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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
24#include <linux/coda.h>
25#include <linux/coda_psdev.h>
26
27#include "coda_linux.h"
28#include "coda_int.h"
29
30static ssize_t
31coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
32{
33 struct file *coda_file = iocb->ki_filp;
34 struct coda_file_info *cfi = CODA_FTOC(coda_file);
35
36 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
37
38 return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0);
39}
40
41static ssize_t
42coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
43{
44 struct file *coda_file = iocb->ki_filp;
45 struct inode *coda_inode = file_inode(coda_file);
46 struct coda_file_info *cfi = CODA_FTOC(coda_file);
47 struct file *host_file;
48 ssize_t ret;
49
50 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
51
52 host_file = cfi->cfi_container;
53 file_start_write(host_file);
54 inode_lock(coda_inode);
55 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0);
56 coda_inode->i_size = file_inode(host_file)->i_size;
57 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
58 coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode);
59 inode_unlock(coda_inode);
60 file_end_write(host_file);
61 return ret;
62}
63
64static int
65coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
66{
67 struct coda_file_info *cfi;
68 struct coda_inode_info *cii;
69 struct file *host_file;
70 struct inode *coda_inode, *host_inode;
71
72 cfi = CODA_FTOC(coda_file);
73 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
74 host_file = cfi->cfi_container;
75
76 if (!host_file->f_op->mmap)
77 return -ENODEV;
78
79 coda_inode = file_inode(coda_file);
80 host_inode = file_inode(host_file);
81
82 cii = ITOC(coda_inode);
83 spin_lock(&cii->c_lock);
84 coda_file->f_mapping = host_file->f_mapping;
85 if (coda_inode->i_mapping == &coda_inode->i_data)
86 coda_inode->i_mapping = host_inode->i_mapping;
87
88 /* only allow additional mmaps as long as userspace isn't changing
89 * the container file on us! */
90 else if (coda_inode->i_mapping != host_inode->i_mapping) {
91 spin_unlock(&cii->c_lock);
92 return -EBUSY;
93 }
94
95 /* keep track of how often the coda_inode/host_file has been mmapped */
96 cii->c_mapcount++;
97 cfi->cfi_mapcount++;
98 spin_unlock(&cii->c_lock);
99
100 return call_mmap(host_file, vma);
101}
102
103int coda_open(struct inode *coda_inode, struct file *coda_file)
104{
105 struct file *host_file = NULL;
106 int error;
107 unsigned short flags = coda_file->f_flags & (~O_EXCL);
108 unsigned short coda_flags = coda_flags_to_cflags(flags);
109 struct coda_file_info *cfi;
110
111 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
112 if (!cfi)
113 return -ENOMEM;
114
115 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
116 &host_file);
117 if (!host_file)
118 error = -EIO;
119
120 if (error) {
121 kfree(cfi);
122 return error;
123 }
124
125 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
126
127 cfi->cfi_magic = CODA_MAGIC;
128 cfi->cfi_mapcount = 0;
129 cfi->cfi_container = host_file;
130
131 BUG_ON(coda_file->private_data != NULL);
132 coda_file->private_data = cfi;
133 return 0;
134}
135
136int coda_release(struct inode *coda_inode, struct file *coda_file)
137{
138 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
139 unsigned short coda_flags = coda_flags_to_cflags(flags);
140 struct coda_file_info *cfi;
141 struct coda_inode_info *cii;
142 struct inode *host_inode;
143 int err;
144
145 cfi = CODA_FTOC(coda_file);
146 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
147
148 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
149 coda_flags, coda_file->f_cred->fsuid);
150
151 host_inode = file_inode(cfi->cfi_container);
152 cii = ITOC(coda_inode);
153
154 /* did we mmap this file? */
155 spin_lock(&cii->c_lock);
156 if (coda_inode->i_mapping == &host_inode->i_data) {
157 cii->c_mapcount -= cfi->cfi_mapcount;
158 if (!cii->c_mapcount)
159 coda_inode->i_mapping = &coda_inode->i_data;
160 }
161 spin_unlock(&cii->c_lock);
162
163 fput(cfi->cfi_container);
164 kfree(coda_file->private_data);
165 coda_file->private_data = NULL;
166
167 /* VFS fput ignores the return value from file_operations->release, so
168 * there is no use returning an error here */
169 return 0;
170}
171
172int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
173{
174 struct file *host_file;
175 struct inode *coda_inode = file_inode(coda_file);
176 struct coda_file_info *cfi;
177 int err;
178
179 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
180 S_ISLNK(coda_inode->i_mode)))
181 return -EINVAL;
182
183 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
184 if (err)
185 return err;
186 inode_lock(coda_inode);
187
188 cfi = CODA_FTOC(coda_file);
189 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
190 host_file = cfi->cfi_container;
191
192 err = vfs_fsync(host_file, datasync);
193 if (!err && !datasync)
194 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
195 inode_unlock(coda_inode);
196
197 return err;
198}
199
200const struct file_operations coda_file_operations = {
201 .llseek = generic_file_llseek,
202 .read_iter = coda_file_read_iter,
203 .write_iter = coda_file_write_iter,
204 .mmap = coda_file_mmap,
205 .open = coda_open,
206 .release = coda_release,
207 .fsync = coda_fsync,
208 .splice_read = generic_file_splice_read,
209};
210
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->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 = file_inode(coda_file);
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->write)
79 return -EINVAL;
80
81 host_inode = file_inode(host_file);
82 file_start_write(host_file);
83 mutex_lock(&coda_inode->i_mutex);
84
85 ret = host_file->f_op->write(host_file, buf, count, ppos);
86
87 coda_inode->i_size = host_inode->i_size;
88 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
89 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
90 mutex_unlock(&coda_inode->i_mutex);
91 file_end_write(host_file);
92
93 return ret;
94}
95
96static int
97coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
98{
99 struct coda_file_info *cfi;
100 struct coda_inode_info *cii;
101 struct file *host_file;
102 struct inode *coda_inode, *host_inode;
103
104 cfi = CODA_FTOC(coda_file);
105 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
106 host_file = cfi->cfi_container;
107
108 if (!host_file->f_op->mmap)
109 return -ENODEV;
110
111 coda_inode = file_inode(coda_file);
112 host_inode = file_inode(host_file);
113
114 cii = ITOC(coda_inode);
115 spin_lock(&cii->c_lock);
116 coda_file->f_mapping = host_file->f_mapping;
117 if (coda_inode->i_mapping == &coda_inode->i_data)
118 coda_inode->i_mapping = host_inode->i_mapping;
119
120 /* only allow additional mmaps as long as userspace isn't changing
121 * the container file on us! */
122 else if (coda_inode->i_mapping != host_inode->i_mapping) {
123 spin_unlock(&cii->c_lock);
124 return -EBUSY;
125 }
126
127 /* keep track of how often the coda_inode/host_file has been mmapped */
128 cii->c_mapcount++;
129 cfi->cfi_mapcount++;
130 spin_unlock(&cii->c_lock);
131
132 return host_file->f_op->mmap(host_file, vma);
133}
134
135int coda_open(struct inode *coda_inode, struct file *coda_file)
136{
137 struct file *host_file = NULL;
138 int error;
139 unsigned short flags = coda_file->f_flags & (~O_EXCL);
140 unsigned short coda_flags = coda_flags_to_cflags(flags);
141 struct coda_file_info *cfi;
142
143 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
144 if (!cfi)
145 return -ENOMEM;
146
147 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
148 &host_file);
149 if (!host_file)
150 error = -EIO;
151
152 if (error) {
153 kfree(cfi);
154 return error;
155 }
156
157 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
158
159 cfi->cfi_magic = CODA_MAGIC;
160 cfi->cfi_mapcount = 0;
161 cfi->cfi_container = host_file;
162
163 BUG_ON(coda_file->private_data != NULL);
164 coda_file->private_data = cfi;
165 return 0;
166}
167
168int coda_release(struct inode *coda_inode, struct file *coda_file)
169{
170 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
171 unsigned short coda_flags = coda_flags_to_cflags(flags);
172 struct coda_file_info *cfi;
173 struct coda_inode_info *cii;
174 struct inode *host_inode;
175 int err;
176
177 cfi = CODA_FTOC(coda_file);
178 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
179
180 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
181 coda_flags, coda_file->f_cred->fsuid);
182
183 host_inode = file_inode(cfi->cfi_container);
184 cii = ITOC(coda_inode);
185
186 /* did we mmap this file? */
187 spin_lock(&cii->c_lock);
188 if (coda_inode->i_mapping == &host_inode->i_data) {
189 cii->c_mapcount -= cfi->cfi_mapcount;
190 if (!cii->c_mapcount)
191 coda_inode->i_mapping = &coda_inode->i_data;
192 }
193 spin_unlock(&cii->c_lock);
194
195 fput(cfi->cfi_container);
196 kfree(coda_file->private_data);
197 coda_file->private_data = NULL;
198
199 /* VFS fput ignores the return value from file_operations->release, so
200 * there is no use returning an error here */
201 return 0;
202}
203
204int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
205{
206 struct file *host_file;
207 struct inode *coda_inode = file_inode(coda_file);
208 struct coda_file_info *cfi;
209 int err;
210
211 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
212 S_ISLNK(coda_inode->i_mode)))
213 return -EINVAL;
214
215 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
216 if (err)
217 return err;
218 mutex_lock(&coda_inode->i_mutex);
219
220 cfi = CODA_FTOC(coda_file);
221 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
222 host_file = cfi->cfi_container;
223
224 err = vfs_fsync(host_file, datasync);
225 if (!err && !datasync)
226 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
227 mutex_unlock(&coda_inode->i_mutex);
228
229 return err;
230}
231
232const struct file_operations coda_file_operations = {
233 .llseek = generic_file_llseek,
234 .read = coda_file_read,
235 .write = coda_file_write,
236 .mmap = coda_file_mmap,
237 .open = coda_open,
238 .release = coda_release,
239 .fsync = coda_fsync,
240 .splice_read = coda_file_splice_read,
241};
242