[PATCH 5.15.y 2/4] ovl: pass ofs to setattr operations

[Sasha Levin <sashal@kernel.org>]

From: Christian Brauner <brauner@kernel.org>

[ Upstream commit 5272eaf3a5682750f6f26ec542b206f0821fb3cb ]

Pass down struct ovl_fs to setattr operations so we can ultimately
retrieve the relevant upper mount and take the mount's idmapping into
account when creating new filesystem objects. This is needed to support
idmapped base layers with overlay.

Cc: <linux-unionfs@vger.kernel.org>
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of: 755b5c5c9277 ("ovl: do not copy up an xattr value that was never read")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/overlayfs/copy_up.c   | 19 +++++++++++--------
 fs/overlayfs/dir.c       |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 4c7ef60dbaac0..fd393716147eb 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -292,7 +292,8 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old,
 	return error;
 }
 
-static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat)
+static int ovl_set_size(struct ovl_fs *ofs,
+			struct dentry *upperdentry, struct kstat *stat)
 {
 	struct iattr attr = {
 		.ia_valid = ATTR_SIZE,
@@ -302,7 +303,8 @@ static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat)
 	return notify_change(&init_user_ns, upperdentry, &attr, NULL);
 }
 
-static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
+static int ovl_set_timestamps(struct ovl_fs *ofs, struct dentry *upperdentry,
+			      struct kstat *stat)
 {
 	struct iattr attr = {
 		.ia_valid =
@@ -314,7 +316,8 @@ static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
 	return notify_change(&init_user_ns, upperdentry, &attr, NULL);
 }
 
-int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
+int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upperdentry,
+		 struct kstat *stat)
 {
 	int err = 0;
 
@@ -334,7 +337,7 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
 		err = notify_change(&init_user_ns, upperdentry, &attr, NULL);
 	}
 	if (!err)
-		ovl_set_timestamps(upperdentry, stat);
+		ovl_set_timestamps(ofs, upperdentry, stat);
 
 	return err;
 }
@@ -540,7 +543,7 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
 
 		if (!err) {
 			/* Restore timestamps on parent (best effort) */
-			ovl_set_timestamps(upperdir, &c->pstat);
+			ovl_set_timestamps(ofs, upperdir, &c->pstat);
 			ovl_dentry_set_upper_alias(c->dentry);
 			ovl_dentry_update_reval(c->dentry, upper);
 		}
@@ -617,9 +620,9 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
 
 	inode_lock(temp->d_inode);
 	if (S_ISREG(c->stat.mode))
-		err = ovl_set_size(temp, &c->stat);
+		err = ovl_set_size(ofs, temp, &c->stat);
 	if (!err)
-		err = ovl_set_attr(temp, &c->stat);
+		err = ovl_set_attr(ofs, temp, &c->stat);
 	inode_unlock(temp->d_inode);
 
 	return err;
@@ -847,7 +850,7 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
 
 		/* Restore timestamps on parent (best effort) */
 		inode_lock(udir);
-		ovl_set_timestamps(c->destdir, &c->pstat);
+		ovl_set_timestamps(ofs, c->destdir, &c->pstat);
 		inode_unlock(udir);
 
 		ovl_dentry_set_upper_alias(c->dentry);
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 5dceb9b076234..9065b69b87971 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -407,7 +407,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
 		goto out_cleanup;
 
 	inode_lock(opaquedir->d_inode);
-	err = ovl_set_attr(opaquedir, &stat);
+	err = ovl_set_attr(ofs, opaquedir, &stat);
 	inode_unlock(opaquedir->d_inode);
 	if (err)
 		goto out_cleanup;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ad011aabfccb2..9f891340d60d8 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -618,7 +618,7 @@ int ovl_copy_up_with_data(struct dentry *dentry);
 int ovl_maybe_copy_up(struct dentry *dentry, int flags);
 int ovl_copy_xattr(struct super_block *sb, struct dentry *old,
 		   struct dentry *new);
-int ovl_set_attr(struct dentry *upper, struct kstat *stat);
+int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat);
 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
 				  bool is_upper);
 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower,
-- 
2.53.0