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1/*
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>
16#include <linux/cred.h>
17#include <linux/errno.h>
18#include <linux/spinlock.h>
19#include <linux/string.h>
20#include <linux/slab.h>
21#include <linux/uaccess.h>
22
23#include <linux/coda.h>
24#include <linux/coda_psdev.h>
25
26#include "coda_linux.h"
27#include "coda_int.h"
28
29static ssize_t
30coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
31{
32 struct file *coda_file = iocb->ki_filp;
33 struct coda_file_info *cfi = CODA_FTOC(coda_file);
34
35 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
36
37 return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
38}
39
40static ssize_t
41coda_file_splice_read(struct file *coda_file, loff_t *ppos,
42 struct pipe_inode_info *pipe, size_t count,
43 unsigned int flags)
44{
45 ssize_t (*splice_read)(struct file *, loff_t *,
46 struct pipe_inode_info *, size_t, unsigned int);
47 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
54 splice_read = host_file->f_op->splice_read;
55 if (!splice_read)
56 splice_read = default_file_splice_read;
57
58 return splice_read(host_file, ppos, pipe, count, flags);
59}
60
61static ssize_t
62coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
63{
64 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);
67 struct file *host_file;
68 ssize_t ret;
69
70 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
71
72 host_file = cfi->cfi_container;
73 file_start_write(host_file);
74 inode_lock(coda_inode);
75 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
76 coda_inode->i_size = file_inode(host_file)->i_size;
77 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
78 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
79 inode_unlock(coda_inode);
80 file_end_write(host_file);
81 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
96 if (!host_file->f_op->mmap)
97 return -ENODEV;
98
99 coda_inode = file_inode(coda_file);
100 host_inode = file_inode(host_file);
101
102 cii = ITOC(coda_inode);
103 spin_lock(&cii->c_lock);
104 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! */
110 else if (coda_inode->i_mapping != host_inode->i_mapping) {
111 spin_unlock(&cii->c_lock);
112 return -EBUSY;
113 }
114
115 /* keep track of how often the coda_inode/host_file has been mmapped */
116 cii->c_mapcount++;
117 cfi->cfi_mapcount++;
118 spin_unlock(&cii->c_lock);
119
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
131 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
132 if (!cfi)
133 return -ENOMEM;
134
135 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
136 &host_file);
137 if (!host_file)
138 error = -EIO;
139
140 if (error) {
141 kfree(cfi);
142 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;
153 return 0;
154}
155
156int 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;
163 int err;
164
165 cfi = CODA_FTOC(coda_file);
166 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
167
168 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
169 coda_flags, coda_file->f_cred->fsuid);
170
171 host_inode = file_inode(cfi->cfi_container);
172 cii = ITOC(coda_inode);
173
174 /* did we mmap this file? */
175 spin_lock(&cii->c_lock);
176 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 }
181 spin_unlock(&cii->c_lock);
182
183 fput(cfi->cfi_container);
184 kfree(coda_file->private_data);
185 coda_file->private_data = NULL;
186
187 /* VFS fput ignores the return value from file_operations->release, so
188 * there is no use returning an error here */
189 return 0;
190}
191
192int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
193{
194 struct file *host_file;
195 struct inode *coda_inode = file_inode(coda_file);
196 struct coda_file_info *cfi;
197 int err;
198
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
203 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
204 if (err)
205 return err;
206 inode_lock(coda_inode);
207
208 cfi = CODA_FTOC(coda_file);
209 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
210 host_file = cfi->cfi_container;
211
212 err = vfs_fsync(host_file, datasync);
213 if (!err && !datasync)
214 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
215 inode_unlock(coda_inode);
216
217 return err;
218}
219
220const struct file_operations coda_file_operations = {
221 .llseek = generic_file_llseek,
222 .read_iter = coda_file_read_iter,
223 .write_iter = coda_file_write_iter,
224 .mmap = coda_file_mmap,
225 .open = coda_open,
226 .release = coda_release,
227 .fsync = coda_fsync,
228 .splice_read = coda_file_splice_read,
229};
230
1/*
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>
16#include <linux/cred.h>
17#include <linux/errno.h>
18#include <linux/spinlock.h>
19#include <linux/string.h>
20#include <linux/slab.h>
21#include <asm/uaccess.h>
22
23#include <linux/coda.h>
24#include <linux/coda_psdev.h>
25
26#include "coda_linux.h"
27#include "coda_int.h"
28
29static 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->read)
40 return -EINVAL;
41
42 return host_file->f_op->read(host_file, buf, count, ppos);
43}
44
45static ssize_t
46coda_file_splice_read(struct file *coda_file, loff_t *ppos,
47 struct pipe_inode_info *pipe, size_t count,
48 unsigned int flags)
49{
50 ssize_t (*splice_read)(struct file *, loff_t *,
51 struct pipe_inode_info *, size_t, unsigned int);
52 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
59 splice_read = host_file->f_op->splice_read;
60 if (!splice_read)
61 splice_read = default_file_splice_read;
62
63 return splice_read(host_file, ppos, pipe, count, flags);
64}
65
66static ssize_t
67coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
68{
69 struct inode *host_inode, *coda_inode = file_inode(coda_file);
70 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->write)
79 return -EINVAL;
80
81 host_inode = file_inode(host_file);
82 file_start_write(host_file);
83 mutex_lock(&coda_inode->i_mutex);
84
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;
90 mutex_unlock(&coda_inode->i_mutex);
91 file_end_write(host_file);
92
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
108 if (!host_file->f_op->mmap)
109 return -ENODEV;
110
111 coda_inode = file_inode(coda_file);
112 host_inode = file_inode(host_file);
113
114 cii = ITOC(coda_inode);
115 spin_lock(&cii->c_lock);
116 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! */
122 else if (coda_inode->i_mapping != host_inode->i_mapping) {
123 spin_unlock(&cii->c_lock);
124 return -EBUSY;
125 }
126
127 /* keep track of how often the coda_inode/host_file has been mmapped */
128 cii->c_mapcount++;
129 cfi->cfi_mapcount++;
130 spin_unlock(&cii->c_lock);
131
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
143 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
144 if (!cfi)
145 return -ENOMEM;
146
147 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
148 &host_file);
149 if (!host_file)
150 error = -EIO;
151
152 if (error) {
153 kfree(cfi);
154 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;
165 return 0;
166}
167
168int 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;
175 int err;
176
177 cfi = CODA_FTOC(coda_file);
178 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
179
180 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
181 coda_flags, coda_file->f_cred->fsuid);
182
183 host_inode = file_inode(cfi->cfi_container);
184 cii = ITOC(coda_inode);
185
186 /* did we mmap this file? */
187 spin_lock(&cii->c_lock);
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 spin_unlock(&cii->c_lock);
194
195 fput(cfi->cfi_container);
196 kfree(coda_file->private_data);
197 coda_file->private_data = NULL;
198
199 /* VFS fput ignores the return value from file_operations->release, so
200 * there is no use returning an error here */
201 return 0;
202}
203
204int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
205{
206 struct file *host_file;
207 struct inode *coda_inode = file_inode(coda_file);
208 struct coda_file_info *cfi;
209 int err;
210
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
215 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
220 cfi = CODA_FTOC(coda_file);
221 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
222 host_file = cfi->cfi_container;
223
224 err = vfs_fsync(host_file, datasync);
225 if (!err && !datasync)
226 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
227 mutex_unlock(&coda_inode->i_mutex);
228
229 return err;
230}
231
232const struct file_operations coda_file_operations = {
233 .llseek = generic_file_llseek,
234 .read = coda_file_read,
235 .write = coda_file_write,
236 .mmap = coda_file_mmap,
237 .open = coda_open,
238 .release = coda_release,
239 .fsync = coda_fsync,
240 .splice_read = coda_file_splice_read,
241};
242