libata: always use polling SETXFER
[sfrench/cifs-2.6.git] / fs / jffs2 / xattr.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2006  NEC Corporation
5  *
6  * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/fs.h>
15 #include <linux/time.h>
16 #include <linux/pagemap.h>
17 #include <linux/highmem.h>
18 #include <linux/crc32.h>
19 #include <linux/jffs2.h>
20 #include <linux/xattr.h>
21 #include <linux/mtd/mtd.h>
22 #include "nodelist.h"
23 /* -------- xdatum related functions ----------------
24  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
25  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
26  *   the index of the xattr name/value pair cache (c->xattrindex).
27  * is_xattr_datum_unchecked(c, xd)
28  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
29  *   unchecked, it returns 0.
30  * unload_xattr_datum(c, xd)
31  *   is used to release xattr name/value pair and detach from c->xattrindex.
32  * reclaim_xattr_datum(c)
33  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
34  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold 
35  *   is hard coded as 32KiB.
36  * do_verify_xattr_datum(c, xd)
37  *   is used to load the xdatum informations without name/value pair from the medium.
38  *   It's necessary once, because those informations are not collected during mounting
39  *   process when EBS is enabled.
40  *   0 will be returned, if success. An negative return value means recoverable error, and
41  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
42  *   and xref when it returned positive value.
43  * do_load_xattr_datum(c, xd)
44  *   is used to load name/value pair from the medium.
45  *   The meanings of return value is same as do_verify_xattr_datum().
46  * load_xattr_datum(c, xd)
47  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
48  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
49  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
50  * save_xattr_datum(c, xd)
51  *   is used to write xdatum to medium. xd->version will be incremented.
52  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
53  *   is used to create new xdatum and write to medium.
54  * unrefer_xattr_datum(c, xd)
55  *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
56  *   is set on xd->flags and chained xattr_dead_list or release it immediately.
57  *   In the first case, the garbage collector release it later.
58  * -------------------------------------------------- */
59 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
60 {
61         int name_len = strlen(xname);
62
63         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
64 }
65
66 static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
67 {
68         struct jffs2_raw_node_ref *raw;
69         int rc = 0;
70
71         spin_lock(&c->erase_completion_lock);
72         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
73                 if (ref_flags(raw) == REF_UNCHECKED) {
74                         rc = 1;
75                         break;
76                 }
77         }
78         spin_unlock(&c->erase_completion_lock);
79         return rc;
80 }
81
82 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
83 {
84         /* must be called under down_write(xattr_sem) */
85         D1(dbg_xattr("%s: xid=%u, version=%u\n", __FUNCTION__, xd->xid, xd->version));
86         if (xd->xname) {
87                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
88                 kfree(xd->xname);
89         }
90
91         list_del_init(&xd->xindex);
92         xd->hashkey = 0;
93         xd->xname = NULL;
94         xd->xvalue = NULL;
95 }
96
97 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
98 {
99         /* must be called under down_write(xattr_sem) */
100         struct jffs2_xattr_datum *xd, *_xd;
101         uint32_t target, before;
102         static int index = 0;
103         int count;
104
105         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
106                 return;
107
108         before = c->xdatum_mem_usage;
109         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
110         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
111                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
112                         if (xd->flags & JFFS2_XFLAGS_HOT) {
113                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
114                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
115                                 unload_xattr_datum(c, xd);
116                         }
117                         if (c->xdatum_mem_usage <= target)
118                                 goto out;
119                 }
120                 index = (index+1) % XATTRINDEX_HASHSIZE;
121         }
122  out:
123         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
124                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
125 }
126
127 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
128 {
129         /* must be called under down_write(xattr_sem) */
130         struct jffs2_eraseblock *jeb;
131         struct jffs2_raw_node_ref *raw;
132         struct jffs2_raw_xattr rx;
133         size_t readlen;
134         uint32_t crc, offset, totlen;
135         int rc;
136
137         spin_lock(&c->erase_completion_lock);
138         offset = ref_offset(xd->node);
139         if (ref_flags(xd->node) == REF_PRISTINE)
140                 goto complete;
141         spin_unlock(&c->erase_completion_lock);
142
143         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
144         if (rc || readlen != sizeof(rx)) {
145                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
146                               rc, sizeof(rx), readlen, offset);
147                 return rc ? rc : -EIO;
148         }
149         crc = crc32(0, &rx, sizeof(rx) - 4);
150         if (crc != je32_to_cpu(rx.node_crc)) {
151                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
152                             offset, je32_to_cpu(rx.hdr_crc), crc);
153                 xd->flags |= JFFS2_XFLAGS_INVALID;
154                 return EIO;
155         }
156         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
157         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
158             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
159             || je32_to_cpu(rx.totlen) != totlen
160             || je32_to_cpu(rx.xid) != xd->xid
161             || je32_to_cpu(rx.version) != xd->version) {
162                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
163                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
164                             offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
165                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
166                             je32_to_cpu(rx.totlen), totlen,
167                             je32_to_cpu(rx.xid), xd->xid,
168                             je32_to_cpu(rx.version), xd->version);
169                 xd->flags |= JFFS2_XFLAGS_INVALID;
170                 return EIO;
171         }
172         xd->xprefix = rx.xprefix;
173         xd->name_len = rx.name_len;
174         xd->value_len = je16_to_cpu(rx.value_len);
175         xd->data_crc = je32_to_cpu(rx.data_crc);
176
177         spin_lock(&c->erase_completion_lock);
178  complete:
179         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
180                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
181                 totlen = PAD(ref_totlen(c, jeb, raw));
182                 if (ref_flags(raw) == REF_UNCHECKED) {
183                         c->unchecked_size -= totlen; c->used_size += totlen;
184                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
185                 }
186                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
187         }
188         spin_unlock(&c->erase_completion_lock);
189
190         /* unchecked xdatum is chained with c->xattr_unchecked */
191         list_del_init(&xd->xindex);
192
193         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
194                   xd->xid, xd->version);
195
196         return 0;
197 }
198
199 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
200 {
201         /* must be called under down_write(xattr_sem) */
202         char *data;
203         size_t readlen;
204         uint32_t crc, length;
205         int i, ret, retry = 0;
206
207         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
208         BUG_ON(!list_empty(&xd->xindex));
209  retry:
210         length = xd->name_len + 1 + xd->value_len;
211         data = kmalloc(length, GFP_KERNEL);
212         if (!data)
213                 return -ENOMEM;
214
215         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
216                                length, &readlen, data);
217
218         if (ret || length!=readlen) {
219                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
220                               ret, length, readlen, ref_offset(xd->node));
221                 kfree(data);
222                 return ret ? ret : -EIO;
223         }
224
225         data[xd->name_len] = '\0';
226         crc = crc32(0, data, length);
227         if (crc != xd->data_crc) {
228                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
229                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
230                               ref_offset(xd->node), xd->data_crc, crc);
231                 kfree(data);
232                 xd->flags |= JFFS2_XFLAGS_INVALID;
233                 return EIO;
234         }
235
236         xd->flags |= JFFS2_XFLAGS_HOT;
237         xd->xname = data;
238         xd->xvalue = data + xd->name_len+1;
239
240         c->xdatum_mem_usage += length;
241
242         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
243         i = xd->hashkey % XATTRINDEX_HASHSIZE;
244         list_add(&xd->xindex, &c->xattrindex[i]);
245         if (!retry) {
246                 retry = 1;
247                 reclaim_xattr_datum(c);
248                 if (!xd->xname)
249                         goto retry;
250         }
251
252         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
253                   xd->xid, xd->xprefix, xd->xname);
254
255         return 0;
256 }
257
258 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
259 {
260         /* must be called under down_write(xattr_sem);
261          * rc < 0 : recoverable error, try again
262          * rc = 0 : success
263          * rc > 0 : Unrecoverable error, this node should be deleted.
264          */
265         int rc = 0;
266
267         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
268         if (xd->xname)
269                 return 0;
270         if (xd->flags & JFFS2_XFLAGS_INVALID)
271                 return EIO;
272         if (unlikely(is_xattr_datum_unchecked(c, xd)))
273                 rc = do_verify_xattr_datum(c, xd);
274         if (!rc)
275                 rc = do_load_xattr_datum(c, xd);
276         return rc;
277 }
278
279 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
280 {
281         /* must be called under down_write(xattr_sem) */
282         struct jffs2_raw_xattr rx;
283         struct kvec vecs[2];
284         size_t length;
285         int rc, totlen;
286         uint32_t phys_ofs = write_ofs(c);
287
288         BUG_ON(!xd->xname);
289         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
290
291         vecs[0].iov_base = &rx;
292         vecs[0].iov_len = sizeof(rx);
293         vecs[1].iov_base = xd->xname;
294         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
295         totlen = vecs[0].iov_len + vecs[1].iov_len;
296
297         /* Setup raw-xattr */
298         memset(&rx, 0, sizeof(rx));
299         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
300         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
301         rx.totlen = cpu_to_je32(PAD(totlen));
302         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
303
304         rx.xid = cpu_to_je32(xd->xid);
305         rx.version = cpu_to_je32(++xd->version);
306         rx.xprefix = xd->xprefix;
307         rx.name_len = xd->name_len;
308         rx.value_len = cpu_to_je16(xd->value_len);
309         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
310         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
311
312         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
313         if (rc || totlen != length) {
314                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
315                               rc, totlen, length, phys_ofs);
316                 rc = rc ? rc : -EIO;
317                 if (length)
318                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
319
320                 return rc;
321         }
322         /* success */
323         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
324
325         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
326                   xd->xid, xd->version, xd->xprefix, xd->xname);
327
328         return 0;
329 }
330
331 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
332                                                     int xprefix, const char *xname,
333                                                     const char *xvalue, int xsize)
334 {
335         /* must be called under down_write(xattr_sem) */
336         struct jffs2_xattr_datum *xd;
337         uint32_t hashkey, name_len;
338         char *data;
339         int i, rc;
340
341         /* Search xattr_datum has same xname/xvalue by index */
342         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
343         i = hashkey % XATTRINDEX_HASHSIZE;
344         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
345                 if (xd->hashkey==hashkey
346                     && xd->xprefix==xprefix
347                     && xd->value_len==xsize
348                     && !strcmp(xd->xname, xname)
349                     && !memcmp(xd->xvalue, xvalue, xsize)) {
350                         atomic_inc(&xd->refcnt);
351                         return xd;
352                 }
353         }
354
355         /* Not found, Create NEW XATTR-Cache */
356         name_len = strlen(xname);
357
358         xd = jffs2_alloc_xattr_datum();
359         if (!xd)
360                 return ERR_PTR(-ENOMEM);
361
362         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
363         if (!data) {
364                 jffs2_free_xattr_datum(xd);
365                 return ERR_PTR(-ENOMEM);
366         }
367         strcpy(data, xname);
368         memcpy(data + name_len + 1, xvalue, xsize);
369
370         atomic_set(&xd->refcnt, 1);
371         xd->xid = ++c->highest_xid;
372         xd->flags |= JFFS2_XFLAGS_HOT;
373         xd->xprefix = xprefix;
374
375         xd->hashkey = hashkey;
376         xd->xname = data;
377         xd->xvalue = data + name_len + 1;
378         xd->name_len = name_len;
379         xd->value_len = xsize;
380         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
381
382         rc = save_xattr_datum(c, xd);
383         if (rc) {
384                 kfree(xd->xname);
385                 jffs2_free_xattr_datum(xd);
386                 return ERR_PTR(rc);
387         }
388
389         /* Insert Hash Index */
390         i = hashkey % XATTRINDEX_HASHSIZE;
391         list_add(&xd->xindex, &c->xattrindex[i]);
392
393         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
394         reclaim_xattr_datum(c);
395
396         return xd;
397 }
398
399 static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
400 {
401         /* must be called under down_write(xattr_sem) */
402         if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
403                 unload_xattr_datum(c, xd);
404                 xd->flags |= JFFS2_XFLAGS_DEAD;
405                 if (xd->node == (void *)xd) {
406                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
407                         jffs2_free_xattr_datum(xd);
408                 } else {
409                         list_add(&xd->xindex, &c->xattr_dead_list);
410                 }
411                 spin_unlock(&c->erase_completion_lock);
412
413                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
414                           xd->xid, xd->version);
415         }
416 }
417
418 /* -------- xref related functions ------------------
419  * verify_xattr_ref(c, ref)
420  *   is used to load xref information from medium. Because summary data does not
421  *   contain xid/ino, it's necessary to verify once while mounting process.
422  * save_xattr_ref(c, ref)
423  *   is used to write xref to medium. If delete marker is marked, it write
424  *   a delete marker of xref into medium.
425  * create_xattr_ref(c, ic, xd)
426  *   is used to create a new xref and write to medium.
427  * delete_xattr_ref(c, ref)
428  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
429  *   and allows GC to reclaim those physical nodes.
430  * jffs2_xattr_delete_inode(c, ic)
431  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
432  * jffs2_xattr_free_inode(c, ic)
433  *   is called to release xattr related objects when unmounting. 
434  * check_xattr_ref_inode(c, ic)
435  *   is used to confirm inode does not have duplicate xattr name/value pair.
436  * -------------------------------------------------- */
437 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
438 {
439         struct jffs2_eraseblock *jeb;
440         struct jffs2_raw_node_ref *raw;
441         struct jffs2_raw_xref rr;
442         size_t readlen;
443         uint32_t crc, offset, totlen;
444         int rc;
445
446         spin_lock(&c->erase_completion_lock);
447         if (ref_flags(ref->node) != REF_UNCHECKED)
448                 goto complete;
449         offset = ref_offset(ref->node);
450         spin_unlock(&c->erase_completion_lock);
451
452         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
453         if (rc || sizeof(rr) != readlen) {
454                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
455                               rc, sizeof(rr), readlen, offset);
456                 return rc ? rc : -EIO;
457         }
458         /* obsolete node */
459         crc = crc32(0, &rr, sizeof(rr) - 4);
460         if (crc != je32_to_cpu(rr.node_crc)) {
461                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
462                             offset, je32_to_cpu(rr.node_crc), crc);
463                 return EIO;
464         }
465         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
466             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
467             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
468                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
469                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
470                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
471                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
472                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
473                 return EIO;
474         }
475         ref->ino = je32_to_cpu(rr.ino);
476         ref->xid = je32_to_cpu(rr.xid);
477         ref->xseqno = je32_to_cpu(rr.xseqno);
478         if (ref->xseqno > c->highest_xseqno)
479                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
480
481         spin_lock(&c->erase_completion_lock);
482  complete:
483         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
484                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
485                 totlen = PAD(ref_totlen(c, jeb, raw));
486                 if (ref_flags(raw) == REF_UNCHECKED) {
487                         c->unchecked_size -= totlen; c->used_size += totlen;
488                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
489                 }
490                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
491         }
492         spin_unlock(&c->erase_completion_lock);
493
494         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
495                   ref->ino, ref->xid, ref_offset(ref->node));
496         return 0;
497 }
498
499 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
500 {
501         /* must be called under down_write(xattr_sem) */
502         struct jffs2_raw_xref rr;
503         size_t length;
504         uint32_t xseqno, phys_ofs = write_ofs(c);
505         int ret;
506
507         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
508         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
509         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
510         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
511
512         xseqno = (c->highest_xseqno += 2);
513         if (is_xattr_ref_dead(ref)) {
514                 xseqno |= XREF_DELETE_MARKER;
515                 rr.ino = cpu_to_je32(ref->ino);
516                 rr.xid = cpu_to_je32(ref->xid);
517         } else {
518                 rr.ino = cpu_to_je32(ref->ic->ino);
519                 rr.xid = cpu_to_je32(ref->xd->xid);
520         }
521         rr.xseqno = cpu_to_je32(xseqno);
522         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
523
524         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
525         if (ret || sizeof(rr) != length) {
526                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
527                               ret, sizeof(rr), length, phys_ofs);
528                 ret = ret ? ret : -EIO;
529                 if (length)
530                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
531
532                 return ret;
533         }
534         /* success */
535         ref->xseqno = xseqno;
536         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
537
538         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
539
540         return 0;
541 }
542
543 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
544                                                 struct jffs2_xattr_datum *xd)
545 {
546         /* must be called under down_write(xattr_sem) */
547         struct jffs2_xattr_ref *ref;
548         int ret;
549
550         ref = jffs2_alloc_xattr_ref();
551         if (!ref)
552                 return ERR_PTR(-ENOMEM);
553         ref->ic = ic;
554         ref->xd = xd;
555
556         ret = save_xattr_ref(c, ref);
557         if (ret) {
558                 jffs2_free_xattr_ref(ref);
559                 return ERR_PTR(ret);
560         }
561
562         /* Chain to inode */
563         ref->next = ic->xref;
564         ic->xref = ref;
565
566         return ref; /* success */
567 }
568
569 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
570 {
571         /* must be called under down_write(xattr_sem) */
572         struct jffs2_xattr_datum *xd;
573
574         xd = ref->xd;
575         ref->xseqno |= XREF_DELETE_MARKER;
576         ref->ino = ref->ic->ino;
577         ref->xid = ref->xd->xid;
578         spin_lock(&c->erase_completion_lock);
579         ref->next = c->xref_dead_list;
580         c->xref_dead_list = ref;
581         spin_unlock(&c->erase_completion_lock);
582
583         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
584                   ref->ino, ref->xid, ref->xseqno);
585
586         unrefer_xattr_datum(c, xd);
587 }
588
589 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
590 {
591         /* It's called from jffs2_clear_inode() on inode removing.
592            When an inode with XATTR is removed, those XATTRs must be removed. */
593         struct jffs2_xattr_ref *ref, *_ref;
594
595         if (!ic || ic->nlink > 0)
596                 return;
597
598         down_write(&c->xattr_sem);
599         for (ref = ic->xref; ref; ref = _ref) {
600                 _ref = ref->next;
601                 delete_xattr_ref(c, ref);
602         }
603         ic->xref = NULL;
604         up_write(&c->xattr_sem);
605 }
606
607 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
608 {
609         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
610         struct jffs2_xattr_datum *xd;
611         struct jffs2_xattr_ref *ref, *_ref;
612
613         down_write(&c->xattr_sem);
614         for (ref = ic->xref; ref; ref = _ref) {
615                 _ref = ref->next;
616                 xd = ref->xd;
617                 if (atomic_dec_and_test(&xd->refcnt)) {
618                         unload_xattr_datum(c, xd);
619                         jffs2_free_xattr_datum(xd);
620                 }
621                 jffs2_free_xattr_ref(ref);
622         }
623         ic->xref = NULL;
624         up_write(&c->xattr_sem);
625 }
626
627 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
628 {
629         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
630          * duplicate name/value pairs. If duplicate name/value pair would be found,
631          * one will be removed.
632          */
633         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
634         int rc = 0;
635
636         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
637                 return 0;
638         down_write(&c->xattr_sem);
639  retry:
640         rc = 0;
641         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
642                 if (!ref->xd->xname) {
643                         rc = load_xattr_datum(c, ref->xd);
644                         if (unlikely(rc > 0)) {
645                                 *pref = ref->next;
646                                 delete_xattr_ref(c, ref);
647                                 goto retry;
648                         } else if (unlikely(rc < 0))
649                                 goto out;
650                 }
651                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
652                         if (!cmp->xd->xname) {
653                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
654                                 rc = load_xattr_datum(c, cmp->xd);
655                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
656                                 if (unlikely(rc > 0)) {
657                                         *pcmp = cmp->next;
658                                         delete_xattr_ref(c, cmp);
659                                         goto retry;
660                                 } else if (unlikely(rc < 0))
661                                         goto out;
662                         }
663                         if (ref->xd->xprefix == cmp->xd->xprefix
664                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
665                                 if (ref->xseqno > cmp->xseqno) {
666                                         *pcmp = cmp->next;
667                                         delete_xattr_ref(c, cmp);
668                                 } else {
669                                         *pref = ref->next;
670                                         delete_xattr_ref(c, ref);
671                                 }
672                                 goto retry;
673                         }
674                 }
675         }
676         ic->flags |= INO_FLAGS_XATTR_CHECKED;
677  out:
678         up_write(&c->xattr_sem);
679
680         return rc;
681 }
682
683 /* -------- xattr subsystem functions ---------------
684  * jffs2_init_xattr_subsystem(c)
685  *   is used to initialize semaphore and list_head, and some variables.
686  * jffs2_find_xattr_datum(c, xid)
687  *   is used to lookup xdatum while scanning process.
688  * jffs2_clear_xattr_subsystem(c)
689  *   is used to release any xattr related objects.
690  * jffs2_build_xattr_subsystem(c)
691  *   is used to associate xdatum and xref while super block building process.
692  * jffs2_setup_xattr_datum(c, xid, version)
693  *   is used to insert xdatum while scanning process.
694  * -------------------------------------------------- */
695 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
696 {
697         int i;
698
699         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
700                 INIT_LIST_HEAD(&c->xattrindex[i]);
701         INIT_LIST_HEAD(&c->xattr_unchecked);
702         INIT_LIST_HEAD(&c->xattr_dead_list);
703         c->xref_dead_list = NULL;
704         c->xref_temp = NULL;
705
706         init_rwsem(&c->xattr_sem);
707         c->highest_xid = 0;
708         c->highest_xseqno = 0;
709         c->xdatum_mem_usage = 0;
710         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
711 }
712
713 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
714 {
715         struct jffs2_xattr_datum *xd;
716         int i = xid % XATTRINDEX_HASHSIZE;
717
718         /* It's only used in scanning/building process. */
719         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
720
721         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
722                 if (xd->xid==xid)
723                         return xd;
724         }
725         return NULL;
726 }
727
728 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
729 {
730         struct jffs2_xattr_datum *xd, *_xd;
731         struct jffs2_xattr_ref *ref, *_ref;
732         int i;
733
734         for (ref=c->xref_temp; ref; ref = _ref) {
735                 _ref = ref->next;
736                 jffs2_free_xattr_ref(ref);
737         }
738
739         for (ref=c->xref_dead_list; ref; ref = _ref) {
740                 _ref = ref->next;
741                 jffs2_free_xattr_ref(ref);
742         }
743
744         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
745                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
746                         list_del(&xd->xindex);
747                         if (xd->xname)
748                                 kfree(xd->xname);
749                         jffs2_free_xattr_datum(xd);
750                 }
751         }
752
753         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
754                 list_del(&xd->xindex);
755                 jffs2_free_xattr_datum(xd);
756         }
757 }
758
759 #define XREF_TMPHASH_SIZE       (128)
760 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
761 {
762         struct jffs2_xattr_ref *ref, *_ref;
763         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
764         struct jffs2_xattr_datum *xd, *_xd;
765         struct jffs2_inode_cache *ic;
766         struct jffs2_raw_node_ref *raw;
767         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
768         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
769
770         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
771
772         /* Phase.1 : Merge same xref */
773         for (i=0; i < XREF_TMPHASH_SIZE; i++)
774                 xref_tmphash[i] = NULL;
775         for (ref=c->xref_temp; ref; ref=_ref) {
776                 struct jffs2_xattr_ref *tmp;
777
778                 _ref = ref->next;
779                 if (ref_flags(ref->node) != REF_PRISTINE) {
780                         if (verify_xattr_ref(c, ref)) {
781                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
782                                 ref->node->next_in_ino = NULL;
783                                 jffs2_mark_node_obsolete(c, ref->node);
784                                 jffs2_free_xattr_ref(ref);
785                                 continue;
786                         }
787                 }
788
789                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
790                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
791                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
792                                 break;
793                 }
794                 if (tmp) {
795                         raw = ref->node;
796                         if (ref->xseqno > tmp->xseqno) {
797                                 tmp->xseqno = ref->xseqno;
798                                 raw->next_in_ino = tmp->node;
799                                 tmp->node = raw;
800                         } else {
801                                 raw->next_in_ino = tmp->node->next_in_ino;
802                                 tmp->node->next_in_ino = raw;
803                         }
804                         jffs2_free_xattr_ref(ref);
805                         continue;
806                 } else {
807                         ref->next = xref_tmphash[i];
808                         xref_tmphash[i] = ref;
809                 }
810         }
811         c->xref_temp = NULL;
812
813         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
814         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
815                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
816                         xref_count++;
817                         _ref = ref->next;
818                         if (is_xattr_ref_dead(ref)) {
819                                 ref->next = c->xref_dead_list;
820                                 c->xref_dead_list = ref;
821                                 xref_dead_count++;
822                                 continue;
823                         }
824                         /* At this point, ref->xid and ref->ino contain XID and inode number.
825                            ref->xd and ref->ic are not valid yet. */
826                         xd = jffs2_find_xattr_datum(c, ref->xid);
827                         ic = jffs2_get_ino_cache(c, ref->ino);
828                         if (!xd || !ic) {
829                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
830                                           ref->ino, ref->xid, ref->xseqno);
831                                 ref->xseqno |= XREF_DELETE_MARKER;
832                                 ref->next = c->xref_dead_list;
833                                 c->xref_dead_list = ref;
834                                 xref_orphan_count++;
835                                 continue;
836                         }
837                         ref->xd = xd;
838                         ref->ic = ic;
839                         atomic_inc(&xd->refcnt);
840                         ref->next = ic->xref;
841                         ic->xref = ref;
842                 }
843         }
844
845         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
846         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
847                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
848                         xdatum_count++;
849                         list_del_init(&xd->xindex);
850                         if (!atomic_read(&xd->refcnt)) {
851                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
852                                           xd->xid, xd->version);
853                                 xd->flags |= JFFS2_XFLAGS_DEAD;
854                                 list_add(&xd->xindex, &c->xattr_unchecked);
855                                 xdatum_orphan_count++;
856                                 continue;
857                         }
858                         if (is_xattr_datum_unchecked(c, xd)) {
859                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
860                                           xd->xid, xd->version);
861                                 list_add(&xd->xindex, &c->xattr_unchecked);
862                                 xdatum_unchecked_count++;
863                         }
864                 }
865         }
866         /* build complete */
867         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
868                      " (%u unchecked, %u orphan) and "
869                      "%u of xref (%u dead, %u orphan) found.\n",
870                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
871                      xref_count, xref_dead_count, xref_orphan_count);
872 }
873
874 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
875                                                   uint32_t xid, uint32_t version)
876 {
877         struct jffs2_xattr_datum *xd;
878
879         xd = jffs2_find_xattr_datum(c, xid);
880         if (!xd) {
881                 xd = jffs2_alloc_xattr_datum();
882                 if (!xd)
883                         return ERR_PTR(-ENOMEM);
884                 xd->xid = xid;
885                 xd->version = version;
886                 if (xd->xid > c->highest_xid)
887                         c->highest_xid = xd->xid;
888                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
889         }
890         return xd;
891 }
892
893 /* -------- xattr subsystem functions ---------------
894  * xprefix_to_handler(xprefix)
895  *   is used to translate xprefix into xattr_handler.
896  * jffs2_listxattr(dentry, buffer, size)
897  *   is an implementation of listxattr handler on jffs2.
898  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
899  *   is an implementation of getxattr handler on jffs2.
900  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
901  *   is an implementation of setxattr handler on jffs2.
902  * -------------------------------------------------- */
903 struct xattr_handler *jffs2_xattr_handlers[] = {
904         &jffs2_user_xattr_handler,
905 #ifdef CONFIG_JFFS2_FS_SECURITY
906         &jffs2_security_xattr_handler,
907 #endif
908 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
909         &jffs2_acl_access_xattr_handler,
910         &jffs2_acl_default_xattr_handler,
911 #endif
912         &jffs2_trusted_xattr_handler,
913         NULL
914 };
915
916 static struct xattr_handler *xprefix_to_handler(int xprefix) {
917         struct xattr_handler *ret;
918
919         switch (xprefix) {
920         case JFFS2_XPREFIX_USER:
921                 ret = &jffs2_user_xattr_handler;
922                 break;
923 #ifdef CONFIG_JFFS2_FS_SECURITY
924         case JFFS2_XPREFIX_SECURITY:
925                 ret = &jffs2_security_xattr_handler;
926                 break;
927 #endif
928 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
929         case JFFS2_XPREFIX_ACL_ACCESS:
930                 ret = &jffs2_acl_access_xattr_handler;
931                 break;
932         case JFFS2_XPREFIX_ACL_DEFAULT:
933                 ret = &jffs2_acl_default_xattr_handler;
934                 break;
935 #endif
936         case JFFS2_XPREFIX_TRUSTED:
937                 ret = &jffs2_trusted_xattr_handler;
938                 break;
939         default:
940                 ret = NULL;
941                 break;
942         }
943         return ret;
944 }
945
946 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
947 {
948         struct inode *inode = dentry->d_inode;
949         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
950         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
951         struct jffs2_inode_cache *ic = f->inocache;
952         struct jffs2_xattr_ref *ref, **pref;
953         struct jffs2_xattr_datum *xd;
954         struct xattr_handler *xhandle;
955         ssize_t len, rc;
956         int retry = 0;
957
958         rc = check_xattr_ref_inode(c, ic);
959         if (unlikely(rc))
960                 return rc;
961
962         down_read(&c->xattr_sem);
963  retry:
964         len = 0;
965         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
966                 BUG_ON(ref->ic != ic);
967                 xd = ref->xd;
968                 if (!xd->xname) {
969                         /* xdatum is unchached */
970                         if (!retry) {
971                                 retry = 1;
972                                 up_read(&c->xattr_sem);
973                                 down_write(&c->xattr_sem);
974                                 goto retry;
975                         } else {
976                                 rc = load_xattr_datum(c, xd);
977                                 if (unlikely(rc > 0)) {
978                                         *pref = ref->next;
979                                         delete_xattr_ref(c, ref);
980                                         goto retry;
981                                 } else if (unlikely(rc < 0))
982                                         goto out;
983                         }
984                 }
985                 xhandle = xprefix_to_handler(xd->xprefix);
986                 if (!xhandle)
987                         continue;
988                 if (buffer) {
989                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
990                 } else {
991                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
992                 }
993                 if (rc < 0)
994                         goto out;
995                 len += rc;
996         }
997         rc = len;
998  out:
999         if (!retry) {
1000                 up_read(&c->xattr_sem);
1001         } else {
1002                 up_write(&c->xattr_sem);
1003         }
1004         return rc;
1005 }
1006
1007 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1008                       char *buffer, size_t size)
1009 {
1010         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1011         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1012         struct jffs2_inode_cache *ic = f->inocache;
1013         struct jffs2_xattr_datum *xd;
1014         struct jffs2_xattr_ref *ref, **pref;
1015         int rc, retry = 0;
1016
1017         rc = check_xattr_ref_inode(c, ic);
1018         if (unlikely(rc))
1019                 return rc;
1020
1021         down_read(&c->xattr_sem);
1022  retry:
1023         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1024                 BUG_ON(ref->ic!=ic);
1025
1026                 xd = ref->xd;
1027                 if (xd->xprefix != xprefix)
1028                         continue;
1029                 if (!xd->xname) {
1030                         /* xdatum is unchached */
1031                         if (!retry) {
1032                                 retry = 1;
1033                                 up_read(&c->xattr_sem);
1034                                 down_write(&c->xattr_sem);
1035                                 goto retry;
1036                         } else {
1037                                 rc = load_xattr_datum(c, xd);
1038                                 if (unlikely(rc > 0)) {
1039                                         *pref = ref->next;
1040                                         delete_xattr_ref(c, ref);
1041                                         goto retry;
1042                                 } else if (unlikely(rc < 0)) {
1043                                         goto out;
1044                                 }
1045                         }
1046                 }
1047                 if (!strcmp(xname, xd->xname)) {
1048                         rc = xd->value_len;
1049                         if (buffer) {
1050                                 if (size < rc) {
1051                                         rc = -ERANGE;
1052                                 } else {
1053                                         memcpy(buffer, xd->xvalue, rc);
1054                                 }
1055                         }
1056                         goto out;
1057                 }
1058         }
1059         rc = -ENODATA;
1060  out:
1061         if (!retry) {
1062                 up_read(&c->xattr_sem);
1063         } else {
1064                 up_write(&c->xattr_sem);
1065         }
1066         return rc;
1067 }
1068
1069 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1070                       const char *buffer, size_t size, int flags)
1071 {
1072         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1073         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1074         struct jffs2_inode_cache *ic = f->inocache;
1075         struct jffs2_xattr_datum *xd;
1076         struct jffs2_xattr_ref *ref, *newref, **pref;
1077         uint32_t length, request;
1078         int rc;
1079
1080         rc = check_xattr_ref_inode(c, ic);
1081         if (unlikely(rc))
1082                 return rc;
1083
1084         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1085         rc = jffs2_reserve_space(c, request, &length,
1086                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1087         if (rc) {
1088                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1089                 return rc;
1090         }
1091
1092         /* Find existing xattr */
1093         down_write(&c->xattr_sem);
1094  retry:
1095         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1096                 xd = ref->xd;
1097                 if (xd->xprefix != xprefix)
1098                         continue;
1099                 if (!xd->xname) {
1100                         rc = load_xattr_datum(c, xd);
1101                         if (unlikely(rc > 0)) {
1102                                 *pref = ref->next;
1103                                 delete_xattr_ref(c, ref);
1104                                 goto retry;
1105                         } else if (unlikely(rc < 0))
1106                                 goto out;
1107                 }
1108                 if (!strcmp(xd->xname, xname)) {
1109                         if (flags & XATTR_CREATE) {
1110                                 rc = -EEXIST;
1111                                 goto out;
1112                         }
1113                         if (!buffer) {
1114                                 ref->ino = ic->ino;
1115                                 ref->xid = xd->xid;
1116                                 ref->xseqno |= XREF_DELETE_MARKER;
1117                                 rc = save_xattr_ref(c, ref);
1118                                 if (!rc) {
1119                                         *pref = ref->next;
1120                                         spin_lock(&c->erase_completion_lock);
1121                                         ref->next = c->xref_dead_list;
1122                                         c->xref_dead_list = ref;
1123                                         spin_unlock(&c->erase_completion_lock);
1124                                         unrefer_xattr_datum(c, xd);
1125                                 } else {
1126                                         ref->ic = ic;
1127                                         ref->xd = xd;
1128                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1129                                 }
1130                                 goto out;
1131                         }
1132                         goto found;
1133                 }
1134         }
1135         /* not found */
1136         if (flags & XATTR_REPLACE) {
1137                 rc = -ENODATA;
1138                 goto out;
1139         }
1140         if (!buffer) {
1141                 rc = -ENODATA;
1142                 goto out;
1143         }
1144  found:
1145         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1146         if (IS_ERR(xd)) {
1147                 rc = PTR_ERR(xd);
1148                 goto out;
1149         }
1150         up_write(&c->xattr_sem);
1151         jffs2_complete_reservation(c);
1152
1153         /* create xattr_ref */
1154         request = PAD(sizeof(struct jffs2_raw_xref));
1155         rc = jffs2_reserve_space(c, request, &length,
1156                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1157         down_write(&c->xattr_sem);
1158         if (rc) {
1159                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1160                 unrefer_xattr_datum(c, xd);
1161                 up_write(&c->xattr_sem);
1162                 return rc;
1163         }
1164         if (ref)
1165                 *pref = ref->next;
1166         newref = create_xattr_ref(c, ic, xd);
1167         if (IS_ERR(newref)) {
1168                 if (ref) {
1169                         ref->next = ic->xref;
1170                         ic->xref = ref;
1171                 }
1172                 rc = PTR_ERR(newref);
1173                 unrefer_xattr_datum(c, xd);
1174         } else if (ref) {
1175                 delete_xattr_ref(c, ref);
1176         }
1177  out:
1178         up_write(&c->xattr_sem);
1179         jffs2_complete_reservation(c);
1180         return rc;
1181 }
1182
1183 /* -------- garbage collector functions -------------
1184  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1185  *   is used to move xdatum into new node.
1186  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1187  *   is used to move xref into new node.
1188  * jffs2_verify_xattr(c)
1189  *   is used to call do_verify_xattr_datum() before garbage collecting.
1190  * jffs2_release_xattr_datum(c, xd)
1191  *   is used to release an in-memory object of xdatum.
1192  * jffs2_release_xattr_ref(c, ref)
1193  *   is used to release an in-memory object of xref.
1194  * -------------------------------------------------- */
1195 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1196                                       struct jffs2_raw_node_ref *raw)
1197 {
1198         uint32_t totlen, length, old_ofs;
1199         int rc = 0;
1200
1201         down_write(&c->xattr_sem);
1202         if (xd->node != raw)
1203                 goto out;
1204         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1205                 goto out;
1206
1207         rc = load_xattr_datum(c, xd);
1208         if (unlikely(rc)) {
1209                 rc = (rc > 0) ? 0 : rc;
1210                 goto out;
1211         }
1212         old_ofs = ref_offset(xd->node);
1213         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1214                         + xd->name_len + 1 + xd->value_len);
1215         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1216         if (rc) {
1217                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1218                 goto out;
1219         }
1220         rc = save_xattr_datum(c, xd);
1221         if (!rc)
1222                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1223                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1224  out:
1225         if (!rc)
1226                 jffs2_mark_node_obsolete(c, raw);
1227         up_write(&c->xattr_sem);
1228         return rc;
1229 }
1230
1231 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1232                                     struct jffs2_raw_node_ref *raw)
1233 {
1234         uint32_t totlen, length, old_ofs;
1235         int rc = 0;
1236
1237         down_write(&c->xattr_sem);
1238         BUG_ON(!ref->node);
1239
1240         if (ref->node != raw)
1241                 goto out;
1242         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1243                 goto out;
1244
1245         old_ofs = ref_offset(ref->node);
1246         totlen = ref_totlen(c, c->gcblock, ref->node);
1247
1248         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1249         if (rc) {
1250                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1251                               __FUNCTION__, rc, totlen);
1252                 rc = rc ? rc : -EBADFD;
1253                 goto out;
1254         }
1255         rc = save_xattr_ref(c, ref);
1256         if (!rc)
1257                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1258                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1259  out:
1260         if (!rc)
1261                 jffs2_mark_node_obsolete(c, raw);
1262         up_write(&c->xattr_sem);
1263         return rc;
1264 }
1265
1266 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1267 {
1268         struct jffs2_xattr_datum *xd, *_xd;
1269         struct jffs2_eraseblock *jeb;
1270         struct jffs2_raw_node_ref *raw;
1271         uint32_t totlen;
1272         int rc;
1273
1274         down_write(&c->xattr_sem);
1275         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1276                 rc = do_verify_xattr_datum(c, xd);
1277                 if (rc < 0)
1278                         continue;
1279                 list_del_init(&xd->xindex);
1280                 spin_lock(&c->erase_completion_lock);
1281                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1282                         if (ref_flags(raw) != REF_UNCHECKED)
1283                                 continue;
1284                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1285                         totlen = PAD(ref_totlen(c, jeb, raw));
1286                         c->unchecked_size -= totlen; c->used_size += totlen;
1287                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1288                         raw->flash_offset = ref_offset(raw)
1289                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1290                 }
1291                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1292                         list_add(&xd->xindex, &c->xattr_dead_list);
1293                 spin_unlock(&c->erase_completion_lock);
1294         }
1295         up_write(&c->xattr_sem);
1296         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1297 }
1298
1299 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1300 {
1301         /* must be called under spin_lock(&c->erase_completion_lock) */
1302         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1303                 return;
1304
1305         list_del(&xd->xindex);
1306         jffs2_free_xattr_datum(xd);
1307 }
1308
1309 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1310 {
1311         /* must be called under spin_lock(&c->erase_completion_lock) */
1312         struct jffs2_xattr_ref *tmp, **ptmp;
1313
1314         if (ref->node != (void *)ref)
1315                 return;
1316
1317         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1318                 if (ref == tmp) {
1319                         *ptmp = tmp->next;
1320                         break;
1321                 }
1322         }
1323         jffs2_free_xattr_ref(ref);
1324 }