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
28 static int
nfs4_file_open(struct inode * inode,struct file * filp)29 nfs4_file_open(struct inode *inode, struct file *filp)
30 {
31 struct nfs_open_context *ctx;
32 struct dentry *dentry = file_dentry(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(parent);
59
60 ctx = alloc_nfs_open_context(file_dentry(filp),
61 flags_to_mode(openflags), filp);
62 err = PTR_ERR(ctx);
63 if (IS_ERR(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(inode->i_mapping);
71 }
72
73 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
74 if (IS_ERR(inode)) {
75 err = PTR_ERR(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
95 out_put_ctx:
96 put_nfs_open_context(ctx);
97 out:
98 dput(parent);
99 return err;
100
101 out_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 */
110 static int
nfs4_file_flush(struct file * file,fl_owner_t id)111 nfs4_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
__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)136 static 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;
159 retry:
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);
182 out:
183 kfree(cn_resp);
184
185 if (ret == -EAGAIN)
186 goto retry;
187 return ret;
188 }
189
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)190 static 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
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)204 static 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
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)220 static 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 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
229 return -EOPNOTSUPP;
230
231 ret = inode_newsize_ok(inode, offset + len);
232 if (ret < 0)
233 return ret;
234
235 if (mode & FALLOC_FL_PUNCH_HOLE)
236 return nfs42_proc_deallocate(filep, offset, len);
237 return nfs42_proc_allocate(filep, offset, len);
238 }
239
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)240 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
241 struct file *dst_file, loff_t dst_off, loff_t count,
242 unsigned int remap_flags)
243 {
244 struct inode *dst_inode = file_inode(dst_file);
245 struct nfs_server *server = NFS_SERVER(dst_inode);
246 struct inode *src_inode = file_inode(src_file);
247 unsigned int bs = server->clone_blksize;
248 bool same_inode = false;
249 int ret;
250
251 /* NFS does not support deduplication. */
252 if (remap_flags & REMAP_FILE_DEDUP)
253 return -EOPNOTSUPP;
254
255 if (remap_flags & ~REMAP_FILE_ADVISORY)
256 return -EINVAL;
257
258 if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
259 return -ETXTBSY;
260
261 /* check alignment w.r.t. clone_blksize */
262 ret = -EINVAL;
263 if (bs) {
264 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
265 goto out;
266 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
267 goto out;
268 }
269
270 if (src_inode == dst_inode)
271 same_inode = true;
272
273 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
274 if (same_inode) {
275 inode_lock(src_inode);
276 } else if (dst_inode < src_inode) {
277 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
278 inode_lock_nested(src_inode, I_MUTEX_CHILD);
279 } else {
280 inode_lock_nested(src_inode, I_MUTEX_PARENT);
281 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
282 }
283
284 /* flush all pending writes on both src and dst so that server
285 * has the latest data */
286 ret = nfs_sync_inode(src_inode);
287 if (ret)
288 goto out_unlock;
289 ret = nfs_sync_inode(dst_inode);
290 if (ret)
291 goto out_unlock;
292
293 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
294
295 /* truncate inode page cache of the dst range so that future reads can fetch
296 * new data from server */
297 if (!ret)
298 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
299
300 out_unlock:
301 if (same_inode) {
302 inode_unlock(src_inode);
303 } else if (dst_inode < src_inode) {
304 inode_unlock(src_inode);
305 inode_unlock(dst_inode);
306 } else {
307 inode_unlock(dst_inode);
308 inode_unlock(src_inode);
309 }
310 out:
311 return ret < 0 ? ret : count;
312 }
313
314 static int read_name_gen = 1;
315 #define SSC_READ_NAME_BODY "ssc_read_%d"
316
__nfs42_ssc_open(struct vfsmount * ss_mnt,struct nfs_fh * src_fh,nfs4_stateid * stateid)317 static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
318 struct nfs_fh *src_fh, nfs4_stateid *stateid)
319 {
320 struct nfs_fattr *fattr = nfs_alloc_fattr();
321 struct file *filep, *res;
322 struct nfs_server *server;
323 struct inode *r_ino = NULL;
324 struct nfs_open_context *ctx;
325 struct nfs4_state_owner *sp;
326 char *read_name = NULL;
327 int len, status = 0;
328
329 server = NFS_SB(ss_mnt->mnt_sb);
330
331 if (!fattr)
332 return ERR_PTR(-ENOMEM);
333
334 status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
335 if (status < 0) {
336 res = ERR_PTR(status);
337 goto out;
338 }
339
340 if (!S_ISREG(fattr->mode)) {
341 res = ERR_PTR(-EBADF);
342 goto out;
343 }
344
345 res = ERR_PTR(-ENOMEM);
346 len = strlen(SSC_READ_NAME_BODY) + 16;
347 read_name = kzalloc(len, GFP_KERNEL);
348 if (read_name == NULL)
349 goto out;
350 snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
351
352 r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
353 if (IS_ERR(r_ino)) {
354 res = ERR_CAST(r_ino);
355 goto out_free_name;
356 }
357
358 filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
359 r_ino->i_fop);
360 if (IS_ERR(filep)) {
361 res = ERR_CAST(filep);
362 iput(r_ino);
363 goto out_free_name;
364 }
365
366 ctx = alloc_nfs_open_context(filep->f_path.dentry,
367 flags_to_mode(filep->f_flags), filep);
368 if (IS_ERR(ctx)) {
369 res = ERR_CAST(ctx);
370 goto out_filep;
371 }
372
373 res = ERR_PTR(-EINVAL);
374 sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
375 if (sp == NULL)
376 goto out_ctx;
377
378 ctx->state = nfs4_get_open_state(r_ino, sp);
379 if (ctx->state == NULL)
380 goto out_stateowner;
381
382 set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
383 memcpy(&ctx->state->open_stateid.other, &stateid->other,
384 NFS4_STATEID_OTHER_SIZE);
385 update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
386 set_bit(NFS_OPEN_STATE, &ctx->state->flags);
387
388 nfs_file_set_open_context(filep, ctx);
389 put_nfs_open_context(ctx);
390
391 file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
392 res = filep;
393 out_free_name:
394 kfree(read_name);
395 out:
396 nfs_free_fattr(fattr);
397 return res;
398 out_stateowner:
399 nfs4_put_state_owner(sp);
400 out_ctx:
401 put_nfs_open_context(ctx);
402 out_filep:
403 fput(filep);
404 goto out_free_name;
405 }
406
__nfs42_ssc_close(struct file * filep)407 static void __nfs42_ssc_close(struct file *filep)
408 {
409 struct nfs_open_context *ctx = nfs_file_open_context(filep);
410
411 ctx->state->flags = 0;
412 }
413
414 static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
415 .sco_open = __nfs42_ssc_open,
416 .sco_close = __nfs42_ssc_close,
417 };
418
419 /**
420 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
421 *
422 * Return values:
423 * None
424 */
nfs42_ssc_register_ops(void)425 void nfs42_ssc_register_ops(void)
426 {
427 nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
428 }
429
430 /**
431 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
432 *
433 * Return values:
434 * None.
435 */
nfs42_ssc_unregister_ops(void)436 void nfs42_ssc_unregister_ops(void)
437 {
438 nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
439 }
440 #endif /* CONFIG_NFS_V4_2 */
441
nfs4_setlease(struct file * file,int arg,struct file_lease ** lease,void ** priv)442 static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease,
443 void **priv)
444 {
445 return nfs4_proc_setlease(file, arg, lease, priv);
446 }
447
448 const 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 = nfs_file_splice_read,
459 .splice_write = iter_file_splice_write,
460 .check_flags = nfs_check_flags,
461 .setlease = nfs4_setlease,
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