xref: /openbmc/linux/fs/jffs2/write.c (revision 5bd5c03c)
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/kernel.h>
13 #include <linux/fs.h>
14 #include <linux/crc32.h>
15 #include <linux/slab.h>
16 #include <linux/pagemap.h>
17 #include <linux/mtd/mtd.h>
18 #include "nodelist.h"
19 #include "compr.h"
20 
21 
22 int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint32_t mode, struct jffs2_raw_inode *ri)
23 {
24 	struct jffs2_inode_cache *ic;
25 
26 	ic = jffs2_alloc_inode_cache();
27 	if (!ic) {
28 		return -ENOMEM;
29 	}
30 
31 	memset(ic, 0, sizeof(*ic));
32 
33 	f->inocache = ic;
34 	f->inocache->nlink = 1;
35 	f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
36 	f->inocache->state = INO_STATE_PRESENT;
37 
38 	jffs2_add_ino_cache(c, f->inocache);
39 	D1(printk(KERN_DEBUG "jffs2_do_new_inode(): Assigned ino# %d\n", f->inocache->ino));
40 	ri->ino = cpu_to_je32(f->inocache->ino);
41 
42 	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
43 	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
44 	ri->totlen = cpu_to_je32(PAD(sizeof(*ri)));
45 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
46 	ri->mode = cpu_to_jemode(mode);
47 
48 	f->highest_version = 1;
49 	ri->version = cpu_to_je32(f->highest_version);
50 
51 	return 0;
52 }
53 
54 /* jffs2_write_dnode - given a raw_inode, allocate a full_dnode for it,
55    write it to the flash, link it into the existing inode/fragment list */
56 
57 struct jffs2_full_dnode *jffs2_write_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
58 					   struct jffs2_raw_inode *ri, const unsigned char *data,
59 					   uint32_t datalen, int alloc_mode)
60 
61 {
62 	struct jffs2_full_dnode *fn;
63 	size_t retlen;
64 	uint32_t flash_ofs;
65 	struct kvec vecs[2];
66 	int ret;
67 	int retried = 0;
68 	unsigned long cnt = 2;
69 
70 	D1(if(je32_to_cpu(ri->hdr_crc) != crc32(0, ri, sizeof(struct jffs2_unknown_node)-4)) {
71 		printk(KERN_CRIT "Eep. CRC not correct in jffs2_write_dnode()\n");
72 		BUG();
73 	}
74 	   );
75 	vecs[0].iov_base = ri;
76 	vecs[0].iov_len = sizeof(*ri);
77 	vecs[1].iov_base = (unsigned char *)data;
78 	vecs[1].iov_len = datalen;
79 
80 	if (je32_to_cpu(ri->totlen) != sizeof(*ri) + datalen) {
81 		printk(KERN_WARNING "jffs2_write_dnode: ri->totlen (0x%08x) != sizeof(*ri) (0x%08zx) + datalen (0x%08x)\n", je32_to_cpu(ri->totlen), sizeof(*ri), datalen);
82 	}
83 
84 	fn = jffs2_alloc_full_dnode();
85 	if (!fn)
86 		return ERR_PTR(-ENOMEM);
87 
88 	/* check number of valid vecs */
89 	if (!datalen || !data)
90 		cnt = 1;
91  retry:
92 	flash_ofs = write_ofs(c);
93 
94 	jffs2_dbg_prewrite_paranoia_check(c, flash_ofs, vecs[0].iov_len + vecs[1].iov_len);
95 
96 	if ((alloc_mode!=ALLOC_GC) && (je32_to_cpu(ri->version) < f->highest_version)) {
97 		BUG_ON(!retried);
98 		D1(printk(KERN_DEBUG "jffs2_write_dnode : dnode_version %d, "
99 				"highest version %d -> updating dnode\n",
100 				je32_to_cpu(ri->version), f->highest_version));
101 		ri->version = cpu_to_je32(++f->highest_version);
102 		ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
103 	}
104 
105 	ret = jffs2_flash_writev(c, vecs, cnt, flash_ofs, &retlen,
106 				 (alloc_mode==ALLOC_GC)?0:f->inocache->ino);
107 
108 	if (ret || (retlen != sizeof(*ri) + datalen)) {
109 		printk(KERN_NOTICE "Write of %zd bytes at 0x%08x failed. returned %d, retlen %zd\n",
110 		       sizeof(*ri)+datalen, flash_ofs, ret, retlen);
111 
112 		/* Mark the space as dirtied */
113 		if (retlen) {
114 			/* Don't change raw->size to match retlen. We may have
115 			   written the node header already, and only the data will
116 			   seem corrupted, in which case the scan would skip over
117 			   any node we write before the original intended end of
118 			   this node */
119 			jffs2_add_physical_node_ref(c, flash_ofs | REF_OBSOLETE, PAD(sizeof(*ri)+datalen), NULL);
120 		} else {
121 			printk(KERN_NOTICE "Not marking the space at 0x%08x as dirty because the flash driver returned retlen zero\n", flash_ofs);
122 		}
123 		if (!retried && alloc_mode != ALLOC_NORETRY) {
124 			/* Try to reallocate space and retry */
125 			uint32_t dummy;
126 			struct jffs2_eraseblock *jeb = &c->blocks[flash_ofs / c->sector_size];
127 
128 			retried = 1;
129 
130 			D1(printk(KERN_DEBUG "Retrying failed write.\n"));
131 
132 			jffs2_dbg_acct_sanity_check(c,jeb);
133 			jffs2_dbg_acct_paranoia_check(c, jeb);
134 
135 			if (alloc_mode == ALLOC_GC) {
136 				ret = jffs2_reserve_space_gc(c, sizeof(*ri) + datalen, &dummy,
137 							     JFFS2_SUMMARY_INODE_SIZE);
138 			} else {
139 				/* Locking pain */
140 				up(&f->sem);
141 				jffs2_complete_reservation(c);
142 
143 				ret = jffs2_reserve_space(c, sizeof(*ri) + datalen, &dummy,
144 							  alloc_mode, JFFS2_SUMMARY_INODE_SIZE);
145 				down(&f->sem);
146 			}
147 
148 			if (!ret) {
149 				flash_ofs = write_ofs(c);
150 				D1(printk(KERN_DEBUG "Allocated space at 0x%08x to retry failed write.\n", flash_ofs));
151 
152 				jffs2_dbg_acct_sanity_check(c,jeb);
153 				jffs2_dbg_acct_paranoia_check(c, jeb);
154 
155 				goto retry;
156 			}
157 			D1(printk(KERN_DEBUG "Failed to allocate space to retry failed write: %d!\n", ret));
158 		}
159 		/* Release the full_dnode which is now useless, and return */
160 		jffs2_free_full_dnode(fn);
161 		return ERR_PTR(ret?ret:-EIO);
162 	}
163 	/* Mark the space used */
164 	/* If node covers at least a whole page, or if it starts at the
165 	   beginning of a page and runs to the end of the file, or if
166 	   it's a hole node, mark it REF_PRISTINE, else REF_NORMAL.
167 	*/
168 	if ((je32_to_cpu(ri->dsize) >= PAGE_CACHE_SIZE) ||
169 	    ( ((je32_to_cpu(ri->offset)&(PAGE_CACHE_SIZE-1))==0) &&
170 	      (je32_to_cpu(ri->dsize)+je32_to_cpu(ri->offset) ==  je32_to_cpu(ri->isize)))) {
171 		flash_ofs |= REF_PRISTINE;
172 	} else {
173 		flash_ofs |= REF_NORMAL;
174 	}
175 	fn->raw = jffs2_add_physical_node_ref(c, flash_ofs, PAD(sizeof(*ri)+datalen), f->inocache);
176 	if (IS_ERR(fn->raw)) {
177 		void *hold_err = fn->raw;
178 		/* Release the full_dnode which is now useless, and return */
179 		jffs2_free_full_dnode(fn);
180 		return ERR_PTR(PTR_ERR(hold_err));
181 	}
182 	fn->ofs = je32_to_cpu(ri->offset);
183 	fn->size = je32_to_cpu(ri->dsize);
184 	fn->frags = 0;
185 
186 	D1(printk(KERN_DEBUG "jffs2_write_dnode wrote node at 0x%08x(%d) with dsize 0x%x, csize 0x%x, node_crc 0x%08x, data_crc 0x%08x, totlen 0x%08x\n",
187 		  flash_ofs & ~3, flash_ofs & 3, je32_to_cpu(ri->dsize),
188 		  je32_to_cpu(ri->csize), je32_to_cpu(ri->node_crc),
189 		  je32_to_cpu(ri->data_crc), je32_to_cpu(ri->totlen)));
190 
191 	if (retried) {
192 		jffs2_dbg_acct_sanity_check(c,NULL);
193 	}
194 
195 	return fn;
196 }
197 
198 struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
199 					     struct jffs2_raw_dirent *rd, const unsigned char *name,
200 					     uint32_t namelen, int alloc_mode)
201 {
202 	struct jffs2_full_dirent *fd;
203 	size_t retlen;
204 	struct kvec vecs[2];
205 	uint32_t flash_ofs;
206 	int retried = 0;
207 	int ret;
208 
209 	D1(printk(KERN_DEBUG "jffs2_write_dirent(ino #%u, name at *0x%p \"%s\"->ino #%u, name_crc 0x%08x)\n",
210 		  je32_to_cpu(rd->pino), name, name, je32_to_cpu(rd->ino),
211 		  je32_to_cpu(rd->name_crc)));
212 
213 	D1(if(je32_to_cpu(rd->hdr_crc) != crc32(0, rd, sizeof(struct jffs2_unknown_node)-4)) {
214 		printk(KERN_CRIT "Eep. CRC not correct in jffs2_write_dirent()\n");
215 		BUG();
216 	   });
217 
218 	vecs[0].iov_base = rd;
219 	vecs[0].iov_len = sizeof(*rd);
220 	vecs[1].iov_base = (unsigned char *)name;
221 	vecs[1].iov_len = namelen;
222 
223 	fd = jffs2_alloc_full_dirent(namelen+1);
224 	if (!fd)
225 		return ERR_PTR(-ENOMEM);
226 
227 	fd->version = je32_to_cpu(rd->version);
228 	fd->ino = je32_to_cpu(rd->ino);
229 	fd->nhash = full_name_hash(name, strlen(name));
230 	fd->type = rd->type;
231 	memcpy(fd->name, name, namelen);
232 	fd->name[namelen]=0;
233 
234  retry:
235 	flash_ofs = write_ofs(c);
236 
237 	jffs2_dbg_prewrite_paranoia_check(c, flash_ofs, vecs[0].iov_len + vecs[1].iov_len);
238 
239 	if ((alloc_mode!=ALLOC_GC) && (je32_to_cpu(rd->version) < f->highest_version)) {
240 		BUG_ON(!retried);
241 		D1(printk(KERN_DEBUG "jffs2_write_dirent : dirent_version %d, "
242 				     "highest version %d -> updating dirent\n",
243 				     je32_to_cpu(rd->version), f->highest_version));
244 		rd->version = cpu_to_je32(++f->highest_version);
245 		fd->version = je32_to_cpu(rd->version);
246 		rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
247 	}
248 
249 	ret = jffs2_flash_writev(c, vecs, 2, flash_ofs, &retlen,
250 				 (alloc_mode==ALLOC_GC)?0:je32_to_cpu(rd->pino));
251 	if (ret || (retlen != sizeof(*rd) + namelen)) {
252 		printk(KERN_NOTICE "Write of %zd bytes at 0x%08x failed. returned %d, retlen %zd\n",
253 			       sizeof(*rd)+namelen, flash_ofs, ret, retlen);
254 		/* Mark the space as dirtied */
255 		if (retlen) {
256 			jffs2_add_physical_node_ref(c, flash_ofs | REF_OBSOLETE, PAD(sizeof(*rd)+namelen), NULL);
257 		} else {
258 			printk(KERN_NOTICE "Not marking the space at 0x%08x as dirty because the flash driver returned retlen zero\n", flash_ofs);
259 		}
260 		if (!retried) {
261 			/* Try to reallocate space and retry */
262 			uint32_t dummy;
263 			struct jffs2_eraseblock *jeb = &c->blocks[flash_ofs / c->sector_size];
264 
265 			retried = 1;
266 
267 			D1(printk(KERN_DEBUG "Retrying failed write.\n"));
268 
269 			jffs2_dbg_acct_sanity_check(c,jeb);
270 			jffs2_dbg_acct_paranoia_check(c, jeb);
271 
272 			if (alloc_mode == ALLOC_GC) {
273 				ret = jffs2_reserve_space_gc(c, sizeof(*rd) + namelen, &dummy,
274 							     JFFS2_SUMMARY_DIRENT_SIZE(namelen));
275 			} else {
276 				/* Locking pain */
277 				up(&f->sem);
278 				jffs2_complete_reservation(c);
279 
280 				ret = jffs2_reserve_space(c, sizeof(*rd) + namelen, &dummy,
281 							  alloc_mode, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
282 				down(&f->sem);
283 			}
284 
285 			if (!ret) {
286 				flash_ofs = write_ofs(c);
287 				D1(printk(KERN_DEBUG "Allocated space at 0x%08x to retry failed write.\n", flash_ofs));
288 				jffs2_dbg_acct_sanity_check(c,jeb);
289 				jffs2_dbg_acct_paranoia_check(c, jeb);
290 				goto retry;
291 			}
292 			D1(printk(KERN_DEBUG "Failed to allocate space to retry failed write: %d!\n", ret));
293 		}
294 		/* Release the full_dnode which is now useless, and return */
295 		jffs2_free_full_dirent(fd);
296 		return ERR_PTR(ret?ret:-EIO);
297 	}
298 	/* Mark the space used */
299 	fd->raw = jffs2_add_physical_node_ref(c, flash_ofs | REF_PRISTINE, PAD(sizeof(*rd)+namelen), f->inocache);
300 	if (IS_ERR(fd->raw)) {
301 		void *hold_err = fd->raw;
302 		/* Release the full_dirent which is now useless, and return */
303 		jffs2_free_full_dirent(fd);
304 		return ERR_PTR(PTR_ERR(hold_err));
305 	}
306 
307 	if (retried) {
308 		jffs2_dbg_acct_sanity_check(c,NULL);
309 	}
310 
311 	return fd;
312 }
313 
314 /* The OS-specific code fills in the metadata in the jffs2_raw_inode for us, so that
315    we don't have to go digging in struct inode or its equivalent. It should set:
316    mode, uid, gid, (starting)isize, atime, ctime, mtime */
317 int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
318 			    struct jffs2_raw_inode *ri, unsigned char *buf,
319 			    uint32_t offset, uint32_t writelen, uint32_t *retlen)
320 {
321 	int ret = 0;
322 	uint32_t writtenlen = 0;
323 
324        	D1(printk(KERN_DEBUG "jffs2_write_inode_range(): Ino #%u, ofs 0x%x, len 0x%x\n",
325 		  f->inocache->ino, offset, writelen));
326 
327 	while(writelen) {
328 		struct jffs2_full_dnode *fn;
329 		unsigned char *comprbuf = NULL;
330 		uint16_t comprtype = JFFS2_COMPR_NONE;
331 		uint32_t alloclen;
332 		uint32_t datalen, cdatalen;
333 		int retried = 0;
334 
335 	retry:
336 		D2(printk(KERN_DEBUG "jffs2_commit_write() loop: 0x%x to write to 0x%x\n", writelen, offset));
337 
338 		ret = jffs2_reserve_space(c, sizeof(*ri) + JFFS2_MIN_DATA_LEN,
339 					&alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
340 		if (ret) {
341 			D1(printk(KERN_DEBUG "jffs2_reserve_space returned %d\n", ret));
342 			break;
343 		}
344 		down(&f->sem);
345 		datalen = min_t(uint32_t, writelen, PAGE_CACHE_SIZE - (offset & (PAGE_CACHE_SIZE-1)));
346 		cdatalen = min_t(uint32_t, alloclen - sizeof(*ri), datalen);
347 
348 		comprtype = jffs2_compress(c, f, buf, &comprbuf, &datalen, &cdatalen);
349 
350 		ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
351 		ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
352 		ri->totlen = cpu_to_je32(sizeof(*ri) + cdatalen);
353 		ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
354 
355 		ri->ino = cpu_to_je32(f->inocache->ino);
356 		ri->version = cpu_to_je32(++f->highest_version);
357 		ri->isize = cpu_to_je32(max(je32_to_cpu(ri->isize), offset + datalen));
358 		ri->offset = cpu_to_je32(offset);
359 		ri->csize = cpu_to_je32(cdatalen);
360 		ri->dsize = cpu_to_je32(datalen);
361 		ri->compr = comprtype & 0xff;
362 		ri->usercompr = (comprtype >> 8 ) & 0xff;
363 		ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
364 		ri->data_crc = cpu_to_je32(crc32(0, comprbuf, cdatalen));
365 
366 		fn = jffs2_write_dnode(c, f, ri, comprbuf, cdatalen, ALLOC_NORETRY);
367 
368 		jffs2_free_comprbuf(comprbuf, buf);
369 
370 		if (IS_ERR(fn)) {
371 			ret = PTR_ERR(fn);
372 			up(&f->sem);
373 			jffs2_complete_reservation(c);
374 			if (!retried) {
375 				/* Write error to be retried */
376 				retried = 1;
377 				D1(printk(KERN_DEBUG "Retrying node write in jffs2_write_inode_range()\n"));
378 				goto retry;
379 			}
380 			break;
381 		}
382 		ret = jffs2_add_full_dnode_to_inode(c, f, fn);
383 		if (f->metadata) {
384 			jffs2_mark_node_obsolete(c, f->metadata->raw);
385 			jffs2_free_full_dnode(f->metadata);
386 			f->metadata = NULL;
387 		}
388 		if (ret) {
389 			/* Eep */
390 			D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in commit_write, returned %d\n", ret));
391 			jffs2_mark_node_obsolete(c, fn->raw);
392 			jffs2_free_full_dnode(fn);
393 
394 			up(&f->sem);
395 			jffs2_complete_reservation(c);
396 			break;
397 		}
398 		up(&f->sem);
399 		jffs2_complete_reservation(c);
400 		if (!datalen) {
401 			printk(KERN_WARNING "Eep. We didn't actually write any data in jffs2_write_inode_range()\n");
402 			ret = -EIO;
403 			break;
404 		}
405 		D1(printk(KERN_DEBUG "increasing writtenlen by %d\n", datalen));
406 		writtenlen += datalen;
407 		offset += datalen;
408 		writelen -= datalen;
409 		buf += datalen;
410 	}
411 	*retlen = writtenlen;
412 	return ret;
413 }
414 
415 int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f, struct jffs2_raw_inode *ri, const char *name, int namelen)
416 {
417 	struct jffs2_raw_dirent *rd;
418 	struct jffs2_full_dnode *fn;
419 	struct jffs2_full_dirent *fd;
420 	uint32_t alloclen;
421 	int ret;
422 
423 	/* Try to reserve enough space for both node and dirent.
424 	 * Just the node will do for now, though
425 	 */
426 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
427 				JFFS2_SUMMARY_INODE_SIZE);
428 	D1(printk(KERN_DEBUG "jffs2_do_create(): reserved 0x%x bytes\n", alloclen));
429 	if (ret) {
430 		up(&f->sem);
431 		return ret;
432 	}
433 
434 	ri->data_crc = cpu_to_je32(0);
435 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
436 
437 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
438 
439 	D1(printk(KERN_DEBUG "jffs2_do_create created file with mode 0x%x\n",
440 		  jemode_to_cpu(ri->mode)));
441 
442 	if (IS_ERR(fn)) {
443 		D1(printk(KERN_DEBUG "jffs2_write_dnode() failed\n"));
444 		/* Eeek. Wave bye bye */
445 		up(&f->sem);
446 		jffs2_complete_reservation(c);
447 		return PTR_ERR(fn);
448 	}
449 	/* No data here. Only a metadata node, which will be
450 	   obsoleted by the first data write
451 	*/
452 	f->metadata = fn;
453 
454 	up(&f->sem);
455 	jffs2_complete_reservation(c);
456 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
457 				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
458 
459 	if (ret) {
460 		/* Eep. */
461 		D1(printk(KERN_DEBUG "jffs2_reserve_space() for dirent failed\n"));
462 		return ret;
463 	}
464 
465 	rd = jffs2_alloc_raw_dirent();
466 	if (!rd) {
467 		/* Argh. Now we treat it like a normal delete */
468 		jffs2_complete_reservation(c);
469 		return -ENOMEM;
470 	}
471 
472 	down(&dir_f->sem);
473 
474 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
475 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
476 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
477 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
478 
479 	rd->pino = cpu_to_je32(dir_f->inocache->ino);
480 	rd->version = cpu_to_je32(++dir_f->highest_version);
481 	rd->ino = ri->ino;
482 	rd->mctime = ri->ctime;
483 	rd->nsize = namelen;
484 	rd->type = DT_REG;
485 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
486 	rd->name_crc = cpu_to_je32(crc32(0, name, namelen));
487 
488 	fd = jffs2_write_dirent(c, dir_f, rd, name, namelen, ALLOC_NORMAL);
489 
490 	jffs2_free_raw_dirent(rd);
491 
492 	if (IS_ERR(fd)) {
493 		/* dirent failed to write. Delete the inode normally
494 		   as if it were the final unlink() */
495 		jffs2_complete_reservation(c);
496 		up(&dir_f->sem);
497 		return PTR_ERR(fd);
498 	}
499 
500 	/* Link the fd into the inode's list, obsoleting an old
501 	   one if necessary. */
502 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
503 
504 	jffs2_complete_reservation(c);
505 	up(&dir_f->sem);
506 
507 	return 0;
508 }
509 
510 
511 int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f,
512 		    const char *name, int namelen, struct jffs2_inode_info *dead_f,
513 		    uint32_t time)
514 {
515 	struct jffs2_raw_dirent *rd;
516 	struct jffs2_full_dirent *fd;
517 	uint32_t alloclen;
518 	int ret;
519 
520 	if (!jffs2_can_mark_obsolete(c)) {
521 		/* We can't mark stuff obsolete on the medium. We need to write a deletion dirent */
522 
523 		rd = jffs2_alloc_raw_dirent();
524 		if (!rd)
525 			return -ENOMEM;
526 
527 		ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
528 					ALLOC_DELETION, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
529 		if (ret) {
530 			jffs2_free_raw_dirent(rd);
531 			return ret;
532 		}
533 
534 		down(&dir_f->sem);
535 
536 		/* Build a deletion node */
537 		rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
538 		rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
539 		rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
540 		rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
541 
542 		rd->pino = cpu_to_je32(dir_f->inocache->ino);
543 		rd->version = cpu_to_je32(++dir_f->highest_version);
544 		rd->ino = cpu_to_je32(0);
545 		rd->mctime = cpu_to_je32(time);
546 		rd->nsize = namelen;
547 		rd->type = DT_UNKNOWN;
548 		rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
549 		rd->name_crc = cpu_to_je32(crc32(0, name, namelen));
550 
551 		fd = jffs2_write_dirent(c, dir_f, rd, name, namelen, ALLOC_DELETION);
552 
553 		jffs2_free_raw_dirent(rd);
554 
555 		if (IS_ERR(fd)) {
556 			jffs2_complete_reservation(c);
557 			up(&dir_f->sem);
558 			return PTR_ERR(fd);
559 		}
560 
561 		/* File it. This will mark the old one obsolete. */
562 		jffs2_add_fd_to_list(c, fd, &dir_f->dents);
563 		up(&dir_f->sem);
564 	} else {
565 		struct jffs2_full_dirent **prev = &dir_f->dents;
566 		uint32_t nhash = full_name_hash(name, namelen);
567 
568 		down(&dir_f->sem);
569 
570 		while ((*prev) && (*prev)->nhash <= nhash) {
571 			if ((*prev)->nhash == nhash &&
572 			    !memcmp((*prev)->name, name, namelen) &&
573 			    !(*prev)->name[namelen]) {
574 				struct jffs2_full_dirent *this = *prev;
575 
576 				D1(printk(KERN_DEBUG "Marking old dirent node (ino #%u) @%08x obsolete\n",
577 					  this->ino, ref_offset(this->raw)));
578 
579 				*prev = this->next;
580 				jffs2_mark_node_obsolete(c, (this->raw));
581 				jffs2_free_full_dirent(this);
582 				break;
583 			}
584 			prev = &((*prev)->next);
585 		}
586 		up(&dir_f->sem);
587 	}
588 
589 	/* dead_f is NULL if this was a rename not a real unlink */
590 	/* Also catch the !f->inocache case, where there was a dirent
591 	   pointing to an inode which didn't exist. */
592 	if (dead_f && dead_f->inocache) {
593 
594 		down(&dead_f->sem);
595 
596 		if (S_ISDIR(OFNI_EDONI_2SFFJ(dead_f)->i_mode)) {
597 			while (dead_f->dents) {
598 				/* There can be only deleted ones */
599 				fd = dead_f->dents;
600 
601 				dead_f->dents = fd->next;
602 
603 				if (fd->ino) {
604 					printk(KERN_WARNING "Deleting inode #%u with active dentry \"%s\"->ino #%u\n",
605 					       dead_f->inocache->ino, fd->name, fd->ino);
606 				} else {
607 					D1(printk(KERN_DEBUG "Removing deletion dirent for \"%s\" from dir ino #%u\n",
608 						fd->name, dead_f->inocache->ino));
609 				}
610 				jffs2_mark_node_obsolete(c, fd->raw);
611 				jffs2_free_full_dirent(fd);
612 			}
613 		}
614 
615 		dead_f->inocache->nlink--;
616 		/* NB: Caller must set inode nlink if appropriate */
617 		up(&dead_f->sem);
618 	}
619 
620 	jffs2_complete_reservation(c);
621 
622 	return 0;
623 }
624 
625 
626 int jffs2_do_link (struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino, uint8_t type, const char *name, int namelen, uint32_t time)
627 {
628 	struct jffs2_raw_dirent *rd;
629 	struct jffs2_full_dirent *fd;
630 	uint32_t alloclen;
631 	int ret;
632 
633 	rd = jffs2_alloc_raw_dirent();
634 	if (!rd)
635 		return -ENOMEM;
636 
637 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
638 				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
639 	if (ret) {
640 		jffs2_free_raw_dirent(rd);
641 		return ret;
642 	}
643 
644 	down(&dir_f->sem);
645 
646 	/* Build a deletion node */
647 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
648 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
649 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
650 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
651 
652 	rd->pino = cpu_to_je32(dir_f->inocache->ino);
653 	rd->version = cpu_to_je32(++dir_f->highest_version);
654 	rd->ino = cpu_to_je32(ino);
655 	rd->mctime = cpu_to_je32(time);
656 	rd->nsize = namelen;
657 
658 	rd->type = type;
659 
660 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
661 	rd->name_crc = cpu_to_je32(crc32(0, name, namelen));
662 
663 	fd = jffs2_write_dirent(c, dir_f, rd, name, namelen, ALLOC_NORMAL);
664 
665 	jffs2_free_raw_dirent(rd);
666 
667 	if (IS_ERR(fd)) {
668 		jffs2_complete_reservation(c);
669 		up(&dir_f->sem);
670 		return PTR_ERR(fd);
671 	}
672 
673 	/* File it. This will mark the old one obsolete. */
674 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
675 
676 	jffs2_complete_reservation(c);
677 	up(&dir_f->sem);
678 
679 	return 0;
680 }
681