xref: /openbmc/linux/fs/jffs2/fs.c (revision e23feb16)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by David Woodhouse <dwmw2@infradead.org>
8  *
9  * For licensing information, see the file 'LICENCE' in this directory.
10  *
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/capability.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/fs.h>
19 #include <linux/list.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/pagemap.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/vfs.h>
25 #include <linux/crc32.h>
26 #include "nodelist.h"
27 
28 static int jffs2_flash_setup(struct jffs2_sb_info *c);
29 
30 int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
31 {
32 	struct jffs2_full_dnode *old_metadata, *new_metadata;
33 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
34 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
35 	struct jffs2_raw_inode *ri;
36 	union jffs2_device_node dev;
37 	unsigned char *mdata = NULL;
38 	int mdatalen = 0;
39 	unsigned int ivalid;
40 	uint32_t alloclen;
41 	int ret;
42 	int alloc_type = ALLOC_NORMAL;
43 
44 	jffs2_dbg(1, "%s(): ino #%lu\n", __func__, inode->i_ino);
45 
46 	/* Special cases - we don't want more than one data node
47 	   for these types on the medium at any time. So setattr
48 	   must read the original data associated with the node
49 	   (i.e. the device numbers or the target name) and write
50 	   it out again with the appropriate data attached */
51 	if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
52 		/* For these, we don't actually need to read the old node */
53 		mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
54 		mdata = (char *)&dev;
55 		jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
56 			  __func__, mdatalen);
57 	} else if (S_ISLNK(inode->i_mode)) {
58 		mutex_lock(&f->sem);
59 		mdatalen = f->metadata->size;
60 		mdata = kmalloc(f->metadata->size, GFP_USER);
61 		if (!mdata) {
62 			mutex_unlock(&f->sem);
63 			return -ENOMEM;
64 		}
65 		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
66 		if (ret) {
67 			mutex_unlock(&f->sem);
68 			kfree(mdata);
69 			return ret;
70 		}
71 		mutex_unlock(&f->sem);
72 		jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
73 			  __func__, mdatalen);
74 	}
75 
76 	ri = jffs2_alloc_raw_inode();
77 	if (!ri) {
78 		if (S_ISLNK(inode->i_mode))
79 			kfree(mdata);
80 		return -ENOMEM;
81 	}
82 
83 	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
84 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
85 	if (ret) {
86 		jffs2_free_raw_inode(ri);
87 		if (S_ISLNK(inode->i_mode))
88 			 kfree(mdata);
89 		return ret;
90 	}
91 	mutex_lock(&f->sem);
92 	ivalid = iattr->ia_valid;
93 
94 	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
95 	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
96 	ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
97 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
98 
99 	ri->ino = cpu_to_je32(inode->i_ino);
100 	ri->version = cpu_to_je32(++f->highest_version);
101 
102 	ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
103 		from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
104 	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
105 		from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
106 
107 	if (ivalid & ATTR_MODE)
108 		ri->mode = cpu_to_jemode(iattr->ia_mode);
109 	else
110 		ri->mode = cpu_to_jemode(inode->i_mode);
111 
112 
113 	ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
114 	ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
115 	ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
116 	ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));
117 
118 	ri->offset = cpu_to_je32(0);
119 	ri->csize = ri->dsize = cpu_to_je32(mdatalen);
120 	ri->compr = JFFS2_COMPR_NONE;
121 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
122 		/* It's an extension. Make it a hole node */
123 		ri->compr = JFFS2_COMPR_ZERO;
124 		ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
125 		ri->offset = cpu_to_je32(inode->i_size);
126 	} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
127 		/* For truncate-to-zero, treat it as deletion because
128 		   it'll always be obsoleting all previous nodes */
129 		alloc_type = ALLOC_DELETION;
130 	}
131 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
132 	if (mdatalen)
133 		ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
134 	else
135 		ri->data_crc = cpu_to_je32(0);
136 
137 	new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
138 	if (S_ISLNK(inode->i_mode))
139 		kfree(mdata);
140 
141 	if (IS_ERR(new_metadata)) {
142 		jffs2_complete_reservation(c);
143 		jffs2_free_raw_inode(ri);
144 		mutex_unlock(&f->sem);
145 		return PTR_ERR(new_metadata);
146 	}
147 	/* It worked. Update the inode */
148 	inode->i_atime = ITIME(je32_to_cpu(ri->atime));
149 	inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
150 	inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
151 	inode->i_mode = jemode_to_cpu(ri->mode);
152 	i_uid_write(inode, je16_to_cpu(ri->uid));
153 	i_gid_write(inode, je16_to_cpu(ri->gid));
154 
155 
156 	old_metadata = f->metadata;
157 
158 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
159 		jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
160 
161 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
162 		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
163 		inode->i_size = iattr->ia_size;
164 		inode->i_blocks = (inode->i_size + 511) >> 9;
165 		f->metadata = NULL;
166 	} else {
167 		f->metadata = new_metadata;
168 	}
169 	if (old_metadata) {
170 		jffs2_mark_node_obsolete(c, old_metadata->raw);
171 		jffs2_free_full_dnode(old_metadata);
172 	}
173 	jffs2_free_raw_inode(ri);
174 
175 	mutex_unlock(&f->sem);
176 	jffs2_complete_reservation(c);
177 
178 	/* We have to do the truncate_setsize() without f->sem held, since
179 	   some pages may be locked and waiting for it in readpage().
180 	   We are protected from a simultaneous write() extending i_size
181 	   back past iattr->ia_size, because do_truncate() holds the
182 	   generic inode semaphore. */
183 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
184 		truncate_setsize(inode, iattr->ia_size);
185 		inode->i_blocks = (inode->i_size + 511) >> 9;
186 	}
187 
188 	return 0;
189 }
190 
191 int jffs2_setattr(struct dentry *dentry, struct iattr *iattr)
192 {
193 	int rc;
194 
195 	rc = inode_change_ok(dentry->d_inode, iattr);
196 	if (rc)
197 		return rc;
198 
199 	rc = jffs2_do_setattr(dentry->d_inode, iattr);
200 	if (!rc && (iattr->ia_valid & ATTR_MODE))
201 		rc = jffs2_acl_chmod(dentry->d_inode);
202 
203 	return rc;
204 }
205 
206 int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
207 {
208 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
209 	unsigned long avail;
210 
211 	buf->f_type = JFFS2_SUPER_MAGIC;
212 	buf->f_bsize = 1 << PAGE_SHIFT;
213 	buf->f_blocks = c->flash_size >> PAGE_SHIFT;
214 	buf->f_files = 0;
215 	buf->f_ffree = 0;
216 	buf->f_namelen = JFFS2_MAX_NAME_LEN;
217 	buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
218 	buf->f_fsid.val[1] = c->mtd->index;
219 
220 	spin_lock(&c->erase_completion_lock);
221 	avail = c->dirty_size + c->free_size;
222 	if (avail > c->sector_size * c->resv_blocks_write)
223 		avail -= c->sector_size * c->resv_blocks_write;
224 	else
225 		avail = 0;
226 	spin_unlock(&c->erase_completion_lock);
227 
228 	buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
229 
230 	return 0;
231 }
232 
233 
234 void jffs2_evict_inode (struct inode *inode)
235 {
236 	/* We can forget about this inode for now - drop all
237 	 *  the nodelists associated with it, etc.
238 	 */
239 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
240 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
241 
242 	jffs2_dbg(1, "%s(): ino #%lu mode %o\n",
243 		  __func__, inode->i_ino, inode->i_mode);
244 	truncate_inode_pages(&inode->i_data, 0);
245 	clear_inode(inode);
246 	jffs2_do_clear_inode(c, f);
247 }
248 
249 struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
250 {
251 	struct jffs2_inode_info *f;
252 	struct jffs2_sb_info *c;
253 	struct jffs2_raw_inode latest_node;
254 	union jffs2_device_node jdev;
255 	struct inode *inode;
256 	dev_t rdev = 0;
257 	int ret;
258 
259 	jffs2_dbg(1, "%s(): ino == %lu\n", __func__, ino);
260 
261 	inode = iget_locked(sb, ino);
262 	if (!inode)
263 		return ERR_PTR(-ENOMEM);
264 	if (!(inode->i_state & I_NEW))
265 		return inode;
266 
267 	f = JFFS2_INODE_INFO(inode);
268 	c = JFFS2_SB_INFO(inode->i_sb);
269 
270 	jffs2_init_inode_info(f);
271 	mutex_lock(&f->sem);
272 
273 	ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
274 
275 	if (ret) {
276 		mutex_unlock(&f->sem);
277 		iget_failed(inode);
278 		return ERR_PTR(ret);
279 	}
280 	inode->i_mode = jemode_to_cpu(latest_node.mode);
281 	i_uid_write(inode, je16_to_cpu(latest_node.uid));
282 	i_gid_write(inode, je16_to_cpu(latest_node.gid));
283 	inode->i_size = je32_to_cpu(latest_node.isize);
284 	inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
285 	inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
286 	inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime));
287 
288 	set_nlink(inode, f->inocache->pino_nlink);
289 
290 	inode->i_blocks = (inode->i_size + 511) >> 9;
291 
292 	switch (inode->i_mode & S_IFMT) {
293 
294 	case S_IFLNK:
295 		inode->i_op = &jffs2_symlink_inode_operations;
296 		break;
297 
298 	case S_IFDIR:
299 	{
300 		struct jffs2_full_dirent *fd;
301 		set_nlink(inode, 2); /* parent and '.' */
302 
303 		for (fd=f->dents; fd; fd = fd->next) {
304 			if (fd->type == DT_DIR && fd->ino)
305 				inc_nlink(inode);
306 		}
307 		/* Root dir gets i_nlink 3 for some reason */
308 		if (inode->i_ino == 1)
309 			inc_nlink(inode);
310 
311 		inode->i_op = &jffs2_dir_inode_operations;
312 		inode->i_fop = &jffs2_dir_operations;
313 		break;
314 	}
315 	case S_IFREG:
316 		inode->i_op = &jffs2_file_inode_operations;
317 		inode->i_fop = &jffs2_file_operations;
318 		inode->i_mapping->a_ops = &jffs2_file_address_operations;
319 		inode->i_mapping->nrpages = 0;
320 		break;
321 
322 	case S_IFBLK:
323 	case S_IFCHR:
324 		/* Read the device numbers from the media */
325 		if (f->metadata->size != sizeof(jdev.old_id) &&
326 		    f->metadata->size != sizeof(jdev.new_id)) {
327 			pr_notice("Device node has strange size %d\n",
328 				  f->metadata->size);
329 			goto error_io;
330 		}
331 		jffs2_dbg(1, "Reading device numbers from flash\n");
332 		ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
333 		if (ret < 0) {
334 			/* Eep */
335 			pr_notice("Read device numbers for inode %lu failed\n",
336 				  (unsigned long)inode->i_ino);
337 			goto error;
338 		}
339 		if (f->metadata->size == sizeof(jdev.old_id))
340 			rdev = old_decode_dev(je16_to_cpu(jdev.old_id));
341 		else
342 			rdev = new_decode_dev(je32_to_cpu(jdev.new_id));
343 
344 	case S_IFSOCK:
345 	case S_IFIFO:
346 		inode->i_op = &jffs2_file_inode_operations;
347 		init_special_inode(inode, inode->i_mode, rdev);
348 		break;
349 
350 	default:
351 		pr_warn("%s(): Bogus i_mode %o for ino %lu\n",
352 			__func__, inode->i_mode, (unsigned long)inode->i_ino);
353 	}
354 
355 	mutex_unlock(&f->sem);
356 
357 	jffs2_dbg(1, "jffs2_read_inode() returning\n");
358 	unlock_new_inode(inode);
359 	return inode;
360 
361 error_io:
362 	ret = -EIO;
363 error:
364 	mutex_unlock(&f->sem);
365 	jffs2_do_clear_inode(c, f);
366 	iget_failed(inode);
367 	return ERR_PTR(ret);
368 }
369 
370 void jffs2_dirty_inode(struct inode *inode, int flags)
371 {
372 	struct iattr iattr;
373 
374 	if (!(inode->i_state & I_DIRTY_DATASYNC)) {
375 		jffs2_dbg(2, "%s(): not calling setattr() for ino #%lu\n",
376 			  __func__, inode->i_ino);
377 		return;
378 	}
379 
380 	jffs2_dbg(1, "%s(): calling setattr() for ino #%lu\n",
381 		  __func__, inode->i_ino);
382 
383 	iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
384 	iattr.ia_mode = inode->i_mode;
385 	iattr.ia_uid = inode->i_uid;
386 	iattr.ia_gid = inode->i_gid;
387 	iattr.ia_atime = inode->i_atime;
388 	iattr.ia_mtime = inode->i_mtime;
389 	iattr.ia_ctime = inode->i_ctime;
390 
391 	jffs2_do_setattr(inode, &iattr);
392 }
393 
394 int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
395 {
396 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
397 
398 	if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
399 		return -EROFS;
400 
401 	/* We stop if it was running, then restart if it needs to.
402 	   This also catches the case where it was stopped and this
403 	   is just a remount to restart it.
404 	   Flush the writebuffer, if neccecary, else we loose it */
405 	if (!(sb->s_flags & MS_RDONLY)) {
406 		jffs2_stop_garbage_collect_thread(c);
407 		mutex_lock(&c->alloc_sem);
408 		jffs2_flush_wbuf_pad(c);
409 		mutex_unlock(&c->alloc_sem);
410 	}
411 
412 	if (!(*flags & MS_RDONLY))
413 		jffs2_start_garbage_collect_thread(c);
414 
415 	*flags |= MS_NOATIME;
416 	return 0;
417 }
418 
419 /* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
420    fill in the raw_inode while you're at it. */
421 struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_raw_inode *ri)
422 {
423 	struct inode *inode;
424 	struct super_block *sb = dir_i->i_sb;
425 	struct jffs2_sb_info *c;
426 	struct jffs2_inode_info *f;
427 	int ret;
428 
429 	jffs2_dbg(1, "%s(): dir_i %ld, mode 0x%x\n",
430 		  __func__, dir_i->i_ino, mode);
431 
432 	c = JFFS2_SB_INFO(sb);
433 
434 	inode = new_inode(sb);
435 
436 	if (!inode)
437 		return ERR_PTR(-ENOMEM);
438 
439 	f = JFFS2_INODE_INFO(inode);
440 	jffs2_init_inode_info(f);
441 	mutex_lock(&f->sem);
442 
443 	memset(ri, 0, sizeof(*ri));
444 	/* Set OS-specific defaults for new inodes */
445 	ri->uid = cpu_to_je16(from_kuid(&init_user_ns, current_fsuid()));
446 
447 	if (dir_i->i_mode & S_ISGID) {
448 		ri->gid = cpu_to_je16(i_gid_read(dir_i));
449 		if (S_ISDIR(mode))
450 			mode |= S_ISGID;
451 	} else {
452 		ri->gid = cpu_to_je16(from_kgid(&init_user_ns, current_fsgid()));
453 	}
454 
455 	/* POSIX ACLs have to be processed now, at least partly.
456 	   The umask is only applied if there's no default ACL */
457 	ret = jffs2_init_acl_pre(dir_i, inode, &mode);
458 	if (ret) {
459 	    make_bad_inode(inode);
460 	    iput(inode);
461 	    return ERR_PTR(ret);
462 	}
463 	ret = jffs2_do_new_inode (c, f, mode, ri);
464 	if (ret) {
465 		make_bad_inode(inode);
466 		iput(inode);
467 		return ERR_PTR(ret);
468 	}
469 	set_nlink(inode, 1);
470 	inode->i_ino = je32_to_cpu(ri->ino);
471 	inode->i_mode = jemode_to_cpu(ri->mode);
472 	i_gid_write(inode, je16_to_cpu(ri->gid));
473 	i_uid_write(inode, je16_to_cpu(ri->uid));
474 	inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
475 	ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
476 
477 	inode->i_blocks = 0;
478 	inode->i_size = 0;
479 
480 	if (insert_inode_locked(inode) < 0) {
481 		make_bad_inode(inode);
482 		iput(inode);
483 		return ERR_PTR(-EINVAL);
484 	}
485 
486 	return inode;
487 }
488 
489 static int calculate_inocache_hashsize(uint32_t flash_size)
490 {
491 	/*
492 	 * Pick a inocache hash size based on the size of the medium.
493 	 * Count how many megabytes we're dealing with, apply a hashsize twice
494 	 * that size, but rounding down to the usual big powers of 2. And keep
495 	 * to sensible bounds.
496 	 */
497 
498 	int size_mb = flash_size / 1024 / 1024;
499 	int hashsize = (size_mb * 2) & ~0x3f;
500 
501 	if (hashsize < INOCACHE_HASHSIZE_MIN)
502 		return INOCACHE_HASHSIZE_MIN;
503 	if (hashsize > INOCACHE_HASHSIZE_MAX)
504 		return INOCACHE_HASHSIZE_MAX;
505 
506 	return hashsize;
507 }
508 
509 int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
510 {
511 	struct jffs2_sb_info *c;
512 	struct inode *root_i;
513 	int ret;
514 	size_t blocks;
515 
516 	c = JFFS2_SB_INFO(sb);
517 
518 #ifndef CONFIG_JFFS2_FS_WRITEBUFFER
519 	if (c->mtd->type == MTD_NANDFLASH) {
520 		pr_err("Cannot operate on NAND flash unless jffs2 NAND support is compiled in\n");
521 		return -EINVAL;
522 	}
523 	if (c->mtd->type == MTD_DATAFLASH) {
524 		pr_err("Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in\n");
525 		return -EINVAL;
526 	}
527 #endif
528 
529 	c->flash_size = c->mtd->size;
530 	c->sector_size = c->mtd->erasesize;
531 	blocks = c->flash_size / c->sector_size;
532 
533 	/*
534 	 * Size alignment check
535 	 */
536 	if ((c->sector_size * blocks) != c->flash_size) {
537 		c->flash_size = c->sector_size * blocks;
538 		pr_info("Flash size not aligned to erasesize, reducing to %dKiB\n",
539 			c->flash_size / 1024);
540 	}
541 
542 	if (c->flash_size < 5*c->sector_size) {
543 		pr_err("Too few erase blocks (%d)\n",
544 		       c->flash_size / c->sector_size);
545 		return -EINVAL;
546 	}
547 
548 	c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
549 
550 	/* NAND (or other bizarre) flash... do setup accordingly */
551 	ret = jffs2_flash_setup(c);
552 	if (ret)
553 		return ret;
554 
555 	c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size);
556 	c->inocache_list = kcalloc(c->inocache_hashsize, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
557 	if (!c->inocache_list) {
558 		ret = -ENOMEM;
559 		goto out_wbuf;
560 	}
561 
562 	jffs2_init_xattr_subsystem(c);
563 
564 	if ((ret = jffs2_do_mount_fs(c)))
565 		goto out_inohash;
566 
567 	jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
568 	root_i = jffs2_iget(sb, 1);
569 	if (IS_ERR(root_i)) {
570 		jffs2_dbg(1, "get root inode failed\n");
571 		ret = PTR_ERR(root_i);
572 		goto out_root;
573 	}
574 
575 	ret = -ENOMEM;
576 
577 	jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
578 	sb->s_root = d_make_root(root_i);
579 	if (!sb->s_root)
580 		goto out_root;
581 
582 	sb->s_maxbytes = 0xFFFFFFFF;
583 	sb->s_blocksize = PAGE_CACHE_SIZE;
584 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
585 	sb->s_magic = JFFS2_SUPER_MAGIC;
586 	if (!(sb->s_flags & MS_RDONLY))
587 		jffs2_start_garbage_collect_thread(c);
588 	return 0;
589 
590 out_root:
591 	jffs2_free_ino_caches(c);
592 	jffs2_free_raw_node_refs(c);
593 	if (jffs2_blocks_use_vmalloc(c))
594 		vfree(c->blocks);
595 	else
596 		kfree(c->blocks);
597  out_inohash:
598 	jffs2_clear_xattr_subsystem(c);
599 	kfree(c->inocache_list);
600  out_wbuf:
601 	jffs2_flash_cleanup(c);
602 
603 	return ret;
604 }
605 
606 void jffs2_gc_release_inode(struct jffs2_sb_info *c,
607 				   struct jffs2_inode_info *f)
608 {
609 	iput(OFNI_EDONI_2SFFJ(f));
610 }
611 
612 struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
613 					      int inum, int unlinked)
614 {
615 	struct inode *inode;
616 	struct jffs2_inode_cache *ic;
617 
618 	if (unlinked) {
619 		/* The inode has zero nlink but its nodes weren't yet marked
620 		   obsolete. This has to be because we're still waiting for
621 		   the final (close() and) iput() to happen.
622 
623 		   There's a possibility that the final iput() could have
624 		   happened while we were contemplating. In order to ensure
625 		   that we don't cause a new read_inode() (which would fail)
626 		   for the inode in question, we use ilookup() in this case
627 		   instead of iget().
628 
629 		   The nlink can't _become_ zero at this point because we're
630 		   holding the alloc_sem, and jffs2_do_unlink() would also
631 		   need that while decrementing nlink on any inode.
632 		*/
633 		inode = ilookup(OFNI_BS_2SFFJ(c), inum);
634 		if (!inode) {
635 			jffs2_dbg(1, "ilookup() failed for ino #%u; inode is probably deleted.\n",
636 				  inum);
637 
638 			spin_lock(&c->inocache_lock);
639 			ic = jffs2_get_ino_cache(c, inum);
640 			if (!ic) {
641 				jffs2_dbg(1, "Inode cache for ino #%u is gone\n",
642 					  inum);
643 				spin_unlock(&c->inocache_lock);
644 				return NULL;
645 			}
646 			if (ic->state != INO_STATE_CHECKEDABSENT) {
647 				/* Wait for progress. Don't just loop */
648 				jffs2_dbg(1, "Waiting for ino #%u in state %d\n",
649 					  ic->ino, ic->state);
650 				sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
651 			} else {
652 				spin_unlock(&c->inocache_lock);
653 			}
654 
655 			return NULL;
656 		}
657 	} else {
658 		/* Inode has links to it still; they're not going away because
659 		   jffs2_do_unlink() would need the alloc_sem and we have it.
660 		   Just iget() it, and if read_inode() is necessary that's OK.
661 		*/
662 		inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
663 		if (IS_ERR(inode))
664 			return ERR_CAST(inode);
665 	}
666 	if (is_bad_inode(inode)) {
667 		pr_notice("Eep. read_inode() failed for ino #%u. unlinked %d\n",
668 			  inum, unlinked);
669 		/* NB. This will happen again. We need to do something appropriate here. */
670 		iput(inode);
671 		return ERR_PTR(-EIO);
672 	}
673 
674 	return JFFS2_INODE_INFO(inode);
675 }
676 
677 unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c,
678 				   struct jffs2_inode_info *f,
679 				   unsigned long offset,
680 				   unsigned long *priv)
681 {
682 	struct inode *inode = OFNI_EDONI_2SFFJ(f);
683 	struct page *pg;
684 
685 	pg = read_cache_page_async(inode->i_mapping, offset >> PAGE_CACHE_SHIFT,
686 			     (void *)jffs2_do_readpage_unlock, inode);
687 	if (IS_ERR(pg))
688 		return (void *)pg;
689 
690 	*priv = (unsigned long)pg;
691 	return kmap(pg);
692 }
693 
694 void jffs2_gc_release_page(struct jffs2_sb_info *c,
695 			   unsigned char *ptr,
696 			   unsigned long *priv)
697 {
698 	struct page *pg = (void *)*priv;
699 
700 	kunmap(pg);
701 	page_cache_release(pg);
702 }
703 
704 static int jffs2_flash_setup(struct jffs2_sb_info *c) {
705 	int ret = 0;
706 
707 	if (jffs2_cleanmarker_oob(c)) {
708 		/* NAND flash... do setup accordingly */
709 		ret = jffs2_nand_flash_setup(c);
710 		if (ret)
711 			return ret;
712 	}
713 
714 	/* and Dataflash */
715 	if (jffs2_dataflash(c)) {
716 		ret = jffs2_dataflash_setup(c);
717 		if (ret)
718 			return ret;
719 	}
720 
721 	/* and Intel "Sibley" flash */
722 	if (jffs2_nor_wbuf_flash(c)) {
723 		ret = jffs2_nor_wbuf_flash_setup(c);
724 		if (ret)
725 			return ret;
726 	}
727 
728 	/* and an UBI volume */
729 	if (jffs2_ubivol(c)) {
730 		ret = jffs2_ubivol_setup(c);
731 		if (ret)
732 			return ret;
733 	}
734 
735 	return ret;
736 }
737 
738 void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
739 
740 	if (jffs2_cleanmarker_oob(c)) {
741 		jffs2_nand_flash_cleanup(c);
742 	}
743 
744 	/* and DataFlash */
745 	if (jffs2_dataflash(c)) {
746 		jffs2_dataflash_cleanup(c);
747 	}
748 
749 	/* and Intel "Sibley" flash */
750 	if (jffs2_nor_wbuf_flash(c)) {
751 		jffs2_nor_wbuf_flash_cleanup(c);
752 	}
753 
754 	/* and an UBI volume */
755 	if (jffs2_ubivol(c)) {
756 		jffs2_ubivol_cleanup(c);
757 	}
758 }
759