user/sven/linux.git/include/linux/fscrypt.h, branch v5.3.2

fscrypt: support decrypting multiple filesystem blocks per page

2019-05-28T17:27:53Z

Rename fscrypt_decrypt_page() to fscrypt_decrypt_pagecache_blocks() and redefine its behavior to decrypt all filesystem blocks in the given region of the given page, rather than assuming that the region consists of just one filesystem block. Also remove the 'inode' and 'lblk_num' parameters, since they can be retrieved from the page as it's already assumed to be a pagecache page. This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. This is based on work by Chandan Rajendra. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: introduce fscrypt_decrypt_block_inplace()

2019-05-28T17:27:53Z

Currently fscrypt_decrypt_page() does one of two logically distinct things depending on whether FS_CFLG_OWN_PAGES is set in the filesystem's fscrypt_operations: decrypt a pagecache page in-place, or decrypt a filesystem block in-place in any page. Currently these happen to share the same implementation, but this conflates the notion of blocks and pages. It also makes it so that all callers have to provide inode and lblk_num, when fscrypt could determine these itself for pagecache pages. Therefore, move the FS_CFLG_OWN_PAGES behavior into a new function fscrypt_decrypt_block_inplace(). This mirrors fscrypt_encrypt_block_inplace(). This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: support encrypting multiple filesystem blocks per page

2019-05-28T17:27:53Z

Rename fscrypt_encrypt_page() to fscrypt_encrypt_pagecache_blocks() and redefine its behavior to encrypt all filesystem blocks from the given region of the given page, rather than assuming that the region consists of just one filesystem block. Also remove the 'inode' and 'lblk_num' parameters, since they can be retrieved from the page as it's already assumed to be a pagecache page. This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. This is based on work by Chandan Rajendra. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: introduce fscrypt_encrypt_block_inplace()

2019-05-28T17:27:52Z

fscrypt_encrypt_page() behaves very differently depending on whether the filesystem set FS_CFLG_OWN_PAGES in its fscrypt_operations. This makes the function difficult to understand and document. It also makes it so that all callers have to provide inode and lblk_num, when fscrypt could determine these itself for pagecache pages. Therefore, move the FS_CFLG_OWN_PAGES behavior into a new function fscrypt_encrypt_block_inplace(). This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: remove the "write" part of struct fscrypt_ctx

2019-05-28T17:27:52Z

Now that fscrypt_ctx is not used for writes, remove the 'w' fields. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: simplify bounce page handling

2019-05-28T17:27:52Z

Currently, bounce page handling for writes to encrypted files is unnecessarily complicated. A fscrypt_ctx is allocated along with each bounce page, page_private(bounce_page) points to this fscrypt_ctx, and fscrypt_ctx::w::control_page points to the original pagecache page. However, because writes don't use the fscrypt_ctx for anything else, there's no reason why page_private(bounce_page) can't just point to the original pagecache page directly. Therefore, this patch makes this change. In the process, it also cleans up the API exposed to filesystems that allows testing whether a page is a bounce page, getting the pagecache page from a bounce page, and freeing a bounce page. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers

Merge tag 'upstream-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

2019-05-12T22:16:31Z

Pull UBI/UBIFS updates from Richard Weinberger: - fscrypt framework usage updates - One huge fix for xattr unlink - Cleanup of fscrypt ifdefs - Fix for our new UBIFS auth feature * tag 'upstream-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: ubi: wl: Fix uninitialized variable ubifs: Drop unnecessary setting of zbr->znode ubifs: Remove ifdefs around CONFIG_UBIFS_ATIME_SUPPORT ubifs: Remove #ifdef around CONFIG_FS_ENCRYPTION ubifs: Limit number of xattrs per inode ubifs: orphan: Handle xattrs like files ubifs: journal: Handle xattrs like files ubifs: find.c: replace swap function with built-in one ubifs: Do not skip hash checking in data nodes ubifs: work around high stack usage with clang ubifs: remove unused function __ubifs_shash_final ubifs: remove unnecessary #ifdef around fscrypt_ioctl_get_policy() ubifs: remove unnecessary calls to set up directory key

ubifs: Remove #ifdef around CONFIG_FS_ENCRYPTION

2019-05-07T19:58:31Z

ifdefs reduce readablity and compile coverage. This removes the ifdefs around CONFIG_FS_ENCRYPTION by using IS_ENABLED and relying on static inline wrappers. A new static inline wrapper for setting sb->s_cop is introduced to allow filesystems to unconditionally compile in their s_cop operations. Signed-off-by: Sascha Hauer Signed-off-by: Richard Weinberger

fscrypt: cache decrypted symlink target in ->i_link

2019-04-17T16:43:29Z

Path lookups that traverse encrypted symlink(s) are very slow because each encrypted symlink needs to be decrypted each time it's followed. This also involves dropping out of rcu-walk mode. Make encrypted symlinks faster by caching the decrypted symlink target in ->i_link. The first call to fscrypt_get_symlink() sets it. Then, the existing VFS path lookup code uses the non-NULL ->i_link to take the fast path where ->get_link() isn't called, and lookups in rcu-walk mode remain in rcu-walk mode. Also set ->i_link immediately when a new encrypted symlink is created. To safely free the symlink target after an RCU grace period has elapsed, introduce a new function fscrypt_free_inode(), and make the relevant filesystems call it just before actually freeing the inode. Cc: Al Viro Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext

2019-04-17T14:07:51Z

->lookup() in an encrypted directory begins as follows: 1. fscrypt_prepare_lookup(): a. Try to load the directory's encryption key. b. If the key is unavailable, mark the dentry as a ciphertext name via d_flags. 2. fscrypt_setup_filename(): a. Try to load the directory's encryption key. b. If the key is available, encrypt the name (treated as a plaintext name) to get the on-disk name. Otherwise decode the name (treated as a ciphertext name) to get the on-disk name. But if the key is concurrently added, it may be found at (2a) but not at (1a). In this case, the dentry will be wrongly marked as a ciphertext name even though it was actually treated as plaintext. This will cause the dentry to be wrongly invalidated on the next lookup, potentially causing problems. For example, if the racy ->lookup() was part of sys_mount(), then the new mount will be detached when anything tries to access it. This is despite the mountpoint having a plaintext path, which should remain valid now that the key was added. Of course, this is only possible if there's a userspace race. Still, the additional kernel-side race is confusing and unexpected. Close the kernel-side race by changing fscrypt_prepare_lookup() to also set the on-disk filename (step 2b), consistent with the d_flags update. Fixes: 28b4c263961c ("ext4 crypto: revalidate dentry after adding or removing the key") Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o