blob: 99dbe866816d277ba5c90ccbf04ff92567725bee [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
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080027#include "coda_int.h"
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
30 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
31static int use_coda_close;
32
33static ssize_t
34coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
35{
36 struct coda_file_info *cfi;
37 struct file *host_file;
38
39 cfi = CODA_FTOC(coda_file);
40 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
41 host_file = cfi->cfi_container;
42
43 if (!host_file->f_op || !host_file->f_op->read)
44 return -EINVAL;
45
46 return host_file->f_op->read(host_file, buf, count, ppos);
47}
48
49static ssize_t
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020050coda_file_splice_read(struct file *coda_file, loff_t *ppos,
51 struct pipe_inode_info *pipe, size_t count,
52 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
54 struct coda_file_info *cfi;
55 struct file *host_file;
56
57 cfi = CODA_FTOC(coda_file);
58 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
59 host_file = cfi->cfi_container;
60
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020061 if (!host_file->f_op || !host_file->f_op->splice_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 return -EINVAL;
63
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020064 return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065}
66
67static ssize_t
68coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
69{
Josef Sipekd4176d32006-12-08 02:36:56 -080070 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 struct coda_file_info *cfi;
72 struct file *host_file;
73 ssize_t ret;
74
75 cfi = CODA_FTOC(coda_file);
76 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
77 host_file = cfi->cfi_container;
78
79 if (!host_file->f_op || !host_file->f_op->write)
80 return -EINVAL;
81
Josef Sipekd4176d32006-12-08 02:36:56 -080082 host_inode = host_file->f_path.dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080083 mutex_lock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
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;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080090 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92 return ret;
93}
94
95static int
96coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
97{
98 struct coda_file_info *cfi;
99 struct coda_inode_info *cii;
100 struct file *host_file;
101 struct inode *coda_inode, *host_inode;
102
103 cfi = CODA_FTOC(coda_file);
104 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
105 host_file = cfi->cfi_container;
106
107 if (!host_file->f_op || !host_file->f_op->mmap)
108 return -ENODEV;
109
Josef Sipekd4176d32006-12-08 02:36:56 -0800110 coda_inode = coda_file->f_path.dentry->d_inode;
111 host_inode = host_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 coda_file->f_mapping = host_file->f_mapping;
113 if (coda_inode->i_mapping == &coda_inode->i_data)
114 coda_inode->i_mapping = host_inode->i_mapping;
115
116 /* only allow additional mmaps as long as userspace isn't changing
117 * the container file on us! */
118 else if (coda_inode->i_mapping != host_inode->i_mapping)
119 return -EBUSY;
120
121 /* keep track of how often the coda_inode/host_file has been mmapped */
122 cii = ITOC(coda_inode);
123 cii->c_mapcount++;
124 cfi->cfi_mapcount++;
125
126 return host_file->f_op->mmap(host_file, vma);
127}
128
129int coda_open(struct inode *coda_inode, struct file *coda_file)
130{
131 struct file *host_file = NULL;
132 int error;
133 unsigned short flags = coda_file->f_flags & (~O_EXCL);
134 unsigned short coda_flags = coda_flags_to_cflags(flags);
135 struct coda_file_info *cfi;
136
137 coda_vfs_stat.open++;
138
139 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700140 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 lock_kernel();
144
145 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
146 &host_file);
147 if (error || !host_file) {
148 kfree(cfi);
149 unlock_kernel();
150 return error;
151 }
152
153 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
154
155 cfi->cfi_magic = CODA_MAGIC;
156 cfi->cfi_mapcount = 0;
157 cfi->cfi_container = host_file;
158
159 BUG_ON(coda_file->private_data != NULL);
160 coda_file->private_data = cfi;
161
162 unlock_kernel();
163 return 0;
164}
165
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700166int coda_flush(struct file *coda_file, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
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 inode *coda_inode;
172 int err = 0, fcnt;
173
174 lock_kernel();
175
176 coda_vfs_stat.flush++;
177
178 /* last close semantics */
179 fcnt = file_count(coda_file);
180 if (fcnt > 1)
181 goto out;
182
183 /* No need to make an upcall when we have not made any modifications
184 * to the file */
185 if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
186 goto out;
187
188 if (use_coda_close)
189 goto out;
190
191 cfi = CODA_FTOC(coda_file);
192 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
193
Josef Sipekd4176d32006-12-08 02:36:56 -0800194 coda_inode = coda_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196 err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
197 coda_file->f_uid);
198
199 if (err == -EOPNOTSUPP) {
200 use_coda_close = 1;
201 err = 0;
202 }
203
204out:
205 unlock_kernel();
206 return err;
207}
208
209int coda_release(struct inode *coda_inode, struct file *coda_file)
210{
211 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
212 unsigned short coda_flags = coda_flags_to_cflags(flags);
213 struct coda_file_info *cfi;
214 struct coda_inode_info *cii;
215 struct inode *host_inode;
216 int err = 0;
217
218 lock_kernel();
219 coda_vfs_stat.release++;
220
221 if (!use_coda_close) {
222 err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
223 coda_flags);
224 if (err == -EOPNOTSUPP) {
225 use_coda_close = 1;
226 err = 0;
227 }
228 }
229
230 cfi = CODA_FTOC(coda_file);
231 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
232
233 if (use_coda_close)
234 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
235 coda_flags, coda_file->f_uid);
236
Josef Sipekd4176d32006-12-08 02:36:56 -0800237 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 cii = ITOC(coda_inode);
239
240 /* did we mmap this file? */
241 if (coda_inode->i_mapping == &host_inode->i_data) {
242 cii->c_mapcount -= cfi->cfi_mapcount;
243 if (!cii->c_mapcount)
244 coda_inode->i_mapping = &coda_inode->i_data;
245 }
246
247 fput(cfi->cfi_container);
248 kfree(coda_file->private_data);
249 coda_file->private_data = NULL;
250
251 unlock_kernel();
252 return err;
253}
254
255int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
256{
257 struct file *host_file;
258 struct dentry *host_dentry;
259 struct inode *host_inode, *coda_inode = coda_dentry->d_inode;
260 struct coda_file_info *cfi;
261 int err = 0;
262
263 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
264 S_ISLNK(coda_inode->i_mode)))
265 return -EINVAL;
266
267 cfi = CODA_FTOC(coda_file);
268 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
269 host_file = cfi->cfi_container;
270
271 coda_vfs_stat.fsync++;
272
273 if (host_file->f_op && host_file->f_op->fsync) {
Josef Sipekd4176d32006-12-08 02:36:56 -0800274 host_dentry = host_file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 host_inode = host_dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800276 mutex_lock(&host_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 err = host_file->f_op->fsync(host_file, host_dentry, datasync);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800278 mutex_unlock(&host_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 }
280
281 if ( !err && !datasync ) {
282 lock_kernel();
283 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
284 unlock_kernel();
285 }
286
287 return err;
288}
289
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800290const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 .llseek = generic_file_llseek,
292 .read = coda_file_read,
293 .write = coda_file_write,
294 .mmap = coda_file_mmap,
295 .open = coda_open,
296 .flush = coda_flush,
297 .release = coda_release,
298 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200299 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300};
301