kernel/linux.git/fs/init.c, branch v6.1.168

init: handle idmapped mounts

2021-01-24T13:27:19+00:00

Enable the init helpers to handle idmapped mounts by passing down the mount's user namespace. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-21-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

namei: prepare for idmapped mounts

2021-01-24T13:27:18+00:00

The various vfs_*() helpers are called by filesystems or by the vfs itself to perform core operations such as create, link, mkdir, mknod, rename, rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace and pass it down. Afterwards the checks and operations are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-15-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

namei: handle idmapped mounts in may_*() helpers

2021-01-24T13:27:17+00:00

The may_follow_link(), may_linkat(), may_lookup(), may_open(), may_o_create(), may_create_in_sticky(), may_delete(), and may_create() helpers determine whether the caller is privileged enough to perform the associated operations. Let them handle idmapped mounts by mapping the inode or fsids according to the mount's user namespace. Afterwards the checks are identical to non-idmapped inodes. The patch takes care to retrieve the mount's user namespace right before performing permission checks and passing it down into the fileystem so the user namespace can't change in between by someone idmapping a mount that is currently not idmapped. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-13-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner

fs: add file and path permissions helpers

2021-01-24T13:27:16+00:00

Add two simple helpers to check permissions on a file and path respectively and convert over some callers. It simplifies quite a few codepaths and also reduces the churn in later patches quite a bit. Christoph also correctly points out that this makes codepaths (e.g. ioctls) way easier to follow that would otherwise have to do more complex argument passing than necessary. Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner

init: add an init_dup helper

2020-08-05T01:02:38+00:00

Add a simple helper to grab a reference to a file and install it at the next available fd, and switch the early init code over to it. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

init: add an init_utimes helper

2020-07-31T06:17:54+00:00

Add a simple helper to set timestamps with a kernel space file name and switch the early init code over to it. Signed-off-by: Christoph Hellwig

init: add an init_stat helper

2020-07-31T06:17:54+00:00

Add a simple helper to stat with a kernel space file name and switch the early init code over to it. Signed-off-by: Christoph Hellwig

init: add an init_mknod helper

2020-07-31T06:17:54+00:00

Add a simple helper to mknod with a kernel space file name and switch the early init code over to it. Remove the now unused ksys_mknod. Signed-off-by: Christoph Hellwig

init: add an init_mkdir helper

2020-07-31T06:17:53+00:00

Add a simple helper to mkdir with a kernel space file name and switch the early init code over to it. Remove the now unused ksys_mkdir. Signed-off-by: Christoph Hellwig

init: add an init_symlink helper

2020-07-31T06:17:53+00:00

Add a simple helper to symlink with a kernel space file name and switch the early init code over to it. Remove the now unused ksys_symlink. Signed-off-by: Christoph Hellwig