Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * ROMFS file system, Linux implementation |
| 3 | * |
| 4 | * Copyright (C) 1997-1999 Janos Farkas <chexum@shadow.banki.hu> |
| 5 | * |
| 6 | * Using parts of the minix filesystem |
| 7 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 8 | * |
| 9 | * and parts of the affs filesystem additionally |
| 10 | * Copyright (C) 1993 Ray Burr |
| 11 | * Copyright (C) 1996 Hans-Joachim Widmaier |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or |
| 14 | * modify it under the terms of the GNU General Public License |
| 15 | * as published by the Free Software Foundation; either version |
| 16 | * 2 of the License, or (at your option) any later version. |
| 17 | * |
| 18 | * Changes |
| 19 | * Changed for 2.1.19 modules |
| 20 | * Jan 1997 Initial release |
| 21 | * Jun 1997 2.1.43+ changes |
| 22 | * Proper page locking in readpage |
| 23 | * Changed to work with 2.1.45+ fs |
| 24 | * Jul 1997 Fixed follow_link |
| 25 | * 2.1.47 |
| 26 | * lookup shouldn't return -ENOENT |
| 27 | * from Horst von Brand: |
| 28 | * fail on wrong checksum |
| 29 | * double unlock_super was possible |
| 30 | * correct namelen for statfs |
| 31 | * spotted by Bill Hawes: |
| 32 | * readlink shouldn't iput() |
| 33 | * Jun 1998 2.1.106 from Avery Pennarun: glibc scandir() |
| 34 | * exposed a problem in readdir |
| 35 | * 2.1.107 code-freeze spellchecker run |
| 36 | * Aug 1998 2.1.118+ VFS changes |
| 37 | * Sep 1998 2.1.122 another VFS change (follow_link) |
| 38 | * Apr 1999 2.2.7 no more EBADF checking in |
| 39 | * lookup/readdir, use ERR_PTR |
| 40 | * Jun 1999 2.3.6 d_alloc_root use changed |
| 41 | * 2.3.9 clean up usage of ENOENT/negative |
| 42 | * dentries in lookup |
| 43 | * clean up page flags setting |
| 44 | * (error, uptodate, locking) in |
| 45 | * in readpage |
| 46 | * use init_special_inode for |
| 47 | * fifos/sockets (and streamline) in |
| 48 | * read_inode, fix _ops table order |
| 49 | * Aug 1999 2.3.16 __initfunc() => __init change |
| 50 | * Oct 1999 2.3.24 page->owner hack obsoleted |
| 51 | * Nov 1999 2.3.27 2.3.25+ page->offset => index change |
| 52 | */ |
| 53 | |
| 54 | /* todo: |
| 55 | * - see Documentation/filesystems/romfs.txt |
| 56 | * - use allocated, not stack memory for file names? |
| 57 | * - considering write access... |
| 58 | * - network (tftp) files? |
| 59 | * - merge back some _op tables |
| 60 | */ |
| 61 | |
| 62 | /* |
| 63 | * Sorry about some optimizations and for some goto's. I just wanted |
| 64 | * to squeeze some more bytes out of this code.. :) |
| 65 | */ |
| 66 | |
| 67 | #include <linux/module.h> |
| 68 | #include <linux/types.h> |
| 69 | #include <linux/errno.h> |
| 70 | #include <linux/slab.h> |
| 71 | #include <linux/romfs_fs.h> |
| 72 | #include <linux/fs.h> |
| 73 | #include <linux/init.h> |
| 74 | #include <linux/pagemap.h> |
| 75 | #include <linux/smp_lock.h> |
| 76 | #include <linux/buffer_head.h> |
| 77 | #include <linux/vfs.h> |
| 78 | |
| 79 | #include <asm/uaccess.h> |
| 80 | |
| 81 | struct romfs_inode_info { |
| 82 | unsigned long i_metasize; /* size of non-data area */ |
| 83 | unsigned long i_dataoffset; /* from the start of fs */ |
| 84 | struct inode vfs_inode; |
| 85 | }; |
| 86 | |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 87 | static struct inode *romfs_iget(struct super_block *, unsigned long); |
| 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | /* instead of private superblock data */ |
| 90 | static inline unsigned long romfs_maxsize(struct super_block *sb) |
| 91 | { |
| 92 | return (unsigned long)sb->s_fs_info; |
| 93 | } |
| 94 | |
| 95 | static inline struct romfs_inode_info *ROMFS_I(struct inode *inode) |
| 96 | { |
WANG Cong | 55ca3e7 | 2007-10-16 23:26:15 -0700 | [diff] [blame] | 97 | return container_of(inode, struct romfs_inode_info, vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | static __u32 |
| 101 | romfs_checksum(void *data, int size) |
| 102 | { |
| 103 | __u32 sum; |
| 104 | __be32 *ptr; |
| 105 | |
| 106 | sum = 0; ptr = data; |
| 107 | size>>=2; |
| 108 | while (size>0) { |
| 109 | sum += be32_to_cpu(*ptr++); |
| 110 | size--; |
| 111 | } |
| 112 | return sum; |
| 113 | } |
| 114 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 115 | static const struct super_operations romfs_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
| 117 | static int romfs_fill_super(struct super_block *s, void *data, int silent) |
| 118 | { |
| 119 | struct buffer_head *bh; |
| 120 | struct romfs_super_block *rsb; |
| 121 | struct inode *root; |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 122 | int sz, ret = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | |
| 124 | /* I would parse the options here, but there are none.. :) */ |
| 125 | |
| 126 | sb_set_blocksize(s, ROMBSIZE); |
| 127 | s->s_maxbytes = 0xFFFFFFFF; |
| 128 | |
| 129 | bh = sb_bread(s, 0); |
| 130 | if (!bh) { |
| 131 | /* XXX merge with other printk? */ |
| 132 | printk ("romfs: unable to read superblock\n"); |
| 133 | goto outnobh; |
| 134 | } |
| 135 | |
| 136 | rsb = (struct romfs_super_block *)bh->b_data; |
| 137 | sz = be32_to_cpu(rsb->size); |
| 138 | if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 |
| 139 | || sz < ROMFH_SIZE) { |
| 140 | if (!silent) |
| 141 | printk ("VFS: Can't find a romfs filesystem on dev " |
| 142 | "%s.\n", s->s_id); |
| 143 | goto out; |
| 144 | } |
| 145 | if (romfs_checksum(rsb, min_t(int, sz, 512))) { |
| 146 | printk ("romfs: bad initial checksum on dev " |
| 147 | "%s.\n", s->s_id); |
| 148 | goto out; |
| 149 | } |
| 150 | |
| 151 | s->s_magic = ROMFS_MAGIC; |
| 152 | s->s_fs_info = (void *)(long)sz; |
| 153 | |
| 154 | s->s_flags |= MS_RDONLY; |
| 155 | |
| 156 | /* Find the start of the fs */ |
| 157 | sz = (ROMFH_SIZE + |
| 158 | strnlen(rsb->name, ROMFS_MAXFN) + 1 + ROMFH_PAD) |
| 159 | & ROMFH_MASK; |
| 160 | |
| 161 | s->s_op = &romfs_ops; |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 162 | root = romfs_iget(s, sz); |
| 163 | if (IS_ERR(root)) { |
| 164 | ret = PTR_ERR(root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | goto out; |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 166 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 168 | ret = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | s->s_root = d_alloc_root(root); |
| 170 | if (!s->s_root) |
| 171 | goto outiput; |
| 172 | |
| 173 | brelse(bh); |
| 174 | return 0; |
| 175 | |
| 176 | outiput: |
| 177 | iput(root); |
| 178 | out: |
| 179 | brelse(bh); |
| 180 | outnobh: |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 181 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | } |
| 183 | |
| 184 | /* That's simple too. */ |
| 185 | |
| 186 | static int |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 187 | romfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | { |
| 189 | buf->f_type = ROMFS_MAGIC; |
| 190 | buf->f_bsize = ROMBSIZE; |
| 191 | buf->f_bfree = buf->f_bavail = buf->f_ffree; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 192 | buf->f_blocks = (romfs_maxsize(dentry->d_sb)+ROMBSIZE-1)>>ROMBSBITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | buf->f_namelen = ROMFS_MAXFN; |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | /* some helper routines */ |
| 198 | |
| 199 | static int |
| 200 | romfs_strnlen(struct inode *i, unsigned long offset, unsigned long count) |
| 201 | { |
| 202 | struct buffer_head *bh; |
| 203 | unsigned long avail, maxsize, res; |
| 204 | |
| 205 | maxsize = romfs_maxsize(i->i_sb); |
| 206 | if (offset >= maxsize) |
| 207 | return -1; |
| 208 | |
| 209 | /* strnlen is almost always valid */ |
| 210 | if (count > maxsize || offset+count > maxsize) |
| 211 | count = maxsize-offset; |
| 212 | |
| 213 | bh = sb_bread(i->i_sb, offset>>ROMBSBITS); |
| 214 | if (!bh) |
| 215 | return -1; /* error */ |
| 216 | |
| 217 | avail = ROMBSIZE - (offset & ROMBMASK); |
| 218 | maxsize = min_t(unsigned long, count, avail); |
| 219 | res = strnlen(((char *)bh->b_data)+(offset&ROMBMASK), maxsize); |
| 220 | brelse(bh); |
| 221 | |
| 222 | if (res < maxsize) |
| 223 | return res; /* found all of it */ |
| 224 | |
| 225 | while (res < count) { |
| 226 | offset += maxsize; |
| 227 | |
| 228 | bh = sb_bread(i->i_sb, offset>>ROMBSBITS); |
| 229 | if (!bh) |
| 230 | return -1; |
| 231 | maxsize = min_t(unsigned long, count - res, ROMBSIZE); |
| 232 | avail = strnlen(bh->b_data, maxsize); |
| 233 | res += avail; |
| 234 | brelse(bh); |
| 235 | if (avail < maxsize) |
| 236 | return res; |
| 237 | } |
| 238 | return res; |
| 239 | } |
| 240 | |
| 241 | static int |
| 242 | romfs_copyfrom(struct inode *i, void *dest, unsigned long offset, unsigned long count) |
| 243 | { |
| 244 | struct buffer_head *bh; |
| 245 | unsigned long avail, maxsize, res; |
| 246 | |
| 247 | maxsize = romfs_maxsize(i->i_sb); |
| 248 | if (offset >= maxsize || count > maxsize || offset+count>maxsize) |
| 249 | return -1; |
| 250 | |
| 251 | bh = sb_bread(i->i_sb, offset>>ROMBSBITS); |
| 252 | if (!bh) |
| 253 | return -1; /* error */ |
| 254 | |
| 255 | avail = ROMBSIZE - (offset & ROMBMASK); |
| 256 | maxsize = min_t(unsigned long, count, avail); |
| 257 | memcpy(dest, ((char *)bh->b_data) + (offset & ROMBMASK), maxsize); |
| 258 | brelse(bh); |
| 259 | |
| 260 | res = maxsize; /* all of it */ |
| 261 | |
| 262 | while (res < count) { |
| 263 | offset += maxsize; |
| 264 | dest += maxsize; |
| 265 | |
| 266 | bh = sb_bread(i->i_sb, offset>>ROMBSBITS); |
| 267 | if (!bh) |
| 268 | return -1; |
| 269 | maxsize = min_t(unsigned long, count - res, ROMBSIZE); |
| 270 | memcpy(dest, bh->b_data, maxsize); |
| 271 | brelse(bh); |
| 272 | res += maxsize; |
| 273 | } |
| 274 | return res; |
| 275 | } |
| 276 | |
| 277 | static unsigned char romfs_dtype_table[] = { |
| 278 | DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO |
| 279 | }; |
| 280 | |
| 281 | static int |
| 282 | romfs_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| 283 | { |
Josef Sipek | 3027795 | 2006-12-08 02:37:34 -0800 | [diff] [blame] | 284 | struct inode *i = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | struct romfs_inode ri; |
| 286 | unsigned long offset, maxoff; |
| 287 | int j, ino, nextfh; |
| 288 | int stored = 0; |
| 289 | char fsname[ROMFS_MAXFN]; /* XXX dynamic? */ |
| 290 | |
| 291 | lock_kernel(); |
| 292 | |
| 293 | maxoff = romfs_maxsize(i->i_sb); |
| 294 | |
| 295 | offset = filp->f_pos; |
| 296 | if (!offset) { |
| 297 | offset = i->i_ino & ROMFH_MASK; |
| 298 | if (romfs_copyfrom(i, &ri, offset, ROMFH_SIZE) <= 0) |
| 299 | goto out; |
| 300 | offset = be32_to_cpu(ri.spec) & ROMFH_MASK; |
| 301 | } |
| 302 | |
| 303 | /* Not really failsafe, but we are read-only... */ |
| 304 | for(;;) { |
| 305 | if (!offset || offset >= maxoff) { |
| 306 | offset = maxoff; |
| 307 | filp->f_pos = offset; |
| 308 | goto out; |
| 309 | } |
| 310 | filp->f_pos = offset; |
| 311 | |
| 312 | /* Fetch inode info */ |
| 313 | if (romfs_copyfrom(i, &ri, offset, ROMFH_SIZE) <= 0) |
| 314 | goto out; |
| 315 | |
| 316 | j = romfs_strnlen(i, offset+ROMFH_SIZE, sizeof(fsname)-1); |
| 317 | if (j < 0) |
| 318 | goto out; |
| 319 | |
| 320 | fsname[j]=0; |
| 321 | romfs_copyfrom(i, fsname, offset+ROMFH_SIZE, j); |
| 322 | |
| 323 | ino = offset; |
| 324 | nextfh = be32_to_cpu(ri.next); |
| 325 | if ((nextfh & ROMFH_TYPE) == ROMFH_HRD) |
| 326 | ino = be32_to_cpu(ri.spec); |
| 327 | if (filldir(dirent, fsname, j, offset, ino, |
| 328 | romfs_dtype_table[nextfh & ROMFH_TYPE]) < 0) { |
| 329 | goto out; |
| 330 | } |
| 331 | stored++; |
| 332 | offset = nextfh & ROMFH_MASK; |
| 333 | } |
| 334 | out: |
| 335 | unlock_kernel(); |
| 336 | return stored; |
| 337 | } |
| 338 | |
| 339 | static struct dentry * |
| 340 | romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) |
| 341 | { |
| 342 | unsigned long offset, maxoff; |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 343 | long res; |
| 344 | int fslen; |
| 345 | struct inode *inode = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | char fsname[ROMFS_MAXFN]; /* XXX dynamic? */ |
| 347 | struct romfs_inode ri; |
| 348 | const char *name; /* got from dentry */ |
| 349 | int len; |
| 350 | |
| 351 | res = -EACCES; /* placeholder for "no data here" */ |
| 352 | offset = dir->i_ino & ROMFH_MASK; |
| 353 | lock_kernel(); |
| 354 | if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0) |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 355 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | |
| 357 | maxoff = romfs_maxsize(dir->i_sb); |
| 358 | offset = be32_to_cpu(ri.spec) & ROMFH_MASK; |
| 359 | |
| 360 | /* OK, now find the file whose name is in "dentry" in the |
| 361 | * directory specified by "dir". */ |
| 362 | |
| 363 | name = dentry->d_name.name; |
| 364 | len = dentry->d_name.len; |
| 365 | |
| 366 | for(;;) { |
| 367 | if (!offset || offset >= maxoff) |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 368 | goto success; /* negative success */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0) |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 370 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
| 372 | /* try to match the first 16 bytes of name */ |
| 373 | fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, ROMFH_SIZE); |
| 374 | if (len < ROMFH_SIZE) { |
| 375 | if (len == fslen) { |
| 376 | /* both are shorter, and same size */ |
| 377 | romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1); |
| 378 | if (strncmp (name, fsname, len) == 0) |
| 379 | break; |
| 380 | } |
| 381 | } else if (fslen >= ROMFH_SIZE) { |
| 382 | /* both are longer; XXX optimize max size */ |
| 383 | fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, sizeof(fsname)-1); |
| 384 | if (len == fslen) { |
| 385 | romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1); |
| 386 | if (strncmp(name, fsname, len) == 0) |
| 387 | break; |
| 388 | } |
| 389 | } |
| 390 | /* next entry */ |
| 391 | offset = be32_to_cpu(ri.next) & ROMFH_MASK; |
| 392 | } |
| 393 | |
| 394 | /* Hard link handling */ |
| 395 | if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD) |
| 396 | offset = be32_to_cpu(ri.spec) & ROMFH_MASK; |
| 397 | |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 398 | inode = romfs_iget(dir->i_sb, offset); |
| 399 | if (IS_ERR(inode)) { |
| 400 | res = PTR_ERR(inode); |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 401 | goto error; |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 402 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 404 | success: |
| 405 | d_add(dentry, inode); |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 406 | res = 0; |
David Howells | 4ebf898 | 2008-03-19 17:00:50 -0700 | [diff] [blame] | 407 | error: |
| 408 | unlock_kernel(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | return ERR_PTR(res); |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * Ok, we do readpage, to be able to execute programs. Unfortunately, |
| 414 | * we can't use bmap, since we may have looser alignments. |
| 415 | */ |
| 416 | |
| 417 | static int |
| 418 | romfs_readpage(struct file *file, struct page * page) |
| 419 | { |
| 420 | struct inode *inode = page->mapping->host; |
Andrew Morton | 54b21a7 | 2006-01-08 01:03:05 -0800 | [diff] [blame] | 421 | loff_t offset, avail, readlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | void *buf; |
| 423 | int result = -EIO; |
| 424 | |
| 425 | page_cache_get(page); |
| 426 | lock_kernel(); |
| 427 | buf = kmap(page); |
| 428 | if (!buf) |
| 429 | goto err_out; |
| 430 | |
| 431 | /* 32 bit warning -- but not for us :) */ |
Andrew Morton | 54b21a7 | 2006-01-08 01:03:05 -0800 | [diff] [blame] | 432 | offset = page_offset(page); |
| 433 | if (offset < i_size_read(inode)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | avail = inode->i_size-offset; |
| 435 | readlen = min_t(unsigned long, avail, PAGE_SIZE); |
| 436 | if (romfs_copyfrom(inode, buf, ROMFS_I(inode)->i_dataoffset+offset, readlen) == readlen) { |
| 437 | if (readlen < PAGE_SIZE) { |
| 438 | memset(buf + readlen,0,PAGE_SIZE-readlen); |
| 439 | } |
| 440 | SetPageUptodate(page); |
| 441 | result = 0; |
| 442 | } |
| 443 | } |
| 444 | if (result) { |
| 445 | memset(buf, 0, PAGE_SIZE); |
| 446 | SetPageError(page); |
| 447 | } |
| 448 | flush_dcache_page(page); |
| 449 | |
| 450 | unlock_page(page); |
| 451 | |
| 452 | kunmap(page); |
| 453 | err_out: |
| 454 | page_cache_release(page); |
| 455 | unlock_kernel(); |
| 456 | |
| 457 | return result; |
| 458 | } |
| 459 | |
| 460 | /* Mapping from our types to the kernel */ |
| 461 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 462 | static const struct address_space_operations romfs_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | .readpage = romfs_readpage |
| 464 | }; |
| 465 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 466 | static const struct file_operations romfs_dir_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | .read = generic_read_dir, |
| 468 | .readdir = romfs_readdir, |
| 469 | }; |
| 470 | |
Arjan van de Ven | c5ef1c4 | 2007-02-12 00:55:40 -0800 | [diff] [blame] | 471 | static const struct inode_operations romfs_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | .lookup = romfs_lookup, |
| 473 | }; |
| 474 | |
| 475 | static mode_t romfs_modemap[] = |
| 476 | { |
| 477 | 0, S_IFDIR+0644, S_IFREG+0644, S_IFLNK+0777, |
| 478 | S_IFBLK+0600, S_IFCHR+0600, S_IFSOCK+0644, S_IFIFO+0644 |
| 479 | }; |
| 480 | |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 481 | static struct inode * |
| 482 | romfs_iget(struct super_block *sb, unsigned long ino) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | { |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 484 | int nextfh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | struct romfs_inode ri; |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 486 | struct inode *i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 488 | ino &= ROMFH_MASK; |
| 489 | i = iget_locked(sb, ino); |
| 490 | if (!i) |
| 491 | return ERR_PTR(-ENOMEM); |
| 492 | if (!(i->i_state & I_NEW)) |
| 493 | return i; |
| 494 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | i->i_mode = 0; |
| 496 | |
| 497 | /* Loop for finding the real hard link */ |
| 498 | for(;;) { |
| 499 | if (romfs_copyfrom(i, &ri, ino, ROMFH_SIZE) <= 0) { |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 500 | printk(KERN_ERR "romfs: read error for inode 0x%lx\n", |
| 501 | ino); |
| 502 | iget_failed(i); |
| 503 | return ERR_PTR(-EIO); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | } |
| 505 | /* XXX: do romfs_checksum here too (with name) */ |
| 506 | |
| 507 | nextfh = be32_to_cpu(ri.next); |
| 508 | if ((nextfh & ROMFH_TYPE) != ROMFH_HRD) |
| 509 | break; |
| 510 | |
| 511 | ino = be32_to_cpu(ri.spec) & ROMFH_MASK; |
| 512 | } |
| 513 | |
| 514 | i->i_nlink = 1; /* Hard to decide.. */ |
| 515 | i->i_size = be32_to_cpu(ri.size); |
| 516 | i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0; |
| 517 | i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0; |
| 518 | i->i_uid = i->i_gid = 0; |
| 519 | |
| 520 | /* Precalculate the data offset */ |
| 521 | ino = romfs_strnlen(i, ino+ROMFH_SIZE, ROMFS_MAXFN); |
| 522 | if (ino >= 0) |
| 523 | ino = ((ROMFH_SIZE+ino+1+ROMFH_PAD)&ROMFH_MASK); |
| 524 | else |
| 525 | ino = 0; |
| 526 | |
| 527 | ROMFS_I(i)->i_metasize = ino; |
| 528 | ROMFS_I(i)->i_dataoffset = ino+(i->i_ino&ROMFH_MASK); |
| 529 | |
| 530 | /* Compute permissions */ |
| 531 | ino = romfs_modemap[nextfh & ROMFH_TYPE]; |
| 532 | /* only "normal" files have ops */ |
| 533 | switch (nextfh & ROMFH_TYPE) { |
| 534 | case 1: |
| 535 | i->i_size = ROMFS_I(i)->i_metasize; |
| 536 | i->i_op = &romfs_dir_inode_operations; |
| 537 | i->i_fop = &romfs_dir_operations; |
| 538 | if (nextfh & ROMFH_EXEC) |
| 539 | ino |= S_IXUGO; |
| 540 | i->i_mode = ino; |
| 541 | break; |
| 542 | case 2: |
| 543 | i->i_fop = &generic_ro_fops; |
| 544 | i->i_data.a_ops = &romfs_aops; |
| 545 | if (nextfh & ROMFH_EXEC) |
| 546 | ino |= S_IXUGO; |
| 547 | i->i_mode = ino; |
| 548 | break; |
| 549 | case 3: |
| 550 | i->i_op = &page_symlink_inode_operations; |
| 551 | i->i_data.a_ops = &romfs_aops; |
| 552 | i->i_mode = ino | S_IRWXUGO; |
| 553 | break; |
| 554 | default: |
| 555 | /* depending on MBZ for sock/fifos */ |
| 556 | nextfh = be32_to_cpu(ri.spec); |
| 557 | init_special_inode(i, ino, |
| 558 | MKDEV(nextfh>>16,nextfh&0xffff)); |
| 559 | } |
David Howells | 78cc912 | 2008-02-07 00:15:46 -0800 | [diff] [blame] | 560 | unlock_new_inode(i); |
| 561 | return i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | } |
| 563 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 564 | static struct kmem_cache * romfs_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | |
| 566 | static struct inode *romfs_alloc_inode(struct super_block *sb) |
| 567 | { |
| 568 | struct romfs_inode_info *ei; |
WANG Cong | 55ca3e7 | 2007-10-16 23:26:15 -0700 | [diff] [blame] | 569 | ei = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | if (!ei) |
| 571 | return NULL; |
| 572 | return &ei->vfs_inode; |
| 573 | } |
| 574 | |
| 575 | static void romfs_destroy_inode(struct inode *inode) |
| 576 | { |
| 577 | kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode)); |
| 578 | } |
| 579 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 580 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | { |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 582 | struct romfs_inode_info *ei = foo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 584 | inode_init_once(&ei->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | } |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 586 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | static int init_inodecache(void) |
| 588 | { |
| 589 | romfs_inode_cachep = kmem_cache_create("romfs_inode_cache", |
| 590 | sizeof(struct romfs_inode_info), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 591 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 592 | SLAB_MEM_SPREAD), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 593 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | if (romfs_inode_cachep == NULL) |
| 595 | return -ENOMEM; |
| 596 | return 0; |
| 597 | } |
| 598 | |
| 599 | static void destroy_inodecache(void) |
| 600 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 601 | kmem_cache_destroy(romfs_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | } |
| 603 | |
| 604 | static int romfs_remount(struct super_block *sb, int *flags, char *data) |
| 605 | { |
| 606 | *flags |= MS_RDONLY; |
| 607 | return 0; |
| 608 | } |
| 609 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 610 | static const struct super_operations romfs_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | .alloc_inode = romfs_alloc_inode, |
| 612 | .destroy_inode = romfs_destroy_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | .statfs = romfs_statfs, |
| 614 | .remount_fs = romfs_remount, |
| 615 | }; |
| 616 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 617 | static int romfs_get_sb(struct file_system_type *fs_type, |
| 618 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 620 | return get_sb_bdev(fs_type, flags, dev_name, data, romfs_fill_super, |
| 621 | mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | } |
| 623 | |
| 624 | static struct file_system_type romfs_fs_type = { |
| 625 | .owner = THIS_MODULE, |
| 626 | .name = "romfs", |
| 627 | .get_sb = romfs_get_sb, |
| 628 | .kill_sb = kill_block_super, |
| 629 | .fs_flags = FS_REQUIRES_DEV, |
| 630 | }; |
| 631 | |
| 632 | static int __init init_romfs_fs(void) |
| 633 | { |
| 634 | int err = init_inodecache(); |
| 635 | if (err) |
| 636 | goto out1; |
| 637 | err = register_filesystem(&romfs_fs_type); |
| 638 | if (err) |
| 639 | goto out; |
| 640 | return 0; |
| 641 | out: |
| 642 | destroy_inodecache(); |
| 643 | out1: |
| 644 | return err; |
| 645 | } |
| 646 | |
| 647 | static void __exit exit_romfs_fs(void) |
| 648 | { |
| 649 | unregister_filesystem(&romfs_fs_type); |
| 650 | destroy_inodecache(); |
| 651 | } |
| 652 | |
| 653 | /* Yes, works even as a module... :) */ |
| 654 | |
| 655 | module_init(init_romfs_fs) |
| 656 | module_exit(exit_romfs_fs) |
| 657 | MODULE_LICENSE("GPL"); |