Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...

Pull fscrypt updates from Ted Ts'o:
 "Lots of cleanups, mostly courtesy by Eric Biggers"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: lock mutex before checking for bounce page pool
  fscrypt: add a documentation file for filesystem-level encryption
  ext4: switch to fscrypt_prepare_setattr()
  ext4: switch to fscrypt_prepare_lookup()
  ext4: switch to fscrypt_prepare_rename()
  ext4: switch to fscrypt_prepare_link()
  ext4: switch to fscrypt_file_open()
  fscrypt: new helper function - fscrypt_prepare_setattr()
  fscrypt: new helper function - fscrypt_prepare_lookup()
  fscrypt: new helper function - fscrypt_prepare_rename()
  fscrypt: new helper function - fscrypt_prepare_link()
  fscrypt: new helper function - fscrypt_file_open()
  fscrypt: new helper function - fscrypt_require_key()
  fscrypt: remove unneeded empty fscrypt_operations structs
  fscrypt: remove ->is_encrypted()
  fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED()
  fs, fscrypt: add an S_ENCRYPTED inode flag
  fscrypt: clean up include file mess

diff --cc MAINTAINERS
Simple merge

diff --cc fs/crypto/crypto.c
Simple merge

diff --cc fs/crypto/fname.c
Simple merge

diff --cc fs/crypto/fscrypt_private.h
Simple merge

diff --cc fs/crypto/keyinfo.c
Simple merge

diff --cc fs/crypto/policy.c
Simple merge

diff --cc fs/ext4/ext4.h
Simple merge

diff --cc fs/ext4/file.c
Simple merge

diff --cc fs/ext4/inode.c
Simple merge

diff --cc fs/ext4/namei.c
Simple merge

diff --cc fs/ext4/super.c
Simple merge

diff --cc fs/f2fs/f2fs.h
Simple merge

diff --cc fs/f2fs/super.c
Simple merge

diff --cc fs/ubifs/crypto.c
Simple merge

diff --cc include/linux/fs.h
Simple merge

diff --cc include/linux/fscrypt.h
index 0000000,53437bf..08b4b40
mode 000000,100644..100644
--- /dev/null
--- 2/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@@ -1,0 -1,293 +1,294 @@@
++/* SPDX-License-Identifier: GPL-2.0 */
+ /*
+  * fscrypt.h: declarations for per-file encryption
+  *
+  * Filesystems that implement per-file encryption include this header
+  * file with the __FS_HAS_ENCRYPTION set according to whether that filesystem
+  * is being built with encryption support or not.
+  *
+  * Copyright (C) 2015, Google, Inc.
+  *
+  * Written by Michael Halcrow, 2015.
+  * Modified by Jaegeuk Kim, 2015.
+  */
+ #ifndef _LINUX_FSCRYPT_H
+ #define _LINUX_FSCRYPT_H
+ 
+ #include <linux/key.h>
+ #include <linux/fs.h>
+ #include <linux/mm.h>
+ #include <linux/bio.h>
+ #include <linux/dcache.h>
+ #include <crypto/skcipher.h>
+ #include <uapi/linux/fs.h>
+ 
+ #define FS_CRYPTO_BLOCK_SIZE          16
+ 
+ struct fscrypt_info;
+ 
+ struct fscrypt_ctx {
+       union {
+               struct {
+                       struct page *bounce_page;       /* Ciphertext page */
+                       struct page *control_page;      /* Original page  */
+               } w;
+               struct {
+                       struct bio *bio;
+                       struct work_struct work;
+               } r;
+               struct list_head free_list;     /* Free list */
+       };
+       u8 flags;                               /* Flags */
+ };
+ 
+ /**
+  * For encrypted symlinks, the ciphertext length is stored at the beginning
+  * of the string in little-endian format.
+  */
+ struct fscrypt_symlink_data {
+       __le16 len;
+       char encrypted_path[1];
+ } __packed;
+ 
+ struct fscrypt_str {
+       unsigned char *name;
+       u32 len;
+ };
+ 
+ struct fscrypt_name {
+       const struct qstr *usr_fname;
+       struct fscrypt_str disk_name;
+       u32 hash;
+       u32 minor_hash;
+       struct fscrypt_str crypto_buf;
+ };
+ 
+ #define FSTR_INIT(n, l)               { .name = n, .len = l }
+ #define FSTR_TO_QSTR(f)               QSTR_INIT((f)->name, (f)->len)
+ #define fname_name(p)         ((p)->disk_name.name)
+ #define fname_len(p)          ((p)->disk_name.len)
+ 
+ /*
+  * fscrypt superblock flags
+  */
+ #define FS_CFLG_OWN_PAGES (1U << 1)
+ 
+ /*
+  * crypto opertions for filesystems
+  */
+ struct fscrypt_operations {
+       unsigned int flags;
+       const char *key_prefix;
+       int (*get_context)(struct inode *, void *, size_t);
+       int (*set_context)(struct inode *, const void *, size_t, void *);
+       bool (*dummy_context)(struct inode *);
+       bool (*empty_dir)(struct inode *);
+       unsigned (*max_namelen)(struct inode *);
+ };
+ 
+ /* Maximum value for the third parameter of fscrypt_operations.set_context(). */
+ #define FSCRYPT_SET_CONTEXT_MAX_SIZE  28
+ 
+ static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
+ {
+       if (inode->i_sb->s_cop->dummy_context &&
+                               inode->i_sb->s_cop->dummy_context(inode))
+               return true;
+       return false;
+ }
+ 
+ static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
+                                       u32 filenames_mode)
+ {
+       if (contents_mode == FS_ENCRYPTION_MODE_AES_128_CBC &&
+           filenames_mode == FS_ENCRYPTION_MODE_AES_128_CTS)
+               return true;
+ 
+       if (contents_mode == FS_ENCRYPTION_MODE_AES_256_XTS &&
+           filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS)
+               return true;
+ 
+       return false;
+ }
+ 
+ static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
+ {
+       if (str->len == 1 && str->name[0] == '.')
+               return true;
+ 
+       if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
+               return true;
+ 
+       return false;
+ }
+ 
+ #if __FS_HAS_ENCRYPTION
+ 
+ static inline struct page *fscrypt_control_page(struct page *page)
+ {
+       return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
+ }
+ 
+ static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+ {
+       return (inode->i_crypt_info != NULL);
+ }
+ 
+ #include <linux/fscrypt_supp.h>
+ 
+ #else /* !__FS_HAS_ENCRYPTION */
+ 
+ static inline struct page *fscrypt_control_page(struct page *page)
+ {
+       WARN_ON_ONCE(1);
+       return ERR_PTR(-EINVAL);
+ }
+ 
+ static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+ {
+       return 0;
+ }
+ 
+ #include <linux/fscrypt_notsupp.h>
+ #endif /* __FS_HAS_ENCRYPTION */
+ 
+ /**
+  * fscrypt_require_key - require an inode's encryption key
+  * @inode: the inode we need the key for
+  *
+  * If the inode is encrypted, set up its encryption key if not already done.
+  * Then require that the key be present and return -ENOKEY otherwise.
+  *
+  * No locks are needed, and the key will live as long as the struct inode --- so
+  * it won't go away from under you.
+  *
+  * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
+  * if a problem occurred while setting up the encryption key.
+  */
+ static inline int fscrypt_require_key(struct inode *inode)
+ {
+       if (IS_ENCRYPTED(inode)) {
+               int err = fscrypt_get_encryption_info(inode);
+ 
+               if (err)
+                       return err;
+               if (!fscrypt_has_encryption_key(inode))
+                       return -ENOKEY;
+       }
+       return 0;
+ }
+ 
+ /**
+  * fscrypt_prepare_link - prepare to link an inode into a possibly-encrypted directory
+  * @old_dentry: an existing dentry for the inode being linked
+  * @dir: the target directory
+  * @dentry: negative dentry for the target filename
+  *
+  * A new link can only be added to an encrypted directory if the directory's
+  * encryption key is available --- since otherwise we'd have no way to encrypt
+  * the filename.  Therefore, we first set up the directory's encryption key (if
+  * not already done) and return an error if it's unavailable.
+  *
+  * We also verify that the link will not violate the constraint that all files
+  * in an encrypted directory tree use the same encryption policy.
+  *
+  * Return: 0 on success, -ENOKEY if the directory's encryption key is missing,
+  * -EPERM if the link would result in an inconsistent encryption policy, or
+  * another -errno code.
+  */
+ static inline int fscrypt_prepare_link(struct dentry *old_dentry,
+                                      struct inode *dir,
+                                      struct dentry *dentry)
+ {
+       if (IS_ENCRYPTED(dir))
+               return __fscrypt_prepare_link(d_inode(old_dentry), dir);
+       return 0;
+ }
+ 
+ /**
+  * fscrypt_prepare_rename - prepare for a rename between possibly-encrypted directories
+  * @old_dir: source directory
+  * @old_dentry: dentry for source file
+  * @new_dir: target directory
+  * @new_dentry: dentry for target location (may be negative unless exchanging)
+  * @flags: rename flags (we care at least about %RENAME_EXCHANGE)
+  *
+  * Prepare for ->rename() where the source and/or target directories may be
+  * encrypted.  A new link can only be added to an encrypted directory if the
+  * directory's encryption key is available --- since otherwise we'd have no way
+  * to encrypt the filename.  A rename to an existing name, on the other hand,
+  * *is* cryptographically possible without the key.  However, we take the more
+  * conservative approach and just forbid all no-key renames.
+  *
+  * We also verify that the rename will not violate the constraint that all files
+  * in an encrypted directory tree use the same encryption policy.
+  *
+  * Return: 0 on success, -ENOKEY if an encryption key is missing, -EPERM if the
+  * rename would cause inconsistent encryption policies, or another -errno code.
+  */
+ static inline int fscrypt_prepare_rename(struct inode *old_dir,
+                                        struct dentry *old_dentry,
+                                        struct inode *new_dir,
+                                        struct dentry *new_dentry,
+                                        unsigned int flags)
+ {
+       if (IS_ENCRYPTED(old_dir) || IS_ENCRYPTED(new_dir))
+               return __fscrypt_prepare_rename(old_dir, old_dentry,
+                                               new_dir, new_dentry, flags);
+       return 0;
+ }
+ 
+ /**
+  * fscrypt_prepare_lookup - prepare to lookup a name in a possibly-encrypted directory
+  * @dir: directory being searched
+  * @dentry: filename being looked up
+  * @flags: lookup flags
+  *
+  * Prepare for ->lookup() in a directory which may be encrypted.  Lookups can be
+  * done with or without the directory's encryption key; without the key,
+  * filenames are presented in encrypted form.  Therefore, we'll try to set up
+  * the directory's encryption key, but even without it the lookup can continue.
+  *
+  * To allow invalidating stale dentries if the directory's encryption key is
+  * added later, we also install a custom ->d_revalidate() method and use the
+  * DCACHE_ENCRYPTED_WITH_KEY flag to indicate whether a given dentry is a
+  * plaintext name (flag set) or a ciphertext name (flag cleared).
+  *
+  * Return: 0 on success, -errno if a problem occurred while setting up the
+  * encryption key
+  */
+ static inline int fscrypt_prepare_lookup(struct inode *dir,
+                                        struct dentry *dentry,
+                                        unsigned int flags)
+ {
+       if (IS_ENCRYPTED(dir))
+               return __fscrypt_prepare_lookup(dir, dentry);
+       return 0;
+ }
+ 
+ /**
+  * fscrypt_prepare_setattr - prepare to change a possibly-encrypted inode's attributes
+  * @dentry: dentry through which the inode is being changed
+  * @attr: attributes to change
+  *
+  * Prepare for ->setattr() on a possibly-encrypted inode.  On an encrypted file,
+  * most attribute changes are allowed even without the encryption key.  However,
+  * without the encryption key we do have to forbid truncates.  This is needed
+  * because the size being truncated to may not be a multiple of the filesystem
+  * block size, and in that case we'd have to decrypt the final block, zero the
+  * portion past i_size, and re-encrypt it.  (We *could* allow truncating to a
+  * filesystem block boundary, but it's simpler to just forbid all truncates ---
+  * and we already forbid all other contents modifications without the key.)
+  *
+  * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
+  * if a problem occurred while setting up the encryption key.
+  */
+ static inline int fscrypt_prepare_setattr(struct dentry *dentry,
+                                         struct iattr *attr)
+ {
+       if (attr->ia_valid & ATTR_SIZE)
+               return fscrypt_require_key(d_inode(dentry));
+       return 0;
+ }
+ 
+ #endif        /* _LINUX_FSCRYPT_H */

diff --cc include/linux/fscrypt_notsupp.h
Simple merge

diff --cc include/linux/fscrypt_supp.h
Simple merge