]>
Commit | Line | Data |
---|---|---|
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> |
1da177e4 | 17 | #include "hostfs.h" |
1da177e4 | 18 | #include "init.h" |
84b3db04 | 19 | #include "kern.h" |
1da177e4 LT |
20 | |
21 | struct hostfs_inode_info { | |
1da177e4 | 22 | int fd; |
aeb5d727 | 23 | fmode_t mode; |
1da177e4 LT |
24 | struct inode vfs_inode; |
25 | }; | |
26 | ||
27 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
28 | { | |
f1adc05e | 29 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
30 | } |
31 | ||
680b0da9 | 32 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 | 33 | |
e16404ed | 34 | static int hostfs_d_delete(struct dentry *dentry) |
1da177e4 | 35 | { |
f1adc05e | 36 | return 1; |
1da177e4 LT |
37 | } |
38 | ||
e16404ed | 39 | static const struct dentry_operations hostfs_dentry_ops = { |
1da177e4 LT |
40 | .d_delete = hostfs_d_delete, |
41 | }; | |
42 | ||
43 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 44 | static char *root_ino = ""; |
1da177e4 LT |
45 | static int append = 0; |
46 | ||
47 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
48 | ||
92e1d5be AV |
49 | static const struct inode_operations hostfs_iops; |
50 | static const struct inode_operations hostfs_dir_iops; | |
f5e54d6e | 51 | static const struct address_space_operations hostfs_link_aops; |
1da177e4 LT |
52 | |
53 | #ifndef MODULE | |
54 | static int __init hostfs_args(char *options, int *add) | |
55 | { | |
56 | char *ptr; | |
57 | ||
58 | ptr = strchr(options, ','); | |
84b3db04 | 59 | if (ptr != NULL) |
1da177e4 | 60 | *ptr++ = '\0'; |
84b3db04 | 61 | if (*options != '\0') |
1da177e4 LT |
62 | root_ino = options; |
63 | ||
64 | options = ptr; | |
84b3db04 | 65 | while (options) { |
1da177e4 | 66 | ptr = strchr(options, ','); |
84b3db04 | 67 | if (ptr != NULL) |
1da177e4 | 68 | *ptr++ = '\0'; |
84b3db04 JD |
69 | if (*options != '\0') { |
70 | if (!strcmp(options, "append")) | |
1da177e4 LT |
71 | append = 1; |
72 | else printf("hostfs_args - unsupported option - %s\n", | |
73 | options); | |
74 | } | |
75 | options = ptr; | |
76 | } | |
f1adc05e | 77 | return 0; |
1da177e4 LT |
78 | } |
79 | ||
80 | __uml_setup("hostfs=", hostfs_args, | |
81 | "hostfs=<root dir>,<flags>,...\n" | |
82 | " This is used to set hostfs parameters. The root directory argument\n" | |
83 | " is used to confine all hostfs mounts to within the specified directory\n" | |
84 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
85 | " mount anything on the host that's accessible to the user that's running\n" | |
86 | " it.\n" | |
87 | " The only flag currently supported is 'append', which specifies that all\n" | |
88 | " files opened by hostfs will be opened in append mode.\n\n" | |
89 | ); | |
90 | #endif | |
91 | ||
92 | static char *dentry_name(struct dentry *dentry, int extra) | |
93 | { | |
94 | struct dentry *parent; | |
95 | char *root, *name; | |
96 | int len; | |
97 | ||
98 | len = 0; | |
99 | parent = dentry; | |
84b3db04 | 100 | while (parent->d_parent != parent) { |
1da177e4 LT |
101 | len += parent->d_name.len + 1; |
102 | parent = parent->d_parent; | |
103 | } | |
104 | ||
601d2c38 | 105 | root = parent->d_sb->s_fs_info; |
1da177e4 LT |
106 | len += strlen(root); |
107 | name = kmalloc(len + extra + 1, GFP_KERNEL); | |
84b3db04 | 108 | if (name == NULL) |
f1adc05e | 109 | return NULL; |
1da177e4 LT |
110 | |
111 | name[len] = '\0'; | |
112 | parent = dentry; | |
84b3db04 | 113 | while (parent->d_parent != parent) { |
1da177e4 LT |
114 | len -= parent->d_name.len + 1; |
115 | name[len] = '/'; | |
116 | strncpy(&name[len + 1], parent->d_name.name, | |
117 | parent->d_name.len); | |
118 | parent = parent->d_parent; | |
119 | } | |
120 | strncpy(name, root, strlen(root)); | |
f1adc05e | 121 | return name; |
1da177e4 LT |
122 | } |
123 | ||
124 | static char *inode_name(struct inode *ino, int extra) | |
125 | { | |
126 | struct dentry *dentry; | |
127 | ||
128 | dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); | |
f1adc05e | 129 | return dentry_name(dentry, extra); |
1da177e4 LT |
130 | } |
131 | ||
132 | static int read_name(struct inode *ino, char *name) | |
133 | { | |
39b743c6 AV |
134 | struct hostfs_stat st; |
135 | int err = stat_file(name, &st, -1); | |
84b3db04 | 136 | if (err) |
f1adc05e | 137 | return err; |
1da177e4 | 138 | |
39b743c6 AV |
139 | ino->i_ino = st.ino; |
140 | ino->i_mode = st.mode; | |
141 | ino->i_nlink = st.nlink; | |
142 | ino->i_uid = st.uid; | |
143 | ino->i_gid = st.gid; | |
144 | ino->i_atime = st.atime; | |
145 | ino->i_mtime = st.mtime; | |
146 | ino->i_ctime = st.ctime; | |
147 | ino->i_size = st.size; | |
148 | ino->i_blocks = st.blocks; | |
f1adc05e | 149 | return 0; |
1da177e4 LT |
150 | } |
151 | ||
152 | static char *follow_link(char *link) | |
153 | { | |
154 | int len, n; | |
155 | char *name, *resolved, *end; | |
156 | ||
157 | len = 64; | |
84b3db04 | 158 | while (1) { |
1da177e4 LT |
159 | n = -ENOMEM; |
160 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 161 | if (name == NULL) |
1da177e4 LT |
162 | goto out; |
163 | ||
ea7e743e | 164 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 165 | if (n < len) |
1da177e4 LT |
166 | break; |
167 | len *= 2; | |
168 | kfree(name); | |
169 | } | |
84b3db04 | 170 | if (n < 0) |
1da177e4 LT |
171 | goto out_free; |
172 | ||
84b3db04 | 173 | if (*name == '/') |
f1adc05e | 174 | return name; |
1da177e4 LT |
175 | |
176 | end = strrchr(link, '/'); | |
84b3db04 | 177 | if (end == NULL) |
f1adc05e | 178 | return name; |
1da177e4 LT |
179 | |
180 | *(end + 1) = '\0'; | |
181 | len = strlen(link) + strlen(name) + 1; | |
182 | ||
183 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 184 | if (resolved == NULL) { |
1da177e4 LT |
185 | n = -ENOMEM; |
186 | goto out_free; | |
187 | } | |
188 | ||
189 | sprintf(resolved, "%s%s", link, name); | |
190 | kfree(name); | |
191 | kfree(link); | |
f1adc05e | 192 | return resolved; |
1da177e4 LT |
193 | |
194 | out_free: | |
195 | kfree(name); | |
196 | out: | |
f1adc05e | 197 | return ERR_PTR(n); |
1da177e4 LT |
198 | } |
199 | ||
0a370e5d DH |
200 | static struct inode *hostfs_iget(struct super_block *sb) |
201 | { | |
52b209f7 | 202 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
203 | if (!inode) |
204 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
205 | return inode; |
206 | } | |
207 | ||
726c3342 | 208 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 209 | { |
84b3db04 JD |
210 | /* |
211 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
212 | * struct statfs still has 32-bit versions for most of these fields, |
213 | * so we convert them here | |
214 | */ | |
215 | int err; | |
216 | long long f_blocks; | |
217 | long long f_bfree; | |
218 | long long f_bavail; | |
219 | long long f_files; | |
220 | long long f_ffree; | |
221 | ||
601d2c38 | 222 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
223 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
224 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
225 | &sf->f_namelen, sf->f_spare); | |
84b3db04 | 226 | if (err) |
f1adc05e | 227 | return err; |
1da177e4 LT |
228 | sf->f_blocks = f_blocks; |
229 | sf->f_bfree = f_bfree; | |
230 | sf->f_bavail = f_bavail; | |
231 | sf->f_files = f_files; | |
232 | sf->f_ffree = f_ffree; | |
233 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 234 | return 0; |
1da177e4 LT |
235 | } |
236 | ||
237 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
238 | { | |
239 | struct hostfs_inode_info *hi; | |
240 | ||
601d2c38 | 241 | hi = kzalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 242 | if (hi == NULL) |
f1adc05e | 243 | return NULL; |
601d2c38 | 244 | hi->fd = -1; |
1da177e4 | 245 | inode_init_once(&hi->vfs_inode); |
f1adc05e | 246 | return &hi->vfs_inode; |
1da177e4 LT |
247 | } |
248 | ||
e971a6d7 | 249 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 250 | { |
fef26658 | 251 | truncate_inode_pages(&inode->i_data, 0); |
e971a6d7 | 252 | end_writeback(inode); |
84b3db04 | 253 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
254 | close_file(&HOSTFS_I(inode)->fd); |
255 | HOSTFS_I(inode)->fd = -1; | |
256 | } | |
1da177e4 LT |
257 | } |
258 | ||
259 | static void hostfs_destroy_inode(struct inode *inode) | |
260 | { | |
1da177e4 LT |
261 | kfree(HOSTFS_I(inode)); |
262 | } | |
263 | ||
dd2cc4df MS |
264 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
265 | { | |
601d2c38 | 266 | const char *root_path = vfs->mnt_sb->s_fs_info; |
dd2cc4df MS |
267 | size_t offset = strlen(root_ino) + 1; |
268 | ||
269 | if (strlen(root_path) > offset) | |
270 | seq_printf(seq, ",%s", root_path + offset); | |
271 | ||
272 | return 0; | |
273 | } | |
274 | ||
ee9b6d61 | 275 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 276 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 277 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 278 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 279 | .statfs = hostfs_statfs, |
dd2cc4df | 280 | .show_options = hostfs_show_options, |
1da177e4 LT |
281 | }; |
282 | ||
283 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
284 | { | |
285 | void *dir; | |
286 | char *name; | |
287 | unsigned long long next, ino; | |
288 | int error, len; | |
289 | ||
680b0da9 | 290 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 291 | if (name == NULL) |
f1adc05e | 292 | return -ENOMEM; |
1da177e4 LT |
293 | dir = open_dir(name, &error); |
294 | kfree(name); | |
84b3db04 | 295 | if (dir == NULL) |
f1adc05e | 296 | return -error; |
1da177e4 | 297 | next = file->f_pos; |
84b3db04 | 298 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
299 | error = (*filldir)(ent, name, len, file->f_pos, |
300 | ino, DT_UNKNOWN); | |
84b3db04 | 301 | if (error) break; |
1da177e4 LT |
302 | file->f_pos = next; |
303 | } | |
304 | close_dir(dir); | |
f1adc05e | 305 | return 0; |
1da177e4 LT |
306 | } |
307 | ||
308 | int hostfs_file_open(struct inode *ino, struct file *file) | |
309 | { | |
310 | char *name; | |
aeb5d727 AV |
311 | fmode_t mode = 0; |
312 | int r = 0, w = 0, fd; | |
1da177e4 LT |
313 | |
314 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 315 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 316 | return 0; |
1da177e4 | 317 | |
84b3db04 JD |
318 | /* |
319 | * The file may already have been opened, but with the wrong access, | |
1da177e4 LT |
320 | * so this resets things and reopens the file with the new access. |
321 | */ | |
84b3db04 | 322 | if (HOSTFS_I(ino)->fd != -1) { |
1da177e4 LT |
323 | close_file(&HOSTFS_I(ino)->fd); |
324 | HOSTFS_I(ino)->fd = -1; | |
325 | } | |
326 | ||
327 | HOSTFS_I(ino)->mode |= mode; | |
84b3db04 | 328 | if (HOSTFS_I(ino)->mode & FMODE_READ) |
1da177e4 | 329 | r = 1; |
84b3db04 | 330 | if (HOSTFS_I(ino)->mode & FMODE_WRITE) |
1da177e4 | 331 | w = 1; |
84b3db04 | 332 | if (w) |
1da177e4 LT |
333 | r = 1; |
334 | ||
680b0da9 | 335 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 336 | if (name == NULL) |
f1adc05e | 337 | return -ENOMEM; |
1da177e4 LT |
338 | |
339 | fd = open_file(name, r, w, append); | |
340 | kfree(name); | |
84b3db04 | 341 | if (fd < 0) |
f1adc05e | 342 | return fd; |
1da177e4 LT |
343 | FILE_HOSTFS_I(file)->fd = fd; |
344 | ||
f1adc05e | 345 | return 0; |
1da177e4 LT |
346 | } |
347 | ||
7ea80859 | 348 | int hostfs_fsync(struct file *file, int datasync) |
1da177e4 | 349 | { |
7ea80859 | 350 | return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); |
1da177e4 LT |
351 | } |
352 | ||
4b6f5d20 | 353 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 354 | .llseek = generic_file_llseek, |
543ade1f | 355 | .read = do_sync_read, |
5ffc4ef4 | 356 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
357 | .aio_read = generic_file_aio_read, |
358 | .aio_write = generic_file_aio_write, | |
543ade1f | 359 | .write = do_sync_write, |
1da177e4 LT |
360 | .mmap = generic_file_mmap, |
361 | .open = hostfs_file_open, | |
362 | .release = NULL, | |
363 | .fsync = hostfs_fsync, | |
364 | }; | |
365 | ||
4b6f5d20 | 366 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
367 | .llseek = generic_file_llseek, |
368 | .readdir = hostfs_readdir, | |
369 | .read = generic_read_dir, | |
370 | }; | |
371 | ||
372 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
373 | { | |
374 | struct address_space *mapping = page->mapping; | |
375 | struct inode *inode = mapping->host; | |
376 | char *buffer; | |
377 | unsigned long long base; | |
378 | int count = PAGE_CACHE_SIZE; | |
379 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
380 | int err; | |
381 | ||
382 | if (page->index >= end_index) | |
383 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
384 | ||
385 | buffer = kmap(page); | |
386 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
387 | ||
388 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 389 | if (err != count) { |
1da177e4 LT |
390 | ClearPageUptodate(page); |
391 | goto out; | |
392 | } | |
393 | ||
394 | if (base > inode->i_size) | |
395 | inode->i_size = base; | |
396 | ||
397 | if (PageError(page)) | |
398 | ClearPageError(page); | |
399 | err = 0; | |
400 | ||
401 | out: | |
402 | kunmap(page); | |
403 | ||
404 | unlock_page(page); | |
405 | return err; | |
406 | } | |
407 | ||
408 | int hostfs_readpage(struct file *file, struct page *page) | |
409 | { | |
410 | char *buffer; | |
411 | long long start; | |
412 | int err = 0; | |
413 | ||
414 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
415 | buffer = kmap(page); | |
416 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
417 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
418 | if (err < 0) |
419 | goto out; | |
1da177e4 LT |
420 | |
421 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
422 | ||
423 | flush_dcache_page(page); | |
424 | SetPageUptodate(page); | |
425 | if (PageError(page)) ClearPageError(page); | |
426 | err = 0; | |
427 | out: | |
428 | kunmap(page); | |
429 | unlock_page(page); | |
f1adc05e | 430 | return err; |
1da177e4 LT |
431 | } |
432 | ||
ae361ff4 NP |
433 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
434 | loff_t pos, unsigned len, unsigned flags, | |
435 | struct page **pagep, void **fsdata) | |
1da177e4 | 436 | { |
ae361ff4 | 437 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 438 | |
54566b2c | 439 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
440 | if (!*pagep) |
441 | return -ENOMEM; | |
442 | return 0; | |
1da177e4 LT |
443 | } |
444 | ||
ae361ff4 NP |
445 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
446 | loff_t pos, unsigned len, unsigned copied, | |
447 | struct page *page, void *fsdata) | |
1da177e4 | 448 | { |
1da177e4 | 449 | struct inode *inode = mapping->host; |
ae361ff4 NP |
450 | void *buffer; |
451 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
452 | int err; | |
1da177e4 | 453 | |
1da177e4 | 454 | buffer = kmap(page); |
ae361ff4 NP |
455 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
456 | kunmap(page); | |
30f04a4e | 457 | |
ae361ff4 NP |
458 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
459 | SetPageUptodate(page); | |
30f04a4e | 460 | |
84b3db04 JD |
461 | /* |
462 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
463 | * i_size against the last byte written. |
464 | */ | |
465 | if (err > 0 && (pos > inode->i_size)) | |
466 | inode->i_size = pos; | |
467 | unlock_page(page); | |
468 | page_cache_release(page); | |
1da177e4 | 469 | |
f1adc05e | 470 | return err; |
1da177e4 LT |
471 | } |
472 | ||
f5e54d6e | 473 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
474 | .writepage = hostfs_writepage, |
475 | .readpage = hostfs_readpage, | |
ffa0aea6 | 476 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
477 | .write_begin = hostfs_write_begin, |
478 | .write_end = hostfs_write_end, | |
1da177e4 LT |
479 | }; |
480 | ||
5e2df28c | 481 | static void init_inode(struct inode *inode, char *path) |
1da177e4 | 482 | { |
5e2df28c | 483 | int type; |
1da177e4 LT |
484 | int maj, min; |
485 | dev_t rdev = 0; | |
486 | ||
5e2df28c AV |
487 | type = file_type(path, &maj, &min); |
488 | /* Reencode maj and min with the kernel encoding.*/ | |
489 | rdev = MKDEV(maj, min); | |
1da177e4 | 490 | |
84b3db04 | 491 | if (type == OS_TYPE_SYMLINK) |
1da177e4 | 492 | inode->i_op = &page_symlink_inode_operations; |
84b3db04 | 493 | else if (type == OS_TYPE_DIR) |
1da177e4 LT |
494 | inode->i_op = &hostfs_dir_iops; |
495 | else inode->i_op = &hostfs_iops; | |
496 | ||
84b3db04 | 497 | if (type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; |
1da177e4 LT |
498 | else inode->i_fop = &hostfs_file_fops; |
499 | ||
84b3db04 | 500 | if (type == OS_TYPE_SYMLINK) |
1da177e4 LT |
501 | inode->i_mapping->a_ops = &hostfs_link_aops; |
502 | else inode->i_mapping->a_ops = &hostfs_aops; | |
503 | ||
504 | switch (type) { | |
505 | case OS_TYPE_CHARDEV: | |
506 | init_special_inode(inode, S_IFCHR, rdev); | |
507 | break; | |
508 | case OS_TYPE_BLOCKDEV: | |
509 | init_special_inode(inode, S_IFBLK, rdev); | |
510 | break; | |
511 | case OS_TYPE_FIFO: | |
512 | init_special_inode(inode, S_IFIFO, 0); | |
513 | break; | |
514 | case OS_TYPE_SOCK: | |
515 | init_special_inode(inode, S_IFSOCK, 0); | |
516 | break; | |
517 | } | |
1da177e4 LT |
518 | } |
519 | ||
520 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 521 | struct nameidata *nd) |
1da177e4 LT |
522 | { |
523 | struct inode *inode; | |
524 | char *name; | |
525 | int error, fd; | |
526 | ||
0a370e5d DH |
527 | inode = hostfs_iget(dir->i_sb); |
528 | if (IS_ERR(inode)) { | |
529 | error = PTR_ERR(inode); | |
84b3db04 | 530 | goto out; |
0a370e5d | 531 | } |
1da177e4 | 532 | |
1da177e4 LT |
533 | error = -ENOMEM; |
534 | name = dentry_name(dentry, 0); | |
84b3db04 | 535 | if (name == NULL) |
1da177e4 LT |
536 | goto out_put; |
537 | ||
538 | fd = file_create(name, | |
539 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
540 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
541 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
5e2df28c | 542 | if (fd < 0) { |
1da177e4 | 543 | error = fd; |
5e2df28c AV |
544 | } else { |
545 | error = read_name(inode, name); | |
546 | init_inode(inode, name); | |
547 | } | |
1da177e4 LT |
548 | |
549 | kfree(name); | |
84b3db04 | 550 | if (error) |
1da177e4 LT |
551 | goto out_put; |
552 | ||
553 | HOSTFS_I(inode)->fd = fd; | |
554 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
555 | d_instantiate(dentry, inode); | |
f1adc05e | 556 | return 0; |
1da177e4 LT |
557 | |
558 | out_put: | |
559 | iput(inode); | |
560 | out: | |
f1adc05e | 561 | return error; |
1da177e4 LT |
562 | } |
563 | ||
564 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 565 | struct nameidata *nd) |
1da177e4 LT |
566 | { |
567 | struct inode *inode; | |
568 | char *name; | |
569 | int err; | |
570 | ||
0a370e5d DH |
571 | inode = hostfs_iget(ino->i_sb); |
572 | if (IS_ERR(inode)) { | |
573 | err = PTR_ERR(inode); | |
1da177e4 | 574 | goto out; |
0a370e5d | 575 | } |
1da177e4 | 576 | |
1da177e4 LT |
577 | err = -ENOMEM; |
578 | name = dentry_name(dentry, 0); | |
84b3db04 | 579 | if (name == NULL) |
1da177e4 LT |
580 | goto out_put; |
581 | ||
582 | err = read_name(inode, name); | |
5e2df28c AV |
583 | init_inode(inode, name); |
584 | ||
1da177e4 | 585 | kfree(name); |
84b3db04 | 586 | if (err == -ENOENT) { |
1da177e4 LT |
587 | iput(inode); |
588 | inode = NULL; | |
589 | } | |
84b3db04 | 590 | else if (err) |
1da177e4 LT |
591 | goto out_put; |
592 | ||
593 | d_add(dentry, inode); | |
594 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 595 | return NULL; |
1da177e4 LT |
596 | |
597 | out_put: | |
598 | iput(inode); | |
599 | out: | |
f1adc05e | 600 | return ERR_PTR(err); |
1da177e4 LT |
601 | } |
602 | ||
603 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
604 | { | |
f1adc05e | 605 | char *file; |
1da177e4 LT |
606 | int len; |
607 | ||
608 | file = inode_name(ino, dentry->d_name.len + 1); | |
84b3db04 | 609 | if (file == NULL) |
f1adc05e JD |
610 | return NULL; |
611 | strcat(file, "/"); | |
1da177e4 | 612 | len = strlen(file); |
f1adc05e | 613 | strncat(file, dentry->d_name.name, dentry->d_name.len); |
1da177e4 | 614 | file[len + dentry->d_name.len] = '\0'; |
f1adc05e | 615 | return file; |
1da177e4 LT |
616 | } |
617 | ||
618 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
619 | { | |
f1adc05e JD |
620 | char *from_name, *to_name; |
621 | int err; | |
1da177e4 | 622 | |
84b3db04 | 623 | if ((from_name = inode_dentry_name(ino, from)) == NULL) |
f1adc05e JD |
624 | return -ENOMEM; |
625 | to_name = dentry_name(to, 0); | |
84b3db04 | 626 | if (to_name == NULL) { |
1da177e4 | 627 | kfree(from_name); |
f1adc05e | 628 | return -ENOMEM; |
1da177e4 | 629 | } |
f1adc05e JD |
630 | err = link_file(to_name, from_name); |
631 | kfree(from_name); | |
632 | kfree(to_name); | |
633 | return err; | |
1da177e4 LT |
634 | } |
635 | ||
636 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
637 | { | |
638 | char *file; | |
639 | int err; | |
640 | ||
84b3db04 | 641 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 642 | return -ENOMEM; |
84b3db04 | 643 | if (append) |
f1adc05e | 644 | return -EPERM; |
1da177e4 LT |
645 | |
646 | err = unlink_file(file); | |
647 | kfree(file); | |
f1adc05e | 648 | return err; |
1da177e4 LT |
649 | } |
650 | ||
651 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
652 | { | |
653 | char *file; | |
654 | int err; | |
655 | ||
84b3db04 | 656 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 657 | return -ENOMEM; |
1da177e4 LT |
658 | err = make_symlink(file, to); |
659 | kfree(file); | |
f1adc05e | 660 | return err; |
1da177e4 LT |
661 | } |
662 | ||
663 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
664 | { | |
665 | char *file; | |
666 | int err; | |
667 | ||
84b3db04 | 668 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 669 | return -ENOMEM; |
1da177e4 LT |
670 | err = do_mkdir(file, mode); |
671 | kfree(file); | |
f1adc05e | 672 | return err; |
1da177e4 LT |
673 | } |
674 | ||
675 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
676 | { | |
677 | char *file; | |
678 | int err; | |
679 | ||
84b3db04 | 680 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 681 | return -ENOMEM; |
1da177e4 LT |
682 | err = do_rmdir(file); |
683 | kfree(file); | |
f1adc05e | 684 | return err; |
1da177e4 LT |
685 | } |
686 | ||
687 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
688 | { | |
689 | struct inode *inode; | |
690 | char *name; | |
0a370e5d | 691 | int err; |
1da177e4 | 692 | |
0a370e5d DH |
693 | inode = hostfs_iget(dir->i_sb); |
694 | if (IS_ERR(inode)) { | |
695 | err = PTR_ERR(inode); | |
1da177e4 | 696 | goto out; |
0a370e5d | 697 | } |
1da177e4 | 698 | |
1da177e4 LT |
699 | err = -ENOMEM; |
700 | name = dentry_name(dentry, 0); | |
84b3db04 | 701 | if (name == NULL) |
1da177e4 LT |
702 | goto out_put; |
703 | ||
704 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 705 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
84b3db04 | 706 | if (err) |
1da177e4 LT |
707 | goto out_free; |
708 | ||
709 | err = read_name(inode, name); | |
5e2df28c AV |
710 | init_inode(inode, name); |
711 | if (err) | |
712 | goto out_put; | |
1da177e4 | 713 | kfree(name); |
84b3db04 | 714 | if (err) |
1da177e4 LT |
715 | goto out_put; |
716 | ||
717 | d_instantiate(dentry, inode); | |
f1adc05e | 718 | return 0; |
1da177e4 LT |
719 | |
720 | out_free: | |
721 | kfree(name); | |
722 | out_put: | |
723 | iput(inode); | |
724 | out: | |
f1adc05e | 725 | return err; |
1da177e4 LT |
726 | } |
727 | ||
728 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
729 | struct inode *to_ino, struct dentry *to) | |
730 | { | |
731 | char *from_name, *to_name; | |
732 | int err; | |
733 | ||
84b3db04 | 734 | if ((from_name = inode_dentry_name(from_ino, from)) == NULL) |
f1adc05e | 735 | return -ENOMEM; |
84b3db04 | 736 | if ((to_name = inode_dentry_name(to_ino, to)) == NULL) { |
1da177e4 | 737 | kfree(from_name); |
f1adc05e | 738 | return -ENOMEM; |
1da177e4 LT |
739 | } |
740 | err = rename_file(from_name, to_name); | |
741 | kfree(from_name); | |
742 | kfree(to_name); | |
f1adc05e | 743 | return err; |
1da177e4 LT |
744 | } |
745 | ||
e6305c43 | 746 | int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
747 | { |
748 | char *name; | |
749 | int r = 0, w = 0, x = 0, err; | |
750 | ||
751 | if (desired & MAY_READ) r = 1; | |
752 | if (desired & MAY_WRITE) w = 1; | |
753 | if (desired & MAY_EXEC) x = 1; | |
754 | name = inode_name(ino, 0); | |
f1adc05e JD |
755 | if (name == NULL) |
756 | return -ENOMEM; | |
1da177e4 LT |
757 | |
758 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 759 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
760 | err = 0; |
761 | else | |
762 | err = access_file(name, r, w, x); | |
763 | kfree(name); | |
84b3db04 | 764 | if (!err) |
1da177e4 LT |
765 | err = generic_permission(ino, desired, NULL); |
766 | return err; | |
767 | } | |
768 | ||
769 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
770 | { | |
1025774c | 771 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
772 | struct hostfs_iattr attrs; |
773 | char *name; | |
774 | int err; | |
775 | ||
1025774c | 776 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 777 | |
1025774c | 778 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
779 | if (err) |
780 | return err; | |
781 | ||
84b3db04 | 782 | if (append) |
1da177e4 LT |
783 | attr->ia_valid &= ~ATTR_SIZE; |
784 | ||
785 | attrs.ia_valid = 0; | |
84b3db04 | 786 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
787 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
788 | attrs.ia_mode = attr->ia_mode; | |
789 | } | |
84b3db04 | 790 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
791 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
792 | attrs.ia_uid = attr->ia_uid; | |
793 | } | |
84b3db04 | 794 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
795 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
796 | attrs.ia_gid = attr->ia_gid; | |
797 | } | |
84b3db04 | 798 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
799 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
800 | attrs.ia_size = attr->ia_size; | |
801 | } | |
84b3db04 | 802 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
803 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
804 | attrs.ia_atime = attr->ia_atime; | |
805 | } | |
84b3db04 | 806 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
807 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
808 | attrs.ia_mtime = attr->ia_mtime; | |
809 | } | |
84b3db04 | 810 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
811 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
812 | attrs.ia_ctime = attr->ia_ctime; | |
813 | } | |
84b3db04 | 814 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
815 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
816 | } | |
84b3db04 | 817 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
818 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
819 | } | |
820 | name = dentry_name(dentry, 0); | |
84b3db04 | 821 | if (name == NULL) |
f1adc05e | 822 | return -ENOMEM; |
5822b7fa | 823 | err = set_attr(name, &attrs, fd); |
1da177e4 | 824 | kfree(name); |
84b3db04 | 825 | if (err) |
f1adc05e | 826 | return err; |
1da177e4 | 827 | |
1025774c CH |
828 | if ((attr->ia_valid & ATTR_SIZE) && |
829 | attr->ia_size != i_size_read(inode)) { | |
830 | int error; | |
831 | ||
832 | error = vmtruncate(inode, attr->ia_size); | |
833 | if (err) | |
834 | return err; | |
835 | } | |
836 | ||
837 | setattr_copy(inode, attr); | |
838 | mark_inode_dirty(inode); | |
839 | return 0; | |
1da177e4 LT |
840 | } |
841 | ||
92e1d5be | 842 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
843 | .create = hostfs_create, |
844 | .link = hostfs_link, | |
845 | .unlink = hostfs_unlink, | |
846 | .symlink = hostfs_symlink, | |
847 | .mkdir = hostfs_mkdir, | |
848 | .rmdir = hostfs_rmdir, | |
849 | .mknod = hostfs_mknod, | |
850 | .rename = hostfs_rename, | |
1da177e4 LT |
851 | .permission = hostfs_permission, |
852 | .setattr = hostfs_setattr, | |
1da177e4 LT |
853 | }; |
854 | ||
92e1d5be | 855 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
856 | .create = hostfs_create, |
857 | .lookup = hostfs_lookup, | |
858 | .link = hostfs_link, | |
859 | .unlink = hostfs_unlink, | |
860 | .symlink = hostfs_symlink, | |
861 | .mkdir = hostfs_mkdir, | |
862 | .rmdir = hostfs_rmdir, | |
863 | .mknod = hostfs_mknod, | |
864 | .rename = hostfs_rename, | |
1da177e4 LT |
865 | .permission = hostfs_permission, |
866 | .setattr = hostfs_setattr, | |
1da177e4 LT |
867 | }; |
868 | ||
869 | int hostfs_link_readpage(struct file *file, struct page *page) | |
870 | { | |
871 | char *buffer, *name; | |
1da177e4 LT |
872 | int err; |
873 | ||
1da177e4 LT |
874 | buffer = kmap(page); |
875 | name = inode_name(page->mapping->host, 0); | |
84b3db04 | 876 | if (name == NULL) |
f1adc05e | 877 | return -ENOMEM; |
ea7e743e | 878 | err = hostfs_do_readlink(name, buffer, PAGE_CACHE_SIZE); |
1da177e4 | 879 | kfree(name); |
84b3db04 | 880 | if (err == PAGE_CACHE_SIZE) |
1da177e4 | 881 | err = -E2BIG; |
84b3db04 | 882 | else if (err > 0) { |
1da177e4 LT |
883 | flush_dcache_page(page); |
884 | SetPageUptodate(page); | |
885 | if (PageError(page)) ClearPageError(page); | |
886 | err = 0; | |
887 | } | |
888 | kunmap(page); | |
889 | unlock_page(page); | |
f1adc05e | 890 | return err; |
1da177e4 LT |
891 | } |
892 | ||
f5e54d6e | 893 | static const struct address_space_operations hostfs_link_aops = { |
1da177e4 LT |
894 | .readpage = hostfs_link_readpage, |
895 | }; | |
896 | ||
897 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
898 | { | |
899 | struct inode *root_inode; | |
75e8defb | 900 | char *host_root_path, *req_root = d; |
1da177e4 LT |
901 | int err; |
902 | ||
903 | sb->s_blocksize = 1024; | |
904 | sb->s_blocksize_bits = 10; | |
905 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
906 | sb->s_op = &hostfs_sbops; | |
752fa51e | 907 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 908 | |
a6eb0be6 | 909 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
910 | if (req_root == NULL) |
911 | req_root = ""; | |
1da177e4 LT |
912 | |
913 | err = -ENOMEM; | |
601d2c38 AV |
914 | sb->s_fs_info = host_root_path = |
915 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 916 | if (host_root_path == NULL) |
1da177e4 LT |
917 | goto out; |
918 | ||
75e8defb | 919 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 920 | |
52b209f7 AV |
921 | root_inode = new_inode(sb); |
922 | if (!root_inode) | |
601d2c38 | 923 | goto out; |
1da177e4 | 924 | |
52b209f7 AV |
925 | root_inode->i_op = &hostfs_dir_iops; |
926 | root_inode->i_fop = &hostfs_dir_fops; | |
927 | ||
928 | if (file_type(host_root_path, NULL, NULL) == OS_TYPE_SYMLINK) { | |
929 | char *name = follow_link(host_root_path); | |
930 | if (IS_ERR(name)) | |
931 | err = PTR_ERR(name); | |
932 | else | |
933 | err = read_name(root_inode, name); | |
934 | kfree(name); | |
935 | } else { | |
936 | err = read_name(root_inode, host_root_path); | |
937 | } | |
84b3db04 | 938 | if (err) |
1da177e4 LT |
939 | goto out_put; |
940 | ||
1da177e4 LT |
941 | err = -ENOMEM; |
942 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 943 | if (sb->s_root == NULL) |
1da177e4 LT |
944 | goto out_put; |
945 | ||
f1adc05e | 946 | return 0; |
1da177e4 | 947 | |
f1adc05e JD |
948 | out_put: |
949 | iput(root_inode); | |
f1adc05e JD |
950 | out: |
951 | return err; | |
1da177e4 LT |
952 | } |
953 | ||
454e2398 DH |
954 | static int hostfs_read_sb(struct file_system_type *type, |
955 | int flags, const char *dev_name, | |
956 | void *data, struct vfsmount *mnt) | |
1da177e4 | 957 | { |
454e2398 | 958 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
959 | } |
960 | ||
601d2c38 AV |
961 | static void hostfs_kill_sb(struct super_block *s) |
962 | { | |
963 | kill_anon_super(s); | |
964 | kfree(s->s_fs_info); | |
965 | } | |
966 | ||
1da177e4 LT |
967 | static struct file_system_type hostfs_type = { |
968 | .owner = THIS_MODULE, | |
969 | .name = "hostfs", | |
970 | .get_sb = hostfs_read_sb, | |
601d2c38 | 971 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
972 | .fs_flags = 0, |
973 | }; | |
974 | ||
975 | static int __init init_hostfs(void) | |
976 | { | |
f1adc05e | 977 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
978 | } |
979 | ||
980 | static void __exit exit_hostfs(void) | |
981 | { | |
982 | unregister_filesystem(&hostfs_type); | |
983 | } | |
984 | ||
985 | module_init(init_hostfs) | |
986 | module_exit(exit_hostfs) | |
987 | MODULE_LICENSE("GPL"); |