[PATCH RFC 13/17] ubifs: repair: Build LPT

[Zhihao Cheng]

This is the 11/13 step of repairing. All LEBs' properties can be
calculated in previous steps according to all nodes' position, then
construct LPT just like mkfs does, and write TNC on flash.

Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
 fs/ubifs/repair.c | 113 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 93 insertions(+), 20 deletions(-)

diff --git a/fs/ubifs/repair.c b/fs/ubifs/repair.c
index 724f58510599..8d40cff26f7a 100644
--- a/fs/ubifs/repair.c
+++ b/fs/ubifs/repair.c
@@ -1059,6 +1059,21 @@ lookup_valid_dent_node(struct ubifs_info *c, struct scanned_info *si,
 	return NULL;
 }
 
+static void update_lpt(struct ubifs_info *c, struct scanned_node *sn,
+		       bool deleted)
+{
+	int lnum = sn->lnum - c->main_first;
+	int pos = sn->offs + ALIGN(sn->len, 8);
+
+	set_bit(lnum, c->repair->used_lebs);
+	c->repair->lpts[lnum].end = max(c->repair->lpts[lnum].end, pos);
+
+	if (deleted)
+		return;
+
+	c->repair->lpts[lnum].used += ALIGN(sn->len, 8);
+}
+
 /**
  * remove_del_nodes - remove deleted nodes from valid node tree.
  * @c: UBIFS file-system description object
@@ -1083,13 +1098,7 @@ static void remove_del_nodes(struct ubifs_info *c, struct scanned_info *si)
 
 		valid_ino_node = lookup_valid_ino_node(c, si, del_ino_node);
 		if (valid_ino_node) {
-			int lnum = del_ino_node->header.lnum - c->main_first;
-			int pos = del_ino_node->header.offs +
-				  ALIGN(del_ino_node->header.len, 8);
-
-			set_bit(lnum, c->repair->used_lebs);
-			c->repair->lpts[lnum].end =
-					max(c->repair->lpts[lnum].end, pos);
+			update_lpt(c, &del_ino_node->header, true);
 			rb_erase(&valid_ino_node->rb, &si->valid_inos);
 			kfree(valid_ino_node);
 		}
@@ -1106,13 +1115,7 @@ static void remove_del_nodes(struct ubifs_info *c, struct scanned_info *si)
 
 		valid_dent_node = lookup_valid_dent_node(c, si, del_dent_node);
 		if (valid_dent_node) {
-			int lnum = del_dent_node->header.lnum - c->main_first;
-			int pos = del_dent_node->header.offs +
-				  ALIGN(del_dent_node->header.len, 8);
-
-			set_bit(lnum, c->repair->used_lebs);
-			c->repair->lpts[lnum].end =
-					max(c->repair->lpts[lnum].end, pos);
+			update_lpt(c, &del_dent_node->header, true);
 			rb_erase(&valid_dent_node->rb, &si->valid_dents);
 			kfree(valid_dent_node);
 		}
@@ -1861,6 +1864,14 @@ static int flush_write_buf(struct ubifs_info *c)
 	if (err)
 		return err;
 
+	if (c->repair->need_update_lpt) {
+		int lnum = c->repair->head_lnum - c->main_first;
+
+		c->repair->lpts[lnum].free = c->leb_size - len;
+		c->repair->lpts[lnum].dirty = pad;
+		c->repair->lpts[lnum].flags = LPROPS_INDEX;
+	}
+
 	c->repair->head_lnum = -1;
 
 	return 0;
@@ -2001,14 +2012,9 @@ static int parse_node_info(struct ubifs_info *c, struct scanned_node *sn,
 			   union ubifs_key *key, char *name, int name_len,
 			   struct list_head *idx_list, int *idx_cnt)
 {
-	int lnum, pos;
 	struct idx_entry *e;
 
-	lnum = sn->lnum - c->main_first;
-	pos = sn->offs + ALIGN(sn->len, 8);
-
-	set_bit(lnum, c->repair->used_lebs);
-	c->repair->lpts[lnum].end = max(c->repair->lpts[lnum].end, pos);
+	update_lpt(c, sn, idx_cnt == NULL);
 
 	if (idx_cnt == NULL)
 		/* Skip truncation node. */
@@ -2085,6 +2091,7 @@ static int build_tnc(struct ubifs_info *c, struct list_head *lower_idxs,
 		return -ENOMEM;
 
 	list_sort(c, lower_idxs, cmp_idx);
+	c->repair->need_update_lpt = true;
 
 	ubifs_assert(c, lower_cnt != 0);
 
@@ -2156,6 +2163,7 @@ static int build_tnc(struct ubifs_info *c, struct list_head *lower_idxs,
 
 	/* Flush the last index LEB */
 	err = flush_write_buf(c);
+	c->repair->need_update_lpt = false;
 
 out:
 	list_for_each_entry_safe(e, tmp_e, lower_idxs, list) {
@@ -2300,6 +2308,65 @@ static int traverse_files_and_nodes(struct ubifs_info *c)
 	return err;
 }
 
+/**
+ * build_lpt - construct LPT and write it into flash.
+ * @c: UBIFS file-system description object
+ *
+ * This function builds LPT according to @c->repair->lpts and writes LPT
+ * into flash.
+ */
+int build_lpt(struct ubifs_info *c)
+{
+	int i, len, free, dirty, err;
+	u8 hash_lpt[UBIFS_HASH_ARR_SZ];
+
+	/* Set gc lnum. */
+	err = get_free_leb(c);
+	if (err)
+		return err;
+	c->gc_lnum = c->repair->head_lnum;
+	/* GC LEB is empty. */
+	c->lst.empty_lebs = 1;
+
+	/* Update LPT. */
+	for (i = 0; i < c->main_lebs; i++) {
+		cond_resched();
+
+		if (!test_bit(i, c->repair->used_lebs)) {
+			free = c->leb_size;
+			dirty = 0;
+			c->lst.empty_lebs++;
+		} else if (c->repair->lpts[i].flags & LPROPS_INDEX) {
+			free = c->repair->lpts[i].free;
+			dirty = c->repair->lpts[i].dirty;
+			c->lst.idx_lebs += 1;
+		} else {
+			len = ALIGN(c->repair->lpts[i].end, c->min_io_size);
+			free = c->leb_size - len;
+			dirty = len - c->repair->lpts[i].used;
+		}
+
+		c->repair->lpts[i].free = free;
+		c->repair->lpts[i].dirty = dirty;
+		c->lst.total_free += free;
+		c->lst.total_dirty += dirty;
+
+		if (!(c->repair->lpts[i].flags & LPROPS_INDEX)) {
+			int spc;
+
+			spc = free + dirty;
+			if (spc < c->dead_wm)
+				c->lst.total_dead += spc;
+			else
+				c->lst.total_dark += ubifs_calc_dark(c, spc);
+			c->lst.total_used += c->leb_size - spc;
+		}
+	}
+
+	/* Write LPT. */
+	return ubifs_create_lpt(c, c->repair->lpts, c->main_lebs, hash_lpt);
+}
+
 static int do_repair(struct ubifs_info *c)
 {
 	int err = 0;
@@ -2343,6 +2410,12 @@ static int do_repair(struct ubifs_info *c)
 	 * Step 10: Build TNC.
 	 */
 	err = traverse_files_and_nodes(c);
+	if (err)
+		goto out;
+
+	/* Step 11. Build LPT. */
+	ubifs_msg(c, "Step 11: Build LPT");
+	err = build_lpt(c);
 
 out:
 	destroy_scanned_info(c, &si);
-- 
2.31.1