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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>
Randy Dunlap7596b272008-11-19 11:30:27 -080016#include <linux/cred.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/errno.h>
18#include <linux/smp_lock.h>
19#include <linux/string.h>
20#include <asm/uaccess.h>
21
22#include <linux/coda.h>
23#include <linux/coda_linux.h>
24#include <linux/coda_fs_i.h>
25#include <linux/coda_psdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080027#include "coda_int.h"
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029static 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
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020046coda_file_splice_read(struct file *coda_file, loff_t *ppos,
47 struct pipe_inode_info *pipe, size_t count,
48 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
50 struct coda_file_info *cfi;
51 struct file *host_file;
52
53 cfi = CODA_FTOC(coda_file);
54 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
55 host_file = cfi->cfi_container;
56
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020057 if (!host_file->f_op || !host_file->f_op->splice_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 return -EINVAL;
59
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020060 return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061}
62
63static ssize_t
64coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
65{
Josef Sipekd4176d32006-12-08 02:36:56 -080066 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 struct coda_file_info *cfi;
68 struct file *host_file;
69 ssize_t ret;
70
71 cfi = CODA_FTOC(coda_file);
72 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
73 host_file = cfi->cfi_container;
74
75 if (!host_file->f_op || !host_file->f_op->write)
76 return -EINVAL;
77
Josef Sipekd4176d32006-12-08 02:36:56 -080078 host_inode = host_file->f_path.dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080079 mutex_lock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 ret = host_file->f_op->write(host_file, buf, count, ppos);
82
83 coda_inode->i_size = host_inode->i_size;
84 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
85 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080086 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88 return ret;
89}
90
91static int
92coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
93{
94 struct coda_file_info *cfi;
95 struct coda_inode_info *cii;
96 struct file *host_file;
97 struct inode *coda_inode, *host_inode;
98
99 cfi = CODA_FTOC(coda_file);
100 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
101 host_file = cfi->cfi_container;
102
103 if (!host_file->f_op || !host_file->f_op->mmap)
104 return -ENODEV;
105
Josef Sipekd4176d32006-12-08 02:36:56 -0800106 coda_inode = coda_file->f_path.dentry->d_inode;
107 host_inode = host_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 coda_file->f_mapping = host_file->f_mapping;
109 if (coda_inode->i_mapping == &coda_inode->i_data)
110 coda_inode->i_mapping = host_inode->i_mapping;
111
112 /* only allow additional mmaps as long as userspace isn't changing
113 * the container file on us! */
114 else if (coda_inode->i_mapping != host_inode->i_mapping)
115 return -EBUSY;
116
117 /* keep track of how often the coda_inode/host_file has been mmapped */
118 cii = ITOC(coda_inode);
119 cii->c_mapcount++;
120 cfi->cfi_mapcount++;
121
122 return host_file->f_op->mmap(host_file, vma);
123}
124
125int coda_open(struct inode *coda_inode, struct file *coda_file)
126{
127 struct file *host_file = NULL;
128 int error;
129 unsigned short flags = coda_file->f_flags & (~O_EXCL);
130 unsigned short coda_flags = coda_flags_to_cflags(flags);
131 struct coda_file_info *cfi;
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700134 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 lock_kernel();
138
139 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
Jan Harkes38c2e432007-07-19 01:48:41 -0700140 &host_file);
141 if (!host_file)
142 error = -EIO;
143
144 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 kfree(cfi);
146 unlock_kernel();
147 return error;
148 }
149
150 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
151
152 cfi->cfi_magic = CODA_MAGIC;
153 cfi->cfi_mapcount = 0;
154 cfi->cfi_container = host_file;
155
156 BUG_ON(coda_file->private_data != NULL);
157 coda_file->private_data = cfi;
158
159 unlock_kernel();
160 return 0;
161}
162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163int coda_release(struct inode *coda_inode, struct file *coda_file)
164{
165 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
166 unsigned short coda_flags = coda_flags_to_cflags(flags);
167 struct coda_file_info *cfi;
168 struct coda_inode_info *cii;
169 struct inode *host_inode;
170 int err = 0;
171
172 lock_kernel();
Jan Harkes3cf01f22007-07-19 01:48:51 -0700173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 cfi = CODA_FTOC(coda_file);
175 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
176
Jan Harkesd3fec422007-07-21 04:37:26 -0700177 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
David Howellsd76b0d92008-11-14 10:39:25 +1100178 coda_flags, coda_file->f_cred->fsuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Josef Sipekd4176d32006-12-08 02:36:56 -0800180 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 cii = ITOC(coda_inode);
182
183 /* did we mmap this file? */
184 if (coda_inode->i_mapping == &host_inode->i_data) {
185 cii->c_mapcount -= cfi->cfi_mapcount;
186 if (!cii->c_mapcount)
187 coda_inode->i_mapping = &coda_inode->i_data;
188 }
189
190 fput(cfi->cfi_container);
191 kfree(coda_file->private_data);
192 coda_file->private_data = NULL;
193
194 unlock_kernel();
Jan Harkesd3fec422007-07-21 04:37:26 -0700195
196 /* VFS fput ignores the return value from file_operations->release, so
197 * there is no use returning an error here */
198 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199}
200
201int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
202{
203 struct file *host_file;
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100204 struct inode *coda_inode = coda_dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 struct coda_file_info *cfi;
206 int err = 0;
207
208 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
209 S_ISLNK(coda_inode->i_mode)))
210 return -EINVAL;
211
212 cfi = CODA_FTOC(coda_file);
213 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
214 host_file = cfi->cfi_container;
215
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100216 err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 if ( !err && !datasync ) {
218 lock_kernel();
219 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
220 unlock_kernel();
221 }
222
223 return err;
224}
225
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800226const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 .llseek = generic_file_llseek,
228 .read = coda_file_read,
229 .write = coda_file_write,
230 .mmap = coda_file_mmap,
231 .open = coda_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 .release = coda_release,
233 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200234 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235};
236