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v5.14.15
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/nfs/file.c
  4 *
  5 *  Copyright (C) 1992  Rick Sladkey
  6 */
  7#include <linux/fs.h>
  8#include <linux/file.h>
  9#include <linux/falloc.h>
 10#include <linux/mount.h>
 11#include <linux/nfs_fs.h>
 12#include <linux/nfs_ssc.h>
 13#include "delegation.h"
 14#include "internal.h"
 15#include "iostat.h"
 16#include "fscache.h"
 17#include "pnfs.h"
 18
 19#include "nfstrace.h"
 20
 21#ifdef CONFIG_NFS_V4_2
 22#include "nfs42.h"
 23#endif
 24
 25#define NFSDBG_FACILITY		NFSDBG_FILE
 26
 27static int
 28nfs4_file_open(struct inode *inode, struct file *filp)
 29{
 30	struct nfs_open_context *ctx;
 31	struct dentry *dentry = file_dentry(filp);
 32	struct dentry *parent = NULL;
 33	struct inode *dir;
 34	unsigned openflags = filp->f_flags;
 35	struct iattr attr;
 36	int err;
 37
 38	/*
 39	 * If no cached dentry exists or if it's negative, NFSv4 handled the
 40	 * opens in ->lookup() or ->create().
 41	 *
 42	 * We only get this far for a cached positive dentry.  We skipped
 43	 * revalidation, so handle it here by dropping the dentry and returning
 44	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 45	 */
 46
 47	dprintk("NFS: open file(%pd2)\n", dentry);
 48
 49	err = nfs_check_flags(openflags);
 50	if (err)
 51		return err;
 52
 53	if ((openflags & O_ACCMODE) == 3)
 54		return nfs_open(inode, filp);
 55
 56	/* We can't create new files here */
 57	openflags &= ~(O_CREAT|O_EXCL);
 58
 59	parent = dget_parent(dentry);
 60	dir = d_inode(parent);
 61
 62	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
 
 63	err = PTR_ERR(ctx);
 64	if (IS_ERR(ctx))
 65		goto out;
 66
 67	attr.ia_valid = ATTR_OPEN;
 68	if (openflags & O_TRUNC) {
 69		attr.ia_valid |= ATTR_SIZE;
 70		attr.ia_size = 0;
 71		filemap_write_and_wait(inode->i_mapping);
 72	}
 73
 74	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
 75	if (IS_ERR(inode)) {
 76		err = PTR_ERR(inode);
 77		switch (err) {
 78		default:
 79			goto out_put_ctx;
 80		case -ENOENT:
 81		case -ESTALE:
 82		case -EISDIR:
 83		case -ENOTDIR:
 84		case -ELOOP:
 85			goto out_drop;
 86		}
 87	}
 88	if (inode != d_inode(dentry))
 89		goto out_drop;
 90
 91	nfs_file_set_open_context(filp, ctx);
 92	nfs_fscache_open_file(inode, filp);
 93	err = 0;
 
 94
 95out_put_ctx:
 96	put_nfs_open_context(ctx);
 97out:
 98	dput(parent);
 99	return err;
100
101out_drop:
102	d_drop(dentry);
103	err = -EOPENSTALE;
104	goto out_put_ctx;
105}
106
107/*
108 * Flush all dirty pages, and check for write errors.
109 */
110static int
111nfs4_file_flush(struct file *file, fl_owner_t id)
112{
113	struct inode	*inode = file_inode(file);
114	errseq_t since;
115
116	dprintk("NFS: flush(%pD2)\n", file);
117
118	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
119	if ((file->f_mode & FMODE_WRITE) == 0)
120		return 0;
121
122	/*
123	 * If we're holding a write delegation, then check if we're required
124	 * to flush the i/o on close. If not, then just start the i/o now.
125	 */
126	if (!nfs4_delegation_flush_on_close(inode))
127		return filemap_fdatawrite(file->f_mapping);
128
129	/* Flush writes to the server and return any errors */
130	since = filemap_sample_wb_err(file->f_mapping);
131	nfs_wb_all(inode);
132	return filemap_check_wb_err(file->f_mapping, since);
133}
134
135#ifdef CONFIG_NFS_V4_2
136static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
137				      struct file *file_out, loff_t pos_out,
138				      size_t count, unsigned int flags)
139{
140	struct nfs42_copy_notify_res *cn_resp = NULL;
141	struct nl4_server *nss = NULL;
142	nfs4_stateid *cnrs = NULL;
143	ssize_t ret;
144	bool sync = false;
145
146	/* Only offload copy if superblock is the same */
147	if (file_in->f_op != &nfs4_file_operations)
148		return -EXDEV;
149	if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
150	    !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
151		return -EOPNOTSUPP;
152	if (file_inode(file_in) == file_inode(file_out))
153		return -EOPNOTSUPP;
154	/* if the copy size if smaller than 2 RPC payloads, make it
155	 * synchronous
156	 */
157	if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
158		sync = true;
159retry:
160	if (!nfs42_files_from_same_server(file_in, file_out)) {
161		/* for inter copy, if copy size if smaller than 12 RPC
162		 * payloads, fallback to traditional copy. There are
163		 * 14 RPCs during an NFSv4.x mount between source/dest
164		 * servers.
165		 */
166		if (sync ||
167			count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
168			return -EOPNOTSUPP;
169		cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
170				GFP_NOFS);
171		if (unlikely(cn_resp == NULL))
172			return -ENOMEM;
173
174		ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
175		if (ret) {
176			ret = -EOPNOTSUPP;
177			goto out;
178		}
179		nss = &cn_resp->cnr_src;
180		cnrs = &cn_resp->cnr_stateid;
181	}
182	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
183				nss, cnrs, sync);
184out:
185	if (!nfs42_files_from_same_server(file_in, file_out))
186		kfree(cn_resp);
187	if (ret == -EAGAIN)
188		goto retry;
189	return ret;
190}
191
192static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
193				    struct file *file_out, loff_t pos_out,
194				    size_t count, unsigned int flags)
195{
196	ssize_t ret;
197
198	ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
199				     flags);
200	if (ret == -EOPNOTSUPP || ret == -EXDEV)
201		ret = generic_copy_file_range(file_in, pos_in, file_out,
202					      pos_out, count, flags);
203	return ret;
204}
205
206static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
207{
208	loff_t ret;
209
210	switch (whence) {
211	case SEEK_HOLE:
212	case SEEK_DATA:
213		ret = nfs42_proc_llseek(filep, offset, whence);
214		if (ret != -EOPNOTSUPP)
215			return ret;
216		fallthrough;
217	default:
218		return nfs_file_llseek(filep, offset, whence);
219	}
220}
221
222static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
223{
224	struct inode *inode = file_inode(filep);
225	long ret;
226
227	if (!S_ISREG(inode->i_mode))
228		return -EOPNOTSUPP;
229
230	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
231		return -EOPNOTSUPP;
232
233	ret = inode_newsize_ok(inode, offset + len);
234	if (ret < 0)
235		return ret;
236
237	if (mode & FALLOC_FL_PUNCH_HOLE)
238		return nfs42_proc_deallocate(filep, offset, len);
239	return nfs42_proc_allocate(filep, offset, len);
240}
241
242static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
243		struct file *dst_file, loff_t dst_off, loff_t count,
244		unsigned int remap_flags)
245{
246	struct inode *dst_inode = file_inode(dst_file);
247	struct nfs_server *server = NFS_SERVER(dst_inode);
248	struct inode *src_inode = file_inode(src_file);
249	unsigned int bs = server->clone_blksize;
250	bool same_inode = false;
251	int ret;
252
253	/* NFS does not support deduplication. */
254	if (remap_flags & REMAP_FILE_DEDUP)
255		return -EOPNOTSUPP;
256
257	if (remap_flags & ~REMAP_FILE_ADVISORY)
258		return -EINVAL;
259
260	if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
261		return -ETXTBSY;
262
263	/* check alignment w.r.t. clone_blksize */
264	ret = -EINVAL;
265	if (bs) {
266		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
267			goto out;
268		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
269			goto out;
270	}
271
272	if (src_inode == dst_inode)
273		same_inode = true;
274
275	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
276	if (same_inode) {
277		inode_lock(src_inode);
278	} else if (dst_inode < src_inode) {
279		inode_lock_nested(dst_inode, I_MUTEX_PARENT);
280		inode_lock_nested(src_inode, I_MUTEX_CHILD);
281	} else {
282		inode_lock_nested(src_inode, I_MUTEX_PARENT);
283		inode_lock_nested(dst_inode, I_MUTEX_CHILD);
284	}
285
286	/* flush all pending writes on both src and dst so that server
287	 * has the latest data */
288	ret = nfs_sync_inode(src_inode);
289	if (ret)
290		goto out_unlock;
291	ret = nfs_sync_inode(dst_inode);
292	if (ret)
293		goto out_unlock;
294
295	ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
296
297	/* truncate inode page cache of the dst range so that future reads can fetch
298	 * new data from server */
299	if (!ret)
300		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
301
302out_unlock:
303	if (same_inode) {
304		inode_unlock(src_inode);
305	} else if (dst_inode < src_inode) {
306		inode_unlock(src_inode);
307		inode_unlock(dst_inode);
308	} else {
309		inode_unlock(dst_inode);
310		inode_unlock(src_inode);
311	}
312out:
313	return ret < 0 ? ret : count;
314}
315
316static int read_name_gen = 1;
317#define SSC_READ_NAME_BODY "ssc_read_%d"
318
319static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
320		struct nfs_fh *src_fh, nfs4_stateid *stateid)
321{
322	struct nfs_fattr fattr;
323	struct file *filep, *res;
324	struct nfs_server *server;
325	struct inode *r_ino = NULL;
326	struct nfs_open_context *ctx;
327	struct nfs4_state_owner *sp;
328	char *read_name = NULL;
329	int len, status = 0;
330
331	server = NFS_SERVER(ss_mnt->mnt_root->d_inode);
332
333	nfs_fattr_init(&fattr);
 
334
335	status = nfs4_proc_getattr(server, src_fh, &fattr, NULL, NULL);
336	if (status < 0) {
337		res = ERR_PTR(status);
338		goto out;
339	}
340
 
 
 
 
 
341	res = ERR_PTR(-ENOMEM);
342	len = strlen(SSC_READ_NAME_BODY) + 16;
343	read_name = kzalloc(len, GFP_NOFS);
344	if (read_name == NULL)
345		goto out;
346	snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
347
348	r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, &fattr,
349			NULL);
350	if (IS_ERR(r_ino)) {
351		res = ERR_CAST(r_ino);
352		goto out_free_name;
353	}
354
355	filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
356				     r_ino->i_fop);
357	if (IS_ERR(filep)) {
358		res = ERR_CAST(filep);
 
359		goto out_free_name;
360	}
361	filep->f_mode |= FMODE_READ;
362
363	ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
364					filep);
365	if (IS_ERR(ctx)) {
366		res = ERR_CAST(ctx);
367		goto out_filep;
368	}
369
370	res = ERR_PTR(-EINVAL);
371	sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
372	if (sp == NULL)
373		goto out_ctx;
374
375	ctx->state = nfs4_get_open_state(r_ino, sp);
376	if (ctx->state == NULL)
377		goto out_stateowner;
378
379	set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
380	memcpy(&ctx->state->open_stateid.other, &stateid->other,
381	       NFS4_STATEID_OTHER_SIZE);
382	update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
383	set_bit(NFS_OPEN_STATE, &ctx->state->flags);
384
385	nfs_file_set_open_context(filep, ctx);
386	put_nfs_open_context(ctx);
387
388	file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
389	res = filep;
390out_free_name:
391	kfree(read_name);
392out:
 
393	return res;
394out_stateowner:
395	nfs4_put_state_owner(sp);
396out_ctx:
397	put_nfs_open_context(ctx);
398out_filep:
399	fput(filep);
400	goto out_free_name;
401}
402
403static void __nfs42_ssc_close(struct file *filep)
404{
405	struct nfs_open_context *ctx = nfs_file_open_context(filep);
406
407	ctx->state->flags = 0;
408}
409
410static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
411	.sco_open = __nfs42_ssc_open,
412	.sco_close = __nfs42_ssc_close,
413};
414
415/**
416 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
417 *
418 * Return values:
419 *   None
420 */
421void nfs42_ssc_register_ops(void)
422{
423	nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
424}
425
426/**
427 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
428 *
429 * Return values:
430 *   None.
431 */
432void nfs42_ssc_unregister_ops(void)
433{
434	nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
435}
436#endif /* CONFIG_NFS_V4_2 */
437
438static int nfs4_setlease(struct file *file, long arg, struct file_lock **lease,
439			 void **priv)
440{
441	return nfs4_proc_setlease(file, arg, lease, priv);
442}
443
444const struct file_operations nfs4_file_operations = {
445	.read_iter	= nfs_file_read,
446	.write_iter	= nfs_file_write,
447	.mmap		= nfs_file_mmap,
448	.open		= nfs4_file_open,
449	.flush		= nfs4_file_flush,
450	.release	= nfs_file_release,
451	.fsync		= nfs_file_fsync,
452	.lock		= nfs_lock,
453	.flock		= nfs_flock,
454	.splice_read	= generic_file_splice_read,
455	.splice_write	= iter_file_splice_write,
456	.check_flags	= nfs_check_flags,
457	.setlease	= nfs4_setlease,
458#ifdef CONFIG_NFS_V4_2
459	.copy_file_range = nfs4_copy_file_range,
460	.llseek		= nfs4_file_llseek,
461	.fallocate	= nfs42_fallocate,
462	.remap_file_range = nfs42_remap_file_range,
463#else
464	.llseek		= nfs_file_llseek,
465#endif
466};
v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/nfs/file.c
  4 *
  5 *  Copyright (C) 1992  Rick Sladkey
  6 */
  7#include <linux/fs.h>
  8#include <linux/file.h>
  9#include <linux/falloc.h>
 10#include <linux/mount.h>
 11#include <linux/nfs_fs.h>
 12#include <linux/nfs_ssc.h>
 13#include "delegation.h"
 14#include "internal.h"
 15#include "iostat.h"
 16#include "fscache.h"
 17#include "pnfs.h"
 18
 19#include "nfstrace.h"
 20
 21#ifdef CONFIG_NFS_V4_2
 22#include "nfs42.h"
 23#endif
 24
 25#define NFSDBG_FACILITY		NFSDBG_FILE
 26
 27static int
 28nfs4_file_open(struct inode *inode, struct file *filp)
 29{
 30	struct nfs_open_context *ctx;
 31	struct dentry *dentry = file_dentry(filp);
 32	struct dentry *parent = NULL;
 33	struct inode *dir;
 34	unsigned openflags = filp->f_flags;
 35	struct iattr attr;
 36	int err;
 37
 38	/*
 39	 * If no cached dentry exists or if it's negative, NFSv4 handled the
 40	 * opens in ->lookup() or ->create().
 41	 *
 42	 * We only get this far for a cached positive dentry.  We skipped
 43	 * revalidation, so handle it here by dropping the dentry and returning
 44	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 45	 */
 46
 47	dprintk("NFS: open file(%pd2)\n", dentry);
 48
 49	err = nfs_check_flags(openflags);
 50	if (err)
 51		return err;
 52
 
 
 
 53	/* We can't create new files here */
 54	openflags &= ~(O_CREAT|O_EXCL);
 55
 56	parent = dget_parent(dentry);
 57	dir = d_inode(parent);
 58
 59	ctx = alloc_nfs_open_context(file_dentry(filp),
 60				     flags_to_mode(openflags), filp);
 61	err = PTR_ERR(ctx);
 62	if (IS_ERR(ctx))
 63		goto out;
 64
 65	attr.ia_valid = ATTR_OPEN;
 66	if (openflags & O_TRUNC) {
 67		attr.ia_valid |= ATTR_SIZE;
 68		attr.ia_size = 0;
 69		filemap_write_and_wait(inode->i_mapping);
 70	}
 71
 72	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
 73	if (IS_ERR(inode)) {
 74		err = PTR_ERR(inode);
 75		switch (err) {
 76		default:
 77			goto out_put_ctx;
 78		case -ENOENT:
 79		case -ESTALE:
 80		case -EISDIR:
 81		case -ENOTDIR:
 82		case -ELOOP:
 83			goto out_drop;
 84		}
 85	}
 86	if (inode != d_inode(dentry))
 87		goto out_drop;
 88
 89	nfs_file_set_open_context(filp, ctx);
 90	nfs_fscache_open_file(inode, filp);
 91	err = 0;
 92	filp->f_mode |= FMODE_CAN_ODIRECT;
 93
 94out_put_ctx:
 95	put_nfs_open_context(ctx);
 96out:
 97	dput(parent);
 98	return err;
 99
100out_drop:
101	d_drop(dentry);
102	err = -EOPENSTALE;
103	goto out_put_ctx;
104}
105
106/*
107 * Flush all dirty pages, and check for write errors.
108 */
109static int
110nfs4_file_flush(struct file *file, fl_owner_t id)
111{
112	struct inode	*inode = file_inode(file);
113	errseq_t since;
114
115	dprintk("NFS: flush(%pD2)\n", file);
116
117	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
118	if ((file->f_mode & FMODE_WRITE) == 0)
119		return 0;
120
121	/*
122	 * If we're holding a write delegation, then check if we're required
123	 * to flush the i/o on close. If not, then just start the i/o now.
124	 */
125	if (!nfs4_delegation_flush_on_close(inode))
126		return filemap_fdatawrite(file->f_mapping);
127
128	/* Flush writes to the server and return any errors */
129	since = filemap_sample_wb_err(file->f_mapping);
130	nfs_wb_all(inode);
131	return filemap_check_wb_err(file->f_mapping, since);
132}
133
134#ifdef CONFIG_NFS_V4_2
135static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
136				      struct file *file_out, loff_t pos_out,
137				      size_t count, unsigned int flags)
138{
139	struct nfs42_copy_notify_res *cn_resp = NULL;
140	struct nl4_server *nss = NULL;
141	nfs4_stateid *cnrs = NULL;
142	ssize_t ret;
143	bool sync = false;
144
145	/* Only offload copy if superblock is the same */
146	if (file_in->f_op != &nfs4_file_operations)
147		return -EXDEV;
148	if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
149	    !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
150		return -EOPNOTSUPP;
151	if (file_inode(file_in) == file_inode(file_out))
152		return -EOPNOTSUPP;
153	/* if the copy size if smaller than 2 RPC payloads, make it
154	 * synchronous
155	 */
156	if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
157		sync = true;
158retry:
159	if (!nfs42_files_from_same_server(file_in, file_out)) {
160		/*
161		 * for inter copy, if copy size is too small
162		 * then fallback to generic copy.
 
163		 */
164		if (sync)
 
165			return -EOPNOTSUPP;
166		cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
167				  GFP_KERNEL);
168		if (unlikely(cn_resp == NULL))
169			return -ENOMEM;
170
171		ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
172		if (ret) {
173			ret = -EOPNOTSUPP;
174			goto out;
175		}
176		nss = &cn_resp->cnr_src;
177		cnrs = &cn_resp->cnr_stateid;
178	}
179	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
180				nss, cnrs, sync);
181out:
182	kfree(cn_resp);
183
184	if (ret == -EAGAIN)
185		goto retry;
186	return ret;
187}
188
189static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
190				    struct file *file_out, loff_t pos_out,
191				    size_t count, unsigned int flags)
192{
193	ssize_t ret;
194
195	ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
196				     flags);
197	if (ret == -EOPNOTSUPP || ret == -EXDEV)
198		ret = generic_copy_file_range(file_in, pos_in, file_out,
199					      pos_out, count, flags);
200	return ret;
201}
202
203static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
204{
205	loff_t ret;
206
207	switch (whence) {
208	case SEEK_HOLE:
209	case SEEK_DATA:
210		ret = nfs42_proc_llseek(filep, offset, whence);
211		if (ret != -EOPNOTSUPP)
212			return ret;
213		fallthrough;
214	default:
215		return nfs_file_llseek(filep, offset, whence);
216	}
217}
218
219static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
220{
221	struct inode *inode = file_inode(filep);
222	long ret;
223
224	if (!S_ISREG(inode->i_mode))
225		return -EOPNOTSUPP;
226
227	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
228		return -EOPNOTSUPP;
229
230	ret = inode_newsize_ok(inode, offset + len);
231	if (ret < 0)
232		return ret;
233
234	if (mode & FALLOC_FL_PUNCH_HOLE)
235		return nfs42_proc_deallocate(filep, offset, len);
236	return nfs42_proc_allocate(filep, offset, len);
237}
238
239static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
240		struct file *dst_file, loff_t dst_off, loff_t count,
241		unsigned int remap_flags)
242{
243	struct inode *dst_inode = file_inode(dst_file);
244	struct nfs_server *server = NFS_SERVER(dst_inode);
245	struct inode *src_inode = file_inode(src_file);
246	unsigned int bs = server->clone_blksize;
247	bool same_inode = false;
248	int ret;
249
250	/* NFS does not support deduplication. */
251	if (remap_flags & REMAP_FILE_DEDUP)
252		return -EOPNOTSUPP;
253
254	if (remap_flags & ~REMAP_FILE_ADVISORY)
255		return -EINVAL;
256
257	if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
258		return -ETXTBSY;
259
260	/* check alignment w.r.t. clone_blksize */
261	ret = -EINVAL;
262	if (bs) {
263		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
264			goto out;
265		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
266			goto out;
267	}
268
269	if (src_inode == dst_inode)
270		same_inode = true;
271
272	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
273	if (same_inode) {
274		inode_lock(src_inode);
275	} else if (dst_inode < src_inode) {
276		inode_lock_nested(dst_inode, I_MUTEX_PARENT);
277		inode_lock_nested(src_inode, I_MUTEX_CHILD);
278	} else {
279		inode_lock_nested(src_inode, I_MUTEX_PARENT);
280		inode_lock_nested(dst_inode, I_MUTEX_CHILD);
281	}
282
283	/* flush all pending writes on both src and dst so that server
284	 * has the latest data */
285	ret = nfs_sync_inode(src_inode);
286	if (ret)
287		goto out_unlock;
288	ret = nfs_sync_inode(dst_inode);
289	if (ret)
290		goto out_unlock;
291
292	ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
293
294	/* truncate inode page cache of the dst range so that future reads can fetch
295	 * new data from server */
296	if (!ret)
297		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
298
299out_unlock:
300	if (same_inode) {
301		inode_unlock(src_inode);
302	} else if (dst_inode < src_inode) {
303		inode_unlock(src_inode);
304		inode_unlock(dst_inode);
305	} else {
306		inode_unlock(dst_inode);
307		inode_unlock(src_inode);
308	}
309out:
310	return ret < 0 ? ret : count;
311}
312
313static int read_name_gen = 1;
314#define SSC_READ_NAME_BODY "ssc_read_%d"
315
316static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
317		struct nfs_fh *src_fh, nfs4_stateid *stateid)
318{
319	struct nfs_fattr *fattr = nfs_alloc_fattr();
320	struct file *filep, *res;
321	struct nfs_server *server;
322	struct inode *r_ino = NULL;
323	struct nfs_open_context *ctx;
324	struct nfs4_state_owner *sp;
325	char *read_name = NULL;
326	int len, status = 0;
327
328	server = NFS_SB(ss_mnt->mnt_sb);
329
330	if (!fattr)
331		return ERR_PTR(-ENOMEM);
332
333	status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
334	if (status < 0) {
335		res = ERR_PTR(status);
336		goto out;
337	}
338
339	if (!S_ISREG(fattr->mode)) {
340		res = ERR_PTR(-EBADF);
341		goto out;
342	}
343
344	res = ERR_PTR(-ENOMEM);
345	len = strlen(SSC_READ_NAME_BODY) + 16;
346	read_name = kzalloc(len, GFP_KERNEL);
347	if (read_name == NULL)
348		goto out;
349	snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
350
351	r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
 
352	if (IS_ERR(r_ino)) {
353		res = ERR_CAST(r_ino);
354		goto out_free_name;
355	}
356
357	filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
358				     r_ino->i_fop);
359	if (IS_ERR(filep)) {
360		res = ERR_CAST(filep);
361		iput(r_ino);
362		goto out_free_name;
363	}
 
364
365	ctx = alloc_nfs_open_context(filep->f_path.dentry,
366				     flags_to_mode(filep->f_flags), filep);
367	if (IS_ERR(ctx)) {
368		res = ERR_CAST(ctx);
369		goto out_filep;
370	}
371
372	res = ERR_PTR(-EINVAL);
373	sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
374	if (sp == NULL)
375		goto out_ctx;
376
377	ctx->state = nfs4_get_open_state(r_ino, sp);
378	if (ctx->state == NULL)
379		goto out_stateowner;
380
381	set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
382	memcpy(&ctx->state->open_stateid.other, &stateid->other,
383	       NFS4_STATEID_OTHER_SIZE);
384	update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
385	set_bit(NFS_OPEN_STATE, &ctx->state->flags);
386
387	nfs_file_set_open_context(filep, ctx);
388	put_nfs_open_context(ctx);
389
390	file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
391	res = filep;
392out_free_name:
393	kfree(read_name);
394out:
395	nfs_free_fattr(fattr);
396	return res;
397out_stateowner:
398	nfs4_put_state_owner(sp);
399out_ctx:
400	put_nfs_open_context(ctx);
401out_filep:
402	fput(filep);
403	goto out_free_name;
404}
405
406static void __nfs42_ssc_close(struct file *filep)
407{
408	struct nfs_open_context *ctx = nfs_file_open_context(filep);
409
410	ctx->state->flags = 0;
411}
412
413static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
414	.sco_open = __nfs42_ssc_open,
415	.sco_close = __nfs42_ssc_close,
416};
417
418/**
419 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
420 *
421 * Return values:
422 *   None
423 */
424void nfs42_ssc_register_ops(void)
425{
426	nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
427}
428
429/**
430 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
431 *
432 * Return values:
433 *   None.
434 */
435void nfs42_ssc_unregister_ops(void)
436{
437	nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
438}
439#endif /* CONFIG_NFS_V4_2 */
440
441static int nfs4_setlease(struct file *file, long arg, struct file_lock **lease,
442			 void **priv)
443{
444	return nfs4_proc_setlease(file, arg, lease, priv);
445}
446
447const struct file_operations nfs4_file_operations = {
448	.read_iter	= nfs_file_read,
449	.write_iter	= nfs_file_write,
450	.mmap		= nfs_file_mmap,
451	.open		= nfs4_file_open,
452	.flush		= nfs4_file_flush,
453	.release	= nfs_file_release,
454	.fsync		= nfs_file_fsync,
455	.lock		= nfs_lock,
456	.flock		= nfs_flock,
457	.splice_read	= generic_file_splice_read,
458	.splice_write	= iter_file_splice_write,
459	.check_flags	= nfs_check_flags,
460	.setlease	= nfs4_setlease,
461#ifdef CONFIG_NFS_V4_2
462	.copy_file_range = nfs4_copy_file_range,
463	.llseek		= nfs4_file_llseek,
464	.fallocate	= nfs42_fallocate,
465	.remap_file_range = nfs42_remap_file_range,
466#else
467	.llseek		= nfs_file_llseek,
468#endif
469};