[PATCH 24/54] e2fsck: Verify htree root/node checksums

["Darrick J. Wong" <djwong@us.ibm.com>]

Check htree internal node checksums.  If broken, ask user to clear the htree
index and recreate it later.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
 e2fsck/e2fsck.h  |    2 ++
 e2fsck/pass2.c   |   34 +++++++++++++++++++++++++++++-----
 e2fsck/problem.c |   10 ++++++++++
 e2fsck/problem.h |    6 ++++++
 e2fsck/rehash.c  |   41 +++++++++++++++++++++++++++++++++++++++--
 5 files changed, 86 insertions(+), 7 deletions(-)


diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index ed8b0c7..c6dab54 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -483,6 +483,8 @@ extern void region_free(region_t region);
 extern int region_allocate(region_t region, region_addr_t start, int n);
 
 /* rehash.c */
+void e2fsck_rehash_dir_later(e2fsck_t ctx, ext2_ino_t ino);
+int e2fsck_dir_will_be_rehashed(e2fsck_t ctx, ext2_ino_t ino);
 errcode_t e2fsck_rehash_dir(e2fsck_t ctx, ext2_ino_t ino);
 void e2fsck_rehash_directories(e2fsck_t ctx);
 
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index 882950d..e4a06f3 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c
@@ -527,7 +527,7 @@ static void parse_int_node(ext2_filsys fs,
 			   struct ext2_db_entry2 *db,
 			   struct check_dir_struct *cd,
 			   struct dx_dir_info	*dx_dir,
-			   char *block_buf)
+			   char *block_buf, int failed_csum)
 {
 	struct 		ext2_dx_root_info  *root;
 	struct 		ext2_dx_entry *ent;
@@ -538,6 +538,7 @@ static void parse_int_node(ext2_filsys fs,
 	ext2_dirhash_t	min_hash = 0xffffffff;
 	ext2_dirhash_t	max_hash = 0;
 	ext2_dirhash_t	hash = 0, prev_hash;
+	int		csum_size = 0;
 
 	if (db->blockcnt == 0) {
 		root = (struct ext2_dx_root_info *) (block_buf + 24);
@@ -552,9 +553,22 @@ static void parse_int_node(ext2_filsys fs,
 #endif
 
 		ent = (struct ext2_dx_entry *) (block_buf + 24 + root->info_length);
+
+		if (failed_csum &&
+		    (e2fsck_dir_will_be_rehashed(cd->ctx, cd->pctx.ino) ||
+		     fix_problem(cd->ctx, PR_2_HTREE_ROOT_CSUM_INVALID,
+				&cd->pctx)))
+			goto clear_and_exit;
 	} else {
 		ent = (struct ext2_dx_entry *) (block_buf+8);
+
+		if (failed_csum &&
+		    (e2fsck_dir_will_be_rehashed(cd->ctx, cd->pctx.ino) ||
+		     fix_problem(cd->ctx, PR_2_HTREE_NODE_CSUM_INVALID,
+				&cd->pctx)))
+			goto clear_and_exit;
 	}
+
 	limit = (struct ext2_dx_countlimit *) ent;
 
 #ifdef DX_DEBUG
@@ -565,8 +579,12 @@ static void parse_int_node(ext2_filsys fs,
 #endif
 
 	count = ext2fs_le16_to_cpu(limit->count);
-	expect_limit = (fs->blocksize - ((char *) ent - block_buf)) /
-		sizeof(struct ext2_dx_entry);
+	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext2_dx_tail);
+	expect_limit = (fs->blocksize -
+			(csum_size + ((char *) ent - block_buf))) /
+		       sizeof(struct ext2_dx_entry);
 	if (ext2fs_le16_to_cpu(limit->limit) != expect_limit) {
 		cd->pctx.num = ext2fs_le16_to_cpu(limit->limit);
 		if (fix_problem(cd->ctx, PR_2_HTREE_BAD_LIMIT, &cd->pctx))
@@ -632,6 +650,7 @@ static void parse_int_node(ext2_filsys fs,
 clear_and_exit:
 	clear_htree(cd->ctx, cd->pctx.ino);
 	dx_dir->numblocks = 0;
+	e2fsck_rehash_dir_later(cd->ctx, cd->pctx.ino);
 }
 #endif /* ENABLE_HTREE */
 
@@ -734,6 +753,7 @@ static int check_dir_block(ext2_filsys fs,
 	struct problem_context	pctx;
 	int	dups_found = 0;
 	int	ret;
+	int	dx_csum_size = 0;
 
 	cd = (struct check_dir_struct *) priv_data;
 	buf = cd->buf;
@@ -745,6 +765,10 @@ static int check_dir_block(ext2_filsys fs,
 	if (ctx->progress && (ctx->progress)(ctx, 2, cd->count++, cd->max))
 		return DIRENT_ABORT;
 
+	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		dx_csum_size = sizeof(struct ext2_dx_tail);
+
 	/*
 	 * Make sure the inode is still in use (could have been
 	 * deleted in the duplicate/bad blocks pass.
@@ -834,7 +858,7 @@ static int check_dir_block(ext2_filsys fs,
 			   (rec_len == fs->blocksize) &&
 			   (dirent->name_len == 0) &&
 			   (ext2fs_le16_to_cpu(limit->limit) ==
-			    ((fs->blocksize-8) /
+			    ((fs->blocksize - (8 + dx_csum_size)) /
 			     sizeof(struct ext2_dx_entry))))
 			dx_db->type = DX_DIRBLOCK_NODE;
 	}
@@ -1121,7 +1145,7 @@ out_htree:
 		cd->pctx.dir = cd->pctx.ino;
 		if ((dx_db->type == DX_DIRBLOCK_ROOT) ||
 		    (dx_db->type == DX_DIRBLOCK_NODE))
-			parse_int_node(fs, db, cd, dx_dir, buf);
+			parse_int_node(fs, db, cd, dx_dir, buf, 0);
 	}
 #endif /* ENABLE_HTREE */
 	if (offset != fs->blocksize) {
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 6ceee11..25db675 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -1383,6 +1383,16 @@ static struct e2fsck_problem problem_table[] = {
 	  N_("i_file_acl_hi @F %N, @s zero.\n"),
 	  PROMPT_CLEAR, PR_PREEN_OK },
 
+	/* htree root node fails checksum */
+	{ PR_2_HTREE_ROOT_CSUM_INVALID,
+	  N_("@p @h %d: root node fails checksum\n"),
+	  PROMPT_CLEAR_HTREE, PR_PREEN_OK },
+
+	/* htree internal node fails checksum */
+	{ PR_2_HTREE_NODE_CSUM_INVALID,
+	  N_("@p @h %d: internal node fails checksum\n"),
+	  PROMPT_CLEAR_HTREE, PR_PREEN_OK },
+
 	/* Pass 3 errors */
 
 	/* Pass 3: Checking directory connectivity */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index 2adb4b9..5cf80fb 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -827,6 +827,12 @@ struct problem_context {
 /* i_file_acl_hi should be zero */
 #define PR_2_I_FILE_ACL_HI_ZERO		0x020048
 
+/* htree root node fails checksum */
+#define PR_2_HTREE_ROOT_CSUM_INVALID	0x020049
+
+/* htree node fails checksum */
+#define PR_2_HTREE_NODE_CSUM_INVALID	0x02004A
+
 /*
  * Pass 3 errors
  */
diff --git a/e2fsck/rehash.c b/e2fsck/rehash.c
index 15993b3..610b3bf 100644
--- a/e2fsck/rehash.c
+++ b/e2fsck/rehash.c
@@ -52,6 +52,25 @@
 #include "e2fsck.h"
 #include "problem.h"
 
+/* Schedule a dir to be rebuilt during pass 3A. */
+void e2fsck_rehash_dir_later(e2fsck_t ctx, ext2_ino_t ino)
+{
+	if (!ctx->dirs_to_hash)
+		ext2fs_u32_list_create(&ctx->dirs_to_hash, 50);
+	if (ctx->dirs_to_hash)
+		ext2fs_u32_list_add(ctx->dirs_to_hash, ino);
+}
+
+/* Ask if a dir will be rebuilt during pass 3A. */
+int e2fsck_dir_will_be_rehashed(e2fsck_t ctx, ext2_ino_t ino)
+{
+	if (ctx->options & E2F_OPT_COMPRESS_DIRS)
+		return 1;
+	if (!ctx->dirs_to_hash)
+		return 0;
+	return ext2fs_u32_list_test(ctx->dirs_to_hash, ino);
+}
+
 struct fill_dir_struct {
 	char *buf;
 	struct ext2_inode *inode;
@@ -495,6 +514,7 @@ static struct ext2_dx_root_info *set_root_node(ext2_filsys fs, char *buf,
 	struct ext2_dx_root_info  	*root;
 	struct ext2_dx_countlimit	*limits;
 	int				filetype = 0;
+	int				csum_size = 0;
 
 	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE)
 		filetype = EXT2_FT_DIR << 8;
@@ -519,8 +539,13 @@ static struct ext2_dx_root_info *set_root_node(ext2_filsys fs, char *buf,
 	root->indirect_levels = 0;
 	root->unused_flags = 0;
 
+	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext2_dx_tail);
+
 	limits = (struct ext2_dx_countlimit *) (buf+32);
-	limits->limit = (fs->blocksize - 32) / sizeof(struct ext2_dx_entry);
+	limits->limit = (fs->blocksize - (32 + csum_size)) /
+			sizeof(struct ext2_dx_entry);
 	limits->count = 0;
 
 	return root;
@@ -531,14 +556,20 @@ static struct ext2_dx_entry *set_int_node(ext2_filsys fs, char *buf)
 {
 	struct ext2_dir_entry 		*dir;
 	struct ext2_dx_countlimit	*limits;
+	int				csum_size = 0;
 
 	memset(buf, 0, fs->blocksize);
 	dir = (struct ext2_dir_entry *) buf;
 	dir->inode = 0;
 	(void) ext2fs_set_rec_len(fs, fs->blocksize, dir);
 
+	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext2_dx_tail);
+
 	limits = (struct ext2_dx_countlimit *) (buf+8);
-	limits->limit = (fs->blocksize - 8) / sizeof(struct ext2_dx_entry);
+	limits->limit = (fs->blocksize - (8 + csum_size)) /
+			sizeof(struct ext2_dx_entry);
 	limits->count = 0;
 
 	return (struct ext2_dx_entry *) limits;
@@ -865,8 +896,14 @@ void e2fsck_rehash_directories(e2fsck_t ctx)
 			if (!ext2fs_u32_list_iterate(iter, &ino))
 				break;
 		}
+#if 0
+		/*
+		 * lost+found must not be excluded from cleanups or else
+		 * checksum errors won't get fixed.
+		 */
 		if (ino == ctx->lost_and_found)
 			continue;
+#endif
 		pctx.dir = ino;
 		if (first) {
 			fix_problem(ctx, PR_3A_PASS_HEADER, &pctx);