coda: check for async upcall request using local state
[linux-block.git] / fs / coda / file.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT
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>
7596b27d 17#include <linux/cred.h>
1da177e4 18#include <linux/errno.h>
b5ce1d83 19#include <linux/spinlock.h>
1da177e4 20#include <linux/string.h>
5a0e3ad6 21#include <linux/slab.h>
834b46c3 22#include <linux/uaccess.h>
a9fba24c 23#include <linux/uio.h>
1da177e4
LT
24
25#include <linux/coda.h>
8fc8b9df 26#include "coda_psdev.h"
31a203df 27#include "coda_linux.h"
c98d8cfb
AB
28#include "coda_int.h"
29
7fa0a1da
JH
30struct coda_vm_ops {
31 atomic_t refcnt;
32 struct file *coda_file;
33 const struct vm_operations_struct *host_vm_ops;
34 struct vm_operations_struct vm_ops;
35};
36
1da177e4 37static ssize_t
c12c49e7 38coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
1da177e4 39{
c12c49e7 40 struct file *coda_file = iocb->ki_filp;
a9fba24c 41 struct inode *coda_inode = file_inode(coda_file);
5bb44810 42 struct coda_file_info *cfi = coda_ftoc(coda_file);
a9fba24c
PC
43 loff_t ki_pos = iocb->ki_pos;
44 size_t count = iov_iter_count(to);
45 ssize_t ret;
46
47 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
48 &cfi->cfi_access_intent,
49 count, ki_pos, CODA_ACCESS_TYPE_READ);
50 if (ret)
51 goto finish_read;
52
53 ret = vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0);
1da177e4 54
a9fba24c
PC
55finish_read:
56 venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
57 &cfi->cfi_access_intent,
58 count, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
59 return ret;
1da177e4
LT
60}
61
1da177e4 62static ssize_t
c12c49e7 63coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
1da177e4 64{
c12c49e7
AV
65 struct file *coda_file = iocb->ki_filp;
66 struct inode *coda_inode = file_inode(coda_file);
5bb44810 67 struct coda_file_info *cfi = coda_ftoc(coda_file);
a9fba24c
PC
68 struct file *host_file = cfi->cfi_container;
69 loff_t ki_pos = iocb->ki_pos;
70 size_t count = iov_iter_count(to);
1da177e4
LT
71 ssize_t ret;
72
a9fba24c
PC
73 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
74 &cfi->cfi_access_intent,
75 count, ki_pos, CODA_ACCESS_TYPE_WRITE);
76 if (ret)
77 goto finish_write;
78
03d95eb2 79 file_start_write(host_file);
5955102c 80 inode_lock(coda_inode);
abbb6589 81 ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0);
c12c49e7 82 coda_inode->i_size = file_inode(host_file)->i_size;
1da177e4 83 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
02027d42 84 coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode);
5955102c 85 inode_unlock(coda_inode);
03d95eb2 86 file_end_write(host_file);
a9fba24c
PC
87
88finish_write:
89 venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
90 &cfi->cfi_access_intent,
91 count, ki_pos, CODA_ACCESS_TYPE_WRITE_FINISH);
1da177e4
LT
92 return ret;
93}
94
7fa0a1da
JH
95static void
96coda_vm_open(struct vm_area_struct *vma)
97{
98 struct coda_vm_ops *cvm_ops =
99 container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
100
101 atomic_inc(&cvm_ops->refcnt);
102
103 if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open)
104 cvm_ops->host_vm_ops->open(vma);
105}
106
107static void
108coda_vm_close(struct vm_area_struct *vma)
109{
110 struct coda_vm_ops *cvm_ops =
111 container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
112
113 if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close)
114 cvm_ops->host_vm_ops->close(vma);
115
116 if (atomic_dec_and_test(&cvm_ops->refcnt)) {
117 vma->vm_ops = cvm_ops->host_vm_ops;
118 fput(cvm_ops->coda_file);
119 kfree(cvm_ops);
120 }
121}
122
1da177e4
LT
123static int
124coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
125{
a9fba24c
PC
126 struct inode *coda_inode = file_inode(coda_file);
127 struct coda_file_info *cfi = coda_ftoc(coda_file);
128 struct file *host_file = cfi->cfi_container;
129 struct inode *host_inode = file_inode(host_file);
1da177e4 130 struct coda_inode_info *cii;
7fa0a1da 131 struct coda_vm_ops *cvm_ops;
a9fba24c
PC
132 loff_t ppos;
133 size_t count;
7fa0a1da 134 int ret;
1da177e4 135
72c2d531 136 if (!host_file->f_op->mmap)
1da177e4
LT
137 return -ENODEV;
138
7fa0a1da
JH
139 if (WARN_ON(coda_file != vma->vm_file))
140 return -EIO;
141
a9fba24c
PC
142 count = vma->vm_end - vma->vm_start;
143 ppos = vma->vm_pgoff * PAGE_SIZE;
144
145 ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
146 &cfi->cfi_access_intent,
147 count, ppos, CODA_ACCESS_TYPE_MMAP);
148 if (ret)
149 return ret;
150
7fa0a1da
JH
151 cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL);
152 if (!cvm_ops)
153 return -ENOMEM;
154
b5ce1d83
YA
155 cii = ITOC(coda_inode);
156 spin_lock(&cii->c_lock);
1da177e4
LT
157 coda_file->f_mapping = host_file->f_mapping;
158 if (coda_inode->i_mapping == &coda_inode->i_data)
159 coda_inode->i_mapping = host_inode->i_mapping;
160
161 /* only allow additional mmaps as long as userspace isn't changing
162 * the container file on us! */
b5ce1d83
YA
163 else if (coda_inode->i_mapping != host_inode->i_mapping) {
164 spin_unlock(&cii->c_lock);
7fa0a1da 165 kfree(cvm_ops);
1da177e4 166 return -EBUSY;
b5ce1d83 167 }
1da177e4
LT
168
169 /* keep track of how often the coda_inode/host_file has been mmapped */
1da177e4
LT
170 cii->c_mapcount++;
171 cfi->cfi_mapcount++;
b5ce1d83 172 spin_unlock(&cii->c_lock);
1da177e4 173
7fa0a1da
JH
174 vma->vm_file = get_file(host_file);
175 ret = call_mmap(vma->vm_file, vma);
176
177 if (ret) {
9da29c7f
CK
178 /* if call_mmap fails, our caller will put host_file so we
179 * should drop the reference to the coda_file that we got.
7fa0a1da 180 */
9da29c7f 181 fput(coda_file);
7fa0a1da
JH
182 kfree(cvm_ops);
183 } else {
184 /* here we add redirects for the open/close vm_operations */
185 cvm_ops->host_vm_ops = vma->vm_ops;
186 if (vma->vm_ops)
187 cvm_ops->vm_ops = *vma->vm_ops;
188
189 cvm_ops->vm_ops.open = coda_vm_open;
190 cvm_ops->vm_ops.close = coda_vm_close;
191 cvm_ops->coda_file = coda_file;
192 atomic_set(&cvm_ops->refcnt, 1);
193
194 vma->vm_ops = &cvm_ops->vm_ops;
195 }
196 return ret;
1da177e4
LT
197}
198
199int coda_open(struct inode *coda_inode, struct file *coda_file)
200{
201 struct file *host_file = NULL;
202 int error;
203 unsigned short flags = coda_file->f_flags & (~O_EXCL);
204 unsigned short coda_flags = coda_flags_to_cflags(flags);
205 struct coda_file_info *cfi;
206
1da177e4 207 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1 208 if (!cfi)
1da177e4 209 return -ENOMEM;
1da177e4 210
1da177e4 211 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437
JH
212 &host_file);
213 if (!host_file)
214 error = -EIO;
215
216 if (error) {
1da177e4 217 kfree(cfi);
1da177e4
LT
218 return error;
219 }
220
221 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
222
223 cfi->cfi_magic = CODA_MAGIC;
224 cfi->cfi_mapcount = 0;
225 cfi->cfi_container = host_file;
a9fba24c
PC
226 /* assume access intents are supported unless we hear otherwise */
227 cfi->cfi_access_intent = true;
1da177e4
LT
228
229 BUG_ON(coda_file->private_data != NULL);
230 coda_file->private_data = cfi;
1da177e4
LT
231 return 0;
232}
233
1da177e4
LT
234int coda_release(struct inode *coda_inode, struct file *coda_file)
235{
236 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
237 unsigned short coda_flags = coda_flags_to_cflags(flags);
238 struct coda_file_info *cfi;
239 struct coda_inode_info *cii;
240 struct inode *host_inode;
f7cc02b8 241 int err;
3cf01f28 242
5bb44810 243 cfi = coda_ftoc(coda_file);
1da177e4 244
d3fec424 245 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b 246 coda_flags, coda_file->f_cred->fsuid);
1da177e4 247
496ad9aa 248 host_inode = file_inode(cfi->cfi_container);
1da177e4
LT
249 cii = ITOC(coda_inode);
250
251 /* did we mmap this file? */
b5ce1d83 252 spin_lock(&cii->c_lock);
1da177e4
LT
253 if (coda_inode->i_mapping == &host_inode->i_data) {
254 cii->c_mapcount -= cfi->cfi_mapcount;
255 if (!cii->c_mapcount)
256 coda_inode->i_mapping = &coda_inode->i_data;
257 }
b5ce1d83 258 spin_unlock(&cii->c_lock);
1da177e4
LT
259
260 fput(cfi->cfi_container);
261 kfree(coda_file->private_data);
262 coda_file->private_data = NULL;
263
d3fec424
JH
264 /* VFS fput ignores the return value from file_operations->release, so
265 * there is no use returning an error here */
266 return 0;
1da177e4
LT
267}
268
02c24a82 269int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
1da177e4
LT
270{
271 struct file *host_file;
496ad9aa 272 struct inode *coda_inode = file_inode(coda_file);
1da177e4 273 struct coda_file_info *cfi;
f7cc02b8 274 int err;
1da177e4
LT
275
276 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
277 S_ISLNK(coda_inode->i_mode)))
278 return -EINVAL;
279
02c24a82
JB
280 err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
281 if (err)
282 return err;
5955102c 283 inode_lock(coda_inode);
02c24a82 284
5bb44810 285 cfi = coda_ftoc(coda_file);
1da177e4
LT
286 host_file = cfi->cfi_container;
287
8018ab05 288 err = vfs_fsync(host_file, datasync);
f7cc02b8 289 if (!err && !datasync)
1da177e4 290 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
5955102c 291 inode_unlock(coda_inode);
1da177e4
LT
292
293 return err;
294}
295
4b6f5d20 296const struct file_operations coda_file_operations = {
1da177e4 297 .llseek = generic_file_llseek,
c12c49e7
AV
298 .read_iter = coda_file_read_iter,
299 .write_iter = coda_file_write_iter,
1da177e4
LT
300 .mmap = coda_file_mmap,
301 .open = coda_open,
1da177e4
LT
302 .release = coda_release,
303 .fsync = coda_fsync,
82c156f8 304 .splice_read = generic_file_splice_read,
1da177e4 305};