Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull Ext4 updates from Theodore Ts'o:
 "The major new feature added in this update is Darrick J Wong's
  metadata checksum feature, which adds crc32 checksums to ext4's
  metadata fields.

  There is also the usual set of cleanups and bug fixes."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (44 commits)
  ext4: hole-punch use truncate_pagecache_range
  jbd2: use kmem_cache_zalloc wrapper instead of flag
  ext4: remove mb_groups before tearing down the buddy_cache
  ext4: add ext4_mb_unload_buddy in the error path
  ext4: don't trash state flags in EXT4_IOC_SETFLAGS
  ext4: let getattr report the right blocks in delalloc+bigalloc
  ext4: add missing save_error_info() to ext4_error()
  ext4: add debugging trigger for ext4_error()
  ext4: protect group inode free counting with group lock
  ext4: use consistent ssize_t type in ext4_file_write()
  ext4: fix format flag in ext4_ext_binsearch_idx()
  ext4: cleanup in ext4_discard_allocated_blocks()
  ext4: return ENOMEM when mounts fail due to lack of memory
  ext4: remove redundundant "(char *) bh->b_data" casts
  ext4: disallow hard-linked directory in ext4_lookup
  ext4: fix potential integer overflow in alloc_flex_gd()
  ext4: remove needs_recovery in ext4_mb_init()
  ext4: force ro mount if ext4_setup_super() fails
  ext4: fix potential NULL dereference in ext4_free_inodes_counts()
  ext4/jbd2: add metadata checksumming to the list of supported features
  ...

fs/ext4/Kconfig

@@ -2,6 +2,8 @@ config EXT4_FS
 	tristate "The Extended 4 (ext4) filesystem"
 	select JBD2
 	select CRC16
+	select CRYPTO
+	select CRYPTO_CRC32C
 	help
 	  This is the next generation of the ext3 filesystem.
 

fs/ext4/balloc.c

@@ -168,12 +168,14 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 
 	/* If checksum is bad mark all blocks used to prevent allocation
 	 * essentially implementing a per-group read-only flag. */
-	if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
+	if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
 		ext4_error(sb, "Checksum bad for group %u", block_group);
 		ext4_free_group_clusters_set(sb, gdp, 0);
 		ext4_free_inodes_set(sb, gdp, 0);
 		ext4_itable_unused_set(sb, gdp, 0);
 		memset(bh->b_data, 0xff, sb->s_blocksize);
+		ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
+					   EXT4_BLOCKS_PER_GROUP(sb) / 8);
 		return;
 	}
 	memset(bh->b_data, 0, sb->s_blocksize);
@@ -210,6 +212,9 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 	 */
 	ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
 			     sb->s_blocksize * 8, bh->b_data);
+	ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
+				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
 }
 
 /* Return the number of free blocks in a block group.  It is used when
@@ -276,9 +281,9 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
 }
 
 static int ext4_valid_block_bitmap(struct super_block *sb,
-					struct ext4_group_desc *desc,
-					unsigned int block_group,
-					struct buffer_head *bh)
+				   struct ext4_group_desc *desc,
+				   unsigned int block_group,
+				   struct buffer_head *bh)
 {
 	ext4_grpblk_t offset;
 	ext4_grpblk_t next_zero_bit;
@@ -325,6 +330,23 @@ err_out:
 			block_group, bitmap_blk);
 	return 0;
 }
+
+void ext4_validate_block_bitmap(struct super_block *sb,
+			       struct ext4_group_desc *desc,
+			       unsigned int block_group,
+			       struct buffer_head *bh)
+{
+	if (buffer_verified(bh))
+		return;
+
+	ext4_lock_group(sb, block_group);
+	if (ext4_valid_block_bitmap(sb, desc, block_group, bh) &&
+	    ext4_block_bitmap_csum_verify(sb, block_group, desc, bh,
+					  EXT4_BLOCKS_PER_GROUP(sb) / 8))
+		set_buffer_verified(bh);
+	ext4_unlock_group(sb, block_group);
+}
+
 /**
  * ext4_read_block_bitmap()
  * @sb:			super block
@@ -355,12 +377,12 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
 	}
 
 	if (bitmap_uptodate(bh))
-		return bh;
+		goto verify;
 
 	lock_buffer(bh);
 	if (bitmap_uptodate(bh)) {
 		unlock_buffer(bh);
-		return bh;
+		goto verify;
 	}
 	ext4_lock_group(sb, block_group);
 	if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
@@ -379,7 +401,7 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
 		 */
 		set_bitmap_uptodate(bh);
 		unlock_buffer(bh);
-		return bh;
+		goto verify;
 	}
 	/*
 	 * submit the buffer_head for reading
@@ -390,6 +412,9 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
 	get_bh(bh);
 	submit_bh(READ, bh);
 	return bh;
+verify:
+	ext4_validate_block_bitmap(sb, desc, block_group, bh);
+	return bh;
 }
 
 /* Returns 0 on success, 1 on error */
@@ -412,7 +437,7 @@ int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group,
 	}
 	clear_buffer_new(bh);
 	/* Panic or remount fs read-only if block bitmap is invalid */
-	ext4_valid_block_bitmap(sb, desc, block_group, bh);
+	ext4_validate_block_bitmap(sb, desc, block_group, bh);
 	return 0;
 }
 

fs/ext4/bitmap.c

@@ -29,3 +29,86 @@ unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars)
 
 #endif  /*  EXT4FS_DEBUG  */
 
+int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+				  struct ext4_group_desc *gdp,
+				  struct buffer_head *bh, int sz)
+{
+	__u32 hi;
+	__u32 provided, calculated;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
+	calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+	if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
+		hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
+		provided |= (hi << 16);
+	} else
+		calculated &= 0xFFFF;
+
+	return provided == calculated;
+}
+
+void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+				struct ext4_group_desc *gdp,
+				struct buffer_head *bh, int sz)
+{
+	__u32 csum;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+	gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+	if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
+		gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}
+
+int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+				  struct ext4_group_desc *gdp,
+				  struct buffer_head *bh, int sz)
+{
+	__u32 hi;
+	__u32 provided, calculated;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
+	calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+	if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
+		hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
+		provided |= (hi << 16);
+	} else
+		calculated &= 0xFFFF;
+
+	if (provided == calculated)
+		return 1;
+
+	ext4_error(sb, "Bad block bitmap checksum: block_group = %u", group);
+	return 0;
+}
+
+void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+				struct ext4_group_desc *gdp,
+				struct buffer_head *bh, int sz)
+{
+	__u32 csum;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+	gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+	if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
+		gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}

fs/ext4/dir.c

@@ -179,6 +179,18 @@ static int ext4_readdir(struct file *filp,
 			continue;
 		}
 
+		/* Check the checksum */
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(inode,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_FILE(filp, 0, "directory fails checksum "
+					"at offset %llu",
+					(unsigned long long)filp->f_pos);
+			filp->f_pos += sb->s_blocksize - offset;
+			continue;
+		}
+		set_buffer_verified(bh);
+
 revalidate:
 		/* If the dir block has changed since the last call to
 		 * readdir(2), then we might be pointing to an invalid

fs/ext4/ext4.h

@@ -29,6 +29,7 @@
 #include <linux/wait.h>
 #include <linux/blockgroup_lock.h>
 #include <linux/percpu_counter.h>
+#include <crypto/hash.h>
 #ifdef __KERNEL__
 #include <linux/compat.h>
 #endif
@@ -298,7 +299,9 @@ struct ext4_group_desc
 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
 	__le16	bg_used_dirs_count_lo;	/* Directories count */
 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
-	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
+	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
+	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
+	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
@@ -308,9 +311,19 @@ struct ext4_group_desc
 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
-	__u32	bg_reserved2[3];
+	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
+	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
+	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
+	__u32   bg_reserved;
 };
 
+#define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
+	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
+	 sizeof(__le16))
+#define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
+	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
+	 sizeof(__le16))
+
 /*
  * Structure of a flex block group info
  */
@@ -650,7 +663,8 @@ struct ext4_inode {
 			__le16	l_i_file_acl_high;
 			__le16	l_i_uid_high;	/* these 2 fields */
 			__le16	l_i_gid_high;	/* were reserved2[0] */
-			__u32	l_i_reserved2;
+			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
+			__le16	l_i_reserved;
 		} linux2;
 		struct {
 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
@@ -666,7 +680,7 @@ struct ext4_inode {
 		} masix2;
 	} osd2;				/* OS dependent 2 */
 	__le16	i_extra_isize;
-	__le16	i_pad1;
+	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
@@ -768,7 +782,7 @@ do {									       \
 #define i_gid_low	i_gid
 #define i_uid_high	osd2.linux2.l_i_uid_high
 #define i_gid_high	osd2.linux2.l_i_gid_high
-#define i_reserved2	osd2.linux2.l_i_reserved2
+#define i_checksum_lo	osd2.linux2.l_i_checksum_lo
 
 #elif defined(__GNU__)
 
@@ -908,6 +922,9 @@ struct ext4_inode_info {
 	 */
 	tid_t i_sync_tid;
 	tid_t i_datasync_tid;
+
+	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
+	__u32 i_csum_seed;
 };
 
 /*
@@ -1001,6 +1018,9 @@ extern void ext4_set_bits(void *bm, int cur, int len);
 #define EXT4_ERRORS_PANIC		3	/* Panic */
 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
 
+/* Metadata checksum algorithm codes */
+#define EXT4_CRC32C_CHKSUM		1
+
 /*
  * Structure of the super block
  */
@@ -1087,7 +1107,7 @@ struct ext4_super_block {
 	__le64  s_mmp_block;            /* Block for multi-mount protection */
 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
-	__u8	s_reserved_char_pad;
+	__u8	s_checksum_type;	/* metadata checksum algorithm used */
 	__le16  s_reserved_pad;
 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
@@ -1113,7 +1133,8 @@ struct ext4_super_block {
 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
-	__le32  s_reserved[109];        /* Padding to the end of the block */
+	__le32	s_reserved[108];	/* Padding to the end of the block */
+	__le32	s_checksum;		/* crc32c(superblock) */
 };
 
 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
@@ -1176,6 +1197,7 @@ struct ext4_sb_info {
 	struct proc_dir_entry *s_proc;
 	struct kobject s_kobj;
 	struct completion s_kobj_unregister;
+	struct super_block *s_sb;
 
 	/* Journaling */
 	struct journal_s *s_journal;
@@ -1266,6 +1288,12 @@ struct ext4_sb_info {
 
 	/* record the last minlen when FITRIM is called. */
 	atomic_t s_last_trim_minblks;
+
+	/* 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)
@@ -1414,6 +1442,12 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
+/*
+ * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
+ * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
+ * all other data structures' checksums.  However, the METADATA_CSUM and
+ * GDT_CSUM bits are mutually exclusive.
+ */
 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
 
 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
@@ -1461,7 +1495,8 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
-					 EXT4_FEATURE_RO_COMPAT_BIGALLOC)
+					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
+					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
 
 /*
  * Default values for user and/or group using reserved blocks
@@ -1526,6 +1561,18 @@ struct ext4_dir_entry_2 {
 	char	name[EXT4_NAME_LEN];	/* File name */
 };
 
+/*
+ * This is a bogus directory entry at the end of each leaf block that
+ * records checksums.
+ */
+struct ext4_dir_entry_tail {
+	__le32	det_reserved_zero1;	/* Pretend to be unused */
+	__le16	det_rec_len;		/* 12 */
+	__u8	det_reserved_zero2;	/* Zero name length */
+	__u8	det_reserved_ft;	/* 0xDE, fake file type */
+	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
+};
+
 /*
  * Ext4 directory file types.  Only the low 3 bits are used.  The
  * other bits are reserved for now.
@@ -1541,6 +1588,8 @@ struct ext4_dir_entry_2 {
 
 #define EXT4_FT_MAX		8
 
+#define EXT4_FT_DIR_CSUM	0xDE
+
 /*
  * EXT4_DIR_PAD defines the directory entries boundaries
  *
@@ -1609,6 +1658,25 @@ static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
 #define DX_HASH_HALF_MD4_UNSIGNED	4
 #define DX_HASH_TEA_UNSIGNED		5
 
+static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
+			      const void *address, unsigned int length)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(sbi->s_chksum_driver)];
+	} desc;
+	int err;
+
+	desc.shash.tfm = sbi->s_chksum_driver;
+	desc.shash.flags = 0;
+	*(u32 *)desc.ctx = crc;
+
+	err = crypto_shash_update(&desc.shash, address, length);
+	BUG_ON(err);
+
+	return *(u32 *)desc.ctx;
+}
+
 #ifdef __KERNEL__
 
 /* hash info structure used by the directory hash */
@@ -1741,7 +1809,8 @@ struct mmp_struct {
 	__le16	mmp_check_interval;
 
 	__le16	mmp_pad1;
-	__le32	mmp_pad2[227];
+	__le32	mmp_pad2[226];
+	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
 };
 
 /* arguments passed to the mmp thread */
@@ -1784,8 +1853,24 @@ struct mmpd_data {
 
 /* bitmap.c */
 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
+void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+				struct ext4_group_desc *gdp,
+				struct buffer_head *bh, int sz);
+int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+				  struct ext4_group_desc *gdp,
+				  struct buffer_head *bh, int sz);
+void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+				struct ext4_group_desc *gdp,
+				struct buffer_head *bh, int sz);
+int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+				  struct ext4_group_desc *gdp,
+				  struct buffer_head *bh, int sz);
 
 /* balloc.c */
+extern void ext4_validate_block_bitmap(struct super_block *sb,
+				       struct ext4_group_desc *desc,
+				       unsigned int block_group,
+				       struct buffer_head *bh);
 extern unsigned int ext4_block_group(struct super_block *sb,
 			ext4_fsblk_t blocknr);
 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
@@ -1864,7 +1949,7 @@ extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
 /* mballoc.c */
 extern long ext4_mb_stats;
 extern long ext4_mb_max_to_scan;
-extern int ext4_mb_init(struct super_block *, int);
+extern int ext4_mb_init(struct super_block *);
 extern int ext4_mb_release(struct super_block *);
 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
 				struct ext4_allocation_request *, int *);
@@ -1936,6 +2021,8 @@ extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
 extern int ext4_ext_migrate(struct inode *);
 
 /* namei.c */
+extern int ext4_dirent_csum_verify(struct inode *inode,
+				   struct ext4_dir_entry *dirent);
 extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
@@ -1950,6 +2037,10 @@ 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);
@@ -2025,10 +2116,17 @@ extern void ext4_used_dirs_set(struct super_block *sb,
 				struct ext4_group_desc *bg, __u32 count);
 extern void ext4_itable_unused_set(struct super_block *sb,
 				   struct ext4_group_desc *bg, __u32 count);
-extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
-				   struct ext4_group_desc *gdp);
-extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
+extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
 				       struct ext4_group_desc *gdp);
+extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
+				     struct ext4_group_desc *gdp);
+
+static inline int ext4_has_group_desc_csum(struct super_block *sb)
+{
+	return EXT4_HAS_RO_COMPAT_FEATURE(sb,
+					  EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
+					  EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+}
 
 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
 {
@@ -2225,6 +2323,9 @@ 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;
 }
@@ -2314,6 +2415,9 @@ extern int ext4_bio_write_page(struct ext4_io_submit *io,
 
 /* mmp.c */
 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
+extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
+extern int ext4_mmp_csum_verify(struct super_block *sb,
+				struct mmp_struct *mmp);
 
 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
 enum ext4_state_bits {

fs/ext4/ext4_extents.h

@@ -63,8 +63,21 @@
  * ext4_inode has i_block array (60 bytes total).
  * The first 12 bytes store ext4_extent_header;
  * the remainder stores an array of ext4_extent.
+ * For non-inode extent blocks, ext4_extent_tail
+ * follows the array.
  */
 
+/*
+ * This is the extent tail on-disk structure.
+ * All other extent structures are 12 bytes long.  It turns out that
+ * block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
+ * covers all valid ext4 block sizes.  Therefore, this tail structure can be
+ * crammed into the end of the block without having to rebalance the tree.
+ */
+struct ext4_extent_tail {
+	__le32	et_checksum;	/* crc32c(uuid+inum+extent_block) */
+};
+
 /*
  * This is the extent on-disk structure.
  * It's used at the bottom of the tree.
@@ -101,6 +114,17 @@ struct ext4_extent_header {
 
 #define EXT4_EXT_MAGIC		cpu_to_le16(0xf30a)
 
+#define EXT4_EXTENT_TAIL_OFFSET(hdr) \
+	(sizeof(struct ext4_extent_header) + \
+	 (sizeof(struct ext4_extent) * le16_to_cpu((hdr)->eh_max)))
+
+static inline struct ext4_extent_tail *
+find_ext4_extent_tail(struct ext4_extent_header *eh)
+{
+	return (struct ext4_extent_tail *)(((void *)eh) +
+					   EXT4_EXTENT_TAIL_OFFSET(eh));
+}
+
 /*
  * Array of ext4_ext_path contains path to some extent.
  * Creation/lookup routines use it for traversal/splitting/etc.

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;

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);

fs/ext4/extents.c

@@ -52,6 +52,46 @@
 #define EXT4_EXT_MARK_UNINIT1	0x2  /* mark first half uninitialized */
 #define EXT4_EXT_MARK_UNINIT2	0x4  /* mark second half uninitialized */
 
+static __le32 ext4_extent_block_csum(struct inode *inode,
+				     struct ext4_extent_header *eh)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	__u32 csum;
+
+	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
+			   EXT4_EXTENT_TAIL_OFFSET(eh));
+	return cpu_to_le32(csum);
+}
+
+static int ext4_extent_block_csum_verify(struct inode *inode,
+					 struct ext4_extent_header *eh)
+{
+	struct ext4_extent_tail *et;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	et = find_ext4_extent_tail(eh);
+	if (et->et_checksum != ext4_extent_block_csum(inode, eh))
+		return 0;
+	return 1;
+}
+
+static void ext4_extent_block_csum_set(struct inode *inode,
+				       struct ext4_extent_header *eh)
+{
+	struct ext4_extent_tail *et;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	et = find_ext4_extent_tail(eh);
+	et->et_checksum = ext4_extent_block_csum(inode, eh);
+}
+
 static int ext4_split_extent(handle_t *handle,
 				struct inode *inode,
 				struct ext4_ext_path *path,
@@ -117,6 +157,7 @@ static int __ext4_ext_dirty(const char *where, unsigned int line,
 {
 	int err;
 	if (path->p_bh) {
+		ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
 		/* path points to block */
 		err = __ext4_handle_dirty_metadata(where, line, handle,
 						   inode, path->p_bh);
@@ -391,6 +432,12 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 		error_msg = "invalid extent entries";
 		goto corrupted;
 	}
+	/* Verify checksum on non-root extent tree nodes */
+	if (ext_depth(inode) != depth &&
+	    !ext4_extent_block_csum_verify(inode, eh)) {
+		error_msg = "extent tree corrupted";
+		goto corrupted;
+	}
 	return 0;
 
 corrupted:
@@ -412,6 +459,26 @@ int ext4_ext_check_inode(struct inode *inode)
 	return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
 }
 
+static int __ext4_ext_check_block(const char *function, unsigned int line,
+				  struct inode *inode,
+				  struct ext4_extent_header *eh,
+				  int depth,
+				  struct buffer_head *bh)
+{
+	int ret;
+
+	if (buffer_verified(bh))
+		return 0;
+	ret = ext4_ext_check(inode, eh, depth);
+	if (ret)
+		return ret;
+	set_buffer_verified(bh);
+	return ret;
+}
+
+#define ext4_ext_check_block(inode, eh, depth, bh)	\
+	__ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
+
 #ifdef EXT_DEBUG
 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 {
@@ -536,7 +603,7 @@ ext4_ext_binsearch_idx(struct inode *inode,
 	}
 
 	path->p_idx = l - 1;
-	ext_debug("  -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
+	ext_debug("  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 		  ext4_idx_pblock(path->p_idx));
 
 #ifdef CHECK_BINSEARCH
@@ -668,8 +735,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 	i = depth;
 	/* walk through the tree */
 	while (i) {
-		int need_to_validate = 0;
-
 		ext_debug("depth %d: num %d, max %d\n",
 			  ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
 
@@ -688,8 +753,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 				put_bh(bh);
 				goto err;
 			}
-			/* validate the extent entries */
-			need_to_validate = 1;
 		}
 		eh = ext_block_hdr(bh);
 		ppos++;
@@ -703,7 +766,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 		path[ppos].p_hdr = eh;
 		i--;
 
-		if (need_to_validate && ext4_ext_check(inode, eh, i))
+		if (ext4_ext_check_block(inode, eh, i, bh))
 			goto err;
 	}
 
@@ -914,6 +977,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		le16_add_cpu(&neh->eh_entries, m);
 	}
 
+	ext4_extent_block_csum_set(inode, neh);
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
@@ -992,6 +1056,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 				sizeof(struct ext4_extent_idx) * m);
 			le16_add_cpu(&neh->eh_entries, m);
 		}
+		ext4_extent_block_csum_set(inode, neh);
 		set_buffer_uptodate(bh);
 		unlock_buffer(bh);
 
@@ -1089,6 +1154,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	else
 		neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
 	neh->eh_magic = EXT4_EXT_MAGIC;
+	ext4_extent_block_csum_set(inode, neh);
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
@@ -1344,7 +1410,8 @@ got_index:
 			return -EIO;
 		eh = ext_block_hdr(bh);
 		/* subtract from p_depth to get proper eh_depth */
-		if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+		if (ext4_ext_check_block(inode, eh,
+					 path->p_depth - depth, bh)) {
 			put_bh(bh);
 			return -EIO;
 		}
@@ -1357,7 +1424,7 @@ got_index:
 	if (bh == NULL)
 		return -EIO;
 	eh = ext_block_hdr(bh);
-	if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+	if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
 		put_bh(bh);
 		return -EIO;
 	}
@@ -2644,8 +2711,8 @@ cont:
 				err = -EIO;
 				break;
 			}
-			if (ext4_ext_check(inode, ext_block_hdr(bh),
-							depth - i - 1)) {
+			if (ext4_ext_check_block(inode, ext_block_hdr(bh),
+							depth - i - 1, bh)) {
 				err = -EIO;
 				break;
 			}
@@ -4722,8 +4789,8 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
 
 	/* Now release the pages */
 	if (last_page_offset > first_page_offset) {
-		truncate_inode_pages_range(mapping, first_page_offset,
-					   last_page_offset-1);
+		truncate_pagecache_range(inode, first_page_offset,
+					 last_page_offset - 1);
 	}
 
 	/* finish any pending end_io work */

fs/ext4/file.c

@@ -95,7 +95,7 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 	int unaligned_aio = 0;
-	int ret;
+	ssize_t ret;
 
 	/*
 	 * If we have encountered a bitmap-format file, the size limit

fs/ext4/ialloc.c

@@ -70,24 +70,27 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb,
 				       ext4_group_t block_group,
 				       struct ext4_group_desc *gdp)
 {
-	struct ext4_sb_info *sbi = EXT4_SB(sb);
-
 	J_ASSERT_BH(bh, buffer_locked(bh));
 
 	/* If checksum is bad mark all blocks and inodes use to prevent
 	 * allocation, essentially implementing a per-group read-only flag. */
-	if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
+	if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
 		ext4_error(sb, "Checksum bad for group %u", block_group);
 		ext4_free_group_clusters_set(sb, gdp, 0);
 		ext4_free_inodes_set(sb, gdp, 0);
 		ext4_itable_unused_set(sb, gdp, 0);
 		memset(bh->b_data, 0xff, sb->s_blocksize);
+		ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
+					   EXT4_INODES_PER_GROUP(sb) / 8);
 		return 0;
 	}
 
 	memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 	ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
 			bh->b_data);
+	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
+				   EXT4_INODES_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
 
 	return EXT4_INODES_PER_GROUP(sb);
 }
@@ -128,12 +131,12 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 		return NULL;
 	}
 	if (bitmap_uptodate(bh))
-		return bh;
+		goto verify;
 
 	lock_buffer(bh);
 	if (bitmap_uptodate(bh)) {
 		unlock_buffer(bh);
-		return bh;
+		goto verify;
 	}
 
 	ext4_lock_group(sb, block_group);
@@ -141,6 +144,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 		ext4_init_inode_bitmap(sb, bh, block_group, desc);
 		set_bitmap_uptodate(bh);
 		set_buffer_uptodate(bh);
+		set_buffer_verified(bh);
 		ext4_unlock_group(sb, block_group);
 		unlock_buffer(bh);
 		return bh;
@@ -154,7 +158,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 		 */
 		set_bitmap_uptodate(bh);
 		unlock_buffer(bh);
-		return bh;
+		goto verify;
 	}
 	/*
 	 * submit the buffer_head for reading
@@ -171,6 +175,20 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 			   block_group, bitmap_blk);
 		return NULL;
 	}
+
+verify:
+	ext4_lock_group(sb, block_group);
+	if (!buffer_verified(bh) &&
+	    !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
+					   EXT4_INODES_PER_GROUP(sb) / 8)) {
+		ext4_unlock_group(sb, block_group);
+		put_bh(bh);
+		ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
+			   "inode_bitmap = %llu", block_group, bitmap_blk);
+		return NULL;
+	}
+	ext4_unlock_group(sb, block_group);
+	set_buffer_verified(bh);
 	return bh;
 }
 
@@ -276,7 +294,9 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
 		ext4_used_dirs_set(sb, gdp, count);
 		percpu_counter_dec(&sbi->s_dirs_counter);
 	}
-	gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
+				   EXT4_INODES_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
 	ext4_unlock_group(sb, block_group);
 
 	percpu_counter_inc(&sbi->s_freeinodes_counter);
@@ -488,10 +508,12 @@ fallback_retry:
 	for (i = 0; i < ngroups; i++) {
 		grp = (parent_group + i) % ngroups;
 		desc = ext4_get_group_desc(sb, grp, NULL);
-		grp_free = ext4_free_inodes_count(sb, desc);
-		if (desc && grp_free && grp_free >= avefreei) {
-			*group = grp;
-			return 0;
+		if (desc) {
+			grp_free = ext4_free_inodes_count(sb, desc);
+			if (grp_free && grp_free >= avefreei) {
+				*group = grp;
+				return 0;
+			}
 		}
 	}
 
@@ -709,7 +731,7 @@ repeat_in_this_group:
 
 got:
 	/* We may have to initialize the block bitmap if it isn't already */
-	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+	if (ext4_has_group_desc_csum(sb) &&
 	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 		struct buffer_head *block_bitmap_bh;
 
@@ -731,8 +753,11 @@ got:
 			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 			ext4_free_group_clusters_set(sb, gdp,
 				ext4_free_clusters_after_init(sb, group, gdp));
-			gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
-								gdp);
+			ext4_block_bitmap_csum_set(sb, group, gdp,
+						   block_bitmap_bh,
+						   EXT4_BLOCKS_PER_GROUP(sb) /
+						   8);
+			ext4_group_desc_csum_set(sb, group, gdp);
 		}
 		ext4_unlock_group(sb, group);
 
@@ -751,7 +776,7 @@ got:
 		goto fail;
 
 	/* Update the relevant bg descriptor fields */
-	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+	if (ext4_has_group_desc_csum(sb)) {
 		int free;
 		struct ext4_group_info *grp = ext4_get_group_info(sb, group);
 
@@ -772,7 +797,10 @@ got:
 			ext4_itable_unused_set(sb, gdp,
 					(EXT4_INODES_PER_GROUP(sb) - ino));
 		up_read(&grp->alloc_sem);
+	} else {
+		ext4_lock_group(sb, group);
 	}
+
 	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
 	if (S_ISDIR(mode)) {
 		ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
@@ -782,10 +810,12 @@ got:
 			atomic_inc(&sbi->s_flex_groups[f].used_dirs);
 		}
 	}
-	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
-		gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
-		ext4_unlock_group(sb, group);
+	if (ext4_has_group_desc_csum(sb)) {
+		ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
+					   EXT4_INODES_PER_GROUP(sb) / 8);
+		ext4_group_desc_csum_set(sb, group, gdp);
 	}
+	ext4_unlock_group(sb, group);
 
 	BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 	err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
@@ -850,6 +880,19 @@ got:
 	inode->i_generation = sbi->s_next_generation++;
 	spin_unlock(&sbi->s_next_gen_lock);
 
+	/* Precompute checksum seed for inode metadata */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+		__u32 csum;
+		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+		__le32 inum = cpu_to_le32(inode->i_ino);
+		__le32 gen = cpu_to_le32(inode->i_generation);
+		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
+				   sizeof(inum));
+		ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
+					      sizeof(gen));
+	}
+
 	ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
 	ext4_set_inode_state(inode, EXT4_STATE_NEW);
 
@@ -1140,7 +1183,7 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
 skip_zeroout:
 	ext4_lock_group(sb, group);
 	gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
-	gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+	ext4_group_desc_csum_set(sb, group, gdp);
 	ext4_unlock_group(sb, group);
 
 	BUFFER_TRACE(group_desc_bh,

fs/ext4/inode.c

@@ -47,6 +47,73 @@
 
 #define MPAGE_DA_EXTENT_TAIL 0x01
 
+static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
+			      struct ext4_inode_info *ei)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	__u16 csum_lo;
+	__u16 csum_hi = 0;
+	__u32 csum;
+
+	csum_lo = raw->i_checksum_lo;
+	raw->i_checksum_lo = 0;
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
+		csum_hi = raw->i_checksum_hi;
+		raw->i_checksum_hi = 0;
+	}
+
+	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
+			   EXT4_INODE_SIZE(inode->i_sb));
+
+	raw->i_checksum_lo = csum_lo;
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+		raw->i_checksum_hi = csum_hi;
+
+	return csum;
+}
+
+static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
+				  struct ext4_inode_info *ei)
+{
+	__u32 provided, calculated;
+
+	if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+	    cpu_to_le32(EXT4_OS_LINUX) ||
+	    !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	provided = le16_to_cpu(raw->i_checksum_lo);
+	calculated = ext4_inode_csum(inode, raw, ei);
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+		provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
+	else
+		calculated &= 0xFFFF;
+
+	return provided == calculated;
+}
+
+static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
+				struct ext4_inode_info *ei)
+{
+	__u32 csum;
+
+	if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+	    cpu_to_le32(EXT4_OS_LINUX) ||
+	    !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	csum = ext4_inode_csum(inode, raw, ei);
+	raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+		raw->i_checksum_hi = cpu_to_le16(csum >> 16);
+}
+
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
 					      loff_t new_size)
 {
@@ -3517,8 +3584,7 @@ make_io:
 				b = table;
 			end = b + EXT4_SB(sb)->s_inode_readahead_blks;
 			num = EXT4_INODES_PER_GROUP(sb);
-			if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+			if (ext4_has_group_desc_csum(sb))
 				num -= ext4_itable_unused_count(sb, gdp);
 			table += num / inodes_per_block;
 			if (end > table)
@@ -3646,6 +3712,39 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 	if (ret < 0)
 		goto bad_inode;
 	raw_inode = ext4_raw_inode(&iloc);
+
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
+		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
+		    EXT4_INODE_SIZE(inode->i_sb)) {
+			EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
+				EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
+				EXT4_INODE_SIZE(inode->i_sb));
+			ret = -EIO;
+			goto bad_inode;
+		}
+	} else
+		ei->i_extra_isize = 0;
+
+	/* Precompute checksum seed for inode metadata */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+		__u32 csum;
+		__le32 inum = cpu_to_le32(inode->i_ino);
+		__le32 gen = raw_inode->i_generation;
+		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
+				   sizeof(inum));
+		ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
+					      sizeof(gen));
+	}
+
+	if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
+		EXT4_ERROR_INODE(inode, "checksum invalid");
+		ret = -EIO;
+		goto bad_inode;
+	}
+
 	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 	i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
 	i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
@@ -3725,12 +3824,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 	}
 
 	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
-		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
-		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
-		    EXT4_INODE_SIZE(inode->i_sb)) {
-			ret = -EIO;
-			goto bad_inode;
-		}
 		if (ei->i_extra_isize == 0) {
 			/* The extra space is currently unused. Use it. */
 			ei->i_extra_isize = sizeof(struct ext4_inode) -
@@ -3742,8 +3835,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 			if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
 				ext4_set_inode_state(inode, EXT4_STATE_XATTR);
 		}
-	} else
-		ei->i_extra_isize = 0;
+	}
 
 	EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
 	EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
@@ -3942,7 +4034,7 @@ 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);
@@ -3969,6 +4061,8 @@ static int ext4_do_update_inode(handle_t *handle,
 		raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
 	}
 
+	ext4_inode_csum_set(inode, raw_inode, ei);
+
 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
 	rc = ext4_handle_dirty_metadata(handle, NULL, bh);
 	if (!err)
@@ -4213,7 +4307,8 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	 * will return the blocks that include the delayed allocation
 	 * blocks for this file.
 	 */
-	delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
+	delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
+				EXT4_I(inode)->i_reserved_data_blocks);
 
 	stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
 	return 0;

fs/ext4/ioctl.c

@@ -38,7 +38,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		handle_t *handle = NULL;
 		int err, migrate = 0;
 		struct ext4_iloc iloc;
-		unsigned int oldflags;
+		unsigned int oldflags, mask, i;
 		unsigned int jflag;
 
 		if (!inode_owner_or_capable(inode))
@@ -115,8 +115,14 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		if (err)
 			goto flags_err;
 
-		flags = flags & EXT4_FL_USER_MODIFIABLE;
-		flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
+		for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
+			if (!(mask & EXT4_FL_USER_MODIFIABLE))
+				continue;
+			if (mask & flags)
+				ext4_set_inode_flag(inode, i);
+			else
+				ext4_clear_inode_flag(inode, i);
+		}
 		ei->i_flags = flags;
 
 		ext4_set_inode_flags(inode);
@@ -152,6 +158,13 @@ flags_out:
 		if (!inode_owner_or_capable(inode))
 			return -EPERM;
 
+		if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+			ext4_warning(sb, "Setting inode version is not "
+				     "supported with metadata_csum enabled.");
+			return -ENOTTY;
+		}
+
 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;

fs/ext4/mballoc.c

@@ -788,7 +788,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
 	int first_block;
 	struct super_block *sb;
 	struct buffer_head *bhs;
-	struct buffer_head **bh;
+	struct buffer_head **bh = NULL;
 	struct inode *inode;
 	char *data;
 	char *bitmap;
@@ -2375,7 +2375,7 @@ static int ext4_groupinfo_create_slab(size_t size)
 	return 0;
 }
 
-int ext4_mb_init(struct super_block *sb, int needs_recovery)
+int ext4_mb_init(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	unsigned i, j;
@@ -2517,6 +2517,9 @@ int ext4_mb_release(struct super_block *sb)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
 
+	if (sbi->s_proc)
+		remove_proc_entry("mb_groups", sbi->s_proc);
+
 	if (sbi->s_group_info) {
 		for (i = 0; i < ngroups; i++) {
 			grinfo = ext4_get_group_info(sb, i);
@@ -2564,8 +2567,6 @@ int ext4_mb_release(struct super_block *sb)
 	}
 
 	free_percpu(sbi->s_locality_groups);
-	if (sbi->s_proc)
-		remove_proc_entry("mb_groups", sbi->s_proc);
 
 	return 0;
 }
@@ -2797,7 +2798,9 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 	}
 	len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
 	ext4_free_group_clusters_set(sb, gdp, len);
-	gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
+	ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh,
+				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
 
 	ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
 	percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
@@ -3071,13 +3074,9 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
 {
 	struct ext4_prealloc_space *pa = ac->ac_pa;
-	int len;
-
-	if (pa && pa->pa_type == MB_INODE_PA) {
-		len = ac->ac_b_ex.fe_len;
-		pa->pa_free += len;
-	}
 
+	if (pa && pa->pa_type == MB_INODE_PA)
+		pa->pa_free += ac->ac_b_ex.fe_len;
 }
 
 /*
@@ -4636,6 +4635,7 @@ do_more:
 		 */
 		new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS);
 		if (!new_entry) {
+			ext4_mb_unload_buddy(&e4b);
 			err = -ENOMEM;
 			goto error_return;
 		}
@@ -4659,7 +4659,9 @@ do_more:
 
 	ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
 	ext4_free_group_clusters_set(sb, gdp, ret);
-	gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+	ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
+				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
 	ext4_unlock_group(sb, block_group);
 	percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
 
@@ -4803,7 +4805,9 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 	mb_free_blocks(NULL, &e4b, bit, count);
 	blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc);
 	ext4_free_group_clusters_set(sb, desc, blk_free_count);
-	desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
+	ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh,
+				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, desc);
 	ext4_unlock_group(sb, block_group);
 	percpu_counter_add(&sbi->s_freeclusters_counter,
 			   EXT4_B2C(sbi, blocks_freed));

fs/ext4/mmp.c

@@ -6,12 +6,45 @@
 
 #include "ext4.h"
 
+/* Checksumming functions */
+static __u32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int offset = offsetof(struct mmp_struct, mmp_checksum);
+	__u32 csum;
+
+	csum = ext4_chksum(sbi, sbi->s_csum_seed, (char *)mmp, offset);
+
+	return cpu_to_le32(csum);
+}
+
+int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
+{
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);
+}
+
+void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
+{
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);
+}
+
 /*
  * Write the MMP block using WRITE_SYNC to try to get the block on-disk
  * faster.
  */
-static int write_mmp_block(struct buffer_head *bh)
+static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
 {
+	struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
+
+	ext4_mmp_csum_set(sb, mmp);
 	mark_buffer_dirty(bh);
 	lock_buffer(bh);
 	bh->b_end_io = end_buffer_write_sync;
@@ -59,7 +92,8 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
 	}
 
 	mmp = (struct mmp_struct *)((*bh)->b_data);
-	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)
+	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC ||
+	    !ext4_mmp_csum_verify(sb, mmp))
 		return -EINVAL;
 
 	return 0;
@@ -120,7 +154,7 @@ static int kmmpd(void *data)
 		mmp->mmp_time = cpu_to_le64(get_seconds());
 		last_update_time = jiffies;
 
-		retval = write_mmp_block(bh);
+		retval = write_mmp_block(sb, bh);
 		/*
 		 * Don't spew too many error messages. Print one every
 		 * (s_mmp_update_interval * 60) seconds.
@@ -200,7 +234,7 @@ static int kmmpd(void *data)
 	mmp->mmp_seq = cpu_to_le32(EXT4_MMP_SEQ_CLEAN);
 	mmp->mmp_time = cpu_to_le64(get_seconds());
 
-	retval = write_mmp_block(bh);
+	retval = write_mmp_block(sb, bh);
 
 failed:
 	kfree(data);
@@ -299,7 +333,7 @@ skip:
 	seq = mmp_new_seq();
 	mmp->mmp_seq = cpu_to_le32(seq);
 
-	retval = write_mmp_block(bh);
+	retval = write_mmp_block(sb, bh);
 	if (retval)
 		goto failed;
 

fs/ext4/namei.c

@@ -145,6 +145,14 @@ struct dx_map_entry
 	u16 size;
 };
 
+/*
+ * This goes at the end of each htree block.
+ */
+struct dx_tail {
+	u32 dt_reserved;
+	__le32 dt_checksum;	/* crc32c(uuid+inum+dirblock) */
+};
+
 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 static inline unsigned dx_get_hash(struct dx_entry *entry);
@@ -180,6 +188,230 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			     struct inode *inode);
 
+/* checksumming functions */
+#define EXT4_DIRENT_TAIL(block, blocksize) \
+	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
+					((blocksize) - \
+					 sizeof(struct ext4_dir_entry_tail))))
+
+static void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
+				   unsigned int blocksize)
+{
+	memset(t, 0, sizeof(struct ext4_dir_entry_tail));
+	t->det_rec_len = ext4_rec_len_to_disk(
+			sizeof(struct ext4_dir_entry_tail), blocksize);
+	t->det_reserved_ft = EXT4_FT_DIR_CSUM;
+}
+
+/* Walk through a dirent block to find a checksum "dirent" at the tail */
+static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
+						   struct ext4_dir_entry *de)
+{
+	struct ext4_dir_entry_tail *t;
+
+#ifdef PARANOID
+	struct ext4_dir_entry *d, *top;
+
+	d = de;
+	top = (struct ext4_dir_entry *)(((void *)de) +
+		(EXT4_BLOCK_SIZE(inode->i_sb) -
+		sizeof(struct ext4_dir_entry_tail)));
+	while (d < top && d->rec_len)
+		d = (struct ext4_dir_entry *)(((void *)d) +
+		    le16_to_cpu(d->rec_len));
+
+	if (d != top)
+		return NULL;
+
+	t = (struct ext4_dir_entry_tail *)d;
+#else
+	t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
+#endif
+
+	if (t->det_reserved_zero1 ||
+	    le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
+	    t->det_reserved_zero2 ||
+	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
+		return NULL;
+
+	return t;
+}
+
+static __le32 ext4_dirent_csum(struct inode *inode,
+			       struct ext4_dir_entry *dirent, int size)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	__u32 csum;
+
+	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
+	return cpu_to_le32(csum);
+}
+
+int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	t = get_dirent_tail(inode, dirent);
+	if (!t) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
+				 "leaf for checksum.  Please run e2fsck -D.");
+		return 0;
+	}
+
+	if (t->det_checksum != ext4_dirent_csum(inode, dirent,
+						(void *)t - (void *)dirent))
+		return 0;
+
+	return 1;
+}
+
+static void ext4_dirent_csum_set(struct inode *inode,
+				 struct ext4_dir_entry *dirent)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	t = get_dirent_tail(inode, dirent);
+	if (!t) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
+				 "leaf for checksum.  Please run e2fsck -D.");
+		return;
+	}
+
+	t->det_checksum = ext4_dirent_csum(inode, dirent,
+					   (void *)t - (void *)dirent);
+}
+
+static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
+						struct inode *inode,
+						struct buffer_head *bh)
+{
+	ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
+static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
+					       struct ext4_dir_entry *dirent,
+					       int *offset)
+{
+	struct ext4_dir_entry *dp;
+	struct dx_root_info *root;
+	int count_offset;
+
+	if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
+		count_offset = 8;
+	else if (le16_to_cpu(dirent->rec_len) == 12) {
+		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
+		if (le16_to_cpu(dp->rec_len) !=
+		    EXT4_BLOCK_SIZE(inode->i_sb) - 12)
+			return NULL;
+		root = (struct dx_root_info *)(((void *)dp + 12));
+		if (root->reserved_zero ||
+		    root->info_length != sizeof(struct dx_root_info))
+			return NULL;
+		count_offset = 32;
+	} else
+		return NULL;
+
+	if (offset)
+		*offset = count_offset;
+	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
+}
+
+static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
+			   int count_offset, int count, struct dx_tail *t)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	__u32 csum, old_csum;
+	int size;
+
+	size = count_offset + (count * sizeof(struct dx_entry));
+	old_csum = t->dt_checksum;
+	t->dt_checksum = 0;
+	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
+	csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
+	t->dt_checksum = old_csum;
+
+	return cpu_to_le32(csum);
+}
+
+static int ext4_dx_csum_verify(struct inode *inode,
+			       struct ext4_dir_entry *dirent)
+{
+	struct dx_countlimit *c;
+	struct dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	c = get_dx_countlimit(inode, dirent, &count_offset);
+	if (!c) {
+		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
+		return 1;
+	}
+	limit = le16_to_cpu(c->limit);
+	count = le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct dx_entry)) >
+	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
+				 "tree checksum found.  Run e2fsck -D.");
+		return 1;
+	}
+	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
+					    count, t))
+		return 0;
+	return 1;
+}
+
+static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
+{
+	struct dx_countlimit *c;
+	struct dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	c = get_dx_countlimit(inode, dirent, &count_offset);
+	if (!c) {
+		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
+		return;
+	}
+	limit = le16_to_cpu(c->limit);
+	count = le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct dx_entry)) >
+	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
+				 "tree checksum.  Run e2fsck -D.");
+		return;
+	}
+	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
+}
+
+static inline int ext4_handle_dirty_dx_node(handle_t *handle,
+					    struct inode *inode,
+					    struct buffer_head *bh)
+{
+	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
 /*
  * p is at least 6 bytes before the end of page
  */
@@ -239,12 +471,20 @@ static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 {
 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 		EXT4_DIR_REC_LEN(2) - infosize;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		entry_space -= sizeof(struct dx_tail);
 	return entry_space / sizeof(struct dx_entry);
 }
 
 static inline unsigned dx_node_limit(struct inode *dir)
 {
 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		entry_space -= sizeof(struct dx_tail);
 	return entry_space / sizeof(struct dx_entry);
 }
 
@@ -390,6 +630,15 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
 		goto fail;
 	}
 
+	if (!buffer_verified(bh) &&
+	    !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
+		ext4_warning(dir->i_sb, "Root failed checksum");
+		brelse(bh);
+		*err = ERR_BAD_DX_DIR;
+		goto fail;
+	}
+	set_buffer_verified(bh);
+
 	entries = (struct dx_entry *) (((char *)&root->info) +
 				       root->info.info_length);
 
@@ -450,6 +699,17 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
 		if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 			goto fail2;
 		at = entries = ((struct dx_node *) bh->b_data)->entries;
+
+		if (!buffer_verified(bh) &&
+		    !ext4_dx_csum_verify(dir,
+					 (struct ext4_dir_entry *)bh->b_data)) {
+			ext4_warning(dir->i_sb, "Node failed checksum");
+			brelse(bh);
+			*err = ERR_BAD_DX_DIR;
+			goto fail;
+		}
+		set_buffer_verified(bh);
+
 		if (dx_get_limit(entries) != dx_node_limit (dir)) {
 			ext4_warning(dir->i_sb,
 				     "dx entry: limit != node limit");
@@ -549,6 +809,15 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 		if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 				      0, &err)))
 			return err; /* Failure */
+
+		if (!buffer_verified(bh) &&
+		    !ext4_dx_csum_verify(dir,
+					 (struct ext4_dir_entry *)bh->b_data)) {
+			ext4_warning(dir->i_sb, "Node failed checksum");
+			return -EIO;
+		}
+		set_buffer_verified(bh);
+
 		p++;
 		brelse(p->bh);
 		p->bh = bh;
@@ -577,6 +846,11 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 		return err;
 
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
+		return -EIO;
+	set_buffer_verified(bh);
+
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	top = (struct ext4_dir_entry_2 *) ((char *) de +
 					   dir->i_sb->s_blocksize -
@@ -936,6 +1210,15 @@ restart:
 			brelse(bh);
 			goto next;
 		}
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_INODE(dir, "checksumming directory "
+					 "block %lu", (unsigned long)block);
+			brelse(bh);
+			goto next;
+		}
+		set_buffer_verified(bh);
 		i = search_dirblock(bh, dir, d_name,
 			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 		if (i == 1) {
@@ -987,6 +1270,16 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
 		if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
 			goto errout;
 
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_INODE(dir, "checksumming directory "
+					 "block %lu", (unsigned long)block);
+			brelse(bh);
+			*err = -EIO;
+			goto errout;
+		}
+		set_buffer_verified(bh);
 		retval = search_dirblock(bh, dir, d_name,
 					 block << EXT4_BLOCK_SIZE_BITS(sb),
 					 res_dir);
@@ -1037,6 +1330,12 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
 			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
 			return ERR_PTR(-EIO);
 		}
+		if (unlikely(ino == dir->i_ino)) {
+			EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
+					 dentry->d_name.len,
+					 dentry->d_name.name);
+			return ERR_PTR(-EIO);
+		}
 		inode = ext4_iget(dir->i_sb, ino);
 		if (inode == ERR_PTR(-ESTALE)) {
 			EXT4_ERROR_INODE(dir,
@@ -1156,8 +1455,14 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	char *data1 = (*bh)->b_data, *data2;
 	unsigned split, move, size;
 	struct ext4_dir_entry_2 *de = NULL, *de2;
+	struct ext4_dir_entry_tail *t;
+	int	csum_size = 0;
 	int	err = 0, i;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	bh2 = ext4_append (handle, dir, &newblock, &err);
 	if (!(bh2)) {
 		brelse(*bh);
@@ -1204,10 +1509,20 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	/* Fancy dance to stay within two buffers */
 	de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
 	de = dx_pack_dirents(data1, blocksize);
-	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
+					   (char *) de,
 					   blocksize);
-	de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
+	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
+					    (char *) de2,
 					    blocksize);
+	if (csum_size) {
+		t = EXT4_DIRENT_TAIL(data2, blocksize);
+		initialize_dirent_tail(t, blocksize);
+
+		t = EXT4_DIRENT_TAIL(data1, blocksize);
+		initialize_dirent_tail(t, blocksize);
+	}
+
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
 
@@ -1218,10 +1533,10 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 		de = de2;
 	}
 	dx_insert_block(frame, hash2 + continued, newblock);
-	err = ext4_handle_dirty_metadata(handle, dir, bh2);
+	err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
 	if (err)
 		goto journal_error;
-	err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
+	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
 	if (err)
 		goto journal_error;
 	brelse(bh2);
@@ -1258,11 +1573,16 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	unsigned short	reclen;
 	int		nlen, rlen, err;
 	char		*top;
+	int		csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	reclen = EXT4_DIR_REC_LEN(namelen);
 	if (!de) {
 		de = (struct ext4_dir_entry_2 *)bh->b_data;
-		top = bh->b_data + blocksize - reclen;
+		top = bh->b_data + (blocksize - csum_size) - reclen;
 		while ((char *) de <= top) {
 			if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
 				return -EIO;
@@ -1295,11 +1615,8 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 		de = de1;
 	}
 	de->file_type = EXT4_FT_UNKNOWN;
-	if (inode) {
-		de->inode = cpu_to_le32(inode->i_ino);
-		ext4_set_de_type(dir->i_sb, de, inode->i_mode);
-	} else
-		de->inode = 0;
+	de->inode = cpu_to_le32(inode->i_ino);
+	ext4_set_de_type(dir->i_sb, de, inode->i_mode);
 	de->name_len = namelen;
 	memcpy(de->name, name, namelen);
 	/*
@@ -1318,7 +1635,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-	err = ext4_handle_dirty_metadata(handle, dir, bh);
+	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
 	if (err)
 		ext4_std_error(dir->i_sb, err);
 	return 0;
@@ -1339,6 +1656,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	struct dx_frame	frames[2], *frame;
 	struct dx_entry *entries;
 	struct ext4_dir_entry_2	*de, *de2;
+	struct ext4_dir_entry_tail *t;
 	char		*data1, *top;
 	unsigned	len;
 	int		retval;
@@ -1346,6 +1664,11 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	struct dx_hash_info hinfo;
 	ext4_lblk_t  block;
 	struct fake_dirent *fde;
+	int		csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	blocksize =  dir->i_sb->s_blocksize;
 	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
@@ -1366,7 +1689,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 		brelse(bh);
 		return -EIO;
 	}
-	len = ((char *) root) + blocksize - (char *) de;
+	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 
 	/* Allocate new block for the 0th block's dirents */
 	bh2 = ext4_append(handle, dir, &block, &retval);
@@ -1382,8 +1705,15 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	top = data1 + len;
 	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
 		de = de2;
-	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
+					   (char *) de,
 					   blocksize);
+
+	if (csum_size) {
+		t = EXT4_DIRENT_TAIL(data1, blocksize);
+		initialize_dirent_tail(t, blocksize);
+	}
+
 	/* Initialize the root; the dot dirents already exist */
 	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
@@ -1408,8 +1738,8 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	frame->bh = bh;
 	bh = bh2;
 
-	ext4_handle_dirty_metadata(handle, dir, frame->bh);
-	ext4_handle_dirty_metadata(handle, dir, bh);
+	ext4_handle_dirty_dx_node(handle, dir, frame->bh);
+	ext4_handle_dirty_dirent_node(handle, dir, bh);
 
 	de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
 	if (!de) {
@@ -1445,11 +1775,17 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 	struct inode *dir = dentry->d_parent->d_inode;
 	struct buffer_head *bh;
 	struct ext4_dir_entry_2 *de;
+	struct ext4_dir_entry_tail *t;
 	struct super_block *sb;
 	int	retval;
 	int	dx_fallback=0;
 	unsigned blocksize;
 	ext4_lblk_t block, blocks;
+	int	csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	sb = dir->i_sb;
 	blocksize = sb->s_blocksize;
@@ -1468,6 +1804,11 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 		bh = ext4_bread(handle, dir, block, 0, &retval);
 		if(!bh)
 			return retval;
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data))
+			return -EIO;
+		set_buffer_verified(bh);
 		retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
 		if (retval != -ENOSPC) {
 			brelse(bh);
@@ -1484,7 +1825,13 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 		return retval;
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de->inode = 0;
-	de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
+	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
+
+	if (csum_size) {
+		t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
+		initialize_dirent_tail(t, blocksize);
+	}
+
 	retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
 	brelse(bh);
 	if (retval == 0)
@@ -1516,6 +1863,11 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 	if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
 		goto cleanup;
 
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
+		goto journal_error;
+	set_buffer_verified(bh);
+
 	BUFFER_TRACE(bh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, bh);
 	if (err)
@@ -1583,7 +1935,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			dxtrace(dx_show_index("node", frames[1].entries));
 			dxtrace(dx_show_index("node",
 			       ((struct dx_node *) bh2->b_data)->entries));
-			err = ext4_handle_dirty_metadata(handle, dir, bh2);
+			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
 			if (err)
 				goto journal_error;
 			brelse (bh2);
@@ -1609,7 +1961,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			if (err)
 				goto journal_error;
 		}
-		err = ext4_handle_dirty_metadata(handle, dir, frames[0].bh);
+		err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
 		if (err) {
 			ext4_std_error(inode->i_sb, err);
 			goto cleanup;
@@ -1641,12 +1993,17 @@ static int ext4_delete_entry(handle_t *handle,
 {
 	struct ext4_dir_entry_2 *de, *pde;
 	unsigned int blocksize = dir->i_sb->s_blocksize;
+	int csum_size = 0;
 	int i, err;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	i = 0;
 	pde = NULL;
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
-	while (i < bh->b_size) {
+	while (i < bh->b_size - csum_size) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh, i))
 			return -EIO;
 		if (de == de_del)  {
@@ -1667,7 +2024,7 @@ static int ext4_delete_entry(handle_t *handle,
 				de->inode = 0;
 			dir->i_version++;
 			BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-			err = ext4_handle_dirty_metadata(handle, dir, bh);
+			err = ext4_handle_dirty_dirent_node(handle, dir, bh);
 			if (unlikely(err)) {
 				ext4_std_error(dir->i_sb, err);
 				return err;
@@ -1809,9 +2166,15 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	struct inode *inode;
 	struct buffer_head *dir_block = NULL;
 	struct ext4_dir_entry_2 *de;
+	struct ext4_dir_entry_tail *t;
 	unsigned int blocksize = dir->i_sb->s_blocksize;
+	int csum_size = 0;
 	int err, retries = 0;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	if (EXT4_DIR_LINK_MAX(dir))
 		return -EMLINK;
 
@@ -1852,16 +2215,24 @@ retry:
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 	de = ext4_next_entry(de, blocksize);
 	de->inode = cpu_to_le32(dir->i_ino);
-	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
+	de->rec_len = ext4_rec_len_to_disk(blocksize -
+					   (csum_size + EXT4_DIR_REC_LEN(1)),
 					   blocksize);
 	de->name_len = 2;
 	strcpy(de->name, "..");
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 	set_nlink(inode, 2);
+
+	if (csum_size) {
+		t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
+		initialize_dirent_tail(t, blocksize);
+	}
+
 	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
-	err = ext4_handle_dirty_metadata(handle, inode, dir_block);
+	err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
 	if (err)
 		goto out_clear_inode;
+	set_buffer_verified(dir_block);
 	err = ext4_mark_inode_dirty(handle, inode);
 	if (!err)
 		err = ext4_add_entry(handle, dentry, inode);
@@ -1911,6 +2282,14 @@ static int empty_dir(struct inode *inode)
 				     inode->i_ino);
 		return 1;
 	}
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(inode,
+			(struct ext4_dir_entry *)bh->b_data)) {
+		EXT4_ERROR_INODE(inode, "checksum error reading directory "
+				 "lblock 0");
+		return -EIO;
+	}
+	set_buffer_verified(bh);
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de1 = ext4_next_entry(de, sb->s_blocksize);
 	if (le32_to_cpu(de->inode) != inode->i_ino ||
@@ -1942,6 +2321,14 @@ static int empty_dir(struct inode *inode)
 				offset += sb->s_blocksize;
 				continue;
 			}
+			if (!buffer_verified(bh) &&
+			    !ext4_dirent_csum_verify(inode,
+					(struct ext4_dir_entry *)bh->b_data)) {
+				EXT4_ERROR_INODE(inode, "checksum error "
+						 "reading directory lblock 0");
+				return -EIO;
+			}
+			set_buffer_verified(bh);
 			de = (struct ext4_dir_entry_2 *) bh->b_data;
 		}
 		if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
@@ -2010,7 +2397,7 @@ 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;
@@ -2083,7 +2470,7 @@ 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 =
@@ -2442,6 +2829,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
 		if (!dir_bh)
 			goto end_rename;
+		if (!buffer_verified(dir_bh) &&
+		    !ext4_dirent_csum_verify(old_inode,
+				(struct ext4_dir_entry *)dir_bh->b_data))
+			goto end_rename;
+		set_buffer_verified(dir_bh);
 		if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
 				old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
 			goto end_rename;
@@ -2472,7 +2864,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 					ext4_current_time(new_dir);
 		ext4_mark_inode_dirty(handle, new_dir);
 		BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
-		retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
+		retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
 		if (unlikely(retval)) {
 			ext4_std_error(new_dir->i_sb, retval);
 			goto end_rename;
@@ -2526,7 +2918,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
 						cpu_to_le32(new_dir->i_ino);
 		BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
-		retval = ext4_handle_dirty_metadata(handle, old_inode, dir_bh);
+		retval = ext4_handle_dirty_dirent_node(handle, old_inode,
+						       dir_bh);
 		if (retval) {
 			ext4_std_error(old_dir->i_sb, retval);
 			goto end_rename;

fs/ext4/resize.c

@@ -161,6 +161,8 @@ static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
 	if (flex_gd == NULL)
 		goto out3;
 
+	if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
+		goto out2;
 	flex_gd->count = flexbg_size;
 
 	flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
@@ -796,7 +798,7 @@ 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 +970,8 @@ 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;
 
@@ -1067,6 +1071,54 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 	return err;
 }
 
+static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
+{
+	struct buffer_head *bh = sb_getblk(sb, block);
+	if (!bh)
+		return NULL;
+
+	if (bitmap_uptodate(bh))
+		return bh;
+
+	lock_buffer(bh);
+	if (bh_submit_read(bh) < 0) {
+		unlock_buffer(bh);
+		brelse(bh);
+		return NULL;
+	}
+	unlock_buffer(bh);
+
+	return bh;
+}
+
+static int ext4_set_bitmap_checksums(struct super_block *sb,
+				     ext4_group_t group,
+				     struct ext4_group_desc *gdp,
+				     struct ext4_new_group_data *group_data)
+{
+	struct buffer_head *bh;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 0;
+
+	bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
+	if (!bh)
+		return -EIO;
+	ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
+				   EXT4_INODES_PER_GROUP(sb) / 8);
+	brelse(bh);
+
+	bh = ext4_get_bitmap(sb, group_data->block_bitmap);
+	if (!bh)
+		return -EIO;
+	ext4_block_bitmap_csum_set(sb, group, gdp, bh,
+				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	brelse(bh);
+
+	return 0;
+}
+
 /*
  * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
  */
@@ -1093,18 +1145,24 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
 		 */
 		gdb_bh = sbi->s_group_desc[gdb_num];
 		/* Update group descriptor block for new group */
-		gdp = (struct ext4_group_desc *)((char *)gdb_bh->b_data +
+		gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
 						 gdb_off * EXT4_DESC_SIZE(sb));
 
 		memset(gdp, 0, EXT4_DESC_SIZE(sb));
 		ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
 		ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
+		err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
+		if (err) {
+			ext4_std_error(sb, err);
+			break;
+		}
+
 		ext4_inode_table_set(sb, gdp, group_data->inode_table);
 		ext4_free_group_clusters_set(sb, gdp,
 					     EXT4_B2C(sbi, group_data->free_blocks_count));
 		ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
 		gdp->bg_flags = cpu_to_le16(*bg_flags);
-		gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+		ext4_group_desc_csum_set(sb, group, gdp);
 
 		err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
 		if (unlikely(err)) {
@@ -1343,17 +1401,14 @@ static int ext4_setup_next_flex_gd(struct super_block *sb,
 			   (1 + ext4_bg_num_gdb(sb, group + i) +
 			    le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
 		group_data[i].free_blocks_count = blocks_per_group - overhead;
-		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
-					       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+		if (ext4_has_group_desc_csum(sb))
 			flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
 					       EXT4_BG_INODE_UNINIT;
 		else
 			flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
 	}
 
-	if (last_group == n_group &&
-	    EXT4_HAS_RO_COMPAT_FEATURE(sb,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+	if (last_group == n_group && ext4_has_group_desc_csum(sb))
 		/* We need to initialize block bitmap of last group. */
 		flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
 

fs/ext4/super.c

@@ -112,6 +112,48 @@ static struct file_system_type ext3_fs_type = {
 #define IS_EXT3_SB(sb) (0)
 #endif
 
+static int ext4_verify_csum_type(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_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;
@@ -497,6 +539,7 @@ void __ext4_error(struct super_block *sb, const char *function,
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 	       sb->s_id, function, line, current->comm, &vaf);
 	va_end(args);
+	save_error_info(sb, function, line);
 
 	ext4_handle_error(sb);
 }
@@ -905,6 +948,8 @@ static void ext4_put_super(struct super_block *sb)
 	unlock_super(sb);
 	kobject_put(&sbi->s_kobj);
 	wait_for_completion(&sbi->s_kobj_unregister);
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi);
 }
@@ -1922,43 +1967,69 @@ failed:
 	return 0;
 }
 
-__le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
-			    struct ext4_group_desc *gdp)
+static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
+				   struct ext4_group_desc *gdp)
 {
+	int offset;
 	__u16 crc = 0;
+	__le32 le_group = cpu_to_le32(block_group);
 
-	if (sbi->s_es->s_feature_ro_compat &
-	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
-		int offset = offsetof(struct ext4_group_desc, bg_checksum);
-		__le32 le_group = cpu_to_le32(block_group);
-
-		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
-		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
-		crc = crc16(crc, (__u8 *)gdp, offset);
-		offset += sizeof(gdp->bg_checksum); /* skip checksum */
-		/* for checksum of struct ext4_group_desc do the rest...*/
-		if ((sbi->s_es->s_feature_incompat &
-		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
-		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
-			crc = crc16(crc, (__u8 *)gdp + offset,
-				    le16_to_cpu(sbi->s_es->s_desc_size) -
-					offset);
+	if ((sbi->s_es->s_feature_ro_compat &
+	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
+		/* Use new metadata_csum algorithm */
+		__u16 old_csum;
+		__u32 csum32;
+
+		old_csum = gdp->bg_checksum;
+		gdp->bg_checksum = 0;
+		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
+				     sizeof(le_group));
+		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
+				     sbi->s_desc_size);
+		gdp->bg_checksum = old_csum;
+
+		crc = csum32 & 0xFFFF;
+		goto out;
 	}
 
+	/* old crc16 code */
+	offset = offsetof(struct ext4_group_desc, bg_checksum);
+
+	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
+	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
+	crc = crc16(crc, (__u8 *)gdp, offset);
+	offset += sizeof(gdp->bg_checksum); /* skip checksum */
+	/* for checksum of struct ext4_group_desc do the rest...*/
+	if ((sbi->s_es->s_feature_incompat &
+	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
+	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
+		crc = crc16(crc, (__u8 *)gdp + offset,
+			    le16_to_cpu(sbi->s_es->s_desc_size) -
+				offset);
+
+out:
 	return cpu_to_le16(crc);
 }
 
-int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
+int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
 				struct ext4_group_desc *gdp)
 {
-	if ((sbi->s_es->s_feature_ro_compat &
-	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
-	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
+	if (ext4_has_group_desc_csum(sb) &&
+	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
+						      block_group, gdp)))
 		return 0;
 
 	return 1;
 }
 
+void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
+			      struct ext4_group_desc *gdp)
+{
+	if (!ext4_has_group_desc_csum(sb))
+		return;
+	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
+}
+
 /* Called at mount-time, super-block is locked */
 static int ext4_check_descriptors(struct super_block *sb,
 				  ext4_group_t *first_not_zeroed)
@@ -2013,7 +2084,7 @@ static int ext4_check_descriptors(struct super_block *sb,
 			return 0;
 		}
 		ext4_lock_group(sb, i);
-		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
+		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
 				 "Checksum for group %u failed (%u!=%u)",
 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
@@ -2417,6 +2488,23 @@ static ssize_t sbi_ui_store(struct ext4_attr *a,
 	return count;
 }
 
+static ssize_t trigger_test_error(struct ext4_attr *a,
+				  struct ext4_sb_info *sbi,
+				  const char *buf, size_t count)
+{
+	int len = count;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (len && buf[len-1] == '\n')
+		len--;
+
+	if (len)
+		ext4_error(sbi->s_sb, "%.*s", len, buf);
+	return count;
+}
+
 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
 static struct ext4_attr ext4_attr_##_name = {			\
 	.attr = {.name = __stringify(_name), .mode = _mode },	\
@@ -2447,6 +2535,7 @@ EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
+EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
 
 static struct attribute *ext4_attrs[] = {
 	ATTR_LIST(delayed_allocation_blocks),
@@ -2461,6 +2550,7 @@ static struct attribute *ext4_attrs[] = {
 	ATTR_LIST(mb_stream_req),
 	ATTR_LIST(mb_group_prealloc),
 	ATTR_LIST(max_writeback_mb_bump),
+	ATTR_LIST(trigger_fs_error),
 	NULL,
 };
 
@@ -2957,6 +3047,44 @@ static void ext4_destroy_lazyinit_thread(void)
 	kthread_stop(ext4_lazyinit_task);
 }
 
+static int set_journal_csum_feature_set(struct super_block *sb)
+{
+	int ret = 1;
+	int compat, incompat;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+		/* journal checksum v2 */
+		compat = 0;
+		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
+	} else {
+		/* journal checksum v1 */
+		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
+		incompat = 0;
+	}
+
+	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+		ret = jbd2_journal_set_features(sbi->s_journal,
+				compat, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
+				incompat);
+	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
+		ret = jbd2_journal_set_features(sbi->s_journal,
+				compat, 0,
+				incompat);
+		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	} else {
+		jbd2_journal_clear_features(sbi->s_journal,
+				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
+				JBD2_FEATURE_INCOMPAT_CSUM_V2);
+	}
+
+	return ret;
+}
+
 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 {
 	char *orig_data = kstrdup(data, GFP_KERNEL);
@@ -2993,6 +3121,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto out_free_orig;
 	}
 	sb->s_fs_info = sbi;
+	sbi->s_sb = sb;
 	sbi->s_mount_opt = 0;
 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
@@ -3032,13 +3161,54 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	 * Note: s_es must be initialized as soon as possible because
 	 *       some ext4 macro-instructions depend on its value
 	 */
-	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
+	es = (struct ext4_super_block *) (bh->b_data + offset);
 	sbi->s_es = es;
 	sb->s_magic = le16_to_cpu(es->s_magic);
 	if (sb->s_magic != EXT4_SUPER_MAGIC)
 		goto cantfind_ext4;
 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
 
+	/* Warn if metadata_csum and gdt_csum are both set. */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
+			     "redundant flags; please run fsck.");
+
+	/* Check for a known checksum algorithm */
+	if (!ext4_verify_csum_type(sb, es)) {
+		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
+			 "unknown checksum algorithm.");
+		silent = 1;
+		goto cantfind_ext4;
+	}
+
+	/* Load the checksum driver */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+		if (IS_ERR(sbi->s_chksum_driver)) {
+			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
+			ret = PTR_ERR(sbi->s_chksum_driver);
+			sbi->s_chksum_driver = NULL;
+			goto failed_mount;
+		}
+	}
+
+	/* 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);
@@ -3200,7 +3370,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			       "Can't read superblock on 2nd try");
 			goto failed_mount;
 		}
-		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
+		es = (struct ext4_super_block *)(bh->b_data + offset);
 		sbi->s_es = es;
 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
 			ext4_msg(sb, KERN_ERR,
@@ -3392,6 +3562,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 					  GFP_KERNEL);
 	if (sbi->s_group_desc == NULL) {
 		ext4_msg(sb, KERN_ERR, "not enough memory");
+		ret = -ENOMEM;
 		goto failed_mount;
 	}
 
@@ -3449,6 +3620,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "insufficient memory");
+		ret = err;
 		goto failed_mount3;
 	}
 
@@ -3506,26 +3678,17 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto no_journal;
 	}
 
-	if (ext4_blocks_count(es) > 0xffffffffULL &&
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
 		goto failed_mount_wq;
 	}
 
-	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
-		jbd2_journal_set_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
-				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
-		jbd2_journal_set_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
-		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
-				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-	} else {
-		jbd2_journal_clear_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
-				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	if (!set_journal_csum_feature_set(sb)) {
+		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
+			 "feature set");
+		goto failed_mount_wq;
 	}
 
 	/* We have now updated the journal if required, so we can
@@ -3606,7 +3769,8 @@ no_journal:
 		goto failed_mount4;
 	}
 
-	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
+	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
+		sb->s_flags |= MS_RDONLY;
 
 	/* determine the minimum size of new large inodes, if present */
 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
@@ -3641,7 +3805,7 @@ no_journal:
 	}
 
 	ext4_ext_init(sb);
-	err = ext4_mb_init(sb, needs_recovery);
+	err = ext4_mb_init(sb);
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
 			 err);
@@ -3724,6 +3888,8 @@ failed_mount2:
 		brelse(sbi->s_group_desc[i]);
 	ext4_kvfree(sbi->s_group_desc);
 failed_mount:
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
 	if (sbi->s_proc) {
 		remove_proc_entry("options", sbi->s_proc);
 		remove_proc_entry(sb->s_id, ext4_proc_root);
@@ -3847,7 +4013,7 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
 		goto out_bdev;
 	}
 
-	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
+	es = (struct ext4_super_block *) (bh->b_data + offset);
 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
 	    !(le32_to_cpu(es->s_feature_incompat) &
 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
@@ -4039,6 +4205,7 @@ 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);
@@ -4333,7 +4500,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 				struct ext4_group_desc *gdp =
 					ext4_get_group_desc(sb, g, NULL);
 
-				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
+				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
 					ext4_msg(sb, KERN_ERR,
 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),

fs/ext4/xattr.c

@@ -122,6 +122,58 @@ const struct xattr_handler *ext4_xattr_handlers[] = {
 	NULL
 };
 
+static __le32 ext4_xattr_block_csum(struct inode *inode,
+				    sector_t block_nr,
+				    struct ext4_xattr_header *hdr)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	__u32 csum, old;
+
+	old = hdr->h_checksum;
+	hdr->h_checksum = 0;
+	if (le32_to_cpu(hdr->h_refcount) != 1) {
+		block_nr = cpu_to_le64(block_nr);
+		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&block_nr,
+				   sizeof(block_nr));
+	} else
+		csum = ei->i_csum_seed;
+	csum = ext4_chksum(sbi, csum, (__u8 *)hdr,
+			   EXT4_BLOCK_SIZE(inode->i_sb));
+	hdr->h_checksum = old;
+	return cpu_to_le32(csum);
+}
+
+static int ext4_xattr_block_csum_verify(struct inode *inode,
+					sector_t block_nr,
+					struct ext4_xattr_header *hdr)
+{
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+	    (hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr)))
+		return 0;
+	return 1;
+}
+
+static void ext4_xattr_block_csum_set(struct inode *inode,
+				      sector_t block_nr,
+				      struct ext4_xattr_header *hdr)
+{
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr);
+}
+
+static inline int ext4_handle_dirty_xattr_block(handle_t *handle,
+						struct inode *inode,
+						struct buffer_head *bh)
+{
+	ext4_xattr_block_csum_set(inode, bh->b_blocknr, BHDR(bh));
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
 static inline const struct xattr_handler *
 ext4_xattr_handler(int name_index)
 {
@@ -156,12 +208,22 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
 }
 
 static inline int
-ext4_xattr_check_block(struct buffer_head *bh)
+ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
 {
+	int error;
+
+	if (buffer_verified(bh))
+		return 0;
+
 	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
 	    BHDR(bh)->h_blocks != cpu_to_le32(1))
 		return -EIO;
-	return ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
+	if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
+		return -EIO;
+	error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
+	if (!error)
+		set_buffer_verified(bh);
+	return error;
 }
 
 static inline int
@@ -224,7 +286,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
 		goto cleanup;
 	ea_bdebug(bh, "b_count=%d, refcount=%d",
 		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
-	if (ext4_xattr_check_block(bh)) {
+	if (ext4_xattr_check_block(inode, bh)) {
 bad_block:
 		EXT4_ERROR_INODE(inode, "bad block %llu",
 				 EXT4_I(inode)->i_file_acl);
@@ -369,7 +431,7 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 		goto cleanup;
 	ea_bdebug(bh, "b_count=%d, refcount=%d",
 		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
-	if (ext4_xattr_check_block(bh)) {
+	if (ext4_xattr_check_block(inode, bh)) {
 		EXT4_ERROR_INODE(inode, "bad block %llu",
 				 EXT4_I(inode)->i_file_acl);
 		error = -EIO;
@@ -492,7 +554,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
 		if (ce)
 			mb_cache_entry_release(ce);
 		unlock_buffer(bh);
-		error = ext4_handle_dirty_metadata(handle, inode, bh);
+		error = ext4_handle_dirty_xattr_block(handle, inode, bh);
 		if (IS_SYNC(inode))
 			ext4_handle_sync(handle);
 		dquot_free_block(inode, 1);
@@ -662,7 +724,7 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
 		ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
 			atomic_read(&(bs->bh->b_count)),
 			le32_to_cpu(BHDR(bs->bh)->h_refcount));
-		if (ext4_xattr_check_block(bs->bh)) {
+		if (ext4_xattr_check_block(inode, bs->bh)) {
 			EXT4_ERROR_INODE(inode, "bad block %llu",
 					 EXT4_I(inode)->i_file_acl);
 			error = -EIO;
@@ -725,9 +787,9 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 			if (error == -EIO)
 				goto bad_block;
 			if (!error)
-				error = ext4_handle_dirty_metadata(handle,
-								   inode,
-								   bs->bh);
+				error = ext4_handle_dirty_xattr_block(handle,
+								      inode,
+								      bs->bh);
 			if (error)
 				goto cleanup;
 			goto inserted;
@@ -796,9 +858,9 @@ inserted:
 				ea_bdebug(new_bh, "reusing; refcount now=%d",
 					le32_to_cpu(BHDR(new_bh)->h_refcount));
 				unlock_buffer(new_bh);
-				error = ext4_handle_dirty_metadata(handle,
-								   inode,
-								   new_bh);
+				error = ext4_handle_dirty_xattr_block(handle,
+								      inode,
+								      new_bh);
 				if (error)
 					goto cleanup_dquot;
 			}
@@ -855,8 +917,8 @@ getblk_failed:
 			set_buffer_uptodate(new_bh);
 			unlock_buffer(new_bh);
 			ext4_xattr_cache_insert(new_bh);
-			error = ext4_handle_dirty_metadata(handle,
-							   inode, new_bh);
+			error = ext4_handle_dirty_xattr_block(handle,
+							      inode, new_bh);
 			if (error)
 				goto cleanup;
 		}
@@ -1193,7 +1255,7 @@ retry:
 		error = -EIO;
 		if (!bh)
 			goto cleanup;
-		if (ext4_xattr_check_block(bh)) {
+		if (ext4_xattr_check_block(inode, bh)) {
 			EXT4_ERROR_INODE(inode, "bad block %llu",
 					 EXT4_I(inode)->i_file_acl);
 			error = -EIO;

fs/ext4/xattr.h

@@ -27,7 +27,9 @@ struct ext4_xattr_header {
 	__le32	h_refcount;	/* reference count */
 	__le32	h_blocks;	/* number of disk blocks used */
 	__le32	h_hash;		/* hash value of all attributes */
-	__u32	h_reserved[4];	/* zero right now */
+	__le32	h_checksum;	/* crc32c(uuid+id+xattrblock) */
+				/* id = inum if refcount=1, blknum otherwise */
+	__u32	h_reserved[3];	/* zero right now */
 };
 
 struct ext4_xattr_ibody_header {

fs/jbd2/Kconfig

@@ -1,6 +1,8 @@
 config JBD2
 	tristate
 	select CRC32
+	select CRYPTO
+	select CRYPTO_CRC32C
 	help
 	  This is a generic journaling layer for block devices that support
 	  both 32-bit and 64-bit block numbers.  It is currently used by

fs/jbd2/commit.c

@@ -85,6 +85,24 @@ nope:
 	__brelse(bh);
 }
 
+static void jbd2_commit_block_csum_set(journal_t *j,
+				       struct journal_head *descriptor)
+{
+	struct commit_header *h;
+	__u32 csum;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return;
+
+	h = (struct commit_header *)(jh2bh(descriptor)->b_data);
+	h->h_chksum_type = 0;
+	h->h_chksum_size = 0;
+	h->h_chksum[0] = 0;
+	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
+			   j->j_blocksize);
+	h->h_chksum[0] = cpu_to_be32(csum);
+}
+
 /*
  * Done it all: now submit the commit record.  We should have
  * cleaned up our previous buffers by now, so if we are in abort
@@ -128,6 +146,7 @@ static int journal_submit_commit_record(journal_t *journal,
 		tmp->h_chksum_size 	= JBD2_CRC32_CHKSUM_SIZE;
 		tmp->h_chksum[0] 	= cpu_to_be32(crc32_sum);
 	}
+	jbd2_commit_block_csum_set(journal, descriptor);
 
 	JBUFFER_TRACE(descriptor, "submit commit block");
 	lock_buffer(bh);
@@ -301,6 +320,44 @@ static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
 		tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
 }
 
+static void jbd2_descr_block_csum_set(journal_t *j,
+				      struct journal_head *descriptor)
+{
+	struct jbd2_journal_block_tail *tail;
+	__u32 csum;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return;
+
+	tail = (struct jbd2_journal_block_tail *)
+			(jh2bh(descriptor)->b_data + j->j_blocksize -
+			sizeof(struct jbd2_journal_block_tail));
+	tail->t_checksum = 0;
+	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
+			   j->j_blocksize);
+	tail->t_checksum = cpu_to_be32(csum);
+}
+
+static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
+				    struct buffer_head *bh, __u32 sequence)
+{
+	struct page *page = bh->b_page;
+	__u8 *addr;
+	__u32 csum;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return;
+
+	sequence = cpu_to_be32(sequence);
+	addr = kmap_atomic(page, KM_USER0);
+	csum = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
+			  sizeof(sequence));
+	csum = jbd2_chksum(j, csum, addr + offset_in_page(bh->b_data),
+			  bh->b_size);
+	kunmap_atomic(addr, KM_USER0);
+
+	tag->t_checksum = cpu_to_be32(csum);
+}
 /*
  * jbd2_journal_commit_transaction
  *
@@ -334,6 +391,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	unsigned long first_block;
 	tid_t first_tid;
 	int update_tail;
+	int csum_size = 0;
+
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		csum_size = sizeof(struct jbd2_journal_block_tail);
 
 	/*
 	 * First job: lock down the current transaction and wait for
@@ -627,7 +688,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
 		tag = (journal_block_tag_t *) tagp;
 		write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
-		tag->t_flags = cpu_to_be32(tag_flag);
+		tag->t_flags = cpu_to_be16(tag_flag);
+		jbd2_block_tag_csum_set(journal, tag, jh2bh(new_jh),
+					commit_transaction->t_tid);
 		tagp += tag_bytes;
 		space_left -= tag_bytes;
 
@@ -643,7 +706,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
 		if (bufs == journal->j_wbufsize ||
 		    commit_transaction->t_buffers == NULL ||
-		    space_left < tag_bytes + 16) {
+		    space_left < tag_bytes + 16 + csum_size) {
 
 			jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
 
@@ -651,8 +714,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                            submitting the IOs.  "tag" still points to
                            the last tag we set up. */
 
-			tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG);
+			tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
 
+			jbd2_descr_block_csum_set(journal, descriptor);
 start_journal_io:
 			for (i = 0; i < bufs; i++) {
 				struct buffer_head *bh = wbuf[i];

fs/jbd2/journal.c

@@ -97,6 +97,43 @@ EXPORT_SYMBOL(jbd2_inode_cache);
 static void __journal_abort_soft (journal_t *journal, int errno);
 static int jbd2_journal_create_slab(size_t slab_size);
 
+/* Checksumming functions */
+int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
+{
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
+}
+
+static __u32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
+{
+	__u32 csum, old_csum;
+
+	old_csum = sb->s_checksum;
+	sb->s_checksum = 0;
+	csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t));
+	sb->s_checksum = old_csum;
+
+	return cpu_to_be32(csum);
+}
+
+int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
+{
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	return sb->s_checksum == jbd2_superblock_csum(j, sb);
+}
+
+void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb)
+{
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return;
+
+	sb->s_checksum = jbd2_superblock_csum(j, sb);
+}
+
 /*
  * Helper function used to manage commit timeouts
  */
@@ -1348,6 +1385,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal)
 	jbd_debug(1, "JBD2: updating superblock error (errno %d)\n",
 		  journal->j_errno);
 	sb->s_errno    = cpu_to_be32(journal->j_errno);
+	jbd2_superblock_csum_set(journal, sb);
 	read_unlock(&journal->j_state_lock);
 
 	jbd2_write_superblock(journal, WRITE_SYNC);
@@ -1376,6 +1414,9 @@ static int journal_get_superblock(journal_t *journal)
 		}
 	}
 
+	if (buffer_verified(bh))
+		return 0;
+
 	sb = journal->j_superblock;
 
 	err = -EINVAL;
@@ -1413,6 +1454,43 @@ static int journal_get_superblock(journal_t *journal)
 		goto out;
 	}
 
+	if (JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM) &&
+	    JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+		/* Can't have checksum v1 and v2 on at the same time! */
+		printk(KERN_ERR "JBD: Can't enable checksumming v1 and v2 "
+		       "at the same time!\n");
+		goto out;
+	}
+
+	if (!jbd2_verify_csum_type(journal, sb)) {
+		printk(KERN_ERR "JBD: Unknown checksum type\n");
+		goto out;
+	}
+
+	/* Load the checksum driver */
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+		journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+		if (IS_ERR(journal->j_chksum_driver)) {
+			printk(KERN_ERR "JBD: Cannot load crc32c driver.\n");
+			err = PTR_ERR(journal->j_chksum_driver);
+			journal->j_chksum_driver = NULL;
+			goto out;
+		}
+	}
+
+	/* Check superblock checksum */
+	if (!jbd2_superblock_csum_verify(journal, sb)) {
+		printk(KERN_ERR "JBD: journal checksum error\n");
+		goto out;
+	}
+
+	/* Precompute checksum seed for all metadata */
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
+						   sizeof(sb->s_uuid));
+
+	set_buffer_verified(bh);
+
 	return 0;
 
 out:
@@ -1564,6 +1642,8 @@ int jbd2_journal_destroy(journal_t *journal)
 		iput(journal->j_inode);
 	if (journal->j_revoke)
 		jbd2_journal_destroy_revoke(journal);
+	if (journal->j_chksum_driver)
+		crypto_free_shash(journal->j_chksum_driver);
 	kfree(journal->j_wbuf);
 	kfree(journal);
 
@@ -1653,6 +1733,10 @@ int jbd2_journal_check_available_features (journal_t *journal, unsigned long com
 int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 			  unsigned long ro, unsigned long incompat)
 {
+#define INCOMPAT_FEATURE_ON(f) \
+		((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
+#define COMPAT_FEATURE_ON(f) \
+		((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
 	journal_superblock_t *sb;
 
 	if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
@@ -1661,16 +1745,54 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 	if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
 		return 0;
 
+	/* Asking for checksumming v2 and v1?  Only give them v2. */
+	if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2 &&
+	    compat & JBD2_FEATURE_COMPAT_CHECKSUM)
+		compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
+
 	jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
 		  compat, ro, incompat);
 
 	sb = journal->j_superblock;
 
+	/* If enabling v2 checksums, update superblock */
+	if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+		sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
+		sb->s_feature_compat &=
+			~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
+
+		/* Load the checksum driver */
+		if (journal->j_chksum_driver == NULL) {
+			journal->j_chksum_driver = crypto_alloc_shash("crc32c",
+								      0, 0);
+			if (IS_ERR(journal->j_chksum_driver)) {
+				printk(KERN_ERR "JBD: Cannot load crc32c "
+				       "driver.\n");
+				journal->j_chksum_driver = NULL;
+				return 0;
+			}
+		}
+
+		/* Precompute checksum seed for all metadata */
+		if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+					      JBD2_FEATURE_INCOMPAT_CSUM_V2))
+			journal->j_csum_seed = jbd2_chksum(journal, ~0,
+							   sb->s_uuid,
+							   sizeof(sb->s_uuid));
+	}
+
+	/* If enabling v1 checksums, downgrade superblock */
+	if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
+		sb->s_feature_incompat &=
+			~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2);
+
 	sb->s_feature_compat    |= cpu_to_be32(compat);
 	sb->s_feature_ro_compat |= cpu_to_be32(ro);
 	sb->s_feature_incompat  |= cpu_to_be32(incompat);
 
 	return 1;
+#undef COMPAT_FEATURE_ON
+#undef INCOMPAT_FEATURE_ON
 }
 
 /*
@@ -1975,10 +2097,16 @@ int jbd2_journal_blocks_per_page(struct inode *inode)
  */
 size_t journal_tag_bytes(journal_t *journal)
 {
+	journal_block_tag_t tag;
+	size_t x = 0;
+
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		x += sizeof(tag.t_checksum);
+
 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-		return JBD2_TAG_SIZE64;
+		return x + JBD2_TAG_SIZE64;
 	else
-		return JBD2_TAG_SIZE32;
+		return x + JBD2_TAG_SIZE32;
 }
 
 /*

fs/jbd2/recovery.c

@@ -174,6 +174,25 @@ static int jread(struct buffer_head **bhp, journal_t *journal,
 	return 0;
 }
 
+static int jbd2_descr_block_csum_verify(journal_t *j,
+					void *buf)
+{
+	struct jbd2_journal_block_tail *tail;
+	__u32 provided, calculated;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
+			sizeof(struct jbd2_journal_block_tail));
+	provided = tail->t_checksum;
+	tail->t_checksum = 0;
+	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
+	tail->t_checksum = provided;
+
+	provided = be32_to_cpu(provided);
+	return provided == calculated;
+}
 
 /*
  * Count the number of in-use tags in a journal descriptor block.
@@ -186,6 +205,9 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
 	int			nr = 0, size = journal->j_blocksize;
 	int			tag_bytes = journal_tag_bytes(journal);
 
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		size -= sizeof(struct jbd2_journal_block_tail);
+
 	tagp = &bh->b_data[sizeof(journal_header_t)];
 
 	while ((tagp - bh->b_data + tag_bytes) <= size) {
@@ -193,10 +215,10 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
 
 		nr++;
 		tagp += tag_bytes;
-		if (!(tag->t_flags & cpu_to_be32(JBD2_FLAG_SAME_UUID)))
+		if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
 			tagp += 16;
 
-		if (tag->t_flags & cpu_to_be32(JBD2_FLAG_LAST_TAG))
+		if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
 			break;
 	}
 
@@ -353,6 +375,41 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh,
 	return 0;
 }
 
+static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
+{
+	struct commit_header *h;
+	__u32 provided, calculated;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	h = buf;
+	provided = h->h_chksum[0];
+	h->h_chksum[0] = 0;
+	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
+	h->h_chksum[0] = provided;
+
+	provided = be32_to_cpu(provided);
+	return provided == calculated;
+}
+
+static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
+				      void *buf, __u32 sequence)
+{
+	__u32 provided, calculated;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	sequence = cpu_to_be32(sequence);
+	calculated = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
+				 sizeof(sequence));
+	calculated = jbd2_chksum(j, calculated, buf, j->j_blocksize);
+	provided = be32_to_cpu(tag->t_checksum);
+
+	return provided == cpu_to_be32(calculated);
+}
+
 static int do_one_pass(journal_t *journal,
 			struct recovery_info *info, enum passtype pass)
 {
@@ -366,6 +423,7 @@ static int do_one_pass(journal_t *journal,
 	int			blocktype;
 	int			tag_bytes = journal_tag_bytes(journal);
 	__u32			crc32_sum = ~0; /* Transactional Checksums */
+	int			descr_csum_size = 0;
 
 	/*
 	 * First thing is to establish what we expect to find in the log
@@ -451,6 +509,18 @@ static int do_one_pass(journal_t *journal,
 
 		switch(blocktype) {
 		case JBD2_DESCRIPTOR_BLOCK:
+			/* Verify checksum first */
+			if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+					JBD2_FEATURE_INCOMPAT_CSUM_V2))
+				descr_csum_size =
+					sizeof(struct jbd2_journal_block_tail);
+			if (descr_csum_size > 0 &&
+			    !jbd2_descr_block_csum_verify(journal,
+							  bh->b_data)) {
+				err = -EIO;
+				goto failed;
+			}
+
 			/* If it is a valid descriptor block, replay it
 			 * in pass REPLAY; if journal_checksums enabled, then
 			 * calculate checksums in PASS_SCAN, otherwise,
@@ -481,11 +551,11 @@ static int do_one_pass(journal_t *journal,
 
 			tagp = &bh->b_data[sizeof(journal_header_t)];
 			while ((tagp - bh->b_data + tag_bytes)
-			       <= journal->j_blocksize) {
+			       <= journal->j_blocksize - descr_csum_size) {
 				unsigned long io_block;
 
 				tag = (journal_block_tag_t *) tagp;
-				flags = be32_to_cpu(tag->t_flags);
+				flags = be16_to_cpu(tag->t_flags);
 
 				io_block = next_log_block++;
 				wrap(journal, next_log_block);
@@ -516,6 +586,19 @@ static int do_one_pass(journal_t *journal,
 						goto skip_write;
 					}
 
+					/* Look for block corruption */
+					if (!jbd2_block_tag_csum_verify(
+						journal, tag, obh->b_data,
+						be32_to_cpu(tmp->h_sequence))) {
+						brelse(obh);
+						success = -EIO;
+						printk(KERN_ERR "JBD: Invalid "
+						       "checksum recovering "
+						       "block %llu in log\n",
+						       blocknr);
+						continue;
+					}
+
 					/* Find a buffer for the new
 					 * data being restored */
 					nbh = __getblk(journal->j_fs_dev,
@@ -650,6 +733,19 @@ static int do_one_pass(journal_t *journal,
 				}
 				crc32_sum = ~0;
 			}
+			if (pass == PASS_SCAN &&
+			    !jbd2_commit_block_csum_verify(journal,
+							   bh->b_data)) {
+				info->end_transaction = next_commit_ID;
+
+				if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
+				     JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
+					journal->j_failed_commit =
+						next_commit_ID;
+					brelse(bh);
+					break;
+				}
+			}
 			brelse(bh);
 			next_commit_ID++;
 			continue;
@@ -706,6 +802,25 @@ static int do_one_pass(journal_t *journal,
 	return err;
 }
 
+static int jbd2_revoke_block_csum_verify(journal_t *j,
+					 void *buf)
+{
+	struct jbd2_journal_revoke_tail *tail;
+	__u32 provided, calculated;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
+			sizeof(struct jbd2_journal_revoke_tail));
+	provided = tail->r_checksum;
+	tail->r_checksum = 0;
+	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
+	tail->r_checksum = provided;
+
+	provided = be32_to_cpu(provided);
+	return provided == calculated;
+}
 
 /* Scan a revoke record, marking all blocks mentioned as revoked. */
 
@@ -720,6 +835,9 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
 	offset = sizeof(jbd2_journal_revoke_header_t);
 	max = be32_to_cpu(header->r_count);
 
+	if (!jbd2_revoke_block_csum_verify(journal, header))
+		return -EINVAL;
+
 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
 		record_len = 8;
 

fs/jbd2/revoke.c

@@ -578,6 +578,7 @@ static void write_one_revoke_record(journal_t *journal,
 				    struct jbd2_revoke_record_s *record,
 				    int write_op)
 {
+	int csum_size = 0;
 	struct journal_head *descriptor;
 	int offset;
 	journal_header_t *header;
@@ -592,9 +593,13 @@ static void write_one_revoke_record(journal_t *journal,
 	descriptor = *descriptorp;
 	offset = *offsetp;
 
+	/* Do we need to leave space at the end for a checksum? */
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		csum_size = sizeof(struct jbd2_journal_revoke_tail);
+
 	/* Make sure we have a descriptor with space left for the record */
 	if (descriptor) {
-		if (offset == journal->j_blocksize) {
+		if (offset >= journal->j_blocksize - csum_size) {
 			flush_descriptor(journal, descriptor, offset, write_op);
 			descriptor = NULL;
 		}
@@ -631,6 +636,24 @@ static void write_one_revoke_record(journal_t *journal,
 	*offsetp = offset;
 }
 
+static void jbd2_revoke_csum_set(journal_t *j,
+				 struct journal_head *descriptor)
+{
+	struct jbd2_journal_revoke_tail *tail;
+	__u32 csum;
+
+	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+		return;
+
+	tail = (struct jbd2_journal_revoke_tail *)
+			(jh2bh(descriptor)->b_data + j->j_blocksize -
+			sizeof(struct jbd2_journal_revoke_tail));
+	tail->r_checksum = 0;
+	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
+			   j->j_blocksize);
+	tail->r_checksum = cpu_to_be32(csum);
+}
+
 /*
  * Flush a revoke descriptor out to the journal.  If we are aborting,
  * this is a noop; otherwise we are generating a buffer which needs to
@@ -652,6 +675,8 @@ static void flush_descriptor(journal_t *journal,
 
 	header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
 	header->r_count = cpu_to_be32(offset);
+	jbd2_revoke_csum_set(journal, descriptor);
+
 	set_buffer_jwrite(bh);
 	BUFFER_TRACE(bh, "write");
 	set_buffer_dirty(bh);

fs/jbd2/transaction.c

@@ -162,8 +162,8 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
 
 alloc_transaction:
 	if (!journal->j_running_transaction) {
-		new_transaction = kmem_cache_alloc(transaction_cache,
-						   gfp_mask | __GFP_ZERO);
+		new_transaction = kmem_cache_zalloc(transaction_cache,
+						    gfp_mask);
 		if (!new_transaction) {
 			/*
 			 * If __GFP_FS is not present, then we may be

include/linux/jbd2.h

@@ -31,6 +31,7 @@
 #include <linux/mutex.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
+#include <crypto/hash.h>
 #endif
 
 #define journal_oom_retry 1
@@ -147,12 +148,24 @@ typedef struct journal_header_s
 #define JBD2_CRC32_CHKSUM   1
 #define JBD2_MD5_CHKSUM     2
 #define JBD2_SHA1_CHKSUM    3
+#define JBD2_CRC32C_CHKSUM  4
 
 #define JBD2_CRC32_CHKSUM_SIZE 4
 
 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
 /*
  * Commit block header for storing transactional checksums:
+ *
+ * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
+ * fields are used to store a checksum of the descriptor and data blocks.
+ *
+ * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
+ * field is used to store crc32c(uuid+commit_block).  Each journal metadata
+ * block gets its own checksum, and data block checksums are stored in
+ * journal_block_tag (in the descriptor).  The other h_chksum* fields are
+ * not used.
+ *
+ * Checksum v1 and v2 are mutually exclusive features.
  */
 struct commit_header {
 	__be32		h_magic;
@@ -175,13 +188,19 @@ struct commit_header {
 typedef struct journal_block_tag_s
 {
 	__be32		t_blocknr;	/* The on-disk block number */
-	__be32		t_flags;	/* See below */
+	__be16		t_checksum;	/* truncated crc32c(uuid+seq+block) */
+	__be16		t_flags;	/* See below */
 	__be32		t_blocknr_high; /* most-significant high 32bits. */
 } journal_block_tag_t;
 
 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high))
 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t))
 
+/* Tail of descriptor block, for checksumming */
+struct jbd2_journal_block_tail {
+	__be32		t_checksum;	/* crc32c(uuid+descr_block) */
+};
+
 /*
  * The revoke descriptor: used on disk to describe a series of blocks to
  * be revoked from the log
@@ -192,6 +211,10 @@ typedef struct jbd2_journal_revoke_header_s
 	__be32		 r_count;	/* Count of bytes used in the block */
 } jbd2_journal_revoke_header_t;
 
+/* Tail of revoke block, for checksumming */
+struct jbd2_journal_revoke_tail {
+	__be32		r_checksum;	/* crc32c(uuid+revoke_block) */
+};
 
 /* Definitions for the journal tag flags word: */
 #define JBD2_FLAG_ESCAPE		1	/* on-disk block is escaped */
@@ -241,7 +264,10 @@ typedef struct journal_superblock_s
 	__be32	s_max_trans_data;	/* Limit of data blocks per trans. */
 
 /* 0x0050 */
-	__u32	s_padding[44];
+	__u8	s_checksum_type;	/* checksum type */
+	__u8	s_padding2[3];
+	__u32	s_padding[42];
+	__be32	s_checksum;		/* crc32c(superblock) */
 
 /* 0x0100 */
 	__u8	s_users[16*48];		/* ids of all fs'es sharing the log */
@@ -263,13 +289,15 @@ typedef struct journal_superblock_s
 #define JBD2_FEATURE_INCOMPAT_REVOKE		0x00000001
 #define JBD2_FEATURE_INCOMPAT_64BIT		0x00000002
 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT	0x00000004
+#define JBD2_FEATURE_INCOMPAT_CSUM_V2		0x00000008
 
 /* Features known to this kernel version: */
 #define JBD2_KNOWN_COMPAT_FEATURES	JBD2_FEATURE_COMPAT_CHECKSUM
 #define JBD2_KNOWN_ROCOMPAT_FEATURES	0
 #define JBD2_KNOWN_INCOMPAT_FEATURES	(JBD2_FEATURE_INCOMPAT_REVOKE | \
 					JBD2_FEATURE_INCOMPAT_64BIT | \
-					JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)
+					JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
+					JBD2_FEATURE_INCOMPAT_CSUM_V2)
 
 #ifdef __KERNEL__
 
@@ -939,6 +967,12 @@ struct journal_s
 	 * superblock pointer here
 	 */
 	void *j_private;
+
+	/* Reference to checksum algorithm driver via cryptoapi */
+	struct crypto_shash *j_chksum_driver;
+
+	/* Precomputed journal UUID checksum for seeding other checksums */
+	__u32 j_csum_seed;
 };
 
 /*
@@ -1268,6 +1302,25 @@ static inline int jbd_space_needed(journal_t *journal)
 
 extern int jbd_blocks_per_page(struct inode *inode);
 
+static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
+			      const void *address, unsigned int length)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(journal->j_chksum_driver)];
+	} desc;
+	int err;
+
+	desc.shash.tfm = journal->j_chksum_driver;
+	desc.shash.flags = 0;
+	*(u32 *)desc.ctx = crc;
+
+	err = crypto_shash_update(&desc.shash, address, length);
+	BUG_ON(err);
+
+	return *(u32 *)desc.ctx;
+}
+
 #ifdef __KERNEL__
 
 #define buffer_trace_init(bh)	do {} while (0)

include/linux/jbd_common.h

@@ -12,6 +12,7 @@ enum jbd_state_bits {
 	BH_State,		/* Pins most journal_head state */
 	BH_JournalHead,		/* Pins bh->b_private and jh->b_bh */
 	BH_Unshadow,		/* Dummy bit, for BJ_Shadow wakeup filtering */
+	BH_Verified,		/* Metadata block has been verified ok */
 	BH_JBDPrivateStart,	/* First bit available for private use by FS */
 };
 
@@ -24,6 +25,7 @@ TAS_BUFFER_FNS(Revoked, revoked)
 BUFFER_FNS(RevokeValid, revokevalid)
 TAS_BUFFER_FNS(RevokeValid, revokevalid)
 BUFFER_FNS(Freed, freed)
+BUFFER_FNS(Verified, verified)
 
 static inline struct buffer_head *jh2bh(struct journal_head *jh)
 {