xref: /openbmc/linux/fs/jffs2/fs.c (revision a09d2831)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11 
12 #include <linux/capability.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/fs.h>
16 #include <linux/list.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/pagemap.h>
19 #include <linux/slab.h>
20 #include <linux/vmalloc.h>
21 #include <linux/vfs.h>
22 #include <linux/crc32.h>
23 #include <linux/smp_lock.h>
24 #include "nodelist.h"
25 
26 static int jffs2_flash_setup(struct jffs2_sb_info *c);
27 
28 int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
29 {
30 	struct jffs2_full_dnode *old_metadata, *new_metadata;
31 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
32 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
33 	struct jffs2_raw_inode *ri;
34 	union jffs2_device_node dev;
35 	unsigned char *mdata = NULL;
36 	int mdatalen = 0;
37 	unsigned int ivalid;
38 	uint32_t alloclen;
39 	int ret;
40 	int alloc_type = ALLOC_NORMAL;
41 
42 	D1(printk(KERN_DEBUG "jffs2_setattr(): ino #%lu\n", inode->i_ino));
43 
44 	/* Special cases - we don't want more than one data node
45 	   for these types on the medium at any time. So setattr
46 	   must read the original data associated with the node
47 	   (i.e. the device numbers or the target name) and write
48 	   it out again with the appropriate data attached */
49 	if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
50 		/* For these, we don't actually need to read the old node */
51 		mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
52 		mdata = (char *)&dev;
53 		D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of kdev_t\n", mdatalen));
54 	} else if (S_ISLNK(inode->i_mode)) {
55 		mutex_lock(&f->sem);
56 		mdatalen = f->metadata->size;
57 		mdata = kmalloc(f->metadata->size, GFP_USER);
58 		if (!mdata) {
59 			mutex_unlock(&f->sem);
60 			return -ENOMEM;
61 		}
62 		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
63 		if (ret) {
64 			mutex_unlock(&f->sem);
65 			kfree(mdata);
66 			return ret;
67 		}
68 		mutex_unlock(&f->sem);
69 		D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of symlink target\n", mdatalen));
70 	}
71 
72 	ri = jffs2_alloc_raw_inode();
73 	if (!ri) {
74 		if (S_ISLNK(inode->i_mode))
75 			kfree(mdata);
76 		return -ENOMEM;
77 	}
78 
79 	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
80 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
81 	if (ret) {
82 		jffs2_free_raw_inode(ri);
83 		if (S_ISLNK(inode->i_mode & S_IFMT))
84 			 kfree(mdata);
85 		return ret;
86 	}
87 	mutex_lock(&f->sem);
88 	ivalid = iattr->ia_valid;
89 
90 	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
91 	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
92 	ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
93 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
94 
95 	ri->ino = cpu_to_je32(inode->i_ino);
96 	ri->version = cpu_to_je32(++f->highest_version);
97 
98 	ri->uid = cpu_to_je16((ivalid & ATTR_UID)?iattr->ia_uid:inode->i_uid);
99 	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?iattr->ia_gid:inode->i_gid);
100 
101 	if (ivalid & ATTR_MODE)
102 		ri->mode = cpu_to_jemode(iattr->ia_mode);
103 	else
104 		ri->mode = cpu_to_jemode(inode->i_mode);
105 
106 
107 	ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
108 	ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
109 	ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
110 	ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));
111 
112 	ri->offset = cpu_to_je32(0);
113 	ri->csize = ri->dsize = cpu_to_je32(mdatalen);
114 	ri->compr = JFFS2_COMPR_NONE;
115 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
116 		/* It's an extension. Make it a hole node */
117 		ri->compr = JFFS2_COMPR_ZERO;
118 		ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
119 		ri->offset = cpu_to_je32(inode->i_size);
120 	} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
121 		/* For truncate-to-zero, treat it as deletion because
122 		   it'll always be obsoleting all previous nodes */
123 		alloc_type = ALLOC_DELETION;
124 	}
125 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
126 	if (mdatalen)
127 		ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
128 	else
129 		ri->data_crc = cpu_to_je32(0);
130 
131 	new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
132 	if (S_ISLNK(inode->i_mode))
133 		kfree(mdata);
134 
135 	if (IS_ERR(new_metadata)) {
136 		jffs2_complete_reservation(c);
137 		jffs2_free_raw_inode(ri);
138 		mutex_unlock(&f->sem);
139 		return PTR_ERR(new_metadata);
140 	}
141 	/* It worked. Update the inode */
142 	inode->i_atime = ITIME(je32_to_cpu(ri->atime));
143 	inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
144 	inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
145 	inode->i_mode = jemode_to_cpu(ri->mode);
146 	inode->i_uid = je16_to_cpu(ri->uid);
147 	inode->i_gid = je16_to_cpu(ri->gid);
148 
149 
150 	old_metadata = f->metadata;
151 
152 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
153 		jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
154 
155 	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
156 		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
157 		inode->i_size = iattr->ia_size;
158 		inode->i_blocks = (inode->i_size + 511) >> 9;
159 		f->metadata = NULL;
160 	} else {
161 		f->metadata = new_metadata;
162 	}
163 	if (old_metadata) {
164 		jffs2_mark_node_obsolete(c, old_metadata->raw);
165 		jffs2_free_full_dnode(old_metadata);
166 	}
167 	jffs2_free_raw_inode(ri);
168 
169 	mutex_unlock(&f->sem);
170 	jffs2_complete_reservation(c);
171 
172 	/* We have to do the vmtruncate() without f->sem held, since
173 	   some pages may be locked and waiting for it in readpage().
174 	   We are protected from a simultaneous write() extending i_size
175 	   back past iattr->ia_size, because do_truncate() holds the
176 	   generic inode semaphore. */
177 	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
178 		vmtruncate(inode, iattr->ia_size);
179 		inode->i_blocks = (inode->i_size + 511) >> 9;
180 	}
181 
182 	return 0;
183 }
184 
185 int jffs2_setattr(struct dentry *dentry, struct iattr *iattr)
186 {
187 	int rc;
188 
189 	rc = inode_change_ok(dentry->d_inode, iattr);
190 	if (rc)
191 		return rc;
192 
193 	rc = jffs2_do_setattr(dentry->d_inode, iattr);
194 	if (!rc && (iattr->ia_valid & ATTR_MODE))
195 		rc = jffs2_acl_chmod(dentry->d_inode);
196 
197 	return rc;
198 }
199 
200 int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
201 {
202 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
203 	unsigned long avail;
204 
205 	buf->f_type = JFFS2_SUPER_MAGIC;
206 	buf->f_bsize = 1 << PAGE_SHIFT;
207 	buf->f_blocks = c->flash_size >> PAGE_SHIFT;
208 	buf->f_files = 0;
209 	buf->f_ffree = 0;
210 	buf->f_namelen = JFFS2_MAX_NAME_LEN;
211 	buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
212 	buf->f_fsid.val[1] = c->mtd->index;
213 
214 	spin_lock(&c->erase_completion_lock);
215 	avail = c->dirty_size + c->free_size;
216 	if (avail > c->sector_size * c->resv_blocks_write)
217 		avail -= c->sector_size * c->resv_blocks_write;
218 	else
219 		avail = 0;
220 	spin_unlock(&c->erase_completion_lock);
221 
222 	buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
223 
224 	return 0;
225 }
226 
227 
228 void jffs2_clear_inode (struct inode *inode)
229 {
230 	/* We can forget about this inode for now - drop all
231 	 *  the nodelists associated with it, etc.
232 	 */
233 	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
234 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
235 
236 	D1(printk(KERN_DEBUG "jffs2_clear_inode(): ino #%lu mode %o\n", inode->i_ino, inode->i_mode));
237 	jffs2_do_clear_inode(c, f);
238 }
239 
240 struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
241 {
242 	struct jffs2_inode_info *f;
243 	struct jffs2_sb_info *c;
244 	struct jffs2_raw_inode latest_node;
245 	union jffs2_device_node jdev;
246 	struct inode *inode;
247 	dev_t rdev = 0;
248 	int ret;
249 
250 	D1(printk(KERN_DEBUG "jffs2_iget(): ino == %lu\n", ino));
251 
252 	inode = iget_locked(sb, ino);
253 	if (!inode)
254 		return ERR_PTR(-ENOMEM);
255 	if (!(inode->i_state & I_NEW))
256 		return inode;
257 
258 	f = JFFS2_INODE_INFO(inode);
259 	c = JFFS2_SB_INFO(inode->i_sb);
260 
261 	jffs2_init_inode_info(f);
262 	mutex_lock(&f->sem);
263 
264 	ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
265 
266 	if (ret) {
267 		mutex_unlock(&f->sem);
268 		iget_failed(inode);
269 		return ERR_PTR(ret);
270 	}
271 	inode->i_mode = jemode_to_cpu(latest_node.mode);
272 	inode->i_uid = je16_to_cpu(latest_node.uid);
273 	inode->i_gid = je16_to_cpu(latest_node.gid);
274 	inode->i_size = je32_to_cpu(latest_node.isize);
275 	inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
276 	inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
277 	inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime));
278 
279 	inode->i_nlink = f->inocache->pino_nlink;
280 
281 	inode->i_blocks = (inode->i_size + 511) >> 9;
282 
283 	switch (inode->i_mode & S_IFMT) {
284 
285 	case S_IFLNK:
286 		inode->i_op = &jffs2_symlink_inode_operations;
287 		break;
288 
289 	case S_IFDIR:
290 	{
291 		struct jffs2_full_dirent *fd;
292 		inode->i_nlink = 2; /* parent and '.' */
293 
294 		for (fd=f->dents; fd; fd = fd->next) {
295 			if (fd->type == DT_DIR && fd->ino)
296 				inc_nlink(inode);
297 		}
298 		/* Root dir gets i_nlink 3 for some reason */
299 		if (inode->i_ino == 1)
300 			inc_nlink(inode);
301 
302 		inode->i_op = &jffs2_dir_inode_operations;
303 		inode->i_fop = &jffs2_dir_operations;
304 		break;
305 	}
306 	case S_IFREG:
307 		inode->i_op = &jffs2_file_inode_operations;
308 		inode->i_fop = &jffs2_file_operations;
309 		inode->i_mapping->a_ops = &jffs2_file_address_operations;
310 		inode->i_mapping->nrpages = 0;
311 		break;
312 
313 	case S_IFBLK:
314 	case S_IFCHR:
315 		/* Read the device numbers from the media */
316 		if (f->metadata->size != sizeof(jdev.old) &&
317 		    f->metadata->size != sizeof(jdev.new)) {
318 			printk(KERN_NOTICE "Device node has strange size %d\n", f->metadata->size);
319 			goto error_io;
320 		}
321 		D1(printk(KERN_DEBUG "Reading device numbers from flash\n"));
322 		ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
323 		if (ret < 0) {
324 			/* Eep */
325 			printk(KERN_NOTICE "Read device numbers for inode %lu failed\n", (unsigned long)inode->i_ino);
326 			goto error;
327 		}
328 		if (f->metadata->size == sizeof(jdev.old))
329 			rdev = old_decode_dev(je16_to_cpu(jdev.old));
330 		else
331 			rdev = new_decode_dev(je32_to_cpu(jdev.new));
332 
333 	case S_IFSOCK:
334 	case S_IFIFO:
335 		inode->i_op = &jffs2_file_inode_operations;
336 		init_special_inode(inode, inode->i_mode, rdev);
337 		break;
338 
339 	default:
340 		printk(KERN_WARNING "jffs2_read_inode(): Bogus imode %o for ino %lu\n", inode->i_mode, (unsigned long)inode->i_ino);
341 	}
342 
343 	mutex_unlock(&f->sem);
344 
345 	D1(printk(KERN_DEBUG "jffs2_read_inode() returning\n"));
346 	unlock_new_inode(inode);
347 	return inode;
348 
349 error_io:
350 	ret = -EIO;
351 error:
352 	mutex_unlock(&f->sem);
353 	jffs2_do_clear_inode(c, f);
354 	iget_failed(inode);
355 	return ERR_PTR(ret);
356 }
357 
358 void jffs2_dirty_inode(struct inode *inode)
359 {
360 	struct iattr iattr;
361 
362 	if (!(inode->i_state & I_DIRTY_DATASYNC)) {
363 		D2(printk(KERN_DEBUG "jffs2_dirty_inode() not calling setattr() for ino #%lu\n", inode->i_ino));
364 		return;
365 	}
366 
367 	D1(printk(KERN_DEBUG "jffs2_dirty_inode() calling setattr() for ino #%lu\n", inode->i_ino));
368 
369 	iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
370 	iattr.ia_mode = inode->i_mode;
371 	iattr.ia_uid = inode->i_uid;
372 	iattr.ia_gid = inode->i_gid;
373 	iattr.ia_atime = inode->i_atime;
374 	iattr.ia_mtime = inode->i_mtime;
375 	iattr.ia_ctime = inode->i_ctime;
376 
377 	jffs2_do_setattr(inode, &iattr);
378 }
379 
380 int jffs2_remount_fs (struct super_block *sb, int *flags, char *data)
381 {
382 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
383 
384 	if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
385 		return -EROFS;
386 
387 	/* We stop if it was running, then restart if it needs to.
388 	   This also catches the case where it was stopped and this
389 	   is just a remount to restart it.
390 	   Flush the writebuffer, if neccecary, else we loose it */
391 	lock_kernel();
392 	if (!(sb->s_flags & MS_RDONLY)) {
393 		jffs2_stop_garbage_collect_thread(c);
394 		mutex_lock(&c->alloc_sem);
395 		jffs2_flush_wbuf_pad(c);
396 		mutex_unlock(&c->alloc_sem);
397 	}
398 
399 	if (!(*flags & MS_RDONLY))
400 		jffs2_start_garbage_collect_thread(c);
401 
402 	*flags |= MS_NOATIME;
403 
404 	unlock_kernel();
405 	return 0;
406 }
407 
408 /* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
409    fill in the raw_inode while you're at it. */
410 struct inode *jffs2_new_inode (struct inode *dir_i, int mode, struct jffs2_raw_inode *ri)
411 {
412 	struct inode *inode;
413 	struct super_block *sb = dir_i->i_sb;
414 	struct jffs2_sb_info *c;
415 	struct jffs2_inode_info *f;
416 	int ret;
417 
418 	D1(printk(KERN_DEBUG "jffs2_new_inode(): dir_i %ld, mode 0x%x\n", dir_i->i_ino, mode));
419 
420 	c = JFFS2_SB_INFO(sb);
421 
422 	inode = new_inode(sb);
423 
424 	if (!inode)
425 		return ERR_PTR(-ENOMEM);
426 
427 	f = JFFS2_INODE_INFO(inode);
428 	jffs2_init_inode_info(f);
429 	mutex_lock(&f->sem);
430 
431 	memset(ri, 0, sizeof(*ri));
432 	/* Set OS-specific defaults for new inodes */
433 	ri->uid = cpu_to_je16(current_fsuid());
434 
435 	if (dir_i->i_mode & S_ISGID) {
436 		ri->gid = cpu_to_je16(dir_i->i_gid);
437 		if (S_ISDIR(mode))
438 			mode |= S_ISGID;
439 	} else {
440 		ri->gid = cpu_to_je16(current_fsgid());
441 	}
442 
443 	/* POSIX ACLs have to be processed now, at least partly.
444 	   The umask is only applied if there's no default ACL */
445 	ret = jffs2_init_acl_pre(dir_i, inode, &mode);
446 	if (ret) {
447 	    make_bad_inode(inode);
448 	    iput(inode);
449 	    return ERR_PTR(ret);
450 	}
451 	ret = jffs2_do_new_inode (c, f, mode, ri);
452 	if (ret) {
453 		make_bad_inode(inode);
454 		iput(inode);
455 		return ERR_PTR(ret);
456 	}
457 	inode->i_nlink = 1;
458 	inode->i_ino = je32_to_cpu(ri->ino);
459 	inode->i_mode = jemode_to_cpu(ri->mode);
460 	inode->i_gid = je16_to_cpu(ri->gid);
461 	inode->i_uid = je16_to_cpu(ri->uid);
462 	inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
463 	ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
464 
465 	inode->i_blocks = 0;
466 	inode->i_size = 0;
467 
468 	insert_inode_hash(inode);
469 
470 	return inode;
471 }
472 
473 
474 int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
475 {
476 	struct jffs2_sb_info *c;
477 	struct inode *root_i;
478 	int ret;
479 	size_t blocks;
480 
481 	c = JFFS2_SB_INFO(sb);
482 
483 #ifndef CONFIG_JFFS2_FS_WRITEBUFFER
484 	if (c->mtd->type == MTD_NANDFLASH) {
485 		printk(KERN_ERR "jffs2: Cannot operate on NAND flash unless jffs2 NAND support is compiled in.\n");
486 		return -EINVAL;
487 	}
488 	if (c->mtd->type == MTD_DATAFLASH) {
489 		printk(KERN_ERR "jffs2: Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in.\n");
490 		return -EINVAL;
491 	}
492 #endif
493 
494 	c->flash_size = c->mtd->size;
495 	c->sector_size = c->mtd->erasesize;
496 	blocks = c->flash_size / c->sector_size;
497 
498 	/*
499 	 * Size alignment check
500 	 */
501 	if ((c->sector_size * blocks) != c->flash_size) {
502 		c->flash_size = c->sector_size * blocks;
503 		printk(KERN_INFO "jffs2: Flash size not aligned to erasesize, reducing to %dKiB\n",
504 			c->flash_size / 1024);
505 	}
506 
507 	if (c->flash_size < 5*c->sector_size) {
508 		printk(KERN_ERR "jffs2: Too few erase blocks (%d)\n", c->flash_size / c->sector_size);
509 		return -EINVAL;
510 	}
511 
512 	c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
513 
514 	/* NAND (or other bizarre) flash... do setup accordingly */
515 	ret = jffs2_flash_setup(c);
516 	if (ret)
517 		return ret;
518 
519 	c->inocache_list = kcalloc(INOCACHE_HASHSIZE, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
520 	if (!c->inocache_list) {
521 		ret = -ENOMEM;
522 		goto out_wbuf;
523 	}
524 
525 	jffs2_init_xattr_subsystem(c);
526 
527 	if ((ret = jffs2_do_mount_fs(c)))
528 		goto out_inohash;
529 
530 	D1(printk(KERN_DEBUG "jffs2_do_fill_super(): Getting root inode\n"));
531 	root_i = jffs2_iget(sb, 1);
532 	if (IS_ERR(root_i)) {
533 		D1(printk(KERN_WARNING "get root inode failed\n"));
534 		ret = PTR_ERR(root_i);
535 		goto out_root;
536 	}
537 
538 	ret = -ENOMEM;
539 
540 	D1(printk(KERN_DEBUG "jffs2_do_fill_super(): d_alloc_root()\n"));
541 	sb->s_root = d_alloc_root(root_i);
542 	if (!sb->s_root)
543 		goto out_root_i;
544 
545 	sb->s_maxbytes = 0xFFFFFFFF;
546 	sb->s_blocksize = PAGE_CACHE_SIZE;
547 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
548 	sb->s_magic = JFFS2_SUPER_MAGIC;
549 	if (!(sb->s_flags & MS_RDONLY))
550 		jffs2_start_garbage_collect_thread(c);
551 	return 0;
552 
553  out_root_i:
554 	iput(root_i);
555 out_root:
556 	jffs2_free_ino_caches(c);
557 	jffs2_free_raw_node_refs(c);
558 	if (jffs2_blocks_use_vmalloc(c))
559 		vfree(c->blocks);
560 	else
561 		kfree(c->blocks);
562  out_inohash:
563 	jffs2_clear_xattr_subsystem(c);
564 	kfree(c->inocache_list);
565  out_wbuf:
566 	jffs2_flash_cleanup(c);
567 
568 	return ret;
569 }
570 
571 void jffs2_gc_release_inode(struct jffs2_sb_info *c,
572 				   struct jffs2_inode_info *f)
573 {
574 	iput(OFNI_EDONI_2SFFJ(f));
575 }
576 
577 struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
578 					      int inum, int unlinked)
579 {
580 	struct inode *inode;
581 	struct jffs2_inode_cache *ic;
582 
583 	if (unlinked) {
584 		/* The inode has zero nlink but its nodes weren't yet marked
585 		   obsolete. This has to be because we're still waiting for
586 		   the final (close() and) iput() to happen.
587 
588 		   There's a possibility that the final iput() could have
589 		   happened while we were contemplating. In order to ensure
590 		   that we don't cause a new read_inode() (which would fail)
591 		   for the inode in question, we use ilookup() in this case
592 		   instead of iget().
593 
594 		   The nlink can't _become_ zero at this point because we're
595 		   holding the alloc_sem, and jffs2_do_unlink() would also
596 		   need that while decrementing nlink on any inode.
597 		*/
598 		inode = ilookup(OFNI_BS_2SFFJ(c), inum);
599 		if (!inode) {
600 			D1(printk(KERN_DEBUG "ilookup() failed for ino #%u; inode is probably deleted.\n",
601 				  inum));
602 
603 			spin_lock(&c->inocache_lock);
604 			ic = jffs2_get_ino_cache(c, inum);
605 			if (!ic) {
606 				D1(printk(KERN_DEBUG "Inode cache for ino #%u is gone.\n", inum));
607 				spin_unlock(&c->inocache_lock);
608 				return NULL;
609 			}
610 			if (ic->state != INO_STATE_CHECKEDABSENT) {
611 				/* Wait for progress. Don't just loop */
612 				D1(printk(KERN_DEBUG "Waiting for ino #%u in state %d\n",
613 					  ic->ino, ic->state));
614 				sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
615 			} else {
616 				spin_unlock(&c->inocache_lock);
617 			}
618 
619 			return NULL;
620 		}
621 	} else {
622 		/* Inode has links to it still; they're not going away because
623 		   jffs2_do_unlink() would need the alloc_sem and we have it.
624 		   Just iget() it, and if read_inode() is necessary that's OK.
625 		*/
626 		inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
627 		if (IS_ERR(inode))
628 			return ERR_CAST(inode);
629 	}
630 	if (is_bad_inode(inode)) {
631 		printk(KERN_NOTICE "Eep. read_inode() failed for ino #%u. unlinked %d\n",
632 		       inum, unlinked);
633 		/* NB. This will happen again. We need to do something appropriate here. */
634 		iput(inode);
635 		return ERR_PTR(-EIO);
636 	}
637 
638 	return JFFS2_INODE_INFO(inode);
639 }
640 
641 unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c,
642 				   struct jffs2_inode_info *f,
643 				   unsigned long offset,
644 				   unsigned long *priv)
645 {
646 	struct inode *inode = OFNI_EDONI_2SFFJ(f);
647 	struct page *pg;
648 
649 	pg = read_cache_page_async(inode->i_mapping, offset >> PAGE_CACHE_SHIFT,
650 			     (void *)jffs2_do_readpage_unlock, inode);
651 	if (IS_ERR(pg))
652 		return (void *)pg;
653 
654 	*priv = (unsigned long)pg;
655 	return kmap(pg);
656 }
657 
658 void jffs2_gc_release_page(struct jffs2_sb_info *c,
659 			   unsigned char *ptr,
660 			   unsigned long *priv)
661 {
662 	struct page *pg = (void *)*priv;
663 
664 	kunmap(pg);
665 	page_cache_release(pg);
666 }
667 
668 static int jffs2_flash_setup(struct jffs2_sb_info *c) {
669 	int ret = 0;
670 
671 	if (jffs2_cleanmarker_oob(c)) {
672 		/* NAND flash... do setup accordingly */
673 		ret = jffs2_nand_flash_setup(c);
674 		if (ret)
675 			return ret;
676 	}
677 
678 	/* and Dataflash */
679 	if (jffs2_dataflash(c)) {
680 		ret = jffs2_dataflash_setup(c);
681 		if (ret)
682 			return ret;
683 	}
684 
685 	/* and Intel "Sibley" flash */
686 	if (jffs2_nor_wbuf_flash(c)) {
687 		ret = jffs2_nor_wbuf_flash_setup(c);
688 		if (ret)
689 			return ret;
690 	}
691 
692 	/* and an UBI volume */
693 	if (jffs2_ubivol(c)) {
694 		ret = jffs2_ubivol_setup(c);
695 		if (ret)
696 			return ret;
697 	}
698 
699 	return ret;
700 }
701 
702 void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
703 
704 	if (jffs2_cleanmarker_oob(c)) {
705 		jffs2_nand_flash_cleanup(c);
706 	}
707 
708 	/* and DataFlash */
709 	if (jffs2_dataflash(c)) {
710 		jffs2_dataflash_cleanup(c);
711 	}
712 
713 	/* and Intel "Sibley" flash */
714 	if (jffs2_nor_wbuf_flash(c)) {
715 		jffs2_nor_wbuf_flash_cleanup(c);
716 	}
717 
718 	/* and an UBI volume */
719 	if (jffs2_ubivol(c)) {
720 		jffs2_ubivol_cleanup(c);
721 	}
722 }
723