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/nfs_fs.h>
11 #include "delegation.h"
12 #include "internal.h"
13 #include "iostat.h"
14 #include "fscache.h"
15 #include "pnfs.h"
16
17 #include "nfstrace.h"
18
19 #ifdef CONFIG_NFS_V4_2
20 #include "nfs42.h"
21 #endif
22
23 #define NFSDBG_FACILITY NFSDBG_FILE
24
25 static int
nfs4_file_open(struct inode * inode,struct file * filp)26 nfs4_file_open(struct inode *inode, struct file *filp)
27 {
28 struct nfs_open_context *ctx;
29 struct dentry *dentry = file_dentry(filp);
30 struct dentry *parent = NULL;
31 struct inode *dir;
32 unsigned openflags = filp->f_flags;
33 struct iattr attr;
34 int err;
35
36 /*
37 * If no cached dentry exists or if it's negative, NFSv4 handled the
38 * opens in ->lookup() or ->create().
39 *
40 * We only get this far for a cached positive dentry. We skipped
41 * revalidation, so handle it here by dropping the dentry and returning
42 * -EOPENSTALE. The VFS will retry the lookup/create/open.
43 */
44
45 dprintk("NFS: open file(%pd2)\n", dentry);
46
47 err = nfs_check_flags(openflags);
48 if (err)
49 return err;
50
51 if ((openflags & O_ACCMODE) == 3)
52 return nfs_open(inode, filp);
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), filp->f_mode, 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
93 out_put_ctx:
94 put_nfs_open_context(ctx);
95 out:
96 dput(parent);
97 return err;
98
99 out_drop:
100 d_drop(dentry);
101 err = -EOPENSTALE;
102 goto out_put_ctx;
103 }
104
105 /*
106 * Flush all dirty pages, and check for write errors.
107 */
108 static int
nfs4_file_flush(struct file * file,fl_owner_t id)109 nfs4_file_flush(struct file *file, fl_owner_t id)
110 {
111 struct inode *inode = file_inode(file);
112 errseq_t since;
113
114 dprintk("NFS: flush(%pD2)\n", file);
115
116 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
117 if ((file->f_mode & FMODE_WRITE) == 0)
118 return 0;
119
120 /*
121 * If we're holding a write delegation, then check if we're required
122 * to flush the i/o on close. If not, then just start the i/o now.
123 */
124 if (!nfs4_delegation_flush_on_close(inode))
125 return filemap_fdatawrite(file->f_mapping);
126
127 /* Flush writes to the server and return any errors */
128 since = filemap_sample_wb_err(file->f_mapping);
129 nfs_wb_all(inode);
130 return filemap_check_wb_err(file->f_mapping, since);
131 }
132
133 #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)134 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
135 struct file *file_out, loff_t pos_out,
136 size_t count, unsigned int flags)
137 {
138 /* Only offload copy if superblock is the same */
139 if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
140 return -EXDEV;
141 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
142 !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
143 return -EOPNOTSUPP;
144 if (file_inode(file_in) == file_inode(file_out))
145 return -EOPNOTSUPP;
146 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
147 }
148
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)149 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
150 struct file *file_out, loff_t pos_out,
151 size_t count, unsigned int flags)
152 {
153 ssize_t ret;
154
155 ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
156 flags);
157 if (ret == -EOPNOTSUPP || ret == -EXDEV)
158 ret = generic_copy_file_range(file_in, pos_in, file_out,
159 pos_out, count, flags);
160 return ret;
161 }
162
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)163 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
164 {
165 loff_t ret;
166
167 switch (whence) {
168 case SEEK_HOLE:
169 case SEEK_DATA:
170 ret = nfs42_proc_llseek(filep, offset, whence);
171 if (ret != -EOPNOTSUPP)
172 return ret;
173 /* Fall through */
174 default:
175 return nfs_file_llseek(filep, offset, whence);
176 }
177 }
178
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)179 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
180 {
181 struct inode *inode = file_inode(filep);
182 long ret;
183
184 if (!S_ISREG(inode->i_mode))
185 return -EOPNOTSUPP;
186
187 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
188 return -EOPNOTSUPP;
189
190 ret = inode_newsize_ok(inode, offset + len);
191 if (ret < 0)
192 return ret;
193
194 if (mode & FALLOC_FL_PUNCH_HOLE)
195 return nfs42_proc_deallocate(filep, offset, len);
196 return nfs42_proc_allocate(filep, offset, len);
197 }
198
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)199 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
200 struct file *dst_file, loff_t dst_off, loff_t count,
201 unsigned int remap_flags)
202 {
203 struct inode *dst_inode = file_inode(dst_file);
204 struct nfs_server *server = NFS_SERVER(dst_inode);
205 struct inode *src_inode = file_inode(src_file);
206 unsigned int bs = server->clone_blksize;
207 bool same_inode = false;
208 int ret;
209
210 /* NFS does not support deduplication. */
211 if (remap_flags & REMAP_FILE_DEDUP)
212 return -EOPNOTSUPP;
213
214 if (remap_flags & ~REMAP_FILE_ADVISORY)
215 return -EINVAL;
216
217 if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
218 return -ETXTBSY;
219
220 /* check alignment w.r.t. clone_blksize */
221 ret = -EINVAL;
222 if (bs) {
223 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
224 goto out;
225 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
226 goto out;
227 }
228
229 if (src_inode == dst_inode)
230 same_inode = true;
231
232 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
233 if (same_inode) {
234 inode_lock(src_inode);
235 } else if (dst_inode < src_inode) {
236 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
237 inode_lock_nested(src_inode, I_MUTEX_CHILD);
238 } else {
239 inode_lock_nested(src_inode, I_MUTEX_PARENT);
240 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
241 }
242
243 /* flush all pending writes on both src and dst so that server
244 * has the latest data */
245 ret = nfs_sync_inode(src_inode);
246 if (ret)
247 goto out_unlock;
248 ret = nfs_sync_inode(dst_inode);
249 if (ret)
250 goto out_unlock;
251
252 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
253
254 /* truncate inode page cache of the dst range so that future reads can fetch
255 * new data from server */
256 if (!ret)
257 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
258
259 out_unlock:
260 if (same_inode) {
261 inode_unlock(src_inode);
262 } else if (dst_inode < src_inode) {
263 inode_unlock(src_inode);
264 inode_unlock(dst_inode);
265 } else {
266 inode_unlock(dst_inode);
267 inode_unlock(src_inode);
268 }
269 out:
270 return ret < 0 ? ret : count;
271 }
272 #endif /* CONFIG_NFS_V4_2 */
273
274 const struct file_operations nfs4_file_operations = {
275 .read_iter = nfs_file_read,
276 .write_iter = nfs_file_write,
277 .mmap = nfs_file_mmap,
278 .open = nfs4_file_open,
279 .flush = nfs4_file_flush,
280 .release = nfs_file_release,
281 .fsync = nfs_file_fsync,
282 .lock = nfs_lock,
283 .flock = nfs_flock,
284 .splice_read = generic_file_splice_read,
285 .splice_write = iter_file_splice_write,
286 .check_flags = nfs_check_flags,
287 .setlease = simple_nosetlease,
288 #ifdef CONFIG_NFS_V4_2
289 .copy_file_range = nfs4_copy_file_range,
290 .llseek = nfs4_file_llseek,
291 .fallocate = nfs42_fallocate,
292 .remap_file_range = nfs42_remap_file_range,
293 #else
294 .llseek = nfs_file_llseek,
295 #endif
296 };
297