseg->pls_range.length);
1419 }
1420 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
1421
1422 int pnfs_write_done_resend_to_mds(struct inode *inode,
1423                                 struct list_head *head,
1424                                 const struct nfs_pgio_completion_ops *compl_ops,
1425                                 struct nfs_direct_req *dreq)
1426 {
1427         struct nfs_pageio_descriptor pgio;
1428         LIST_HEAD(failed);
1429
1430         /* Resend all requests through the MDS */
1431         nfs_pageio_init_write(&pgio, inode, FLUSH_STABLE, compl_ops);
1432         pgio.pg_dreq = dreq;
1433         while (!list_empty(head)) {
1434                 struct nfs_page *req = nfs_list_entry(head->next);
1435
1436                 nfs_list_remove_request(req);
1437                 if (!nfs_pageio_add_request(&pgio, req))
1438                         nfs_list_add_request(req, &failed);
1439         }
1440         nfs_pageio_complete(&pgio);
1441
1442         if (!list_empty(&failed)) {
1443                 /* For some reason our attempt to resend pages. Mark the
1444                  * overall send request as having failed, and let
1445                  * nfs_writeback_release_full deal with the error.
1446                  */
1447                 list_move(&failed, head);
1448                 return -EIO;
1449         }
1450         return 0;
1451 }
1452 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
1453
1454 static void pnfs_ld_handle_write_error(struct nfs_write_data *data)
1455 {
1456         struct nfs_pgio_header *hdr = data->header;
1457
1458         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
1459         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
1460             PNFS_LAYOUTRET_ON_ERROR) {
1461                 clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(hdr->inode)->flags);
1462                 pnfs_return_layout(hdr->inode);
1463         }
1464         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
1465                 data->task.tk_status = pnfs_write_done_resend_to_mds(hdr->inode,
1466                                                         &hdr->pages,
1467                                                         hdr->completion_ops,
1468                                                         hdr->dreq);
1469 }
1470
1471 /*
1472  * Called by non rpc-based layout drivers
1473  */
1474 void pnfs_ld_write_done(struct nfs_write_data *data)
1475 {
1476         struct nfs_pgio_header *hdr = data->header;
1477
1478         if (!hdr->pnfs_error) {
1479                 pnfs_set_layoutcommit(data);
1480                 hdr->mds_ops->rpc_call_done(&data->task, data);
1481         } else
1482                 pnfs_ld_handle_write_error(data);
1483         hdr->mds_ops->rpc_release(data);
1484 }
1485 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
1486
1487 static void
1488 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
1489                 struct nfs_write_data *data)
1490 {
1491         struct nfs_pgio_header *hdr = data->header;
1492
1493         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1494                 list_splice_tail_init(&hdr->pages, &desc->pg_list);
1495                 nfs_pageio_reset_write_mds(desc);
1496                 desc->pg_recoalesce = 1;
1497         }
1498         nfs_writedata_release(data);
1499 }
1500
1501 static enum pnfs_try_status
1502 pnfs_try_to_write_data(struct nfs_write_data *wdata,
1503                         const struct rpc_call_ops *call_ops,
1504                         struct pnfs_layout_segment *lseg,
1505                         int how)
1506 {
1507         struct nfs_pgio_header *hdr = wdata->header;
1508         struct inode *inode = hdr->inode;
1509         enum pnfs_try_status trypnfs;
1510         struct nfs_server *nfss = NFS_SERVER(inode);
1511
1512         hdr->mds_ops = call_ops;
1513
1514         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
1515                 inode->i_ino, wdata->args.count, wdata->args.offset, how);
1516         trypnfs = nfss->pnfs_curr_ld->write_pagelist(wdata, how);
1517         if (trypnfs != PNFS_NOT_ATTEMPTED)
1518                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
1519         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
1520         return trypnfs;
1521 }
1522
1523 static void
1524 pnfs_do_multiple_writes(struct nfs_pageio_descriptor *desc, struct list_head *head, int how)
1525 {
1526         struct nfs_write_data *data;
1527         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
1528         struct pnfs_layout_segment *lseg = desc->pg_lseg;
1529
1530         desc->pg_lseg = NULL;
1531         while (!list_empty(head)) {
1532                 enum pnfs_try_status trypnfs;
1533
1534                 data = list_first_entry(head, struct nfs_write_data, list);
1535                 list_del_init(&data->list);
1536
1537                 trypnfs = pnfs_try_to_write_data(data, call_ops, lseg, how);
1538                 if (trypnfs == PNFS_NOT_ATTEMPTED)
1539                         pnfs_write_through_mds(desc, data);
1540         }
1541         pnfs_put_lseg(lseg);
1542 }
1543
1544 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
1545 {
1546         pnfs_put_lseg(hdr->lseg);
1547         nfs_writehdr_free(hdr);
1548 }
1549 EXPORT_SYMBOL_GPL(pnfs_writehdr_free);
1550
1551 int
1552 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1553 {
1554         struct nfs_write_header *whdr;
1555         struct nfs_pgio_header *hdr;
1556         int ret;
1557
1558         whdr = nfs_writehdr_alloc();
1559         if (!whdr) {
1560                 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1561                 pnfs_put_lseg(desc->pg_lseg);
1562                 desc->pg_lseg = NULL;
1563                 return -ENOMEM;
1564         }
1565         hdr = &whdr->header;
1566         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
1567         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
1568         atomic_inc(&hdr->refcnt);
1569         ret = nfs_generic_flush(desc, hdr);
1570         if (ret != 0) {
1571                 pnfs_put_lseg(desc->pg_lseg);
1572                 desc->pg_lseg = NULL;
1573         } else
1574                 pnfs_do_multiple_writes(desc, &hdr->rpc_list, desc->pg_ioflags);
1575         if (atomic_dec_and_test(&hdr->refcnt))
1576                 hdr->completion_ops->completion(hdr);
1577         return ret;
1578 }
1579 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
1580
1581 int pnfs_read_done_resend_to_mds(struct inode *inode,
1582                                 struct list_head *head,
1583                                 const struct nfs_pgio_completion_ops *compl_ops,
1584                                 struct nfs_direct_req *dreq)
1585 {
1586         struct nfs_pageio_descriptor pgio;
1587         LIST_HEAD(failed);
1588
1589         /* Resend all requests through the MDS */
1590         nfs_pageio_init_read(&pgio, inode, compl_ops);
1591         pgio.pg_dreq = dreq;
1592         while (!list_empty(head)) {
1593                 struct nfs_page *req = nfs_list_entry(head->next);
1594
1595                 nfs_list_remove_request(req);
1596                 if (!nfs_pageio_add_request(&pgio, req))
1597                         nfs_list_add_request(req, &failed);
1598         }
1599         nfs_pageio_complete(&pgio);
1600
1601         if (!list_empty(&failed)) {
1602                 list_move(&failed, head);
1603                 return -EIO;
1604         }
1605         return 0;
1606 }
1607 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
1608
1609 static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
1610 {
1611         struct nfs_pgio_header *hdr = data->header;
1612
1613         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
1614         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
1615             PNFS_LAYOUTRET_ON_ERROR) {
1616                 clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(hdr->inode)->flags);
1617                 pnfs_return_layout(hdr->inode);
1618         }
1619         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
1620                 data->task.tk_status = pnfs_read_done_resend_to_mds(hdr->inode,
1621                                                         &hdr->pages,
1622                                                         hdr->completion_ops,
1623                                                         hdr->dreq);
1624 }
1625
1626 /*
1627  * Called by non rpc-based layout drivers
1628  */
1629 void pnfs_ld_read_done(struct nfs_read_data *data)
1630 {
1631         struct nfs_pgio_header *hdr = data->header;
1632
1633         if (likely(!hdr->pnfs_error)) {
1634                 __nfs4_read_done_cb(data);
1635                 hdr->mds_ops->rpc_call_done(&data->task, data);
1636         } else
1637                 pnfs_ld_handle_read_error(data);
1638         hdr->mds_ops->rpc_release(data);
1639 }
1640 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
1641
1642 static void
1643 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
1644                 struct nfs_read_data *data)
1645 {
1646         struct nfs_pgio_header *hdr = data->header;
1647
1648         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1649                 list_splice_tail_init(&hdr->pages, &desc->pg_list);
1650                 nfs_pageio_reset_read_mds(desc);
1651                 desc->pg_recoalesce = 1;
1652         }
1653         nfs_readdata_release(data);
1654 }
1655
1656 /*
1657  * Call the appropriate parallel I/O subsystem read function.
1658  */
1659 static enum pnfs_try_status
1660 pnfs_try_to_read_data(struct nfs_read_data *rdata,
1661                        const struct rpc_call_ops *call_ops,
1662                        struct pnfs_layout_segment *lseg)
1663 {
1664         struct nfs_pgio_header *hdr = rdata->header;
1665         struct inode *inode = hdr->inode;
1666         struct nfs_server *nfss = NFS_SERVER(inode);
1667         enum pnfs_try_status trypnfs;
1668
1669         hdr->mds_ops = call_ops;
1670
1671         dprintk("%s: Reading ino:%lu %u@%llu\n",
1672                 __func__, inode->i_ino, rdata->args.count, rdata->args.offset);
1673
1674         trypnfs = nfss->pnfs_curr_ld->read_pagelist(rdata);
1675         if (trypnfs != PNFS_NOT_ATTEMPTED)
1676                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
1677         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
1678         return trypnfs;
1679 }
1680
1681 static void
1682 pnfs_do_multiple_reads(struct nfs_pageio_descriptor *desc, struct list_head *head)
1683 {
1684         struct nfs_read_data *data;
1685         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
1686         struct pnfs_layout_segment *lseg = desc->pg_lseg;
1687
1688         desc->pg_lseg = NULL;
1689         while (!list_empty(head)) {
1690                 enum pnfs_try_status trypnfs;
1691
1692                 data = list_first_entry(head, struct nfs_read_data, list);
1693                 list_del_init(&data->list);
1694
1695                 trypnfs = pnfs_try_to_read_data(data, call_ops, lseg);
1696                 if (trypnfs == PNFS_NOT_ATTEMPTED)
1697                         pnfs_read_through_mds(desc, data);
1698         }
1699         pnfs_put_lseg(lseg);
1700 }
1701
1702 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
1703 {
1704         pnfs_put_lseg(hdr->lseg);
1705         nfs_readhdr_free(hdr);
1706 }
1707 EXPORT_SYMBOL_GPL(pnfs_readhdr_free);
1708
1709 int
1710 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
1711 {
1712         struct nfs_read_header *rhdr;
1713         struct nfs_pgio_header *hdr;
1714         int ret;
1715
1716         rhdr = nfs_readhdr_alloc();
1717         if (!rhdr) {
1718                 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1719                 ret = -ENOMEM;
1720                 pnfs_put_lseg(desc->pg_lseg);
1721                 desc->pg_lseg = NULL;
1722                 return ret;
1723         }
1724         hdr = &rhdr->header;
1725         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
1726         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
1727         atomic_inc(&hdr->refcnt);
1728         ret = nfs_generic_pagein(desc, hdr);
1729         if (ret != 0) {
1730                 pnfs_put_lseg(desc->pg_lseg);
1731                 desc->pg_lseg = NULL;
1732         } else
1733                 pnfs_do_multiple_reads(desc, &hdr->rpc_list);
1734         if (atomic_dec_and_test(&hdr->refcnt))
1735                 hdr->completion_ops->completion(hdr);
1736         return ret;
1737 }
1738 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
1739
1740 /*
1741  * There can be multiple RW segments.
1742  */
1743 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
1744 {
1745         struct pnfs_layout_segment *lseg;
1746
1747         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
1748                 if (lseg->pls_range.iomode == IOMODE_RW &&
1749                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1750                         list_add(&lseg->pls_lc_list, listp);
1751         }
1752 }
1753
1754 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
1755 {
1756         struct pnfs_layout_segment *lseg, *tmp;
1757         unsigned long *bitlock = &NFS_I(inode)->flags;
1758
1759         /* Matched by references in pnfs_set_layoutcommit */
1760         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
1761                 list_del_init(&lseg->pls_lc_list);
1762                 pnfs_put_lseg(lseg);
1763         }
1764
1765         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
1766         smp_mb__after_clear_bit();
1767         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
1768 }
1769
1770 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
1771 {
1772         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
1773 }
1774 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
1775
1776 void
1777 pnfs_set_layoutcommit(struct nfs_write_data *wdata)
1778 {
1779         struct nfs_pgio_header *hdr = wdata->header;
1780         struct inode *inode = hdr->inode;
1781         struct nfs_inode *nfsi = NFS_I(inode);
1782         loff_t end_pos = wdata->mds_offset + wdata->res.count;
1783         bool mark_as_dirty = false;
1784
1785         spin_lock(&inode->i_lock);
1786         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
1787                 mark_as_dirty = true;
1788                 dprintk("%s: Set layoutcommit for inode %lu ",
1789                         __func__, inode->i_ino);
1790         }
1791         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &hdr->lseg->pls_flags)) {
1792                 /* references matched in nfs4_layoutcommit_release */
1793                 pnfs_get_lseg(hdr->lseg);
1794         }
1795         if (end_pos > nfsi->layout->plh_lwb)
1796                 nfsi->layout->plh_lwb = end_pos;
1797         spin_unlock(&inode->i_lock);
1798         dprintk("%s: lseg %p end_pos %llu\n",
1799                 __func__, hdr->lseg, nfsi->layout->plh_lwb);
1800
1801         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
1802          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
1803         if (mark_as_dirty)
1804                 mark_inode_dirty_sync(inode);
1805 }
1806 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
1807
1808 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
1809 {
1810         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
1811
1812         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
1813                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
1814         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
1815 }
1816
1817 /*
1818  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
1819  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
1820  * data to disk to allow the server to recover the data if it crashes.
1821  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
1822  * is off, and a COMMIT is sent to a data server, or
1823  * if WRITEs to a data server return NFS_DATA_SYNC.
1824  */
1825 int
1826 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
1827 {
1828         struct nfs4_layoutcommit_data *data;
1829         struct nfs_inode *nfsi = NFS_I(inode);
1830         loff_t end_pos;
1831         int status = 0;
1832
1833         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
1834
1835         if (!test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1836                 return 0;
1837
1838         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
1839         data = kzalloc(sizeof(*data), GFP_NOFS);
1840         if (!data) {
1841                 status = -ENOMEM;
1842                 goto out;
1843         }
1844
1845         if (!test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1846                 goto out_free;
1847
1848         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
1849                 if (!sync) {
1850                         status = -EAGAIN;
1851                         goto out_free;
1852                 }
1853                 status = wait_on_bit_lock(&nfsi->flags, NFS_INO_LAYOUTCOMMITTING,
1854                                         nfs_wait_bit_killable, TASK_KILLABLE);
1855                 if (status)
1856                         goto out_free;
1857         }
1858
1859         INIT_LIST_HEAD(&data->lseg_list);
1860         spin_lock(&inode->i_lock);
1861         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
1862                 clear_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags);
1863                 spin_unlock(&inode->i_lock);
1864                 wake_up_bit(&nfsi->flags, NFS_INO_LAYOUTCOMMITTING);
1865                 goto out_free;
1866         }
1867
1868         pnfs_list_write_lseg(inode, &data->lseg_list);
1869
1870         end_pos = nfsi->layout->plh_lwb;
1871         nfsi->layout->plh_lwb = 0;
1872
1873         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
1874         spin_unlock(&inode->i_lock);
1875
1876         data->args.inode = inode;
1877         data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
1878         nfs_fattr_init(&data->fattr);
1879         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
1880         data->res.fattr = &data->fattr;
1881         data->args.lastbytewritten = end_pos - 1;
1882         data->res.server = NFS_SERVER(inode);
1883
1884         status = nfs4_proc_layoutcommit(data, sync);
1885 out:
1886         if (status)
1887                 mark_inode_dirty_sync(inode);
1888         dprintk("<-- %s status %d\n", __func__, status);
1889         return status;
1890 out_free:
1891         kfree(data);
1892         goto out;
1893 }
1894
1895 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
1896 {
1897         struct nfs4_threshold *thp;
1898
1899         thp = kzalloc(sizeof(*thp), GFP_NOFS);
1900         if (!thp) {
1901                 dprintk("%s mdsthreshold allocation failed\n", __func__);
1902                 return NULL;
1903         }
1904         return thp;
1905 }