53  *	data blocks at leaves and indirect blocks in intermediate nodes.
60  *	we need to know is the capacity of indirect blocks (taken from the
68  * if our filesystem had 8Kb blocks. We might use long long, but that would
115  *	ext4_get_branch - read the chain of indirect blocks leading to data
118  *	@offsets: offsets of pointers in inode/indirect blocks
138  *	or when it reads all @depth-1 indirect blocks successfully and finds
260  *	of direct blocks need to be allocated for the given branch.
262  *	@branch: chain of indirect blocks
263  *	@k: number of blocks need for indirect blocks
264  *	@blks: number of data blocks to be mapped.
267  *	return the total number of blocks to be allocate, including the
268  *	direct and indirect blocks.
277 	 * then it's clear blocks on that path have not allocated  in ext4_blks_to_allocate()
297  * ext4_alloc_branch() - allocate and set up a chain of blocks
300  * @indirect_blks: number of allocated indirect blocks
301  * @offsets: offsets (in the blocks) to store the pointers to next.
304  *	This function allocates blocks, zeroes out all but the last one,
316  *	If allocation fails we free all blocks we've allocated (and forget
383 		 * blocks.  Buffer for new_blocks[i-1] is at branch[i].bh and  in ext4_alloc_branch()
401  * @num:   number of indirect blocks we are adding
432 	 * direct blocks blocks  in ext4_splice_branch()
488  * to tree, set linkage between the newborn blocks, write them if sync is
491  * removals - all blocks on the path are immune now) and possibly force the
494  * allocations is needed - we simply release blocks and do not touch anything
499  * return > 0, # of blocks mapped or allocated.
505  * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
507  * blocks.
539 		/*map more blocks*/  in ext4_ind_map_blocks()
559 		 * Count number blocks in a subtree under 'partial'. At each  in ext4_ind_map_blocks()
582 		EXT4_ERROR_INODE(inode, "Can't allocate blocks for "  in ext4_ind_map_blocks()
600 	/* the number of blocks need to allocate for [d,t]indirect blocks */  in ext4_ind_map_blocks()
605 	 * direct blocks to allocate for this branch.  in ext4_ind_map_blocks()
653  * Calculate the number of metadata blocks need to reserve
679  * Calculate number of indirect blocks touched by mapping @nrblocks logically
680  * contiguous blocks
685 	 * With N contiguous data blocks, we need at most  in ext4_ind_trans_blocks()
686 	 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,  in ext4_ind_trans_blocks()
687 	 * 2 dindirect blocks, and 1 tindirect block  in ext4_ind_trans_blocks()
729  *	ext4_find_shared - find the indirect blocks for partial truncation.
733  *	@chain:	  place to store the pointers to partial indirect blocks
739  *	indirect blocks but leave the blocks themselves alive. Block is
751  *	partially truncated blocks - in @chain[].bh and pointers to
817  * We release `count' blocks on disk, but (last - first) may be greater
842 				 "blocks %llu len %lu",  in ext4_clear_blocks()
880  * ext4_free_data - free a list of data blocks
887  * We are freeing all blocks referred from that array (numbers are stored as
890  * We accumulate contiguous runs of blocks to free.  Conveniently, if these
891  * blocks are contiguous then releasing them at one time will only affect one
892  * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
903 	unsigned long count = 0;	    /* Number of blocks in the run */  in ext4_free_data()
916 		 * to the blocks, we can't free them. */  in ext4_free_data()
924 			/* accumulate blocks to free if they're contiguous */  in ext4_free_data()
979  *	We are freeing all blocks referred from these branches (numbers are
1046 			 * rather than leaking blocks.  in ext4_free_branches()
1064 			 * transaction where the data blocks are  in ext4_free_branches()
1090 		BUFFER_TRACE(parent_bh, "free data blocks");  in ext4_free_branches()
1132 		 * It is unnecessary to free any data blocks if last_block is  in ext4_ind_truncate()
1136 	} else if (n == 1) {		/* direct blocks */  in ext4_ind_truncate()
1162 	/* Clear the ends of indirect blocks on the shared branch */  in ext4_ind_truncate()
1207  *	Free the blocks in the defined range (end is exclusive endpoint of
1278 		 * Clear the ends of indirect blocks on the shared branch  in ext4_ind_remove_space()
1312 		 * Clear the ends of indirect blocks on the shared branch  in ext4_ind_remove_space()