From: Eric Biggers <ebiggers@xxxxxxxxxx>
Implement the new ->lazytime_expired method to get notified of lazytime
timestamp expirations, instead of relying on ->dirty_inode(inode,
I_DIRTY_SYNC) which is potentially ambiguous.
This fixes a bug where XFS didn't write lazytime timestamps to disk upon
a sync(), or after 24 hours (dirtytime_expire_interval * 2). This is
because it only wrote the timestamps if I_DIRTY_TIME was set in i_state.
But actually when an inode's timestamps expire without the inode being
marked I_DIRTY_SYNC first, then ->dirty_inode isn't called until
__writeback_single_inode() has already cleared I_DIRTY_TIME in i_state.
The new ->lazytime_expired method is unambiguous, so it removes any need
to check for I_DIRTY_TIME, which avoids this bug.
I've written an xfstest which reproduces this bug.
Fixes: c3b1b13190ae ("xfs: implement the lazytime mount option")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
fs/xfs/xfs_super.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 813be879a5e51..0b7623907b264 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -666,19 +666,13 @@ xfs_fs_destroy_inode(
}
static void
-xfs_fs_dirty_inode(
- struct inode *inode,
- int flag)
+xfs_fs_lazytime_expired(
+ struct inode *inode)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
- if (!(inode->i_sb->s_flags & SB_LAZYTIME))
- return;
- if (flag != I_DIRTY_SYNC || !(inode->i_state & I_DIRTY_TIME))
- return;
-
if (xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp))
return;
xfs_ilock(ip, XFS_ILOCK_EXCL);
@@ -1108,7 +1102,7 @@ xfs_fs_free_cached_objects(
static const struct super_operations xfs_super_operations = {
.alloc_inode = xfs_fs_alloc_inode,
.destroy_inode = xfs_fs_destroy_inode,
- .dirty_inode = xfs_fs_dirty_inode,
+ .lazytime_expired = xfs_fs_lazytime_expired,
.drop_inode = xfs_fs_drop_inode,
.put_super = xfs_fs_put_super,
.sync_fs = xfs_fs_sync_fs,
--
2.30.0
