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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>
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>
24#include <linux/coda_linux.h>
25#include <linux/coda_fs_i.h>
26#include <linux/coda_psdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080028#include "coda_int.h"
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030static ssize_t
31coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
32{
33 struct coda_file_info *cfi;
34 struct file *host_file;
35
36 cfi = CODA_FTOC(coda_file);
37 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
38 host_file = cfi->cfi_container;
39
40 if (!host_file->f_op || !host_file->f_op->read)
41 return -EINVAL;
42
43 return host_file->f_op->read(host_file, buf, count, ppos);
44}
45
46static ssize_t
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020047coda_file_splice_read(struct file *coda_file, loff_t *ppos,
48 struct pipe_inode_info *pipe, size_t count,
49 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
Miklos Szeredi68181732009-05-07 15:37:36 +020051 ssize_t (*splice_read)(struct file *, loff_t *,
52 struct pipe_inode_info *, size_t, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 struct coda_file_info *cfi;
54 struct file *host_file;
55
56 cfi = CODA_FTOC(coda_file);
57 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
58 host_file = cfi->cfi_container;
59
Miklos Szeredi68181732009-05-07 15:37:36 +020060 splice_read = host_file->f_op->splice_read;
61 if (!splice_read)
62 splice_read = default_file_splice_read;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Miklos Szeredi68181732009-05-07 15:37:36 +020064 return 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700138 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
141 lock_kernel();
142
143 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
Jan Harkes38c2e432007-07-19 01:48:41 -0700144 &host_file);
145 if (!host_file)
146 error = -EIO;
147
148 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 kfree(cfi);
150 unlock_kernel();
151 return error;
152 }
153
154 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
155
156 cfi->cfi_magic = CODA_MAGIC;
157 cfi->cfi_mapcount = 0;
158 cfi->cfi_container = host_file;
159
160 BUG_ON(coda_file->private_data != NULL);
161 coda_file->private_data = cfi;
162
163 unlock_kernel();
164 return 0;
165}
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167int coda_release(struct inode *coda_inode, struct file *coda_file)
168{
169 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
170 unsigned short coda_flags = coda_flags_to_cflags(flags);
171 struct coda_file_info *cfi;
172 struct coda_inode_info *cii;
173 struct inode *host_inode;
174 int err = 0;
175
176 lock_kernel();
Jan Harkes3cf01f22007-07-19 01:48:51 -0700177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 cfi = CODA_FTOC(coda_file);
179 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
180
Jan Harkesd3fec422007-07-21 04:37:26 -0700181 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
David Howellsd76b0d92008-11-14 10:39:25 +1100182 coda_flags, coda_file->f_cred->fsuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Josef Sipekd4176d32006-12-08 02:36:56 -0800184 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 cii = ITOC(coda_inode);
186
187 /* did we mmap this file? */
188 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 }
193
194 fput(cfi->cfi_container);
195 kfree(coda_file->private_data);
196 coda_file->private_data = NULL;
197
198 unlock_kernel();
Jan Harkesd3fec422007-07-21 04:37:26 -0700199
200 /* VFS fput ignores the return value from file_operations->release, so
201 * there is no use returning an error here */
202 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
205int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
206{
207 struct file *host_file;
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100208 struct inode *coda_inode = coda_dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 struct coda_file_info *cfi;
210 int err = 0;
211
212 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
213 S_ISLNK(coda_inode->i_mode)))
214 return -EINVAL;
215
216 cfi = CODA_FTOC(coda_file);
217 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
218 host_file = cfi->cfi_container;
219
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100220 err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 if ( !err && !datasync ) {
222 lock_kernel();
223 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
224 unlock_kernel();
225 }
226
227 return err;
228}
229
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800230const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 .llseek = generic_file_llseek,
232 .read = coda_file_read,
233 .write = coda_file_write,
234 .mmap = coda_file_mmap,
235 .open = coda_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 .release = coda_release,
237 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200238 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239};
240