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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>
Fabian Frederick834b46c2014-08-08 14:20:33 -070021#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
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
Al Viro72c2d532013-09-22 16:27:52 -040039 if (!host_file->f_op->read)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 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{
Al Viro496ad9a2013-01-23 17:07:38 -050069 struct inode *host_inode, *coda_inode = file_inode(coda_file);
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
Al Viro72c2d532013-09-22 16:27:52 -040078 if (!host_file->f_op->write)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 return -EINVAL;
80
Al Viro496ad9a2013-01-23 17:07:38 -050081 host_inode = file_inode(host_file);
Al Viro03d95eb2013-03-20 13:04:20 -040082 file_start_write(host_file);
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);
Al Viro03d95eb2013-03-20 13:04:20 -040091 file_end_write(host_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
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
Al Viro72c2d532013-09-22 16:27:52 -0400108 if (!host_file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 return -ENODEV;
110
Al Viro496ad9a2013-01-23 17:07:38 -0500111 coda_inode = file_inode(coda_file);
112 host_inode = file_inode(host_file);
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400113
114 cii = ITOC(coda_inode);
115 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 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! */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400122 else if (coda_inode->i_mapping != host_inode->i_mapping) {
123 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 return -EBUSY;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400125 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 /* keep track of how often the coda_inode/host_file has been mmapped */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 cii->c_mapcount++;
129 cfi->cfi_mapcount++;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400130 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700144 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
Jan Harkes38c2e432007-07-19 01:48:41 -0700148 &host_file);
149 if (!host_file)
150 error = -EIO;
151
152 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 kfree(cfi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 return 0;
166}
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168int 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;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400175 int err;
Jan Harkes3cf01f22007-07-19 01:48:51 -0700176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 cfi = CODA_FTOC(coda_file);
178 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
179
Jan Harkesd3fec422007-07-21 04:37:26 -0700180 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
David Howellsd76b0d92008-11-14 10:39:25 +1100181 coda_flags, coda_file->f_cred->fsuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Al Viro496ad9a2013-01-23 17:07:38 -0500183 host_inode = file_inode(cfi->cfi_container);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 cii = ITOC(coda_inode);
185
186 /* did we mmap this file? */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400187 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 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 }
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400193 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
195 fput(cfi->cfi_container);
196 kfree(coda_file->private_data);
197 coda_file->private_data = NULL;
198
Jan Harkesd3fec422007-07-21 04:37:26 -0700199 /* VFS fput ignores the return value from file_operations->release, so
200 * there is no use returning an error here */
201 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202}
203
Josef Bacik02c24a82011-07-16 20:44:56 -0400204int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
206 struct file *host_file;
Al Viro496ad9a2013-01-23 17:07:38 -0500207 struct inode *coda_inode = file_inode(coda_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 struct coda_file_info *cfi;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400209 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
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
Josef Bacik02c24a82011-07-16 20:44:56 -0400215 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 cfi = CODA_FTOC(coda_file);
221 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
222 host_file = cfi->cfi_container;
223
Christoph Hellwig8018ab02010-03-22 17:32:25 +0100224 err = vfs_fsync(host_file, datasync);
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400225 if (!err && !datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
Josef Bacik02c24a82011-07-16 20:44:56 -0400227 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 return err;
230}
231
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800232const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 .llseek = generic_file_llseek,
234 .read = coda_file_read,
235 .write = coda_file_write,
236 .mmap = coda_file_mmap,
237 .open = coda_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 .release = coda_release,
239 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200240 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241};
242