Describe the Fourth Extended (ext4) File System Multiblock allocation feature.

What will be an ideal response?

Multiblock allocation - Block allocators decide which free blocks on a hard drive are used to write data. In ext3, only one 4-KB block could be allocated at a time, so the block allocator had to be called thousands of times just to write a small block of data. Ext4 can allocate multiple larger blocks in a single call.