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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
Al Viroc12c49e2015-04-03 10:58:11 -040030coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031{
Al Viroc12c49e2015-04-03 10:58:11 -040032 struct file *coda_file = iocb->ki_filp;
33 struct coda_file_info *cfi = CODA_FTOC(coda_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Al Viroc12c49e2015-04-03 10:58:11 -040037 return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038}
39
40static ssize_t
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020041coda_file_splice_read(struct file *coda_file, loff_t *ppos,
42 struct pipe_inode_info *pipe, size_t count,
43 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Miklos Szeredi68181732009-05-07 15:37:36 +020045 ssize_t (*splice_read)(struct file *, loff_t *,
46 struct pipe_inode_info *, size_t, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 struct coda_file_info *cfi;
48 struct file *host_file;
49
50 cfi = CODA_FTOC(coda_file);
51 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
52 host_file = cfi->cfi_container;
53
Miklos Szeredi68181732009-05-07 15:37:36 +020054 splice_read = host_file->f_op->splice_read;
55 if (!splice_read)
56 splice_read = default_file_splice_read;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Miklos Szeredi68181732009-05-07 15:37:36 +020058 return splice_read(host_file, ppos, pipe, count, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059}
60
61static ssize_t
Al Viroc12c49e2015-04-03 10:58:11 -040062coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
Al Viroc12c49e2015-04-03 10:58:11 -040064 struct file *coda_file = iocb->ki_filp;
65 struct inode *coda_inode = file_inode(coda_file);
66 struct coda_file_info *cfi = CODA_FTOC(coda_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 struct file *host_file;
68 ssize_t ret;
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
Al Viroc12c49e2015-04-03 10:58:11 -040071
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 host_file = cfi->cfi_container;
Al Viro03d95eb2013-03-20 13:04:20 -040073 file_start_write(host_file);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080074 mutex_lock(&coda_inode->i_mutex);
Al Viroc12c49e2015-04-03 10:58:11 -040075 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
76 coda_inode->i_size = file_inode(host_file)->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
78 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080079 mutex_unlock(&coda_inode->i_mutex);
Al Viro03d95eb2013-03-20 13:04:20 -040080 file_end_write(host_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 return ret;
82}
83
84static int
85coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
86{
87 struct coda_file_info *cfi;
88 struct coda_inode_info *cii;
89 struct file *host_file;
90 struct inode *coda_inode, *host_inode;
91
92 cfi = CODA_FTOC(coda_file);
93 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
94 host_file = cfi->cfi_container;
95
Al Viro72c2d532013-09-22 16:27:52 -040096 if (!host_file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 return -ENODEV;
98
Al Viro496ad9a2013-01-23 17:07:38 -050099 coda_inode = file_inode(coda_file);
100 host_inode = file_inode(host_file);
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400101
102 cii = ITOC(coda_inode);
103 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 coda_file->f_mapping = host_file->f_mapping;
105 if (coda_inode->i_mapping == &coda_inode->i_data)
106 coda_inode->i_mapping = host_inode->i_mapping;
107
108 /* only allow additional mmaps as long as userspace isn't changing
109 * the container file on us! */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400110 else if (coda_inode->i_mapping != host_inode->i_mapping) {
111 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return -EBUSY;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400113 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 /* keep track of how often the coda_inode/host_file has been mmapped */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 cii->c_mapcount++;
117 cfi->cfi_mapcount++;
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400118 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120 return host_file->f_op->mmap(host_file, vma);
121}
122
123int coda_open(struct inode *coda_inode, struct file *coda_file)
124{
125 struct file *host_file = NULL;
126 int error;
127 unsigned short flags = coda_file->f_flags & (~O_EXCL);
128 unsigned short coda_flags = coda_flags_to_cflags(flags);
129 struct coda_file_info *cfi;
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700132 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
Jan Harkes38c2e432007-07-19 01:48:41 -0700136 &host_file);
137 if (!host_file)
138 error = -EIO;
139
140 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 kfree(cfi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 return error;
143 }
144
145 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
146
147 cfi->cfi_magic = CODA_MAGIC;
148 cfi->cfi_mapcount = 0;
149 cfi->cfi_container = host_file;
150
151 BUG_ON(coda_file->private_data != NULL);
152 coda_file->private_data = cfi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 return 0;
154}
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156int coda_release(struct inode *coda_inode, struct file *coda_file)
157{
158 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
159 unsigned short coda_flags = coda_flags_to_cflags(flags);
160 struct coda_file_info *cfi;
161 struct coda_inode_info *cii;
162 struct inode *host_inode;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400163 int err;
Jan Harkes3cf01f22007-07-19 01:48:51 -0700164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 cfi = CODA_FTOC(coda_file);
166 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
167
Jan Harkesd3fec422007-07-21 04:37:26 -0700168 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
David Howellsd76b0d92008-11-14 10:39:25 +1100169 coda_flags, coda_file->f_cred->fsuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Al Viro496ad9a2013-01-23 17:07:38 -0500171 host_inode = file_inode(cfi->cfi_container);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 cii = ITOC(coda_inode);
173
174 /* did we mmap this file? */
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400175 spin_lock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 if (coda_inode->i_mapping == &host_inode->i_data) {
177 cii->c_mapcount -= cfi->cfi_mapcount;
178 if (!cii->c_mapcount)
179 coda_inode->i_mapping = &coda_inode->i_data;
180 }
Yoshihisa Abeb5ce1d82010-10-25 02:03:44 -0400181 spin_unlock(&cii->c_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 fput(cfi->cfi_container);
184 kfree(coda_file->private_data);
185 coda_file->private_data = NULL;
186
Jan Harkesd3fec422007-07-21 04:37:26 -0700187 /* VFS fput ignores the return value from file_operations->release, so
188 * there is no use returning an error here */
189 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
191
Josef Bacik02c24a82011-07-16 20:44:56 -0400192int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
194 struct file *host_file;
Al Viro496ad9a2013-01-23 17:07:38 -0500195 struct inode *coda_inode = file_inode(coda_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 struct coda_file_info *cfi;
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400197 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
200 S_ISLNK(coda_inode->i_mode)))
201 return -EINVAL;
202
Josef Bacik02c24a82011-07-16 20:44:56 -0400203 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
204 if (err)
205 return err;
206 mutex_lock(&coda_inode->i_mutex);
207
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 cfi = CODA_FTOC(coda_file);
209 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
210 host_file = cfi->cfi_container;
211
Christoph Hellwig8018ab02010-03-22 17:32:25 +0100212 err = vfs_fsync(host_file, datasync);
Yoshihisa Abef7cc02b82010-10-25 02:03:45 -0400213 if (!err && !datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
Josef Bacik02c24a82011-07-16 20:44:56 -0400215 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217 return err;
218}
219
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800220const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 .llseek = generic_file_llseek,
Al Viroc12c49e2015-04-03 10:58:11 -0400222 .read_iter = coda_file_read_iter,
223 .write_iter = coda_file_write_iter,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 .mmap = coda_file_mmap,
225 .open = coda_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 .release = coda_release,
227 .fsync = coda_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +0200228 .splice_read = coda_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229};
230