xref: /linux/fs/nfs/localio.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * NFS client support for local clients to bypass network stack
4  *
5  * Copyright (C) 2014 Weston Andros Adamson <dros@primarydata.com>
6  * Copyright (C) 2019 Trond Myklebust <trond.myklebust@hammerspace.com>
7  * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
8  * Copyright (C) 2024 NeilBrown <neilb@suse.de>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/vfs.h>
14 #include <linux/file.h>
15 #include <linux/inet.h>
16 #include <linux/sunrpc/addr.h>
17 #include <linux/inetdevice.h>
18 #include <net/addrconf.h>
19 #include <linux/nfs_common.h>
20 #include <linux/nfslocalio.h>
21 #include <linux/bvec.h>
22 
23 #include <linux/nfs.h>
24 #include <linux/nfs_fs.h>
25 #include <linux/nfs_xdr.h>
26 
27 #include "internal.h"
28 #include "pnfs.h"
29 #include "nfstrace.h"
30 
31 #define NFSDBG_FACILITY		NFSDBG_VFS
32 
33 struct nfs_local_kiocb {
34 	struct kiocb		kiocb;
35 	struct bio_vec		*bvec;
36 	struct nfs_pgio_header	*hdr;
37 	struct work_struct	work;
38 	struct nfsd_file	*localio;
39 };
40 
41 struct nfs_local_fsync_ctx {
42 	struct nfsd_file	*localio;
43 	struct nfs_commit_data	*data;
44 	struct work_struct	work;
45 	struct kref		kref;
46 	struct completion	*done;
47 };
48 static void nfs_local_fsync_work(struct work_struct *work);
49 
50 static bool localio_enabled __read_mostly = true;
51 module_param(localio_enabled, bool, 0644);
52 
53 static inline bool nfs_client_is_local(const struct nfs_client *clp)
54 {
55 	return !!test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
56 }
57 
58 bool nfs_server_is_local(const struct nfs_client *clp)
59 {
60 	return nfs_client_is_local(clp) && localio_enabled;
61 }
62 EXPORT_SYMBOL_GPL(nfs_server_is_local);
63 
64 /*
65  * UUID_IS_LOCAL XDR functions
66  */
67 
68 static void localio_xdr_enc_uuidargs(struct rpc_rqst *req,
69 				     struct xdr_stream *xdr,
70 				     const void *data)
71 {
72 	const u8 *uuid = data;
73 
74 	encode_opaque_fixed(xdr, uuid, UUID_SIZE);
75 }
76 
77 static int localio_xdr_dec_uuidres(struct rpc_rqst *req,
78 				   struct xdr_stream *xdr,
79 				   void *result)
80 {
81 	/* void return */
82 	return 0;
83 }
84 
85 static const struct rpc_procinfo nfs_localio_procedures[] = {
86 	[LOCALIOPROC_UUID_IS_LOCAL] = {
87 		.p_proc = LOCALIOPROC_UUID_IS_LOCAL,
88 		.p_encode = localio_xdr_enc_uuidargs,
89 		.p_decode = localio_xdr_dec_uuidres,
90 		.p_arglen = XDR_QUADLEN(UUID_SIZE),
91 		.p_replen = 0,
92 		.p_statidx = LOCALIOPROC_UUID_IS_LOCAL,
93 		.p_name = "UUID_IS_LOCAL",
94 	},
95 };
96 
97 static unsigned int nfs_localio_counts[ARRAY_SIZE(nfs_localio_procedures)];
98 static const struct rpc_version nfslocalio_version1 = {
99 	.number			= 1,
100 	.nrprocs		= ARRAY_SIZE(nfs_localio_procedures),
101 	.procs			= nfs_localio_procedures,
102 	.counts			= nfs_localio_counts,
103 };
104 
105 static const struct rpc_version *nfslocalio_version[] = {
106        [1]			= &nfslocalio_version1,
107 };
108 
109 extern const struct rpc_program nfslocalio_program;
110 static struct rpc_stat		nfslocalio_rpcstat = { &nfslocalio_program };
111 
112 const struct rpc_program nfslocalio_program = {
113 	.name			= "nfslocalio",
114 	.number			= NFS_LOCALIO_PROGRAM,
115 	.nrvers			= ARRAY_SIZE(nfslocalio_version),
116 	.version		= nfslocalio_version,
117 	.stats			= &nfslocalio_rpcstat,
118 };
119 
120 /*
121  * nfs_local_enable - enable local i/o for an nfs_client
122  */
123 static void nfs_local_enable(struct nfs_client *clp)
124 {
125 	spin_lock(&clp->cl_localio_lock);
126 	set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
127 	trace_nfs_local_enable(clp);
128 	spin_unlock(&clp->cl_localio_lock);
129 }
130 
131 /*
132  * nfs_local_disable - disable local i/o for an nfs_client
133  */
134 void nfs_local_disable(struct nfs_client *clp)
135 {
136 	spin_lock(&clp->cl_localio_lock);
137 	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
138 		trace_nfs_local_disable(clp);
139 		nfs_uuid_invalidate_one_client(&clp->cl_uuid);
140 	}
141 	spin_unlock(&clp->cl_localio_lock);
142 }
143 
144 /*
145  * nfs_init_localioclient - Initialise an NFS localio client connection
146  */
147 static struct rpc_clnt *nfs_init_localioclient(struct nfs_client *clp)
148 {
149 	struct rpc_clnt *rpcclient_localio;
150 
151 	rpcclient_localio = rpc_bind_new_program(clp->cl_rpcclient,
152 						 &nfslocalio_program, 1);
153 
154 	dprintk_rcu("%s: server (%s) %s NFS LOCALIO.\n",
155 		__func__, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
156 		(IS_ERR(rpcclient_localio) ? "does not support" : "supports"));
157 
158 	return rpcclient_localio;
159 }
160 
161 static bool nfs_server_uuid_is_local(struct nfs_client *clp)
162 {
163 	u8 uuid[UUID_SIZE];
164 	struct rpc_message msg = {
165 		.rpc_argp = &uuid,
166 	};
167 	struct rpc_clnt *rpcclient_localio;
168 	int status;
169 
170 	rpcclient_localio = nfs_init_localioclient(clp);
171 	if (IS_ERR(rpcclient_localio))
172 		return false;
173 
174 	export_uuid(uuid, &clp->cl_uuid.uuid);
175 
176 	msg.rpc_proc = &nfs_localio_procedures[LOCALIOPROC_UUID_IS_LOCAL];
177 	status = rpc_call_sync(rpcclient_localio, &msg, 0);
178 	dprintk("%s: NFS reply UUID_IS_LOCAL: status=%d\n",
179 		__func__, status);
180 	rpc_shutdown_client(rpcclient_localio);
181 
182 	/* Server is only local if it initialized required struct members */
183 	if (status || !clp->cl_uuid.net || !clp->cl_uuid.dom)
184 		return false;
185 
186 	return true;
187 }
188 
189 /*
190  * nfs_local_probe - probe local i/o support for an nfs_server and nfs_client
191  * - called after alloc_client and init_client (so cl_rpcclient exists)
192  * - this function is idempotent, it can be called for old or new clients
193  */
194 void nfs_local_probe(struct nfs_client *clp)
195 {
196 	/* Disallow localio if disabled via sysfs or AUTH_SYS isn't used */
197 	if (!localio_enabled ||
198 	    clp->cl_rpcclient->cl_auth->au_flavor != RPC_AUTH_UNIX) {
199 		nfs_local_disable(clp);
200 		return;
201 	}
202 
203 	if (nfs_client_is_local(clp)) {
204 		/* If already enabled, disable and re-enable */
205 		nfs_local_disable(clp);
206 	}
207 
208 	nfs_uuid_begin(&clp->cl_uuid);
209 	if (nfs_server_uuid_is_local(clp))
210 		nfs_local_enable(clp);
211 	nfs_uuid_end(&clp->cl_uuid);
212 }
213 EXPORT_SYMBOL_GPL(nfs_local_probe);
214 
215 /*
216  * nfs_local_open_fh - open a local filehandle in terms of nfsd_file
217  *
218  * Returns a pointer to a struct nfsd_file or NULL
219  */
220 struct nfsd_file *
221 nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
222 		  struct nfs_fh *fh, const fmode_t mode)
223 {
224 	struct nfsd_file *localio;
225 	int status;
226 
227 	if (!nfs_server_is_local(clp))
228 		return NULL;
229 	if (mode & ~(FMODE_READ | FMODE_WRITE))
230 		return NULL;
231 
232 	localio = nfs_open_local_fh(&clp->cl_uuid, clp->cl_rpcclient,
233 				    cred, fh, mode);
234 	if (IS_ERR(localio)) {
235 		status = PTR_ERR(localio);
236 		trace_nfs_local_open_fh(fh, mode, status);
237 		switch (status) {
238 		case -ENOMEM:
239 		case -ENXIO:
240 		case -ENOENT:
241 			/* Revalidate localio, will disable if unsupported */
242 			nfs_local_probe(clp);
243 		}
244 		return NULL;
245 	}
246 	return localio;
247 }
248 EXPORT_SYMBOL_GPL(nfs_local_open_fh);
249 
250 static struct bio_vec *
251 nfs_bvec_alloc_and_import_pagevec(struct page **pagevec,
252 		unsigned int npages, gfp_t flags)
253 {
254 	struct bio_vec *bvec, *p;
255 
256 	bvec = kmalloc_array(npages, sizeof(*bvec), flags);
257 	if (bvec != NULL) {
258 		for (p = bvec; npages > 0; p++, pagevec++, npages--) {
259 			p->bv_page = *pagevec;
260 			p->bv_len = PAGE_SIZE;
261 			p->bv_offset = 0;
262 		}
263 	}
264 	return bvec;
265 }
266 
267 static void
268 nfs_local_iocb_free(struct nfs_local_kiocb *iocb)
269 {
270 	kfree(iocb->bvec);
271 	kfree(iocb);
272 }
273 
274 static struct nfs_local_kiocb *
275 nfs_local_iocb_alloc(struct nfs_pgio_header *hdr,
276 		     struct nfsd_file *localio, gfp_t flags)
277 {
278 	struct nfs_local_kiocb *iocb;
279 
280 	iocb = kmalloc(sizeof(*iocb), flags);
281 	if (iocb == NULL)
282 		return NULL;
283 	iocb->bvec = nfs_bvec_alloc_and_import_pagevec(hdr->page_array.pagevec,
284 			hdr->page_array.npages, flags);
285 	if (iocb->bvec == NULL) {
286 		kfree(iocb);
287 		return NULL;
288 	}
289 	init_sync_kiocb(&iocb->kiocb, nfs_to->nfsd_file_file(localio));
290 	iocb->kiocb.ki_pos = hdr->args.offset;
291 	iocb->localio = localio;
292 	iocb->hdr = hdr;
293 	iocb->kiocb.ki_flags &= ~IOCB_APPEND;
294 	return iocb;
295 }
296 
297 static void
298 nfs_local_iter_init(struct iov_iter *i, struct nfs_local_kiocb *iocb, int dir)
299 {
300 	struct nfs_pgio_header *hdr = iocb->hdr;
301 
302 	iov_iter_bvec(i, dir, iocb->bvec, hdr->page_array.npages,
303 		      hdr->args.count + hdr->args.pgbase);
304 	if (hdr->args.pgbase != 0)
305 		iov_iter_advance(i, hdr->args.pgbase);
306 }
307 
308 static void
309 nfs_local_hdr_release(struct nfs_pgio_header *hdr,
310 		const struct rpc_call_ops *call_ops)
311 {
312 	call_ops->rpc_call_done(&hdr->task, hdr);
313 	call_ops->rpc_release(hdr);
314 }
315 
316 static void
317 nfs_local_pgio_init(struct nfs_pgio_header *hdr,
318 		const struct rpc_call_ops *call_ops)
319 {
320 	hdr->task.tk_ops = call_ops;
321 	if (!hdr->task.tk_start)
322 		hdr->task.tk_start = ktime_get();
323 }
324 
325 static void
326 nfs_local_pgio_done(struct nfs_pgio_header *hdr, long status)
327 {
328 	if (status >= 0) {
329 		hdr->res.count = status;
330 		hdr->res.op_status = NFS4_OK;
331 		hdr->task.tk_status = 0;
332 	} else {
333 		hdr->res.op_status = nfs4_stat_to_errno(status);
334 		hdr->task.tk_status = status;
335 	}
336 }
337 
338 static void
339 nfs_local_pgio_release(struct nfs_local_kiocb *iocb)
340 {
341 	struct nfs_pgio_header *hdr = iocb->hdr;
342 
343 	nfs_to_nfsd_file_put_local(iocb->localio);
344 	nfs_local_iocb_free(iocb);
345 	nfs_local_hdr_release(hdr, hdr->task.tk_ops);
346 }
347 
348 static void
349 nfs_local_read_done(struct nfs_local_kiocb *iocb, long status)
350 {
351 	struct nfs_pgio_header *hdr = iocb->hdr;
352 	struct file *filp = iocb->kiocb.ki_filp;
353 
354 	nfs_local_pgio_done(hdr, status);
355 
356 	if (hdr->res.count != hdr->args.count ||
357 	    hdr->args.offset + hdr->res.count >= i_size_read(file_inode(filp)))
358 		hdr->res.eof = true;
359 
360 	dprintk("%s: read %ld bytes eof %d.\n", __func__,
361 			status > 0 ? status : 0, hdr->res.eof);
362 }
363 
364 static void nfs_local_call_read(struct work_struct *work)
365 {
366 	struct nfs_local_kiocb *iocb =
367 		container_of(work, struct nfs_local_kiocb, work);
368 	struct file *filp = iocb->kiocb.ki_filp;
369 	const struct cred *save_cred;
370 	struct iov_iter iter;
371 	ssize_t status;
372 
373 	save_cred = override_creds(filp->f_cred);
374 
375 	nfs_local_iter_init(&iter, iocb, READ);
376 
377 	status = filp->f_op->read_iter(&iocb->kiocb, &iter);
378 	WARN_ON_ONCE(status == -EIOCBQUEUED);
379 
380 	nfs_local_read_done(iocb, status);
381 	nfs_local_pgio_release(iocb);
382 
383 	revert_creds(save_cred);
384 }
385 
386 static int
387 nfs_do_local_read(struct nfs_pgio_header *hdr,
388 		  struct nfsd_file *localio,
389 		  const struct rpc_call_ops *call_ops)
390 {
391 	struct nfs_local_kiocb *iocb;
392 
393 	dprintk("%s: vfs_read count=%u pos=%llu\n",
394 		__func__, hdr->args.count, hdr->args.offset);
395 
396 	iocb = nfs_local_iocb_alloc(hdr, localio, GFP_KERNEL);
397 	if (iocb == NULL)
398 		return -ENOMEM;
399 
400 	nfs_local_pgio_init(hdr, call_ops);
401 	hdr->res.eof = false;
402 
403 	INIT_WORK(&iocb->work, nfs_local_call_read);
404 	queue_work(nfslocaliod_workqueue, &iocb->work);
405 
406 	return 0;
407 }
408 
409 static void
410 nfs_copy_boot_verifier(struct nfs_write_verifier *verifier, struct inode *inode)
411 {
412 	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
413 	u32 *verf = (u32 *)verifier->data;
414 	int seq = 0;
415 
416 	do {
417 		read_seqbegin_or_lock(&clp->cl_boot_lock, &seq);
418 		verf[0] = (u32)clp->cl_nfssvc_boot.tv_sec;
419 		verf[1] = (u32)clp->cl_nfssvc_boot.tv_nsec;
420 	} while (need_seqretry(&clp->cl_boot_lock, seq));
421 	done_seqretry(&clp->cl_boot_lock, seq);
422 }
423 
424 static void
425 nfs_reset_boot_verifier(struct inode *inode)
426 {
427 	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
428 
429 	write_seqlock(&clp->cl_boot_lock);
430 	ktime_get_real_ts64(&clp->cl_nfssvc_boot);
431 	write_sequnlock(&clp->cl_boot_lock);
432 }
433 
434 static void
435 nfs_set_local_verifier(struct inode *inode,
436 		struct nfs_writeverf *verf,
437 		enum nfs3_stable_how how)
438 {
439 	nfs_copy_boot_verifier(&verf->verifier, inode);
440 	verf->committed = how;
441 }
442 
443 /* Factored out from fs/nfsd/vfs.h:fh_getattr() */
444 static int __vfs_getattr(struct path *p, struct kstat *stat, int version)
445 {
446 	u32 request_mask = STATX_BASIC_STATS;
447 
448 	if (version == 4)
449 		request_mask |= (STATX_BTIME | STATX_CHANGE_COOKIE);
450 	return vfs_getattr(p, stat, request_mask, AT_STATX_SYNC_AS_STAT);
451 }
452 
453 /* Copied from fs/nfsd/nfsfh.c:nfsd4_change_attribute() */
454 static u64 __nfsd4_change_attribute(const struct kstat *stat,
455 				    const struct inode *inode)
456 {
457 	u64 chattr;
458 
459 	if (stat->result_mask & STATX_CHANGE_COOKIE) {
460 		chattr = stat->change_cookie;
461 		if (S_ISREG(inode->i_mode) &&
462 		    !(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) {
463 			chattr += (u64)stat->ctime.tv_sec << 30;
464 			chattr += stat->ctime.tv_nsec;
465 		}
466 	} else {
467 		chattr = time_to_chattr(&stat->ctime);
468 	}
469 	return chattr;
470 }
471 
472 static void nfs_local_vfs_getattr(struct nfs_local_kiocb *iocb)
473 {
474 	struct kstat stat;
475 	struct file *filp = iocb->kiocb.ki_filp;
476 	struct nfs_pgio_header *hdr = iocb->hdr;
477 	struct nfs_fattr *fattr = hdr->res.fattr;
478 	int version = NFS_PROTO(hdr->inode)->version;
479 
480 	if (unlikely(!fattr) || __vfs_getattr(&filp->f_path, &stat, version))
481 		return;
482 
483 	fattr->valid = (NFS_ATTR_FATTR_FILEID |
484 			NFS_ATTR_FATTR_CHANGE |
485 			NFS_ATTR_FATTR_SIZE |
486 			NFS_ATTR_FATTR_ATIME |
487 			NFS_ATTR_FATTR_MTIME |
488 			NFS_ATTR_FATTR_CTIME |
489 			NFS_ATTR_FATTR_SPACE_USED);
490 
491 	fattr->fileid = stat.ino;
492 	fattr->size = stat.size;
493 	fattr->atime = stat.atime;
494 	fattr->mtime = stat.mtime;
495 	fattr->ctime = stat.ctime;
496 	if (version == 4) {
497 		fattr->change_attr =
498 			__nfsd4_change_attribute(&stat, file_inode(filp));
499 	} else
500 		fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
501 	fattr->du.nfs3.used = stat.blocks << 9;
502 }
503 
504 static void
505 nfs_local_write_done(struct nfs_local_kiocb *iocb, long status)
506 {
507 	struct nfs_pgio_header *hdr = iocb->hdr;
508 	struct inode *inode = hdr->inode;
509 
510 	dprintk("%s: wrote %ld bytes.\n", __func__, status > 0 ? status : 0);
511 
512 	/* Handle short writes as if they are ENOSPC */
513 	if (status > 0 && status < hdr->args.count) {
514 		hdr->mds_offset += status;
515 		hdr->args.offset += status;
516 		hdr->args.pgbase += status;
517 		hdr->args.count -= status;
518 		nfs_set_pgio_error(hdr, -ENOSPC, hdr->args.offset);
519 		status = -ENOSPC;
520 	}
521 	if (status < 0)
522 		nfs_reset_boot_verifier(inode);
523 	else if (nfs_should_remove_suid(inode)) {
524 		/* Deal with the suid/sgid bit corner case */
525 		spin_lock(&inode->i_lock);
526 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
527 		spin_unlock(&inode->i_lock);
528 	}
529 	nfs_local_pgio_done(hdr, status);
530 }
531 
532 static void nfs_local_call_write(struct work_struct *work)
533 {
534 	struct nfs_local_kiocb *iocb =
535 		container_of(work, struct nfs_local_kiocb, work);
536 	struct file *filp = iocb->kiocb.ki_filp;
537 	unsigned long old_flags = current->flags;
538 	const struct cred *save_cred;
539 	struct iov_iter iter;
540 	ssize_t status;
541 
542 	current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO;
543 	save_cred = override_creds(filp->f_cred);
544 
545 	nfs_local_iter_init(&iter, iocb, WRITE);
546 
547 	file_start_write(filp);
548 	status = filp->f_op->write_iter(&iocb->kiocb, &iter);
549 	file_end_write(filp);
550 	WARN_ON_ONCE(status == -EIOCBQUEUED);
551 
552 	nfs_local_write_done(iocb, status);
553 	nfs_local_vfs_getattr(iocb);
554 	nfs_local_pgio_release(iocb);
555 
556 	revert_creds(save_cred);
557 	current->flags = old_flags;
558 }
559 
560 static int
561 nfs_do_local_write(struct nfs_pgio_header *hdr,
562 		   struct nfsd_file *localio,
563 		   const struct rpc_call_ops *call_ops)
564 {
565 	struct nfs_local_kiocb *iocb;
566 
567 	dprintk("%s: vfs_write count=%u pos=%llu %s\n",
568 		__func__, hdr->args.count, hdr->args.offset,
569 		(hdr->args.stable == NFS_UNSTABLE) ?  "unstable" : "stable");
570 
571 	iocb = nfs_local_iocb_alloc(hdr, localio, GFP_NOIO);
572 	if (iocb == NULL)
573 		return -ENOMEM;
574 
575 	switch (hdr->args.stable) {
576 	default:
577 		break;
578 	case NFS_DATA_SYNC:
579 		iocb->kiocb.ki_flags |= IOCB_DSYNC;
580 		break;
581 	case NFS_FILE_SYNC:
582 		iocb->kiocb.ki_flags |= IOCB_DSYNC|IOCB_SYNC;
583 	}
584 	nfs_local_pgio_init(hdr, call_ops);
585 
586 	nfs_set_local_verifier(hdr->inode, hdr->res.verf, hdr->args.stable);
587 
588 	INIT_WORK(&iocb->work, nfs_local_call_write);
589 	queue_work(nfslocaliod_workqueue, &iocb->work);
590 
591 	return 0;
592 }
593 
594 int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
595 		   struct nfs_pgio_header *hdr,
596 		   const struct rpc_call_ops *call_ops)
597 {
598 	int status = 0;
599 	struct file *filp = nfs_to->nfsd_file_file(localio);
600 
601 	if (!hdr->args.count)
602 		return 0;
603 	/* Don't support filesystems without read_iter/write_iter */
604 	if (!filp->f_op->read_iter || !filp->f_op->write_iter) {
605 		nfs_local_disable(clp);
606 		status = -EAGAIN;
607 		goto out;
608 	}
609 
610 	switch (hdr->rw_mode) {
611 	case FMODE_READ:
612 		status = nfs_do_local_read(hdr, localio, call_ops);
613 		break;
614 	case FMODE_WRITE:
615 		status = nfs_do_local_write(hdr, localio, call_ops);
616 		break;
617 	default:
618 		dprintk("%s: invalid mode: %d\n", __func__,
619 			hdr->rw_mode);
620 		status = -EINVAL;
621 	}
622 out:
623 	if (status != 0) {
624 		nfs_to_nfsd_file_put_local(localio);
625 		hdr->task.tk_status = status;
626 		nfs_local_hdr_release(hdr, call_ops);
627 	}
628 	return status;
629 }
630 
631 static void
632 nfs_local_init_commit(struct nfs_commit_data *data,
633 		const struct rpc_call_ops *call_ops)
634 {
635 	data->task.tk_ops = call_ops;
636 }
637 
638 static int
639 nfs_local_run_commit(struct file *filp, struct nfs_commit_data *data)
640 {
641 	loff_t start = data->args.offset;
642 	loff_t end = LLONG_MAX;
643 
644 	if (data->args.count > 0) {
645 		end = start + data->args.count - 1;
646 		if (end < start)
647 			end = LLONG_MAX;
648 	}
649 
650 	dprintk("%s: commit %llu - %llu\n", __func__, start, end);
651 	return vfs_fsync_range(filp, start, end, 0);
652 }
653 
654 static void
655 nfs_local_commit_done(struct nfs_commit_data *data, int status)
656 {
657 	if (status >= 0) {
658 		nfs_set_local_verifier(data->inode,
659 				data->res.verf,
660 				NFS_FILE_SYNC);
661 		data->res.op_status = NFS4_OK;
662 		data->task.tk_status = 0;
663 	} else {
664 		nfs_reset_boot_verifier(data->inode);
665 		data->res.op_status = nfs4_stat_to_errno(status);
666 		data->task.tk_status = status;
667 	}
668 }
669 
670 static void
671 nfs_local_release_commit_data(struct nfsd_file *localio,
672 		struct nfs_commit_data *data,
673 		const struct rpc_call_ops *call_ops)
674 {
675 	nfs_to_nfsd_file_put_local(localio);
676 	call_ops->rpc_call_done(&data->task, data);
677 	call_ops->rpc_release(data);
678 }
679 
680 static struct nfs_local_fsync_ctx *
681 nfs_local_fsync_ctx_alloc(struct nfs_commit_data *data,
682 			  struct nfsd_file *localio, gfp_t flags)
683 {
684 	struct nfs_local_fsync_ctx *ctx = kmalloc(sizeof(*ctx), flags);
685 
686 	if (ctx != NULL) {
687 		ctx->localio = localio;
688 		ctx->data = data;
689 		INIT_WORK(&ctx->work, nfs_local_fsync_work);
690 		kref_init(&ctx->kref);
691 		ctx->done = NULL;
692 	}
693 	return ctx;
694 }
695 
696 static void
697 nfs_local_fsync_ctx_kref_free(struct kref *kref)
698 {
699 	kfree(container_of(kref, struct nfs_local_fsync_ctx, kref));
700 }
701 
702 static void
703 nfs_local_fsync_ctx_put(struct nfs_local_fsync_ctx *ctx)
704 {
705 	kref_put(&ctx->kref, nfs_local_fsync_ctx_kref_free);
706 }
707 
708 static void
709 nfs_local_fsync_ctx_free(struct nfs_local_fsync_ctx *ctx)
710 {
711 	nfs_local_release_commit_data(ctx->localio, ctx->data,
712 				      ctx->data->task.tk_ops);
713 	nfs_local_fsync_ctx_put(ctx);
714 }
715 
716 static void
717 nfs_local_fsync_work(struct work_struct *work)
718 {
719 	struct nfs_local_fsync_ctx *ctx;
720 	int status;
721 
722 	ctx = container_of(work, struct nfs_local_fsync_ctx, work);
723 
724 	status = nfs_local_run_commit(nfs_to->nfsd_file_file(ctx->localio),
725 				      ctx->data);
726 	nfs_local_commit_done(ctx->data, status);
727 	if (ctx->done != NULL)
728 		complete(ctx->done);
729 	nfs_local_fsync_ctx_free(ctx);
730 }
731 
732 int nfs_local_commit(struct nfsd_file *localio,
733 		     struct nfs_commit_data *data,
734 		     const struct rpc_call_ops *call_ops, int how)
735 {
736 	struct nfs_local_fsync_ctx *ctx;
737 
738 	ctx = nfs_local_fsync_ctx_alloc(data, localio, GFP_KERNEL);
739 	if (!ctx) {
740 		nfs_local_commit_done(data, -ENOMEM);
741 		nfs_local_release_commit_data(localio, data, call_ops);
742 		return -ENOMEM;
743 	}
744 
745 	nfs_local_init_commit(data, call_ops);
746 	kref_get(&ctx->kref);
747 	if (how & FLUSH_SYNC) {
748 		DECLARE_COMPLETION_ONSTACK(done);
749 		ctx->done = &done;
750 		queue_work(nfsiod_workqueue, &ctx->work);
751 		wait_for_completion(&done);
752 	} else
753 		queue_work(nfsiod_workqueue, &ctx->work);
754 	nfs_local_fsync_ctx_put(ctx);
755 	return 0;
756 }
757