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Message-Id: <20200917041136.178600-12-ebiggers@kernel.org>
Date: Wed, 16 Sep 2020 21:11:34 -0700
From: Eric Biggers <ebiggers@...nel.org>
To: linux-fscrypt@...r.kernel.org
Cc: linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
linux-mtd@...ts.infradead.org, ceph-devel@...r.kernel.org,
Jeff Layton <jlayton@...nel.org>,
Daniel Rosenberg <drosen@...gle.com>
Subject: [PATCH v3 11/13] fscrypt: move fscrypt_prepare_symlink() out-of-line
From: Eric Biggers <ebiggers@...gle.com>
In preparation for moving the logic for "get the encryption policy
inherited by new files in this directory" to a single place, make
fscrypt_prepare_symlink() a regular function rather than an inline
function that wraps __fscrypt_prepare_symlink().
This way, the new function fscrypt_policy_to_inherit() won't need to be
exported to filesystems.
Signed-off-by: Eric Biggers <ebiggers@...gle.com>
---
fs/crypto/hooks.c | 39 ++++++++++++++++++++++---
include/linux/fscrypt.h | 63 ++++++++++-------------------------------
2 files changed, 50 insertions(+), 52 deletions(-)
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 7748db5092409..a399c54947f28 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -166,12 +166,43 @@ int fscrypt_prepare_setflags(struct inode *inode,
return 0;
}
-int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
- unsigned int max_len,
- struct fscrypt_str *disk_link)
+/**
+ * fscrypt_prepare_symlink() - prepare to create a possibly-encrypted symlink
+ * @dir: directory in which the symlink is being created
+ * @target: plaintext symlink target
+ * @len: length of @target excluding null terminator
+ * @max_len: space the filesystem has available to store the symlink target
+ * @disk_link: (out) the on-disk symlink target being prepared
+ *
+ * This function computes the size the symlink target will require on-disk,
+ * stores it in @disk_link->len, and validates it against @max_len. An
+ * encrypted symlink may be longer than the original.
+ *
+ * Additionally, @disk_link->name is set to @target if the symlink will be
+ * unencrypted, but left NULL if the symlink will be encrypted. For encrypted
+ * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the
+ * on-disk target later. (The reason for the two-step process is that some
+ * filesystems need to know the size of the symlink target before creating the
+ * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.)
+ *
+ * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long,
+ * -ENOKEY if the encryption key is missing, or another -errno code if a problem
+ * occurred while setting up the encryption key.
+ */
+int fscrypt_prepare_symlink(struct inode *dir, const char *target,
+ unsigned int len, unsigned int max_len,
+ struct fscrypt_str *disk_link)
{
int err;
+ if (!IS_ENCRYPTED(dir) && !fscrypt_get_dummy_context(dir->i_sb)) {
+ disk_link->name = (unsigned char *)target;
+ disk_link->len = len + 1;
+ if (disk_link->len > max_len)
+ return -ENAMETOOLONG;
+ return 0;
+ }
+
/*
* To calculate the size of the encrypted symlink target we need to know
* the amount of NUL padding, which is determined by the flags set in
@@ -207,7 +238,7 @@ int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
disk_link->name = NULL;
return 0;
}
-EXPORT_SYMBOL_GPL(__fscrypt_prepare_symlink);
+EXPORT_SYMBOL_GPL(fscrypt_prepare_symlink);
int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
unsigned int len, struct fscrypt_str *disk_link)
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 81d6ded243288..39e7397a3f103 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -225,9 +225,9 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
struct fscrypt_name *fname);
int fscrypt_prepare_setflags(struct inode *inode,
unsigned int oldflags, unsigned int flags);
-int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
- unsigned int max_len,
- struct fscrypt_str *disk_link);
+int fscrypt_prepare_symlink(struct inode *dir, const char *target,
+ unsigned int len, unsigned int max_len,
+ struct fscrypt_str *disk_link);
int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
unsigned int len, struct fscrypt_str *disk_link);
const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
@@ -520,15 +520,21 @@ static inline int fscrypt_prepare_setflags(struct inode *inode,
return 0;
}
-static inline int __fscrypt_prepare_symlink(struct inode *dir,
- unsigned int len,
- unsigned int max_len,
- struct fscrypt_str *disk_link)
+static inline int fscrypt_prepare_symlink(struct inode *dir,
+ const char *target,
+ unsigned int len,
+ unsigned int max_len,
+ struct fscrypt_str *disk_link)
{
- return -EOPNOTSUPP;
+ if (IS_ENCRYPTED(dir))
+ return -EOPNOTSUPP;
+ disk_link->name = (unsigned char *)target;
+ disk_link->len = len + 1;
+ if (disk_link->len > max_len)
+ return -ENAMETOOLONG;
+ return 0;
}
-
static inline int __fscrypt_encrypt_symlink(struct inode *inode,
const char *target,
unsigned int len,
@@ -793,45 +799,6 @@ static inline int fscrypt_prepare_setattr(struct dentry *dentry,
return 0;
}
-/**
- * fscrypt_prepare_symlink() - prepare to create a possibly-encrypted symlink
- * @dir: directory in which the symlink is being created
- * @target: plaintext symlink target
- * @len: length of @target excluding null terminator
- * @max_len: space the filesystem has available to store the symlink target
- * @disk_link: (out) the on-disk symlink target being prepared
- *
- * This function computes the size the symlink target will require on-disk,
- * stores it in @disk_link->len, and validates it against @max_len. An
- * encrypted symlink may be longer than the original.
- *
- * Additionally, @disk_link->name is set to @target if the symlink will be
- * unencrypted, but left NULL if the symlink will be encrypted. For encrypted
- * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the
- * on-disk target later. (The reason for the two-step process is that some
- * filesystems need to know the size of the symlink target before creating the
- * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.)
- *
- * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long,
- * -ENOKEY if the encryption key is missing, or another -errno code if a problem
- * occurred while setting up the encryption key.
- */
-static inline int fscrypt_prepare_symlink(struct inode *dir,
- const char *target,
- unsigned int len,
- unsigned int max_len,
- struct fscrypt_str *disk_link)
-{
- if (IS_ENCRYPTED(dir) || fscrypt_get_dummy_context(dir->i_sb) != NULL)
- return __fscrypt_prepare_symlink(dir, len, max_len, disk_link);
-
- disk_link->name = (unsigned char *)target;
- disk_link->len = len + 1;
- if (disk_link->len > max_len)
- return -ENAMETOOLONG;
- return 0;
-}
-
/**
* fscrypt_encrypt_symlink() - encrypt the symlink target if needed
* @inode: symlink inode
--
2.28.0
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