---

yaml
---
r: 309934
b: refs/heads/master
c: a9c4731
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0441984a3398970ab4820410b9cf4ff85bf3a6b0
+refs/heads/master: a9c4731780544d52b243bf46e4dd635c67fa9f84

trunk/fs/ext4/ext4.h

@@ -1280,6 +1280,9 @@ struct ext4_sb_info {
 
 	/* Reference to checksum algorithm driver via cryptoapi */
 	struct crypto_shash *s_chksum_driver;
+
+	/* Precomputed FS UUID checksum for seeding other checksums */
+	__u32 s_csum_seed;
 };
 
 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -2004,6 +2007,10 @@ extern int ext4_group_extend(struct super_block *sb,
 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
 
 /* super.c */
+extern int ext4_superblock_csum_verify(struct super_block *sb,
+				       struct ext4_super_block *es);
+extern void ext4_superblock_csum_set(struct super_block *sb,
+				     struct ext4_super_block *es);
 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
 extern void ext4_kvfree(void *ptr);
@@ -2279,6 +2286,9 @@ static inline void ext4_unlock_group(struct super_block *sb,
 
 static inline void ext4_mark_super_dirty(struct super_block *sb)
 {
+	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+	ext4_superblock_csum_set(sb, es);
 	if (EXT4_SB(sb)->s_journal == NULL)
 		sb->s_dirt =1;
 }

trunk/fs/ext4/ext4_jbd2.c

@@ -138,16 +138,23 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 }
 
 int __ext4_handle_dirty_super(const char *where, unsigned int line,
-			      handle_t *handle, struct super_block *sb)
+			      handle_t *handle, struct super_block *sb,
+			      int now)
 {
 	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 	int err = 0;
 
 	if (ext4_handle_valid(handle)) {
+		ext4_superblock_csum_set(sb,
+				(struct ext4_super_block *)bh->b_data);
 		err = jbd2_journal_dirty_metadata(handle, bh);
 		if (err)
 			ext4_journal_abort_handle(where, line, __func__,
 						  bh, handle, err);
+	} else if (now) {
+		ext4_superblock_csum_set(sb,
+				(struct ext4_super_block *)bh->b_data);
+		mark_buffer_dirty(bh);
 	} else
 		sb->s_dirt = 1;
 	return err;

trunk/fs/ext4/ext4_jbd2.h

@@ -213,7 +213,8 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 				 struct buffer_head *bh);
 
 int __ext4_handle_dirty_super(const char *where, unsigned int line,
-			      handle_t *handle, struct super_block *sb);
+			      handle_t *handle, struct super_block *sb,
+			      int now);
 
 #define ext4_journal_get_write_access(handle, bh) \
 	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
@@ -225,8 +226,10 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line,
 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 				     (bh))
+#define ext4_handle_dirty_super_now(handle, sb) \
+	__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 1)
 #define ext4_handle_dirty_super(handle, sb) \
-	__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
+	__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 0)
 
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);

trunk/fs/ext4/inode.c

@@ -3936,7 +3936,7 @@ static int ext4_do_update_inode(handle_t *handle,
 			EXT4_SET_RO_COMPAT_FEATURE(sb,
 					EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
 			ext4_handle_sync(handle);
-			err = ext4_handle_dirty_super(handle, sb);
+			err = ext4_handle_dirty_super_now(handle, sb);
 		}
 	}
 	raw_inode->i_generation = cpu_to_le32(inode->i_generation);

trunk/fs/ext4/namei.c

@@ -2021,7 +2021,7 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	/* Insert this inode at the head of the on-disk orphan list... */
 	NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
 	EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
-	err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+	err = ext4_handle_dirty_super_now(handle, sb);
 	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
 	if (!err)
 		err = rc;
@@ -2094,7 +2094,7 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 		if (err)
 			goto out_brelse;
 		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
-		err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
+		err = ext4_handle_dirty_super_now(handle, inode->i_sb);
 	} else {
 		struct ext4_iloc iloc2;
 		struct inode *i_prev =

trunk/fs/ext4/resize.c

@@ -796,7 +796,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 	ext4_kvfree(o_group_desc);
 
 	le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
-	err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+	err = ext4_handle_dirty_super_now(handle, sb);
 	if (err)
 		ext4_std_error(sb, err);
 
@@ -968,6 +968,8 @@ static void update_backups(struct super_block *sb,
 		goto exit_err;
 	}
 
+	ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
+
 	while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
 		struct buffer_head *bh;
 

trunk/fs/ext4/super.c

@@ -122,6 +122,38 @@ static int ext4_verify_csum_type(struct super_block *sb,
 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 }
 
+static __le32 ext4_superblock_csum(struct super_block *sb,
+				   struct ext4_super_block *es)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int offset = offsetof(struct ext4_super_block, s_checksum);
+	__u32 csum;
+
+	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
+
+	return cpu_to_le32(csum);
+}
+
+int ext4_superblock_csum_verify(struct super_block *sb,
+				struct ext4_super_block *es)
+{
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	return es->s_checksum == ext4_superblock_csum(sb, es);
+}
+
+void ext4_superblock_csum_set(struct super_block *sb,
+			      struct ext4_super_block *es)
+{
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	es->s_checksum = ext4_superblock_csum(sb, es);
+}
+
 void *ext4_kvmalloc(size_t size, gfp_t flags)
 {
 	void *ret;
@@ -3057,6 +3089,20 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		}
 	}
 
+	/* Check superblock checksum */
+	if (!ext4_superblock_csum_verify(sb, es)) {
+		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
+			 "invalid superblock checksum.  Run e2fsck?");
+		silent = 1;
+		goto cantfind_ext4;
+	}
+
+	/* Precompute checksum seed for all metadata */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
+					       sizeof(es->s_uuid));
+
 	/* Set defaults before we parse the mount options */
 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 	set_opt(sb, INIT_INODE_TABLE);
@@ -4059,6 +4105,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
 				&EXT4_SB(sb)->s_freeinodes_counter));
 	sb->s_dirt = 0;
 	BUFFER_TRACE(sbh, "marking dirty");
+	ext4_superblock_csum_set(sb, es);
 	mark_buffer_dirty(sbh);
 	if (sync) {
 		error = sync_dirty_buffer(sbh);