[linux.git] / fs / ext4 / truncate.h

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/fs/ext4/truncate.h
 *
 * Common inline functions needed for truncate support
 */

/*
 * Truncate blocks that were not used by write. We have to truncate the
 * pagecache as well so that corresponding buffers get properly unmapped.
 */
static inline void ext4_truncate_failed_write(struct inode *inode)
{
	struct address_space *mapping = inode->i_mapping;

	/*
	 * We don't need to call ext4_break_layouts() because the blocks we
	 * are truncating were never visible to userspace.
	 */
	filemap_invalidate_lock(mapping);
	truncate_inode_pages(mapping, inode->i_size);
	ext4_truncate(inode);
	filemap_invalidate_unlock(mapping);
}

/*
 * Work out how many blocks we need to proceed with the next chunk of a
 * truncate transaction.
 */
static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
{
	ext4_lblk_t needed;

	needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);

	/* Give ourselves just enough room to cope with inodes in which
	 * i_blocks is corrupt: we've seen disk corruptions in the past
	 * which resulted in random data in an inode which looked enough
	 * like a regular file for ext4 to try to delete it.  Things
	 * will go a bit crazy if that happens, but at least we should
	 * try not to panic the whole kernel. */
	if (needed < 2)
		needed = 2;

	/* But we need to bound the transaction so we don't overflow the
	 * journal. */
	if (needed > EXT4_MAX_TRANS_DATA)
		needed = EXT4_MAX_TRANS_DATA;

	return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
}
Commit	Line	Data
f5166768	1	// SPDX-License-Identifier: GPL-2.0
9f125d64 TT	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	{
d4f5258e JK	14	struct address_space *mapping = inode->i_mapping;
d4f5258e JK	15
430657b6 RZ	16	/*
	17	* We don't need to call ext4_break_layouts() because the blocks we
	18	* are truncating were never visible to userspace.
	19	*/
d4f5258e JK	20	filemap_invalidate_lock(mapping);
d4f5258e JK	21	truncate_inode_pages(mapping, inode->i_size);
9f125d64	22	ext4_truncate(inode);
d4f5258e	23	filemap_invalidate_unlock(mapping);
9f125d64 TT	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