f2fs: fix to update time in lazytime mode

generic/018 reports an inconsistent status of atime, the
testcase is as below:
- open file with O_SYNC
- write file to construct fraged space
- calc md5 of file
- record {a,c,m}time
- defrag file --- do nothing
- umount & mount
- check {a,c,m}time

The root cause is, as f2fs enables lazytime by default, atime
update will dirty vfs inode, rather than dirtying f2fs inode (by set
with FI_DIRTY_INODE), so later f2fs_write_inode() called from VFS will
fail to update inode page due to our skip:

f2fs_write_inode()
	if (is_inode_flag_set(inode, FI_DIRTY_INODE))
		return 0;

So eventually, after evict(), we lose last atime for ever.

To fix this issue, we need to check whether {a,c,m,cr}time is
consistent in between inode cache and inode page, and only skip
f2fs_update_inode() if f2fs inode is not dirty and time is
consistent as well.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2019-09-27 18:01:35 +08:00 committed by Jaegeuk Kim
parent b145b0eb20
commit fe1897eaa6
2 changed files with 20 additions and 9 deletions

View File

@ -2704,6 +2704,20 @@ static inline void clear_file(struct inode *inode, int type)
f2fs_mark_inode_dirty_sync(inode, true);
}
static inline bool f2fs_is_time_consistent(struct inode *inode)
{
if (!timespec64_equal(F2FS_I(inode)->i_disk_time, &inode->i_atime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 1, &inode->i_ctime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 2, &inode->i_mtime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 3,
&F2FS_I(inode)->i_crtime))
return false;
return true;
}
static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
{
bool ret;
@ -2721,14 +2735,7 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
i_size_read(inode) & ~PAGE_MASK)
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time, &inode->i_atime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 1, &inode->i_ctime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 2, &inode->i_mtime))
return false;
if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 3,
&F2FS_I(inode)->i_crtime))
if (!f2fs_is_time_consistent(inode))
return false;
down_read(&F2FS_I(inode)->i_sem);

View File

@ -615,7 +615,11 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
inode->i_ino == F2FS_META_INO(sbi))
return 0;
if (!is_inode_flag_set(inode, FI_DIRTY_INODE))
/*
* atime could be updated without dirtying f2fs inode in lazytime mode
*/
if (f2fs_is_time_consistent(inode) &&
!is_inode_flag_set(inode, FI_DIRTY_INODE))
return 0;
if (!f2fs_is_checkpoint_ready(sbi))