142  *	data blocks at leaves and indirect blocks in intermediate nodes.
149  *	we need to know is the capacity of indirect blocks (taken from the
157  * if our filesystem had 8Kb blocks. We might use long long, but that would
206  *	ext2_get_branch - read the chain of indirect blocks leading to data
209  *	@offsets: offsets of pointers in inode/indirect blocks
231  *	or when it reads all @depth-1 indirect blocks successfully and finds
351  *	of direct blocks need to be allocated for the given branch.
353  * 	@branch: chain of indirect blocks
354  *	@k: number of blocks need for indirect blocks
355  *	@blks: number of data blocks to be mapped.
358  *	return the number of direct blocks to allocate.
368 	 * then it's clear blocks on that path have not allocated  in ext2_blks_to_allocate()
388  * ext2_alloc_blocks: Allocate multiple blocks needed for a branch.
391  * @indirect_blks: The number of blocks needed to allocate for indirect blocks.
392  * @blks: The number of blocks need to allocate for direct blocks.
394  *	the indirect blocks(if needed) and the first direct block.
397  * Return: Number of blocks allocated.
410 	 * Here we try to allocate the requested multiple blocks at once,  in ext2_alloc_blocks()
412 	 * To build a branch, we should allocate blocks for  in ext2_alloc_blocks()
413 	 * the indirect blocks(if not allocated yet), and at least  in ext2_alloc_blocks()
415 	 * minimum number of blocks need to allocate(required)  in ext2_alloc_blocks()
421 		/* allocating blocks for indirect blocks and direct blocks */  in ext2_alloc_blocks()
427 		/* allocate blocks for indirect blocks */  in ext2_alloc_blocks()
440 	/* total number of blocks allocated for direct blocks */  in ext2_alloc_blocks()
453  *	ext2_alloc_branch - allocate and set up a chain of blocks.
455  *	@indirect_blks: depth of the chain (number of blocks to allocate)
456  *	@blks: number of allocated direct blocks
458  *	@offsets: offsets (in the blocks) to store the pointers to next.
461  *	This function allocates @num blocks, zeroes out all but the last one,
473  *	If allocation fails we free all blocks we've allocated (and forget
498 	 * metadata blocks and data blocks are allocated.  in ext2_alloc_branch()
522 			 * data blocks numbers  in ext2_alloc_branch()
554  * @num:   number of indirect blocks we are adding
555  * @blks:  number of direct blocks we are adding
577 	 * direct blocks blocks  in ext2_splice_branch()
609  * to tree, set linkage between the newborn blocks, write them if sync is
612  * removals - all blocks on the path are immune now) and possibly force the
615  * allocations is needed - we simply release blocks and do not touch anything
620  * return > 0, # of blocks mapped or allocated.
653 		/*map more blocks*/  in ext2_get_blocks()
723 	/* the number of blocks need to allocate for [d,t]indirect blocks */  in ext2_get_blocks()
727 	 * direct blocks to allocate for this branch.  in ext2_get_blocks()
744 		 * We must unmap blocks before zeroing so that writeback cannot  in ext2_get_blocks()
877 	 * Blocks allocated can be used by the buffered-io path.  in ext2_iomap_end()
1004  *	ext2_find_shared - find the indirect blocks for partial truncation.
1008  *	@chain:	  place to store the pointers to partial indirect blocks
1014  *	blocks but leave the blocks themselves alive. Block is partially
1025  *	truncated blocks - in @chain[].bh and pointers to their last elements
1087  *	ext2_free_data - free a list of data blocks
1092  *	We are freeing all blocks referred from that array (numbers are
1105 			/* accumulate blocks to free if they're contiguous */  in ext2_free_data()
1132  *	We are freeing all blocks referred from these branches (numbers are
1216 	/* Clear the ends of indirect blocks on the shared branch */  in __ext2_truncate_blocks()