@@ -1534,16 +1534,36 @@ sector_t bmap(struct inode *inode, sector_t block)
EXPORT_SYMBOL(bmap);
/*
+ * Update times in overlayed inode from underlying real inode
+ */
+static void update_ovl_inode_times(struct dentry *dentry, struct inode *inode,
+ bool rcu)
+{
+ if (!rcu) {
+ struct inode *realinode = d_real_inode(dentry);
+
+ if (unlikely(inode != realinode)) {
+ inode->i_mtime = realinode->i_mtime;
+ inode->i_ctime = realinode->i_ctime;
+ WARN_ON_ONCE(!timespec_equal(&inode->i_atime,
+ &realinode->i_atime));
+ }
+ }
+}
+
+/*
* With relative atime, only update atime if the previous atime is
* earlier than either the ctime or mtime or if at least a day has
* passed since the last atime update.
*/
-static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
- struct timespec now)
+static int relatime_need_update(const struct path *path, struct inode *inode,
+ struct timespec now, bool rcu)
{
- if (!(mnt->mnt_flags & MNT_RELATIME))
+ if (!(path->mnt->mnt_flags & MNT_RELATIME))
return 1;
+
+ update_ovl_inode_times(path->dentry, inode, rcu);
/*
* Is mtime younger than atime? If yes, update atime:
*/
@@ -1610,7 +1630,8 @@ static int update_time(struct inode *inode, struct timespec *time, int flags)
* This function automatically handles read only file systems and media,
* as well as the "noatime" flag and inode specific "noatime" markers.
*/
-bool atime_needs_update(const struct path *path, struct inode *inode)
+static bool __atime_needs_update(const struct path *path, struct inode *inode,
+ bool rcu)
{
struct vfsmount *mnt = path->mnt;
struct timespec now;
@@ -1629,7 +1650,7 @@ bool atime_needs_update(const struct path *path, struct inode *inode)
now = current_fs_time(inode->i_sb);
- if (!relatime_need_update(mnt, inode, now))
+ if (!relatime_need_update(path, inode, now, rcu))
return false;
if (timespec_equal(&inode->i_atime, &now))
@@ -1638,13 +1659,18 @@ bool atime_needs_update(const struct path *path, struct inode *inode)
return true;
}
+bool atime_needs_update(const struct path *path, struct inode *inode)
+{
+ return __atime_needs_update(path, inode, true);
+}
+
void touch_atime(const struct path *path)
{
struct vfsmount *mnt = path->mnt;
struct inode *inode = d_inode(path->dentry);
struct timespec now;
- if (!atime_needs_update(path, inode))
+ if (!__atime_needs_update(path, inode, false))
return;
if (!sb_start_write_trylock(inode->i_sb))
On overlayfs relatime_need_update() needs inode times to be correct on overlay inode. But i_mtime and i_ctime are updated by filesystem code on underlying inode only, so they will be out-of-date on the overlay inode. This patch copies the times from the underlying inode if needed. This can't be done if called from RCU lookup (link following) but link m/ctime are not updated by fs, so this is all right. This patch doesn't change functionality for anything but overlayfs. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> --- fs/inode.c | 38 ++++++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-)