kernel.git/fs/udf/file.c, branch linux-5.12.y

fs: make helpers idmap mount aware

2021-01-24T13:27:20Z

Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-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

attr: handle idmapped mounts

2021-01-24T13:27:16Z

When file attributes are changed most filesystems rely on the setattr_prepare(), setattr_copy(), and notify_change() helpers for initialization and permission checking. Let them handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the checks 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. Helpers that perform checks on the ia_uid and ia_gid fields in struct iattr assume that ia_uid and ia_gid are intended values and have already been mapped correctly at the userspace-kernelspace boundary as we already do today. 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/20210121131959.646623-8-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: add file and path permissions helpers

2021-01-24T13:27:16Z

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

udf: Remove pointless union in udf_inode_info

2020-09-29T15:21:54Z

We use only a single member out of the i_ext union in udf_inode_info. Just remove the pointless union. Signed-off-by: Jan Kara

udf: augment UDF permissions on new inodes

2019-08-27T13:38:46Z

Windows presents files created within Linux as read-only, even when permissions in Linux indicate the file should be writable. UDF defines a slightly different set of basic file permissions than Linux. Specifically, UDF has "delete" and "change attribute" permissions for each access class (user/group/other). Linux has no equivalents for these. When the Linux UDF driver creates a file (or directory), no UDF delete or change attribute permissions are granted. The lack of delete permission appears to cause Windows to mark an item read-only when its permissions otherwise indicate that it should be read-write. Fix this by having UDF delete permissions track Linux write permissions. Also grant UDF change attribute permission to the owner when creating a new inode. Reported by: Ty Young Signed-off-by: Steven J. Magnani Link: https://lore.kernel.org/r/20190827121359.9954-1-steve@digidescorp.com Signed-off-by: Jan Kara

udf: Apply uid/gid mount options also to new inodes & chown

2018-02-27T09:25:33Z

Currently newly created files belong to current user despite uid= / gid= mount options. This is confusing to users (as owner of the file will change after remount / eviction from cache) and also inconsistent with e.g. FAT with the same mount option. So apply uid= and gid= also to newly created inodes and similarly as FAT disallow to change owner of the file in this case. Reported-by: Steve Kenton Reviewed-by: Pali Rohár Signed-off-by: Jan Kara

udf: Use i_size_read() in udf_adinicb_writepage()

2017-06-14T09:21:01Z

We don't hold inode_lock in udf_adinicb_writepage() so use i_size_read() to get i_size. This cannot cause real problems is i_size is guaranteed to be small but let's be careful. Signed-off-by: Jan Kara

udf: Fix races with i_size changes during readpage

2017-06-14T09:21:01Z

__udf_adinicb_readpage() uses i_size several times. When truncate changes i_size while the function is running, it can observe several different values and thus e.g. expose uninitialized parts of page to userspace. Also use i_size_read() in the function since it does not hold inode_lock. Since i_size is guaranteed to be small, this cannot really cause any issues even on 32-bit archs but let's be careful. CC: stable@vger.kernel.org Fixes: 9c2fc0de1a6e638fe58c354a463f544f42a90a09 Signed-off-by: Jan Kara

udf: use kmap_atomic for memcpy copying

2017-04-24T14:28:02Z

Use temporary mapping for memory copying operations. To avoid any sleeping problem, mark_inode_dirty(inode) was moved after kunmap() in udf_adinicb_readpage() down_write(&iinfo->i_data_sem) set before kmap_atomic() in udf_expand_file_adinicb() Signed-off-by: Fabian Frederick Signed-off-by: Jan Kara

udf: simplify udf_ioctl()

2017-02-03T15:24:18Z

"out" label was only returning error code. Signed-off-by: Fabian Frederick Signed-off-by: Jan Kara