Root/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 * -------------------------------------------------- */
59static 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
66static 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
82static 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
97static 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
127static 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
199static 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
258static 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
279static 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
331static 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
399static 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 * -------------------------------------------------- */
437static 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
499static 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
543static 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
569static 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
589void 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->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
607void 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
627static 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 * -------------------------------------------------- */
695void 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
713static 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
728void 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)
764void 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
878struct 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 * -------------------------------------------------- */
907struct 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
920static struct xattr_handler *xprefix_to_handler(int xprefix) {
921    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
950ssize_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    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(inode, buffer+len, size-len, xd->xname, xd->name_len);
994        } else {
995            rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
996        }
997        if (rc < 0)
998            goto out;
999        len += rc;
1000    }
1001    rc = len;
1002 out:
1003    if (!retry) {
1004        up_read(&c->xattr_sem);
1005    } else {
1006        up_write(&c->xattr_sem);
1007    }
1008    return rc;
1009}
1010
1011int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1012              char *buffer, size_t size)
1013{
1014    struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1015    struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1016    struct jffs2_inode_cache *ic = f->inocache;
1017    struct jffs2_xattr_datum *xd;
1018    struct jffs2_xattr_ref *ref, **pref;
1019    int rc, retry = 0;
1020
1021    rc = check_xattr_ref_inode(c, ic);
1022    if (unlikely(rc))
1023        return rc;
1024
1025    down_read(&c->xattr_sem);
1026 retry:
1027    for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1028        BUG_ON(ref->ic!=ic);
1029
1030        xd = ref->xd;
1031        if (xd->xprefix != xprefix)
1032            continue;
1033        if (!xd->xname) {
1034            /* xdatum is unchached */
1035            if (!retry) {
1036                retry = 1;
1037                up_read(&c->xattr_sem);
1038                down_write(&c->xattr_sem);
1039                goto retry;
1040            } else {
1041                rc = load_xattr_datum(c, xd);
1042                if (unlikely(rc > 0)) {
1043                    *pref = ref->next;
1044                    delete_xattr_ref(c, ref);
1045                    goto retry;
1046                } else if (unlikely(rc < 0)) {
1047                    goto out;
1048                }
1049            }
1050        }
1051        if (!strcmp(xname, xd->xname)) {
1052            rc = xd->value_len;
1053            if (buffer) {
1054                if (size < rc) {
1055                    rc = -ERANGE;
1056                } else {
1057                    memcpy(buffer, xd->xvalue, rc);
1058                }
1059            }
1060            goto out;
1061        }
1062    }
1063    rc = -ENODATA;
1064 out:
1065    if (!retry) {
1066        up_read(&c->xattr_sem);
1067    } else {
1068        up_write(&c->xattr_sem);
1069    }
1070    return rc;
1071}
1072
1073int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1074              const char *buffer, size_t size, int flags)
1075{
1076    struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1077    struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1078    struct jffs2_inode_cache *ic = f->inocache;
1079    struct jffs2_xattr_datum *xd;
1080    struct jffs2_xattr_ref *ref, *newref, **pref;
1081    uint32_t length, request;
1082    int rc;
1083
1084    rc = check_xattr_ref_inode(c, ic);
1085    if (unlikely(rc))
1086        return rc;
1087
1088    request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1089    rc = jffs2_reserve_space(c, request, &length,
1090                 ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1091    if (rc) {
1092        JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1093        return rc;
1094    }
1095
1096    /* Find existing xattr */
1097    down_write(&c->xattr_sem);
1098 retry:
1099    for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1100        xd = ref->xd;
1101        if (xd->xprefix != xprefix)
1102            continue;
1103        if (!xd->xname) {
1104            rc = load_xattr_datum(c, xd);
1105            if (unlikely(rc > 0)) {
1106                *pref = ref->next;
1107                delete_xattr_ref(c, ref);
1108                goto retry;
1109            } else if (unlikely(rc < 0))
1110                goto out;
1111        }
1112        if (!strcmp(xd->xname, xname)) {
1113            if (flags & XATTR_CREATE) {
1114                rc = -EEXIST;
1115                goto out;
1116            }
1117            if (!buffer) {
1118                ref->ino = ic->ino;
1119                ref->xid = xd->xid;
1120                ref->xseqno |= XREF_DELETE_MARKER;
1121                rc = save_xattr_ref(c, ref);
1122                if (!rc) {
1123                    *pref = ref->next;
1124                    spin_lock(&c->erase_completion_lock);
1125                    ref->next = c->xref_dead_list;
1126                    c->xref_dead_list = ref;
1127                    spin_unlock(&c->erase_completion_lock);
1128                    unrefer_xattr_datum(c, xd);
1129                } else {
1130                    ref->ic = ic;
1131                    ref->xd = xd;
1132                    ref->xseqno &= ~XREF_DELETE_MARKER;
1133                }
1134                goto out;
1135            }
1136            goto found;
1137        }
1138    }
1139    /* not found */
1140    if (flags & XATTR_REPLACE) {
1141        rc = -ENODATA;
1142        goto out;
1143    }
1144    if (!buffer) {
1145        rc = -ENODATA;
1146        goto out;
1147    }
1148 found:
1149    xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1150    if (IS_ERR(xd)) {
1151        rc = PTR_ERR(xd);
1152        goto out;
1153    }
1154    up_write(&c->xattr_sem);
1155    jffs2_complete_reservation(c);
1156
1157    /* create xattr_ref */
1158    request = PAD(sizeof(struct jffs2_raw_xref));
1159    rc = jffs2_reserve_space(c, request, &length,
1160                 ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1161    down_write(&c->xattr_sem);
1162    if (rc) {
1163        JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1164        unrefer_xattr_datum(c, xd);
1165        up_write(&c->xattr_sem);
1166        return rc;
1167    }
1168    if (ref)
1169        *pref = ref->next;
1170    newref = create_xattr_ref(c, ic, xd);
1171    if (IS_ERR(newref)) {
1172        if (ref) {
1173            ref->next = ic->xref;
1174            ic->xref = ref;
1175        }
1176        rc = PTR_ERR(newref);
1177        unrefer_xattr_datum(c, xd);
1178    } else if (ref) {
1179        delete_xattr_ref(c, ref);
1180    }
1181 out:
1182    up_write(&c->xattr_sem);
1183    jffs2_complete_reservation(c);
1184    return rc;
1185}
1186
1187/* -------- garbage collector functions -------------
1188 * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1189 * is used to move xdatum into new node.
1190 * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1191 * is used to move xref into new node.
1192 * jffs2_verify_xattr(c)
1193 * is used to call do_verify_xattr_datum() before garbage collecting.
1194 * jffs2_release_xattr_datum(c, xd)
1195 * is used to release an in-memory object of xdatum.
1196 * jffs2_release_xattr_ref(c, ref)
1197 * is used to release an in-memory object of xref.
1198 * -------------------------------------------------- */
1199int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1200                      struct jffs2_raw_node_ref *raw)
1201{
1202    uint32_t totlen, length, old_ofs;
1203    int rc = 0;
1204
1205    down_write(&c->xattr_sem);
1206    if (xd->node != raw)
1207        goto out;
1208    if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1209        goto out;
1210
1211    rc = load_xattr_datum(c, xd);
1212    if (unlikely(rc)) {
1213        rc = (rc > 0) ? 0 : rc;
1214        goto out;
1215    }
1216    old_ofs = ref_offset(xd->node);
1217    totlen = PAD(sizeof(struct jffs2_raw_xattr)
1218            + xd->name_len + 1 + xd->value_len);
1219    rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1220    if (rc) {
1221        JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1222        goto out;
1223    }
1224    rc = save_xattr_datum(c, xd);
1225    if (!rc)
1226        dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1227              xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1228 out:
1229    if (!rc)
1230        jffs2_mark_node_obsolete(c, raw);
1231    up_write(&c->xattr_sem);
1232    return rc;
1233}
1234
1235int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1236                    struct jffs2_raw_node_ref *raw)
1237{
1238    uint32_t totlen, length, old_ofs;
1239    int rc = 0;
1240
1241    down_write(&c->xattr_sem);
1242    BUG_ON(!ref->node);
1243
1244    if (ref->node != raw)
1245        goto out;
1246    if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1247        goto out;
1248
1249    old_ofs = ref_offset(ref->node);
1250    totlen = ref_totlen(c, c->gcblock, ref->node);
1251
1252    rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1253    if (rc) {
1254        JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1255                  __func__, rc, totlen);
1256        rc = rc ? rc : -EBADFD;
1257        goto out;
1258    }
1259    rc = save_xattr_ref(c, ref);
1260    if (!rc)
1261        dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1262              ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1263 out:
1264    if (!rc)
1265        jffs2_mark_node_obsolete(c, raw);
1266    up_write(&c->xattr_sem);
1267    return rc;
1268}
1269
1270int jffs2_verify_xattr(struct jffs2_sb_info *c)
1271{
1272    struct jffs2_xattr_datum *xd, *_xd;
1273    struct jffs2_eraseblock *jeb;
1274    struct jffs2_raw_node_ref *raw;
1275    uint32_t totlen;
1276    int rc;
1277
1278    down_write(&c->xattr_sem);
1279    list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1280        rc = do_verify_xattr_datum(c, xd);
1281        if (rc < 0)
1282            continue;
1283        list_del_init(&xd->xindex);
1284        spin_lock(&c->erase_completion_lock);
1285        for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1286            if (ref_flags(raw) != REF_UNCHECKED)
1287                continue;
1288            jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1289            totlen = PAD(ref_totlen(c, jeb, raw));
1290            c->unchecked_size -= totlen; c->used_size += totlen;
1291            jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1292            raw->flash_offset = ref_offset(raw)
1293                | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1294        }
1295        if (xd->flags & JFFS2_XFLAGS_DEAD)
1296            list_add(&xd->xindex, &c->xattr_dead_list);
1297        spin_unlock(&c->erase_completion_lock);
1298    }
1299    up_write(&c->xattr_sem);
1300    return list_empty(&c->xattr_unchecked) ? 1 : 0;
1301}
1302
1303void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1304{
1305    /* must be called under spin_lock(&c->erase_completion_lock) */
1306    if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1307        return;
1308
1309    list_del(&xd->xindex);
1310    jffs2_free_xattr_datum(xd);
1311}
1312
1313void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1314{
1315    /* must be called under spin_lock(&c->erase_completion_lock) */
1316    struct jffs2_xattr_ref *tmp, **ptmp;
1317
1318    if (ref->node != (void *)ref)
1319        return;
1320
1321    for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1322        if (ref == tmp) {
1323            *ptmp = tmp->next;
1324            break;
1325        }
1326    }
1327    jffs2_free_xattr_ref(ref);
1328}
1329

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