3  *  linux/fs/ext4/indirect.c
35 } Indirect;  typedef
37 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)  in add_chain()
49  *	       followed (on disk) by an indirect block.
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
66  * indirect block) is spelled differently, because otherwise on an
115  *	ext4_get_branch - read the chain of indirect blocks leading to data
118  *	@offsets: offsets of pointers in inode/indirect blocks
128  *	for i>0) and chain[i].bh points to the buffer_head of i-th indirect
136  *	or when it gets an IO error reading an indirect block
138  *	or when it reads all @depth-1 indirect blocks successfully and finds
144 static Indirect *ext4_get_branch(struct inode *inode, int depth,  in ext4_get_branch()
146 				 Indirect chain[4], int *err)  in ext4_get_branch()
149 	Indirect *p = chain;  in ext4_get_branch()
200  *	@ind: descriptor of indirect block.
206  *	  + if pointer will live in indirect block - allocate near that block.
217 static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)  in ext4_find_near()
229 	/* No such thing, so let's try location of indirect block */  in ext4_find_near()
252 				   Indirect *partial)  in ext4_find_goal()
269  *	@branch: chain of indirect blocks
270  *	@k: number of blocks need for indirect blocks
272  *	@blocks_to_boundary:  the offset in the indirect block
275  *	direct and indirect blocks.
277 static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,  in ext4_blks_to_allocate()
283 	 * Simple case, [t,d]Indirect block(s) has not allocated yet  in ext4_blks_to_allocate()
307  * @indirect_blks: number of allocated indirect blocks
331 			     Indirect *branch)  in ext4_alloc_branch()
399 		 * We want to ext4_forget() only freshly allocated indirect  in ext4_alloc_branch()
401 		 * (buffer at branch[0].bh is indirect block / inode already  in ext4_alloc_branch()
419  * @num:   number of indirect blocks we are adding
427 			      Indirect *where, int num)  in ext4_splice_branch()
434 	 * If we're splicing into a [td]indirect block (as opposed to the  in ext4_splice_branch()
435 	 * inode) then we need to get write access to the [td]indirect block  in ext4_splice_branch()
460 	/* had we spliced it onto indirect block? */  in ext4_splice_branch()
463 		 * If we spliced it onto an indirect block, we haven't  in ext4_splice_branch()
465 		 * onto an indirect block at the very end of the file (the  in ext4_splice_branch()
470 		ext4_debug("splicing indirect only\n");  in ext4_splice_branch()
504  * (i.e., using the traditional indirect/double-indirect i_blocks
537 	Indirect chain[4];  in ext4_ind_map_blocks()
538 	Indirect *partial;  in ext4_ind_map_blocks()
595 	/* Failed read of indirect block */  in ext4_ind_map_blocks()
622 	/* the number of blocks need to allocate for [d,t]indirect blocks */  in ext4_ind_map_blocks()
626 	 * Next look up the indirect map to count the totoal number of  in ext4_ind_map_blocks()
683  * Calculate number of indirect blocks touched by mapping @nrblocks logically
690 	 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,  in ext4_ind_trans_blocks()
770  *	ext4_find_shared - find the indirect blocks for partial truncation.
774  *	@chain:	  place to store the pointers to partial indirect blocks
780  *	indirect blocks but leave the blocks themselves alive. Block is
804 static Indirect *ext4_find_shared(struct inode *inode, int depth,  in ext4_find_shared()
805 				  ext4_lblk_t offsets[4], Indirect chain[4],  in ext4_find_shared()
808 	Indirect *partial, *p;  in ext4_find_shared()
854  * Zero a number of block pointers in either an inode or an indirect block.
856  * indirect block for further modification.
906  * @this_bh:	indirect buffer_head which contains *@first and *@last
935 	if (this_bh) {				/* For indirect block */  in ext4_free_data()
939 		/* Important: if we can't update the indirect pointers  in ext4_free_data()
980 		 * point. However, if the data is corrupted and an indirect  in ext4_free_data()
988 					 "circular indirect block detected at "  in ext4_free_data()
1028 						 "invalid indirect mapped "  in ext4_free_branches()
1059 			 * We want the freeing of this indirect block to be  in ext4_free_branches()
1085 			 * indirect block if it gets reallocated as a  in ext4_free_branches()
1097 				 * pointed to by an indirect block: journal it  in ext4_free_branches()
1125 	Indirect chain[4];  in ext4_ind_truncate()
1126 	Indirect *partial;  in ext4_ind_truncate()
1157 		 * equal to the indirect block limit.  in ext4_ind_truncate()
1179 			/* Shared branch grows from an indirect block */  in ext4_ind_truncate()
1186 	/* Clear the ends of indirect blocks on the shared branch */  in ext4_ind_truncate()
1241 	Indirect chain[4], chain2[4];  in ext4_ind_remove_space()
1242 	Indirect *partial, *partial2;  in ext4_ind_remove_space()
1243 	Indirect *p = NULL, *p2 = NULL;  in ext4_ind_remove_space()
1293 				/* Shared branch grows from an indirect block */  in ext4_ind_remove_space()
1302 		 * Clear the ends of indirect blocks on the shared branch  in ext4_ind_remove_space()
1327 			 * ext4_find_shared returns Indirect structure which  in ext4_ind_remove_space()
1336 		 * Clear the ends of indirect blocks on the shared branch  in ext4_ind_remove_space()
1374 				/* Shared branch grows from an indirect block */  in ext4_ind_remove_space()
1386 		 * ext4_find_shared returns Indirect structure which  in ext4_ind_remove_space()