diff options
| -rw-r--r-- | fs/ext4/indirect.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index c32802c956d5..bf7fa1507e81 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -561,10 +561,16 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode, unsigned epb = inode->i_sb->s_blocksize / sizeof(u32); int i; - /* Count number blocks in a subtree under 'partial' */ - count = 1; - for (i = 0; partial + i != chain + depth - 1; i++) - count *= epb; + /* + * Count number blocks in a subtree under 'partial'. At each + * level we count number of complete empty subtrees beyond + * current offset and then descend into the subtree only + * partially beyond current offset. + */ + count = 0; + for (i = partial - chain + 1; i < depth; i++) + count = count * epb + (epb - offsets[i] - 1); + count++; /* Fill in size of a hole we found */ map->m_pblk = 0; map->m_len = min_t(unsigned int, map->m_len, count); |