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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> |
a1be2935 | 26 | #include <linux/splice.h> |
1da177e4 LT |
27 | |
28 | #include <linux/coda.h> | |
8fc8b9df | 29 | #include "coda_psdev.h" |
31a203df | 30 | #include "coda_linux.h" |
c98d8cfb AB |
31 | #include "coda_int.h" |
32 | ||
7fa0a1da | 33 | struct coda_vm_ops { |
1077c285 | 34 | refcount_t refcnt; |
7fa0a1da JH |
35 | struct file *coda_file; |
36 | const struct vm_operations_struct *host_vm_ops; | |
37 | struct vm_operations_struct vm_ops; | |
38 | }; | |
39 | ||
1da177e4 | 40 | static ssize_t |
c12c49e7 | 41 | coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 | 42 | { |
c12c49e7 | 43 | struct file *coda_file = iocb->ki_filp; |
a9fba24c | 44 | struct inode *coda_inode = file_inode(coda_file); |
5bb44810 | 45 | struct coda_file_info *cfi = coda_ftoc(coda_file); |
a9fba24c PC |
46 | loff_t ki_pos = iocb->ki_pos; |
47 | size_t count = iov_iter_count(to); | |
48 | ssize_t ret; | |
49 | ||
50 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
51 | &cfi->cfi_access_intent, | |
52 | count, ki_pos, CODA_ACCESS_TYPE_READ); | |
53 | if (ret) | |
54 | goto finish_read; | |
55 | ||
56 | ret = vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0); | |
1da177e4 | 57 | |
a9fba24c PC |
58 | finish_read: |
59 | venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
60 | &cfi->cfi_access_intent, | |
61 | count, ki_pos, CODA_ACCESS_TYPE_READ_FINISH); | |
62 | return ret; | |
1da177e4 LT |
63 | } |
64 | ||
1da177e4 | 65 | static ssize_t |
c12c49e7 | 66 | coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 | 67 | { |
c12c49e7 AV |
68 | struct file *coda_file = iocb->ki_filp; |
69 | struct inode *coda_inode = file_inode(coda_file); | |
5bb44810 | 70 | struct coda_file_info *cfi = coda_ftoc(coda_file); |
a9fba24c PC |
71 | struct file *host_file = cfi->cfi_container; |
72 | loff_t ki_pos = iocb->ki_pos; | |
73 | size_t count = iov_iter_count(to); | |
1da177e4 LT |
74 | ssize_t ret; |
75 | ||
a9fba24c PC |
76 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), |
77 | &cfi->cfi_access_intent, | |
78 | count, ki_pos, CODA_ACCESS_TYPE_WRITE); | |
79 | if (ret) | |
80 | goto finish_write; | |
81 | ||
5955102c | 82 | inode_lock(coda_inode); |
e389b76a | 83 | file_start_write(host_file); |
abbb6589 | 84 | ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0); |
c12c49e7 | 85 | coda_inode->i_size = file_inode(host_file)->i_size; |
1da177e4 | 86 | coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; |
581a4d00 | 87 | inode_set_mtime_to_ts(coda_inode, inode_set_ctime_current(coda_inode)); |
03d95eb2 | 88 | file_end_write(host_file); |
e389b76a | 89 | inode_unlock(coda_inode); |
a9fba24c PC |
90 | |
91 | finish_write: | |
92 | venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
93 | &cfi->cfi_access_intent, | |
94 | count, ki_pos, CODA_ACCESS_TYPE_WRITE_FINISH); | |
1da177e4 LT |
95 | return ret; |
96 | } | |
97 | ||
a1be2935 DH |
98 | static ssize_t |
99 | coda_file_splice_read(struct file *coda_file, loff_t *ppos, | |
100 | struct pipe_inode_info *pipe, | |
101 | size_t len, unsigned int flags) | |
102 | { | |
103 | struct inode *coda_inode = file_inode(coda_file); | |
104 | struct coda_file_info *cfi = coda_ftoc(coda_file); | |
105 | struct file *in = cfi->cfi_container; | |
106 | loff_t ki_pos = *ppos; | |
107 | ssize_t ret; | |
108 | ||
109 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
110 | &cfi->cfi_access_intent, | |
111 | len, ki_pos, CODA_ACCESS_TYPE_READ); | |
112 | if (ret) | |
113 | goto finish_read; | |
114 | ||
115 | ret = vfs_splice_read(in, ppos, pipe, len, flags); | |
116 | ||
117 | finish_read: | |
118 | venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
119 | &cfi->cfi_access_intent, | |
120 | len, ki_pos, CODA_ACCESS_TYPE_READ_FINISH); | |
121 | return ret; | |
122 | } | |
123 | ||
7fa0a1da JH |
124 | static void |
125 | coda_vm_open(struct vm_area_struct *vma) | |
126 | { | |
127 | struct coda_vm_ops *cvm_ops = | |
128 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); | |
129 | ||
1077c285 | 130 | refcount_inc(&cvm_ops->refcnt); |
7fa0a1da JH |
131 | |
132 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open) | |
133 | cvm_ops->host_vm_ops->open(vma); | |
134 | } | |
135 | ||
136 | static void | |
137 | coda_vm_close(struct vm_area_struct *vma) | |
138 | { | |
139 | struct coda_vm_ops *cvm_ops = | |
140 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); | |
141 | ||
142 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close) | |
143 | cvm_ops->host_vm_ops->close(vma); | |
144 | ||
1077c285 | 145 | if (refcount_dec_and_test(&cvm_ops->refcnt)) { |
7fa0a1da JH |
146 | vma->vm_ops = cvm_ops->host_vm_ops; |
147 | fput(cvm_ops->coda_file); | |
148 | kfree(cvm_ops); | |
149 | } | |
150 | } | |
151 | ||
1da177e4 LT |
152 | static int |
153 | coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) | |
154 | { | |
a9fba24c PC |
155 | struct inode *coda_inode = file_inode(coda_file); |
156 | struct coda_file_info *cfi = coda_ftoc(coda_file); | |
157 | struct file *host_file = cfi->cfi_container; | |
158 | struct inode *host_inode = file_inode(host_file); | |
1da177e4 | 159 | struct coda_inode_info *cii; |
7fa0a1da | 160 | struct coda_vm_ops *cvm_ops; |
a9fba24c PC |
161 | loff_t ppos; |
162 | size_t count; | |
7fa0a1da | 163 | int ret; |
1da177e4 | 164 | |
72c2d531 | 165 | if (!host_file->f_op->mmap) |
1da177e4 LT |
166 | return -ENODEV; |
167 | ||
7fa0a1da JH |
168 | if (WARN_ON(coda_file != vma->vm_file)) |
169 | return -EIO; | |
170 | ||
a9fba24c PC |
171 | count = vma->vm_end - vma->vm_start; |
172 | ppos = vma->vm_pgoff * PAGE_SIZE; | |
173 | ||
174 | ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode), | |
175 | &cfi->cfi_access_intent, | |
176 | count, ppos, CODA_ACCESS_TYPE_MMAP); | |
177 | if (ret) | |
178 | return ret; | |
179 | ||
7fa0a1da JH |
180 | cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL); |
181 | if (!cvm_ops) | |
182 | return -ENOMEM; | |
183 | ||
b5ce1d83 YA |
184 | cii = ITOC(coda_inode); |
185 | spin_lock(&cii->c_lock); | |
1da177e4 LT |
186 | coda_file->f_mapping = host_file->f_mapping; |
187 | if (coda_inode->i_mapping == &coda_inode->i_data) | |
188 | coda_inode->i_mapping = host_inode->i_mapping; | |
189 | ||
190 | /* only allow additional mmaps as long as userspace isn't changing | |
191 | * the container file on us! */ | |
b5ce1d83 YA |
192 | else if (coda_inode->i_mapping != host_inode->i_mapping) { |
193 | spin_unlock(&cii->c_lock); | |
7fa0a1da | 194 | kfree(cvm_ops); |
1da177e4 | 195 | return -EBUSY; |
b5ce1d83 | 196 | } |
1da177e4 LT |
197 | |
198 | /* keep track of how often the coda_inode/host_file has been mmapped */ | |
1da177e4 LT |
199 | cii->c_mapcount++; |
200 | cfi->cfi_mapcount++; | |
b5ce1d83 | 201 | spin_unlock(&cii->c_lock); |
1da177e4 | 202 | |
7fa0a1da JH |
203 | vma->vm_file = get_file(host_file); |
204 | ret = call_mmap(vma->vm_file, vma); | |
205 | ||
206 | if (ret) { | |
9da29c7f CK |
207 | /* if call_mmap fails, our caller will put host_file so we |
208 | * should drop the reference to the coda_file that we got. | |
7fa0a1da | 209 | */ |
9da29c7f | 210 | fput(coda_file); |
7fa0a1da JH |
211 | kfree(cvm_ops); |
212 | } else { | |
213 | /* here we add redirects for the open/close vm_operations */ | |
214 | cvm_ops->host_vm_ops = vma->vm_ops; | |
215 | if (vma->vm_ops) | |
216 | cvm_ops->vm_ops = *vma->vm_ops; | |
217 | ||
218 | cvm_ops->vm_ops.open = coda_vm_open; | |
219 | cvm_ops->vm_ops.close = coda_vm_close; | |
220 | cvm_ops->coda_file = coda_file; | |
1077c285 | 221 | refcount_set(&cvm_ops->refcnt, 1); |
7fa0a1da JH |
222 | |
223 | vma->vm_ops = &cvm_ops->vm_ops; | |
224 | } | |
225 | return ret; | |
1da177e4 LT |
226 | } |
227 | ||
228 | int coda_open(struct inode *coda_inode, struct file *coda_file) | |
229 | { | |
230 | struct file *host_file = NULL; | |
231 | int error; | |
232 | unsigned short flags = coda_file->f_flags & (~O_EXCL); | |
233 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
234 | struct coda_file_info *cfi; | |
235 | ||
1da177e4 | 236 | cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); |
6ecbc4e1 | 237 | if (!cfi) |
1da177e4 | 238 | return -ENOMEM; |
1da177e4 | 239 | |
1da177e4 | 240 | error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, |
38c2e437 JH |
241 | &host_file); |
242 | if (!host_file) | |
243 | error = -EIO; | |
244 | ||
245 | if (error) { | |
1da177e4 | 246 | kfree(cfi); |
1da177e4 LT |
247 | return error; |
248 | } | |
249 | ||
250 | host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); | |
251 | ||
252 | cfi->cfi_magic = CODA_MAGIC; | |
253 | cfi->cfi_mapcount = 0; | |
254 | cfi->cfi_container = host_file; | |
a9fba24c PC |
255 | /* assume access intents are supported unless we hear otherwise */ |
256 | cfi->cfi_access_intent = true; | |
1da177e4 LT |
257 | |
258 | BUG_ON(coda_file->private_data != NULL); | |
259 | coda_file->private_data = cfi; | |
1da177e4 LT |
260 | return 0; |
261 | } | |
262 | ||
1da177e4 LT |
263 | int coda_release(struct inode *coda_inode, struct file *coda_file) |
264 | { | |
265 | unsigned short flags = (coda_file->f_flags) & (~O_EXCL); | |
266 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
267 | struct coda_file_info *cfi; | |
268 | struct coda_inode_info *cii; | |
269 | struct inode *host_inode; | |
3cf01f28 | 270 | |
5bb44810 | 271 | cfi = coda_ftoc(coda_file); |
1da177e4 | 272 | |
b1deb685 | 273 | venus_close(coda_inode->i_sb, coda_i2f(coda_inode), |
d76b0d9b | 274 | coda_flags, coda_file->f_cred->fsuid); |
1da177e4 | 275 | |
496ad9aa | 276 | host_inode = file_inode(cfi->cfi_container); |
1da177e4 LT |
277 | cii = ITOC(coda_inode); |
278 | ||
279 | /* did we mmap this file? */ | |
b5ce1d83 | 280 | spin_lock(&cii->c_lock); |
1da177e4 LT |
281 | if (coda_inode->i_mapping == &host_inode->i_data) { |
282 | cii->c_mapcount -= cfi->cfi_mapcount; | |
283 | if (!cii->c_mapcount) | |
284 | coda_inode->i_mapping = &coda_inode->i_data; | |
285 | } | |
b5ce1d83 | 286 | spin_unlock(&cii->c_lock); |
1da177e4 LT |
287 | |
288 | fput(cfi->cfi_container); | |
289 | kfree(coda_file->private_data); | |
290 | coda_file->private_data = NULL; | |
291 | ||
d3fec424 JH |
292 | /* VFS fput ignores the return value from file_operations->release, so |
293 | * there is no use returning an error here */ | |
294 | return 0; | |
1da177e4 LT |
295 | } |
296 | ||
02c24a82 | 297 | int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync) |
1da177e4 LT |
298 | { |
299 | struct file *host_file; | |
496ad9aa | 300 | struct inode *coda_inode = file_inode(coda_file); |
1da177e4 | 301 | struct coda_file_info *cfi; |
f7cc02b8 | 302 | int err; |
1da177e4 LT |
303 | |
304 | if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || | |
305 | S_ISLNK(coda_inode->i_mode))) | |
306 | return -EINVAL; | |
307 | ||
02c24a82 JB |
308 | err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end); |
309 | if (err) | |
310 | return err; | |
5955102c | 311 | inode_lock(coda_inode); |
02c24a82 | 312 | |
5bb44810 | 313 | cfi = coda_ftoc(coda_file); |
1da177e4 LT |
314 | host_file = cfi->cfi_container; |
315 | ||
8018ab05 | 316 | err = vfs_fsync(host_file, datasync); |
f7cc02b8 | 317 | if (!err && !datasync) |
1da177e4 | 318 | err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); |
5955102c | 319 | inode_unlock(coda_inode); |
1da177e4 LT |
320 | |
321 | return err; | |
322 | } | |
323 | ||
4b6f5d20 | 324 | const struct file_operations coda_file_operations = { |
1da177e4 | 325 | .llseek = generic_file_llseek, |
c12c49e7 AV |
326 | .read_iter = coda_file_read_iter, |
327 | .write_iter = coda_file_write_iter, | |
1da177e4 LT |
328 | .mmap = coda_file_mmap, |
329 | .open = coda_open, | |
1da177e4 LT |
330 | .release = coda_release, |
331 | .fsync = coda_fsync, | |
a1be2935 | 332 | .splice_read = coda_file_splice_read, |
1da177e4 | 333 | }; |