1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/ext4/truncate.h |
4 | * |
5 | * Common inline functions needed for truncate support |
6 | */ |
7 | |
8 | /* |
9 | * Truncate blocks that were not used by write. We have to truncate the |
10 | * pagecache as well so that corresponding buffers get properly unmapped. |
11 | */ |
12 | static inline void ext4_truncate_failed_write(struct inode *inode) |
13 | { |
14 | struct address_space *mapping = inode->i_mapping; |
15 | |
16 | /* |
17 | * We don't need to call ext4_break_layouts() because the blocks we |
18 | * are truncating were never visible to userspace. |
19 | */ |
20 | filemap_invalidate_lock(mapping); |
21 | truncate_inode_pages(mapping, inode->i_size); |
22 | ext4_truncate(inode); |
23 | filemap_invalidate_unlock(mapping); |
24 | } |
25 | |
26 | /* |
27 | * Work out how many blocks we need to proceed with the next chunk of a |
28 | * truncate transaction. |
29 | */ |
30 | static inline unsigned long ext4_blocks_for_truncate(struct inode *inode) |
31 | { |
32 | ext4_lblk_t needed; |
33 | |
34 | needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); |
35 | |
36 | /* Give ourselves just enough room to cope with inodes in which |
37 | * i_blocks is corrupt: we've seen disk corruptions in the past |
38 | * which resulted in random data in an inode which looked enough |
39 | * like a regular file for ext4 to try to delete it. Things |
40 | * will go a bit crazy if that happens, but at least we should |
41 | * try not to panic the whole kernel. */ |
42 | if (needed < 2) |
43 | needed = 2; |
44 | |
45 | /* But we need to bound the transaction so we don't overflow the |
46 | * journal. */ |
47 | if (needed > EXT4_MAX_TRANS_DATA) |
48 | needed = EXT4_MAX_TRANS_DATA; |
49 | |
50 | return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
51 | } |
52 | |
53 | |