From: Eric Biggers <ebiggers@xxxxxxxxxx>
Make fsverity_prepare_setattr() an inline function that does the
IS_VERITY() check, then (if needed) calls __fsverity_prepare_setattr()
to do the real work. This reduces the overhead on non-verity files.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
fs/verity/open.c | 16 +++-------------
include/linux/fsverity.h | 26 ++++++++++++++++++++++----
2 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/fs/verity/open.c b/fs/verity/open.c
index 673d6db9abdf..e1e531d5e09a 100644
--- a/fs/verity/open.c
+++ b/fs/verity/open.c
@@ -337,26 +337,16 @@ int __fsverity_file_open(struct inode *inode, struct file *filp)
}
EXPORT_SYMBOL_GPL(__fsverity_file_open);
-/**
- * fsverity_prepare_setattr() - prepare to change a verity inode's attributes
- * @dentry: dentry through which the inode is being changed
- * @attr: attributes to change
- *
- * Verity files are immutable, so deny truncates. This isn't covered by the
- * open-time check because sys_truncate() takes a path, not a file descriptor.
- *
- * Return: 0 on success, -errno on failure
- */
-int fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr)
+int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr)
{
- if (IS_VERITY(d_inode(dentry)) && (attr->ia_valid & ATTR_SIZE)) {
+ if (attr->ia_valid & ATTR_SIZE) {
pr_debug("Denying truncate of verity file (ino %lu)\n",
d_inode(dentry)->i_ino);
return -EPERM;
}
return 0;
}
-EXPORT_SYMBOL_GPL(fsverity_prepare_setattr);
+EXPORT_SYMBOL_GPL(__fsverity_prepare_setattr);
/**
* fsverity_cleanup_inode() - free the inode's verity info, if present
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 326bf2e2b903..84b498fff7ec 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -149,7 +149,7 @@ int fsverity_get_digest(struct inode *inode,
/* open.c */
int __fsverity_file_open(struct inode *inode, struct file *filp);
-int fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr);
+int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr);
void fsverity_cleanup_inode(struct inode *inode);
/* read_metadata.c */
@@ -198,10 +198,10 @@ static inline int __fsverity_file_open(struct inode *inode, struct file *filp)
return -EOPNOTSUPP;
}
-static inline int fsverity_prepare_setattr(struct dentry *dentry,
- struct iattr *attr)
+static inline int __fsverity_prepare_setattr(struct dentry *dentry,
+ struct iattr *attr)
{
- return IS_VERITY(d_inode(dentry)) ? -EOPNOTSUPP : 0;
+ return -EOPNOTSUPP;
}
static inline void fsverity_cleanup_inode(struct inode *inode)
@@ -274,4 +274,22 @@ static inline int fsverity_file_open(struct inode *inode, struct file *filp)
return 0;
}
+/**
+ * fsverity_prepare_setattr() - prepare to change a verity inode's attributes
+ * @dentry: dentry through which the inode is being changed
+ * @attr: attributes to change
+ *
+ * Verity files are immutable, so deny truncates. This isn't covered by the
+ * open-time check because sys_truncate() takes a path, not a file descriptor.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static inline int fsverity_prepare_setattr(struct dentry *dentry,
+ struct iattr *attr)
+{
+ if (IS_VERITY(d_inode(dentry)))
+ return __fsverity_prepare_setattr(dentry, attr);
+ return 0;
+}
+
#endif /* _LINUX_FSVERITY_H */
--
2.38.1
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