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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * File operations for Coda.
4 * Original version: (C) 1996 Peter Braam
5 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
6 *
7 * Carnegie Mellon encourages users of this code to contribute improvements
8 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
9 */
10
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/time.h>
14#include <linux/file.h>
15#include <linux/fs.h>
16#include <linux/stat.h>
17#include <linux/cred.h>
18#include <linux/errno.h>
19#include <linux/spinlock.h>
20#include <linux/string.h>
21#include <linux/slab.h>
22#include <linux/uaccess.h>
23
24#include <linux/coda.h>
25#include <linux/coda_psdev.h>
26
27#include "coda_linux.h"
28#include "coda_int.h"
29
30static ssize_t
31coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
32{
33 struct file *coda_file = iocb->ki_filp;
34 struct coda_file_info *cfi = CODA_FTOC(coda_file);
35
36 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
37
38 return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0);
39}
40
41static ssize_t
42coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
43{
44 struct file *coda_file = iocb->ki_filp;
45 struct inode *coda_inode = file_inode(coda_file);
46 struct coda_file_info *cfi = CODA_FTOC(coda_file);
47 struct file *host_file;
48 ssize_t ret;
49
50 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
51
52 host_file = cfi->cfi_container;
53 file_start_write(host_file);
54 inode_lock(coda_inode);
55 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0);
56 coda_inode->i_size = file_inode(host_file)->i_size;
57 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
58 coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode);
59 inode_unlock(coda_inode);
60 file_end_write(host_file);
61 return ret;
62}
63
64static int
65coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
66{
67 struct coda_file_info *cfi;
68 struct coda_inode_info *cii;
69 struct file *host_file;
70 struct inode *coda_inode, *host_inode;
71
72 cfi = CODA_FTOC(coda_file);
73 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
74 host_file = cfi->cfi_container;
75
76 if (!host_file->f_op->mmap)
77 return -ENODEV;
78
79 coda_inode = file_inode(coda_file);
80 host_inode = file_inode(host_file);
81
82 cii = ITOC(coda_inode);
83 spin_lock(&cii->c_lock);
84 coda_file->f_mapping = host_file->f_mapping;
85 if (coda_inode->i_mapping == &coda_inode->i_data)
86 coda_inode->i_mapping = host_inode->i_mapping;
87
88 /* only allow additional mmaps as long as userspace isn't changing
89 * the container file on us! */
90 else if (coda_inode->i_mapping != host_inode->i_mapping) {
91 spin_unlock(&cii->c_lock);
92 return -EBUSY;
93 }
94
95 /* keep track of how often the coda_inode/host_file has been mmapped */
96 cii->c_mapcount++;
97 cfi->cfi_mapcount++;
98 spin_unlock(&cii->c_lock);
99
100 return call_mmap(host_file, vma);
101}
102
103int coda_open(struct inode *coda_inode, struct file *coda_file)
104{
105 struct file *host_file = NULL;
106 int error;
107 unsigned short flags = coda_file->f_flags & (~O_EXCL);
108 unsigned short coda_flags = coda_flags_to_cflags(flags);
109 struct coda_file_info *cfi;
110
111 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
112 if (!cfi)
113 return -ENOMEM;
114
115 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
116 &host_file);
117 if (!host_file)
118 error = -EIO;
119
120 if (error) {
121 kfree(cfi);
122 return error;
123 }
124
125 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
126
127 cfi->cfi_magic = CODA_MAGIC;
128 cfi->cfi_mapcount = 0;
129 cfi->cfi_container = host_file;
130
131 BUG_ON(coda_file->private_data != NULL);
132 coda_file->private_data = cfi;
133 return 0;
134}
135
136int coda_release(struct inode *coda_inode, struct file *coda_file)
137{
138 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
139 unsigned short coda_flags = coda_flags_to_cflags(flags);
140 struct coda_file_info *cfi;
141 struct coda_inode_info *cii;
142 struct inode *host_inode;
143 int err;
144
145 cfi = CODA_FTOC(coda_file);
146 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
147
148 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
149 coda_flags, coda_file->f_cred->fsuid);
150
151 host_inode = file_inode(cfi->cfi_container);
152 cii = ITOC(coda_inode);
153
154 /* did we mmap this file? */
155 spin_lock(&cii->c_lock);
156 if (coda_inode->i_mapping == &host_inode->i_data) {
157 cii->c_mapcount -= cfi->cfi_mapcount;
158 if (!cii->c_mapcount)
159 coda_inode->i_mapping = &coda_inode->i_data;
160 }
161 spin_unlock(&cii->c_lock);
162
163 fput(cfi->cfi_container);
164 kfree(coda_file->private_data);
165 coda_file->private_data = NULL;
166
167 /* VFS fput ignores the return value from file_operations->release, so
168 * there is no use returning an error here */
169 return 0;
170}
171
172int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
173{
174 struct file *host_file;
175 struct inode *coda_inode = file_inode(coda_file);
176 struct coda_file_info *cfi;
177 int err;
178
179 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
180 S_ISLNK(coda_inode->i_mode)))
181 return -EINVAL;
182
183 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
184 if (err)
185 return err;
186 inode_lock(coda_inode);
187
188 cfi = CODA_FTOC(coda_file);
189 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
190 host_file = cfi->cfi_container;
191
192 err = vfs_fsync(host_file, datasync);
193 if (!err && !datasync)
194 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
195 inode_unlock(coda_inode);
196
197 return err;
198}
199
200const struct file_operations coda_file_operations = {
201 .llseek = generic_file_llseek,
202 .read_iter = coda_file_read_iter,
203 .write_iter = coda_file_write_iter,
204 .mmap = coda_file_mmap,
205 .open = coda_open,
206 .release = coda_release,
207 .fsync = coda_fsync,
208 .splice_read = generic_file_splice_read,
209};
210