xref: /openbmc/linux/fs/jffs2/fs.c (revision 2169e6da)
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/cred.h>
19 #include <linux/fs.h>
20 #include <linux/list.h>
21 #include <linux/mtd/mtd.h>
22 #include <linux/pagemap.h>
23 #include <linux/slab.h>
24 #include <linux/vmalloc.h>
25 #include <linux/vfs.h>
26 #include <linux/crc32.h>
27 #include "nodelist.h"
28 
29 static int jffs2_flash_setup(struct jffs2_sb_info *c);
30 
31 int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
32 {
33 	struct jffs2_full_dnode *old_metadata, *new_metadata;
34 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
35 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
36 	struct jffs2_raw_inode *ri;
37 	union jffs2_device_node dev;
38 	unsigned char *mdata = NULL;
39 	int mdatalen = 0;
40 	unsigned int ivalid;
41 	uint32_t alloclen;
42 	int ret;
43 	int alloc_type = ALLOC_NORMAL;
44 
45 	jffs2_dbg(1, "%s(): ino #%lu\n", __func__, inode->i_ino);
46 
47 	/* Special cases - we don't want more than one data node
48 	   for these types on the medium at any time. So setattr
49 	   must read the original data associated with the node
50 	   (i.e. the device numbers or the target name) and write
51 	   it out again with the appropriate data attached */
52 	if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
53 		/* For these, we don't actually need to read the old node */
54 		mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
55 		mdata = (char *)&dev;
56 		jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
57 			  __func__, mdatalen);
58 	} else if (S_ISLNK(inode->i_mode)) {
59 		mutex_lock(&f->sem);
60 		mdatalen = f->metadata->size;
61 		mdata = kmalloc(f->metadata->size, GFP_USER);
62 		if (!mdata) {
63 			mutex_unlock(&f->sem);
64 			return -ENOMEM;
65 		}
66 		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
67 		if (ret) {
68 			mutex_unlock(&f->sem);
69 			kfree(mdata);
70 			return ret;
71 		}
72 		mutex_unlock(&f->sem);
73 		jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
74 			  __func__, mdatalen);
75 	}
76 
77 	ri = jffs2_alloc_raw_inode();
78 	if (!ri) {
79 		if (S_ISLNK(inode->i_mode))
80 			kfree(mdata);
81 		return -ENOMEM;
82 	}
83 
84 	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
85 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
86 	if (ret) {
87 		jffs2_free_raw_inode(ri);
88 		if (S_ISLNK(inode->i_mode))
89 			 kfree(mdata);
90 		return ret;
91 	}
92 	mutex_lock(&f->sem);
93 	ivalid = iattr->ia_valid;
94 
95 	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
96 	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
97 	ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
98 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
99 
100 	ri->ino = cpu_to_je32(inode->i_ino);
101 	ri->version = cpu_to_je32(++f->highest_version);
102 
103 	ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
104 		from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
105 	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
106 		from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
107 
108 	if (ivalid & ATTR_MODE)
109 		ri->mode = cpu_to_jemode(iattr->ia_mode);
110 	else
111 		ri->mode = cpu_to_jemode(inode->i_mode);
112 
113 
114 	ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
115 	ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
116 	ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
117 	ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));
118 
119 	ri->offset = cpu_to_je32(0);
120 	ri->csize = ri->dsize = cpu_to_je32(mdatalen);
121 	ri->compr = JFFS2_COMPR_NONE;
122 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
123 		/* It's an extension. Make it a hole node */
124 		ri->compr = JFFS2_COMPR_ZERO;
125 		ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
126 		ri->offset = cpu_to_je32(inode->i_size);
127 	} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
128 		/* For truncate-to-zero, treat it as deletion because
129 		   it'll always be obsoleting all previous nodes */
130 		alloc_type = ALLOC_DELETION;
131 	}
132 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
133 	if (mdatalen)
134 		ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
135 	else
136 		ri->data_crc = cpu_to_je32(0);
137 
138 	new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
139 	if (S_ISLNK(inode->i_mode))
140 		kfree(mdata);
141 
142 	if (IS_ERR(new_metadata)) {
143 		jffs2_complete_reservation(c);
144 		jffs2_free_raw_inode(ri);
145 		mutex_unlock(&f->sem);
146 		return PTR_ERR(new_metadata);
147 	}
148 	/* It worked. Update the inode */
149 	inode->i_atime = ITIME(je32_to_cpu(ri->atime));
150 	inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
151 	inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
152 	inode->i_mode = jemode_to_cpu(ri->mode);
153 	i_uid_write(inode, je16_to_cpu(ri->uid));
154 	i_gid_write(inode, je16_to_cpu(ri->gid));
155 
156 
157 	old_metadata = f->metadata;
158 
159 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
160 		jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
161 
162 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
163 		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
164 		inode->i_size = iattr->ia_size;
165 		inode->i_blocks = (inode->i_size + 511) >> 9;
166 		f->metadata = NULL;
167 	} else {
168 		f->metadata = new_metadata;
169 	}
170 	if (old_metadata) {
171 		jffs2_mark_node_obsolete(c, old_metadata->raw);
172 		jffs2_free_full_dnode(old_metadata);
173 	}
174 	jffs2_free_raw_inode(ri);
175 
176 	mutex_unlock(&f->sem);
177 	jffs2_complete_reservation(c);
178 
179 	/* We have to do the truncate_setsize() without f->sem held, since
180 	   some pages may be locked and waiting for it in readpage().
181 	   We are protected from a simultaneous write() extending i_size
182 	   back past iattr->ia_size, because do_truncate() holds the
183 	   generic inode semaphore. */
184 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
185 		truncate_setsize(inode, iattr->ia_size);
186 		inode->i_blocks = (inode->i_size + 511) >> 9;
187 	}
188 
189 	return 0;
190 }
191 
192 int jffs2_setattr(struct dentry *dentry, struct iattr *iattr)
193 {
194 	struct inode *inode = d_inode(dentry);
195 	int rc;
196 
197 	rc = setattr_prepare(dentry, iattr);
198 	if (rc)
199 		return rc;
200 
201 	rc = jffs2_do_setattr(inode, iattr);
202 	if (!rc && (iattr->ia_valid & ATTR_MODE))
203 		rc = posix_acl_chmod(inode, inode->i_mode);
204 
205 	return rc;
206 }
207 
208 int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
209 {
210 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
211 	unsigned long avail;
212 
213 	buf->f_type = JFFS2_SUPER_MAGIC;
214 	buf->f_bsize = 1 << PAGE_SHIFT;
215 	buf->f_blocks = c->flash_size >> PAGE_SHIFT;
216 	buf->f_files = 0;
217 	buf->f_ffree = 0;
218 	buf->f_namelen = JFFS2_MAX_NAME_LEN;
219 	buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
220 	buf->f_fsid.val[1] = c->mtd->index;
221 
222 	spin_lock(&c->erase_completion_lock);
223 	avail = c->dirty_size + c->free_size;
224 	if (avail > c->sector_size * c->resv_blocks_write)
225 		avail -= c->sector_size * c->resv_blocks_write;
226 	else
227 		avail = 0;
228 	spin_unlock(&c->erase_completion_lock);
229 
230 	buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
231 
232 	return 0;
233 }
234 
235 
236 void jffs2_evict_inode (struct inode *inode)
237 {
238 	/* We can forget about this inode for now - drop all
239 	 *  the nodelists associated with it, etc.
240 	 */
241 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
242 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
243 
244 	jffs2_dbg(1, "%s(): ino #%lu mode %o\n",
245 		  __func__, inode->i_ino, inode->i_mode);
246 	truncate_inode_pages_final(&inode->i_data);
247 	clear_inode(inode);
248 	jffs2_do_clear_inode(c, f);
249 }
250 
251 struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
252 {
253 	struct jffs2_inode_info *f;
254 	struct jffs2_sb_info *c;
255 	struct jffs2_raw_inode latest_node;
256 	union jffs2_device_node jdev;
257 	struct inode *inode;
258 	dev_t rdev = 0;
259 	int ret;
260 
261 	jffs2_dbg(1, "%s(): ino == %lu\n", __func__, ino);
262 
263 	inode = iget_locked(sb, ino);
264 	if (!inode)
265 		return ERR_PTR(-ENOMEM);
266 	if (!(inode->i_state & I_NEW))
267 		return inode;
268 
269 	f = JFFS2_INODE_INFO(inode);
270 	c = JFFS2_SB_INFO(inode->i_sb);
271 
272 	jffs2_init_inode_info(f);
273 	mutex_lock(&f->sem);
274 
275 	ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
276 	if (ret)
277 		goto error;
278 
279 	inode->i_mode = jemode_to_cpu(latest_node.mode);
280 	i_uid_write(inode, je16_to_cpu(latest_node.uid));
281 	i_gid_write(inode, je16_to_cpu(latest_node.gid));
282 	inode->i_size = je32_to_cpu(latest_node.isize);
283 	inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
284 	inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
285 	inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime));
286 
287 	set_nlink(inode, f->inocache->pino_nlink);
288 
289 	inode->i_blocks = (inode->i_size + 511) >> 9;
290 
291 	switch (inode->i_mode & S_IFMT) {
292 
293 	case S_IFLNK:
294 		inode->i_op = &jffs2_symlink_inode_operations;
295 		inode->i_link = f->target;
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 		/* fall through */
344 
345 	case S_IFSOCK:
346 	case S_IFIFO:
347 		inode->i_op = &jffs2_file_inode_operations;
348 		init_special_inode(inode, inode->i_mode, rdev);
349 		break;
350 
351 	default:
352 		pr_warn("%s(): Bogus i_mode %o for ino %lu\n",
353 			__func__, inode->i_mode, (unsigned long)inode->i_ino);
354 	}
355 
356 	mutex_unlock(&f->sem);
357 
358 	jffs2_dbg(1, "jffs2_read_inode() returning\n");
359 	unlock_new_inode(inode);
360 	return inode;
361 
362 error_io:
363 	ret = -EIO;
364 error:
365 	mutex_unlock(&f->sem);
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_rdonly(sb))
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_rdonly(sb)) {
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 & SB_RDONLY))
413 		jffs2_start_garbage_collect_thread(c);
414 
415 	*flags |= SB_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 		mutex_unlock(&f->sem);
460 		make_bad_inode(inode);
461 		iput(inode);
462 		return ERR_PTR(ret);
463 	}
464 	ret = jffs2_do_new_inode (c, f, mode, ri);
465 	if (ret) {
466 		mutex_unlock(&f->sem);
467 		make_bad_inode(inode);
468 		iput(inode);
469 		return ERR_PTR(ret);
470 	}
471 	set_nlink(inode, 1);
472 	inode->i_ino = je32_to_cpu(ri->ino);
473 	inode->i_mode = jemode_to_cpu(ri->mode);
474 	i_gid_write(inode, je16_to_cpu(ri->gid));
475 	i_uid_write(inode, je16_to_cpu(ri->uid));
476 	inode->i_atime = inode->i_ctime = inode->i_mtime = current_time(inode);
477 	ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
478 
479 	inode->i_blocks = 0;
480 	inode->i_size = 0;
481 
482 	if (insert_inode_locked(inode) < 0) {
483 		mutex_unlock(&f->sem);
484 		make_bad_inode(inode);
485 		iput(inode);
486 		return ERR_PTR(-EINVAL);
487 	}
488 
489 	return inode;
490 }
491 
492 static int calculate_inocache_hashsize(uint32_t flash_size)
493 {
494 	/*
495 	 * Pick a inocache hash size based on the size of the medium.
496 	 * Count how many megabytes we're dealing with, apply a hashsize twice
497 	 * that size, but rounding down to the usual big powers of 2. And keep
498 	 * to sensible bounds.
499 	 */
500 
501 	int size_mb = flash_size / 1024 / 1024;
502 	int hashsize = (size_mb * 2) & ~0x3f;
503 
504 	if (hashsize < INOCACHE_HASHSIZE_MIN)
505 		return INOCACHE_HASHSIZE_MIN;
506 	if (hashsize > INOCACHE_HASHSIZE_MAX)
507 		return INOCACHE_HASHSIZE_MAX;
508 
509 	return hashsize;
510 }
511 
512 int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
513 {
514 	struct jffs2_sb_info *c;
515 	struct inode *root_i;
516 	int ret;
517 	size_t blocks;
518 
519 	c = JFFS2_SB_INFO(sb);
520 
521 	/* Do not support the MLC nand */
522 	if (c->mtd->type == MTD_MLCNANDFLASH)
523 		return -EINVAL;
524 
525 #ifndef CONFIG_JFFS2_FS_WRITEBUFFER
526 	if (c->mtd->type == MTD_NANDFLASH) {
527 		pr_err("Cannot operate on NAND flash unless jffs2 NAND support is compiled in\n");
528 		return -EINVAL;
529 	}
530 	if (c->mtd->type == MTD_DATAFLASH) {
531 		pr_err("Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in\n");
532 		return -EINVAL;
533 	}
534 #endif
535 
536 	c->flash_size = c->mtd->size;
537 	c->sector_size = c->mtd->erasesize;
538 	blocks = c->flash_size / c->sector_size;
539 
540 	/*
541 	 * Size alignment check
542 	 */
543 	if ((c->sector_size * blocks) != c->flash_size) {
544 		c->flash_size = c->sector_size * blocks;
545 		pr_info("Flash size not aligned to erasesize, reducing to %dKiB\n",
546 			c->flash_size / 1024);
547 	}
548 
549 	if (c->flash_size < 5*c->sector_size) {
550 		pr_err("Too few erase blocks (%d)\n",
551 		       c->flash_size / c->sector_size);
552 		return -EINVAL;
553 	}
554 
555 	c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
556 
557 	/* NAND (or other bizarre) flash... do setup accordingly */
558 	ret = jffs2_flash_setup(c);
559 	if (ret)
560 		return ret;
561 
562 	c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size);
563 	c->inocache_list = kcalloc(c->inocache_hashsize, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
564 	if (!c->inocache_list) {
565 		ret = -ENOMEM;
566 		goto out_wbuf;
567 	}
568 
569 	jffs2_init_xattr_subsystem(c);
570 
571 	if ((ret = jffs2_do_mount_fs(c)))
572 		goto out_inohash;
573 
574 	jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
575 	root_i = jffs2_iget(sb, 1);
576 	if (IS_ERR(root_i)) {
577 		jffs2_dbg(1, "get root inode failed\n");
578 		ret = PTR_ERR(root_i);
579 		goto out_root;
580 	}
581 
582 	ret = -ENOMEM;
583 
584 	jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
585 	sb->s_root = d_make_root(root_i);
586 	if (!sb->s_root)
587 		goto out_root;
588 
589 	sb->s_maxbytes = 0xFFFFFFFF;
590 	sb->s_blocksize = PAGE_SIZE;
591 	sb->s_blocksize_bits = PAGE_SHIFT;
592 	sb->s_magic = JFFS2_SUPER_MAGIC;
593 	if (!sb_rdonly(sb))
594 		jffs2_start_garbage_collect_thread(c);
595 	return 0;
596 
597 out_root:
598 	jffs2_free_ino_caches(c);
599 	jffs2_free_raw_node_refs(c);
600 	kvfree(c->blocks);
601  out_inohash:
602 	jffs2_clear_xattr_subsystem(c);
603 	kfree(c->inocache_list);
604  out_wbuf:
605 	jffs2_flash_cleanup(c);
606 
607 	return ret;
608 }
609 
610 void jffs2_gc_release_inode(struct jffs2_sb_info *c,
611 				   struct jffs2_inode_info *f)
612 {
613 	iput(OFNI_EDONI_2SFFJ(f));
614 }
615 
616 struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
617 					      int inum, int unlinked)
618 {
619 	struct inode *inode;
620 	struct jffs2_inode_cache *ic;
621 
622 	if (unlinked) {
623 		/* The inode has zero nlink but its nodes weren't yet marked
624 		   obsolete. This has to be because we're still waiting for
625 		   the final (close() and) iput() to happen.
626 
627 		   There's a possibility that the final iput() could have
628 		   happened while we were contemplating. In order to ensure
629 		   that we don't cause a new read_inode() (which would fail)
630 		   for the inode in question, we use ilookup() in this case
631 		   instead of iget().
632 
633 		   The nlink can't _become_ zero at this point because we're
634 		   holding the alloc_sem, and jffs2_do_unlink() would also
635 		   need that while decrementing nlink on any inode.
636 		*/
637 		inode = ilookup(OFNI_BS_2SFFJ(c), inum);
638 		if (!inode) {
639 			jffs2_dbg(1, "ilookup() failed for ino #%u; inode is probably deleted.\n",
640 				  inum);
641 
642 			spin_lock(&c->inocache_lock);
643 			ic = jffs2_get_ino_cache(c, inum);
644 			if (!ic) {
645 				jffs2_dbg(1, "Inode cache for ino #%u is gone\n",
646 					  inum);
647 				spin_unlock(&c->inocache_lock);
648 				return NULL;
649 			}
650 			if (ic->state != INO_STATE_CHECKEDABSENT) {
651 				/* Wait for progress. Don't just loop */
652 				jffs2_dbg(1, "Waiting for ino #%u in state %d\n",
653 					  ic->ino, ic->state);
654 				sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
655 			} else {
656 				spin_unlock(&c->inocache_lock);
657 			}
658 
659 			return NULL;
660 		}
661 	} else {
662 		/* Inode has links to it still; they're not going away because
663 		   jffs2_do_unlink() would need the alloc_sem and we have it.
664 		   Just iget() it, and if read_inode() is necessary that's OK.
665 		*/
666 		inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
667 		if (IS_ERR(inode))
668 			return ERR_CAST(inode);
669 	}
670 	if (is_bad_inode(inode)) {
671 		pr_notice("Eep. read_inode() failed for ino #%u. unlinked %d\n",
672 			  inum, unlinked);
673 		/* NB. This will happen again. We need to do something appropriate here. */
674 		iput(inode);
675 		return ERR_PTR(-EIO);
676 	}
677 
678 	return JFFS2_INODE_INFO(inode);
679 }
680 
681 unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c,
682 				   struct jffs2_inode_info *f,
683 				   unsigned long offset,
684 				   unsigned long *priv)
685 {
686 	struct inode *inode = OFNI_EDONI_2SFFJ(f);
687 	struct page *pg;
688 
689 	pg = read_cache_page(inode->i_mapping, offset >> PAGE_SHIFT,
690 			     jffs2_do_readpage_unlock, inode);
691 	if (IS_ERR(pg))
692 		return (void *)pg;
693 
694 	*priv = (unsigned long)pg;
695 	return kmap(pg);
696 }
697 
698 void jffs2_gc_release_page(struct jffs2_sb_info *c,
699 			   unsigned char *ptr,
700 			   unsigned long *priv)
701 {
702 	struct page *pg = (void *)*priv;
703 
704 	kunmap(pg);
705 	put_page(pg);
706 }
707 
708 static int jffs2_flash_setup(struct jffs2_sb_info *c) {
709 	int ret = 0;
710 
711 	if (jffs2_cleanmarker_oob(c)) {
712 		/* NAND flash... do setup accordingly */
713 		ret = jffs2_nand_flash_setup(c);
714 		if (ret)
715 			return ret;
716 	}
717 
718 	/* and Dataflash */
719 	if (jffs2_dataflash(c)) {
720 		ret = jffs2_dataflash_setup(c);
721 		if (ret)
722 			return ret;
723 	}
724 
725 	/* and Intel "Sibley" flash */
726 	if (jffs2_nor_wbuf_flash(c)) {
727 		ret = jffs2_nor_wbuf_flash_setup(c);
728 		if (ret)
729 			return ret;
730 	}
731 
732 	/* and an UBI volume */
733 	if (jffs2_ubivol(c)) {
734 		ret = jffs2_ubivol_setup(c);
735 		if (ret)
736 			return ret;
737 	}
738 
739 	return ret;
740 }
741 
742 void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
743 
744 	if (jffs2_cleanmarker_oob(c)) {
745 		jffs2_nand_flash_cleanup(c);
746 	}
747 
748 	/* and DataFlash */
749 	if (jffs2_dataflash(c)) {
750 		jffs2_dataflash_cleanup(c);
751 	}
752 
753 	/* and Intel "Sibley" flash */
754 	if (jffs2_nor_wbuf_flash(c)) {
755 		jffs2_nor_wbuf_flash_cleanup(c);
756 	}
757 
758 	/* and an UBI volume */
759 	if (jffs2_ubivol(c)) {
760 		jffs2_ubivol_cleanup(c);
761 	}
762 }
763