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 vfs_fsync(file, 0);
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 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
137 return -EOPNOTSUPP;
138 if (file_inode(file_in) == file_inode(file_out))
139 return -EOPNOTSUPP;
140 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
141 }
142
nfs4_file_llseek(struct file * filep,loff_t offset,int whence)143 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
144 {
145 loff_t ret;
146
147 switch (whence) {
148 case SEEK_HOLE:
149 case SEEK_DATA:
150 ret = nfs42_proc_llseek(filep, offset, whence);
151 if (ret != -EOPNOTSUPP)
152 return ret;
153 /* Fall through */
154 default:
155 return nfs_file_llseek(filep, offset, whence);
156 }
157 }
158
nfs42_fallocate(struct file * filep,int mode,loff_t offset,loff_t len)159 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
160 {
161 struct inode *inode = file_inode(filep);
162 long ret;
163
164 if (!S_ISREG(inode->i_mode))
165 return -EOPNOTSUPP;
166
167 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
168 return -EOPNOTSUPP;
169
170 ret = inode_newsize_ok(inode, offset + len);
171 if (ret < 0)
172 return ret;
173
174 if (mode & FALLOC_FL_PUNCH_HOLE)
175 return nfs42_proc_deallocate(filep, offset, len);
176 return nfs42_proc_allocate(filep, offset, len);
177 }
178
nfs42_clone_file_range(struct file * src_file,loff_t src_off,struct file * dst_file,loff_t dst_off,u64 count)179 static int nfs42_clone_file_range(struct file *src_file, loff_t src_off,
180 struct file *dst_file, loff_t dst_off, u64 count)
181 {
182 struct inode *dst_inode = file_inode(dst_file);
183 struct nfs_server *server = NFS_SERVER(dst_inode);
184 struct inode *src_inode = file_inode(src_file);
185 unsigned int bs = server->clone_blksize;
186 bool same_inode = false;
187 int ret;
188
189 /* check alignment w.r.t. clone_blksize */
190 ret = -EINVAL;
191 if (bs) {
192 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
193 goto out;
194 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
195 goto out;
196 }
197
198 if (src_inode == dst_inode)
199 same_inode = true;
200
201 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
202 if (same_inode) {
203 inode_lock(src_inode);
204 } else if (dst_inode < src_inode) {
205 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
206 inode_lock_nested(src_inode, I_MUTEX_CHILD);
207 } else {
208 inode_lock_nested(src_inode, I_MUTEX_PARENT);
209 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
210 }
211
212 /* flush all pending writes on both src and dst so that server
213 * has the latest data */
214 ret = nfs_sync_inode(src_inode);
215 if (ret)
216 goto out_unlock;
217 ret = nfs_sync_inode(dst_inode);
218 if (ret)
219 goto out_unlock;
220
221 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
222
223 /* truncate inode page cache of the dst range so that future reads can fetch
224 * new data from server */
225 if (!ret)
226 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
227
228 out_unlock:
229 if (same_inode) {
230 inode_unlock(src_inode);
231 } else if (dst_inode < src_inode) {
232 inode_unlock(src_inode);
233 inode_unlock(dst_inode);
234 } else {
235 inode_unlock(dst_inode);
236 inode_unlock(src_inode);
237 }
238 out:
239 return ret;
240 }
241 #endif /* CONFIG_NFS_V4_2 */
242
243 const struct file_operations nfs4_file_operations = {
244 .read_iter = nfs_file_read,
245 .write_iter = nfs_file_write,
246 .mmap = nfs_file_mmap,
247 .open = nfs4_file_open,
248 .flush = nfs4_file_flush,
249 .release = nfs_file_release,
250 .fsync = nfs_file_fsync,
251 .lock = nfs_lock,
252 .flock = nfs_flock,
253 .splice_read = generic_file_splice_read,
254 .splice_write = iter_file_splice_write,
255 .check_flags = nfs_check_flags,
256 .setlease = simple_nosetlease,
257 #ifdef CONFIG_NFS_V4_2
258 .copy_file_range = nfs4_copy_file_range,
259 .llseek = nfs4_file_llseek,
260 .fallocate = nfs42_fallocate,
261 .clone_file_range = nfs42_clone_file_range,
262 #else
263 .llseek = nfs_file_llseek,
264 #endif
265 };
266