From 6521f8917082928a4cb637eb64b77b5f2f5b30fc Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 21 Jan 2021 14:19:33 +0100 Subject: namei: prepare for idmapped mounts 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 --- drivers/base/devtmpfs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'drivers/base/devtmpfs.c') diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 2e0c3cdb4184..653c8c6ac7a7 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -162,7 +162,7 @@ static int dev_mkdir(const char *name, umode_t mode) if (IS_ERR(dentry)) return PTR_ERR(dentry); - err = vfs_mkdir(d_inode(path.dentry), dentry, mode); + err = vfs_mkdir(&init_user_ns, d_inode(path.dentry), dentry, mode); if (!err) /* mark as kernel-created inode */ d_inode(dentry)->i_private = &thread; @@ -212,7 +212,8 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid, if (IS_ERR(dentry)) return PTR_ERR(dentry); - err = vfs_mknod(d_inode(path.dentry), dentry, mode, dev->devt); + err = vfs_mknod(&init_user_ns, d_inode(path.dentry), dentry, mode, + dev->devt); if (!err) { struct iattr newattrs; @@ -242,7 +243,8 @@ static int dev_rmdir(const char *name) return PTR_ERR(dentry); if (d_really_is_positive(dentry)) { if (d_inode(dentry)->i_private == &thread) - err = vfs_rmdir(d_inode(parent.dentry), dentry); + err = vfs_rmdir(&init_user_ns, d_inode(parent.dentry), + dentry); else err = -EPERM; } else { @@ -330,7 +332,8 @@ static int handle_remove(const char *nodename, struct device *dev) inode_lock(d_inode(dentry)); notify_change(&init_user_ns, dentry, &newattrs, NULL); inode_unlock(d_inode(dentry)); - err = vfs_unlink(d_inode(parent.dentry), dentry, NULL); + err = vfs_unlink(&init_user_ns, d_inode(parent.dentry), + dentry, NULL); if (!err || err == -ENOENT) deleted = 1; } -- cgit v1.2.3