diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 7bfbd58..7266247 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -25,6 +25,8 @@ if (IS_ERR(path)) { \ ret = PTR_ERR(path); \ path = NULL; \ + } else if (path[ext_depth(inode)].p_ext == NULL) { \ + ret = -ENODATA; \ } \ } while (0) @@ -284,7 +286,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, if (new_flag) { get_ext_path(orig_path, orig_inode, eblock, err); - if (orig_path == NULL) + if (err) goto out; if (ext4_ext_insert_extent(handle, orig_inode, @@ -295,7 +297,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, if (end_flag) { get_ext_path(orig_path, orig_inode, le32_to_cpu(end_ext->ee_block) - 1, err); - if (orig_path == NULL) + if (err) goto out; if (ext4_ext_insert_extent(handle, orig_inode, @@ -554,8 +556,10 @@ mext_leaf_block(handle_t *handle, struct inode *orig_inode, * @orig_off: block offset of original inode * @donor_off: block offset of donor inode * @max_count: the maximun length of extents + * + * Return 0 on success, or a negative error value on failure. */ -static void +static int mext_calc_swap_extents(struct ext4_extent *tmp_dext, struct ext4_extent *tmp_oext, ext4_lblk_t orig_off, ext4_lblk_t donor_off, @@ -564,6 +568,19 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, ext4_lblk_t diff, orig_diff; struct ext4_extent dext_old, oext_old; + BUG_ON(orig_off != donor_off); + + /* original and donor extents have to cover the same block offset */ + if (orig_off < le32_to_cpu(tmp_oext->ee_block) || + le32_to_cpu(tmp_oext->ee_block) + + ext4_ext_get_actual_len(tmp_oext) - 1 < orig_off) + return -ENODATA; + + if (orig_off < le32_to_cpu(tmp_dext->ee_block) || + le32_to_cpu(tmp_dext->ee_block) + + ext4_ext_get_actual_len(tmp_dext) - 1 < orig_off) + return -ENODATA; + dext_old = *tmp_dext; oext_old = *tmp_oext; @@ -591,6 +608,8 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, copy_extent_status(&oext_old, tmp_dext); copy_extent_status(&dext_old, tmp_oext); + + return 0; } /** @@ -632,12 +651,12 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, /* Get the original extent for the block "orig_off" */ get_ext_path(orig_path, orig_inode, orig_off, err); - if (orig_path == NULL) + if (err) goto out; /* Get the donor extent for the head */ get_ext_path(donor_path, donor_inode, donor_off, err); - if (donor_path == NULL) + if (err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; @@ -647,8 +666,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, dext = donor_path[depth].p_ext; tmp_dext = *dext; - mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, + err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, donor_off, count); + if (err) + goto out; /* Loop for the donor extents */ while (1) { @@ -679,7 +700,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, if (orig_path) ext4_ext_drop_refs(orig_path); get_ext_path(orig_path, orig_inode, orig_off, err); - if (orig_path == NULL) + if (err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; @@ -694,7 +715,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, ext4_ext_drop_refs(donor_path); get_ext_path(donor_path, donor_inode, donor_off, err); - if (donor_path == NULL) + if (err) goto out; depth = ext_depth(donor_inode); dext = donor_path[depth].p_ext; @@ -705,9 +726,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, } tmp_dext = *dext; - mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, - donor_off, - count - replaced_count); + err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, + donor_off, count - replaced_count); + if (err) + goto out; } out: @@ -1156,27 +1178,27 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, len -= block_end - file_end; get_ext_path(orig_path, orig_inode, block_start, ret); - if (orig_path == NULL) + if (ret) goto out2; /* Get path structure to check the hole */ get_ext_path(holecheck_path, orig_inode, block_start, ret); - if (holecheck_path == NULL) + if (ret) goto out; depth = ext_depth(orig_inode); ext_cur = holecheck_path[depth].p_ext; - if (ext_cur == NULL) { - ret = -EINVAL; - goto out; - } /* - * Get proper extent whose ee_block is beyond block_start - * if block_start was within the hole. + * Get proper starting location of block replacement if block_start was + * within the hole. */ if (le32_to_cpu(ext_cur->ee_block) + ext4_ext_get_actual_len(ext_cur) - 1 < block_start) { + /* + * The hole exists between extents or the tail of + * original file. + */ last_extent = mext_next_extent(orig_inode, holecheck_path, &ext_cur); if (last_extent < 0) { @@ -1189,8 +1211,12 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, ret = last_extent; goto out; } - } - seq_start = block_start; + seq_start = le32_to_cpu(ext_cur->ee_block); + } else if (le32_to_cpu(ext_cur->ee_block) > block_start) + /* The hole exists at the beginning of original file. */ + seq_start = le32_to_cpu(ext_cur->ee_block); + else + seq_start = block_start; /* No blocks within the specified range. */ if (le32_to_cpu(ext_cur->ee_block) > block_end) { @@ -1292,7 +1318,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, ext4_ext_drop_refs(holecheck_path); get_ext_path(holecheck_path, orig_inode, seq_start, ret); - if (holecheck_path == NULL) + if (ret) break; depth = holecheck_path->p_depth; @@ -1300,7 +1326,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, if (orig_path) ext4_ext_drop_refs(orig_path); get_ext_path(orig_path, orig_inode, seq_start, ret); - if (orig_path == NULL) + if (ret) break; ext_cur = holecheck_path[depth].p_ext;