diff options
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 7ac0a81bd371..6e9f198ecacf 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -202,8 +202,9 @@ ext4_extending_io(struct inode *inode, loff_t offset, size_t len) 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; @@ -217,12 +218,15 @@ static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len) 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, @@ -431,11 +435,16 @@ static const struct iomap_dio_ops ext4_dio_write_ops = { * - 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); @@ -459,7 +468,7 @@ restart: * 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; @@ -491,7 +500,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) 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; /* @@ -534,7 +543,8 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) 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; @@ -582,7 +592,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) 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, |