fs: remove do_sys_truncate

do_sys_truncate ist only used to implement ksys_truncate and the native
truncate syscalls.  Merge do_sys_truncate into ksys_truncate and return
int from it as it only returns 0 or negative errnos.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260323070205.2939118-4-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: Christoph Hellwig

fs/open.c

@@ -126,7 +126,7 @@ int vfs_truncate(const struct path *path, loff_t length)
 }
 EXPORT_SYMBOL_GPL(vfs_truncate);
 
-int do_sys_truncate(const char __user *pathname, loff_t length)
+int ksys_truncate(const char __user *pathname, loff_t length)
 {
 	unsigned int lookup_flags = LOOKUP_FOLLOW;
 	struct path path;
@@ -151,13 +151,13 @@ int do_sys_truncate(const char __user *pathname, loff_t length)
 
 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
 {
-	return do_sys_truncate(path, length);
+	return ksys_truncate(path, length);
 }
 
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
 {
-	return do_sys_truncate(path, length);
+	return ksys_truncate(path, length);
 }
 #endif
 
@@ -222,7 +222,7 @@ COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_off_t, length)
 #if BITS_PER_LONG == 32
 SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
 {
-	return do_sys_truncate(path, length);
+	return ksys_truncate(path, length);
 }
 
 SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)

include/linux/syscalls.h

@@ -1285,13 +1285,7 @@ static inline long ksys_lchown(const char __user *filename, uid_t user,
 
 #define FTRUNCATE_LFS	(1u << 0)	/* allow truncating > 32-bit */
 int ksys_ftruncate(unsigned int fd, loff_t length, unsigned int flags);
-
-int do_sys_truncate(const char __user *pathname, loff_t length);
-
-static inline long ksys_truncate(const char __user *pathname, loff_t length)
-{
-	return do_sys_truncate(pathname, length);
-}
+int ksys_truncate(const char __user *pathname, loff_t length);
 
 static inline unsigned int ksys_personality(unsigned int personality)
 {