1 // SPDX-License-Identifier: GPL-2.0
14 	p->key = *(p->p = v);  in add_chain()
15 	p->bh = bh;  in add_chain()
20 	while (from <= to && from->key == *from->p)  in verify_chain()
27 	return (block_t *)((char*)bh->b_data + bh->b_size);  in block_end()
31 					int depth,  in get_branch()  argument
33 					Indirect chain[DEPTH],  in get_branch()  argument
36 	struct super_block *sb = inode->i_sb;  in get_branch()
43 	if (!p->key)  in get_branch()
45 	while (--depth) {  in get_branch()
46 		bh = sb_bread(sb, block_to_cpu(p->key));  in get_branch()
52 		add_chain(++p, bh, (block_t *)bh->b_data + *++offsets);  in get_branch()
54 		if (!p->key)  in get_branch()
62 	*err = -EAGAIN;  in get_branch()
65 	*err = -EIO;  in get_branch()
78 	int err = -ENOSPC;  in alloc_branch()
88 		bh = sb_getblk(inode->i_sb, parent);  in alloc_branch()
91 			err = -ENOMEM;  in alloc_branch()
95 		memset(bh->b_data, 0, bh->b_size);  in alloc_branch()
97 		branch[n].p = (block_t*) bh->b_data + offsets[n];  in alloc_branch()
116 				     Indirect chain[DEPTH],  in splice_branch()  argument
125 	if (!verify_chain(chain, where-1) || *where->p)  in splice_branch()
128 	*where->p = where->key;  in splice_branch()
134 	inode->i_ctime = current_time(inode);  in splice_branch()
137 	if (where->bh)  in splice_branch()
138 		mark_buffer_dirty_inode(where->bh, inode);  in splice_branch()
149 	return -EAGAIN;  in splice_branch()
155 	int err = -EIO;  in get_block()
156 	int offsets[DEPTH];  in get_block()
157 	Indirect chain[DEPTH];  in get_block()
160 	int depth = block_to_path(inode, block, offsets);  in get_block()  local
162 	if (depth == 0)  in get_block()
166 	partial = get_branch(inode, depth, offsets, chain, &err);  in get_block()
168 	/* Simplest case - block found, no allocation needed */  in get_block()
171 		map_bh(bh, inode->i_sb, block_to_cpu(chain[depth-1].key));  in get_block()
173 		partial = chain+depth-1; /* the whole chain */  in get_block()
177 	/* Next simple case - plain lookup or failed read of indirect block */  in get_block()
178 	if (!create || err == -EIO) {  in get_block()
181 			brelse(partial->bh);  in get_block()
182 			partial--;  in get_block()
193 	if (err == -EAGAIN)  in get_block()
196 	left = (chain + depth) - partial;  in get_block()
197 	err = alloc_branch(inode, left, offsets+(partial-chain), partial);  in get_block()
209 		brelse(partial->bh);  in get_block()
210 		partial--;  in get_block()
224 				int depth,  in find_shared()  argument
225 				int offsets[DEPTH],  in find_shared()  argument
226 				Indirect chain[DEPTH],  in find_shared()  argument
233 	for (k = depth; k > 1 && !offsets[k-1]; k--)  in find_shared()
239 		partial = chain + k-1;  in find_shared()
240 	if (!partial->key && *partial->p) {  in find_shared()
244 	for (p=partial;p>chain && all_zeroes((block_t*)p->bh->b_data,p->p);p--)  in find_shared()
246 	if (p == chain + k - 1 && p > chain) {  in find_shared()
247 		p->p--;  in find_shared()
249 		*top = *p->p;  in find_shared()
250 		*p->p = 0;  in find_shared()
256 		brelse(partial->bh);  in find_shared()
257 		partial--;  in find_shared()
276 static void free_branches(struct inode *inode, block_t *p, block_t *q, int depth)  in free_branches()  argument
281 	if (depth--) {  in free_branches()
287 			bh = sb_bread(inode->i_sb, nr);  in free_branches()
290 			free_branches(inode, (block_t*)bh->b_data,  in free_branches()
291 				      block_end(bh), depth);  in free_branches()
302 	struct super_block *sb = inode->i_sb;  in truncate()
304 	int offsets[DEPTH];  in truncate()
305 	Indirect chain[DEPTH];  in truncate()
312 	iblock = (inode->i_size + sb->s_blocksize -1) >> sb->s_blocksize_bits;  in truncate()
313 	block_truncate_page(inode->i_mapping, inode->i_size, get_block);  in truncate()
325 	first_whole = offsets[0] + 1 - DIRECT;  in truncate()
331 			mark_buffer_dirty_inode(partial->bh, inode);  in truncate()
332 		free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);  in truncate()
336 		free_branches(inode, partial->p + 1, block_end(partial->bh),  in truncate()
337 				(chain+n-1) - partial);  in truncate()
338 		mark_buffer_dirty_inode(partial->bh, inode);  in truncate()
339 		brelse (partial->bh);  in truncate()
340 		partial--;  in truncate()
344 	while (first_whole < DEPTH-1) {  in truncate()
353 	inode->i_mtime = inode->i_ctime = current_time(inode);  in truncate()
359 	int k = sb->s_blocksize_bits - 10;  in nblocks()
360 	unsigned blocks, res, direct = DIRECT, i = DEPTH;  in nblocks()
361 	blocks = (size + sb->s_blocksize - 1) >> (BLOCK_SIZE_BITS + k);  in nblocks()
363 	while (--i && blocks > direct) {  in nblocks()
364 		blocks -= direct;  in nblocks()
365 		blocks += sb->s_blocksize/sizeof(block_t) - 1;  in nblocks()
366 		blocks /= sb->s_blocksize/sizeof(block_t);  in nblocks()