1 files changed, 420 insertions, 30 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 349d7b3671c..5845cd97bf8 100644
--- a/fs/ext4/namei.c
+++ b/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,
@@ -1052,10 +1351,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
 struct dentry *ext4_get_parent(struct dentry *child)
 {
         __u32 ino;
-        static const struct qstr dotdot = {
-                .name = "..",
-                .len = 2,
-        };
+        static const struct qstr dotdot = QSTR_INIT("..", 2);
         struct ext4_dir_entry_2 * de;
         struct buffer_head *bh;
 
@@ -1159,8 +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);
@@ -1207,10 +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));
 
@@ -1221,10 +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);
@@ -1261,11 +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;
@@ -1298,11 +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);
         /*
@@ -1321,7 +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;
@@ -1342,6 +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;
@@ -1349,6 +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));
@@ -1369,7 +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);
@@ -1385,8 +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),
@@ -1411,8 +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) {
@@ -1448,11 +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;
@@ -1471,6 +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);
@@ -1487,7 +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)
@@ -1519,6 +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)
@@ -1586,7 +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);
@@ -1612,7 +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;
@@ -1644,12 +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)  {
@@ -1670,7 +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;
@@ -1812,9 +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;
 
@@ -1855,16 +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);
@@ -1914,6 +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 ||
@@ -1945,6 +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)) {
@@ -2013,7 +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;
@@ -2086,7 +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 =
@@ -2445,6 +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;
@@ -2475,7 +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;
@@ -2529,7 +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;