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Commit | Line | Data |
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1da177e4 | 1 | /* |
f1adc05e | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | * | |
5 | * Ported the filesystem routines to 2.5. | |
6 | * 2003-02-10 Petr Baudis <pasky@ucw.cz> | |
7 | */ | |
8 | ||
1da177e4 | 9 | #include <linux/fs.h> |
1da177e4 | 10 | #include <linux/module.h> |
84b3db04 | 11 | #include <linux/mm.h> |
1da177e4 | 12 | #include <linux/pagemap.h> |
1da177e4 | 13 | #include <linux/statfs.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
dd2cc4df | 15 | #include <linux/seq_file.h> |
6966a977 | 16 | #include <linux/mount.h> |
d0352d3e | 17 | #include <linux/namei.h> |
1da177e4 | 18 | #include "hostfs.h" |
1da177e4 | 19 | #include "init.h" |
84b3db04 | 20 | #include "kern.h" |
1da177e4 LT |
21 | |
22 | struct hostfs_inode_info { | |
1da177e4 | 23 | int fd; |
aeb5d727 | 24 | fmode_t mode; |
1da177e4 LT |
25 | struct inode vfs_inode; |
26 | }; | |
27 | ||
28 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
29 | { | |
f1adc05e | 30 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
31 | } |
32 | ||
680b0da9 | 33 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 | 34 | |
e16404ed | 35 | static int hostfs_d_delete(struct dentry *dentry) |
1da177e4 | 36 | { |
f1adc05e | 37 | return 1; |
1da177e4 LT |
38 | } |
39 | ||
e16404ed | 40 | static const struct dentry_operations hostfs_dentry_ops = { |
1da177e4 LT |
41 | .d_delete = hostfs_d_delete, |
42 | }; | |
43 | ||
44 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 45 | static char *root_ino = ""; |
1da177e4 LT |
46 | static int append = 0; |
47 | ||
48 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
49 | ||
92e1d5be AV |
50 | static const struct inode_operations hostfs_iops; |
51 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 52 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
53 | |
54 | #ifndef MODULE | |
55 | static int __init hostfs_args(char *options, int *add) | |
56 | { | |
57 | char *ptr; | |
58 | ||
59 | ptr = strchr(options, ','); | |
84b3db04 | 60 | if (ptr != NULL) |
1da177e4 | 61 | *ptr++ = '\0'; |
84b3db04 | 62 | if (*options != '\0') |
1da177e4 LT |
63 | root_ino = options; |
64 | ||
65 | options = ptr; | |
84b3db04 | 66 | while (options) { |
1da177e4 | 67 | ptr = strchr(options, ','); |
84b3db04 | 68 | if (ptr != NULL) |
1da177e4 | 69 | *ptr++ = '\0'; |
84b3db04 JD |
70 | if (*options != '\0') { |
71 | if (!strcmp(options, "append")) | |
1da177e4 LT |
72 | append = 1; |
73 | else printf("hostfs_args - unsupported option - %s\n", | |
74 | options); | |
75 | } | |
76 | options = ptr; | |
77 | } | |
f1adc05e | 78 | return 0; |
1da177e4 LT |
79 | } |
80 | ||
81 | __uml_setup("hostfs=", hostfs_args, | |
82 | "hostfs=<root dir>,<flags>,...\n" | |
83 | " This is used to set hostfs parameters. The root directory argument\n" | |
84 | " is used to confine all hostfs mounts to within the specified directory\n" | |
85 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
86 | " mount anything on the host that's accessible to the user that's running\n" | |
87 | " it.\n" | |
88 | " The only flag currently supported is 'append', which specifies that all\n" | |
89 | " files opened by hostfs will be opened in append mode.\n\n" | |
90 | ); | |
91 | #endif | |
92 | ||
c5322220 | 93 | static char *dentry_name(struct dentry *dentry) |
1da177e4 LT |
94 | { |
95 | struct dentry *parent; | |
96 | char *root, *name; | |
97 | int len; | |
98 | ||
99 | len = 0; | |
100 | parent = dentry; | |
84b3db04 | 101 | while (parent->d_parent != parent) { |
1da177e4 LT |
102 | len += parent->d_name.len + 1; |
103 | parent = parent->d_parent; | |
104 | } | |
105 | ||
601d2c38 | 106 | root = parent->d_sb->s_fs_info; |
1da177e4 | 107 | len += strlen(root); |
c5322220 | 108 | name = kmalloc(len + 1, GFP_KERNEL); |
84b3db04 | 109 | if (name == NULL) |
f1adc05e | 110 | return NULL; |
1da177e4 LT |
111 | |
112 | name[len] = '\0'; | |
113 | parent = dentry; | |
84b3db04 | 114 | while (parent->d_parent != parent) { |
1da177e4 LT |
115 | len -= parent->d_name.len + 1; |
116 | name[len] = '/'; | |
117 | strncpy(&name[len + 1], parent->d_name.name, | |
118 | parent->d_name.len); | |
119 | parent = parent->d_parent; | |
120 | } | |
121 | strncpy(name, root, strlen(root)); | |
f1adc05e | 122 | return name; |
1da177e4 LT |
123 | } |
124 | ||
c5322220 | 125 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
126 | { |
127 | struct dentry *dentry; | |
128 | ||
129 | dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); | |
c5322220 | 130 | return dentry_name(dentry); |
1da177e4 LT |
131 | } |
132 | ||
1da177e4 LT |
133 | static char *follow_link(char *link) |
134 | { | |
135 | int len, n; | |
136 | char *name, *resolved, *end; | |
137 | ||
138 | len = 64; | |
84b3db04 | 139 | while (1) { |
1da177e4 LT |
140 | n = -ENOMEM; |
141 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 142 | if (name == NULL) |
1da177e4 LT |
143 | goto out; |
144 | ||
ea7e743e | 145 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 146 | if (n < len) |
1da177e4 LT |
147 | break; |
148 | len *= 2; | |
149 | kfree(name); | |
150 | } | |
84b3db04 | 151 | if (n < 0) |
1da177e4 LT |
152 | goto out_free; |
153 | ||
84b3db04 | 154 | if (*name == '/') |
f1adc05e | 155 | return name; |
1da177e4 LT |
156 | |
157 | end = strrchr(link, '/'); | |
84b3db04 | 158 | if (end == NULL) |
f1adc05e | 159 | return name; |
1da177e4 LT |
160 | |
161 | *(end + 1) = '\0'; | |
162 | len = strlen(link) + strlen(name) + 1; | |
163 | ||
164 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 165 | if (resolved == NULL) { |
1da177e4 LT |
166 | n = -ENOMEM; |
167 | goto out_free; | |
168 | } | |
169 | ||
170 | sprintf(resolved, "%s%s", link, name); | |
171 | kfree(name); | |
172 | kfree(link); | |
f1adc05e | 173 | return resolved; |
1da177e4 LT |
174 | |
175 | out_free: | |
176 | kfree(name); | |
177 | out: | |
f1adc05e | 178 | return ERR_PTR(n); |
1da177e4 LT |
179 | } |
180 | ||
0a370e5d DH |
181 | static struct inode *hostfs_iget(struct super_block *sb) |
182 | { | |
52b209f7 | 183 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
184 | if (!inode) |
185 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
186 | return inode; |
187 | } | |
188 | ||
726c3342 | 189 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 190 | { |
84b3db04 JD |
191 | /* |
192 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
193 | * struct statfs still has 32-bit versions for most of these fields, |
194 | * so we convert them here | |
195 | */ | |
196 | int err; | |
197 | long long f_blocks; | |
198 | long long f_bfree; | |
199 | long long f_bavail; | |
200 | long long f_files; | |
201 | long long f_ffree; | |
202 | ||
601d2c38 | 203 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
204 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
205 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
206 | &sf->f_namelen, sf->f_spare); | |
84b3db04 | 207 | if (err) |
f1adc05e | 208 | return err; |
1da177e4 LT |
209 | sf->f_blocks = f_blocks; |
210 | sf->f_bfree = f_bfree; | |
211 | sf->f_bavail = f_bavail; | |
212 | sf->f_files = f_files; | |
213 | sf->f_ffree = f_ffree; | |
214 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 215 | return 0; |
1da177e4 LT |
216 | } |
217 | ||
218 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
219 | { | |
220 | struct hostfs_inode_info *hi; | |
221 | ||
601d2c38 | 222 | hi = kzalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 223 | if (hi == NULL) |
f1adc05e | 224 | return NULL; |
601d2c38 | 225 | hi->fd = -1; |
1da177e4 | 226 | inode_init_once(&hi->vfs_inode); |
f1adc05e | 227 | return &hi->vfs_inode; |
1da177e4 LT |
228 | } |
229 | ||
e971a6d7 | 230 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 231 | { |
fef26658 | 232 | truncate_inode_pages(&inode->i_data, 0); |
e971a6d7 | 233 | end_writeback(inode); |
84b3db04 | 234 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
235 | close_file(&HOSTFS_I(inode)->fd); |
236 | HOSTFS_I(inode)->fd = -1; | |
237 | } | |
1da177e4 LT |
238 | } |
239 | ||
240 | static void hostfs_destroy_inode(struct inode *inode) | |
241 | { | |
1da177e4 LT |
242 | kfree(HOSTFS_I(inode)); |
243 | } | |
244 | ||
dd2cc4df MS |
245 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
246 | { | |
601d2c38 | 247 | const char *root_path = vfs->mnt_sb->s_fs_info; |
dd2cc4df MS |
248 | size_t offset = strlen(root_ino) + 1; |
249 | ||
250 | if (strlen(root_path) > offset) | |
251 | seq_printf(seq, ",%s", root_path + offset); | |
252 | ||
253 | return 0; | |
254 | } | |
255 | ||
ee9b6d61 | 256 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 257 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 258 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 259 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 260 | .statfs = hostfs_statfs, |
dd2cc4df | 261 | .show_options = hostfs_show_options, |
1da177e4 LT |
262 | }; |
263 | ||
264 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
265 | { | |
266 | void *dir; | |
267 | char *name; | |
268 | unsigned long long next, ino; | |
269 | int error, len; | |
270 | ||
c5322220 | 271 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 272 | if (name == NULL) |
f1adc05e | 273 | return -ENOMEM; |
1da177e4 LT |
274 | dir = open_dir(name, &error); |
275 | kfree(name); | |
84b3db04 | 276 | if (dir == NULL) |
f1adc05e | 277 | return -error; |
1da177e4 | 278 | next = file->f_pos; |
84b3db04 | 279 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
280 | error = (*filldir)(ent, name, len, file->f_pos, |
281 | ino, DT_UNKNOWN); | |
84b3db04 | 282 | if (error) break; |
1da177e4 LT |
283 | file->f_pos = next; |
284 | } | |
285 | close_dir(dir); | |
f1adc05e | 286 | return 0; |
1da177e4 LT |
287 | } |
288 | ||
289 | int hostfs_file_open(struct inode *ino, struct file *file) | |
290 | { | |
291 | char *name; | |
aeb5d727 AV |
292 | fmode_t mode = 0; |
293 | int r = 0, w = 0, fd; | |
1da177e4 LT |
294 | |
295 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 296 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 297 | return 0; |
1da177e4 | 298 | |
84b3db04 JD |
299 | /* |
300 | * The file may already have been opened, but with the wrong access, | |
1da177e4 LT |
301 | * so this resets things and reopens the file with the new access. |
302 | */ | |
84b3db04 | 303 | if (HOSTFS_I(ino)->fd != -1) { |
1da177e4 LT |
304 | close_file(&HOSTFS_I(ino)->fd); |
305 | HOSTFS_I(ino)->fd = -1; | |
306 | } | |
307 | ||
308 | HOSTFS_I(ino)->mode |= mode; | |
84b3db04 | 309 | if (HOSTFS_I(ino)->mode & FMODE_READ) |
1da177e4 | 310 | r = 1; |
84b3db04 | 311 | if (HOSTFS_I(ino)->mode & FMODE_WRITE) |
1da177e4 | 312 | w = 1; |
84b3db04 | 313 | if (w) |
1da177e4 LT |
314 | r = 1; |
315 | ||
c5322220 | 316 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 317 | if (name == NULL) |
f1adc05e | 318 | return -ENOMEM; |
1da177e4 LT |
319 | |
320 | fd = open_file(name, r, w, append); | |
321 | kfree(name); | |
84b3db04 | 322 | if (fd < 0) |
f1adc05e | 323 | return fd; |
1da177e4 LT |
324 | FILE_HOSTFS_I(file)->fd = fd; |
325 | ||
f1adc05e | 326 | return 0; |
1da177e4 LT |
327 | } |
328 | ||
7ea80859 | 329 | int hostfs_fsync(struct file *file, int datasync) |
1da177e4 | 330 | { |
7ea80859 | 331 | return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); |
1da177e4 LT |
332 | } |
333 | ||
4b6f5d20 | 334 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 335 | .llseek = generic_file_llseek, |
543ade1f | 336 | .read = do_sync_read, |
5ffc4ef4 | 337 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
338 | .aio_read = generic_file_aio_read, |
339 | .aio_write = generic_file_aio_write, | |
543ade1f | 340 | .write = do_sync_write, |
1da177e4 LT |
341 | .mmap = generic_file_mmap, |
342 | .open = hostfs_file_open, | |
343 | .release = NULL, | |
344 | .fsync = hostfs_fsync, | |
345 | }; | |
346 | ||
4b6f5d20 | 347 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
348 | .llseek = generic_file_llseek, |
349 | .readdir = hostfs_readdir, | |
350 | .read = generic_read_dir, | |
351 | }; | |
352 | ||
353 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
354 | { | |
355 | struct address_space *mapping = page->mapping; | |
356 | struct inode *inode = mapping->host; | |
357 | char *buffer; | |
358 | unsigned long long base; | |
359 | int count = PAGE_CACHE_SIZE; | |
360 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
361 | int err; | |
362 | ||
363 | if (page->index >= end_index) | |
364 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
365 | ||
366 | buffer = kmap(page); | |
367 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
368 | ||
369 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 370 | if (err != count) { |
1da177e4 LT |
371 | ClearPageUptodate(page); |
372 | goto out; | |
373 | } | |
374 | ||
375 | if (base > inode->i_size) | |
376 | inode->i_size = base; | |
377 | ||
378 | if (PageError(page)) | |
379 | ClearPageError(page); | |
380 | err = 0; | |
381 | ||
382 | out: | |
383 | kunmap(page); | |
384 | ||
385 | unlock_page(page); | |
386 | return err; | |
387 | } | |
388 | ||
389 | int hostfs_readpage(struct file *file, struct page *page) | |
390 | { | |
391 | char *buffer; | |
392 | long long start; | |
393 | int err = 0; | |
394 | ||
395 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
396 | buffer = kmap(page); | |
397 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
398 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
399 | if (err < 0) |
400 | goto out; | |
1da177e4 LT |
401 | |
402 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
403 | ||
404 | flush_dcache_page(page); | |
405 | SetPageUptodate(page); | |
406 | if (PageError(page)) ClearPageError(page); | |
407 | err = 0; | |
408 | out: | |
409 | kunmap(page); | |
410 | unlock_page(page); | |
f1adc05e | 411 | return err; |
1da177e4 LT |
412 | } |
413 | ||
ae361ff4 NP |
414 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
415 | loff_t pos, unsigned len, unsigned flags, | |
416 | struct page **pagep, void **fsdata) | |
1da177e4 | 417 | { |
ae361ff4 | 418 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 419 | |
54566b2c | 420 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
421 | if (!*pagep) |
422 | return -ENOMEM; | |
423 | return 0; | |
1da177e4 LT |
424 | } |
425 | ||
ae361ff4 NP |
426 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
427 | loff_t pos, unsigned len, unsigned copied, | |
428 | struct page *page, void *fsdata) | |
1da177e4 | 429 | { |
1da177e4 | 430 | struct inode *inode = mapping->host; |
ae361ff4 NP |
431 | void *buffer; |
432 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
433 | int err; | |
1da177e4 | 434 | |
1da177e4 | 435 | buffer = kmap(page); |
ae361ff4 NP |
436 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
437 | kunmap(page); | |
30f04a4e | 438 | |
ae361ff4 NP |
439 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
440 | SetPageUptodate(page); | |
30f04a4e | 441 | |
84b3db04 JD |
442 | /* |
443 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
444 | * i_size against the last byte written. |
445 | */ | |
446 | if (err > 0 && (pos > inode->i_size)) | |
447 | inode->i_size = pos; | |
448 | unlock_page(page); | |
449 | page_cache_release(page); | |
1da177e4 | 450 | |
f1adc05e | 451 | return err; |
1da177e4 LT |
452 | } |
453 | ||
f5e54d6e | 454 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
455 | .writepage = hostfs_writepage, |
456 | .readpage = hostfs_readpage, | |
ffa0aea6 | 457 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
458 | .write_begin = hostfs_write_begin, |
459 | .write_end = hostfs_write_end, | |
1da177e4 LT |
460 | }; |
461 | ||
4754b825 | 462 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 463 | { |
4754b825 AV |
464 | dev_t rdev; |
465 | struct hostfs_stat st; | |
466 | int err = stat_file(name, &st, -1); | |
467 | if (err) | |
468 | return err; | |
1da177e4 | 469 | |
5e2df28c | 470 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 471 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 472 | |
4754b825 AV |
473 | switch (st.mode & S_IFMT) { |
474 | case S_IFLNK: | |
d0352d3e | 475 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 476 | break; |
4754b825 AV |
477 | case S_IFDIR: |
478 | ino->i_op = &hostfs_dir_iops; | |
479 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 480 | break; |
4754b825 AV |
481 | case S_IFCHR: |
482 | case S_IFBLK: | |
483 | case S_IFIFO: | |
484 | case S_IFSOCK: | |
485 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
486 | ino->i_op = &hostfs_iops; | |
1da177e4 | 487 | break; |
4754b825 AV |
488 | |
489 | default: | |
490 | ino->i_op = &hostfs_iops; | |
491 | ino->i_fop = &hostfs_file_fops; | |
492 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 493 | } |
4754b825 AV |
494 | |
495 | ino->i_ino = st.ino; | |
496 | ino->i_mode = st.mode; | |
497 | ino->i_nlink = st.nlink; | |
498 | ino->i_uid = st.uid; | |
499 | ino->i_gid = st.gid; | |
500 | ino->i_atime = st.atime; | |
501 | ino->i_mtime = st.mtime; | |
502 | ino->i_ctime = st.ctime; | |
503 | ino->i_size = st.size; | |
504 | ino->i_blocks = st.blocks; | |
505 | return 0; | |
1da177e4 LT |
506 | } |
507 | ||
508 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 509 | struct nameidata *nd) |
1da177e4 LT |
510 | { |
511 | struct inode *inode; | |
512 | char *name; | |
513 | int error, fd; | |
514 | ||
0a370e5d DH |
515 | inode = hostfs_iget(dir->i_sb); |
516 | if (IS_ERR(inode)) { | |
517 | error = PTR_ERR(inode); | |
84b3db04 | 518 | goto out; |
0a370e5d | 519 | } |
1da177e4 | 520 | |
1da177e4 | 521 | error = -ENOMEM; |
c5322220 | 522 | name = dentry_name(dentry); |
84b3db04 | 523 | if (name == NULL) |
1da177e4 LT |
524 | goto out_put; |
525 | ||
526 | fd = file_create(name, | |
527 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
528 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
529 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 530 | if (fd < 0) |
1da177e4 | 531 | error = fd; |
4754b825 | 532 | else |
5e2df28c | 533 | error = read_name(inode, name); |
1da177e4 LT |
534 | |
535 | kfree(name); | |
84b3db04 | 536 | if (error) |
1da177e4 LT |
537 | goto out_put; |
538 | ||
539 | HOSTFS_I(inode)->fd = fd; | |
540 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
541 | d_instantiate(dentry, inode); | |
f1adc05e | 542 | return 0; |
1da177e4 LT |
543 | |
544 | out_put: | |
545 | iput(inode); | |
546 | out: | |
f1adc05e | 547 | return error; |
1da177e4 LT |
548 | } |
549 | ||
550 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 551 | struct nameidata *nd) |
1da177e4 LT |
552 | { |
553 | struct inode *inode; | |
554 | char *name; | |
555 | int err; | |
556 | ||
0a370e5d DH |
557 | inode = hostfs_iget(ino->i_sb); |
558 | if (IS_ERR(inode)) { | |
559 | err = PTR_ERR(inode); | |
1da177e4 | 560 | goto out; |
0a370e5d | 561 | } |
1da177e4 | 562 | |
1da177e4 | 563 | err = -ENOMEM; |
c5322220 | 564 | name = dentry_name(dentry); |
84b3db04 | 565 | if (name == NULL) |
1da177e4 LT |
566 | goto out_put; |
567 | ||
568 | err = read_name(inode, name); | |
5e2df28c | 569 | |
1da177e4 | 570 | kfree(name); |
84b3db04 | 571 | if (err == -ENOENT) { |
1da177e4 LT |
572 | iput(inode); |
573 | inode = NULL; | |
574 | } | |
84b3db04 | 575 | else if (err) |
1da177e4 LT |
576 | goto out_put; |
577 | ||
578 | d_add(dentry, inode); | |
579 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 580 | return NULL; |
1da177e4 LT |
581 | |
582 | out_put: | |
583 | iput(inode); | |
584 | out: | |
f1adc05e | 585 | return ERR_PTR(err); |
1da177e4 LT |
586 | } |
587 | ||
1da177e4 LT |
588 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
589 | { | |
f1adc05e JD |
590 | char *from_name, *to_name; |
591 | int err; | |
1da177e4 | 592 | |
c5322220 | 593 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 594 | return -ENOMEM; |
c5322220 | 595 | to_name = dentry_name(to); |
84b3db04 | 596 | if (to_name == NULL) { |
1da177e4 | 597 | kfree(from_name); |
f1adc05e | 598 | return -ENOMEM; |
1da177e4 | 599 | } |
f1adc05e JD |
600 | err = link_file(to_name, from_name); |
601 | kfree(from_name); | |
602 | kfree(to_name); | |
603 | return err; | |
1da177e4 LT |
604 | } |
605 | ||
606 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
607 | { | |
608 | char *file; | |
609 | int err; | |
610 | ||
c5322220 | 611 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 612 | return -ENOMEM; |
84b3db04 | 613 | if (append) |
f1adc05e | 614 | return -EPERM; |
1da177e4 LT |
615 | |
616 | err = unlink_file(file); | |
617 | kfree(file); | |
f1adc05e | 618 | return err; |
1da177e4 LT |
619 | } |
620 | ||
621 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
622 | { | |
623 | char *file; | |
624 | int err; | |
625 | ||
c5322220 | 626 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 627 | return -ENOMEM; |
1da177e4 LT |
628 | err = make_symlink(file, to); |
629 | kfree(file); | |
f1adc05e | 630 | return err; |
1da177e4 LT |
631 | } |
632 | ||
633 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
634 | { | |
635 | char *file; | |
636 | int err; | |
637 | ||
c5322220 | 638 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 639 | return -ENOMEM; |
1da177e4 LT |
640 | err = do_mkdir(file, mode); |
641 | kfree(file); | |
f1adc05e | 642 | return err; |
1da177e4 LT |
643 | } |
644 | ||
645 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
646 | { | |
647 | char *file; | |
648 | int err; | |
649 | ||
c5322220 | 650 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 651 | return -ENOMEM; |
1da177e4 LT |
652 | err = do_rmdir(file); |
653 | kfree(file); | |
f1adc05e | 654 | return err; |
1da177e4 LT |
655 | } |
656 | ||
657 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
658 | { | |
659 | struct inode *inode; | |
660 | char *name; | |
0a370e5d | 661 | int err; |
1da177e4 | 662 | |
0a370e5d DH |
663 | inode = hostfs_iget(dir->i_sb); |
664 | if (IS_ERR(inode)) { | |
665 | err = PTR_ERR(inode); | |
1da177e4 | 666 | goto out; |
0a370e5d | 667 | } |
1da177e4 | 668 | |
1da177e4 | 669 | err = -ENOMEM; |
c5322220 | 670 | name = dentry_name(dentry); |
84b3db04 | 671 | if (name == NULL) |
1da177e4 LT |
672 | goto out_put; |
673 | ||
674 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 675 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
84b3db04 | 676 | if (err) |
1da177e4 LT |
677 | goto out_free; |
678 | ||
679 | err = read_name(inode, name); | |
5e2df28c AV |
680 | if (err) |
681 | goto out_put; | |
1da177e4 | 682 | kfree(name); |
84b3db04 | 683 | if (err) |
1da177e4 LT |
684 | goto out_put; |
685 | ||
686 | d_instantiate(dentry, inode); | |
f1adc05e | 687 | return 0; |
1da177e4 LT |
688 | |
689 | out_free: | |
690 | kfree(name); | |
691 | out_put: | |
692 | iput(inode); | |
693 | out: | |
f1adc05e | 694 | return err; |
1da177e4 LT |
695 | } |
696 | ||
697 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
698 | struct inode *to_ino, struct dentry *to) | |
699 | { | |
700 | char *from_name, *to_name; | |
701 | int err; | |
702 | ||
c5322220 | 703 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 704 | return -ENOMEM; |
c5322220 | 705 | if ((to_name = dentry_name(to)) == NULL) { |
1da177e4 | 706 | kfree(from_name); |
f1adc05e | 707 | return -ENOMEM; |
1da177e4 LT |
708 | } |
709 | err = rename_file(from_name, to_name); | |
710 | kfree(from_name); | |
711 | kfree(to_name); | |
f1adc05e | 712 | return err; |
1da177e4 LT |
713 | } |
714 | ||
e6305c43 | 715 | int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
716 | { |
717 | char *name; | |
718 | int r = 0, w = 0, x = 0, err; | |
719 | ||
720 | if (desired & MAY_READ) r = 1; | |
721 | if (desired & MAY_WRITE) w = 1; | |
722 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 723 | name = inode_name(ino); |
f1adc05e JD |
724 | if (name == NULL) |
725 | return -ENOMEM; | |
1da177e4 LT |
726 | |
727 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 728 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
729 | err = 0; |
730 | else | |
731 | err = access_file(name, r, w, x); | |
732 | kfree(name); | |
84b3db04 | 733 | if (!err) |
1da177e4 LT |
734 | err = generic_permission(ino, desired, NULL); |
735 | return err; | |
736 | } | |
737 | ||
738 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
739 | { | |
1025774c | 740 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
741 | struct hostfs_iattr attrs; |
742 | char *name; | |
743 | int err; | |
744 | ||
1025774c | 745 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 746 | |
1025774c | 747 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
748 | if (err) |
749 | return err; | |
750 | ||
84b3db04 | 751 | if (append) |
1da177e4 LT |
752 | attr->ia_valid &= ~ATTR_SIZE; |
753 | ||
754 | attrs.ia_valid = 0; | |
84b3db04 | 755 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
756 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
757 | attrs.ia_mode = attr->ia_mode; | |
758 | } | |
84b3db04 | 759 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
760 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
761 | attrs.ia_uid = attr->ia_uid; | |
762 | } | |
84b3db04 | 763 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
764 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
765 | attrs.ia_gid = attr->ia_gid; | |
766 | } | |
84b3db04 | 767 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
768 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
769 | attrs.ia_size = attr->ia_size; | |
770 | } | |
84b3db04 | 771 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
772 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
773 | attrs.ia_atime = attr->ia_atime; | |
774 | } | |
84b3db04 | 775 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
776 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
777 | attrs.ia_mtime = attr->ia_mtime; | |
778 | } | |
84b3db04 | 779 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
780 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
781 | attrs.ia_ctime = attr->ia_ctime; | |
782 | } | |
84b3db04 | 783 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
784 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
785 | } | |
84b3db04 | 786 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
787 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
788 | } | |
c5322220 | 789 | name = dentry_name(dentry); |
84b3db04 | 790 | if (name == NULL) |
f1adc05e | 791 | return -ENOMEM; |
5822b7fa | 792 | err = set_attr(name, &attrs, fd); |
1da177e4 | 793 | kfree(name); |
84b3db04 | 794 | if (err) |
f1adc05e | 795 | return err; |
1da177e4 | 796 | |
1025774c CH |
797 | if ((attr->ia_valid & ATTR_SIZE) && |
798 | attr->ia_size != i_size_read(inode)) { | |
799 | int error; | |
800 | ||
801 | error = vmtruncate(inode, attr->ia_size); | |
802 | if (err) | |
803 | return err; | |
804 | } | |
805 | ||
806 | setattr_copy(inode, attr); | |
807 | mark_inode_dirty(inode); | |
808 | return 0; | |
1da177e4 LT |
809 | } |
810 | ||
92e1d5be | 811 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
812 | .create = hostfs_create, |
813 | .link = hostfs_link, | |
814 | .unlink = hostfs_unlink, | |
815 | .symlink = hostfs_symlink, | |
816 | .mkdir = hostfs_mkdir, | |
817 | .rmdir = hostfs_rmdir, | |
818 | .mknod = hostfs_mknod, | |
819 | .rename = hostfs_rename, | |
1da177e4 LT |
820 | .permission = hostfs_permission, |
821 | .setattr = hostfs_setattr, | |
1da177e4 LT |
822 | }; |
823 | ||
92e1d5be | 824 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
825 | .create = hostfs_create, |
826 | .lookup = hostfs_lookup, | |
827 | .link = hostfs_link, | |
828 | .unlink = hostfs_unlink, | |
829 | .symlink = hostfs_symlink, | |
830 | .mkdir = hostfs_mkdir, | |
831 | .rmdir = hostfs_rmdir, | |
832 | .mknod = hostfs_mknod, | |
833 | .rename = hostfs_rename, | |
1da177e4 LT |
834 | .permission = hostfs_permission, |
835 | .setattr = hostfs_setattr, | |
1da177e4 LT |
836 | }; |
837 | ||
d0352d3e AV |
838 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
839 | { | |
840 | char *link = __getname(); | |
841 | if (link) { | |
842 | char *path = dentry_name(dentry); | |
843 | int err = -ENOMEM; | |
844 | if (path) { | |
845 | int err = hostfs_do_readlink(path, link, PATH_MAX); | |
846 | if (err == PATH_MAX) | |
847 | err = -E2BIG; | |
848 | kfree(path); | |
849 | } | |
850 | if (err < 0) { | |
851 | __putname(link); | |
852 | link = ERR_PTR(err); | |
853 | } | |
854 | } else { | |
855 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 856 | } |
d0352d3e AV |
857 | |
858 | nd_set_link(nd, link); | |
859 | return NULL; | |
860 | } | |
861 | ||
862 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
863 | { | |
864 | char *s = nd_get_link(nd); | |
865 | if (!IS_ERR(s)) | |
866 | __putname(s); | |
1da177e4 LT |
867 | } |
868 | ||
d0352d3e AV |
869 | static const struct inode_operations hostfs_link_iops = { |
870 | .readlink = generic_readlink, | |
871 | .follow_link = hostfs_follow_link, | |
872 | .put_link = hostfs_put_link, | |
1da177e4 LT |
873 | }; |
874 | ||
875 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
876 | { | |
877 | struct inode *root_inode; | |
75e8defb | 878 | char *host_root_path, *req_root = d; |
1da177e4 LT |
879 | int err; |
880 | ||
881 | sb->s_blocksize = 1024; | |
882 | sb->s_blocksize_bits = 10; | |
883 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
884 | sb->s_op = &hostfs_sbops; | |
752fa51e | 885 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 886 | |
a6eb0be6 | 887 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
888 | if (req_root == NULL) |
889 | req_root = ""; | |
1da177e4 LT |
890 | |
891 | err = -ENOMEM; | |
601d2c38 AV |
892 | sb->s_fs_info = host_root_path = |
893 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 894 | if (host_root_path == NULL) |
1da177e4 LT |
895 | goto out; |
896 | ||
75e8defb | 897 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 898 | |
52b209f7 AV |
899 | root_inode = new_inode(sb); |
900 | if (!root_inode) | |
601d2c38 | 901 | goto out; |
1da177e4 | 902 | |
4754b825 AV |
903 | err = read_name(root_inode, host_root_path); |
904 | if (err) | |
905 | goto out_put; | |
52b209f7 | 906 | |
4754b825 | 907 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
908 | char *name = follow_link(host_root_path); |
909 | if (IS_ERR(name)) | |
910 | err = PTR_ERR(name); | |
911 | else | |
912 | err = read_name(root_inode, name); | |
913 | kfree(name); | |
4754b825 AV |
914 | if (err) |
915 | goto out_put; | |
52b209f7 | 916 | } |
1da177e4 | 917 | |
1da177e4 LT |
918 | err = -ENOMEM; |
919 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 920 | if (sb->s_root == NULL) |
1da177e4 LT |
921 | goto out_put; |
922 | ||
f1adc05e | 923 | return 0; |
1da177e4 | 924 | |
f1adc05e JD |
925 | out_put: |
926 | iput(root_inode); | |
f1adc05e JD |
927 | out: |
928 | return err; | |
1da177e4 LT |
929 | } |
930 | ||
454e2398 DH |
931 | static int hostfs_read_sb(struct file_system_type *type, |
932 | int flags, const char *dev_name, | |
933 | void *data, struct vfsmount *mnt) | |
1da177e4 | 934 | { |
454e2398 | 935 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
936 | } |
937 | ||
601d2c38 AV |
938 | static void hostfs_kill_sb(struct super_block *s) |
939 | { | |
940 | kill_anon_super(s); | |
941 | kfree(s->s_fs_info); | |
942 | } | |
943 | ||
1da177e4 LT |
944 | static struct file_system_type hostfs_type = { |
945 | .owner = THIS_MODULE, | |
946 | .name = "hostfs", | |
947 | .get_sb = hostfs_read_sb, | |
601d2c38 | 948 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
949 | .fs_flags = 0, |
950 | }; | |
951 | ||
952 | static int __init init_hostfs(void) | |
953 | { | |
f1adc05e | 954 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
955 | } |
956 | ||
957 | static void __exit exit_hostfs(void) | |
958 | { | |
959 | unregister_filesystem(&hostfs_type); | |
960 | } | |
961 | ||
962 | module_init(init_hostfs) | |
963 | module_exit(exit_hostfs) | |
964 | MODULE_LICENSE("GPL"); |