aboutsummaryrefslogtreecommitdiffstats
path: root/fs/jffs2
diff options
context:
space:
mode:
authorDavid Woodhouse <dwmw2@infradead.org>2007-07-11 09:23:54 -0400
committerDavid Woodhouse <dwmw2@infradead.org>2007-07-11 09:23:54 -0400
commita6bc432e296dfa1f05d4b586ca5ca3085a2d42d7 (patch)
treedb51669fcc74686efb4c65f98938907d76202ffa /fs/jffs2
parentef53cb02ffee8ceb44ea75f778f77eace6b9c89a (diff)
[JFFS2] Add support for write-buffer verification.
We've seen some evil corruption issues, where the corruption seems to be introduced after the JFFS2 crc32 is calculated but before the NAND controller calculates the ECC. So it's in RAM or in the PCI DMA transfer; not on the flash. Attempt to catch it earlier by (optionally) reading back from the flash immediately after writing it. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'fs/jffs2')
-rw-r--r--fs/jffs2/jffs2_fs_sb.h3
-rw-r--r--fs/jffs2/wbuf.c73
2 files changed, 66 insertions, 10 deletions
diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index b13298a824ed..ae99cd7fd43b 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -106,6 +106,9 @@ struct jffs2_sb_info {
106 106
107 uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */ 107 uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
108 108
109#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
110 unsigned char *wbuf_verify; /* read-back buffer for verification */
111#endif
109#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 112#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
110 unsigned char *wbuf; /* Write-behind buffer for NAND flash */ 113 unsigned char *wbuf; /* Write-behind buffer for NAND flash */
111 uint32_t wbuf_ofs; 114 uint32_t wbuf_ofs;
diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 64f8d7add7e8..ec99c8ec83ae 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -220,6 +220,47 @@ static struct jffs2_raw_node_ref **jffs2_incore_replace_raw(struct jffs2_sb_info
220 return NULL; 220 return NULL;
221} 221}
222 222
223#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
224static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf,
225 uint32_t ofs)
226{
227 int ret;
228 size_t retlen;
229 char *eccstr;
230
231 ret = c->mtd->read(c->mtd, ofs, c->wbuf_pagesize, &retlen, c->wbuf_verify);
232 if (ret && ret != -EUCLEAN && ret != -EBADMSG) {
233 printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x failed: %d\n", c->wbuf_ofs, ret);
234 return ret;
235 } else if (retlen != c->wbuf_pagesize) {
236 printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x gave short read: %zd not %d.\n", ofs, retlen, c->wbuf_pagesize);
237 return -EIO;
238 }
239 if (!memcmp(buf, c->wbuf_verify, c->wbuf_pagesize))
240 return 0;
241
242 if (ret == -EUCLEAN)
243 eccstr = "corrected";
244 else if (ret == -EBADMSG)
245 eccstr = "correction failed";
246 else
247 eccstr = "OK or unused";
248
249 printk(KERN_WARNING "Write verify error (ECC %s) at %08x. Wrote:\n",
250 eccstr, c->wbuf_ofs);
251 print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
252 c->wbuf, c->wbuf_pagesize, 0);
253
254 printk(KERN_WARNING "Read back:\n");
255 print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
256 c->wbuf_verify, c->wbuf_pagesize, 0);
257
258 return -EIO;
259}
260#else
261#define jffs2_verify_write(c,b,o) (0)
262#endif
263
223/* Recover from failure to write wbuf. Recover the nodes up to the 264/* Recover from failure to write wbuf. Recover the nodes up to the
224 * wbuf, not the one which we were starting to try to write. */ 265 * wbuf, not the one which we were starting to try to write. */
225 266
@@ -380,7 +421,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
380 ret = c->mtd->write(c->mtd, ofs, towrite, &retlen, 421 ret = c->mtd->write(c->mtd, ofs, towrite, &retlen,
381 rewrite_buf); 422 rewrite_buf);
382 423
383 if (ret || retlen != towrite) { 424 if (ret || retlen != towrite || jffs2_verify_write(c, rewrite_buf, ofs)) {
384 /* Argh. We tried. Really we did. */ 425 /* Argh. We tried. Really we did. */
385 printk(KERN_CRIT "Recovery of wbuf failed due to a second write error\n"); 426 printk(KERN_CRIT "Recovery of wbuf failed due to a second write error\n");
386 kfree(buf); 427 kfree(buf);
@@ -587,15 +628,16 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
587 628
588 ret = c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen, c->wbuf); 629 ret = c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen, c->wbuf);
589 630
590 if (ret || retlen != c->wbuf_pagesize) { 631 if (ret) {
591 if (ret) 632 printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n", ret);
592 printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n",ret); 633 goto wfail;
593 else { 634 } else if (retlen != c->wbuf_pagesize) {
594 printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n", 635 printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n",
595 retlen, c->wbuf_pagesize); 636 retlen, c->wbuf_pagesize);
596 ret = -EIO; 637 ret = -EIO;
597 } 638 goto wfail;
598 639 } else if ((ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs))) {
640 wfail:
599 jffs2_wbuf_recover(c); 641 jffs2_wbuf_recover(c);
600 642
601 return ret; 643 return ret;
@@ -1138,11 +1180,22 @@ int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
1138 return -ENOMEM; 1180 return -ENOMEM;
1139 } 1181 }
1140 1182
1183#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
1184 c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
1185 if (!c->wbuf_verify) {
1186 kfree(c->oobbuf);
1187 kfree(c->wbuf);
1188 return -ENOMEM;
1189 }
1190#endif
1141 return 0; 1191 return 0;
1142} 1192}
1143 1193
1144void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c) 1194void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c)
1145{ 1195{
1196#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
1197 kfree(c->wbuf_verify);
1198#endif
1146 kfree(c->wbuf); 1199 kfree(c->wbuf);
1147 kfree(c->oobbuf); 1200 kfree(c->oobbuf);
1148} 1201}