Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...
[firefly-linux-kernel-4.4.55.git] / fs / ext4 / namei.c
index e2a3f4b0ff78d6f81fbf2228f12f201e6ab1a024..5845cd97bf8b094b0fc01082279e8d65ee73f241 100644 (file)
@@ -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;