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1/*
2 * File operations for Coda.
3 * Original version: (C) 1996 Peter Braam
4 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
5 *
6 * Carnegie Mellon encourages users of this code to contribute improvements
7 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/time.h>
13#include <linux/file.h>
14#include <linux/fs.h>
15#include <linux/stat.h>
16#include <linux/cred.h>
17#include <linux/errno.h>
18#include <linux/spinlock.h>
19#include <linux/string.h>
20#include <linux/slab.h>
21#include <linux/uaccess.h>
22
23#include <linux/coda.h>
24#include <linux/coda_psdev.h>
25
26#include "coda_linux.h"
27#include "coda_int.h"
28
29static ssize_t
30coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
31{
32 struct file *coda_file = iocb->ki_filp;
33 struct coda_file_info *cfi = CODA_FTOC(coda_file);
34
35 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
36
37 return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
38}
39
40static ssize_t
41coda_file_splice_read(struct file *coda_file, loff_t *ppos,
42 struct pipe_inode_info *pipe, size_t count,
43 unsigned int flags)
44{
45 ssize_t (*splice_read)(struct file *, loff_t *,
46 struct pipe_inode_info *, size_t, unsigned int);
47 struct coda_file_info *cfi;
48 struct file *host_file;
49
50 cfi = CODA_FTOC(coda_file);
51 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
52 host_file = cfi->cfi_container;
53
54 splice_read = host_file->f_op->splice_read;
55 if (!splice_read)
56 splice_read = default_file_splice_read;
57
58 return splice_read(host_file, ppos, pipe, count, flags);
59}
60
61static ssize_t
62coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
63{
64 struct file *coda_file = iocb->ki_filp;
65 struct inode *coda_inode = file_inode(coda_file);
66 struct coda_file_info *cfi = CODA_FTOC(coda_file);
67 struct file *host_file;
68 ssize_t ret;
69
70 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
71
72 host_file = cfi->cfi_container;
73 file_start_write(host_file);
74 inode_lock(coda_inode);
75 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
76 coda_inode->i_size = file_inode(host_file)->i_size;
77 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
78 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
79 inode_unlock(coda_inode);
80 file_end_write(host_file);
81 return ret;
82}
83
84static int
85coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
86{
87 struct coda_file_info *cfi;
88 struct coda_inode_info *cii;
89 struct file *host_file;
90 struct inode *coda_inode, *host_inode;
91
92 cfi = CODA_FTOC(coda_file);
93 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
94 host_file = cfi->cfi_container;
95
96 if (!host_file->f_op->mmap)
97 return -ENODEV;
98
99 coda_inode = file_inode(coda_file);
100 host_inode = file_inode(host_file);
101
102 cii = ITOC(coda_inode);
103 spin_lock(&cii->c_lock);
104 coda_file->f_mapping = host_file->f_mapping;
105 if (coda_inode->i_mapping == &coda_inode->i_data)
106 coda_inode->i_mapping = host_inode->i_mapping;
107
108 /* only allow additional mmaps as long as userspace isn't changing
109 * the container file on us! */
110 else if (coda_inode->i_mapping != host_inode->i_mapping) {
111 spin_unlock(&cii->c_lock);
112 return -EBUSY;
113 }
114
115 /* keep track of how often the coda_inode/host_file has been mmapped */
116 cii->c_mapcount++;
117 cfi->cfi_mapcount++;
118 spin_unlock(&cii->c_lock);
119
120 return host_file->f_op->mmap(host_file, vma);
121}
122
123int coda_open(struct inode *coda_inode, struct file *coda_file)
124{
125 struct file *host_file = NULL;
126 int error;
127 unsigned short flags = coda_file->f_flags & (~O_EXCL);
128 unsigned short coda_flags = coda_flags_to_cflags(flags);
129 struct coda_file_info *cfi;
130
131 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
132 if (!cfi)
133 return -ENOMEM;
134
135 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
136 &host_file);
137 if (!host_file)
138 error = -EIO;
139
140 if (error) {
141 kfree(cfi);
142 return error;
143 }
144
145 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
146
147 cfi->cfi_magic = CODA_MAGIC;
148 cfi->cfi_mapcount = 0;
149 cfi->cfi_container = host_file;
150
151 BUG_ON(coda_file->private_data != NULL);
152 coda_file->private_data = cfi;
153 return 0;
154}
155
156int coda_release(struct inode *coda_inode, struct file *coda_file)
157{
158 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
159 unsigned short coda_flags = coda_flags_to_cflags(flags);
160 struct coda_file_info *cfi;
161 struct coda_inode_info *cii;
162 struct inode *host_inode;
163 int err;
164
165 cfi = CODA_FTOC(coda_file);
166 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
167
168 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
169 coda_flags, coda_file->f_cred->fsuid);
170
171 host_inode = file_inode(cfi->cfi_container);
172 cii = ITOC(coda_inode);
173
174 /* did we mmap this file? */
175 spin_lock(&cii->c_lock);
176 if (coda_inode->i_mapping == &host_inode->i_data) {
177 cii->c_mapcount -= cfi->cfi_mapcount;
178 if (!cii->c_mapcount)
179 coda_inode->i_mapping = &coda_inode->i_data;
180 }
181 spin_unlock(&cii->c_lock);
182
183 fput(cfi->cfi_container);
184 kfree(coda_file->private_data);
185 coda_file->private_data = NULL;
186
187 /* VFS fput ignores the return value from file_operations->release, so
188 * there is no use returning an error here */
189 return 0;
190}
191
192int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
193{
194 struct file *host_file;
195 struct inode *coda_inode = file_inode(coda_file);
196 struct coda_file_info *cfi;
197 int err;
198
199 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
200 S_ISLNK(coda_inode->i_mode)))
201 return -EINVAL;
202
203 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
204 if (err)
205 return err;
206 inode_lock(coda_inode);
207
208 cfi = CODA_FTOC(coda_file);
209 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
210 host_file = cfi->cfi_container;
211
212 err = vfs_fsync(host_file, datasync);
213 if (!err && !datasync)
214 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
215 inode_unlock(coda_inode);
216
217 return err;
218}
219
220const struct file_operations coda_file_operations = {
221 .llseek = generic_file_llseek,
222 .read_iter = coda_file_read_iter,
223 .write_iter = coda_file_write_iter,
224 .mmap = coda_file_mmap,
225 .open = coda_open,
226 .release = coda_release,
227 .fsync = coda_fsync,
228 .splice_read = coda_file_splice_read,
229};
230
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * File operations for Coda.
4 * Original version: (C) 1996 Peter Braam
5 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
6 *
7 * Carnegie Mellon encourages users of this code to contribute improvements
8 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
9 */
10
11#include <linux/refcount.h>
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/time.h>
15#include <linux/file.h>
16#include <linux/fs.h>
17#include <linux/pagemap.h>
18#include <linux/stat.h>
19#include <linux/cred.h>
20#include <linux/errno.h>
21#include <linux/spinlock.h>
22#include <linux/string.h>
23#include <linux/slab.h>
24#include <linux/uaccess.h>
25#include <linux/uio.h>
26#include <linux/splice.h>
27
28#include <linux/coda.h>
29#include "coda_psdev.h"
30#include "coda_linux.h"
31#include "coda_int.h"
32
33struct coda_vm_ops {
34 refcount_t refcnt;
35 struct file *coda_file;
36 const struct vm_operations_struct *host_vm_ops;
37 struct vm_operations_struct vm_ops;
38};
39
40static ssize_t
41coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
42{
43 struct file *coda_file = iocb->ki_filp;
44 struct inode *coda_inode = file_inode(coda_file);
45 struct coda_file_info *cfi = coda_ftoc(coda_file);
46 loff_t ki_pos = iocb->ki_pos;
47 size_t count = iov_iter_count(to);
48 ssize_t ret;
49
50 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
51 &cfi->cfi_access_intent,
52 count, ki_pos, CODA_ACCESS_TYPE_READ);
53 if (ret)
54 goto finish_read;
55
56 ret = vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0);
57
58finish_read:
59 venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
60 &cfi->cfi_access_intent,
61 count, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
62 return ret;
63}
64
65static ssize_t
66coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
67{
68 struct file *coda_file = iocb->ki_filp;
69 struct inode *coda_inode = file_inode(coda_file);
70 struct coda_file_info *cfi = coda_ftoc(coda_file);
71 struct file *host_file = cfi->cfi_container;
72 loff_t ki_pos = iocb->ki_pos;
73 size_t count = iov_iter_count(to);
74 ssize_t ret;
75
76 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
77 &cfi->cfi_access_intent,
78 count, ki_pos, CODA_ACCESS_TYPE_WRITE);
79 if (ret)
80 goto finish_write;
81
82 inode_lock(coda_inode);
83 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0);
84 coda_inode->i_size = file_inode(host_file)->i_size;
85 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
86 inode_set_mtime_to_ts(coda_inode, inode_set_ctime_current(coda_inode));
87 inode_unlock(coda_inode);
88
89finish_write:
90 venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
91 &cfi->cfi_access_intent,
92 count, ki_pos, CODA_ACCESS_TYPE_WRITE_FINISH);
93 return ret;
94}
95
96static ssize_t
97coda_file_splice_read(struct file *coda_file, loff_t *ppos,
98 struct pipe_inode_info *pipe,
99 size_t len, unsigned int flags)
100{
101 struct inode *coda_inode = file_inode(coda_file);
102 struct coda_file_info *cfi = coda_ftoc(coda_file);
103 struct file *in = cfi->cfi_container;
104 loff_t ki_pos = *ppos;
105 ssize_t ret;
106
107 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
108 &cfi->cfi_access_intent,
109 len, ki_pos, CODA_ACCESS_TYPE_READ);
110 if (ret)
111 goto finish_read;
112
113 ret = vfs_splice_read(in, ppos, pipe, len, flags);
114
115finish_read:
116 venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
117 &cfi->cfi_access_intent,
118 len, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
119 return ret;
120}
121
122static void
123coda_vm_open(struct vm_area_struct *vma)
124{
125 struct coda_vm_ops *cvm_ops =
126 container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
127
128 refcount_inc(&cvm_ops->refcnt);
129
130 if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open)
131 cvm_ops->host_vm_ops->open(vma);
132}
133
134static void
135coda_vm_close(struct vm_area_struct *vma)
136{
137 struct coda_vm_ops *cvm_ops =
138 container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
139
140 if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close)
141 cvm_ops->host_vm_ops->close(vma);
142
143 if (refcount_dec_and_test(&cvm_ops->refcnt)) {
144 vma->vm_ops = cvm_ops->host_vm_ops;
145 fput(cvm_ops->coda_file);
146 kfree(cvm_ops);
147 }
148}
149
150static int
151coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
152{
153 struct inode *coda_inode = file_inode(coda_file);
154 struct coda_file_info *cfi = coda_ftoc(coda_file);
155 struct file *host_file = cfi->cfi_container;
156 struct inode *host_inode = file_inode(host_file);
157 struct coda_inode_info *cii;
158 struct coda_vm_ops *cvm_ops;
159 loff_t ppos;
160 size_t count;
161 int ret;
162
163 if (!host_file->f_op->mmap)
164 return -ENODEV;
165
166 if (WARN_ON(coda_file != vma->vm_file))
167 return -EIO;
168
169 count = vma->vm_end - vma->vm_start;
170 ppos = vma->vm_pgoff * PAGE_SIZE;
171
172 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
173 &cfi->cfi_access_intent,
174 count, ppos, CODA_ACCESS_TYPE_MMAP);
175 if (ret)
176 return ret;
177
178 cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL);
179 if (!cvm_ops)
180 return -ENOMEM;
181
182 cii = ITOC(coda_inode);
183 spin_lock(&cii->c_lock);
184 coda_file->f_mapping = host_file->f_mapping;
185 if (coda_inode->i_mapping == &coda_inode->i_data)
186 coda_inode->i_mapping = host_inode->i_mapping;
187
188 /* only allow additional mmaps as long as userspace isn't changing
189 * the container file on us! */
190 else if (coda_inode->i_mapping != host_inode->i_mapping) {
191 spin_unlock(&cii->c_lock);
192 kfree(cvm_ops);
193 return -EBUSY;
194 }
195
196 /* keep track of how often the coda_inode/host_file has been mmapped */
197 cii->c_mapcount++;
198 cfi->cfi_mapcount++;
199 spin_unlock(&cii->c_lock);
200
201 vma->vm_file = get_file(host_file);
202 ret = call_mmap(vma->vm_file, vma);
203
204 if (ret) {
205 /* if call_mmap fails, our caller will put host_file so we
206 * should drop the reference to the coda_file that we got.
207 */
208 fput(coda_file);
209 kfree(cvm_ops);
210 } else {
211 /* here we add redirects for the open/close vm_operations */
212 cvm_ops->host_vm_ops = vma->vm_ops;
213 if (vma->vm_ops)
214 cvm_ops->vm_ops = *vma->vm_ops;
215
216 cvm_ops->vm_ops.open = coda_vm_open;
217 cvm_ops->vm_ops.close = coda_vm_close;
218 cvm_ops->coda_file = coda_file;
219 refcount_set(&cvm_ops->refcnt, 1);
220
221 vma->vm_ops = &cvm_ops->vm_ops;
222 }
223 return ret;
224}
225
226int coda_open(struct inode *coda_inode, struct file *coda_file)
227{
228 struct file *host_file = NULL;
229 int error;
230 unsigned short flags = coda_file->f_flags & (~O_EXCL);
231 unsigned short coda_flags = coda_flags_to_cflags(flags);
232 struct coda_file_info *cfi;
233
234 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
235 if (!cfi)
236 return -ENOMEM;
237
238 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
239 &host_file);
240 if (!host_file)
241 error = -EIO;
242
243 if (error) {
244 kfree(cfi);
245 return error;
246 }
247
248 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
249
250 cfi->cfi_magic = CODA_MAGIC;
251 cfi->cfi_mapcount = 0;
252 cfi->cfi_container = host_file;
253 /* assume access intents are supported unless we hear otherwise */
254 cfi->cfi_access_intent = true;
255
256 BUG_ON(coda_file->private_data != NULL);
257 coda_file->private_data = cfi;
258 return 0;
259}
260
261int coda_release(struct inode *coda_inode, struct file *coda_file)
262{
263 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
264 unsigned short coda_flags = coda_flags_to_cflags(flags);
265 struct coda_file_info *cfi;
266 struct coda_inode_info *cii;
267 struct inode *host_inode;
268
269 cfi = coda_ftoc(coda_file);
270
271 venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
272 coda_flags, coda_file->f_cred->fsuid);
273
274 host_inode = file_inode(cfi->cfi_container);
275 cii = ITOC(coda_inode);
276
277 /* did we mmap this file? */
278 spin_lock(&cii->c_lock);
279 if (coda_inode->i_mapping == &host_inode->i_data) {
280 cii->c_mapcount -= cfi->cfi_mapcount;
281 if (!cii->c_mapcount)
282 coda_inode->i_mapping = &coda_inode->i_data;
283 }
284 spin_unlock(&cii->c_lock);
285
286 fput(cfi->cfi_container);
287 kfree(coda_file->private_data);
288 coda_file->private_data = NULL;
289
290 /* VFS fput ignores the return value from file_operations->release, so
291 * there is no use returning an error here */
292 return 0;
293}
294
295int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
296{
297 struct file *host_file;
298 struct inode *coda_inode = file_inode(coda_file);
299 struct coda_file_info *cfi;
300 int err;
301
302 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
303 S_ISLNK(coda_inode->i_mode)))
304 return -EINVAL;
305
306 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
307 if (err)
308 return err;
309 inode_lock(coda_inode);
310
311 cfi = coda_ftoc(coda_file);
312 host_file = cfi->cfi_container;
313
314 err = vfs_fsync(host_file, datasync);
315 if (!err && !datasync)
316 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
317 inode_unlock(coda_inode);
318
319 return err;
320}
321
322const struct file_operations coda_file_operations = {
323 .llseek = generic_file_llseek,
324 .read_iter = coda_file_read_iter,
325 .write_iter = coda_file_write_iter,
326 .mmap = coda_file_mmap,
327 .open = coda_open,
328 .release = coda_release,
329 .fsync = coda_fsync,
330 .splice_read = coda_file_splice_read,
331};