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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>
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -040018#include <linux/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/string.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <asm/uaccess.h>
22
23#include <linux/coda.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/coda_psdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Al Viro31a203d2011-01-12 16:36:09 -050026#include "coda_linux.h"
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{
Miklos Szeredi68181732009-05-07 15:37:36 +020050 ssize_t (*splice_read)(struct file *, loff_t *,
51 struct pipe_inode_info *, size_t, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 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
Miklos Szeredi68181732009-05-07 15:37:36 +020059 splice_read = host_file->f_op->splice_read;
60 if (!splice_read)
61 splice_read = default_file_splice_read;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Miklos Szeredi68181732009-05-07 15:37:36 +020063 return splice_read(host_file, ppos, pipe, count, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064}
65
66static ssize_t
67coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
68{
Josef Sipekd4176d32006-12-08 02:36:56 -080069 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 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
Josef Sipekd4176d32006-12-08 02:36:56 -080081 host_inode = host_file->f_path.dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080082 mutex_lock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
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;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080089 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
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
Josef Sipekd4176d32006-12-08 02:36:56 -0800109 coda_inode = coda_file->f_path.dentry->d_inode;
110 host_inode = host_file->f_path.dentry->d_inode;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400111
112 cii = ITOC(coda_inode);
113 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 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! */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400120 else if (coda_inode->i_mapping != host_inode->i_mapping) {
121 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return -EBUSY;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400123 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 /* keep track of how often the coda_inode/host_file has been mmapped */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 cii->c_mapcount++;
127 cfi->cfi_mapcount++;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400128 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700142 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
Jan Harkes38c2e432007-07-19 01:48:41 -0700146 &host_file);
147 if (!host_file)
148 error = -EIO;
149
150 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 kfree(cfi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 return 0;
164}
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166int 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;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400173 int err;
Jan Harkes3cf01f22007-07-19 01:48:51 -0700174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 cfi = CODA_FTOC(coda_file);
176 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
177
Jan Harkesd3fec422007-07-21 04:37:26 -0700178 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
David Howellsd76b0d92008-11-14 10:39:25 +1100179 coda_flags, coda_file->f_cred->fsuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Josef Sipekd4176d32006-12-08 02:36:56 -0800181 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 cii = ITOC(coda_inode);
183
184 /* did we mmap this file? */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400185 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 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 }
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400191 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 fput(cfi->cfi_container);
194 kfree(coda_file->private_data);
195 coda_file->private_data = NULL;
196
Jan Harkesd3fec422007-07-21 04:37:26 -0700197 /* VFS fput ignores the return value from file_operations->release, so
198 * there is no use returning an error here */
199 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200}
201
Christoph Hellwig7ea80852010-05-26 17:53:25 +0200202int coda_fsync(struct file *coda_file, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
204 struct file *host_file;
Christoph Hellwig7ea80852010-05-26 17:53:25 +0200205 struct inode *coda_inode = coda_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 struct coda_file_info *cfi;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400207 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
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 cfi = CODA_FTOC(coda_file);
214 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
215 host_file = cfi->cfi_container;
216
Christoph Hellwig8018ab02010-03-22 17:32:25 +0100217 err = vfs_fsync(host_file, datasync);
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400218 if (!err && !datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 return err;
222}
223
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800224const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 .llseek = generic_file_llseek,
226 .read = coda_file_read,
227 .write = coda_file_write,
228 .mmap = coda_file_mmap,
229 .open = coda_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 .release = coda_release,
231 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200232 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233};
234