diff options
Diffstat (limited to 'fs/ext4/truncate.h')
| -rw-r--r-- | fs/ext4/truncate.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/fs/ext4/truncate.h b/fs/ext4/truncate.h new file mode 100644 index 000000000..bcbe3668c --- /dev/null +++ b/fs/ext4/truncate.h @@ -0,0 +1,50 @@ +// 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; +} + |