[Ocfs2-tools-devel] [PATCH] Check dx_tree corruptions

[Goldwyn Rodrigues]

In case of corruption in the dx_tree where the dx_leaf pointer
is not pointing to the correct block, the filesystem turns read-only
upon directory access.
This goes undetected when a fsck is performed on the filesystem
because the primary directory setup is sane.

This patch traverses the dx_tree with a dummy iterator to verify that
the dx_tree is sane and sets the inode for re-indexing, if not.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn at suse.de>

---
diff --git a/fsck.ocfs2/pass2.c b/fsck.ocfs2/pass2.c
index 4b43a22..a1bfdef 100644
--- a/fsck.ocfs2/pass2.c
+++ b/fsck.ocfs2/pass2.c
@@ -698,6 +698,15 @@ static int corrupt_dirent_lengths(struct
ocfs2_dir_entry *dirent, int left)
 	return 1;
 }

+static int dummy_dx_iterator(ocfs2_filesys *fs,
+		struct ocfs2_dx_entry_list *entry_list,
+		struct ocfs2_dx_root_block *dx_root,
+		struct ocfs2_dx_leaf *dx_leaf,
+		void *priv_data)
+{
+	return 0;
+}
+
 /* this could certainly be more clever to issue reads in groups */
 static unsigned pass2_dir_block_iterate(o2fsck_dirblock_entry *dbe,
 					void *priv_data)
@@ -732,6 +741,30 @@ static unsigned
pass2_dir_block_iterate(o2fsck_dirblock_entry *dbe,
 		verbosef("dir inode %"PRIu64" i_size %"PRIu64"\n",
 			 dbe->e_ino, (uint64_t)di->i_size);

+		if ((ocfs2_supports_indexed_dirs(OCFS2_RAW_SB(
+			dd->fs->fs_super))) &&
+				di->i_dyn_features & OCFS2_INDEXED_DIR_FL ) {
+			ret = ocfs2_dx_entries_iterate(dd->fs, di,
+					0, dummy_dx_iterator, NULL);
+			if (ret) {
+				if (prompt(dd->ost, PY, PR_IV_DX_TREE,
+					"Directory inode %"PRIu64" "
+					"has corrupted index tree. "
+					"Rebuild index tree?", dbe->e_ino)) {
+
+					ret = o2fsck_try_add_reidx_dir(
+						&dd->re_idx_dirs, dbe->e_ino);
+					if (ret) {
+					  com_err(whoami, ret, "while adding"
+					    " block for directory inode %"
+					    PRIu64" to rebuild "
+					    "dir index", dbe->e_ino);
+					  goto out;
+					}
+				}
+			}
+		}
+
 	}

 	verbosef("dir block %"PRIu64" block offs %"PRIu64" in ino\n",

-- 
Goldwyn