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git.ipfire.org Git - people/ms/linux.git/blob - fs/nilfs2/btnode.c
1 // SPDX-License-Identifier: GPL-2.0+
3 * NILFS B-tree node cache
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
7 * Originally written by Seiji Kihara.
8 * Fully revised by Ryusuke Konishi for stabilization and simplification.
12 #include <linux/types.h>
13 #include <linux/buffer_head.h>
15 #include <linux/backing-dev.h>
16 #include <linux/gfp.h>
25 * nilfs_init_btnc_inode - initialize B-tree node cache inode
26 * @btnc_inode: inode to be initialized
28 * nilfs_init_btnc_inode() sets up an inode for B-tree node cache.
30 void nilfs_init_btnc_inode(struct inode
*btnc_inode
)
32 struct nilfs_inode_info
*ii
= NILFS_I(btnc_inode
);
34 btnc_inode
->i_mode
= S_IFREG
;
36 memset(&ii
->i_bmap_data
, 0, sizeof(struct nilfs_bmap
));
37 mapping_set_gfp_mask(btnc_inode
->i_mapping
, GFP_NOFS
);
40 void nilfs_btnode_cache_clear(struct address_space
*btnc
)
42 invalidate_mapping_pages(btnc
, 0, -1);
43 truncate_inode_pages(btnc
, 0);
47 nilfs_btnode_create_block(struct address_space
*btnc
, __u64 blocknr
)
49 struct inode
*inode
= btnc
->host
;
50 struct buffer_head
*bh
;
52 bh
= nilfs_grab_buffer(inode
, btnc
, blocknr
, BIT(BH_NILFS_Node
));
56 if (unlikely(buffer_mapped(bh
) || buffer_uptodate(bh
) ||
61 memset(bh
->b_data
, 0, i_blocksize(inode
));
62 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
63 bh
->b_blocknr
= blocknr
;
64 set_buffer_mapped(bh
);
65 set_buffer_uptodate(bh
);
67 unlock_page(bh
->b_page
);
72 int nilfs_btnode_submit_block(struct address_space
*btnc
, __u64 blocknr
,
73 sector_t pblocknr
, blk_opf_t opf
,
74 struct buffer_head
**pbh
, sector_t
*submit_ptr
)
76 struct buffer_head
*bh
;
77 struct inode
*inode
= btnc
->host
;
81 bh
= nilfs_grab_buffer(inode
, btnc
, blocknr
, BIT(BH_NILFS_Node
));
85 err
= -EEXIST
; /* internal code */
88 if (buffer_uptodate(bh
) || buffer_dirty(bh
))
93 if (inode
->i_ino
!= NILFS_DAT_INO
) {
94 struct the_nilfs
*nilfs
= inode
->i_sb
->s_fs_info
;
96 /* blocknr is a virtual block number */
97 err
= nilfs_dat_translate(nilfs
->ns_dat
, blocknr
,
106 if (opf
& REQ_RAHEAD
) {
107 if (pblocknr
!= *submit_ptr
+ 1 || !trylock_buffer(bh
)) {
108 err
= -EBUSY
; /* internal code */
112 } else { /* opf == REQ_OP_READ */
115 if (buffer_uptodate(bh
)) {
117 err
= -EEXIST
; /* internal code */
120 set_buffer_mapped(bh
);
121 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
122 bh
->b_blocknr
= pblocknr
; /* set block address for read */
123 bh
->b_end_io
= end_buffer_read_sync
;
126 bh
->b_blocknr
= blocknr
; /* set back to the given block address */
127 *submit_ptr
= pblocknr
;
139 * nilfs_btnode_delete - delete B-tree node buffer
140 * @bh: buffer to be deleted
142 * nilfs_btnode_delete() invalidates the specified buffer and delete the page
143 * including the buffer if the page gets unbusy.
145 void nilfs_btnode_delete(struct buffer_head
*bh
)
147 struct address_space
*mapping
;
148 struct page
*page
= bh
->b_page
;
149 pgoff_t index
= page_index(page
);
154 wait_on_page_writeback(page
);
156 nilfs_forget_buffer(bh
);
157 still_dirty
= PageDirty(page
);
158 mapping
= page
->mapping
;
162 if (!still_dirty
&& mapping
)
163 invalidate_inode_pages2_range(mapping
, index
, index
);
167 * nilfs_btnode_prepare_change_key
168 * prepare to move contents of the block for old key to one of new key.
169 * the old buffer will not be removed, but might be reused for new buffer.
170 * it might return -ENOMEM because of memory allocation errors,
171 * and might return -EIO because of disk read errors.
173 int nilfs_btnode_prepare_change_key(struct address_space
*btnc
,
174 struct nilfs_btnode_chkey_ctxt
*ctxt
)
176 struct buffer_head
*obh
, *nbh
;
177 struct inode
*inode
= btnc
->host
;
178 __u64 oldkey
= ctxt
->oldkey
, newkey
= ctxt
->newkey
;
181 if (oldkey
== newkey
)
187 if (inode
->i_blkbits
== PAGE_SHIFT
) {
188 struct page
*opage
= obh
->b_page
;
191 /* BUG_ON(oldkey != obh->b_page->index); */
192 if (unlikely(oldkey
!= opage
->index
))
193 NILFS_PAGE_BUG(opage
,
194 "invalid oldkey %lld (newkey=%lld)",
195 (unsigned long long)oldkey
,
196 (unsigned long long)newkey
);
198 xa_lock_irq(&btnc
->i_pages
);
199 err
= __xa_insert(&btnc
->i_pages
, newkey
, opage
, GFP_NOFS
);
200 xa_unlock_irq(&btnc
->i_pages
);
202 * Note: page->index will not change to newkey until
203 * nilfs_btnode_commit_change_key() will be called.
204 * To protect the page in intermediate state, the page lock
209 else if (err
!= -EBUSY
)
212 err
= invalidate_inode_pages2_range(btnc
, newkey
, newkey
);
215 /* fallback to copy mode */
219 nbh
= nilfs_btnode_create_block(btnc
, newkey
);
228 unlock_page(obh
->b_page
);
233 * nilfs_btnode_commit_change_key
234 * commit the change_key operation prepared by prepare_change_key().
236 void nilfs_btnode_commit_change_key(struct address_space
*btnc
,
237 struct nilfs_btnode_chkey_ctxt
*ctxt
)
239 struct buffer_head
*obh
= ctxt
->bh
, *nbh
= ctxt
->newbh
;
240 __u64 oldkey
= ctxt
->oldkey
, newkey
= ctxt
->newkey
;
243 if (oldkey
== newkey
)
246 if (nbh
== NULL
) { /* blocksize == pagesize */
248 if (unlikely(oldkey
!= opage
->index
))
249 NILFS_PAGE_BUG(opage
,
250 "invalid oldkey %lld (newkey=%lld)",
251 (unsigned long long)oldkey
,
252 (unsigned long long)newkey
);
253 mark_buffer_dirty(obh
);
255 xa_lock_irq(&btnc
->i_pages
);
256 __xa_erase(&btnc
->i_pages
, oldkey
);
257 __xa_set_mark(&btnc
->i_pages
, newkey
, PAGECACHE_TAG_DIRTY
);
258 xa_unlock_irq(&btnc
->i_pages
);
260 opage
->index
= obh
->b_blocknr
= newkey
;
263 nilfs_copy_buffer(nbh
, obh
);
264 mark_buffer_dirty(nbh
);
266 nbh
->b_blocknr
= newkey
;
268 nilfs_btnode_delete(obh
); /* will decrement bh->b_count */
273 * nilfs_btnode_abort_change_key
274 * abort the change_key operation prepared by prepare_change_key().
276 void nilfs_btnode_abort_change_key(struct address_space
*btnc
,
277 struct nilfs_btnode_chkey_ctxt
*ctxt
)
279 struct buffer_head
*nbh
= ctxt
->newbh
;
280 __u64 oldkey
= ctxt
->oldkey
, newkey
= ctxt
->newkey
;
282 if (oldkey
== newkey
)
285 if (nbh
== NULL
) { /* blocksize == pagesize */
286 xa_erase_irq(&btnc
->i_pages
, newkey
);
287 unlock_page(ctxt
->bh
->b_page
);