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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};