cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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truncate.h (1551B)

      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