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 */
12static 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 */
30static 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

 
 1/*
 2 * linux/fs/ext4/truncate.h
 3 *
 4 * Common inline functions needed for truncate support
 5 */
 6
 7/*
 8 * Truncate blocks that were not used by write. We have to truncate the
 9 * pagecache as well so that corresponding buffers get properly unmapped.
10 */
11static inline void ext4_truncate_failed_write(struct inode *inode)
12{
13	truncate_inode_pages(inode->i_mapping, inode->i_size);
 
 
 
 
 
 
 
14	ext4_truncate(inode);
 
15}
16
17/*
18 * Work out how many blocks we need to proceed with the next chunk of a
19 * truncate transaction.
20 */
21static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
22{
23	ext4_lblk_t needed;
24
25	needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
26
27	/* Give ourselves just enough room to cope with inodes in which
28	 * i_blocks is corrupt: we've seen disk corruptions in the past
29	 * which resulted in random data in an inode which looked enough
30	 * like a regular file for ext4 to try to delete it.  Things
31	 * will go a bit crazy if that happens, but at least we should
32	 * try not to panic the whole kernel. */
33	if (needed < 2)
34		needed = 2;
35
36	/* But we need to bound the transaction so we don't overflow the
37	 * journal. */
38	if (needed > EXT4_MAX_TRANS_DATA)
39		needed = EXT4_MAX_TRANS_DATA;
40
41	return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
42}
43