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_set_verifier(dentry, nfs_save_change_attribute(dir));
90 nfs_file_set_open_context(filp, ctx);
91 nfs_fscache_open_file(inode, filp);
92 err = 0;
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
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 return nfs_wb_all(inode);
129 }
130
131 #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)132 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
133 struct file *file_out, loff_t pos_out,
134 size_t count, unsigned int flags)
135 {
136 /* Only offload copy if superblock is the same */
137 if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
138 return -EXDEV;
139 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
140 return -EOPNOTSUPP;
141 if (file_inode(file_in) == file_inode(file_out))
142 return -EOPNOTSUPP;
143 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
144 }
145
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)146 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
147 struct file *file_out, loff_t pos_out,
148 size_t count, unsigned int flags)
149 {
150 ssize_t ret;
151
152 ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
153 flags);
154 if (ret == -EOPNOTSUPP || ret == -EXDEV)
155 ret = generic_copy_file_range(file_in, pos_in, file_out,
156 pos_out, count, flags);
157 return ret;
158 }
159
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)160 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
161 {
162 loff_t ret;
163
164 switch (whence) {
165 case SEEK_HOLE:
166 case SEEK_DATA:
167 ret = nfs42_proc_llseek(filep, offset, whence);
168 if (ret != -ENOTSUPP)
169 return ret;
170 /* Fall through */
171 default:
172 return nfs_file_llseek(filep, offset, whence);
173 }
174 }
175
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)176 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
177 {
178 struct inode *inode = file_inode(filep);
179 long ret;
180
181 if (!S_ISREG(inode->i_mode))
182 return -EOPNOTSUPP;
183
184 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
185 return -EOPNOTSUPP;
186
187 ret = inode_newsize_ok(inode, offset + len);
188 if (ret < 0)
189 return ret;
190
191 if (mode & FALLOC_FL_PUNCH_HOLE)
192 return nfs42_proc_deallocate(filep, offset, len);
193 return nfs42_proc_allocate(filep, offset, len);
194 }
195
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)196 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
197 struct file *dst_file, loff_t dst_off, loff_t count,
198 unsigned int remap_flags)
199 {
200 struct inode *dst_inode = file_inode(dst_file);
201 struct nfs_server *server = NFS_SERVER(dst_inode);
202 struct inode *src_inode = file_inode(src_file);
203 unsigned int bs = server->clone_blksize;
204 bool same_inode = false;
205 int ret;
206
207 /* NFS does not support deduplication. */
208 if (remap_flags & REMAP_FILE_DEDUP)
209 return -EOPNOTSUPP;
210
211 if (remap_flags & ~REMAP_FILE_ADVISORY)
212 return -EINVAL;
213
214 /* check alignment w.r.t. clone_blksize */
215 ret = -EINVAL;
216 if (bs) {
217 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
218 goto out;
219 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
220 goto out;
221 }
222
223 if (src_inode == dst_inode)
224 same_inode = true;
225
226 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
227 if (same_inode) {
228 inode_lock(src_inode);
229 } else if (dst_inode < src_inode) {
230 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
231 inode_lock_nested(src_inode, I_MUTEX_CHILD);
232 } else {
233 inode_lock_nested(src_inode, I_MUTEX_PARENT);
234 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
235 }
236
237 /* flush all pending writes on both src and dst so that server
238 * has the latest data */
239 ret = nfs_sync_inode(src_inode);
240 if (ret)
241 goto out_unlock;
242 ret = nfs_sync_inode(dst_inode);
243 if (ret)
244 goto out_unlock;
245
246 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
247
248 /* truncate inode page cache of the dst range so that future reads can fetch
249 * new data from server */
250 if (!ret)
251 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
252
253 out_unlock:
254 if (same_inode) {
255 inode_unlock(src_inode);
256 } else if (dst_inode < src_inode) {
257 inode_unlock(src_inode);
258 inode_unlock(dst_inode);
259 } else {
260 inode_unlock(dst_inode);
261 inode_unlock(src_inode);
262 }
263 out:
264 return ret < 0 ? ret : count;
265 }
266 #endif /* CONFIG_NFS_V4_2 */
267
268 const struct file_operations nfs4_file_operations = {
269 .read_iter = nfs_file_read,
270 .write_iter = nfs_file_write,
271 .mmap = nfs_file_mmap,
272 .open = nfs4_file_open,
273 .flush = nfs4_file_flush,
274 .release = nfs_file_release,
275 .fsync = nfs_file_fsync,
276 .lock = nfs_lock,
277 .flock = nfs_flock,
278 .splice_read = generic_file_splice_read,
279 .splice_write = iter_file_splice_write,
280 .check_flags = nfs_check_flags,
281 .setlease = simple_nosetlease,
282 #ifdef CONFIG_NFS_V4_2
283 .copy_file_range = nfs4_copy_file_range,
284 .llseek = nfs4_file_llseek,
285 .fallocate = nfs42_fallocate,
286 .remap_file_range = nfs42_remap_file_range,
287 #else
288 .llseek = nfs_file_llseek,
289 #endif
290 };
291