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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 | ||
1077c285 | 11 | #include <linux/refcount.h> |
1da177e4 LT |
12 | #include <linux/types.h> |
13 | #include <linux/kernel.h> | |
14 | #include <linux/time.h> | |
15 | #include <linux/file.h> | |
16 | #include <linux/fs.h> | |
cbcc268b | 17 | #include <linux/pagemap.h> |
1da177e4 | 18 | #include <linux/stat.h> |
7596b27d | 19 | #include <linux/cred.h> |
1da177e4 | 20 | #include <linux/errno.h> |
b5ce1d83 | 21 | #include <linux/spinlock.h> |
1da177e4 | 22 | #include <linux/string.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
834b46c3 | 24 | #include <linux/uaccess.h> |
a9fba24c | 25 | #include <linux/uio.h> |
1da177e4 LT |
26 | |
27 | #include <linux/coda.h> | |
8fc8b9df | 28 | #include "coda_psdev.h" |
31a203df | 29 | #include "coda_linux.h" |
c98d8cfb AB |
30 | #include "coda_int.h" |
31 | ||
7fa0a1da | 32 | struct coda_vm_ops { |
1077c285 | 33 | refcount_t refcnt; |
7fa0a1da JH |
34 | struct file *coda_file; |
35 | const struct vm_operations_struct *host_vm_ops; | |
36 | struct vm_operations_struct vm_ops; | |
37 | }; | |
38 | ||
1da177e4 | 39 | static ssize_t |
c12c49e7 | 40 | coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 | 41 | { |
c12c49e7 | 42 | struct file *coda_file = iocb->ki_filp; |
a9fba24c | 43 | struct inode *coda_inode = file_inode(coda_file); |
5bb44810 | 44 | struct coda_file_info *cfi = coda_ftoc(coda_file); |
a9fba24c PC |
45 | loff_t ki_pos = iocb->ki_pos; |
46 | size_t count = iov_iter_count(to); | |
47 | ssize_t ret; | |
48 | ||
49 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
50 | &cfi->cfi_access_intent, | |
51 | count, ki_pos, CODA_ACCESS_TYPE_READ); | |
52 | if (ret) | |
53 | goto finish_read; | |
54 | ||
55 | ret = vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0); | |
1da177e4 | 56 | |
a9fba24c PC |
57 | finish_read: |
58 | venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
59 | &cfi->cfi_access_intent, | |
60 | count, ki_pos, CODA_ACCESS_TYPE_READ_FINISH); | |
61 | return ret; | |
1da177e4 LT |
62 | } |
63 | ||
1da177e4 | 64 | static ssize_t |
c12c49e7 | 65 | coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 | 66 | { |
c12c49e7 AV |
67 | struct file *coda_file = iocb->ki_filp; |
68 | struct inode *coda_inode = file_inode(coda_file); | |
5bb44810 | 69 | struct coda_file_info *cfi = coda_ftoc(coda_file); |
a9fba24c PC |
70 | struct file *host_file = cfi->cfi_container; |
71 | loff_t ki_pos = iocb->ki_pos; | |
72 | size_t count = iov_iter_count(to); | |
1da177e4 LT |
73 | ssize_t ret; |
74 | ||
a9fba24c PC |
75 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), |
76 | &cfi->cfi_access_intent, | |
77 | count, ki_pos, CODA_ACCESS_TYPE_WRITE); | |
78 | if (ret) | |
79 | goto finish_write; | |
80 | ||
03d95eb2 | 81 | file_start_write(host_file); |
5955102c | 82 | inode_lock(coda_inode); |
abbb6589 | 83 | ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0); |
c12c49e7 | 84 | coda_inode->i_size = file_inode(host_file)->i_size; |
1da177e4 | 85 | coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; |
02027d42 | 86 | coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode); |
5955102c | 87 | inode_unlock(coda_inode); |
03d95eb2 | 88 | file_end_write(host_file); |
a9fba24c PC |
89 | |
90 | finish_write: | |
91 | venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
92 | &cfi->cfi_access_intent, | |
93 | count, ki_pos, CODA_ACCESS_TYPE_WRITE_FINISH); | |
1da177e4 LT |
94 | return ret; |
95 | } | |
96 | ||
7fa0a1da JH |
97 | static void |
98 | coda_vm_open(struct vm_area_struct *vma) | |
99 | { | |
100 | struct coda_vm_ops *cvm_ops = | |
101 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); | |
102 | ||
1077c285 | 103 | refcount_inc(&cvm_ops->refcnt); |
7fa0a1da JH |
104 | |
105 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open) | |
106 | cvm_ops->host_vm_ops->open(vma); | |
107 | } | |
108 | ||
109 | static void | |
110 | coda_vm_close(struct vm_area_struct *vma) | |
111 | { | |
112 | struct coda_vm_ops *cvm_ops = | |
113 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); | |
114 | ||
115 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close) | |
116 | cvm_ops->host_vm_ops->close(vma); | |
117 | ||
1077c285 | 118 | if (refcount_dec_and_test(&cvm_ops->refcnt)) { |
7fa0a1da JH |
119 | vma->vm_ops = cvm_ops->host_vm_ops; |
120 | fput(cvm_ops->coda_file); | |
121 | kfree(cvm_ops); | |
122 | } | |
123 | } | |
124 | ||
1da177e4 LT |
125 | static int |
126 | coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) | |
127 | { | |
a9fba24c PC |
128 | struct inode *coda_inode = file_inode(coda_file); |
129 | struct coda_file_info *cfi = coda_ftoc(coda_file); | |
130 | struct file *host_file = cfi->cfi_container; | |
131 | struct inode *host_inode = file_inode(host_file); | |
1da177e4 | 132 | struct coda_inode_info *cii; |
7fa0a1da | 133 | struct coda_vm_ops *cvm_ops; |
a9fba24c PC |
134 | loff_t ppos; |
135 | size_t count; | |
7fa0a1da | 136 | int ret; |
1da177e4 | 137 | |
72c2d531 | 138 | if (!host_file->f_op->mmap) |
1da177e4 LT |
139 | return -ENODEV; |
140 | ||
7fa0a1da JH |
141 | if (WARN_ON(coda_file != vma->vm_file)) |
142 | return -EIO; | |
143 | ||
a9fba24c PC |
144 | count = vma->vm_end - vma->vm_start; |
145 | ppos = vma->vm_pgoff * PAGE_SIZE; | |
146 | ||
147 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
148 | &cfi->cfi_access_intent, | |
149 | count, ppos, CODA_ACCESS_TYPE_MMAP); | |
150 | if (ret) | |
151 | return ret; | |
152 | ||
7fa0a1da JH |
153 | cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL); |
154 | if (!cvm_ops) | |
155 | return -ENOMEM; | |
156 | ||
b5ce1d83 YA |
157 | cii = ITOC(coda_inode); |
158 | spin_lock(&cii->c_lock); | |
1da177e4 LT |
159 | coda_file->f_mapping = host_file->f_mapping; |
160 | if (coda_inode->i_mapping == &coda_inode->i_data) | |
161 | coda_inode->i_mapping = host_inode->i_mapping; | |
162 | ||
163 | /* only allow additional mmaps as long as userspace isn't changing | |
164 | * the container file on us! */ | |
b5ce1d83 YA |
165 | else if (coda_inode->i_mapping != host_inode->i_mapping) { |
166 | spin_unlock(&cii->c_lock); | |
7fa0a1da | 167 | kfree(cvm_ops); |
1da177e4 | 168 | return -EBUSY; |
b5ce1d83 | 169 | } |
1da177e4 LT |
170 | |
171 | /* keep track of how often the coda_inode/host_file has been mmapped */ | |
1da177e4 LT |
172 | cii->c_mapcount++; |
173 | cfi->cfi_mapcount++; | |
b5ce1d83 | 174 | spin_unlock(&cii->c_lock); |
1da177e4 | 175 | |
7fa0a1da JH |
176 | vma->vm_file = get_file(host_file); |
177 | ret = call_mmap(vma->vm_file, vma); | |
178 | ||
179 | if (ret) { | |
9da29c7f CK |
180 | /* if call_mmap fails, our caller will put host_file so we |
181 | * should drop the reference to the coda_file that we got. | |
7fa0a1da | 182 | */ |
9da29c7f | 183 | fput(coda_file); |
7fa0a1da JH |
184 | kfree(cvm_ops); |
185 | } else { | |
186 | /* here we add redirects for the open/close vm_operations */ | |
187 | cvm_ops->host_vm_ops = vma->vm_ops; | |
188 | if (vma->vm_ops) | |
189 | cvm_ops->vm_ops = *vma->vm_ops; | |
190 | ||
191 | cvm_ops->vm_ops.open = coda_vm_open; | |
192 | cvm_ops->vm_ops.close = coda_vm_close; | |
193 | cvm_ops->coda_file = coda_file; | |
1077c285 | 194 | refcount_set(&cvm_ops->refcnt, 1); |
7fa0a1da JH |
195 | |
196 | vma->vm_ops = &cvm_ops->vm_ops; | |
197 | } | |
198 | return ret; | |
1da177e4 LT |
199 | } |
200 | ||
201 | int coda_open(struct inode *coda_inode, struct file *coda_file) | |
202 | { | |
203 | struct file *host_file = NULL; | |
204 | int error; | |
205 | unsigned short flags = coda_file->f_flags & (~O_EXCL); | |
206 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
207 | struct coda_file_info *cfi; | |
208 | ||
1da177e4 | 209 | cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); |
6ecbc4e1 | 210 | if (!cfi) |
1da177e4 | 211 | return -ENOMEM; |
1da177e4 | 212 | |
1da177e4 | 213 | error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, |
38c2e437 JH |
214 | &host_file); |
215 | if (!host_file) | |
216 | error = -EIO; | |
217 | ||
218 | if (error) { | |
1da177e4 | 219 | kfree(cfi); |
1da177e4 LT |
220 | return error; |
221 | } | |
222 | ||
223 | host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); | |
224 | ||
225 | cfi->cfi_magic = CODA_MAGIC; | |
226 | cfi->cfi_mapcount = 0; | |
227 | cfi->cfi_container = host_file; | |
a9fba24c PC |
228 | /* assume access intents are supported unless we hear otherwise */ |
229 | cfi->cfi_access_intent = true; | |
1da177e4 LT |
230 | |
231 | BUG_ON(coda_file->private_data != NULL); | |
232 | coda_file->private_data = cfi; | |
1da177e4 LT |
233 | return 0; |
234 | } | |
235 | ||
1da177e4 LT |
236 | int coda_release(struct inode *coda_inode, struct file *coda_file) |
237 | { | |
238 | unsigned short flags = (coda_file->f_flags) & (~O_EXCL); | |
239 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
240 | struct coda_file_info *cfi; | |
241 | struct coda_inode_info *cii; | |
242 | struct inode *host_inode; | |
3cf01f28 | 243 | |
5bb44810 | 244 | cfi = coda_ftoc(coda_file); |
1da177e4 | 245 | |
b1deb685 | 246 | venus_close(coda_inode->i_sb, coda_i2f(coda_inode), |
d76b0d9b | 247 | coda_flags, coda_file->f_cred->fsuid); |
1da177e4 | 248 | |
496ad9aa | 249 | host_inode = file_inode(cfi->cfi_container); |
1da177e4 LT |
250 | cii = ITOC(coda_inode); |
251 | ||
252 | /* did we mmap this file? */ | |
b5ce1d83 | 253 | spin_lock(&cii->c_lock); |
1da177e4 LT |
254 | if (coda_inode->i_mapping == &host_inode->i_data) { |
255 | cii->c_mapcount -= cfi->cfi_mapcount; | |
256 | if (!cii->c_mapcount) | |
257 | coda_inode->i_mapping = &coda_inode->i_data; | |
258 | } | |
b5ce1d83 | 259 | spin_unlock(&cii->c_lock); |
1da177e4 LT |
260 | |
261 | fput(cfi->cfi_container); | |
262 | kfree(coda_file->private_data); | |
263 | coda_file->private_data = NULL; | |
264 | ||
d3fec424 JH |
265 | /* VFS fput ignores the return value from file_operations->release, so |
266 | * there is no use returning an error here */ | |
267 | return 0; | |
1da177e4 LT |
268 | } |
269 | ||
02c24a82 | 270 | int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync) |
1da177e4 LT |
271 | { |
272 | struct file *host_file; | |
496ad9aa | 273 | struct inode *coda_inode = file_inode(coda_file); |
1da177e4 | 274 | struct coda_file_info *cfi; |
f7cc02b8 | 275 | int err; |
1da177e4 LT |
276 | |
277 | if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || | |
278 | S_ISLNK(coda_inode->i_mode))) | |
279 | return -EINVAL; | |
280 | ||
02c24a82 JB |
281 | err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end); |
282 | if (err) | |
283 | return err; | |
5955102c | 284 | inode_lock(coda_inode); |
02c24a82 | 285 | |
5bb44810 | 286 | cfi = coda_ftoc(coda_file); |
1da177e4 LT |
287 | host_file = cfi->cfi_container; |
288 | ||
8018ab05 | 289 | err = vfs_fsync(host_file, datasync); |
f7cc02b8 | 290 | if (!err && !datasync) |
1da177e4 | 291 | err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); |
5955102c | 292 | inode_unlock(coda_inode); |
1da177e4 LT |
293 | |
294 | return err; | |
295 | } | |
296 | ||
4b6f5d20 | 297 | const struct file_operations coda_file_operations = { |
1da177e4 | 298 | .llseek = generic_file_llseek, |
c12c49e7 AV |
299 | .read_iter = coda_file_read_iter, |
300 | .write_iter = coda_file_write_iter, | |
1da177e4 LT |
301 | .mmap = coda_file_mmap, |
302 | .open = coda_open, | |
1da177e4 LT |
303 | .release = coda_release, |
304 | .fsync = coda_fsync, | |
82c156f8 | 305 | .splice_read = generic_file_splice_read, |
1da177e4 | 306 | }; |