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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ext4/truncate.h4 *5 * Common inline functions needed for truncate support6 */7 8/*9 * Truncate blocks that were not used by write. We have to truncate the10 * 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 we18 * 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 a28 * 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 which37 * i_blocks is corrupt: we've seen disk corruptions in the past38 * which resulted in random data in an inode which looked enough39 * like a regular file for ext4 to try to delete it. Things40 * will go a bit crazy if that happens, but at least we should41 * 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 the46 * 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