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 --- fs/ecryptfs/inode.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index ff48abb09679..73e3d47e7b2d 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -141,7 +141,8 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry, else if (d_unhashed(lower_dentry)) rc = -EINVAL; else - rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL); + rc = vfs_unlink(&init_user_ns, lower_dir_inode, lower_dentry, + NULL); if (rc) { printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc); goto out_unlock; @@ -180,7 +181,8 @@ ecryptfs_do_create(struct inode *directory_inode, lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); lower_dir_dentry = lock_parent(lower_dentry); - rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true); + rc = vfs_create(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry, + mode, true); if (rc) { printk(KERN_ERR "%s: Failure to create dentry in lower fs; " "rc = [%d]\n", __func__, rc); @@ -190,7 +192,8 @@ ecryptfs_do_create(struct inode *directory_inode, inode = __ecryptfs_get_inode(d_inode(lower_dentry), directory_inode->i_sb); if (IS_ERR(inode)) { - vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL); + vfs_unlink(&init_user_ns, d_inode(lower_dir_dentry), + lower_dentry, NULL); goto out_lock; } fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry)); @@ -436,8 +439,8 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, dget(lower_old_dentry); dget(lower_new_dentry); lower_dir_dentry = lock_parent(lower_new_dentry); - rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry), - lower_new_dentry, NULL); + rc = vfs_link(lower_old_dentry, &init_user_ns, + d_inode(lower_dir_dentry), lower_new_dentry, NULL); if (rc || d_really_is_negative(lower_new_dentry)) goto out_lock; rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb); @@ -481,7 +484,7 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, strlen(symname)); if (rc) goto out_lock; - rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry, + rc = vfs_symlink(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry, encoded_symname); kfree(encoded_symname); if (rc || d_really_is_negative(lower_dentry)) @@ -507,7 +510,8 @@ static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode lower_dentry = ecryptfs_dentry_to_lower(dentry); lower_dir_dentry = lock_parent(lower_dentry); - rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode); + rc = vfs_mkdir(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry, + mode); if (rc || d_really_is_negative(lower_dentry)) goto out; rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb); @@ -541,7 +545,7 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry) else if (d_unhashed(lower_dentry)) rc = -EINVAL; else - rc = vfs_rmdir(lower_dir_inode, lower_dentry); + rc = vfs_rmdir(&init_user_ns, lower_dir_inode, lower_dentry); if (!rc) { clear_nlink(d_inode(dentry)); fsstack_copy_attr_times(dir, lower_dir_inode); @@ -563,7 +567,8 @@ ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev lower_dentry = ecryptfs_dentry_to_lower(dentry); lower_dir_dentry = lock_parent(lower_dentry); - rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev); + rc = vfs_mknod(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry, + mode, dev); if (rc || d_really_is_negative(lower_dentry)) goto out; rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb); @@ -621,10 +626,12 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_lock; } - rd.old_dir = d_inode(lower_old_dir_dentry); - rd.old_dentry = lower_old_dentry; - rd.new_dir = d_inode(lower_new_dir_dentry); - rd.new_dentry = lower_new_dentry; + rd.old_mnt_userns = &init_user_ns; + rd.old_dir = d_inode(lower_old_dir_dentry); + rd.old_dentry = lower_old_dentry; + rd.new_mnt_userns = &init_user_ns; + rd.new_dir = d_inode(lower_new_dir_dentry); + rd.new_dentry = lower_new_dentry; rc = vfs_rename(&rd); if (rc) goto out_lock; -- cgit