blob: e6bc022568f318640f9692032a1ccab345ad03dc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/errno.h>
17#include <linux/smp_lock.h>
18#include <linux/string.h>
19#include <asm/uaccess.h>
20
21#include <linux/coda.h>
22#include <linux/coda_linux.h>
23#include <linux/coda_fs_i.h>
24#include <linux/coda_psdev.h>
25#include <linux/coda_proc.h>
26
27/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
28 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
29static int use_coda_close;
30
31static ssize_t
32coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
33{
34 struct coda_file_info *cfi;
35 struct file *host_file;
36
37 cfi = CODA_FTOC(coda_file);
38 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
39 host_file = cfi->cfi_container;
40
41 if (!host_file->f_op || !host_file->f_op->read)
42 return -EINVAL;
43
44 return host_file->f_op->read(host_file, buf, count, ppos);
45}
46
47static ssize_t
48coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count,
49 read_actor_t actor, void *target)
50{
51 struct coda_file_info *cfi;
52 struct file *host_file;
53
54 cfi = CODA_FTOC(coda_file);
55 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
56 host_file = cfi->cfi_container;
57
58 if (!host_file->f_op || !host_file->f_op->sendfile)
59 return -EINVAL;
60
61 return host_file->f_op->sendfile(host_file, ppos, count, actor, target);
62}
63
64static ssize_t
65coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
66{
67 struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode;
68 struct coda_file_info *cfi;
69 struct file *host_file;
70 ssize_t ret;
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 || !host_file->f_op->write)
77 return -EINVAL;
78
79 host_inode = host_file->f_dentry->d_inode;
80 down(&coda_inode->i_sem);
81
82 ret = host_file->f_op->write(host_file, buf, count, ppos);
83
84 coda_inode->i_size = host_inode->i_size;
85 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
86 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
87 up(&coda_inode->i_sem);
88
89 return ret;
90}
91
92static int
93coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
94{
95 struct coda_file_info *cfi;
96 struct coda_inode_info *cii;
97 struct file *host_file;
98 struct inode *coda_inode, *host_inode;
99
100 cfi = CODA_FTOC(coda_file);
101 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
102 host_file = cfi->cfi_container;
103
104 if (!host_file->f_op || !host_file->f_op->mmap)
105 return -ENODEV;
106
107 coda_inode = coda_file->f_dentry->d_inode;
108 host_inode = host_file->f_dentry->d_inode;
109 coda_file->f_mapping = host_file->f_mapping;
110 if (coda_inode->i_mapping == &coda_inode->i_data)
111 coda_inode->i_mapping = host_inode->i_mapping;
112
113 /* only allow additional mmaps as long as userspace isn't changing
114 * the container file on us! */
115 else if (coda_inode->i_mapping != host_inode->i_mapping)
116 return -EBUSY;
117
118 /* keep track of how often the coda_inode/host_file has been mmapped */
119 cii = ITOC(coda_inode);
120 cii->c_mapcount++;
121 cfi->cfi_mapcount++;
122
123 return host_file->f_op->mmap(host_file, vma);
124}
125
126int coda_open(struct inode *coda_inode, struct file *coda_file)
127{
128 struct file *host_file = NULL;
129 int error;
130 unsigned short flags = coda_file->f_flags & (~O_EXCL);
131 unsigned short coda_flags = coda_flags_to_cflags(flags);
132 struct coda_file_info *cfi;
133
134 coda_vfs_stat.open++;
135
136 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
137 if (!cfi) {
138 unlock_kernel();
139 return -ENOMEM;
140 }
141
142 lock_kernel();
143
144 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
145 &host_file);
146 if (error || !host_file) {
147 kfree(cfi);
148 unlock_kernel();
149 return error;
150 }
151
152 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
153
154 cfi->cfi_magic = CODA_MAGIC;
155 cfi->cfi_mapcount = 0;
156 cfi->cfi_container = host_file;
157
158 BUG_ON(coda_file->private_data != NULL);
159 coda_file->private_data = cfi;
160
161 unlock_kernel();
162 return 0;
163}
164
165int coda_flush(struct file *coda_file)
166{
167 unsigned short flags = coda_file->f_flags & ~O_EXCL;
168 unsigned short coda_flags = coda_flags_to_cflags(flags);
169 struct coda_file_info *cfi;
170 struct inode *coda_inode;
171 int err = 0, fcnt;
172
173 lock_kernel();
174
175 coda_vfs_stat.flush++;
176
177 /* last close semantics */
178 fcnt = file_count(coda_file);
179 if (fcnt > 1)
180 goto out;
181
182 /* No need to make an upcall when we have not made any modifications
183 * to the file */
184 if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
185 goto out;
186
187 if (use_coda_close)
188 goto out;
189
190 cfi = CODA_FTOC(coda_file);
191 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
192
193 coda_inode = coda_file->f_dentry->d_inode;
194
195 err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
196 coda_file->f_uid);
197
198 if (err == -EOPNOTSUPP) {
199 use_coda_close = 1;
200 err = 0;
201 }
202
203out:
204 unlock_kernel();
205 return err;
206}
207
208int coda_release(struct inode *coda_inode, struct file *coda_file)
209{
210 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
211 unsigned short coda_flags = coda_flags_to_cflags(flags);
212 struct coda_file_info *cfi;
213 struct coda_inode_info *cii;
214 struct inode *host_inode;
215 int err = 0;
216
217 lock_kernel();
218 coda_vfs_stat.release++;
219
220 if (!use_coda_close) {
221 err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
222 coda_flags);
223 if (err == -EOPNOTSUPP) {
224 use_coda_close = 1;
225 err = 0;
226 }
227 }
228
229 cfi = CODA_FTOC(coda_file);
230 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
231
232 if (use_coda_close)
233 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
234 coda_flags, coda_file->f_uid);
235
236 host_inode = cfi->cfi_container->f_dentry->d_inode;
237 cii = ITOC(coda_inode);
238
239 /* did we mmap this file? */
240 if (coda_inode->i_mapping == &host_inode->i_data) {
241 cii->c_mapcount -= cfi->cfi_mapcount;
242 if (!cii->c_mapcount)
243 coda_inode->i_mapping = &coda_inode->i_data;
244 }
245
246 fput(cfi->cfi_container);
247 kfree(coda_file->private_data);
248 coda_file->private_data = NULL;
249
250 unlock_kernel();
251 return err;
252}
253
254int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
255{
256 struct file *host_file;
257 struct dentry *host_dentry;
258 struct inode *host_inode, *coda_inode = coda_dentry->d_inode;
259 struct coda_file_info *cfi;
260 int err = 0;
261
262 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
263 S_ISLNK(coda_inode->i_mode)))
264 return -EINVAL;
265
266 cfi = CODA_FTOC(coda_file);
267 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
268 host_file = cfi->cfi_container;
269
270 coda_vfs_stat.fsync++;
271
272 if (host_file->f_op && host_file->f_op->fsync) {
273 host_dentry = host_file->f_dentry;
274 host_inode = host_dentry->d_inode;
275 down(&host_inode->i_sem);
276 err = host_file->f_op->fsync(host_file, host_dentry, datasync);
277 up(&host_inode->i_sem);
278 }
279
280 if ( !err && !datasync ) {
281 lock_kernel();
282 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
283 unlock_kernel();
284 }
285
286 return err;
287}
288
289struct file_operations coda_file_operations = {
290 .llseek = generic_file_llseek,
291 .read = coda_file_read,
292 .write = coda_file_write,
293 .mmap = coda_file_mmap,
294 .open = coda_open,
295 .flush = coda_flush,
296 .release = coda_release,
297 .fsync = coda_fsync,
298 .sendfile = coda_file_sendfile,
299};
300