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 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 /* We can't create new files here */
54 openflags &= ~(O_CREAT|O_EXCL);
55
56 parent = dget_parent(dentry);
57 dir = d_inode(parent);
58
59 ctx = alloc_nfs_open_context(file_dentry(filp),
60 flags_to_mode(openflags), filp);
61 err = PTR_ERR(ctx);
62 if (IS_ERR(ctx))
63 goto out;
64
65 attr.ia_valid = ATTR_OPEN;
66 if (openflags & O_TRUNC) {
67 attr.ia_valid |= ATTR_SIZE;
68 attr.ia_size = 0;
69 filemap_write_and_wait(inode->i_mapping);
70 }
71
72 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
73 if (IS_ERR(inode)) {
74 err = PTR_ERR(inode);
75 switch (err) {
76 default:
77 goto out_put_ctx;
78 case -ENOENT:
79 case -ESTALE:
80 case -EISDIR:
81 case -ENOTDIR:
82 case -ELOOP:
83 goto out_drop;
84 }
85 }
86 if (inode != d_inode(dentry))
87 goto out_drop;
88
89 nfs_file_set_open_context(filp, ctx);
90 nfs_fscache_open_file(inode, filp);
91 err = 0;
92 filp->f_mode |= FMODE_CAN_ODIRECT;
93
94 out_put_ctx:
95 put_nfs_open_context(ctx);
96 out:
97 dput(parent);
98 return err;
99
100 out_drop:
101 d_drop(dentry);
102 err = -EOPENSTALE;
103 goto out_put_ctx;
104 }
105
106 /*
107 * Flush all dirty pages, and check for write errors.
108 */
109 static int
nfs4_file_flush(struct file * file,fl_owner_t id)110 nfs4_file_flush(struct file *file, fl_owner_t id)
111 {
112 struct inode *inode = file_inode(file);
113 errseq_t since;
114
115 dprintk("NFS: flush(%pD2)\n", file);
116
117 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
118 if ((file->f_mode & FMODE_WRITE) == 0)
119 return 0;
120
121 /*
122 * If we're holding a write delegation, then check if we're required
123 * to flush the i/o on close. If not, then just start the i/o now.
124 */
125 if (!nfs4_delegation_flush_on_close(inode))
126 return filemap_fdatawrite(file->f_mapping);
127
128 /* Flush writes to the server and return any errors */
129 since = filemap_sample_wb_err(file->f_mapping);
130 nfs_wb_all(inode);
131 return filemap_check_wb_err(file->f_mapping, since);
132 }
133
134 #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)135 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
136 struct file *file_out, loff_t pos_out,
137 size_t count, unsigned int flags)
138 {
139 struct nfs42_copy_notify_res *cn_resp = NULL;
140 struct nl4_server *nss = NULL;
141 nfs4_stateid *cnrs = NULL;
142 ssize_t ret;
143 bool sync = false;
144
145 /* Only offload copy if superblock is the same */
146 if (file_in->f_op != &nfs4_file_operations)
147 return -EXDEV;
148 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
149 !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
150 return -EOPNOTSUPP;
151 if (file_inode(file_in) == file_inode(file_out))
152 return -EOPNOTSUPP;
153 /* if the copy size if smaller than 2 RPC payloads, make it
154 * synchronous
155 */
156 if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
157 sync = true;
158 retry:
159 if (!nfs42_files_from_same_server(file_in, file_out)) {
160 /*
161 * for inter copy, if copy size is too small
162 * then fallback to generic copy.
163 */
164 if (sync)
165 return -EOPNOTSUPP;
166 cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
167 GFP_KERNEL);
168 if (unlikely(cn_resp == NULL))
169 return -ENOMEM;
170
171 ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
172 if (ret) {
173 ret = -EOPNOTSUPP;
174 goto out;
175 }
176 nss = &cn_resp->cnr_src;
177 cnrs = &cn_resp->cnr_stateid;
178 }
179 ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
180 nss, cnrs, sync);
181 out:
182 kfree(cn_resp);
183
184 if (ret == -EAGAIN)
185 goto retry;
186 return ret;
187 }
188
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)189 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
190 struct file *file_out, loff_t pos_out,
191 size_t count, unsigned int flags)
192 {
193 ssize_t ret;
194
195 ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
196 flags);
197 if (ret == -EOPNOTSUPP || ret == -EXDEV)
198 ret = generic_copy_file_range(file_in, pos_in, file_out,
199 pos_out, count, flags);
200 return ret;
201 }
202
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)203 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
204 {
205 loff_t ret;
206
207 switch (whence) {
208 case SEEK_HOLE:
209 case SEEK_DATA:
210 ret = nfs42_proc_llseek(filep, offset, whence);
211 if (ret != -EOPNOTSUPP)
212 return ret;
213 fallthrough;
214 default:
215 return nfs_file_llseek(filep, offset, whence);
216 }
217 }
218
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)219 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
220 {
221 struct inode *inode = file_inode(filep);
222 long ret;
223
224 if (!S_ISREG(inode->i_mode))
225 return -EOPNOTSUPP;
226
227 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
228 return -EOPNOTSUPP;
229
230 ret = inode_newsize_ok(inode, offset + len);
231 if (ret < 0)
232 return ret;
233
234 if (mode & FALLOC_FL_PUNCH_HOLE)
235 return nfs42_proc_deallocate(filep, offset, len);
236 return nfs42_proc_allocate(filep, offset, len);
237 }
238
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)239 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
240 struct file *dst_file, loff_t dst_off, loff_t count,
241 unsigned int remap_flags)
242 {
243 struct inode *dst_inode = file_inode(dst_file);
244 struct nfs_server *server = NFS_SERVER(dst_inode);
245 struct inode *src_inode = file_inode(src_file);
246 unsigned int bs = server->clone_blksize;
247 bool same_inode = false;
248 int ret;
249
250 /* NFS does not support deduplication. */
251 if (remap_flags & REMAP_FILE_DEDUP)
252 return -EOPNOTSUPP;
253
254 if (remap_flags & ~REMAP_FILE_ADVISORY)
255 return -EINVAL;
256
257 if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
258 return -ETXTBSY;
259
260 /* check alignment w.r.t. clone_blksize */
261 ret = -EINVAL;
262 if (bs) {
263 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
264 goto out;
265 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
266 goto out;
267 }
268
269 if (src_inode == dst_inode)
270 same_inode = true;
271
272 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
273 if (same_inode) {
274 inode_lock(src_inode);
275 } else if (dst_inode < src_inode) {
276 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
277 inode_lock_nested(src_inode, I_MUTEX_CHILD);
278 } else {
279 inode_lock_nested(src_inode, I_MUTEX_PARENT);
280 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
281 }
282
283 /* flush all pending writes on both src and dst so that server
284 * has the latest data */
285 ret = nfs_sync_inode(src_inode);
286 if (ret)
287 goto out_unlock;
288 ret = nfs_sync_inode(dst_inode);
289 if (ret)
290 goto out_unlock;
291
292 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
293
294 /* truncate inode page cache of the dst range so that future reads can fetch
295 * new data from server */
296 if (!ret)
297 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
298
299 out_unlock:
300 if (same_inode) {
301 inode_unlock(src_inode);
302 } else if (dst_inode < src_inode) {
303 inode_unlock(src_inode);
304 inode_unlock(dst_inode);
305 } else {
306 inode_unlock(dst_inode);
307 inode_unlock(src_inode);
308 }
309 out:
310 return ret < 0 ? ret : count;
311 }
312
313 static int read_name_gen = 1;
314 #define SSC_READ_NAME_BODY "ssc_read_%d"
315
__nfs42_ssc_open(struct vfsmount * ss_mnt,struct nfs_fh * src_fh,nfs4_stateid * stateid)316 static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
317 struct nfs_fh *src_fh, nfs4_stateid *stateid)
318 {
319 struct nfs_fattr *fattr = nfs_alloc_fattr();
320 struct file *filep, *res;
321 struct nfs_server *server;
322 struct inode *r_ino = NULL;
323 struct nfs_open_context *ctx;
324 struct nfs4_state_owner *sp;
325 char *read_name = NULL;
326 int len, status = 0;
327
328 server = NFS_SB(ss_mnt->mnt_sb);
329
330 if (!fattr)
331 return ERR_PTR(-ENOMEM);
332
333 status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
334 if (status < 0) {
335 res = ERR_PTR(status);
336 goto out;
337 }
338
339 if (!S_ISREG(fattr->mode)) {
340 res = ERR_PTR(-EBADF);
341 goto out;
342 }
343
344 res = ERR_PTR(-ENOMEM);
345 len = strlen(SSC_READ_NAME_BODY) + 16;
346 read_name = kzalloc(len, GFP_KERNEL);
347 if (read_name == NULL)
348 goto out;
349 snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
350
351 r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
352 if (IS_ERR(r_ino)) {
353 res = ERR_CAST(r_ino);
354 goto out_free_name;
355 }
356
357 filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
358 r_ino->i_fop);
359 if (IS_ERR(filep)) {
360 res = ERR_CAST(filep);
361 iput(r_ino);
362 goto out_free_name;
363 }
364
365 ctx = alloc_nfs_open_context(filep->f_path.dentry,
366 flags_to_mode(filep->f_flags), filep);
367 if (IS_ERR(ctx)) {
368 res = ERR_CAST(ctx);
369 goto out_filep;
370 }
371
372 res = ERR_PTR(-EINVAL);
373 sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
374 if (sp == NULL)
375 goto out_ctx;
376
377 ctx->state = nfs4_get_open_state(r_ino, sp);
378 if (ctx->state == NULL)
379 goto out_stateowner;
380
381 set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
382 memcpy(&ctx->state->open_stateid.other, &stateid->other,
383 NFS4_STATEID_OTHER_SIZE);
384 update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
385 set_bit(NFS_OPEN_STATE, &ctx->state->flags);
386
387 nfs_file_set_open_context(filep, ctx);
388 put_nfs_open_context(ctx);
389
390 file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
391 res = filep;
392 out_free_name:
393 kfree(read_name);
394 out:
395 nfs_free_fattr(fattr);
396 return res;
397 out_stateowner:
398 nfs4_put_state_owner(sp);
399 out_ctx:
400 put_nfs_open_context(ctx);
401 out_filep:
402 fput(filep);
403 goto out_free_name;
404 }
405
__nfs42_ssc_close(struct file * filep)406 static void __nfs42_ssc_close(struct file *filep)
407 {
408 struct nfs_open_context *ctx = nfs_file_open_context(filep);
409
410 ctx->state->flags = 0;
411 }
412
413 static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
414 .sco_open = __nfs42_ssc_open,
415 .sco_close = __nfs42_ssc_close,
416 };
417
418 /**
419 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
420 *
421 * Return values:
422 * None
423 */
nfs42_ssc_register_ops(void)424 void nfs42_ssc_register_ops(void)
425 {
426 nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
427 }
428
429 /**
430 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
431 *
432 * Return values:
433 * None.
434 */
nfs42_ssc_unregister_ops(void)435 void nfs42_ssc_unregister_ops(void)
436 {
437 nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
438 }
439 #endif /* CONFIG_NFS_V4_2 */
440
nfs4_setlease(struct file * file,int arg,struct file_lock ** lease,void ** priv)441 static int nfs4_setlease(struct file *file, int arg, struct file_lock **lease,
442 void **priv)
443 {
444 return nfs4_proc_setlease(file, arg, lease, priv);
445 }
446
447 const struct file_operations nfs4_file_operations = {
448 .read_iter = nfs_file_read,
449 .write_iter = nfs_file_write,
450 .mmap = nfs_file_mmap,
451 .open = nfs4_file_open,
452 .flush = nfs4_file_flush,
453 .release = nfs_file_release,
454 .fsync = nfs_file_fsync,
455 .lock = nfs_lock,
456 .flock = nfs_flock,
457 .splice_read = nfs_file_splice_read,
458 .splice_write = iter_file_splice_write,
459 .check_flags = nfs_check_flags,
460 .setlease = nfs4_setlease,
461 #ifdef CONFIG_NFS_V4_2
462 .copy_file_range = nfs4_copy_file_range,
463 .llseek = nfs4_file_llseek,
464 .fallocate = nfs42_fallocate,
465 .remap_file_range = nfs42_remap_file_range,
466 #else
467 .llseek = nfs_file_llseek,
468 #endif
469 };
470