Merge tag 'ovl-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs updates from Miklos Szeredi:
 "Fixes:

   - Resolve mount option conflicts consistently

   - Sync before remount R/O

   - Fix file handle encoding corner cases

   - Fix metacopy related issues

   - Fix an unintialized return value

   - Add missing permission checks for underlying layers

  Optimizations:

   - Allow multipe whiteouts to share an inode

   - Optimize small writes by inheriting SB_NOSEC from upper layer

   - Do not call ->syncfs() multiple times for sync(2)

   - Do not cache negative lookups on upper layer

   - Make private internal mounts longterm"

* tag 'ovl-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (27 commits)
  ovl: remove unnecessary lock check
  ovl: make oip->index bool
  ovl: only pass ->ki_flags to ovl_iocb_to_rwf()
  ovl: make private mounts longterm
  ovl: get rid of redundant members in struct ovl_fs
  ovl: add accessor for ofs->upper_mnt
  ovl: initialize error in ovl_copy_xattr
  ovl: drop negative dentry in upper layer
  ovl: check permission to open real file
  ovl: call secutiry hook in ovl_real_ioctl()
  ovl: verify permissions in ovl_path_open()
  ovl: switch to mounter creds in readdir
  ovl: pass correct flags for opening real directory
  ovl: fix redirect traversal on metacopy dentries
  ovl: initialize OVL_UPPERDATA in ovl_lookup()
  ovl: use only uppermetacopy state in ovl_lookup()
  ovl: simplify setting of origin for index lookup
  ovl: fix out of bounds access warning in ovl_check_fb_len()
  ovl: return required buffer size for file handles
  ovl: sync dirty data when remounting to ro mode
  ...

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 6d499ab254b7..7cd642409165 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1937,6 +1937,9 @@ struct vfsmount *clone_private_mount(const struct path *path)
 	if (IS_ERR(new_mnt))
 		return ERR_CAST(new_mnt);
 
+	/* Longterm mount to be removed by kern_unmount*() */
+	new_mnt->mnt_ns = MNT_NS_INTERNAL;
+
 	return &new_mnt->mnt;
 }
 EXPORT_SYMBOL_GPL(clone_private_mount);
@@ -3863,6 +3866,19 @@ void kern_unmount(struct vfsmount *mnt)
 }
 EXPORT_SYMBOL(kern_unmount);
 
+void kern_unmount_array(struct vfsmount *mnt[], unsigned int num)
+{
+	unsigned int i;
+
+	for (i = 0; i < num; i++)
+		if (mnt[i])
+			real_mount(mnt[i])->mnt_ns = NULL;
+	synchronize_rcu_expedited();
+	for (i = 0; i < num; i++)
+		mntput(mnt[i]);
+}
+EXPORT_SYMBOL(kern_unmount_array);
+
 bool our_mnt(struct vfsmount *mnt)
 {
 	return check_mnt(real_mount(mnt));