return false;
}
-/* Is IO overwriting allocated and initialized blocks? */
-static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
+/* Is IO overwriting allocated or initialized blocks? */
+static bool ext4_overwrite_io(struct inode *inode,
+ loff_t pos, loff_t len, bool *unwritten)
{
struct ext4_map_blocks map;
unsigned int blkbits = inode->i_blkbits;
blklen = map.m_len;
err = ext4_map_blocks(NULL, inode, &map, 0);
+ if (err != blklen)
+ return false;
/*
* 'err==len' means that all of the blocks have been preallocated,
- * regardless of whether they have been initialized or not. To exclude
- * unwritten extents, we need to check m_flags.
+ * regardless of whether they have been initialized or not. We need to
+ * check m_flags to distinguish the unwritten extents.
*/
- return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
+ *unwritten = !(map.m_flags & EXT4_MAP_MAPPED);
+ return true;
}
static ssize_t ext4_generic_write_checks(struct kiocb *iocb,
* - For extending writes case we don't take the shared lock, since it requires
* updating inode i_disksize and/or orphan handling with exclusive lock.
*
- * - shared locking will only be true mostly with overwrites. Otherwise we will
- * switch to exclusive i_rwsem lock.
+ * - shared locking will only be true mostly with overwrites, including
+ * initialized blocks and unwritten blocks. For overwrite unwritten blocks
+ * we protect splitting extents by i_data_sem in ext4_inode_info, so we can
+ * also release exclusive i_rwsem lock.
+ *
+ * - Otherwise we will switch to exclusive i_rwsem lock.
*/
static ssize_t ext4_dio_write_checks(struct kiocb *iocb, struct iov_iter *from,
- bool *ilock_shared, bool *extend)
+ bool *ilock_shared, bool *extend,
+ bool *unwritten)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
* in file_modified().
*/
if (*ilock_shared && (!IS_NOSEC(inode) || *extend ||
- !ext4_overwrite_io(inode, offset, count))) {
+ !ext4_overwrite_io(inode, offset, count, unwritten))) {
if (iocb->ki_flags & IOCB_NOWAIT) {
ret = -EAGAIN;
goto out;
loff_t offset = iocb->ki_pos;
size_t count = iov_iter_count(from);
const struct iomap_ops *iomap_ops = &ext4_iomap_ops;
- bool extend = false, unaligned_io = false;
+ bool extend = false, unaligned_io = false, unwritten = false;
bool ilock_shared = true;
/*
return ext4_buffered_write_iter(iocb, from);
}
- ret = ext4_dio_write_checks(iocb, from, &ilock_shared, &extend);
+ ret = ext4_dio_write_checks(iocb, from,
+ &ilock_shared, &extend, &unwritten);
if (ret <= 0)
return ret;
ext4_journal_stop(handle);
}
- if (ilock_shared)
+ if (ilock_shared && !unwritten)
iomap_ops = &ext4_iomap_overwrite_ops;
ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
(unaligned_io || extend) ? IOMAP_DIO_FORCE_WAIT : 0,