[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)
{
	/*
	 * We don't need to call ext4_break_layouts() because the blocks we
	 * are truncating were never visible to userspace.
	 */
	down_write(&EXT4_I(inode)->i_mmap_sem);
	truncate_inode_pages(inode->i_mapping, inode->i_size);
	ext4_truncate(inode);
	up_write(&EXT4_I(inode)->i_mmap_sem);
}

/*
 * 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	{
430657b6 RZ	14	/*
	15	* We don't need to call ext4_break_layouts() because the blocks we
	16	* are truncating were never visible to userspace.
	17	*/
ea3d7209	18	down_write(&EXT4_I(inode)->i_mmap_sem);
9f125d64 TT	19	truncate_inode_pages(inode->i_mapping, inode->i_size);
9f125d64 TT	20	ext4_truncate(inode);
ea3d7209	21	up_write(&EXT4_I(inode)->i_mmap_sem);
9f125d64 TT	22	}
	23
	24	/*
	25	* Work out how many blocks we need to proceed with the next chunk of a
	26	* truncate transaction.
	27	*/
	28	static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
	29	{
	30	ext4_lblk_t needed;
	31
	32	needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
	33
	34	/* Give ourselves just enough room to cope with inodes in which
	35	* i_blocks is corrupt: we've seen disk corruptions in the past
	36	* which resulted in random data in an inode which looked enough
	37	* like a regular file for ext4 to try to delete it. Things
	38	* will go a bit crazy if that happens, but at least we should
	39	* try not to panic the whole kernel. */
	40	if (needed < 2)
	41	needed = 2;
	42
	43	/* But we need to bound the transaction so we don't overflow the
	44	* journal. */
	45	if (needed > EXT4_MAX_TRANS_DATA)
	46	needed = EXT4_MAX_TRANS_DATA;
	47
	48	return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
	49	}
	50