[PATCH 1/3] xfs_repair: Fix fragmented multiblock dir2 handling in blkmap_getn()

[Eric Sandeen]

blkmap_getn() contains a loop which populates an array of extents
with mapping information for a dir2 "block," which may consist
of multiple filesystem blocks.

As written, the loop re-allocates the array for each new extent,
leaking the previously allocated memory and worse, losing the
previously filled-in extent information.

Fix this by only allocating the array once, for the maximum
possible number of extents - the number of fs blocks in the dir
block.

Signed-off-by: Eric Sandeen <sandeen at redhat.com>
---

diff --git a/repair/bmap.c b/repair/bmap.c
index 2f1c307..c43ca7f 100644
--- a/repair/bmap.c
+++ b/repair/bmap.c
@@ -168,7 +168,8 @@ blkmap_getn(
 		/*
 		 * rare case - multiple extents for a single dir block
 		 */
-		bmp = malloc(nb * sizeof(bmap_ext_t));
+		if (!bmp)
+			bmp = malloc(nb * sizeof(bmap_ext_t));
 		if (!bmp)
 			do_error(_("blkmap_getn malloc failed (%" PRIu64 " bytes)\n"),
 						nb * sizeof(bmap_ext_t));