~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/jffs2/xattr.c

Version: ~ [ linux-5.2-rc1 ] ~ [ linux-5.1.2 ] ~ [ linux-5.0.16 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.43 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.119 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.176 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.179 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.139 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.67 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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. Currently, 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", __func__, 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_evict_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->pino_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 that 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         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
758                 list_del(&xd->xindex);
759                 jffs2_free_xattr_datum(xd);
760         }
761 }
762 
763 #define XREF_TMPHASH_SIZE       (128)
764 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
765 {
766         struct jffs2_xattr_ref *ref, *_ref;
767         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
768         struct jffs2_xattr_datum *xd, *_xd;
769         struct jffs2_inode_cache *ic;
770         struct jffs2_raw_node_ref *raw;
771         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
772         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
773 
774         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
775 
776         /* Phase.1 : Merge same xref */
777         for (i=0; i < XREF_TMPHASH_SIZE; i++)
778                 xref_tmphash[i] = NULL;
779         for (ref=c->xref_temp; ref; ref=_ref) {
780                 struct jffs2_xattr_ref *tmp;
781 
782                 _ref = ref->next;
783                 if (ref_flags(ref->node) != REF_PRISTINE) {
784                         if (verify_xattr_ref(c, ref)) {
785                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
786                                 ref->node->next_in_ino = NULL;
787                                 jffs2_mark_node_obsolete(c, ref->node);
788                                 jffs2_free_xattr_ref(ref);
789                                 continue;
790                         }
791                 }
792 
793                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
794                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
795                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
796                                 break;
797                 }
798                 if (tmp) {
799                         raw = ref->node;
800                         if (ref->xseqno > tmp->xseqno) {
801                                 tmp->xseqno = ref->xseqno;
802                                 raw->next_in_ino = tmp->node;
803                                 tmp->node = raw;
804                         } else {
805                                 raw->next_in_ino = tmp->node->next_in_ino;
806                                 tmp->node->next_in_ino = raw;
807                         }
808                         jffs2_free_xattr_ref(ref);
809                         continue;
810                 } else {
811                         ref->next = xref_tmphash[i];
812                         xref_tmphash[i] = ref;
813                 }
814         }
815         c->xref_temp = NULL;
816 
817         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
818         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
819                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
820                         xref_count++;
821                         _ref = ref->next;
822                         if (is_xattr_ref_dead(ref)) {
823                                 ref->next = c->xref_dead_list;
824                                 c->xref_dead_list = ref;
825                                 xref_dead_count++;
826                                 continue;
827                         }
828                         /* At this point, ref->xid and ref->ino contain XID and inode number.
829                            ref->xd and ref->ic are not valid yet. */
830                         xd = jffs2_find_xattr_datum(c, ref->xid);
831                         ic = jffs2_get_ino_cache(c, ref->ino);
832                         if (!xd || !ic || !ic->pino_nlink) {
833                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
834                                           ref->ino, ref->xid, ref->xseqno);
835                                 ref->xseqno |= XREF_DELETE_MARKER;
836                                 ref->next = c->xref_dead_list;
837                                 c->xref_dead_list = ref;
838                                 xref_orphan_count++;
839                                 continue;
840                         }
841                         ref->xd = xd;
842                         ref->ic = ic;
843                         atomic_inc(&xd->refcnt);
844                         ref->next = ic->xref;
845                         ic->xref = ref;
846                 }
847         }
848 
849         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
850         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
851                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
852                         xdatum_count++;
853                         list_del_init(&xd->xindex);
854                         if (!atomic_read(&xd->refcnt)) {
855                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
856                                           xd->xid, xd->version);
857                                 xd->flags |= JFFS2_XFLAGS_DEAD;
858                                 list_add(&xd->xindex, &c->xattr_unchecked);
859                                 xdatum_orphan_count++;
860                                 continue;
861                         }
862                         if (is_xattr_datum_unchecked(c, xd)) {
863                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
864                                           xd->xid, xd->version);
865                                 list_add(&xd->xindex, &c->xattr_unchecked);
866                                 xdatum_unchecked_count++;
867                         }
868                 }
869         }
870         /* build complete */
871         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
872                      " (%u unchecked, %u orphan) and "
873                      "%u of xref (%u dead, %u orphan) found.\n",
874                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
875                      xref_count, xref_dead_count, xref_orphan_count);
876 }
877 
878 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
879                                                   uint32_t xid, uint32_t version)
880 {
881         struct jffs2_xattr_datum *xd;
882 
883         xd = jffs2_find_xattr_datum(c, xid);
884         if (!xd) {
885                 xd = jffs2_alloc_xattr_datum();
886                 if (!xd)
887                         return ERR_PTR(-ENOMEM);
888                 xd->xid = xid;
889                 xd->version = version;
890                 if (xd->xid > c->highest_xid)
891                         c->highest_xid = xd->xid;
892                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
893         }
894         return xd;
895 }
896 
897 /* -------- xattr subsystem functions ---------------
898  * xprefix_to_handler(xprefix)
899  *   is used to translate xprefix into xattr_handler.
900  * jffs2_listxattr(dentry, buffer, size)
901  *   is an implementation of listxattr handler on jffs2.
902  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
903  *   is an implementation of getxattr handler on jffs2.
904  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
905  *   is an implementation of setxattr handler on jffs2.
906  * -------------------------------------------------- */
907 const struct xattr_handler *jffs2_xattr_handlers[] = {
908         &jffs2_user_xattr_handler,
909 #ifdef CONFIG_JFFS2_FS_SECURITY
910         &jffs2_security_xattr_handler,
911 #endif
912 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
913         &jffs2_acl_access_xattr_handler,
914         &jffs2_acl_default_xattr_handler,
915 #endif
916         &jffs2_trusted_xattr_handler,
917         NULL
918 };
919 
920 static const struct xattr_handler *xprefix_to_handler(int xprefix) {
921         const struct xattr_handler *ret;
922 
923         switch (xprefix) {
924         case JFFS2_XPREFIX_USER:
925                 ret = &jffs2_user_xattr_handler;
926                 break;
927 #ifdef CONFIG_JFFS2_FS_SECURITY
928         case JFFS2_XPREFIX_SECURITY:
929                 ret = &jffs2_security_xattr_handler;
930                 break;
931 #endif
932 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
933         case JFFS2_XPREFIX_ACL_ACCESS:
934                 ret = &jffs2_acl_access_xattr_handler;
935                 break;
936         case JFFS2_XPREFIX_ACL_DEFAULT:
937                 ret = &jffs2_acl_default_xattr_handler;
938                 break;
939 #endif
940         case JFFS2_XPREFIX_TRUSTED:
941                 ret = &jffs2_trusted_xattr_handler;
942                 break;
943         default:
944                 ret = NULL;
945                 break;
946         }
947         return ret;
948 }
949 
950 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
951 {
952         struct inode *inode = dentry->d_inode;
953         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
954         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
955         struct jffs2_inode_cache *ic = f->inocache;
956         struct jffs2_xattr_ref *ref, **pref;
957         struct jffs2_xattr_datum *xd;
958         const struct xattr_handler *xhandle;
959         ssize_t len, rc;
960         int retry = 0;
961 
962         rc = check_xattr_ref_inode(c, ic);
963         if (unlikely(rc))
964                 return rc;
965 
966         down_read(&c->xattr_sem);
967  retry:
968         len = 0;
969         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
970                 BUG_ON(ref->ic != ic);
971                 xd = ref->xd;
972                 if (!xd->xname) {
973                         /* xdatum is unchached */
974                         if (!retry) {
975                                 retry = 1;
976                                 up_read(&c->xattr_sem);
977                                 down_write(&c->xattr_sem);
978                                 goto retry;
979                         } else {
980                                 rc = load_xattr_datum(c, xd);
981                                 if (unlikely(rc > 0)) {
982                                         *pref = ref->next;
983                                         delete_xattr_ref(c, ref);
984                                         goto retry;
985                                 } else if (unlikely(rc < 0))
986                                         goto out;
987                         }
988                 }
989                 xhandle = xprefix_to_handler(xd->xprefix);
990                 if (!xhandle)
991                         continue;
992                 if (buffer) {
993                         rc = xhandle->list(dentry, buffer+len, size-len,
994                                            xd->xname, xd->name_len, xd->flags);
995                 } else {
996                         rc = xhandle->list(dentry, NULL, 0, xd->xname,
997                                            xd->name_len, xd->flags);
998                 }
999                 if (rc < 0)
1000                         goto out;
1001                 len += rc;
1002         }
1003         rc = len;
1004  out:
1005         if (!retry) {
1006                 up_read(&c->xattr_sem);
1007         } else {
1008                 up_write(&c->xattr_sem);
1009         }
1010         return rc;
1011 }
1012 
1013 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1014                       char *buffer, size_t size)
1015 {
1016         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1017         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1018         struct jffs2_inode_cache *ic = f->inocache;
1019         struct jffs2_xattr_datum *xd;
1020         struct jffs2_xattr_ref *ref, **pref;
1021         int rc, retry = 0;
1022 
1023         rc = check_xattr_ref_inode(c, ic);
1024         if (unlikely(rc))
1025                 return rc;
1026 
1027         down_read(&c->xattr_sem);
1028  retry:
1029         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1030                 BUG_ON(ref->ic!=ic);
1031 
1032                 xd = ref->xd;
1033                 if (xd->xprefix != xprefix)
1034                         continue;
1035                 if (!xd->xname) {
1036                         /* xdatum is unchached */
1037                         if (!retry) {
1038                                 retry = 1;
1039                                 up_read(&c->xattr_sem);
1040                                 down_write(&c->xattr_sem);
1041                                 goto retry;
1042                         } else {
1043                                 rc = load_xattr_datum(c, xd);
1044                                 if (unlikely(rc > 0)) {
1045                                         *pref = ref->next;
1046                                         delete_xattr_ref(c, ref);
1047                                         goto retry;
1048                                 } else if (unlikely(rc < 0)) {
1049                                         goto out;
1050                                 }
1051                         }
1052                 }
1053                 if (!strcmp(xname, xd->xname)) {
1054                         rc = xd->value_len;
1055                         if (buffer) {
1056                                 if (size < rc) {
1057                                         rc = -ERANGE;
1058                                 } else {
1059                                         memcpy(buffer, xd->xvalue, rc);
1060                                 }
1061                         }
1062                         goto out;
1063                 }
1064         }
1065         rc = -ENODATA;
1066  out:
1067         if (!retry) {
1068                 up_read(&c->xattr_sem);
1069         } else {
1070                 up_write(&c->xattr_sem);
1071         }
1072         return rc;
1073 }
1074 
1075 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1076                       const char *buffer, size_t size, int flags)
1077 {
1078         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1079         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1080         struct jffs2_inode_cache *ic = f->inocache;
1081         struct jffs2_xattr_datum *xd;
1082         struct jffs2_xattr_ref *ref, *newref, **pref;
1083         uint32_t length, request;
1084         int rc;
1085 
1086         rc = check_xattr_ref_inode(c, ic);
1087         if (unlikely(rc))
1088                 return rc;
1089 
1090         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1091         rc = jffs2_reserve_space(c, request, &length,
1092                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1093         if (rc) {
1094                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1095                 return rc;
1096         }
1097 
1098         /* Find existing xattr */
1099         down_write(&c->xattr_sem);
1100  retry:
1101         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1102                 xd = ref->xd;
1103                 if (xd->xprefix != xprefix)
1104                         continue;
1105                 if (!xd->xname) {
1106                         rc = load_xattr_datum(c, xd);
1107                         if (unlikely(rc > 0)) {
1108                                 *pref = ref->next;
1109                                 delete_xattr_ref(c, ref);
1110                                 goto retry;
1111                         } else if (unlikely(rc < 0))
1112                                 goto out;
1113                 }
1114                 if (!strcmp(xd->xname, xname)) {
1115                         if (flags & XATTR_CREATE) {
1116                                 rc = -EEXIST;
1117                                 goto out;
1118                         }
1119                         if (!buffer) {
1120                                 ref->ino = ic->ino;
1121                                 ref->xid = xd->xid;
1122                                 ref->xseqno |= XREF_DELETE_MARKER;
1123                                 rc = save_xattr_ref(c, ref);
1124                                 if (!rc) {
1125                                         *pref = ref->next;
1126                                         spin_lock(&c->erase_completion_lock);
1127                                         ref->next = c->xref_dead_list;
1128                                         c->xref_dead_list = ref;
1129                                         spin_unlock(&c->erase_completion_lock);
1130                                         unrefer_xattr_datum(c, xd);
1131                                 } else {
1132                                         ref->ic = ic;
1133                                         ref->xd = xd;
1134                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1135                                 }
1136                                 goto out;
1137                         }
1138                         goto found;
1139                 }
1140         }
1141         /* not found */
1142         if (flags & XATTR_REPLACE) {
1143                 rc = -ENODATA;
1144                 goto out;
1145         }
1146         if (!buffer) {
1147                 rc = -ENODATA;
1148                 goto out;
1149         }
1150  found:
1151         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1152         if (IS_ERR(xd)) {
1153                 rc = PTR_ERR(xd);
1154                 goto out;
1155         }
1156         up_write(&c->xattr_sem);
1157         jffs2_complete_reservation(c);
1158 
1159         /* create xattr_ref */
1160         request = PAD(sizeof(struct jffs2_raw_xref));
1161         rc = jffs2_reserve_space(c, request, &length,
1162                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1163         down_write(&c->xattr_sem);
1164         if (rc) {
1165                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1166                 unrefer_xattr_datum(c, xd);
1167                 up_write(&c->xattr_sem);
1168                 return rc;
1169         }
1170         if (ref)
1171                 *pref = ref->next;
1172         newref = create_xattr_ref(c, ic, xd);
1173         if (IS_ERR(newref)) {
1174                 if (ref) {
1175                         ref->next = ic->xref;
1176                         ic->xref = ref;
1177                 }
1178                 rc = PTR_ERR(newref);
1179                 unrefer_xattr_datum(c, xd);
1180         } else if (ref) {
1181                 delete_xattr_ref(c, ref);
1182         }
1183  out:
1184         up_write(&c->xattr_sem);
1185         jffs2_complete_reservation(c);
1186         return rc;
1187 }
1188 
1189 /* -------- garbage collector functions -------------
1190  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1191  *   is used to move xdatum into new node.
1192  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1193  *   is used to move xref into new node.
1194  * jffs2_verify_xattr(c)
1195  *   is used to call do_verify_xattr_datum() before garbage collecting.
1196  * jffs2_release_xattr_datum(c, xd)
1197  *   is used to release an in-memory object of xdatum.
1198  * jffs2_release_xattr_ref(c, ref)
1199  *   is used to release an in-memory object of xref.
1200  * -------------------------------------------------- */
1201 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1202                                       struct jffs2_raw_node_ref *raw)
1203 {
1204         uint32_t totlen, length, old_ofs;
1205         int rc = 0;
1206 
1207         down_write(&c->xattr_sem);
1208         if (xd->node != raw)
1209                 goto out;
1210         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1211                 goto out;
1212 
1213         rc = load_xattr_datum(c, xd);
1214         if (unlikely(rc)) {
1215                 rc = (rc > 0) ? 0 : rc;
1216                 goto out;
1217         }
1218         old_ofs = ref_offset(xd->node);
1219         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1220                         + xd->name_len + 1 + xd->value_len);
1221         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1222         if (rc) {
1223                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1224                 goto out;
1225         }
1226         rc = save_xattr_datum(c, xd);
1227         if (!rc)
1228                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1229                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1230  out:
1231         if (!rc)
1232                 jffs2_mark_node_obsolete(c, raw);
1233         up_write(&c->xattr_sem);
1234         return rc;
1235 }
1236 
1237 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1238                                     struct jffs2_raw_node_ref *raw)
1239 {
1240         uint32_t totlen, length, old_ofs;
1241         int rc = 0;
1242 
1243         down_write(&c->xattr_sem);
1244         BUG_ON(!ref->node);
1245 
1246         if (ref->node != raw)
1247                 goto out;
1248         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1249                 goto out;
1250 
1251         old_ofs = ref_offset(ref->node);
1252         totlen = ref_totlen(c, c->gcblock, ref->node);
1253 
1254         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1255         if (rc) {
1256                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1257                               __func__, rc, totlen);
1258                 rc = rc ? rc : -EBADFD;
1259                 goto out;
1260         }
1261         rc = save_xattr_ref(c, ref);
1262         if (!rc)
1263                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1264                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1265  out:
1266         if (!rc)
1267                 jffs2_mark_node_obsolete(c, raw);
1268         up_write(&c->xattr_sem);
1269         return rc;
1270 }
1271 
1272 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1273 {
1274         struct jffs2_xattr_datum *xd, *_xd;
1275         struct jffs2_eraseblock *jeb;
1276         struct jffs2_raw_node_ref *raw;
1277         uint32_t totlen;
1278         int rc;
1279 
1280         down_write(&c->xattr_sem);
1281         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1282                 rc = do_verify_xattr_datum(c, xd);
1283                 if (rc < 0)
1284                         continue;
1285                 list_del_init(&xd->xindex);
1286                 spin_lock(&c->erase_completion_lock);
1287                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1288                         if (ref_flags(raw) != REF_UNCHECKED)
1289                                 continue;
1290                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1291                         totlen = PAD(ref_totlen(c, jeb, raw));
1292                         c->unchecked_size -= totlen; c->used_size += totlen;
1293                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1294                         raw->flash_offset = ref_offset(raw)
1295                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1296                 }
1297                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1298                         list_add(&xd->xindex, &c->xattr_dead_list);
1299                 spin_unlock(&c->erase_completion_lock);
1300         }
1301         up_write(&c->xattr_sem);
1302         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1303 }
1304 
1305 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1306 {
1307         /* must be called under spin_lock(&c->erase_completion_lock) */
1308         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1309                 return;
1310 
1311         list_del(&xd->xindex);
1312         jffs2_free_xattr_datum(xd);
1313 }
1314 
1315 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1316 {
1317         /* must be called under spin_lock(&c->erase_completion_lock) */
1318         struct jffs2_xattr_ref *tmp, **ptmp;
1319 
1320         if (ref->node != (void *)ref)
1321                 return;
1322 
1323         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1324                 if (ref == tmp) {
1325                         *ptmp = tmp->next;
1326                         break;
1327                 }
1328         }
1329         jffs2_free_xattr_ref(ref);
1330 }
1331 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp