xref: /kernel/linux/linux-5.10/fs/nfs/nfs4file.c (revision 8c2ecf20) 
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	fmode_t f_mode;
36	struct iattr attr;
37	int err;
38
39	/*
40	 * If no cached dentry exists or if it's negative, NFSv4 handled the
41	 * opens in ->lookup() or ->create().
42	 *
43	 * We only get this far for a cached positive dentry.  We skipped
44	 * revalidation, so handle it here by dropping the dentry and returning
45	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
46	 */
47
48	dprintk("NFS: open file(%pd2)\n", dentry);
49
50	err = nfs_check_flags(openflags);
51	if (err)
52		return err;
53
54	f_mode = filp->f_mode;
55	if ((openflags & O_ACCMODE) == 3)
56		f_mode |= flags_to_mode(openflags);
57
58	/* We can't create new files here */
59	openflags &= ~(O_CREAT|O_EXCL);
60
61	parent = dget_parent(dentry);
62	dir = d_inode(parent);
63
64	ctx = alloc_nfs_open_context(file_dentry(filp), f_mode, filp);
65	err = PTR_ERR(ctx);
66	if (IS_ERR(ctx))
67		goto out;
68
69	attr.ia_valid = ATTR_OPEN;
70	if (openflags & O_TRUNC) {
71		attr.ia_valid |= ATTR_SIZE;
72		attr.ia_size = 0;
73		filemap_write_and_wait(inode->i_mapping);
74	}
75
76	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
77	if (IS_ERR(inode)) {
78		err = PTR_ERR(inode);
79		switch (err) {
80		default:
81			goto out_put_ctx;
82		case -ENOENT:
83		case -ESTALE:
84		case -EISDIR:
85		case -ENOTDIR:
86		case -ELOOP:
87			goto out_drop;
88		}
89	}
90	if (inode != d_inode(dentry))
91		goto out_drop;
92
93	nfs_file_set_open_context(filp, ctx);
94	nfs_fscache_open_file(inode, filp);
95	err = 0;
96
97out_put_ctx:
98	put_nfs_open_context(ctx);
99out:
100	dput(parent);
101	return err;
102
103out_drop:
104	d_drop(dentry);
105	err = -EOPENSTALE;
106	goto out_put_ctx;
107}
108
109/*
110 * Flush all dirty pages, and check for write errors.
111 */
112static int
113nfs4_file_flush(struct file *file, fl_owner_t id)
114{
115	struct inode	*inode = file_inode(file);
116	errseq_t since;
117
118	dprintk("NFS: flush(%pD2)\n", file);
119
120	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
121	if ((file->f_mode & FMODE_WRITE) == 0)
122		return 0;
123
124	/*
125	 * If we're holding a write delegation, then check if we're required
126	 * to flush the i/o on close. If not, then just start the i/o now.
127	 */
128	if (!nfs4_delegation_flush_on_close(inode))
129		return filemap_fdatawrite(file->f_mapping);
130
131	/* Flush writes to the server and return any errors */
132	since = filemap_sample_wb_err(file->f_mapping);
133	nfs_wb_all(inode);
134	return filemap_check_wb_err(file->f_mapping, since);
135}
136
137#ifdef CONFIG_NFS_V4_2
138static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
139				      struct file *file_out, loff_t pos_out,
140				      size_t count, unsigned int flags)
141{
142	struct nfs42_copy_notify_res *cn_resp = NULL;
143	struct nl4_server *nss = NULL;
144	nfs4_stateid *cnrs = NULL;
145	ssize_t ret;
146	bool sync = false;
147
148	/* Only offload copy if superblock is the same */
149	if (file_in->f_op != &nfs4_file_operations)
150		return -EXDEV;
151	if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
152	    !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
153		return -EOPNOTSUPP;
154	if (file_inode(file_in) == file_inode(file_out))
155		return -EOPNOTSUPP;
156	/* if the copy size if smaller than 2 RPC payloads, make it
157	 * synchronous
158	 */
159	if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
160		sync = true;
161retry:
162	if (!nfs42_files_from_same_server(file_in, file_out)) {
163		/* for inter copy, if copy size if smaller than 12 RPC
164		 * payloads, fallback to traditional copy. There are
165		 * 14 RPCs during an NFSv4.x mount between source/dest
166		 * servers.
167		 */
168		if (sync ||
169			count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
170			return -EOPNOTSUPP;
171		cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
172				GFP_NOFS);
173		if (unlikely(cn_resp == NULL))
174			return -ENOMEM;
175
176		ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
177		if (ret) {
178			ret = -EOPNOTSUPP;
179			goto out;
180		}
181		nss = &cn_resp->cnr_src;
182		cnrs = &cn_resp->cnr_stateid;
183	}
184	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
185				nss, cnrs, sync);
186out:
187	if (!nfs42_files_from_same_server(file_in, file_out))
188		kfree(cn_resp);
189	if (ret == -EAGAIN)
190		goto retry;
191	return ret;
192}
193
194static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
195				    struct file *file_out, loff_t pos_out,
196				    size_t count, unsigned int flags)
197{
198	ssize_t ret;
199
200	ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
201				     flags);
202	if (ret == -EOPNOTSUPP || ret == -EXDEV)
203		ret = generic_copy_file_range(file_in, pos_in, file_out,
204					      pos_out, count, flags);
205	return ret;
206}
207
208static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
209{
210	loff_t ret;
211
212	switch (whence) {
213	case SEEK_HOLE:
214	case SEEK_DATA:
215		ret = nfs42_proc_llseek(filep, offset, whence);
216		if (ret != -EOPNOTSUPP)
217			return ret;
218		fallthrough;
219	default:
220		return nfs_file_llseek(filep, offset, whence);
221	}
222}
223
224static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
225{
226	struct inode *inode = file_inode(filep);
227	long ret;
228
229	if (!S_ISREG(inode->i_mode))
230		return -EOPNOTSUPP;
231
232	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
233		return -EOPNOTSUPP;
234
235	ret = inode_newsize_ok(inode, offset + len);
236	if (ret < 0)
237		return ret;
238
239	if (mode & FALLOC_FL_PUNCH_HOLE)
240		return nfs42_proc_deallocate(filep, offset, len);
241	return nfs42_proc_allocate(filep, offset, len);
242}
243
244static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
245		struct file *dst_file, loff_t dst_off, loff_t count,
246		unsigned int remap_flags)
247{
248	struct inode *dst_inode = file_inode(dst_file);
249	struct nfs_server *server = NFS_SERVER(dst_inode);
250	struct inode *src_inode = file_inode(src_file);
251	unsigned int bs = server->clone_blksize;
252	bool same_inode = false;
253	int ret;
254
255	/* NFS does not support deduplication. */
256	if (remap_flags & REMAP_FILE_DEDUP)
257		return -EOPNOTSUPP;
258
259	if (remap_flags & ~REMAP_FILE_ADVISORY)
260		return -EINVAL;
261
262	if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
263		return -ETXTBSY;
264
265	/* check alignment w.r.t. clone_blksize */
266	ret = -EINVAL;
267	if (bs) {
268		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
269			goto out;
270		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
271			goto out;
272	}
273
274	if (src_inode == dst_inode)
275		same_inode = true;
276
277	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
278	if (same_inode) {
279		inode_lock(src_inode);
280	} else if (dst_inode < src_inode) {
281		inode_lock_nested(dst_inode, I_MUTEX_PARENT);
282		inode_lock_nested(src_inode, I_MUTEX_CHILD);
283	} else {
284		inode_lock_nested(src_inode, I_MUTEX_PARENT);
285		inode_lock_nested(dst_inode, I_MUTEX_CHILD);
286	}
287
288	/* flush all pending writes on both src and dst so that server
289	 * has the latest data */
290	ret = nfs_sync_inode(src_inode);
291	if (ret)
292		goto out_unlock;
293	ret = nfs_sync_inode(dst_inode);
294	if (ret)
295		goto out_unlock;
296
297	ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
298
299	/* truncate inode page cache of the dst range so that future reads can fetch
300	 * new data from server */
301	if (!ret)
302		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
303
304out_unlock:
305	if (same_inode) {
306		inode_unlock(src_inode);
307	} else if (dst_inode < src_inode) {
308		inode_unlock(src_inode);
309		inode_unlock(dst_inode);
310	} else {
311		inode_unlock(dst_inode);
312		inode_unlock(src_inode);
313	}
314out:
315	return ret < 0 ? ret : count;
316}
317
318static int read_name_gen = 1;
319#define SSC_READ_NAME_BODY "ssc_read_%d"
320
321static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
322		struct nfs_fh *src_fh, nfs4_stateid *stateid)
323{
324	struct nfs_fattr *fattr = nfs_alloc_fattr();
325	struct file *filep, *res;
326	struct nfs_server *server;
327	struct inode *r_ino = NULL;
328	struct nfs_open_context *ctx;
329	struct nfs4_state_owner *sp;
330	char *read_name = NULL;
331	int len, status = 0;
332
333	server = NFS_SERVER(ss_mnt->mnt_root->d_inode);
334
335	if (!fattr)
336		return ERR_PTR(-ENOMEM);
337
338	status = nfs4_proc_getattr(server, src_fh, fattr, NULL, NULL);
339	if (status < 0) {
340		res = ERR_PTR(status);
341		goto out;
342	}
343
344	if (!S_ISREG(fattr->mode)) {
345		res = ERR_PTR(-EBADF);
346		goto out;
347	}
348
349	res = ERR_PTR(-ENOMEM);
350	len = strlen(SSC_READ_NAME_BODY) + 16;
351	read_name = kzalloc(len, GFP_NOFS);
352	if (read_name == NULL)
353		goto out;
354	snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
355
356	r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, fattr,
357			NULL);
358	if (IS_ERR(r_ino)) {
359		res = ERR_CAST(r_ino);
360		goto out_free_name;
361	}
362
363	filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
364				     r_ino->i_fop);
365	if (IS_ERR(filep)) {
366		res = ERR_CAST(filep);
367		iput(r_ino);
368		goto out_free_name;
369	}
370	filep->f_mode |= FMODE_READ;
371
372	ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
373					filep);
374	if (IS_ERR(ctx)) {
375		res = ERR_CAST(ctx);
376		goto out_filep;
377	}
378
379	res = ERR_PTR(-EINVAL);
380	sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
381	if (sp == NULL)
382		goto out_ctx;
383
384	ctx->state = nfs4_get_open_state(r_ino, sp);
385	if (ctx->state == NULL)
386		goto out_stateowner;
387
388	set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
389	memcpy(&ctx->state->open_stateid.other, &stateid->other,
390	       NFS4_STATEID_OTHER_SIZE);
391	update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
392	set_bit(NFS_OPEN_STATE, &ctx->state->flags);
393
394	nfs_file_set_open_context(filep, ctx);
395	put_nfs_open_context(ctx);
396
397	file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
398	res = filep;
399out_free_name:
400	kfree(read_name);
401out:
402	nfs_free_fattr(fattr);
403	return res;
404out_stateowner:
405	nfs4_put_state_owner(sp);
406out_ctx:
407	put_nfs_open_context(ctx);
408out_filep:
409	fput(filep);
410	goto out_free_name;
411}
412
413static void __nfs42_ssc_close(struct file *filep)
414{
415	struct nfs_open_context *ctx = nfs_file_open_context(filep);
416
417	ctx->state->flags = 0;
418}
419
420static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
421	.sco_open = __nfs42_ssc_open,
422	.sco_close = __nfs42_ssc_close,
423};
424
425/**
426 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
427 *
428 * Return values:
429 *   None
430 */
431void nfs42_ssc_register_ops(void)
432{
433	nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
434}
435
436/**
437 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
438 *
439 * Return values:
440 *   None.
441 */
442void nfs42_ssc_unregister_ops(void)
443{
444	nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
445}
446#endif /* CONFIG_NFS_V4_2 */
447
448const struct file_operations nfs4_file_operations = {
449	.read_iter	= nfs_file_read,
450	.write_iter	= nfs_file_write,
451	.mmap		= nfs_file_mmap,
452	.open		= nfs4_file_open,
453	.flush		= nfs4_file_flush,
454	.release	= nfs_file_release,
455	.fsync		= nfs_file_fsync,
456	.lock		= nfs_lock,
457	.flock		= nfs_flock,
458	.splice_read	= generic_file_splice_read,
459	.splice_write	= iter_file_splice_write,
460	.check_flags	= nfs_check_flags,
461	.setlease	= simple_nosetlease,
462#ifdef CONFIG_NFS_V4_2
463	.copy_file_range = nfs4_copy_file_range,
464	.llseek		= nfs4_file_llseek,
465	.fallocate	= nfs42_fallocate,
466	.remap_file_range = nfs42_remap_file_range,
467#else
468	.llseek		= nfs_file_llseek,
469#endif
470};
471