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 <linux/splice.h>
14#include "delegation.h"
15#include "internal.h"
16#include "iostat.h"
17#include "fscache.h"
18#include "pnfs.h"
19
20#include "nfstrace.h"
21
22#ifdef CONFIG_NFS_V4_2
23#include "nfs42.h"
24#endif
25
26#define NFSDBG_FACILITY NFSDBG_FILE
27
28static int
29nfs4_file_open(struct inode *inode, struct file *filp)
30{
31 struct nfs_open_context *ctx;
32 struct dentry *dentry = file_dentry(file: filp);
33 struct dentry *parent = NULL;
34 struct inode *dir;
35 unsigned openflags = filp->f_flags;
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 /* We can't create new files here */
55 openflags &= ~(O_CREAT|O_EXCL);
56
57 parent = dget_parent(dentry);
58 dir = d_inode(dentry: parent);
59
60 ctx = alloc_nfs_open_context(dentry: file_dentry(file: filp),
61 f_mode: flags_to_mode(flags: openflags), filp);
62 err = PTR_ERR(ptr: ctx);
63 if (IS_ERR(ptr: ctx))
64 goto out;
65
66 attr.ia_valid = ATTR_OPEN;
67 if (openflags & O_TRUNC) {
68 attr.ia_valid |= ATTR_SIZE;
69 attr.ia_size = 0;
70 filemap_write_and_wait(mapping: inode->i_mapping);
71 }
72
73 inode = NFS_PROTO(inode: dir)->open_context(dir, ctx, openflags, &attr, NULL);
74 if (IS_ERR(ptr: inode)) {
75 err = PTR_ERR(ptr: inode);
76 switch (err) {
77 default:
78 goto out_put_ctx;
79 case -ENOENT:
80 case -ESTALE:
81 case -EISDIR:
82 case -ENOTDIR:
83 case -ELOOP:
84 goto out_drop;
85 }
86 }
87 if (inode != d_inode(dentry))
88 goto out_drop;
89
90 nfs_file_set_open_context(filp, ctx);
91 nfs_fscache_open_file(inode, filp);
92 err = 0;
93 filp->f_mode |= FMODE_CAN_ODIRECT;
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(f: file);
114 errseq_t since;
115
116 dprintk("NFS: flush(%pD2)\n", file);
117
118 nfs_inc_stats(inode, stat: 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(mapping: file->f_mapping);
131 nfs_wb_all(inode);
132 return filemap_check_wb_err(mapping: 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 /*
162 * for inter copy, if copy size is too small
163 * then fallback to generic copy.
164 */
165 if (sync)
166 return -EOPNOTSUPP;
167 cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
168 GFP_KERNEL);
169 if (unlikely(cn_resp == NULL))
170 return -ENOMEM;
171
172 ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
173 if (ret) {
174 ret = -EOPNOTSUPP;
175 goto out;
176 }
177 nss = &cn_resp->cnr_src;
178 cnrs = &cn_resp->cnr_stateid;
179 }
180 ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
181 nss, cnrs, sync);
182out:
183 kfree(cn_resp);
184
185 if (ret == -EAGAIN)
186 goto retry;
187 return ret;
188}
189
190static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
191 struct file *file_out, loff_t pos_out,
192 size_t count, unsigned int flags)
193{
194 ssize_t ret;
195
196 ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
197 flags);
198 if (ret == -EOPNOTSUPP || ret == -EXDEV)
199 ret = splice_copy_file_range(file_in, pos_in, file_out,
200 pos_out, count);
201 return ret;
202}
203
204static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
205{
206 loff_t ret;
207
208 switch (whence) {
209 case SEEK_HOLE:
210 case SEEK_DATA:
211 ret = nfs42_proc_llseek(filep, offset, whence);
212 if (ret != -EOPNOTSUPP)
213 return ret;
214 fallthrough;
215 default:
216 return nfs_file_llseek(filep, offset, whence);
217 }
218}
219
220static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
221{
222 struct inode *inode = file_inode(filep);
223 long ret;
224
225 if (!S_ISREG(inode->i_mode))
226 return -EOPNOTSUPP;
227
228 switch (mode) {
229 case 0:
230 case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
231 case FALLOC_FL_ZERO_RANGE:
232 break;
233 default:
234 return -EOPNOTSUPP;
235 }
236
237 ret = inode_newsize_ok(inode, offset + len);
238 if (ret < 0)
239 return ret;
240
241 if (mode & FALLOC_FL_PUNCH_HOLE)
242 return nfs42_proc_deallocate(filep, offset, len);
243 else if (mode & FALLOC_FL_ZERO_RANGE)
244 return nfs42_proc_zero_range(filep, offset ,len);
245 return nfs42_proc_allocate(filep, offset, len);
246}
247
248static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
249 struct file *dst_file, loff_t dst_off, loff_t count,
250 unsigned int remap_flags)
251{
252 struct inode *dst_inode = file_inode(dst_file);
253 struct nfs_server *server = NFS_SERVER(dst_inode);
254 struct inode *src_inode = file_inode(src_file);
255 unsigned int bs = server->clone_blksize;
256 int ret;
257
258 /* NFS does not support deduplication. */
259 if (remap_flags & REMAP_FILE_DEDUP)
260 return -EOPNOTSUPP;
261
262 if (remap_flags & ~REMAP_FILE_ADVISORY)
263 return -EINVAL;
264
265 if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
266 return -ETXTBSY;
267
268 /* check alignment w.r.t. clone_blksize */
269 ret = -EINVAL;
270 if (bs) {
271 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
272 goto out;
273 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
274 goto out;
275 }
276
277 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
278 lock_two_nondirectories(src_inode, dst_inode);
279 /* flush all pending writes on both src and dst so that server
280 * has the latest data */
281 nfs_file_block_o_direct(NFS_I(src_inode));
282 ret = nfs_sync_inode(src_inode);
283 if (ret)
284 goto out_unlock;
285 nfs_file_block_o_direct(NFS_I(dst_inode));
286 ret = nfs_sync_inode(dst_inode);
287 if (ret)
288 goto out_unlock;
289
290 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
291
292 /* truncate inode page cache of the dst range so that future reads can fetch
293 * new data from server */
294 if (!ret)
295 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
296
297out_unlock:
298 unlock_two_nondirectories(src_inode, dst_inode);
299out:
300 return ret < 0 ? ret : count;
301}
302
303static int read_name_gen = 1;
304#define SSC_READ_NAME_BODY "ssc_read_%d"
305
306static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
307 struct nfs_fh *src_fh, nfs4_stateid *stateid)
308{
309 struct nfs_fattr *fattr = nfs_alloc_fattr();
310 struct file *filep, *res;
311 struct nfs_server *server;
312 struct inode *r_ino = NULL;
313 struct nfs_open_context *ctx;
314 struct nfs4_state_owner *sp;
315 char *read_name = NULL;
316 int len, status = 0;
317
318 server = NFS_SB(ss_mnt->mnt_sb);
319
320 if (!fattr)
321 return ERR_PTR(-ENOMEM);
322
323 status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
324 if (status < 0) {
325 res = ERR_PTR(status);
326 goto out;
327 }
328
329 if (!S_ISREG(fattr->mode)) {
330 res = ERR_PTR(-EBADF);
331 goto out;
332 }
333
334 res = ERR_PTR(-ENOMEM);
335 len = strlen(SSC_READ_NAME_BODY) + 16;
336 read_name = kzalloc(len, GFP_KERNEL);
337 if (read_name == NULL)
338 goto out;
339 snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
340
341 r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
342 if (IS_ERR(r_ino)) {
343 res = ERR_CAST(r_ino);
344 goto out_free_name;
345 }
346
347 filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
348 r_ino->i_fop);
349 if (IS_ERR(filep)) {
350 res = ERR_CAST(filep);
351 iput(r_ino);
352 goto out_free_name;
353 }
354
355 ctx = alloc_nfs_open_context(filep->f_path.dentry,
356 flags_to_mode(filep->f_flags), filep);
357 if (IS_ERR(ctx)) {
358 res = ERR_CAST(ctx);
359 goto out_filep;
360 }
361
362 res = ERR_PTR(-EINVAL);
363 sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
364 if (sp == NULL)
365 goto out_ctx;
366
367 ctx->state = nfs4_get_open_state(r_ino, sp);
368 if (ctx->state == NULL)
369 goto out_stateowner;
370
371 set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
372 memcpy(&ctx->state->open_stateid.other, &stateid->other,
373 NFS4_STATEID_OTHER_SIZE);
374 update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
375 set_bit(NFS_OPEN_STATE, &ctx->state->flags);
376
377 nfs_file_set_open_context(filep, ctx);
378 put_nfs_open_context(ctx);
379
380 file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
381 res = filep;
382out_free_name:
383 kfree(read_name);
384out:
385 nfs_free_fattr(fattr);
386 return res;
387out_stateowner:
388 nfs4_put_state_owner(sp);
389out_ctx:
390 put_nfs_open_context(ctx);
391out_filep:
392 fput(filep);
393 goto out_free_name;
394}
395
396static void __nfs42_ssc_close(struct file *filep)
397{
398 struct nfs_open_context *ctx = nfs_file_open_context(filep);
399
400 ctx->state->flags = 0;
401}
402
403static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
404 .sco_open = __nfs42_ssc_open,
405 .sco_close = __nfs42_ssc_close,
406};
407
408/**
409 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
410 *
411 * Return values:
412 * None
413 */
414void nfs42_ssc_register_ops(void)
415{
416 nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
417}
418
419/**
420 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
421 *
422 * Return values:
423 * None.
424 */
425void nfs42_ssc_unregister_ops(void)
426{
427 nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
428}
429#endif /* CONFIG_NFS_V4_2 */
430
431static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease,
432 void **priv)
433{
434 return nfs4_proc_setlease(file, arg, lease, priv);
435}
436
437const struct file_operations nfs4_file_operations = {
438 .read_iter = nfs_file_read,
439 .write_iter = nfs_file_write,
440 .mmap_prepare = nfs_file_mmap_prepare,
441 .open = nfs4_file_open,
442 .flush = nfs4_file_flush,
443 .release = nfs_file_release,
444 .fsync = nfs_file_fsync,
445 .lock = nfs_lock,
446 .flock = nfs_flock,
447 .splice_read = nfs_file_splice_read,
448 .splice_write = iter_file_splice_write,
449 .check_flags = nfs_check_flags,
450 .setlease = nfs4_setlease,
451#ifdef CONFIG_NFS_V4_2
452 .copy_file_range = nfs4_copy_file_range,
453 .llseek = nfs4_file_llseek,
454 .fallocate = nfs42_fallocate,
455 .remap_file_range = nfs42_remap_file_range,
456#else
457 .llseek = nfs_file_llseek,
458#endif
459 .fop_flags = FOP_DONTCACHE,
460};
461