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