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 <linux/sort.h>
34 #include "internal.h"
35 #include "pnfs.h"
36 #include "iostat.h"
37 #include "nfs4trace.h"
38 #include "delegation.h"
39 #include "nfs42.h"
40 #include "nfs4_fs.h"
41 
42 #define NFSDBG_FACILITY		NFSDBG_PNFS
43 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
44 
45 /* Locking:
46  *
47  * pnfs_spinlock:
48  *      protects pnfs_modules_tbl.
49  */
50 static DEFINE_SPINLOCK(pnfs_spinlock);
51 
52 /*
53  * pnfs_modules_tbl holds all pnfs modules
54  */
55 static LIST_HEAD(pnfs_modules_tbl);
56 
57 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
58 static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
59 		struct list_head *free_me,
60 		const struct pnfs_layout_range *range,
61 		u32 seq);
62 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
63 		                struct list_head *tmp_list);
64 
65 /* Return the registered pnfs layout driver module matching given id */
66 static struct pnfs_layoutdriver_type *
find_pnfs_driver_locked(u32 id)67 find_pnfs_driver_locked(u32 id)
68 {
69 	struct pnfs_layoutdriver_type *local;
70 
71 	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
72 		if (local->id == id)
73 			goto out;
74 	local = NULL;
75 out:
76 	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
77 	return local;
78 }
79 
80 static struct pnfs_layoutdriver_type *
find_pnfs_driver(u32 id)81 find_pnfs_driver(u32 id)
82 {
83 	struct pnfs_layoutdriver_type *local;
84 
85 	spin_lock(&pnfs_spinlock);
86 	local = find_pnfs_driver_locked(id);
87 	if (local != NULL && !try_module_get(local->owner)) {
88 		dprintk("%s: Could not grab reference on module\n", __func__);
89 		local = NULL;
90 	}
91 	spin_unlock(&pnfs_spinlock);
92 	return local;
93 }
94 
pnfs_find_layoutdriver(u32 id)95 const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
96 {
97 	return find_pnfs_driver(id);
98 }
99 
pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type * ld)100 void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
101 {
102 	if (ld)
103 		module_put(ld->owner);
104 }
105 
106 void
unset_pnfs_layoutdriver(struct nfs_server * nfss)107 unset_pnfs_layoutdriver(struct nfs_server *nfss)
108 {
109 	if (nfss->pnfs_curr_ld) {
110 		if (nfss->pnfs_curr_ld->clear_layoutdriver)
111 			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
112 		/* Decrement the MDS count. Purge the deviceid cache if zero */
113 		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
114 			nfs4_deviceid_purge_client(nfss->nfs_client);
115 		module_put(nfss->pnfs_curr_ld->owner);
116 	}
117 	nfss->pnfs_curr_ld = NULL;
118 }
119 
120 /*
121  * When the server sends a list of layout types, we choose one in the order
122  * given in the list below.
123  *
124  * FIXME: should this list be configurable in some fashion? module param?
125  * 	  mount option? something else?
126  */
127 static const u32 ld_prefs[] = {
128 	LAYOUT_SCSI,
129 	LAYOUT_BLOCK_VOLUME,
130 	LAYOUT_OSD2_OBJECTS,
131 	LAYOUT_FLEX_FILES,
132 	LAYOUT_NFSV4_1_FILES,
133 	0
134 };
135 
136 static int
ld_cmp(const void * e1,const void * e2)137 ld_cmp(const void *e1, const void *e2)
138 {
139 	u32 ld1 = *((u32 *)e1);
140 	u32 ld2 = *((u32 *)e2);
141 	int i;
142 
143 	for (i = 0; ld_prefs[i] != 0; i++) {
144 		if (ld1 == ld_prefs[i])
145 			return -1;
146 
147 		if (ld2 == ld_prefs[i])
148 			return 1;
149 	}
150 	return 0;
151 }
152 
153 /*
154  * Try to set the server's pnfs module to the pnfs layout type specified by id.
155  * Currently only one pNFS layout driver per filesystem is supported.
156  *
157  * @ids array of layout types supported by MDS.
158  */
159 void
set_pnfs_layoutdriver(struct nfs_server * server,const struct nfs_fh * mntfh,struct nfs_fsinfo * fsinfo)160 set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
161 		      struct nfs_fsinfo *fsinfo)
162 {
163 	struct pnfs_layoutdriver_type *ld_type = NULL;
164 	u32 id;
165 	int i;
166 
167 	if (fsinfo->nlayouttypes == 0)
168 		goto out_no_driver;
169 	if (!(server->nfs_client->cl_exchange_flags &
170 		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
171 		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
172 			__func__, server->nfs_client->cl_exchange_flags);
173 		goto out_no_driver;
174 	}
175 
176 	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
177 		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
178 
179 	for (i = 0; i < fsinfo->nlayouttypes; i++) {
180 		id = fsinfo->layouttype[i];
181 		ld_type = find_pnfs_driver(id);
182 		if (!ld_type) {
183 			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
184 					id);
185 			ld_type = find_pnfs_driver(id);
186 		}
187 		if (ld_type)
188 			break;
189 	}
190 
191 	if (!ld_type) {
192 		dprintk("%s: No pNFS module found!\n", __func__);
193 		goto out_no_driver;
194 	}
195 
196 	server->pnfs_curr_ld = ld_type;
197 	if (ld_type->set_layoutdriver
198 	    && ld_type->set_layoutdriver(server, mntfh)) {
199 		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
200 			"driver %u.\n", __func__, id);
201 		module_put(ld_type->owner);
202 		goto out_no_driver;
203 	}
204 	/* Bump the MDS count */
205 	atomic_inc(&server->nfs_client->cl_mds_count);
206 
207 	dprintk("%s: pNFS module for %u set\n", __func__, id);
208 	return;
209 
210 out_no_driver:
211 	dprintk("%s: Using NFSv4 I/O\n", __func__);
212 	server->pnfs_curr_ld = NULL;
213 }
214 
215 int
pnfs_register_layoutdriver(struct pnfs_layoutdriver_type * ld_type)216 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
217 {
218 	int status = -EINVAL;
219 	struct pnfs_layoutdriver_type *tmp;
220 
221 	if (ld_type->id == 0) {
222 		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
223 		return status;
224 	}
225 	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
226 		printk(KERN_ERR "NFS: %s Layout driver must provide "
227 		       "alloc_lseg and free_lseg.\n", __func__);
228 		return status;
229 	}
230 
231 	spin_lock(&pnfs_spinlock);
232 	tmp = find_pnfs_driver_locked(ld_type->id);
233 	if (!tmp) {
234 		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
235 		status = 0;
236 		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
237 			ld_type->name);
238 	} else {
239 		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
240 			__func__, ld_type->id);
241 	}
242 	spin_unlock(&pnfs_spinlock);
243 
244 	return status;
245 }
246 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
247 
248 void
pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type * ld_type)249 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
250 {
251 	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
252 	spin_lock(&pnfs_spinlock);
253 	list_del(&ld_type->pnfs_tblid);
254 	spin_unlock(&pnfs_spinlock);
255 }
256 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
257 
258 /*
259  * pNFS client layout cache
260  */
261 
262 /* Need to hold i_lock if caller does not already hold reference */
263 void
pnfs_get_layout_hdr(struct pnfs_layout_hdr * lo)264 pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
265 {
266 	refcount_inc(&lo->plh_refcount);
267 }
268 
269 static struct pnfs_layout_hdr *
pnfs_alloc_layout_hdr(struct inode * ino,gfp_t gfp_flags)270 pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
271 {
272 	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
273 	return ld->alloc_layout_hdr(ino, gfp_flags);
274 }
275 
276 static void
pnfs_free_layout_hdr(struct pnfs_layout_hdr * lo)277 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
278 {
279 	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
280 	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
281 
282 	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
283 		struct nfs_client *clp = server->nfs_client;
284 
285 		spin_lock(&clp->cl_lock);
286 		list_del_rcu(&lo->plh_layouts);
287 		spin_unlock(&clp->cl_lock);
288 	}
289 	put_cred(lo->plh_lc_cred);
290 	return ld->free_layout_hdr(lo);
291 }
292 
293 static void
pnfs_detach_layout_hdr(struct pnfs_layout_hdr * lo)294 pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
295 {
296 	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
297 	dprintk("%s: freeing layout cache %p\n", __func__, lo);
298 	nfsi->layout = NULL;
299 	/* Reset MDS Threshold I/O counters */
300 	nfsi->write_io = 0;
301 	nfsi->read_io = 0;
302 }
303 
304 void
pnfs_put_layout_hdr(struct pnfs_layout_hdr * lo)305 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
306 {
307 	struct inode *inode;
308 	unsigned long i_state;
309 
310 	if (!lo)
311 		return;
312 	inode = lo->plh_inode;
313 	pnfs_layoutreturn_before_put_layout_hdr(lo);
314 
315 	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
316 		if (!list_empty(&lo->plh_segs))
317 			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
318 		pnfs_detach_layout_hdr(lo);
319 		i_state = inode->i_state;
320 		spin_unlock(&inode->i_lock);
321 		pnfs_free_layout_hdr(lo);
322 		/* Notify pnfs_destroy_layout_final() that we're done */
323 		if (i_state & (I_FREEING | I_CLEAR))
324 			wake_up_var(lo);
325 	}
326 }
327 
328 static struct inode *
pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr * lo)329 pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
330 {
331 	struct inode *inode = igrab(lo->plh_inode);
332 	if (inode)
333 		return inode;
334 	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
335 	return NULL;
336 }
337 
338 /*
339  * Compare 2 layout stateid sequence ids, to see which is newer,
340  * taking into account wraparound issues.
341  */
pnfs_seqid_is_newer(u32 s1,u32 s2)342 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
343 {
344 	return (s32)(s1 - s2) > 0;
345 }
346 
pnfs_barrier_update(struct pnfs_layout_hdr * lo,u32 newseq)347 static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
348 {
349 	if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
350 		lo->plh_barrier = newseq;
351 }
352 
353 static void
pnfs_set_plh_return_info(struct pnfs_layout_hdr * lo,enum pnfs_iomode iomode,u32 seq)354 pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
355 			 u32 seq)
356 {
357 	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
358 		iomode = IOMODE_ANY;
359 	lo->plh_return_iomode = iomode;
360 	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
361 	/*
362 	 * We must set lo->plh_return_seq to avoid livelocks with
363 	 * pnfs_layout_need_return()
364 	 */
365 	if (seq == 0)
366 		seq = be32_to_cpu(lo->plh_stateid.seqid);
367 	if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
368 		lo->plh_return_seq = seq;
369 	pnfs_barrier_update(lo, seq);
370 }
371 
372 static void
pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr * lo)373 pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
374 {
375 	struct pnfs_layout_segment *lseg;
376 	lo->plh_return_iomode = 0;
377 	lo->plh_return_seq = 0;
378 	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
379 	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
380 		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
381 			continue;
382 		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
383 	}
384 }
385 
pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr * lo)386 static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
387 {
388 	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
389 	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
390 	smp_mb__after_atomic();
391 	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
392 	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
393 }
394 
395 static void
pnfs_clear_lseg_state(struct pnfs_layout_segment * lseg,struct list_head * free_me)396 pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
397 		struct list_head *free_me)
398 {
399 	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
400 	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
401 	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
402 		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
403 	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
404 		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
405 }
406 
407 /*
408  * Update the seqid of a layout stateid after receiving
409  * NFS4ERR_OLD_STATEID
410  */
nfs4_layout_refresh_old_stateid(nfs4_stateid * dst,struct pnfs_layout_range * dst_range,struct inode * inode)411 bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
412 		struct pnfs_layout_range *dst_range,
413 		struct inode *inode)
414 {
415 	struct pnfs_layout_hdr *lo;
416 	struct pnfs_layout_range range = {
417 		.iomode = IOMODE_ANY,
418 		.offset = 0,
419 		.length = NFS4_MAX_UINT64,
420 	};
421 	bool ret = false;
422 	LIST_HEAD(head);
423 	int err;
424 
425 	spin_lock(&inode->i_lock);
426 	lo = NFS_I(inode)->layout;
427 	if (lo &&  pnfs_layout_is_valid(lo) &&
428 	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
429 		/* Is our call using the most recent seqid? If so, bump it */
430 		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
431 			nfs4_stateid_seqid_inc(dst);
432 			ret = true;
433 			goto out;
434 		}
435 		/* Try to update the seqid to the most recent */
436 		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
437 		if (err != -EBUSY) {
438 			dst->seqid = lo->plh_stateid.seqid;
439 			*dst_range = range;
440 			ret = true;
441 		}
442 	}
443 out:
444 	spin_unlock(&inode->i_lock);
445 	pnfs_free_lseg_list(&head);
446 	return ret;
447 }
448 
449 /*
450  * Mark a pnfs_layout_hdr and all associated layout segments as invalid
451  *
452  * In order to continue using the pnfs_layout_hdr, a full recovery
453  * is required.
454  * Note that caller must hold inode->i_lock.
455  */
456 int
pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr * lo,struct list_head * lseg_list)457 pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
458 		struct list_head *lseg_list)
459 {
460 	struct pnfs_layout_range range = {
461 		.iomode = IOMODE_ANY,
462 		.offset = 0,
463 		.length = NFS4_MAX_UINT64,
464 	};
465 	struct pnfs_layout_segment *lseg, *next;
466 
467 	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
468 	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
469 		pnfs_clear_lseg_state(lseg, lseg_list);
470 	pnfs_clear_layoutreturn_info(lo);
471 	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
472 	set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
473 	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
474 	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
475 		pnfs_clear_layoutreturn_waitbit(lo);
476 	return !list_empty(&lo->plh_segs);
477 }
478 
479 static int
pnfs_iomode_to_fail_bit(u32 iomode)480 pnfs_iomode_to_fail_bit(u32 iomode)
481 {
482 	return iomode == IOMODE_RW ?
483 		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
484 }
485 
486 static void
pnfs_layout_set_fail_bit(struct pnfs_layout_hdr * lo,int fail_bit)487 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
488 {
489 	lo->plh_retry_timestamp = jiffies;
490 	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
491 		refcount_inc(&lo->plh_refcount);
492 }
493 
494 static void
pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr * lo,int fail_bit)495 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
496 {
497 	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
498 		refcount_dec(&lo->plh_refcount);
499 }
500 
501 static void
pnfs_layout_io_set_failed(struct pnfs_layout_hdr * lo,u32 iomode)502 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
503 {
504 	struct inode *inode = lo->plh_inode;
505 	struct pnfs_layout_range range = {
506 		.iomode = iomode,
507 		.offset = 0,
508 		.length = NFS4_MAX_UINT64,
509 	};
510 	LIST_HEAD(head);
511 
512 	spin_lock(&inode->i_lock);
513 	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
514 	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
515 	spin_unlock(&inode->i_lock);
516 	pnfs_free_lseg_list(&head);
517 	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
518 			iomode == IOMODE_RW ?  "RW" : "READ");
519 }
520 
521 static bool
pnfs_layout_io_test_failed(struct pnfs_layout_hdr * lo,u32 iomode)522 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
523 {
524 	unsigned long start, end;
525 	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
526 
527 	if (test_bit(fail_bit, &lo->plh_flags) == 0)
528 		return false;
529 	end = jiffies;
530 	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
531 	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
532 		/* It is time to retry the failed layoutgets */
533 		pnfs_layout_clear_fail_bit(lo, fail_bit);
534 		return false;
535 	}
536 	return true;
537 }
538 
539 static void
pnfs_init_lseg(struct pnfs_layout_hdr * lo,struct pnfs_layout_segment * lseg,const struct pnfs_layout_range * range,const nfs4_stateid * stateid)540 pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
541 		const struct pnfs_layout_range *range,
542 		const nfs4_stateid *stateid)
543 {
544 	INIT_LIST_HEAD(&lseg->pls_list);
545 	INIT_LIST_HEAD(&lseg->pls_lc_list);
546 	INIT_LIST_HEAD(&lseg->pls_commits);
547 	refcount_set(&lseg->pls_refcount, 1);
548 	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
549 	lseg->pls_layout = lo;
550 	lseg->pls_range = *range;
551 	lseg->pls_seq = be32_to_cpu(stateid->seqid);
552 }
553 
pnfs_free_lseg(struct pnfs_layout_segment * lseg)554 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
555 {
556 	if (lseg != NULL) {
557 		struct inode *inode = lseg->pls_layout->plh_inode;
558 		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
559 	}
560 }
561 
562 static void
pnfs_layout_remove_lseg(struct pnfs_layout_hdr * lo,struct pnfs_layout_segment * lseg)563 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
564 		struct pnfs_layout_segment *lseg)
565 {
566 	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
567 	list_del_init(&lseg->pls_list);
568 	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
569 	refcount_dec(&lo->plh_refcount);
570 	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
571 		return;
572 	if (list_empty(&lo->plh_segs) &&
573 	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
574 	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
575 		if (atomic_read(&lo->plh_outstanding) == 0)
576 			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
577 		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
578 	}
579 }
580 
581 static bool
pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr * lo,struct pnfs_layout_segment * lseg)582 pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
583 		struct pnfs_layout_segment *lseg)
584 {
585 	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
586 	    pnfs_layout_is_valid(lo)) {
587 		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
588 		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
589 		return true;
590 	}
591 	return false;
592 }
593 
594 void
pnfs_put_lseg(struct pnfs_layout_segment * lseg)595 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
596 {
597 	struct pnfs_layout_hdr *lo;
598 	struct inode *inode;
599 
600 	if (!lseg)
601 		return;
602 
603 	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
604 		refcount_read(&lseg->pls_refcount),
605 		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
606 
607 	lo = lseg->pls_layout;
608 	inode = lo->plh_inode;
609 
610 	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
611 		pnfs_get_layout_hdr(lo);
612 		pnfs_layout_remove_lseg(lo, lseg);
613 		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
614 			lseg = NULL;
615 		spin_unlock(&inode->i_lock);
616 		pnfs_free_lseg(lseg);
617 		pnfs_put_layout_hdr(lo);
618 	}
619 }
620 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
621 
622 /*
623  * is l2 fully contained in l1?
624  *   start1                             end1
625  *   [----------------------------------)
626  *           start2           end2
627  *           [----------------)
628  */
629 static bool
pnfs_lseg_range_contained(const struct pnfs_layout_range * l1,const struct pnfs_layout_range * l2)630 pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
631 		 const struct pnfs_layout_range *l2)
632 {
633 	u64 start1 = l1->offset;
634 	u64 end1 = pnfs_end_offset(start1, l1->length);
635 	u64 start2 = l2->offset;
636 	u64 end2 = pnfs_end_offset(start2, l2->length);
637 
638 	return (start1 <= start2) && (end1 >= end2);
639 }
640 
pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment * lseg,struct list_head * tmp_list)641 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
642 		struct list_head *tmp_list)
643 {
644 	if (!refcount_dec_and_test(&lseg->pls_refcount))
645 		return false;
646 	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
647 	list_add(&lseg->pls_list, tmp_list);
648 	return true;
649 }
650 
651 /* Returns 1 if lseg is removed from list, 0 otherwise */
mark_lseg_invalid(struct pnfs_layout_segment * lseg,struct list_head * tmp_list)652 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
653 			     struct list_head *tmp_list)
654 {
655 	int rv = 0;
656 
657 	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
658 		/* Remove the reference keeping the lseg in the
659 		 * list.  It will now be removed when all
660 		 * outstanding io is finished.
661 		 */
662 		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
663 			refcount_read(&lseg->pls_refcount));
664 		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
665 			rv = 1;
666 	}
667 	return rv;
668 }
669 
670 static bool
pnfs_should_free_range(const struct pnfs_layout_range * lseg_range,const struct pnfs_layout_range * recall_range)671 pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
672 		 const struct pnfs_layout_range *recall_range)
673 {
674 	return (recall_range->iomode == IOMODE_ANY ||
675 		lseg_range->iomode == recall_range->iomode) &&
676 	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
677 }
678 
679 static bool
pnfs_match_lseg_recall(const struct pnfs_layout_segment * lseg,const struct pnfs_layout_range * recall_range,u32 seq)680 pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
681 		const struct pnfs_layout_range *recall_range,
682 		u32 seq)
683 {
684 	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
685 		return false;
686 	if (recall_range == NULL)
687 		return true;
688 	return pnfs_should_free_range(&lseg->pls_range, recall_range);
689 }
690 
691 /**
692  * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
693  * @lo: layout header containing the lsegs
694  * @tmp_list: list head where doomed lsegs should go
695  * @recall_range: optional recall range argument to match (may be NULL)
696  * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
697  *
698  * Walk the list of lsegs in the layout header, and tear down any that should
699  * be destroyed. If "recall_range" is specified then the segment must match
700  * that range. If "seq" is non-zero, then only match segments that were handed
701  * out at or before that sequence.
702  *
703  * Returns number of matching invalid lsegs remaining in list after scanning
704  * it and purging them.
705  */
706 int
pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr * lo,struct list_head * tmp_list,const struct pnfs_layout_range * recall_range,u32 seq)707 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
708 			    struct list_head *tmp_list,
709 			    const struct pnfs_layout_range *recall_range,
710 			    u32 seq)
711 {
712 	struct pnfs_layout_segment *lseg, *next;
713 	int remaining = 0;
714 
715 	dprintk("%s:Begin lo %p\n", __func__, lo);
716 
717 	if (list_empty(&lo->plh_segs))
718 		return 0;
719 	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
720 		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
721 			dprintk("%s: freeing lseg %p iomode %d seq %u "
722 				"offset %llu length %llu\n", __func__,
723 				lseg, lseg->pls_range.iomode, lseg->pls_seq,
724 				lseg->pls_range.offset, lseg->pls_range.length);
725 			if (!mark_lseg_invalid(lseg, tmp_list))
726 				remaining++;
727 		}
728 	dprintk("%s:Return %i\n", __func__, remaining);
729 	return remaining;
730 }
731 
732 static void
pnfs_free_returned_lsegs(struct pnfs_layout_hdr * lo,struct list_head * free_me,const struct pnfs_layout_range * range,u32 seq)733 pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
734 		struct list_head *free_me,
735 		const struct pnfs_layout_range *range,
736 		u32 seq)
737 {
738 	struct pnfs_layout_segment *lseg, *next;
739 
740 	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
741 		if (pnfs_match_lseg_recall(lseg, range, seq))
742 			list_move_tail(&lseg->pls_list, free_me);
743 	}
744 }
745 
746 /* note free_me must contain lsegs from a single layout_hdr */
747 void
pnfs_free_lseg_list(struct list_head * free_me)748 pnfs_free_lseg_list(struct list_head *free_me)
749 {
750 	struct pnfs_layout_segment *lseg, *tmp;
751 
752 	if (list_empty(free_me))
753 		return;
754 
755 	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
756 		list_del(&lseg->pls_list);
757 		pnfs_free_lseg(lseg);
758 	}
759 }
760 
__pnfs_destroy_layout(struct nfs_inode * nfsi)761 static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
762 {
763 	struct pnfs_layout_hdr *lo;
764 	LIST_HEAD(tmp_list);
765 
766 	spin_lock(&nfsi->vfs_inode.i_lock);
767 	lo = nfsi->layout;
768 	if (lo) {
769 		pnfs_get_layout_hdr(lo);
770 		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
771 		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
772 		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
773 		spin_unlock(&nfsi->vfs_inode.i_lock);
774 		pnfs_free_lseg_list(&tmp_list);
775 		nfs_commit_inode(&nfsi->vfs_inode, 0);
776 		pnfs_put_layout_hdr(lo);
777 	} else
778 		spin_unlock(&nfsi->vfs_inode.i_lock);
779 	return lo;
780 }
781 
pnfs_destroy_layout(struct nfs_inode * nfsi)782 void pnfs_destroy_layout(struct nfs_inode *nfsi)
783 {
784 	__pnfs_destroy_layout(nfsi);
785 }
786 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
787 
pnfs_layout_removed(struct nfs_inode * nfsi,struct pnfs_layout_hdr * lo)788 static bool pnfs_layout_removed(struct nfs_inode *nfsi,
789 				struct pnfs_layout_hdr *lo)
790 {
791 	bool ret;
792 
793 	spin_lock(&nfsi->vfs_inode.i_lock);
794 	ret = nfsi->layout != lo;
795 	spin_unlock(&nfsi->vfs_inode.i_lock);
796 	return ret;
797 }
798 
pnfs_destroy_layout_final(struct nfs_inode * nfsi)799 void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
800 {
801 	struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
802 
803 	if (lo)
804 		wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
805 }
806 
807 static bool
pnfs_layout_add_bulk_destroy_list(struct inode * inode,struct list_head * layout_list)808 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
809 		struct list_head *layout_list)
810 {
811 	struct pnfs_layout_hdr *lo;
812 	bool ret = false;
813 
814 	spin_lock(&inode->i_lock);
815 	lo = NFS_I(inode)->layout;
816 	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
817 		pnfs_get_layout_hdr(lo);
818 		list_add(&lo->plh_bulk_destroy, layout_list);
819 		ret = true;
820 	}
821 	spin_unlock(&inode->i_lock);
822 	return ret;
823 }
824 
825 /* Caller must hold rcu_read_lock and clp->cl_lock */
826 static int
pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client * clp,struct nfs_server * server,struct list_head * layout_list)827 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
828 		struct nfs_server *server,
829 		struct list_head *layout_list)
830 	__must_hold(&clp->cl_lock)
831 	__must_hold(RCU)
832 {
833 	struct pnfs_layout_hdr *lo, *next;
834 	struct inode *inode;
835 
836 	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
837 		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
838 		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
839 		    !list_empty(&lo->plh_bulk_destroy))
840 			continue;
841 		/* If the sb is being destroyed, just bail */
842 		if (!nfs_sb_active(server->super))
843 			break;
844 		inode = pnfs_grab_inode_layout_hdr(lo);
845 		if (inode != NULL) {
846 			if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
847 				list_del_rcu(&lo->plh_layouts);
848 			if (pnfs_layout_add_bulk_destroy_list(inode,
849 						layout_list))
850 				continue;
851 			rcu_read_unlock();
852 			spin_unlock(&clp->cl_lock);
853 			iput(inode);
854 		} else {
855 			rcu_read_unlock();
856 			spin_unlock(&clp->cl_lock);
857 		}
858 		nfs_sb_deactive(server->super);
859 		spin_lock(&clp->cl_lock);
860 		rcu_read_lock();
861 		return -EAGAIN;
862 	}
863 	return 0;
864 }
865 
866 static int
pnfs_layout_free_bulk_destroy_list(struct list_head * layout_list,bool is_bulk_recall)867 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
868 		bool is_bulk_recall)
869 {
870 	struct pnfs_layout_hdr *lo;
871 	struct inode *inode;
872 	LIST_HEAD(lseg_list);
873 	int ret = 0;
874 
875 	while (!list_empty(layout_list)) {
876 		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
877 				plh_bulk_destroy);
878 		dprintk("%s freeing layout for inode %lu\n", __func__,
879 			lo->plh_inode->i_ino);
880 		inode = lo->plh_inode;
881 
882 		pnfs_layoutcommit_inode(inode, false);
883 
884 		spin_lock(&inode->i_lock);
885 		list_del_init(&lo->plh_bulk_destroy);
886 		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
887 			if (is_bulk_recall)
888 				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
889 			ret = -EAGAIN;
890 		}
891 		spin_unlock(&inode->i_lock);
892 		pnfs_free_lseg_list(&lseg_list);
893 		/* Free all lsegs that are attached to commit buckets */
894 		nfs_commit_inode(inode, 0);
895 		pnfs_put_layout_hdr(lo);
896 		nfs_iput_and_deactive(inode);
897 	}
898 	return ret;
899 }
900 
901 int
pnfs_destroy_layouts_byfsid(struct nfs_client * clp,struct nfs_fsid * fsid,bool is_recall)902 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
903 		struct nfs_fsid *fsid,
904 		bool is_recall)
905 {
906 	struct nfs_server *server;
907 	LIST_HEAD(layout_list);
908 
909 	spin_lock(&clp->cl_lock);
910 	rcu_read_lock();
911 restart:
912 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
913 		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
914 			continue;
915 		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
916 				server,
917 				&layout_list) != 0)
918 			goto restart;
919 	}
920 	rcu_read_unlock();
921 	spin_unlock(&clp->cl_lock);
922 
923 	if (list_empty(&layout_list))
924 		return 0;
925 	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
926 }
927 
928 int
pnfs_destroy_layouts_byclid(struct nfs_client * clp,bool is_recall)929 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
930 		bool is_recall)
931 {
932 	struct nfs_server *server;
933 	LIST_HEAD(layout_list);
934 
935 	spin_lock(&clp->cl_lock);
936 	rcu_read_lock();
937 restart:
938 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
939 		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
940 					server,
941 					&layout_list) != 0)
942 			goto restart;
943 	}
944 	rcu_read_unlock();
945 	spin_unlock(&clp->cl_lock);
946 
947 	if (list_empty(&layout_list))
948 		return 0;
949 	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
950 }
951 
952 /*
953  * Called by the state manager to remove all layouts established under an
954  * expired lease.
955  */
956 void
pnfs_destroy_all_layouts(struct nfs_client * clp)957 pnfs_destroy_all_layouts(struct nfs_client *clp)
958 {
959 	nfs4_deviceid_mark_client_invalid(clp);
960 	nfs4_deviceid_purge_client(clp);
961 
962 	pnfs_destroy_layouts_byclid(clp, false);
963 }
964 
965 static void
pnfs_set_layout_cred(struct pnfs_layout_hdr * lo,const struct cred * cred)966 pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
967 {
968 	const struct cred *old;
969 
970 	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
971 		old = xchg(&lo->plh_lc_cred, get_cred(cred));
972 		put_cred(old);
973 	}
974 }
975 
976 /* update lo->plh_stateid with new if is more recent */
977 void
pnfs_set_layout_stateid(struct pnfs_layout_hdr * lo,const nfs4_stateid * new,const struct cred * cred,bool update_barrier)978 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
979 			const struct cred *cred, bool update_barrier)
980 {
981 	u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
982 	u32 newseq = be32_to_cpu(new->seqid);
983 
984 	if (!pnfs_layout_is_valid(lo)) {
985 		pnfs_set_layout_cred(lo, cred);
986 		nfs4_stateid_copy(&lo->plh_stateid, new);
987 		lo->plh_barrier = newseq;
988 		pnfs_clear_layoutreturn_info(lo);
989 		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
990 		return;
991 	}
992 
993 	if (pnfs_seqid_is_newer(newseq, oldseq))
994 		nfs4_stateid_copy(&lo->plh_stateid, new);
995 
996 	if (update_barrier) {
997 		pnfs_barrier_update(lo, newseq);
998 		return;
999 	}
1000 	/*
1001 	 * Because of wraparound, we want to keep the barrier
1002 	 * "close" to the current seqids. We really only want to
1003 	 * get here from a layoutget call.
1004 	 */
1005 	if (atomic_read(&lo->plh_outstanding) == 1)
1006 		 pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
1007 }
1008 
1009 static bool
pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr * lo,const nfs4_stateid * stateid)1010 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
1011 		const nfs4_stateid *stateid)
1012 {
1013 	u32 seqid = be32_to_cpu(stateid->seqid);
1014 
1015 	return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
1016 }
1017 
1018 /* lget is set to 1 if called from inside send_layoutget call chain */
1019 static bool
pnfs_layoutgets_blocked(const struct pnfs_layout_hdr * lo)1020 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
1021 {
1022 	return lo->plh_block_lgets ||
1023 		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
1024 }
1025 
1026 static struct nfs_server *
pnfs_find_server(struct inode * inode,struct nfs_open_context * ctx)1027 pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
1028 {
1029 	struct nfs_server *server;
1030 
1031 	if (inode) {
1032 		server = NFS_SERVER(inode);
1033 	} else {
1034 		struct dentry *parent_dir = dget_parent(ctx->dentry);
1035 		server = NFS_SERVER(parent_dir->d_inode);
1036 		dput(parent_dir);
1037 	}
1038 	return server;
1039 }
1040 
nfs4_free_pages(struct page ** pages,size_t size)1041 static void nfs4_free_pages(struct page **pages, size_t size)
1042 {
1043 	int i;
1044 
1045 	if (!pages)
1046 		return;
1047 
1048 	for (i = 0; i < size; i++) {
1049 		if (!pages[i])
1050 			break;
1051 		__free_page(pages[i]);
1052 	}
1053 	kfree(pages);
1054 }
1055 
nfs4_alloc_pages(size_t size,gfp_t gfp_flags)1056 static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1057 {
1058 	struct page **pages;
1059 	int i;
1060 
1061 	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1062 	if (!pages) {
1063 		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1064 		return NULL;
1065 	}
1066 
1067 	for (i = 0; i < size; i++) {
1068 		pages[i] = alloc_page(gfp_flags);
1069 		if (!pages[i]) {
1070 			dprintk("%s: failed to allocate page\n", __func__);
1071 			nfs4_free_pages(pages, i);
1072 			return NULL;
1073 		}
1074 	}
1075 
1076 	return pages;
1077 }
1078 
1079 static struct nfs4_layoutget *
pnfs_alloc_init_layoutget_args(struct inode * ino,struct nfs_open_context * ctx,const nfs4_stateid * stateid,const struct pnfs_layout_range * range,gfp_t gfp_flags)1080 pnfs_alloc_init_layoutget_args(struct inode *ino,
1081 	   struct nfs_open_context *ctx,
1082 	   const nfs4_stateid *stateid,
1083 	   const struct pnfs_layout_range *range,
1084 	   gfp_t gfp_flags)
1085 {
1086 	struct nfs_server *server = pnfs_find_server(ino, ctx);
1087 	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1088 	size_t max_pages = max_response_pages(server);
1089 	struct nfs4_layoutget *lgp;
1090 
1091 	dprintk("--> %s\n", __func__);
1092 
1093 	lgp = kzalloc(sizeof(*lgp), gfp_flags);
1094 	if (lgp == NULL)
1095 		return NULL;
1096 
1097 	if (max_reply_sz) {
1098 		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1099 		if (npages < max_pages)
1100 			max_pages = npages;
1101 	}
1102 
1103 	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1104 	if (!lgp->args.layout.pages) {
1105 		kfree(lgp);
1106 		return NULL;
1107 	}
1108 	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1109 	lgp->res.layoutp = &lgp->args.layout;
1110 
1111 	/* Don't confuse uninitialised result and success */
1112 	lgp->res.status = -NFS4ERR_DELAY;
1113 
1114 	lgp->args.minlength = PAGE_SIZE;
1115 	if (lgp->args.minlength > range->length)
1116 		lgp->args.minlength = range->length;
1117 	if (ino) {
1118 		loff_t i_size = i_size_read(ino);
1119 
1120 		if (range->iomode == IOMODE_READ) {
1121 			if (range->offset >= i_size)
1122 				lgp->args.minlength = 0;
1123 			else if (i_size - range->offset < lgp->args.minlength)
1124 				lgp->args.minlength = i_size - range->offset;
1125 		}
1126 	}
1127 	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1128 	pnfs_copy_range(&lgp->args.range, range);
1129 	lgp->args.type = server->pnfs_curr_ld->id;
1130 	lgp->args.inode = ino;
1131 	lgp->args.ctx = get_nfs_open_context(ctx);
1132 	nfs4_stateid_copy(&lgp->args.stateid, stateid);
1133 	lgp->gfp_flags = gfp_flags;
1134 	lgp->cred = ctx->cred;
1135 	return lgp;
1136 }
1137 
pnfs_layoutget_free(struct nfs4_layoutget * lgp)1138 void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1139 {
1140 	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1141 
1142 	nfs4_free_pages(lgp->args.layout.pages, max_pages);
1143 	pnfs_put_layout_hdr(lgp->lo);
1144 	put_nfs_open_context(lgp->args.ctx);
1145 	kfree(lgp);
1146 }
1147 
pnfs_clear_layoutcommit(struct inode * inode,struct list_head * head)1148 static void pnfs_clear_layoutcommit(struct inode *inode,
1149 		struct list_head *head)
1150 {
1151 	struct nfs_inode *nfsi = NFS_I(inode);
1152 	struct pnfs_layout_segment *lseg, *tmp;
1153 
1154 	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1155 		return;
1156 	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1157 		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1158 			continue;
1159 		pnfs_lseg_dec_and_remove_zero(lseg, head);
1160 	}
1161 }
1162 
pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr * lo,const nfs4_stateid * arg_stateid,const struct pnfs_layout_range * range,const nfs4_stateid * stateid)1163 void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1164 		const nfs4_stateid *arg_stateid,
1165 		const struct pnfs_layout_range *range,
1166 		const nfs4_stateid *stateid)
1167 {
1168 	struct inode *inode = lo->plh_inode;
1169 	LIST_HEAD(freeme);
1170 
1171 	spin_lock(&inode->i_lock);
1172 	if (!pnfs_layout_is_valid(lo) ||
1173 	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1174 		goto out_unlock;
1175 	if (stateid) {
1176 		u32 seq = be32_to_cpu(arg_stateid->seqid);
1177 
1178 		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1179 		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1180 		pnfs_set_layout_stateid(lo, stateid, NULL, true);
1181 	} else
1182 		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1183 out_unlock:
1184 	pnfs_clear_layoutreturn_waitbit(lo);
1185 	spin_unlock(&inode->i_lock);
1186 	pnfs_free_lseg_list(&freeme);
1187 
1188 }
1189 
1190 static bool
pnfs_prepare_layoutreturn(struct pnfs_layout_hdr * lo,nfs4_stateid * stateid,const struct cred ** cred,enum pnfs_iomode * iomode)1191 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1192 		nfs4_stateid *stateid,
1193 		const struct cred **cred,
1194 		enum pnfs_iomode *iomode)
1195 {
1196 	/* Serialise LAYOUTGET/LAYOUTRETURN */
1197 	if (atomic_read(&lo->plh_outstanding) != 0)
1198 		return false;
1199 	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1200 		return false;
1201 	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1202 	pnfs_get_layout_hdr(lo);
1203 	nfs4_stateid_copy(stateid, &lo->plh_stateid);
1204 	*cred = get_cred(lo->plh_lc_cred);
1205 	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1206 		if (lo->plh_return_seq != 0)
1207 			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1208 		if (iomode != NULL)
1209 			*iomode = lo->plh_return_iomode;
1210 		pnfs_clear_layoutreturn_info(lo);
1211 	} else if (iomode != NULL)
1212 		*iomode = IOMODE_ANY;
1213 	pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
1214 	return true;
1215 }
1216 
1217 static void
pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args * args,struct pnfs_layout_hdr * lo,const nfs4_stateid * stateid,enum pnfs_iomode iomode)1218 pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1219 		struct pnfs_layout_hdr *lo,
1220 		const nfs4_stateid *stateid,
1221 		enum pnfs_iomode iomode)
1222 {
1223 	struct inode *inode = lo->plh_inode;
1224 
1225 	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1226 	args->inode = inode;
1227 	args->range.iomode = iomode;
1228 	args->range.offset = 0;
1229 	args->range.length = NFS4_MAX_UINT64;
1230 	args->layout = lo;
1231 	nfs4_stateid_copy(&args->stateid, stateid);
1232 }
1233 
1234 static int
pnfs_send_layoutreturn(struct pnfs_layout_hdr * lo,const nfs4_stateid * stateid,const struct cred ** pcred,enum pnfs_iomode iomode,bool sync)1235 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1236 		       const nfs4_stateid *stateid,
1237 		       const struct cred **pcred,
1238 		       enum pnfs_iomode iomode,
1239 		       bool sync)
1240 {
1241 	struct inode *ino = lo->plh_inode;
1242 	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1243 	struct nfs4_layoutreturn *lrp;
1244 	const struct cred *cred = *pcred;
1245 	int status = 0;
1246 
1247 	*pcred = NULL;
1248 	lrp = kzalloc(sizeof(*lrp), nfs_io_gfp_mask());
1249 	if (unlikely(lrp == NULL)) {
1250 		status = -ENOMEM;
1251 		spin_lock(&ino->i_lock);
1252 		pnfs_clear_layoutreturn_waitbit(lo);
1253 		spin_unlock(&ino->i_lock);
1254 		put_cred(cred);
1255 		pnfs_put_layout_hdr(lo);
1256 		goto out;
1257 	}
1258 
1259 	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1260 	lrp->args.ld_private = &lrp->ld_private;
1261 	lrp->clp = NFS_SERVER(ino)->nfs_client;
1262 	lrp->cred = cred;
1263 	if (ld->prepare_layoutreturn)
1264 		ld->prepare_layoutreturn(&lrp->args);
1265 
1266 	status = nfs4_proc_layoutreturn(lrp, sync);
1267 out:
1268 	dprintk("<-- %s status: %d\n", __func__, status);
1269 	return status;
1270 }
1271 
1272 static bool
pnfs_layout_segments_returnable(struct pnfs_layout_hdr * lo,enum pnfs_iomode iomode,u32 seq)1273 pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
1274 				enum pnfs_iomode iomode,
1275 				u32 seq)
1276 {
1277 	struct pnfs_layout_range recall_range = {
1278 		.length = NFS4_MAX_UINT64,
1279 		.iomode = iomode,
1280 	};
1281 	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
1282 					       &recall_range, seq) != -EBUSY;
1283 }
1284 
1285 /* Return true if layoutreturn is needed */
1286 static bool
pnfs_layout_need_return(struct pnfs_layout_hdr * lo)1287 pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1288 {
1289 	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1290 		return false;
1291 	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
1292 					       lo->plh_return_seq);
1293 }
1294 
pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr * lo)1295 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1296 {
1297 	struct inode *inode= lo->plh_inode;
1298 
1299 	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1300 		return;
1301 	spin_lock(&inode->i_lock);
1302 	if (pnfs_layout_need_return(lo)) {
1303 		const struct cred *cred;
1304 		nfs4_stateid stateid;
1305 		enum pnfs_iomode iomode;
1306 		bool send;
1307 
1308 		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1309 		spin_unlock(&inode->i_lock);
1310 		if (send) {
1311 			/* Send an async layoutreturn so we dont deadlock */
1312 			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
1313 		}
1314 	} else
1315 		spin_unlock(&inode->i_lock);
1316 }
1317 
1318 /*
1319  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1320  * when the layout segment list is empty.
1321  *
1322  * Note that a pnfs_layout_hdr can exist with an empty layout segment
1323  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1324  * deviceid is marked invalid.
1325  */
1326 int
_pnfs_return_layout(struct inode * ino)1327 _pnfs_return_layout(struct inode *ino)
1328 {
1329 	struct pnfs_layout_hdr *lo = NULL;
1330 	struct nfs_inode *nfsi = NFS_I(ino);
1331 	struct pnfs_layout_range range = {
1332 		.iomode		= IOMODE_ANY,
1333 		.offset		= 0,
1334 		.length		= NFS4_MAX_UINT64,
1335 	};
1336 	LIST_HEAD(tmp_list);
1337 	const struct cred *cred;
1338 	nfs4_stateid stateid;
1339 	int status = 0;
1340 	bool send, valid_layout;
1341 
1342 	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1343 
1344 	spin_lock(&ino->i_lock);
1345 	lo = nfsi->layout;
1346 	if (!lo) {
1347 		spin_unlock(&ino->i_lock);
1348 		dprintk("NFS: %s no layout to return\n", __func__);
1349 		goto out;
1350 	}
1351 	/* Reference matched in nfs4_layoutreturn_release */
1352 	pnfs_get_layout_hdr(lo);
1353 	/* Is there an outstanding layoutreturn ? */
1354 	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1355 		spin_unlock(&ino->i_lock);
1356 		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1357 					TASK_UNINTERRUPTIBLE))
1358 			goto out_put_layout_hdr;
1359 		spin_lock(&ino->i_lock);
1360 	}
1361 	valid_layout = pnfs_layout_is_valid(lo);
1362 	pnfs_clear_layoutcommit(ino, &tmp_list);
1363 	pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
1364 
1365 	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
1366 		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1367 
1368 	/* Don't send a LAYOUTRETURN if list was initially empty */
1369 	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1370 			!valid_layout) {
1371 		spin_unlock(&ino->i_lock);
1372 		dprintk("NFS: %s no layout segments to return\n", __func__);
1373 		goto out_wait_layoutreturn;
1374 	}
1375 
1376 	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1377 	spin_unlock(&ino->i_lock);
1378 	if (send)
1379 		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
1380 out_wait_layoutreturn:
1381 	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1382 out_put_layout_hdr:
1383 	pnfs_free_lseg_list(&tmp_list);
1384 	pnfs_put_layout_hdr(lo);
1385 out:
1386 	dprintk("<-- %s status: %d\n", __func__, status);
1387 	return status;
1388 }
1389 
1390 int
pnfs_commit_and_return_layout(struct inode * inode)1391 pnfs_commit_and_return_layout(struct inode *inode)
1392 {
1393 	struct pnfs_layout_hdr *lo;
1394 	int ret;
1395 
1396 	spin_lock(&inode->i_lock);
1397 	lo = NFS_I(inode)->layout;
1398 	if (lo == NULL) {
1399 		spin_unlock(&inode->i_lock);
1400 		return 0;
1401 	}
1402 	pnfs_get_layout_hdr(lo);
1403 	/* Block new layoutgets and read/write to ds */
1404 	lo->plh_block_lgets++;
1405 	spin_unlock(&inode->i_lock);
1406 	filemap_fdatawait(inode->i_mapping);
1407 	ret = pnfs_layoutcommit_inode(inode, true);
1408 	if (ret == 0)
1409 		ret = _pnfs_return_layout(inode);
1410 	spin_lock(&inode->i_lock);
1411 	lo->plh_block_lgets--;
1412 	spin_unlock(&inode->i_lock);
1413 	pnfs_put_layout_hdr(lo);
1414 	return ret;
1415 }
1416 
pnfs_roc(struct inode * ino,struct nfs4_layoutreturn_args * args,struct nfs4_layoutreturn_res * res,const struct cred * cred)1417 bool pnfs_roc(struct inode *ino,
1418 		struct nfs4_layoutreturn_args *args,
1419 		struct nfs4_layoutreturn_res *res,
1420 		const struct cred *cred)
1421 {
1422 	struct nfs_inode *nfsi = NFS_I(ino);
1423 	struct nfs_open_context *ctx;
1424 	struct nfs4_state *state;
1425 	struct pnfs_layout_hdr *lo;
1426 	struct pnfs_layout_segment *lseg, *next;
1427 	const struct cred *lc_cred;
1428 	nfs4_stateid stateid;
1429 	enum pnfs_iomode iomode = 0;
1430 	bool layoutreturn = false, roc = false;
1431 	bool skip_read = false;
1432 
1433 	if (!nfs_have_layout(ino))
1434 		return false;
1435 retry:
1436 	rcu_read_lock();
1437 	spin_lock(&ino->i_lock);
1438 	lo = nfsi->layout;
1439 	if (!lo || !pnfs_layout_is_valid(lo) ||
1440 	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1441 		lo = NULL;
1442 		goto out_noroc;
1443 	}
1444 	pnfs_get_layout_hdr(lo);
1445 	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1446 		spin_unlock(&ino->i_lock);
1447 		rcu_read_unlock();
1448 		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1449 				TASK_UNINTERRUPTIBLE);
1450 		pnfs_put_layout_hdr(lo);
1451 		goto retry;
1452 	}
1453 
1454 	/* no roc if we hold a delegation */
1455 	if (nfs4_check_delegation(ino, FMODE_READ)) {
1456 		if (nfs4_check_delegation(ino, FMODE_WRITE))
1457 			goto out_noroc;
1458 		skip_read = true;
1459 	}
1460 
1461 	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1462 		state = ctx->state;
1463 		if (state == NULL)
1464 			continue;
1465 		/* Don't return layout if there is open file state */
1466 		if (state->state & FMODE_WRITE)
1467 			goto out_noroc;
1468 		if (state->state & FMODE_READ)
1469 			skip_read = true;
1470 	}
1471 
1472 
1473 	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1474 		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1475 			continue;
1476 		/* If we are sending layoutreturn, invalidate all valid lsegs */
1477 		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1478 			continue;
1479 		/*
1480 		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1481 		 * doesn't invalidate the layout for us.
1482 		 */
1483 		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1484 		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1485 			continue;
1486 		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1487 	}
1488 
1489 	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1490 		goto out_noroc;
1491 
1492 	/* ROC in two conditions:
1493 	 * 1. there are ROC lsegs
1494 	 * 2. we don't send layoutreturn
1495 	 */
1496 	/* lo ref dropped in pnfs_roc_release() */
1497 	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1498 	/* If the creds don't match, we can't compound the layoutreturn */
1499 	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1500 		goto out_noroc;
1501 
1502 	roc = layoutreturn;
1503 	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1504 	res->lrs_present = 0;
1505 	layoutreturn = false;
1506 	put_cred(lc_cred);
1507 
1508 out_noroc:
1509 	spin_unlock(&ino->i_lock);
1510 	rcu_read_unlock();
1511 	pnfs_layoutcommit_inode(ino, true);
1512 	if (roc) {
1513 		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1514 		if (ld->prepare_layoutreturn)
1515 			ld->prepare_layoutreturn(args);
1516 		pnfs_put_layout_hdr(lo);
1517 		return true;
1518 	}
1519 	if (layoutreturn)
1520 		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
1521 	pnfs_put_layout_hdr(lo);
1522 	return false;
1523 }
1524 
pnfs_roc_done(struct rpc_task * task,struct nfs4_layoutreturn_args ** argpp,struct nfs4_layoutreturn_res ** respp,int * ret)1525 int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
1526 		  struct nfs4_layoutreturn_res **respp, int *ret)
1527 {
1528 	struct nfs4_layoutreturn_args *arg = *argpp;
1529 	int retval = -EAGAIN;
1530 
1531 	if (!arg)
1532 		return 0;
1533 	/* Handle Layoutreturn errors */
1534 	switch (*ret) {
1535 	case 0:
1536 		retval = 0;
1537 		break;
1538 	case -NFS4ERR_NOMATCHING_LAYOUT:
1539 		/* Was there an RPC level error? If not, retry */
1540 		if (task->tk_rpc_status == 0)
1541 			break;
1542 		/* If the call was not sent, let caller handle it */
1543 		if (!RPC_WAS_SENT(task))
1544 			return 0;
1545 		/*
1546 		 * Otherwise, assume the call succeeded and
1547 		 * that we need to release the layout
1548 		 */
1549 		*ret = 0;
1550 		(*respp)->lrs_present = 0;
1551 		retval = 0;
1552 		break;
1553 	case -NFS4ERR_DELAY:
1554 		/* Let the caller handle the retry */
1555 		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1556 		return 0;
1557 	case -NFS4ERR_OLD_STATEID:
1558 		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1559 						     &arg->range, arg->inode))
1560 			break;
1561 		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1562 		return -EAGAIN;
1563 	}
1564 	*argpp = NULL;
1565 	*respp = NULL;
1566 	return retval;
1567 }
1568 
pnfs_roc_release(struct nfs4_layoutreturn_args * args,struct nfs4_layoutreturn_res * res,int ret)1569 void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1570 		struct nfs4_layoutreturn_res *res,
1571 		int ret)
1572 {
1573 	struct pnfs_layout_hdr *lo = args->layout;
1574 	struct inode *inode = args->inode;
1575 	const nfs4_stateid *res_stateid = NULL;
1576 	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1577 
1578 	switch (ret) {
1579 	case -NFS4ERR_NOMATCHING_LAYOUT:
1580 		spin_lock(&inode->i_lock);
1581 		if (pnfs_layout_is_valid(lo) &&
1582 		    nfs4_stateid_match_other(&args->stateid, &lo->plh_stateid))
1583 			pnfs_set_plh_return_info(lo, args->range.iomode, 0);
1584 		pnfs_clear_layoutreturn_waitbit(lo);
1585 		spin_unlock(&inode->i_lock);
1586 		break;
1587 	case 0:
1588 		if (res->lrs_present)
1589 			res_stateid = &res->stateid;
1590 		fallthrough;
1591 	default:
1592 		pnfs_layoutreturn_free_lsegs(lo, &args->stateid, &args->range,
1593 					     res_stateid);
1594 	}
1595 	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
1596 	if (ld_private && ld_private->ops && ld_private->ops->free)
1597 		ld_private->ops->free(ld_private);
1598 	pnfs_put_layout_hdr(lo);
1599 }
1600 
pnfs_wait_on_layoutreturn(struct inode * ino,struct rpc_task * task)1601 bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1602 {
1603 	struct nfs_inode *nfsi = NFS_I(ino);
1604         struct pnfs_layout_hdr *lo;
1605         bool sleep = false;
1606 
1607 	/* we might not have grabbed lo reference. so need to check under
1608 	 * i_lock */
1609         spin_lock(&ino->i_lock);
1610         lo = nfsi->layout;
1611         if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1612                 rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1613                 sleep = true;
1614 	}
1615         spin_unlock(&ino->i_lock);
1616         return sleep;
1617 }
1618 
1619 /*
1620  * Compare two layout segments for sorting into layout cache.
1621  * We want to preferentially return RW over RO layouts, so ensure those
1622  * are seen first.
1623  */
1624 static s64
pnfs_lseg_range_cmp(const struct pnfs_layout_range * l1,const struct pnfs_layout_range * l2)1625 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1626 	   const struct pnfs_layout_range *l2)
1627 {
1628 	s64 d;
1629 
1630 	/* high offset > low offset */
1631 	d = l1->offset - l2->offset;
1632 	if (d)
1633 		return d;
1634 
1635 	/* short length > long length */
1636 	d = l2->length - l1->length;
1637 	if (d)
1638 		return d;
1639 
1640 	/* read > read/write */
1641 	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1642 }
1643 
1644 static bool
pnfs_lseg_range_is_after(const struct pnfs_layout_range * l1,const struct pnfs_layout_range * l2)1645 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1646 		const struct pnfs_layout_range *l2)
1647 {
1648 	return pnfs_lseg_range_cmp(l1, l2) > 0;
1649 }
1650 
1651 static bool
pnfs_lseg_no_merge(struct pnfs_layout_segment * lseg,struct pnfs_layout_segment * old)1652 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1653 		struct pnfs_layout_segment *old)
1654 {
1655 	return false;
1656 }
1657 
1658 void
pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr * lo,struct pnfs_layout_segment * lseg,bool (* is_after)(const struct pnfs_layout_range *,const struct pnfs_layout_range *),bool (* do_merge)(struct pnfs_layout_segment *,struct pnfs_layout_segment *),struct list_head * free_me)1659 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1660 		   struct pnfs_layout_segment *lseg,
1661 		   bool (*is_after)(const struct pnfs_layout_range *,
1662 			   const struct pnfs_layout_range *),
1663 		   bool (*do_merge)(struct pnfs_layout_segment *,
1664 			   struct pnfs_layout_segment *),
1665 		   struct list_head *free_me)
1666 {
1667 	struct pnfs_layout_segment *lp, *tmp;
1668 
1669 	dprintk("%s:Begin\n", __func__);
1670 
1671 	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1672 		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1673 			continue;
1674 		if (do_merge(lseg, lp)) {
1675 			mark_lseg_invalid(lp, free_me);
1676 			continue;
1677 		}
1678 		if (is_after(&lseg->pls_range, &lp->pls_range))
1679 			continue;
1680 		list_add_tail(&lseg->pls_list, &lp->pls_list);
1681 		dprintk("%s: inserted lseg %p "
1682 			"iomode %d offset %llu length %llu before "
1683 			"lp %p iomode %d offset %llu length %llu\n",
1684 			__func__, lseg, lseg->pls_range.iomode,
1685 			lseg->pls_range.offset, lseg->pls_range.length,
1686 			lp, lp->pls_range.iomode, lp->pls_range.offset,
1687 			lp->pls_range.length);
1688 		goto out;
1689 	}
1690 	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1691 	dprintk("%s: inserted lseg %p "
1692 		"iomode %d offset %llu length %llu at tail\n",
1693 		__func__, lseg, lseg->pls_range.iomode,
1694 		lseg->pls_range.offset, lseg->pls_range.length);
1695 out:
1696 	pnfs_get_layout_hdr(lo);
1697 
1698 	dprintk("%s:Return\n", __func__);
1699 }
1700 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1701 
1702 static void
pnfs_layout_insert_lseg(struct pnfs_layout_hdr * lo,struct pnfs_layout_segment * lseg,struct list_head * free_me)1703 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1704 		   struct pnfs_layout_segment *lseg,
1705 		   struct list_head *free_me)
1706 {
1707 	struct inode *inode = lo->plh_inode;
1708 	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1709 
1710 	if (ld->add_lseg != NULL)
1711 		ld->add_lseg(lo, lseg, free_me);
1712 	else
1713 		pnfs_generic_layout_insert_lseg(lo, lseg,
1714 				pnfs_lseg_range_is_after,
1715 				pnfs_lseg_no_merge,
1716 				free_me);
1717 }
1718 
1719 static struct pnfs_layout_hdr *
alloc_init_layout_hdr(struct inode * ino,struct nfs_open_context * ctx,gfp_t gfp_flags)1720 alloc_init_layout_hdr(struct inode *ino,
1721 		      struct nfs_open_context *ctx,
1722 		      gfp_t gfp_flags)
1723 {
1724 	struct pnfs_layout_hdr *lo;
1725 
1726 	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1727 	if (!lo)
1728 		return NULL;
1729 	refcount_set(&lo->plh_refcount, 1);
1730 	INIT_LIST_HEAD(&lo->plh_layouts);
1731 	INIT_LIST_HEAD(&lo->plh_segs);
1732 	INIT_LIST_HEAD(&lo->plh_return_segs);
1733 	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1734 	lo->plh_inode = ino;
1735 	lo->plh_lc_cred = get_cred(ctx->cred);
1736 	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1737 	return lo;
1738 }
1739 
1740 static struct pnfs_layout_hdr *
pnfs_find_alloc_layout(struct inode * ino,struct nfs_open_context * ctx,gfp_t gfp_flags)1741 pnfs_find_alloc_layout(struct inode *ino,
1742 		       struct nfs_open_context *ctx,
1743 		       gfp_t gfp_flags)
1744 	__releases(&ino->i_lock)
1745 	__acquires(&ino->i_lock)
1746 {
1747 	struct nfs_inode *nfsi = NFS_I(ino);
1748 	struct pnfs_layout_hdr *new = NULL;
1749 
1750 	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1751 
1752 	if (nfsi->layout != NULL)
1753 		goto out_existing;
1754 	spin_unlock(&ino->i_lock);
1755 	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1756 	spin_lock(&ino->i_lock);
1757 
1758 	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1759 		nfsi->layout = new;
1760 		return new;
1761 	} else if (new != NULL)
1762 		pnfs_free_layout_hdr(new);
1763 out_existing:
1764 	pnfs_get_layout_hdr(nfsi->layout);
1765 	return nfsi->layout;
1766 }
1767 
1768 /*
1769  * iomode matching rules:
1770  * iomode	lseg	strict match
1771  *                      iomode
1772  * -----	-----	------ -----
1773  * ANY		READ	N/A    true
1774  * ANY		RW	N/A    true
1775  * RW		READ	N/A    false
1776  * RW		RW	N/A    true
1777  * READ		READ	N/A    true
1778  * READ		RW	true   false
1779  * READ		RW	false  true
1780  */
1781 static bool
pnfs_lseg_range_match(const struct pnfs_layout_range * ls_range,const struct pnfs_layout_range * range,bool strict_iomode)1782 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1783 		 const struct pnfs_layout_range *range,
1784 		 bool strict_iomode)
1785 {
1786 	struct pnfs_layout_range range1;
1787 
1788 	if ((range->iomode == IOMODE_RW &&
1789 	     ls_range->iomode != IOMODE_RW) ||
1790 	    (range->iomode != ls_range->iomode &&
1791 	     strict_iomode) ||
1792 	    !pnfs_lseg_range_intersecting(ls_range, range))
1793 		return false;
1794 
1795 	/* range1 covers only the first byte in the range */
1796 	range1 = *range;
1797 	range1.length = 1;
1798 	return pnfs_lseg_range_contained(ls_range, &range1);
1799 }
1800 
1801 /*
1802  * lookup range in layout
1803  */
1804 static struct pnfs_layout_segment *
pnfs_find_lseg(struct pnfs_layout_hdr * lo,struct pnfs_layout_range * range,bool strict_iomode)1805 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1806 		struct pnfs_layout_range *range,
1807 		bool strict_iomode)
1808 {
1809 	struct pnfs_layout_segment *lseg, *ret = NULL;
1810 
1811 	dprintk("%s:Begin\n", __func__);
1812 
1813 	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1814 		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1815 		    pnfs_lseg_range_match(&lseg->pls_range, range,
1816 					  strict_iomode)) {
1817 			ret = pnfs_get_lseg(lseg);
1818 			break;
1819 		}
1820 	}
1821 
1822 	dprintk("%s:Return lseg %p ref %d\n",
1823 		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1824 	return ret;
1825 }
1826 
1827 /*
1828  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1829  * to the MDS or over pNFS
1830  *
1831  * The nfs_inode read_io and write_io fields are cumulative counters reset
1832  * when there are no layout segments. Note that in pnfs_update_layout iomode
1833  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1834  * WRITE request.
1835  *
1836  * A return of true means use MDS I/O.
1837  *
1838  * From rfc 5661:
1839  * If a file's size is smaller than the file size threshold, data accesses
1840  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1841  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1842  * server.  If both file size and I/O size are provided, the client SHOULD
1843  * reach or exceed  both thresholds before sending its read or write
1844  * requests to the data server.
1845  */
pnfs_within_mdsthreshold(struct nfs_open_context * ctx,struct inode * ino,int iomode)1846 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1847 				     struct inode *ino, int iomode)
1848 {
1849 	struct nfs4_threshold *t = ctx->mdsthreshold;
1850 	struct nfs_inode *nfsi = NFS_I(ino);
1851 	loff_t fsize = i_size_read(ino);
1852 	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1853 
1854 	if (t == NULL)
1855 		return ret;
1856 
1857 	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1858 		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1859 
1860 	switch (iomode) {
1861 	case IOMODE_READ:
1862 		if (t->bm & THRESHOLD_RD) {
1863 			dprintk("%s fsize %llu\n", __func__, fsize);
1864 			size_set = true;
1865 			if (fsize < t->rd_sz)
1866 				size = true;
1867 		}
1868 		if (t->bm & THRESHOLD_RD_IO) {
1869 			dprintk("%s nfsi->read_io %llu\n", __func__,
1870 				nfsi->read_io);
1871 			io_set = true;
1872 			if (nfsi->read_io < t->rd_io_sz)
1873 				io = true;
1874 		}
1875 		break;
1876 	case IOMODE_RW:
1877 		if (t->bm & THRESHOLD_WR) {
1878 			dprintk("%s fsize %llu\n", __func__, fsize);
1879 			size_set = true;
1880 			if (fsize < t->wr_sz)
1881 				size = true;
1882 		}
1883 		if (t->bm & THRESHOLD_WR_IO) {
1884 			dprintk("%s nfsi->write_io %llu\n", __func__,
1885 				nfsi->write_io);
1886 			io_set = true;
1887 			if (nfsi->write_io < t->wr_io_sz)
1888 				io = true;
1889 		}
1890 		break;
1891 	}
1892 	if (size_set && io_set) {
1893 		if (size && io)
1894 			ret = true;
1895 	} else if (size || io)
1896 		ret = true;
1897 
1898 	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1899 	return ret;
1900 }
1901 
pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr * lo)1902 static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1903 {
1904 	/*
1905 	 * send layoutcommit as it can hold up layoutreturn due to lseg
1906 	 * reference
1907 	 */
1908 	pnfs_layoutcommit_inode(lo->plh_inode, false);
1909 	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1910 				   nfs_wait_bit_killable,
1911 				   TASK_KILLABLE);
1912 }
1913 
nfs_layoutget_begin(struct pnfs_layout_hdr * lo)1914 static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1915 {
1916 	atomic_inc(&lo->plh_outstanding);
1917 }
1918 
nfs_layoutget_end(struct pnfs_layout_hdr * lo)1919 static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1920 {
1921 	if (atomic_dec_and_test(&lo->plh_outstanding) &&
1922 	    test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags))
1923 		wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN);
1924 }
1925 
pnfs_is_first_layoutget(struct pnfs_layout_hdr * lo)1926 static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
1927 {
1928 	return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
1929 }
1930 
pnfs_clear_first_layoutget(struct pnfs_layout_hdr * lo)1931 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1932 {
1933 	unsigned long *bitlock = &lo->plh_flags;
1934 
1935 	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1936 	smp_mb__after_atomic();
1937 	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1938 }
1939 
_add_to_server_list(struct pnfs_layout_hdr * lo,struct nfs_server * server)1940 static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1941 				struct nfs_server *server)
1942 {
1943 	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
1944 		struct nfs_client *clp = server->nfs_client;
1945 
1946 		/* The lo must be on the clp list if there is any
1947 		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1948 		 */
1949 		spin_lock(&clp->cl_lock);
1950 		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
1951 		spin_unlock(&clp->cl_lock);
1952 	}
1953 }
1954 
1955 /*
1956  * Layout segment is retreived from the server if not cached.
1957  * The appropriate layout segment is referenced and returned to the caller.
1958  */
1959 struct pnfs_layout_segment *
pnfs_update_layout(struct inode * ino,struct nfs_open_context * ctx,loff_t pos,u64 count,enum pnfs_iomode iomode,bool strict_iomode,gfp_t gfp_flags)1960 pnfs_update_layout(struct inode *ino,
1961 		   struct nfs_open_context *ctx,
1962 		   loff_t pos,
1963 		   u64 count,
1964 		   enum pnfs_iomode iomode,
1965 		   bool strict_iomode,
1966 		   gfp_t gfp_flags)
1967 {
1968 	struct pnfs_layout_range arg = {
1969 		.iomode = iomode,
1970 		.offset = pos,
1971 		.length = count,
1972 	};
1973 	unsigned pg_offset;
1974 	struct nfs_server *server = NFS_SERVER(ino);
1975 	struct nfs_client *clp = server->nfs_client;
1976 	struct pnfs_layout_hdr *lo = NULL;
1977 	struct pnfs_layout_segment *lseg = NULL;
1978 	struct nfs4_layoutget *lgp;
1979 	nfs4_stateid stateid;
1980 	long timeout = 0;
1981 	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1982 	bool first;
1983 
1984 	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1985 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1986 				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1987 		goto out;
1988 	}
1989 
1990 	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1991 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1992 				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1993 		goto out;
1994 	}
1995 
1996 lookup_again:
1997 	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
1998 	if (IS_ERR(lseg))
1999 		goto out;
2000 	first = false;
2001 	spin_lock(&ino->i_lock);
2002 	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
2003 	if (lo == NULL) {
2004 		spin_unlock(&ino->i_lock);
2005 		lseg = ERR_PTR(-ENOMEM);
2006 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2007 				 PNFS_UPDATE_LAYOUT_NOMEM);
2008 		goto out;
2009 	}
2010 
2011 	/* Do we even need to bother with this? */
2012 	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
2013 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2014 				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
2015 		dprintk("%s matches recall, use MDS\n", __func__);
2016 		goto out_unlock;
2017 	}
2018 
2019 	/* if LAYOUTGET already failed once we don't try again */
2020 	if (pnfs_layout_io_test_failed(lo, iomode)) {
2021 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2022 				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
2023 		goto out_unlock;
2024 	}
2025 
2026 	/*
2027 	 * If the layout segment list is empty, but there are outstanding
2028 	 * layoutget calls, then they might be subject to a layoutrecall.
2029 	 */
2030 	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2031 	    atomic_read(&lo->plh_outstanding) != 0) {
2032 		spin_unlock(&ino->i_lock);
2033 		lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN,
2034 					   TASK_KILLABLE));
2035 		if (IS_ERR(lseg))
2036 			goto out_put_layout_hdr;
2037 		pnfs_put_layout_hdr(lo);
2038 		goto lookup_again;
2039 	}
2040 
2041 	/*
2042 	 * Because we free lsegs when sending LAYOUTRETURN, we need to wait
2043 	 * for LAYOUTRETURN.
2044 	 */
2045 	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2046 		spin_unlock(&ino->i_lock);
2047 		dprintk("%s wait for layoutreturn\n", __func__);
2048 		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2049 		if (!IS_ERR(lseg)) {
2050 			pnfs_put_layout_hdr(lo);
2051 			dprintk("%s retrying\n", __func__);
2052 			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2053 						 lseg,
2054 						 PNFS_UPDATE_LAYOUT_RETRY);
2055 			goto lookup_again;
2056 		}
2057 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2058 					 PNFS_UPDATE_LAYOUT_RETURN);
2059 		goto out_put_layout_hdr;
2060 	}
2061 
2062 	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
2063 	if (lseg) {
2064 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2065 				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
2066 		goto out_unlock;
2067 	}
2068 
2069 	/*
2070 	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
2071 	 * stateid, or it has been invalidated, then we must use the open
2072 	 * stateid.
2073 	 */
2074 	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2075 		int status;
2076 
2077 		/*
2078 		 * The first layoutget for the file. Need to serialize per
2079 		 * RFC 5661 Errata 3208.
2080 		 */
2081 		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2082 				     &lo->plh_flags)) {
2083 			spin_unlock(&ino->i_lock);
2084 			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2085 						NFS_LAYOUT_FIRST_LAYOUTGET,
2086 						TASK_KILLABLE));
2087 			if (IS_ERR(lseg))
2088 				goto out_put_layout_hdr;
2089 			pnfs_put_layout_hdr(lo);
2090 			dprintk("%s retrying\n", __func__);
2091 			goto lookup_again;
2092 		}
2093 
2094 		spin_unlock(&ino->i_lock);
2095 		first = true;
2096 		status = nfs4_select_rw_stateid(ctx->state,
2097 					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2098 					NULL, &stateid, NULL);
2099 		if (status != 0) {
2100 			lseg = ERR_PTR(status);
2101 			trace_pnfs_update_layout(ino, pos, count,
2102 					iomode, lo, lseg,
2103 					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2104 			nfs4_schedule_stateid_recovery(server, ctx->state);
2105 			pnfs_clear_first_layoutget(lo);
2106 			pnfs_put_layout_hdr(lo);
2107 			goto lookup_again;
2108 		}
2109 		spin_lock(&ino->i_lock);
2110 	} else {
2111 		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2112 	}
2113 
2114 	if (pnfs_layoutgets_blocked(lo)) {
2115 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2116 				PNFS_UPDATE_LAYOUT_BLOCKED);
2117 		goto out_unlock;
2118 	}
2119 	nfs_layoutget_begin(lo);
2120 	spin_unlock(&ino->i_lock);
2121 
2122 	_add_to_server_list(lo, server);
2123 
2124 	pg_offset = arg.offset & ~PAGE_MASK;
2125 	if (pg_offset) {
2126 		arg.offset -= pg_offset;
2127 		arg.length += pg_offset;
2128 	}
2129 	if (arg.length != NFS4_MAX_UINT64)
2130 		arg.length = PAGE_ALIGN(arg.length);
2131 
2132 	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2133 	if (!lgp) {
2134 		lseg = ERR_PTR(-ENOMEM);
2135 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2136 					 PNFS_UPDATE_LAYOUT_NOMEM);
2137 		nfs_layoutget_end(lo);
2138 		goto out_put_layout_hdr;
2139 	}
2140 
2141 	lgp->lo = lo;
2142 	pnfs_get_layout_hdr(lo);
2143 
2144 	lseg = nfs4_proc_layoutget(lgp, &timeout);
2145 	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2146 				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2147 	nfs_layoutget_end(lo);
2148 	if (IS_ERR(lseg)) {
2149 		switch(PTR_ERR(lseg)) {
2150 		case -EBUSY:
2151 			if (time_after(jiffies, giveup))
2152 				lseg = NULL;
2153 			break;
2154 		case -ERECALLCONFLICT:
2155 		case -EAGAIN:
2156 			break;
2157 		case -ENODATA:
2158 			/* The server returned NFS4ERR_LAYOUTUNAVAILABLE */
2159 			pnfs_layout_set_fail_bit(
2160 				lo, pnfs_iomode_to_fail_bit(iomode));
2161 			lseg = NULL;
2162 			goto out_put_layout_hdr;
2163 		default:
2164 			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2165 				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2166 				lseg = NULL;
2167 			}
2168 			goto out_put_layout_hdr;
2169 		}
2170 		if (lseg) {
2171 			if (first)
2172 				pnfs_clear_first_layoutget(lo);
2173 			trace_pnfs_update_layout(ino, pos, count,
2174 				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2175 			pnfs_put_layout_hdr(lo);
2176 			goto lookup_again;
2177 		}
2178 	} else {
2179 		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2180 	}
2181 
2182 out_put_layout_hdr:
2183 	if (first)
2184 		pnfs_clear_first_layoutget(lo);
2185 	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2186 				 PNFS_UPDATE_LAYOUT_EXIT);
2187 	pnfs_put_layout_hdr(lo);
2188 out:
2189 	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2190 			"(%s, offset: %llu, length: %llu)\n",
2191 			__func__, ino->i_sb->s_id,
2192 			(unsigned long long)NFS_FILEID(ino),
2193 			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2194 			iomode==IOMODE_RW ?  "read/write" : "read-only",
2195 			(unsigned long long)pos,
2196 			(unsigned long long)count);
2197 	return lseg;
2198 out_unlock:
2199 	spin_unlock(&ino->i_lock);
2200 	goto out_put_layout_hdr;
2201 }
2202 EXPORT_SYMBOL_GPL(pnfs_update_layout);
2203 
2204 static bool
pnfs_sanity_check_layout_range(struct pnfs_layout_range * range)2205 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2206 {
2207 	switch (range->iomode) {
2208 	case IOMODE_READ:
2209 	case IOMODE_RW:
2210 		break;
2211 	default:
2212 		return false;
2213 	}
2214 	if (range->offset == NFS4_MAX_UINT64)
2215 		return false;
2216 	if (range->length == 0)
2217 		return false;
2218 	if (range->length != NFS4_MAX_UINT64 &&
2219 	    range->length > NFS4_MAX_UINT64 - range->offset)
2220 		return false;
2221 	return true;
2222 }
2223 
2224 static struct pnfs_layout_hdr *
_pnfs_grab_empty_layout(struct inode * ino,struct nfs_open_context * ctx)2225 _pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2226 {
2227 	struct pnfs_layout_hdr *lo;
2228 
2229 	spin_lock(&ino->i_lock);
2230 	lo = pnfs_find_alloc_layout(ino, ctx, nfs_io_gfp_mask());
2231 	if (!lo)
2232 		goto out_unlock;
2233 	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2234 		goto out_unlock;
2235 	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2236 		goto out_unlock;
2237 	if (pnfs_layoutgets_blocked(lo))
2238 		goto out_unlock;
2239 	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2240 		goto out_unlock;
2241 	nfs_layoutget_begin(lo);
2242 	spin_unlock(&ino->i_lock);
2243 	_add_to_server_list(lo, NFS_SERVER(ino));
2244 	return lo;
2245 
2246 out_unlock:
2247 	spin_unlock(&ino->i_lock);
2248 	pnfs_put_layout_hdr(lo);
2249 	return NULL;
2250 }
2251 
_lgopen_prepare_attached(struct nfs4_opendata * data,struct nfs_open_context * ctx)2252 static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2253 				     struct nfs_open_context *ctx)
2254 {
2255 	struct inode *ino = data->dentry->d_inode;
2256 	struct pnfs_layout_range rng = {
2257 		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2258 			  IOMODE_RW: IOMODE_READ,
2259 		.offset = 0,
2260 		.length = NFS4_MAX_UINT64,
2261 	};
2262 	struct nfs4_layoutget *lgp;
2263 	struct pnfs_layout_hdr *lo;
2264 
2265 	/* Heuristic: don't send layoutget if we have cached data */
2266 	if (rng.iomode == IOMODE_READ &&
2267 	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2268 		return;
2269 
2270 	lo = _pnfs_grab_empty_layout(ino, ctx);
2271 	if (!lo)
2272 		return;
2273 	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2274 					     nfs_io_gfp_mask());
2275 	if (!lgp) {
2276 		pnfs_clear_first_layoutget(lo);
2277 		nfs_layoutget_end(lo);
2278 		pnfs_put_layout_hdr(lo);
2279 		return;
2280 	}
2281 	lgp->lo = lo;
2282 	data->lgp = lgp;
2283 	data->o_arg.lg_args = &lgp->args;
2284 	data->o_res.lg_res = &lgp->res;
2285 }
2286 
_lgopen_prepare_floating(struct nfs4_opendata * data,struct nfs_open_context * ctx)2287 static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2288 				     struct nfs_open_context *ctx)
2289 {
2290 	struct inode *ino = data->dentry->d_inode;
2291 	struct pnfs_layout_range rng = {
2292 		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2293 			  IOMODE_RW: IOMODE_READ,
2294 		.offset = 0,
2295 		.length = NFS4_MAX_UINT64,
2296 	};
2297 	struct nfs4_layoutget *lgp;
2298 
2299 	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2300 					     nfs_io_gfp_mask());
2301 	if (!lgp)
2302 		return;
2303 	data->lgp = lgp;
2304 	data->o_arg.lg_args = &lgp->args;
2305 	data->o_res.lg_res = &lgp->res;
2306 }
2307 
pnfs_lgopen_prepare(struct nfs4_opendata * data,struct nfs_open_context * ctx)2308 void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2309 			 struct nfs_open_context *ctx)
2310 {
2311 	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2312 
2313 	if (!(pnfs_enabled_sb(server) &&
2314 	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2315 		return;
2316 	/* Could check on max_ops, but currently hardcoded high enough */
2317 	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2318 		return;
2319 	if (data->lgp)
2320 		return;
2321 	if (data->state)
2322 		_lgopen_prepare_attached(data, ctx);
2323 	else
2324 		_lgopen_prepare_floating(data, ctx);
2325 }
2326 
pnfs_parse_lgopen(struct inode * ino,struct nfs4_layoutget * lgp,struct nfs_open_context * ctx)2327 void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2328 		       struct nfs_open_context *ctx)
2329 {
2330 	struct pnfs_layout_hdr *lo;
2331 	struct pnfs_layout_segment *lseg;
2332 	struct nfs_server *srv = NFS_SERVER(ino);
2333 	u32 iomode;
2334 
2335 	if (!lgp)
2336 		return;
2337 	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2338 	if (lgp->res.status) {
2339 		switch (lgp->res.status) {
2340 		default:
2341 			break;
2342 		/*
2343 		 * Halt lgopen attempts if the server doesn't recognise
2344 		 * the "current stateid" value, the layout type, or the
2345 		 * layoutget operation as being valid.
2346 		 * Also if it complains about too many ops in the compound
2347 		 * or of the request/reply being too big.
2348 		 */
2349 		case -NFS4ERR_BAD_STATEID:
2350 		case -NFS4ERR_NOTSUPP:
2351 		case -NFS4ERR_REP_TOO_BIG:
2352 		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2353 		case -NFS4ERR_REQ_TOO_BIG:
2354 		case -NFS4ERR_TOO_MANY_OPS:
2355 		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2356 			srv->caps &= ~NFS_CAP_LGOPEN;
2357 		}
2358 		return;
2359 	}
2360 	if (!lgp->lo) {
2361 		lo = _pnfs_grab_empty_layout(ino, ctx);
2362 		if (!lo)
2363 			return;
2364 		lgp->lo = lo;
2365 	} else
2366 		lo = lgp->lo;
2367 
2368 	lseg = pnfs_layout_process(lgp);
2369 	if (!IS_ERR(lseg)) {
2370 		iomode = lgp->args.range.iomode;
2371 		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2372 		pnfs_put_lseg(lseg);
2373 	}
2374 }
2375 
nfs4_lgopen_release(struct nfs4_layoutget * lgp)2376 void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2377 {
2378 	if (lgp != NULL) {
2379 		if (lgp->lo) {
2380 			pnfs_clear_first_layoutget(lgp->lo);
2381 			nfs_layoutget_end(lgp->lo);
2382 		}
2383 		pnfs_layoutget_free(lgp);
2384 	}
2385 }
2386 
2387 struct pnfs_layout_segment *
pnfs_layout_process(struct nfs4_layoutget * lgp)2388 pnfs_layout_process(struct nfs4_layoutget *lgp)
2389 {
2390 	struct pnfs_layout_hdr *lo = lgp->lo;
2391 	struct nfs4_layoutget_res *res = &lgp->res;
2392 	struct pnfs_layout_segment *lseg;
2393 	struct inode *ino = lo->plh_inode;
2394 	LIST_HEAD(free_me);
2395 
2396 	if (!pnfs_sanity_check_layout_range(&res->range))
2397 		return ERR_PTR(-EINVAL);
2398 
2399 	/* Inject layout blob into I/O device driver */
2400 	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2401 	if (IS_ERR_OR_NULL(lseg)) {
2402 		if (!lseg)
2403 			lseg = ERR_PTR(-ENOMEM);
2404 
2405 		dprintk("%s: Could not allocate layout: error %ld\n",
2406 		       __func__, PTR_ERR(lseg));
2407 		return lseg;
2408 	}
2409 
2410 	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2411 
2412 	spin_lock(&ino->i_lock);
2413 	if (pnfs_layoutgets_blocked(lo)) {
2414 		dprintk("%s forget reply due to state\n", __func__);
2415 		goto out_forget;
2416 	}
2417 
2418 	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2419 	    !pnfs_is_first_layoutget(lo))
2420 		goto out_forget;
2421 
2422 	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2423 		/* existing state ID, make sure the sequence number matches. */
2424 		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2425 			if (!pnfs_layout_is_valid(lo))
2426 				lo->plh_barrier = 0;
2427 			dprintk("%s forget reply due to sequence\n", __func__);
2428 			goto out_forget;
2429 		}
2430 		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2431 	} else if (pnfs_layout_is_valid(lo)) {
2432 		/*
2433 		 * We got an entirely new state ID.  Mark all segments for the
2434 		 * inode invalid, and retry the layoutget
2435 		 */
2436 		struct pnfs_layout_range range = {
2437 			.iomode = IOMODE_ANY,
2438 			.length = NFS4_MAX_UINT64,
2439 		};
2440 		pnfs_mark_matching_lsegs_return(lo, &free_me, &range, 0);
2441 		goto out_forget;
2442 	} else {
2443 		/* We have a completely new layout */
2444 		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2445 	}
2446 
2447 	pnfs_get_lseg(lseg);
2448 	pnfs_layout_insert_lseg(lo, lseg, &free_me);
2449 
2450 
2451 	if (res->return_on_close)
2452 		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2453 
2454 	spin_unlock(&ino->i_lock);
2455 	pnfs_free_lseg_list(&free_me);
2456 	return lseg;
2457 
2458 out_forget:
2459 	spin_unlock(&ino->i_lock);
2460 	lseg->pls_layout = lo;
2461 	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2462 	return ERR_PTR(-EAGAIN);
2463 }
2464 
2465 /**
2466  * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2467  * @lo: pointer to layout header
2468  * @tmp_list: list header to be used with pnfs_free_lseg_list()
2469  * @return_range: describe layout segment ranges to be returned
2470  * @seq: stateid seqid to match
2471  *
2472  * This function is mainly intended for use by layoutrecall. It attempts
2473  * to free the layout segment immediately, or else to mark it for return
2474  * as soon as its reference count drops to zero.
2475  *
2476  * Returns
2477  * - 0: a layoutreturn needs to be scheduled.
2478  * - EBUSY: there are layout segment that are still in use.
2479  * - ENOENT: there are no layout segments that need to be returned.
2480  */
2481 int
pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr * lo,struct list_head * tmp_list,const struct pnfs_layout_range * return_range,u32 seq)2482 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2483 				struct list_head *tmp_list,
2484 				const struct pnfs_layout_range *return_range,
2485 				u32 seq)
2486 {
2487 	struct pnfs_layout_segment *lseg, *next;
2488 	int remaining = 0;
2489 
2490 	dprintk("%s:Begin lo %p\n", __func__, lo);
2491 
2492 	assert_spin_locked(&lo->plh_inode->i_lock);
2493 
2494 	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2495 		tmp_list = &lo->plh_return_segs;
2496 
2497 	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2498 		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2499 			dprintk("%s: marking lseg %p iomode %d "
2500 				"offset %llu length %llu\n", __func__,
2501 				lseg, lseg->pls_range.iomode,
2502 				lseg->pls_range.offset,
2503 				lseg->pls_range.length);
2504 			if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2505 				tmp_list = &lo->plh_return_segs;
2506 			if (mark_lseg_invalid(lseg, tmp_list))
2507 				continue;
2508 			remaining++;
2509 			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2510 		}
2511 
2512 	if (remaining) {
2513 		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2514 		return -EBUSY;
2515 	}
2516 
2517 	if (!list_empty(&lo->plh_return_segs)) {
2518 		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2519 		return 0;
2520 	}
2521 
2522 	return -ENOENT;
2523 }
2524 
2525 static void
pnfs_mark_layout_for_return(struct inode * inode,const struct pnfs_layout_range * range)2526 pnfs_mark_layout_for_return(struct inode *inode,
2527 			    const struct pnfs_layout_range *range)
2528 {
2529 	struct pnfs_layout_hdr *lo;
2530 	bool return_now = false;
2531 
2532 	spin_lock(&inode->i_lock);
2533 	lo = NFS_I(inode)->layout;
2534 	if (!pnfs_layout_is_valid(lo)) {
2535 		spin_unlock(&inode->i_lock);
2536 		return;
2537 	}
2538 	pnfs_set_plh_return_info(lo, range->iomode, 0);
2539 	/*
2540 	 * mark all matching lsegs so that we are sure to have no live
2541 	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2542 	 * for how it works.
2543 	 */
2544 	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2545 		const struct cred *cred;
2546 		nfs4_stateid stateid;
2547 		enum pnfs_iomode iomode;
2548 
2549 		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2550 		spin_unlock(&inode->i_lock);
2551 		if (return_now)
2552 			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
2553 	} else {
2554 		spin_unlock(&inode->i_lock);
2555 		nfs_commit_inode(inode, 0);
2556 	}
2557 }
2558 
pnfs_error_mark_layout_for_return(struct inode * inode,struct pnfs_layout_segment * lseg)2559 void pnfs_error_mark_layout_for_return(struct inode *inode,
2560 				       struct pnfs_layout_segment *lseg)
2561 {
2562 	struct pnfs_layout_range range = {
2563 		.iomode = lseg->pls_range.iomode,
2564 		.offset = 0,
2565 		.length = NFS4_MAX_UINT64,
2566 	};
2567 
2568 	pnfs_mark_layout_for_return(inode, &range);
2569 }
2570 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2571 
2572 static bool
pnfs_layout_can_be_returned(struct pnfs_layout_hdr * lo)2573 pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2574 {
2575 	return pnfs_layout_is_valid(lo) &&
2576 		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2577 		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2578 }
2579 
2580 static struct pnfs_layout_segment *
pnfs_find_first_lseg(struct pnfs_layout_hdr * lo,const struct pnfs_layout_range * range,enum pnfs_iomode iomode)2581 pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2582 		     const struct pnfs_layout_range *range,
2583 		     enum pnfs_iomode iomode)
2584 {
2585 	struct pnfs_layout_segment *lseg;
2586 
2587 	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2588 		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2589 			continue;
2590 		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2591 			continue;
2592 		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2593 			continue;
2594 		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2595 			return lseg;
2596 	}
2597 	return NULL;
2598 }
2599 
2600 /* Find open file states whose mode matches that of the range */
2601 static bool
pnfs_should_return_unused_layout(struct pnfs_layout_hdr * lo,const struct pnfs_layout_range * range)2602 pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2603 				 const struct pnfs_layout_range *range)
2604 {
2605 	struct list_head *head;
2606 	struct nfs_open_context *ctx;
2607 	fmode_t mode = 0;
2608 
2609 	if (!pnfs_layout_can_be_returned(lo) ||
2610 	    !pnfs_find_first_lseg(lo, range, range->iomode))
2611 		return false;
2612 
2613 	head = &NFS_I(lo->plh_inode)->open_files;
2614 	list_for_each_entry_rcu(ctx, head, list) {
2615 		if (ctx->state)
2616 			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2617 	}
2618 
2619 	switch (range->iomode) {
2620 	default:
2621 		break;
2622 	case IOMODE_READ:
2623 		mode &= ~FMODE_WRITE;
2624 		break;
2625 	case IOMODE_RW:
2626 		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2627 			mode &= ~FMODE_READ;
2628 	}
2629 	return mode == 0;
2630 }
2631 
2632 static int
pnfs_layout_return_unused_byserver(struct nfs_server * server,void * data)2633 pnfs_layout_return_unused_byserver(struct nfs_server *server, void *data)
2634 {
2635 	const struct pnfs_layout_range *range = data;
2636 	struct pnfs_layout_hdr *lo;
2637 	struct inode *inode;
2638 restart:
2639 	rcu_read_lock();
2640 	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2641 		if (!pnfs_layout_can_be_returned(lo) ||
2642 		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2643 			continue;
2644 		inode = lo->plh_inode;
2645 		spin_lock(&inode->i_lock);
2646 		if (!pnfs_should_return_unused_layout(lo, range)) {
2647 			spin_unlock(&inode->i_lock);
2648 			continue;
2649 		}
2650 		spin_unlock(&inode->i_lock);
2651 		inode = pnfs_grab_inode_layout_hdr(lo);
2652 		if (!inode)
2653 			continue;
2654 		rcu_read_unlock();
2655 		pnfs_mark_layout_for_return(inode, range);
2656 		iput(inode);
2657 		cond_resched();
2658 		goto restart;
2659 	}
2660 	rcu_read_unlock();
2661 	return 0;
2662 }
2663 
2664 void
pnfs_layout_return_unused_byclid(struct nfs_client * clp,enum pnfs_iomode iomode)2665 pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2666 				 enum pnfs_iomode iomode)
2667 {
2668 	struct pnfs_layout_range range = {
2669 		.iomode = iomode,
2670 		.offset = 0,
2671 		.length = NFS4_MAX_UINT64,
2672 	};
2673 
2674 	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2675 			&range);
2676 }
2677 
2678 void
pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor * pgio)2679 pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2680 {
2681 	if (pgio->pg_lseg == NULL ||
2682 	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2683 		return;
2684 	pnfs_put_lseg(pgio->pg_lseg);
2685 	pgio->pg_lseg = NULL;
2686 }
2687 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2688 
2689 /*
2690  * Check for any intersection between the request and the pgio->pg_lseg,
2691  * and if none, put this pgio->pg_lseg away.
2692  */
2693 void
pnfs_generic_pg_check_range(struct nfs_pageio_descriptor * pgio,struct nfs_page * req)2694 pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2695 {
2696 	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2697 		pnfs_put_lseg(pgio->pg_lseg);
2698 		pgio->pg_lseg = NULL;
2699 	}
2700 }
2701 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
2702 
2703 void
pnfs_generic_pg_init_read(struct nfs_pageio_descriptor * pgio,struct nfs_page * req)2704 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2705 {
2706 	u64 rd_size;
2707 
2708 	pnfs_generic_pg_check_layout(pgio);
2709 	pnfs_generic_pg_check_range(pgio, req);
2710 	if (pgio->pg_lseg == NULL) {
2711 		if (pgio->pg_dreq == NULL)
2712 			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2713 		else
2714 			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2715 
2716 		pgio->pg_lseg =
2717 			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2718 					   req_offset(req), rd_size,
2719 					   IOMODE_READ, false,
2720 					   nfs_io_gfp_mask());
2721 		if (IS_ERR(pgio->pg_lseg)) {
2722 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2723 			pgio->pg_lseg = NULL;
2724 			return;
2725 		}
2726 	}
2727 	/* If no lseg, fall back to read through mds */
2728 	if (pgio->pg_lseg == NULL)
2729 		nfs_pageio_reset_read_mds(pgio);
2730 
2731 }
2732 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2733 
2734 void
pnfs_generic_pg_init_write(struct nfs_pageio_descriptor * pgio,struct nfs_page * req,u64 wb_size)2735 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2736 			   struct nfs_page *req, u64 wb_size)
2737 {
2738 	pnfs_generic_pg_check_layout(pgio);
2739 	pnfs_generic_pg_check_range(pgio, req);
2740 	if (pgio->pg_lseg == NULL) {
2741 		pgio->pg_lseg =
2742 			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2743 					   req_offset(req), wb_size, IOMODE_RW,
2744 					   false, nfs_io_gfp_mask());
2745 		if (IS_ERR(pgio->pg_lseg)) {
2746 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2747 			pgio->pg_lseg = NULL;
2748 			return;
2749 		}
2750 	}
2751 	/* If no lseg, fall back to write through mds */
2752 	if (pgio->pg_lseg == NULL)
2753 		nfs_pageio_reset_write_mds(pgio);
2754 }
2755 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2756 
2757 void
pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor * desc)2758 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2759 {
2760 	if (desc->pg_lseg) {
2761 		pnfs_put_lseg(desc->pg_lseg);
2762 		desc->pg_lseg = NULL;
2763 	}
2764 }
2765 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2766 
2767 /*
2768  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2769  * of bytes (maximum @req->wb_bytes) that can be coalesced.
2770  */
2771 size_t
pnfs_generic_pg_test(struct nfs_pageio_descriptor * pgio,struct nfs_page * prev,struct nfs_page * req)2772 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2773 		     struct nfs_page *prev, struct nfs_page *req)
2774 {
2775 	unsigned int size;
2776 	u64 seg_end, req_start, seg_left;
2777 
2778 	size = nfs_generic_pg_test(pgio, prev, req);
2779 	if (!size)
2780 		return 0;
2781 
2782 	/*
2783 	 * 'size' contains the number of bytes left in the current page (up
2784 	 * to the original size asked for in @req->wb_bytes).
2785 	 *
2786 	 * Calculate how many bytes are left in the layout segment
2787 	 * and if there are less bytes than 'size', return that instead.
2788 	 *
2789 	 * Please also note that 'end_offset' is actually the offset of the
2790 	 * first byte that lies outside the pnfs_layout_range. FIXME?
2791 	 *
2792 	 */
2793 	if (pgio->pg_lseg) {
2794 		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2795 				     pgio->pg_lseg->pls_range.length);
2796 		req_start = req_offset(req);
2797 
2798 		/* start of request is past the last byte of this segment */
2799 		if (req_start >= seg_end)
2800 			return 0;
2801 
2802 		/* adjust 'size' iff there are fewer bytes left in the
2803 		 * segment than what nfs_generic_pg_test returned */
2804 		seg_left = seg_end - req_start;
2805 		if (seg_left < size)
2806 			size = (unsigned int)seg_left;
2807 	}
2808 
2809 	return size;
2810 }
2811 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2812 
pnfs_write_done_resend_to_mds(struct nfs_pgio_header * hdr)2813 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2814 {
2815 	struct nfs_pageio_descriptor pgio;
2816 
2817 	/* Resend all requests through the MDS */
2818 	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2819 			      hdr->completion_ops);
2820 	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2821 	return nfs_pageio_resend(&pgio, hdr);
2822 }
2823 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2824 
pnfs_ld_handle_write_error(struct nfs_pgio_header * hdr)2825 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2826 {
2827 
2828 	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2829 	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2830 	    PNFS_LAYOUTRET_ON_ERROR) {
2831 		pnfs_return_layout(hdr->inode);
2832 	}
2833 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2834 		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2835 }
2836 
2837 /*
2838  * Called by non rpc-based layout drivers
2839  */
pnfs_ld_write_done(struct nfs_pgio_header * hdr)2840 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2841 {
2842 	if (likely(!hdr->pnfs_error)) {
2843 		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2844 				hdr->mds_offset + hdr->res.count);
2845 		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2846 	}
2847 	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2848 	if (unlikely(hdr->pnfs_error))
2849 		pnfs_ld_handle_write_error(hdr);
2850 	hdr->mds_ops->rpc_release(hdr);
2851 }
2852 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2853 
2854 static void
pnfs_write_through_mds(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr)2855 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2856 		struct nfs_pgio_header *hdr)
2857 {
2858 	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2859 
2860 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2861 		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2862 		nfs_pageio_reset_write_mds(desc);
2863 		mirror->pg_recoalesce = 1;
2864 	}
2865 	hdr->completion_ops->completion(hdr);
2866 }
2867 
2868 static enum pnfs_try_status
pnfs_try_to_write_data(struct nfs_pgio_header * hdr,const struct rpc_call_ops * call_ops,struct pnfs_layout_segment * lseg,int how)2869 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2870 			const struct rpc_call_ops *call_ops,
2871 			struct pnfs_layout_segment *lseg,
2872 			int how)
2873 {
2874 	struct inode *inode = hdr->inode;
2875 	enum pnfs_try_status trypnfs;
2876 	struct nfs_server *nfss = NFS_SERVER(inode);
2877 
2878 	hdr->mds_ops = call_ops;
2879 
2880 	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2881 		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2882 	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2883 	if (trypnfs != PNFS_NOT_ATTEMPTED)
2884 		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2885 	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2886 	return trypnfs;
2887 }
2888 
2889 static void
pnfs_do_write(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr,int how)2890 pnfs_do_write(struct nfs_pageio_descriptor *desc,
2891 	      struct nfs_pgio_header *hdr, int how)
2892 {
2893 	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2894 	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2895 	enum pnfs_try_status trypnfs;
2896 
2897 	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2898 	switch (trypnfs) {
2899 	case PNFS_NOT_ATTEMPTED:
2900 		pnfs_write_through_mds(desc, hdr);
2901 		break;
2902 	case PNFS_ATTEMPTED:
2903 		break;
2904 	case PNFS_TRY_AGAIN:
2905 		/* cleanup hdr and prepare to redo pnfs */
2906 		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2907 			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2908 			list_splice_init(&hdr->pages, &mirror->pg_list);
2909 			mirror->pg_recoalesce = 1;
2910 		}
2911 		hdr->mds_ops->rpc_release(hdr);
2912 	}
2913 }
2914 
pnfs_writehdr_free(struct nfs_pgio_header * hdr)2915 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2916 {
2917 	pnfs_put_lseg(hdr->lseg);
2918 	nfs_pgio_header_free(hdr);
2919 }
2920 
2921 int
pnfs_generic_pg_writepages(struct nfs_pageio_descriptor * desc)2922 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2923 {
2924 	struct nfs_pgio_header *hdr;
2925 	int ret;
2926 
2927 	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2928 	if (!hdr) {
2929 		desc->pg_error = -ENOMEM;
2930 		return desc->pg_error;
2931 	}
2932 	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2933 
2934 	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2935 	ret = nfs_generic_pgio(desc, hdr);
2936 	if (!ret)
2937 		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2938 
2939 	return ret;
2940 }
2941 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2942 
pnfs_read_done_resend_to_mds(struct nfs_pgio_header * hdr)2943 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2944 {
2945 	struct nfs_pageio_descriptor pgio;
2946 
2947 	/* Resend all requests through the MDS */
2948 	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2949 	return nfs_pageio_resend(&pgio, hdr);
2950 }
2951 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2952 
pnfs_ld_handle_read_error(struct nfs_pgio_header * hdr)2953 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2954 {
2955 	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2956 	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2957 	    PNFS_LAYOUTRET_ON_ERROR) {
2958 		pnfs_return_layout(hdr->inode);
2959 	}
2960 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2961 		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2962 }
2963 
2964 /*
2965  * Called by non rpc-based layout drivers
2966  */
pnfs_ld_read_done(struct nfs_pgio_header * hdr)2967 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2968 {
2969 	if (likely(!hdr->pnfs_error))
2970 		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2971 	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2972 	if (unlikely(hdr->pnfs_error))
2973 		pnfs_ld_handle_read_error(hdr);
2974 	hdr->mds_ops->rpc_release(hdr);
2975 }
2976 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2977 
2978 static void
pnfs_read_through_mds(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr)2979 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2980 		struct nfs_pgio_header *hdr)
2981 {
2982 	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2983 
2984 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2985 		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2986 		nfs_pageio_reset_read_mds(desc);
2987 		mirror->pg_recoalesce = 1;
2988 	}
2989 	hdr->completion_ops->completion(hdr);
2990 }
2991 
2992 /*
2993  * Call the appropriate parallel I/O subsystem read function.
2994  */
2995 static enum pnfs_try_status
pnfs_try_to_read_data(struct nfs_pgio_header * hdr,const struct rpc_call_ops * call_ops,struct pnfs_layout_segment * lseg)2996 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2997 		       const struct rpc_call_ops *call_ops,
2998 		       struct pnfs_layout_segment *lseg)
2999 {
3000 	struct inode *inode = hdr->inode;
3001 	struct nfs_server *nfss = NFS_SERVER(inode);
3002 	enum pnfs_try_status trypnfs;
3003 
3004 	hdr->mds_ops = call_ops;
3005 
3006 	dprintk("%s: Reading ino:%lu %u@%llu\n",
3007 		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
3008 
3009 	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
3010 	if (trypnfs != PNFS_NOT_ATTEMPTED)
3011 		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
3012 	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3013 	return trypnfs;
3014 }
3015 
3016 /* Resend all requests through pnfs. */
pnfs_read_resend_pnfs(struct nfs_pgio_header * hdr,unsigned int mirror_idx)3017 void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
3018 			   unsigned int mirror_idx)
3019 {
3020 	struct nfs_pageio_descriptor pgio;
3021 
3022 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3023 		/* Prevent deadlocks with layoutreturn! */
3024 		pnfs_put_lseg(hdr->lseg);
3025 		hdr->lseg = NULL;
3026 
3027 		nfs_pageio_init_read(&pgio, hdr->inode, false,
3028 					hdr->completion_ops);
3029 		pgio.pg_mirror_idx = mirror_idx;
3030 		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
3031 	}
3032 }
3033 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
3034 
3035 static void
pnfs_do_read(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr)3036 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
3037 {
3038 	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3039 	struct pnfs_layout_segment *lseg = desc->pg_lseg;
3040 	enum pnfs_try_status trypnfs;
3041 
3042 	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
3043 	switch (trypnfs) {
3044 	case PNFS_NOT_ATTEMPTED:
3045 		pnfs_read_through_mds(desc, hdr);
3046 		break;
3047 	case PNFS_ATTEMPTED:
3048 		break;
3049 	case PNFS_TRY_AGAIN:
3050 		/* cleanup hdr and prepare to redo pnfs */
3051 		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3052 			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3053 			list_splice_init(&hdr->pages, &mirror->pg_list);
3054 			mirror->pg_recoalesce = 1;
3055 		}
3056 		hdr->mds_ops->rpc_release(hdr);
3057 	}
3058 }
3059 
pnfs_readhdr_free(struct nfs_pgio_header * hdr)3060 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
3061 {
3062 	pnfs_put_lseg(hdr->lseg);
3063 	nfs_pgio_header_free(hdr);
3064 }
3065 
3066 int
pnfs_generic_pg_readpages(struct nfs_pageio_descriptor * desc)3067 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
3068 {
3069 	struct nfs_pgio_header *hdr;
3070 	int ret;
3071 
3072 	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3073 	if (!hdr) {
3074 		desc->pg_error = -ENOMEM;
3075 		return desc->pg_error;
3076 	}
3077 	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3078 	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3079 	ret = nfs_generic_pgio(desc, hdr);
3080 	if (!ret)
3081 		pnfs_do_read(desc, hdr);
3082 	return ret;
3083 }
3084 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3085 
pnfs_clear_layoutcommitting(struct inode * inode)3086 static void pnfs_clear_layoutcommitting(struct inode *inode)
3087 {
3088 	unsigned long *bitlock = &NFS_I(inode)->flags;
3089 
3090 	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3091 	smp_mb__after_atomic();
3092 	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3093 }
3094 
3095 /*
3096  * There can be multiple RW segments.
3097  */
pnfs_list_write_lseg(struct inode * inode,struct list_head * listp)3098 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3099 {
3100 	struct pnfs_layout_segment *lseg;
3101 
3102 	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3103 		if (lseg->pls_range.iomode == IOMODE_RW &&
3104 		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3105 			list_add(&lseg->pls_lc_list, listp);
3106 	}
3107 }
3108 
pnfs_list_write_lseg_done(struct inode * inode,struct list_head * listp)3109 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3110 {
3111 	struct pnfs_layout_segment *lseg, *tmp;
3112 
3113 	/* Matched by references in pnfs_set_layoutcommit */
3114 	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3115 		list_del_init(&lseg->pls_lc_list);
3116 		pnfs_put_lseg(lseg);
3117 	}
3118 
3119 	pnfs_clear_layoutcommitting(inode);
3120 }
3121 
pnfs_set_lo_fail(struct pnfs_layout_segment * lseg)3122 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3123 {
3124 	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3125 }
3126 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3127 
3128 void
pnfs_set_layoutcommit(struct inode * inode,struct pnfs_layout_segment * lseg,loff_t end_pos)3129 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3130 		loff_t end_pos)
3131 {
3132 	struct nfs_inode *nfsi = NFS_I(inode);
3133 	bool mark_as_dirty = false;
3134 
3135 	spin_lock(&inode->i_lock);
3136 	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3137 		nfsi->layout->plh_lwb = end_pos;
3138 		mark_as_dirty = true;
3139 		dprintk("%s: Set layoutcommit for inode %lu ",
3140 			__func__, inode->i_ino);
3141 	} else if (end_pos > nfsi->layout->plh_lwb)
3142 		nfsi->layout->plh_lwb = end_pos;
3143 	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3144 		/* references matched in nfs4_layoutcommit_release */
3145 		pnfs_get_lseg(lseg);
3146 	}
3147 	spin_unlock(&inode->i_lock);
3148 	dprintk("%s: lseg %p end_pos %llu\n",
3149 		__func__, lseg, nfsi->layout->plh_lwb);
3150 
3151 	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3152 	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3153 	if (mark_as_dirty)
3154 		mark_inode_dirty_sync(inode);
3155 }
3156 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3157 
pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data * data)3158 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3159 {
3160 	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3161 
3162 	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3163 		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3164 	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3165 }
3166 
3167 /*
3168  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3169  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3170  * data to disk to allow the server to recover the data if it crashes.
3171  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3172  * is off, and a COMMIT is sent to a data server, or
3173  * if WRITEs to a data server return NFS_DATA_SYNC.
3174  */
3175 int
pnfs_layoutcommit_inode(struct inode * inode,bool sync)3176 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3177 {
3178 	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3179 	struct nfs4_layoutcommit_data *data;
3180 	struct nfs_inode *nfsi = NFS_I(inode);
3181 	loff_t end_pos;
3182 	int status;
3183 
3184 	if (!pnfs_layoutcommit_outstanding(inode))
3185 		return 0;
3186 
3187 	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3188 
3189 	status = -EAGAIN;
3190 	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3191 		if (!sync)
3192 			goto out;
3193 		status = wait_on_bit_lock_action(&nfsi->flags,
3194 				NFS_INO_LAYOUTCOMMITTING,
3195 				nfs_wait_bit_killable,
3196 				TASK_KILLABLE);
3197 		if (status)
3198 			goto out;
3199 	}
3200 
3201 	status = -ENOMEM;
3202 	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3203 	data = kzalloc(sizeof(*data), nfs_io_gfp_mask());
3204 	if (!data)
3205 		goto clear_layoutcommitting;
3206 
3207 	status = 0;
3208 	spin_lock(&inode->i_lock);
3209 	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3210 		goto out_unlock;
3211 
3212 	INIT_LIST_HEAD(&data->lseg_list);
3213 	pnfs_list_write_lseg(inode, &data->lseg_list);
3214 
3215 	end_pos = nfsi->layout->plh_lwb;
3216 
3217 	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3218 	data->cred = get_cred(nfsi->layout->plh_lc_cred);
3219 	spin_unlock(&inode->i_lock);
3220 
3221 	data->args.inode = inode;
3222 	nfs_fattr_init(&data->fattr);
3223 	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3224 	data->res.fattr = &data->fattr;
3225 	if (end_pos != 0)
3226 		data->args.lastbytewritten = end_pos - 1;
3227 	else
3228 		data->args.lastbytewritten = U64_MAX;
3229 	data->res.server = NFS_SERVER(inode);
3230 
3231 	if (ld->prepare_layoutcommit) {
3232 		status = ld->prepare_layoutcommit(&data->args);
3233 		if (status) {
3234 			put_cred(data->cred);
3235 			spin_lock(&inode->i_lock);
3236 			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3237 			if (end_pos > nfsi->layout->plh_lwb)
3238 				nfsi->layout->plh_lwb = end_pos;
3239 			goto out_unlock;
3240 		}
3241 	}
3242 
3243 
3244 	status = nfs4_proc_layoutcommit(data, sync);
3245 out:
3246 	if (status)
3247 		mark_inode_dirty_sync(inode);
3248 	dprintk("<-- %s status %d\n", __func__, status);
3249 	return status;
3250 out_unlock:
3251 	spin_unlock(&inode->i_lock);
3252 	kfree(data);
3253 clear_layoutcommitting:
3254 	pnfs_clear_layoutcommitting(inode);
3255 	goto out;
3256 }
3257 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3258 
3259 int
pnfs_generic_sync(struct inode * inode,bool datasync)3260 pnfs_generic_sync(struct inode *inode, bool datasync)
3261 {
3262 	return pnfs_layoutcommit_inode(inode, true);
3263 }
3264 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3265 
pnfs_mdsthreshold_alloc(void)3266 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3267 {
3268 	struct nfs4_threshold *thp;
3269 
3270 	thp = kzalloc(sizeof(*thp), nfs_io_gfp_mask());
3271 	if (!thp) {
3272 		dprintk("%s mdsthreshold allocation failed\n", __func__);
3273 		return NULL;
3274 	}
3275 	return thp;
3276 }
3277 
3278 #if IS_ENABLED(CONFIG_NFS_V4_2)
3279 int
pnfs_report_layoutstat(struct inode * inode,gfp_t gfp_flags)3280 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3281 {
3282 	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3283 	struct nfs_server *server = NFS_SERVER(inode);
3284 	struct nfs_inode *nfsi = NFS_I(inode);
3285 	struct nfs42_layoutstat_data *data;
3286 	struct pnfs_layout_hdr *hdr;
3287 	int status = 0;
3288 
3289 	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3290 		goto out;
3291 
3292 	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3293 		goto out;
3294 
3295 	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3296 		goto out;
3297 
3298 	spin_lock(&inode->i_lock);
3299 	if (!NFS_I(inode)->layout) {
3300 		spin_unlock(&inode->i_lock);
3301 		goto out_clear_layoutstats;
3302 	}
3303 	hdr = NFS_I(inode)->layout;
3304 	pnfs_get_layout_hdr(hdr);
3305 	spin_unlock(&inode->i_lock);
3306 
3307 	data = kzalloc(sizeof(*data), gfp_flags);
3308 	if (!data) {
3309 		status = -ENOMEM;
3310 		goto out_put;
3311 	}
3312 
3313 	data->args.fh = NFS_FH(inode);
3314 	data->args.inode = inode;
3315 	status = ld->prepare_layoutstats(&data->args);
3316 	if (status)
3317 		goto out_free;
3318 
3319 	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3320 
3321 out:
3322 	dprintk("%s returns %d\n", __func__, status);
3323 	return status;
3324 
3325 out_free:
3326 	kfree(data);
3327 out_put:
3328 	pnfs_put_layout_hdr(hdr);
3329 out_clear_layoutstats:
3330 	smp_mb__before_atomic();
3331 	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3332 	smp_mb__after_atomic();
3333 	goto out;
3334 }
3335 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3336 #endif
3337 
3338 unsigned int layoutstats_timer;
3339 module_param(layoutstats_timer, uint, 0644);
3340 EXPORT_SYMBOL_GPL(layoutstats_timer);
3341