Commit fe1897ea authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

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: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent b145b0eb

fs/f2fs/f2fs.h

+15 −8
Original line number Diff line number Diff line
@@ -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);

fs/f2fs/inode.c

+5 −1
Original line number Diff line number Diff line
@@ -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))

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