+ * Check the data CRC of the node.
+ *
+ * Returns: 0 if the data CRC is correct;
+ * 1 - if incorrect;
+ * error code if an error occured.
+ */
+static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
+{
+ struct jffs2_raw_node_ref *ref = tn->fn->raw;
+ int err = 0, pointed = 0;
+ struct jffs2_eraseblock *jeb;
+ unsigned char *buffer;
+ uint32_t crc, ofs, len;
+ size_t retlen;
+
+ BUG_ON(tn->csize == 0);
+
+ if (!jffs2_is_writebuffered(c))
+ goto adj_acc;
+
+ /* Calculate how many bytes were already checked */
+ ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
+ len = ofs % c->wbuf_pagesize;
+ if (likely(len))
+ len = c->wbuf_pagesize - len;
+
+ if (len >= tn->csize) {
+ dbg_readinode("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
+ ref_offset(ref), tn->csize, ofs);
+ goto adj_acc;
+ }
+
+ ofs += len;
+ len = tn->csize - len;
+
+ dbg_readinode("check node at %#08x, data length %u, partial CRC %#08x, correct CRC %#08x, data starts at %#08x, start checking from %#08x - %u bytes.\n",
+ ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
+
+#ifndef __ECOS
+ /* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
+ * adding and jffs2_flash_read_end() interface. */
+ if (c->mtd->point) {
+ err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
+ if (!err && retlen < tn->csize) {
+ JFFS2_WARNING("MTD point returned len too short: %zu instead of %u.\n", retlen, tn->csize);
+ c->mtd->unpoint(c->mtd, buffer, ofs, retlen);
+ } else if (err)
+ JFFS2_WARNING("MTD point failed: error code %d.\n", err);
+ else
+ pointed = 1; /* succefully pointed to device */
+ }
+#endif
+
+ if (!pointed) {
+ buffer = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!buffer))
+ return -ENOMEM;
+
+ /* TODO: this is very frequent pattern, make it a separate
+ * routine */
+ err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
+ if (err) {
+ JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
+ goto free_out;
+ }
+
+ if (retlen != len) {
+ JFFS2_ERROR("short read at %#08x: %zd instead of %d.\n", ofs, retlen, len);
+ err = -EIO;
+ goto free_out;
+ }
+ }
+
+ /* Continue calculating CRC */
+ crc = crc32(tn->partial_crc, buffer, len);
+ if(!pointed)
+ kfree(buffer);
+#ifndef __ECOS
+ else
+ c->mtd->unpoint(c->mtd, buffer, ofs, len);
+#endif
+
+ if (crc != tn->data_crc) {
+ JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
+ ref_offset(ref), tn->data_crc, crc);
+ return 1;
+ }
+
+adj_acc:
+ jeb = &c->blocks[ref->flash_offset / c->sector_size];
+ len = ref_totlen(c, jeb, ref);
+ /* If it should be REF_NORMAL, it'll get marked as such when
+ we build the fragtree, shortly. No need to worry about GC
+ moving it while it's marked REF_PRISTINE -- GC won't happen
+ till we've finished checking every inode anyway. */
+ ref->flash_offset |= REF_PRISTINE;
+ /*
+ * Mark the node as having been checked and fix the
+ * accounting accordingly.
+ */
+ spin_lock(&c->erase_completion_lock);
+ jeb->used_size += len;
+ jeb->unchecked_size -= len;
+ c->used_size += len;
+ c->unchecked_size -= len;
+ jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+ spin_unlock(&c->erase_completion_lock);
+
+ return 0;
+
+free_out:
+ if(!pointed)
+ kfree(buffer);
+#ifndef __ECOS
+ else
+ c->mtd->unpoint(c->mtd, buffer, ofs, len);
+#endif
+ return err;
+}
+
+/*
+ * Helper function for jffs2_add_older_frag_to_fragtree().
+ *
+ * Checks the node if we are in the checking stage.
+ */
+static int check_tn_node(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
+{
+ int ret;
+
+ BUG_ON(ref_obsolete(tn->fn->raw));
+
+ /* We only check the data CRC of unchecked nodes */
+ if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
+ return 0;
+
+ dbg_readinode("check node %#04x-%#04x, phys offs %#08x\n",
+ tn->fn->ofs, tn->fn->ofs + tn->fn->size, ref_offset(tn->fn->raw));
+
+ ret = check_node_data(c, tn);
+ if (unlikely(ret < 0)) {
+ JFFS2_ERROR("check_node_data() returned error: %d.\n",
+ ret);
+ } else if (unlikely(ret > 0)) {
+ dbg_readinode("CRC error, mark it obsolete.\n");
+ jffs2_mark_node_obsolete(c, tn->fn->raw);
+ }
+
+ return ret;
+}
+
+static struct jffs2_tmp_dnode_info *jffs2_lookup_tn(struct rb_root *tn_root, uint32_t offset)
+{
+ struct rb_node *next;
+ struct jffs2_tmp_dnode_info *tn = NULL;
+
+ dbg_readinode("root %p, offset %d\n", tn_root, offset);
+
+ next = tn_root->rb_node;
+
+ while (next) {
+ tn = rb_entry(next, struct jffs2_tmp_dnode_info, rb);
+
+ if (tn->fn->ofs < offset)
+ next = tn->rb.rb_right;
+ else if (tn->fn->ofs >= offset)
+ next = tn->rb.rb_left;
+ else
+ break;
+ }
+
+ return tn;
+}
+
+
+static void jffs2_kill_tn(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
+{
+ jffs2_mark_node_obsolete(c, tn->fn->raw);
+ jffs2_free_full_dnode(tn->fn);
+ jffs2_free_tmp_dnode_info(tn);
+}
+/*
+ * This function is used when we read an inode. Data nodes arrive in
+ * arbitrary order -- they may be older or newer than the nodes which
+ * are already in the tree. Where overlaps occur, the older node can
+ * be discarded as long as the newer passes the CRC check. We don't
+ * bother to keep track of holes in this rbtree, and neither do we deal
+ * with frags -- we can have multiple entries starting at the same
+ * offset, and the one with the smallest length will come first in the
+ * ordering.
+ *
+ * Returns 0 if the node was handled (including marking it obsolete)
+ * < 0 an if error occurred