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