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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/errno.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/string.h> | |
19 | #include <asm/uaccess.h> | |
20 | ||
21 | #include <linux/coda.h> | |
22 | #include <linux/coda_linux.h> | |
23 | #include <linux/coda_fs_i.h> | |
24 | #include <linux/coda_psdev.h> | |
25 | ||
26 | #include "coda_int.h" | |
27 | ||
28 | /* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support | |
29 | * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */ | |
30 | static int use_coda_close; | |
31 | ||
32 | static ssize_t | |
33 | coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) | |
34 | { | |
35 | struct coda_file_info *cfi; | |
36 | struct file *host_file; | |
37 | ||
38 | cfi = CODA_FTOC(coda_file); | |
39 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
40 | host_file = cfi->cfi_container; | |
41 | ||
42 | if (!host_file->f_op || !host_file->f_op->read) | |
43 | return -EINVAL; | |
44 | ||
45 | return host_file->f_op->read(host_file, buf, count, ppos); | |
46 | } | |
47 | ||
48 | static ssize_t | |
49 | coda_file_splice_read(struct file *coda_file, loff_t *ppos, | |
50 | struct pipe_inode_info *pipe, size_t count, | |
51 | unsigned int flags) | |
52 | { | |
53 | struct coda_file_info *cfi; | |
54 | struct file *host_file; | |
55 | ||
56 | cfi = CODA_FTOC(coda_file); | |
57 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
58 | host_file = cfi->cfi_container; | |
59 | ||
60 | if (!host_file->f_op || !host_file->f_op->splice_read) | |
61 | return -EINVAL; | |
62 | ||
63 | return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags); | |
64 | } | |
65 | ||
66 | static ssize_t | |
67 | coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) | |
68 | { | |
69 | struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode; | |
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 || !host_file->f_op->write) | |
79 | return -EINVAL; | |
80 | ||
81 | host_inode = host_file->f_path.dentry->d_inode; | |
82 | mutex_lock(&coda_inode->i_mutex); | |
83 | ||
84 | ret = host_file->f_op->write(host_file, buf, count, ppos); | |
85 | ||
86 | coda_inode->i_size = host_inode->i_size; | |
87 | coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; | |
88 | coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; | |
89 | mutex_unlock(&coda_inode->i_mutex); | |
90 | ||
91 | return ret; | |
92 | } | |
93 | ||
94 | static int | |
95 | coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) | |
96 | { | |
97 | struct coda_file_info *cfi; | |
98 | struct coda_inode_info *cii; | |
99 | struct file *host_file; | |
100 | struct inode *coda_inode, *host_inode; | |
101 | ||
102 | cfi = CODA_FTOC(coda_file); | |
103 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
104 | host_file = cfi->cfi_container; | |
105 | ||
106 | if (!host_file->f_op || !host_file->f_op->mmap) | |
107 | return -ENODEV; | |
108 | ||
109 | coda_inode = coda_file->f_path.dentry->d_inode; | |
110 | host_inode = host_file->f_path.dentry->d_inode; | |
111 | coda_file->f_mapping = host_file->f_mapping; | |
112 | if (coda_inode->i_mapping == &coda_inode->i_data) | |
113 | coda_inode->i_mapping = host_inode->i_mapping; | |
114 | ||
115 | /* only allow additional mmaps as long as userspace isn't changing | |
116 | * the container file on us! */ | |
117 | else if (coda_inode->i_mapping != host_inode->i_mapping) | |
118 | return -EBUSY; | |
119 | ||
120 | /* keep track of how often the coda_inode/host_file has been mmapped */ | |
121 | cii = ITOC(coda_inode); | |
122 | cii->c_mapcount++; | |
123 | cfi->cfi_mapcount++; | |
124 | ||
125 | return host_file->f_op->mmap(host_file, vma); | |
126 | } | |
127 | ||
128 | int coda_open(struct inode *coda_inode, struct file *coda_file) | |
129 | { | |
130 | struct file *host_file = NULL; | |
131 | int error; | |
132 | unsigned short flags = coda_file->f_flags & (~O_EXCL); | |
133 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
134 | struct coda_file_info *cfi; | |
135 | ||
136 | cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); | |
137 | if (!cfi) | |
138 | return -ENOMEM; | |
139 | ||
140 | lock_kernel(); | |
141 | ||
142 | error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, | |
143 | &host_file); | |
144 | if (!host_file) | |
145 | error = -EIO; | |
146 | ||
147 | if (error) { | |
148 | kfree(cfi); | |
149 | unlock_kernel(); | |
150 | return error; | |
151 | } | |
152 | ||
153 | host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); | |
154 | ||
155 | cfi->cfi_magic = CODA_MAGIC; | |
156 | cfi->cfi_mapcount = 0; | |
157 | cfi->cfi_container = host_file; | |
158 | ||
159 | BUG_ON(coda_file->private_data != NULL); | |
160 | coda_file->private_data = cfi; | |
161 | ||
162 | unlock_kernel(); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | int coda_flush(struct file *coda_file, fl_owner_t id) | |
167 | { | |
168 | unsigned short flags = coda_file->f_flags & ~O_EXCL; | |
169 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
170 | struct coda_file_info *cfi; | |
171 | struct inode *coda_inode; | |
172 | int err = 0, fcnt; | |
173 | ||
174 | lock_kernel(); | |
175 | ||
176 | /* last close semantics */ | |
177 | fcnt = file_count(coda_file); | |
178 | if (fcnt > 1) | |
179 | goto out; | |
180 | ||
181 | /* No need to make an upcall when we have not made any modifications | |
182 | * to the file */ | |
183 | if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY) | |
184 | goto out; | |
185 | ||
186 | if (use_coda_close) | |
187 | goto out; | |
188 | ||
189 | cfi = CODA_FTOC(coda_file); | |
190 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
191 | ||
192 | coda_inode = coda_file->f_path.dentry->d_inode; | |
193 | ||
194 | err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, | |
195 | coda_file->f_uid); | |
196 | ||
197 | if (err == -EOPNOTSUPP) { | |
198 | use_coda_close = 1; | |
199 | err = 0; | |
200 | } | |
201 | ||
202 | out: | |
203 | unlock_kernel(); | |
204 | return err; | |
205 | } | |
206 | ||
207 | int coda_release(struct inode *coda_inode, struct file *coda_file) | |
208 | { | |
209 | unsigned short flags = (coda_file->f_flags) & (~O_EXCL); | |
210 | unsigned short coda_flags = coda_flags_to_cflags(flags); | |
211 | struct coda_file_info *cfi; | |
212 | struct coda_inode_info *cii; | |
213 | struct inode *host_inode; | |
214 | int err = 0; | |
215 | ||
216 | lock_kernel(); | |
217 | ||
218 | if (!use_coda_close) { | |
219 | err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode), | |
220 | coda_flags); | |
221 | if (err == -EOPNOTSUPP) { | |
222 | use_coda_close = 1; | |
223 | err = 0; | |
224 | } | |
225 | } | |
226 | ||
227 | cfi = CODA_FTOC(coda_file); | |
228 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
229 | ||
230 | if (use_coda_close) | |
231 | err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), | |
232 | coda_flags, coda_file->f_uid); | |
233 | ||
234 | host_inode = cfi->cfi_container->f_path.dentry->d_inode; | |
235 | cii = ITOC(coda_inode); | |
236 | ||
237 | /* did we mmap this file? */ | |
238 | if (coda_inode->i_mapping == &host_inode->i_data) { | |
239 | cii->c_mapcount -= cfi->cfi_mapcount; | |
240 | if (!cii->c_mapcount) | |
241 | coda_inode->i_mapping = &coda_inode->i_data; | |
242 | } | |
243 | ||
244 | fput(cfi->cfi_container); | |
245 | kfree(coda_file->private_data); | |
246 | coda_file->private_data = NULL; | |
247 | ||
248 | unlock_kernel(); | |
249 | return err; | |
250 | } | |
251 | ||
252 | int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) | |
253 | { | |
254 | struct file *host_file; | |
255 | struct dentry *host_dentry; | |
256 | struct inode *host_inode, *coda_inode = coda_dentry->d_inode; | |
257 | struct coda_file_info *cfi; | |
258 | int err = 0; | |
259 | ||
260 | if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || | |
261 | S_ISLNK(coda_inode->i_mode))) | |
262 | return -EINVAL; | |
263 | ||
264 | cfi = CODA_FTOC(coda_file); | |
265 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); | |
266 | host_file = cfi->cfi_container; | |
267 | ||
268 | if (host_file->f_op && host_file->f_op->fsync) { | |
269 | host_dentry = host_file->f_path.dentry; | |
270 | host_inode = host_dentry->d_inode; | |
271 | mutex_lock(&host_inode->i_mutex); | |
272 | err = host_file->f_op->fsync(host_file, host_dentry, datasync); | |
273 | mutex_unlock(&host_inode->i_mutex); | |
274 | } | |
275 | ||
276 | if ( !err && !datasync ) { | |
277 | lock_kernel(); | |
278 | err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); | |
279 | unlock_kernel(); | |
280 | } | |
281 | ||
282 | return err; | |
283 | } | |
284 | ||
285 | const struct file_operations coda_file_operations = { | |
286 | .llseek = generic_file_llseek, | |
287 | .read = coda_file_read, | |
288 | .write = coda_file_write, | |
289 | .mmap = coda_file_mmap, | |
290 | .open = coda_open, | |
291 | .flush = coda_flush, | |
292 | .release = coda_release, | |
293 | .fsync = coda_fsync, | |
294 | .splice_read = coda_file_splice_read, | |
295 | }; | |
296 |