[PATCH v8 3/5] fs: split off do_getxattr from getxattr

[Stefan Roesch <shr@fb.com>]

This splits off do_getxattr function from the getxattr
function. This will allow io_uring to call it from its
io worker.

Signed-off-by: Stefan Roesch <shr@fb.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
---
 fs/internal.h |  6 ++++++
 fs/xattr.c    | 32 ++++++++++++++++++++------------
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index b07df1623de6..420d0283be12 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -220,6 +220,12 @@ struct xattr_ctx {
 };
 
 
+ssize_t do_getxattr(struct user_namespace *mnt_userns,
+		    struct dentry *d,
+		    const char *kname,
+		    void __user *value,
+		    size_t size);
+
 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx,
 		void **xattr_val);
 int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
diff --git a/fs/xattr.c b/fs/xattr.c
index dcb4f0ff7e6e..51e305db426f 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -684,19 +684,12 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
 /*
  * Extended attribute GET operations
  */
-static ssize_t
-getxattr(struct user_namespace *mnt_userns, struct dentry *d,
-	 const char __user *name, void __user *value, size_t size)
+ssize_t
+do_getxattr(struct user_namespace *mnt_userns, struct dentry *d,
+	const char *kname, void __user *value, size_t size)
 {
-	ssize_t error;
 	void *kvalue = NULL;
-	char kname[XATTR_NAME_MAX + 1];
-
-	error = strncpy_from_user(kname, name, sizeof(kname));
-	if (error == 0 || error == sizeof(kname))
-		error = -ERANGE;
-	if (error < 0)
-		return error;
+	ssize_t error;
 
 	if (size) {
 		if (size > XATTR_SIZE_MAX)
@@ -720,10 +713,25 @@ getxattr(struct user_namespace *mnt_userns, struct dentry *d,
 	}
 
 	kvfree(kvalue);
-
 	return error;
 }
 
+static ssize_t
+getxattr(struct user_namespace *mnt_userns, struct dentry *d,
+	 const char __user *name, void __user *value, size_t size)
+{
+	ssize_t error;
+	struct xattr_name kname;
+
+	error = strncpy_from_user(kname.name, name, sizeof(kname.name));
+	if (error == 0 || error == sizeof(kname.name))
+		error = -ERANGE;
+	if (error < 0)
+		return error;
+
+	return do_getxattr(mnt_userns, d, kname.name, value, size);
+}
+
 static ssize_t path_getxattr(const char __user *pathname,
 			     const char __user *name, void __user *value,
 			     size_t size, unsigned int lookup_flags)
-- 
2.30.2