linux-dev/fs/overlayfs, branch linus/master

Merge tag 'ovl-update-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

2022-05-30T18:19:16Z

Pull overlayfs updates from Miklos Szeredi: - Support idmapped layers in overlayfs (Christian Brauner) - Add a fix to exportfs that is relevant to open_by_handle_at(2) as well - Introduce new lookup helpers that allow passing mnt_userns into inode_permission() * tag 'ovl-update-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: support idmapped layers ovl: handle idmappings in ovl_xattr_{g,s}et() ovl: handle idmappings in layer open helpers ovl: handle idmappings in ovl_permission() ovl: use ovl_copy_{real,upper}attr() wrappers ovl: store lower path in ovl_inode ovl: handle idmappings for layer lookup ovl: handle idmappings for layer fileattrs ovl: use ovl_path_getxattr() wrapper ovl: use ovl_lookup_upper() wrapper ovl: use ovl_do_notify_change() wrapper ovl: pass layer mnt to ovl_open_realfile() ovl: pass ofs to setattr operations ovl: handle idmappings in creation operations ovl: add ovl_upper_mnt_userns() wrapper ovl: pass ofs to creation operations ovl: use wrappers to all vfs_*xattr() calls exportfs: support idmapped mounts fs: add two trivial lookup helpers

VFS: add FMODE_CAN_ODIRECT file flag

2022-05-10T01:20:49Z

Currently various places test if direct IO is possible on a file by checking for the existence of the direct_IO address space operation. This is a poor choice, as the direct_IO operation may not be used - it is only used if the generic_file_*_iter functions are called for direct IO and some filesystems - particularly NFS - don't do this. Instead, introduce a new f_mode flag: FMODE_CAN_ODIRECT and change the various places to check this (avoiding pointer dereferences). do_dentry_open() will set this flag if ->direct_IO is present, so filesystems do not need to be changed. NFS *is* changed, to set the flag explicitly and discard the direct_IO entry in the address_space_operations for files. Other filesystems which currently use noop_direct_IO could usefully be changed to set this flag instead. Link: https://lkml.kernel.org/r/164859778128.29473.15189737957277399416.stgit@noble.brown Reviewed-by: Christoph Hellwig Signed-off-by: NeilBrown Tested-by: David Howells Tested-by: Geert Uytterhoeven Cc: Hugh Dickins Cc: Mel Gorman Cc: Trond Myklebust Cc: Miaohe Lin Signed-off-by: Andrew Morton

ovl: support idmapped layers

2022-04-28T14:31:12Z

Now that overlay is able to take a layers idmapping into account allow overlay mounts to be created on top of idmapped mounts. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: handle idmappings in ovl_xattr_{g,s}et()

2022-04-28T14:31:12Z

When retrieving xattrs from the upper or lower layers take the relevant mount's idmapping into account. We rely on the previously introduced ovl_i_path_real() helper to retrieve the relevant path. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: handle idmappings in layer open helpers

2022-04-28T14:31:12Z

In earlier patches we already passed down the relevant upper or lower path to ovl_open_realfile(). Now let the open helpers actually take the idmapping of the relevant mount into account when checking permissions. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: handle idmappings in ovl_permission()

2022-04-28T14:31:12Z

Use the previously introduced ovl_i_path_real() helper to retrieve the relevant upper or lower path and take the mount's idmapping into account for the lower layer permission check. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: use ovl_copy_{real,upper}attr() wrappers

2022-04-28T14:31:12Z

When copying inode attributes from the upper or lower layer to ovl inodes we need to take the upper or lower layer's mount's idmapping into account. In a lot of places we call ovl_copyattr() only on upper inodes and in some we call it on either upper or lower inodes. Split this into two separate helpers. The first one should only be called on upper inodes and is thus called ovl_copy_upperattr(). The second one can be called on upper or lower inodes. We add ovl_copy_realattr() for this task. The new helper makes use of the previously added ovl_i_path_real() helper. This is needed to support idmapped base layers with overlay. When overlay copies the inode information from an upper or lower layer to the relevant overlay inode it will apply the idmapping of the upper or lower layer when doing so. The ovl inode ownership will thus always correctly reflect the ownership of the idmapped upper or lower layer. All idmapping helpers are nops when no idmapped base layers are used. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: store lower path in ovl_inode

2022-04-28T14:31:12Z

Create some ovl_i_* helpers to get real path from ovl inode. Instead of just stashing struct inode for the lower layer we stash struct path for the lower layer. The helpers allow to retrieve a struct path for the relevant upper or lower layer. This will be used when retrieving information based on struct inode when copying up inode attributes from upper or lower inodes to ovl inodes and when checking permissions in ovl_permission() in following patches. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: handle idmappings for layer lookup

2022-04-28T14:31:12Z

Make the two places where lookup helpers can be called either on lower or upper layers take the mount's idmapping into account. To this end we pass down the mount in struct ovl_lookup_data. It can later also be used to construct struct path for various other helpers. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi

ovl: handle idmappings for layer fileattrs

2022-04-28T14:31:11Z

Take the upper mount's idmapping into account when setting fileattrs on the upper layer. This is needed to support idmapped base layers with overlay. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Miklos Szeredi