Index: linux-4.18.0-147.0.3.el8/fs/ext4/namei.c =================================================================== --- linux-4.18.0-147.0.3.el8.orig/fs/ext4/namei.c +++ linux-4.18.0-147.0.3.el8/fs/ext4/namei.c @@ -198,22 +198,13 @@ struct dx_entry * hash version mod 4 should never be 0. Sincerely, the paranoia department. */ -struct dx_root +struct dx_root_info { - struct fake_dirent dot; - char dot_name[4]; - struct fake_dirent dotdot; - char dotdot_name[4]; - struct dx_root_info - { - __le32 reserved_zero; - u8 hash_version; - u8 info_length; /* 8 */ - u8 indirect_levels; - u8 unused_flags; - } - info; - struct dx_entry entries[0]; + __le32 reserved_zero; + u8 hash_version; + u8 info_length; /* 8 */ + u8 indirect_levels; + u8 unused_flags; }; struct dx_node @@ -514,6 +505,16 @@ ext4_next_entry(struct ext4_dir_entry_2 * Future: use high four bits of block for coalesce-on-delete flags * Mask them off for now. */ +struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de) +{ + /* get dotdot first */ + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1)); + + /* dx root info is after dotdot entry */ + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2)); + + return (struct dx_root_info *)de; +} static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) { @@ -738,7 +739,7 @@ dx_probe(struct ext4_filename *fname, st { unsigned count, indirect; struct dx_entry *at, *entries, *p, *q, *m; - struct dx_root *root; + struct dx_root_info *info; struct dx_frame *frame = frame_in; struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); u32 hash; @@ -747,18 +748,17 @@ dx_probe(struct ext4_filename *fname, st frame->bh = ext4_read_dirblock(dir, 0, INDEX); if (IS_ERR(frame->bh)) return (struct dx_frame *) frame->bh; - - root = (struct dx_root *) frame->bh->b_data; - if (root->info.hash_version != DX_HASH_TEA && - root->info.hash_version != DX_HASH_HALF_MD4 && - root->info.hash_version != DX_HASH_LEGACY) { - ext4_warning_inode(dir, "Unrecognised inode hash code %u for directory " - "%lu", root->info.hash_version, dir->i_ino); + info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data); + if (info->hash_version != DX_HASH_TEA && + info->hash_version != DX_HASH_HALF_MD4 && + info->hash_version != DX_HASH_LEGACY) { + ext4_warning(dir->i_sb, "Unrecognised inode hash code %d for directory " + "#%lu", info->hash_version, dir->i_ino); goto fail; } if (fname) hinfo = &fname->hinfo; - hinfo->hash_version = root->info.hash_version; + hinfo->hash_version = info->hash_version; if (hinfo->hash_version <= DX_HASH_TEA) hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; @@ -766,13 +766,13 @@ dx_probe(struct ext4_filename *fname, st ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo); hash = hinfo->hash; - if (root->info.unused_flags & 1) { + if (info->unused_flags & 1) { ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", - root->info.unused_flags); + info->unused_flags); goto fail; } - indirect = root->info.indirect_levels; + indirect = info->indirect_levels; if (indirect >= ext4_dir_htree_level(dir->i_sb)) { ext4_warning(dir->i_sb, "Directory (ino: %lu) htree depth %#06x exceed" @@ -785,14 +785,13 @@ dx_probe(struct ext4_filename *fname, st goto fail; } - entries = (struct dx_entry *)(((char *)&root->info) + - root->info.info_length); + entries = (struct dx_entry *)(((char *)info) + info->info_length); if (dx_get_limit(entries) != dx_root_limit(dir, - root->info.info_length)) { + info->info_length)) { ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", dx_get_limit(entries), - dx_root_limit(dir, root->info.info_length)); + dx_root_limit(dir, info->info_length)); goto fail; } @@ -877,7 +876,7 @@ static void dx_release(struct dx_frame * if (frames[0].bh == NULL) return; - info = &((struct dx_root *)frames[0].bh->b_data)->info; + info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data); /* save local copy, "info" may be freed after brelse() */ indirect_levels = info->indirect_levels; for (i = 0; i <= indirect_levels; i++) { @@ -1936,17 +1935,16 @@ static int make_indexed_dir(handle_t *ha struct inode *inode, struct buffer_head *bh) { struct buffer_head *bh2; - struct dx_root *root; struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; struct dx_entry *entries; - struct ext4_dir_entry_2 *de, *de2; + struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de; struct ext4_dir_entry_tail *t; char *data1, *top; unsigned len; int retval; unsigned blocksize; ext4_lblk_t block; - struct fake_dirent *fde; + struct dx_root_info *dx_info; int csum_size = 0; if (ext4_has_metadata_csum(inode->i_sb)) @@ -1961,18 +1959,19 @@ static int make_indexed_dir(handle_t *ha brelse(bh); return retval; } - root = (struct dx_root *) bh->b_data; + + dot_de = (struct ext4_dir_entry_2 *)bh->b_data; + dotdot_de = ext4_next_entry(dot_de, blocksize); /* The 0th block becomes the root, move the dirents out */ - fde = &root->dotdot; - de = (struct ext4_dir_entry_2 *)((char *)fde + - ext4_rec_len_from_disk(fde->rec_len, blocksize)); - if ((char *) de >= (((char *) root) + blocksize)) { + de = (struct ext4_dir_entry_2 *)((char *)dotdot_de + + ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize)); + if ((char *)de >= (((char *)dot_de) + blocksize)) { EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); brelse(bh); return -EFSCORRUPTED; } - len = ((char *) root) + (blocksize - csum_size) - (char *) de; + len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de; /* Allocate new block for the 0th block's dirents */ bh2 = ext4_append(handle, dir, &block); @@ -1998,19 +1997,24 @@ static int make_indexed_dir(handle_t *ha } /* 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), - blocksize); - memset (&root->info, 0, sizeof(root->info)); - root->info.info_length = sizeof(root->info); - root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; - entries = root->entries; + dotdot_de->rec_len = + ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len), + blocksize); + + /* initialize hashing info */ + dx_info = dx_get_dx_info(dot_de); + memset(dx_info, 0, sizeof(*dx_info)); + dx_info->info_length = sizeof(*dx_info); + dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; + + entries = (void *)dx_info + sizeof(*dx_info); + dx_set_block(entries, 1); dx_set_count(entries, 1); - dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); + dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info))); /* Initialize as for dx_probe */ - fname->hinfo.hash_version = root->info.hash_version; + fname->hinfo.hash_version = dx_info->hash_version; if (fname->hinfo.hash_version <= DX_HASH_TEA) fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; @@ -2352,7 +2356,7 @@ again: goto journal_error; } } else { - struct dx_root *dxroot; + struct dx_root_info *info; memcpy((char *) entries2, (char *) entries, icount * sizeof(struct dx_entry)); dx_set_limit(entries2, dx_node_limit(dir)); @@ -2360,8 +2364,9 @@ again: /* Set up root */ dx_set_count(entries, 1); dx_set_block(entries + 0, newblock); - dxroot = (struct dx_root *)frames[0].bh->b_data; - dxroot->info.indirect_levels += 1; + info = dx_get_dx_info((struct ext4_dir_entry_2 *) + frames[0].bh->b_data); + info->indirect_levels = 1; dxtrace(printk(KERN_DEBUG "Creating %d level index...\n", dxroot->info.indirect_levels));