1 // SPDX-License-Identifier: GPL-2.0+
3  * NILFS B-tree node cache
5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
15 #include <linux/backing-dev.h>
25  * nilfs_init_btnc_inode - initialize B-tree node cache inode
28  * nilfs_init_btnc_inode() sets up an inode for B-tree node cache.
34 	btnc_inode->i_mode = S_IFREG;  in nilfs_init_btnc_inode()
35 	ii->i_flags = 0;  in nilfs_init_btnc_inode()
36 	memset(&ii->i_bmap_data, 0, sizeof(struct nilfs_bmap));  in nilfs_init_btnc_inode()
37 	mapping_set_gfp_mask(btnc_inode->i_mapping, GFP_NOFS);  in nilfs_init_btnc_inode()
38 	btnc_inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;  in nilfs_init_btnc_inode()
43 	invalidate_mapping_pages(btnc, 0, -1);  in nilfs_btnode_cache_clear()
50 	struct inode *inode = btnc->host;  in nilfs_btnode_create_block()
55 		return ERR_PTR(-ENOMEM);  in nilfs_btnode_create_block()
60 		 * The block buffer at the specified new address was already  in nilfs_btnode_create_block()
61 		 * in use.  This can happen if it is a virtual block number  in nilfs_btnode_create_block()
64 		 * clearing of an abandoned b-tree node is missing somewhere).  in nilfs_btnode_create_block()
66 		nilfs_error(inode->i_sb,  in nilfs_btnode_create_block()
67 …   "state inconsistency probably due to duplicate use of b-tree node block address %llu (ino=%lu)",  in nilfs_btnode_create_block()
68 			    (unsigned long long)blocknr, inode->i_ino);  in nilfs_btnode_create_block()
71 	memset(bh->b_data, 0, i_blocksize(inode));  in nilfs_btnode_create_block()
72 	bh->b_blocknr = blocknr;  in nilfs_btnode_create_block()
76 	folio_unlock(bh->b_folio);  in nilfs_btnode_create_block()
77 	folio_put(bh->b_folio);  in nilfs_btnode_create_block()
81 	folio_unlock(bh->b_folio);  in nilfs_btnode_create_block()
82 	folio_put(bh->b_folio);  in nilfs_btnode_create_block()
84 	return ERR_PTR(-EIO);  in nilfs_btnode_create_block()
92 	struct inode *inode = btnc->host;  in nilfs_btnode_submit_block()
98 		return -ENOMEM;  in nilfs_btnode_submit_block()
100 	err = -EEXIST; /* internal code */  in nilfs_btnode_submit_block()
101 	folio = bh->b_folio;  in nilfs_btnode_submit_block()
108 		if (inode->i_ino != NILFS_DAT_INO) {  in nilfs_btnode_submit_block()
109 			struct the_nilfs *nilfs = inode->i_sb->s_fs_info;  in nilfs_btnode_submit_block()
111 			/* blocknr is a virtual block number */  in nilfs_btnode_submit_block()
112 			err = nilfs_dat_translate(nilfs->ns_dat, blocknr,  in nilfs_btnode_submit_block()
123 			err = -EBUSY; /* internal code */  in nilfs_btnode_submit_block()
132 		err = -EEXIST; /* internal code */  in nilfs_btnode_submit_block()
136 	bh->b_blocknr = pblocknr; /* set block address for read */  in nilfs_btnode_submit_block()
137 	bh->b_end_io = end_buffer_read_sync;  in nilfs_btnode_submit_block()
140 	bh->b_blocknr = blocknr; /* set back to the given block address */  in nilfs_btnode_submit_block()
153  * nilfs_btnode_delete - delete B-tree node buffer
162 	struct folio *folio = bh->b_folio;  in nilfs_btnode_delete()
163 	pgoff_t index = folio->index;  in nilfs_btnode_delete()
172 	mapping = folio->mapping;  in nilfs_btnode_delete()
181  * nilfs_btnode_prepare_change_key - prepare to change the search key of a
182  *                                   b-tree node block
183  * @btnc: page cache in which the b-tree node block is buffered
187  * b-tree node block of the old key given in the "oldkey" member of @ctxt to
189  * page cache @btnc.  Here, the key of the block is an index in units of
190  * blocks, and if the page and block sizes match, it matches the page index
191  * in the page cache.
193  * If the page size and block size match, this function attempts to move the
195  * the new index of the cache.  If this insertion fails or if the page size
196  * and block size are different, it falls back to a copy preparation using
197  * nilfs_btnode_create_block(), inserts a new block at the position
202  * than the page size.
206  * * %-EIO	- I/O error (metadata corruption).
207  * * %-ENOMEM	- Insufficient memory available.
213 	struct inode *inode = btnc->host;  in nilfs_btnode_prepare_change_key()
214 	__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;  in nilfs_btnode_prepare_change_key()
220 	obh = ctxt->bh;  in nilfs_btnode_prepare_change_key()
221 	ctxt->newbh = NULL;  in nilfs_btnode_prepare_change_key()
223 	if (inode->i_blkbits == PAGE_SHIFT) {  in nilfs_btnode_prepare_change_key()
224 		struct folio *ofolio = obh->b_folio;  in nilfs_btnode_prepare_change_key()
227 		/* BUG_ON(oldkey != obh->b_folio->index); */  in nilfs_btnode_prepare_change_key()
228 		if (unlikely(oldkey != ofolio->index))  in nilfs_btnode_prepare_change_key()
234 		xa_lock_irq(&btnc->i_pages);  in nilfs_btnode_prepare_change_key()
235 		err = __xa_insert(&btnc->i_pages, newkey, ofolio, GFP_NOFS);  in nilfs_btnode_prepare_change_key()
236 		xa_unlock_irq(&btnc->i_pages);  in nilfs_btnode_prepare_change_key()
238 		 * Note: folio->index will not change to newkey until  in nilfs_btnode_prepare_change_key()
245 		else if (err != -EBUSY)  in nilfs_btnode_prepare_change_key()
260 	ctxt->newbh = nbh;  in nilfs_btnode_prepare_change_key()
264 	folio_unlock(obh->b_folio);  in nilfs_btnode_prepare_change_key()
269  * nilfs_btnode_commit_change_key - commit the change of the search key of
270  *                                  a b-tree node block
271  * @btnc: page cache in which the b-tree node block is buffered
276  * block buffer is prepared in "newbh" of @ctxt (i.e., a full folio move),
278  * Otherwise, it copies the block data and inherited flag states of "oldbh"
279  * to "newbh" and clears the "oldbh" from the cache.  In either case, the
283  * not support folio sizes larger than the page size.
288 	struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh;  in nilfs_btnode_commit_change_key()
289 	__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;  in nilfs_btnode_commit_change_key()
296 		ofolio = obh->b_folio;  in nilfs_btnode_commit_change_key()
297 		if (unlikely(oldkey != ofolio->index))  in nilfs_btnode_commit_change_key()
304 		xa_lock_irq(&btnc->i_pages);  in nilfs_btnode_commit_change_key()
305 		__xa_erase(&btnc->i_pages, oldkey);  in nilfs_btnode_commit_change_key()
306 		__xa_set_mark(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY);  in nilfs_btnode_commit_change_key()
307 		xa_unlock_irq(&btnc->i_pages);  in nilfs_btnode_commit_change_key()
309 		ofolio->index = obh->b_blocknr = newkey;  in nilfs_btnode_commit_change_key()
315 		nbh->b_blocknr = newkey;  in nilfs_btnode_commit_change_key()
316 		ctxt->bh = nbh;  in nilfs_btnode_commit_change_key()
317 		nilfs_btnode_delete(obh); /* will decrement bh->b_count */  in nilfs_btnode_commit_change_key()
322  * nilfs_btnode_abort_change_key - abort the change of the search key of a
323  *                                 b-tree node block
324  * @btnc: page cache in which the b-tree node block is buffered
329  * any necessary cleanup.  If no valid block buffer is prepared in "newbh" of
331  * the move.  Otherwise, it clears "newbh" from the cache.
334  * not support folio sizes larger than the page size.
339 	struct buffer_head *nbh = ctxt->newbh;  in nilfs_btnode_abort_change_key()
340 	__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;  in nilfs_btnode_abort_change_key()
346 		xa_erase_irq(&btnc->i_pages, newkey);  in nilfs_btnode_abort_change_key()
347 		folio_unlock(ctxt->bh->b_folio);  in nilfs_btnode_abort_change_key()
351 		 * allocated to copy a node block to another location, use  in nilfs_btnode_abort_change_key()