diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2025-08-10 00:56:55 -0700 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-08-21 13:58:07 +0200 |
| commit | 93221de31a8df6710e02328f82dc68d7ab4ad9e6 (patch) | |
| tree | 58fb3fbe56a4672cee0f9db091dc651ca8bf8094 /include/linux/fscrypt.h | |
| parent | 6c9468aad215a198742c8375b0415e42521c905c (diff) | |
| download | lwn-93221de31a8df6710e02328f82dc68d7ab4ad9e6.tar.gz lwn-93221de31a8df6710e02328f82dc68d7ab4ad9e6.zip | |
fscrypt: add support for info in fs-specific part of inode
Add an inode_info_offs field to struct fscrypt_operations, and update
fs/crypto/ to support it. When set to a nonzero value, it specifies the
offset to the fscrypt_inode_info pointer within the filesystem-specific
part of the inode structure, to be used instead of inode::i_crypt_info.
Since this makes inode::i_crypt_info no longer necessarily used, update
comments that mentioned it.
This is a prerequisite for a later commit that removes
inode::i_crypt_info, saving memory and improving cache efficiency with
filesystems that don't support fscrypt.
Co-developed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/20250810075706.172910-3-ebiggers@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/linux/fscrypt.h')
| -rw-r--r-- | include/linux/fscrypt.h | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 23c5198612d1..d7ff53accbfe 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -61,6 +61,12 @@ struct fscrypt_name { /* Crypto operations for filesystems */ struct fscrypt_operations { + /* + * The offset of the pointer to struct fscrypt_inode_info in the + * filesystem-specific part of the inode, relative to the beginning of + * the common part of the inode (the 'struct inode'). + */ + ptrdiff_t inode_info_offs; /* * If set, then fs/crypto/ will allocate a global bounce page pool the @@ -195,6 +201,14 @@ struct fscrypt_operations { int fscrypt_d_revalidate(struct inode *dir, const struct qstr *name, struct dentry *dentry, unsigned int flags); +static inline struct fscrypt_inode_info ** +fscrypt_inode_info_addr(const struct inode *inode) +{ + if (inode->i_sb->s_cop->inode_info_offs == 0) + return (struct fscrypt_inode_info **)&inode->i_crypt_info; + return (void *)inode + inode->i_sb->s_cop->inode_info_offs; +} + /* * Load the inode's fscrypt info pointer, using a raw dereference. Since this * uses a raw dereference with no memory barrier, it is appropriate to use only @@ -205,7 +219,7 @@ int fscrypt_d_revalidate(struct inode *dir, const struct qstr *name, static inline struct fscrypt_inode_info * fscrypt_get_inode_info_raw(const struct inode *inode) { - struct fscrypt_inode_info *ci = inode->i_crypt_info; + struct fscrypt_inode_info *ci = *fscrypt_inode_info_addr(inode); VFS_WARN_ON_ONCE(ci == NULL); return ci; @@ -216,11 +230,11 @@ fscrypt_get_inode_info(const struct inode *inode) { /* * Pairs with the cmpxchg_release() in fscrypt_setup_encryption_info(). - * I.e., another task may publish ->i_crypt_info concurrently, executing - * a RELEASE barrier. We need to use smp_load_acquire() here to safely + * I.e., another task may publish the fscrypt info concurrently, + * executing a RELEASE barrier. Use smp_load_acquire() here to safely * ACQUIRE the memory the other task published. */ - return smp_load_acquire(&inode->i_crypt_info); + return smp_load_acquire(fscrypt_inode_info_addr(inode)); } /** |