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
27 static int
nfs4_file_open(struct inode * inode,struct file * filp)28 nfs4_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
97 out_put_ctx:
98 put_nfs_open_context(ctx);
99 out:
100 dput(parent);
101 return err;
102
103 out_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 */
112 static int
nfs4_file_flush(struct file * file,fl_owner_t id)113 nfs4_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
__nfs4_copy_file_range(struct file * file_in,loff_t pos_in,struct file * file_out,loff_t pos_out,size_t count,unsigned int flags)138 static 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;
161 retry:
162 if (!nfs42_files_from_same_server(file_in, file_out)) {
163 /*
164 * for inter copy, if copy size is too small
165 * then fallback to generic copy.
166 */
167 if (sync)
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);
184 out:
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
nfs4_copy_file_range(struct file * file_in,loff_t pos_in,struct file * file_out,loff_t pos_out,size_t count,unsigned int flags)192 static 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
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)206 static 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
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)222 static 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
nfs42_remap_file_range(struct file * src_file,loff_t src_off,struct file * dst_file,loff_t dst_off,loff_t count,unsigned int remap_flags)242 static 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
302 out_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 }
312 out:
313 return ret < 0 ? ret : count;
314 }
315
316 static int read_name_gen = 1;
317 #define SSC_READ_NAME_BODY "ssc_read_%d"
318
__nfs42_ssc_open(struct vfsmount * ss_mnt,struct nfs_fh * src_fh,nfs4_stateid * stateid)319 static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
320 struct nfs_fh *src_fh, nfs4_stateid *stateid)
321 {
322 struct nfs_fattr *fattr = nfs_alloc_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 if (!fattr)
334 return ERR_PTR(-ENOMEM);
335
336 status = nfs4_proc_getattr(server, src_fh, fattr, NULL, NULL);
337 if (status < 0) {
338 res = ERR_PTR(status);
339 goto out;
340 }
341
342 if (!S_ISREG(fattr->mode)) {
343 res = ERR_PTR(-EBADF);
344 goto out;
345 }
346
347 res = ERR_PTR(-ENOMEM);
348 len = strlen(SSC_READ_NAME_BODY) + 16;
349 read_name = kzalloc(len, GFP_NOFS);
350 if (read_name == NULL)
351 goto out;
352 snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
353
354 r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, fattr,
355 NULL);
356 if (IS_ERR(r_ino)) {
357 res = ERR_CAST(r_ino);
358 goto out_free_name;
359 }
360
361 filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
362 r_ino->i_fop);
363 if (IS_ERR(filep)) {
364 res = ERR_CAST(filep);
365 iput(r_ino);
366 goto out_free_name;
367 }
368 filep->f_mode |= FMODE_READ;
369
370 ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
371 filep);
372 if (IS_ERR(ctx)) {
373 res = ERR_CAST(ctx);
374 goto out_filep;
375 }
376
377 res = ERR_PTR(-EINVAL);
378 sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
379 if (sp == NULL)
380 goto out_ctx;
381
382 ctx->state = nfs4_get_open_state(r_ino, sp);
383 if (ctx->state == NULL)
384 goto out_stateowner;
385
386 set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
387 memcpy(&ctx->state->open_stateid.other, &stateid->other,
388 NFS4_STATEID_OTHER_SIZE);
389 update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
390 set_bit(NFS_OPEN_STATE, &ctx->state->flags);
391
392 nfs_file_set_open_context(filep, ctx);
393 put_nfs_open_context(ctx);
394
395 file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
396 res = filep;
397 out_free_name:
398 kfree(read_name);
399 out:
400 nfs_free_fattr(fattr);
401 return res;
402 out_stateowner:
403 nfs4_put_state_owner(sp);
404 out_ctx:
405 put_nfs_open_context(ctx);
406 out_filep:
407 fput(filep);
408 goto out_free_name;
409 }
410
__nfs42_ssc_close(struct file * filep)411 static void __nfs42_ssc_close(struct file *filep)
412 {
413 struct nfs_open_context *ctx = nfs_file_open_context(filep);
414
415 ctx->state->flags = 0;
416 }
417
418 static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
419 .sco_open = __nfs42_ssc_open,
420 .sco_close = __nfs42_ssc_close,
421 };
422
423 /**
424 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
425 *
426 * Return values:
427 * None
428 */
nfs42_ssc_register_ops(void)429 void nfs42_ssc_register_ops(void)
430 {
431 nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
432 }
433
434 /**
435 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
436 *
437 * Return values:
438 * None.
439 */
nfs42_ssc_unregister_ops(void)440 void nfs42_ssc_unregister_ops(void)
441 {
442 nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
443 }
444 #endif /* CONFIG_NFS_V4_2 */
445
nfs4_setlease(struct file * file,long arg,struct file_lock ** lease,void ** priv)446 static int nfs4_setlease(struct file *file, long arg, struct file_lock **lease,
447 void **priv)
448 {
449 return nfs4_proc_setlease(file, arg, lease, priv);
450 }
451
452 const struct file_operations nfs4_file_operations = {
453 .read_iter = nfs_file_read,
454 .write_iter = nfs_file_write,
455 .mmap = nfs_file_mmap,
456 .open = nfs4_file_open,
457 .flush = nfs4_file_flush,
458 .release = nfs_file_release,
459 .fsync = nfs_file_fsync,
460 .lock = nfs_lock,
461 .flock = nfs_flock,
462 .splice_read = generic_file_splice_read,
463 .splice_write = iter_file_splice_write,
464 .check_flags = nfs_check_flags,
465 .setlease = nfs4_setlease,
466 #ifdef CONFIG_NFS_V4_2
467 .copy_file_range = nfs4_copy_file_range,
468 .llseek = nfs4_file_llseek,
469 .fallocate = nfs42_fallocate,
470 .remap_file_range = nfs42_remap_file_range,
471 #else
472 .llseek = nfs_file_llseek,
473 #endif
474 };
475