file: Rename __close_fd to close_fd and remove the files parameter

The function __close_fd was added to support binder[1].  Now that
binder has been fixed to no longer need __close_fd[2] all calls
to __close_fd pass current->files.

Therefore transform the files parameter into a local variable
initialized to current->files, and rename __close_fd to close_fd to
reflect this change, and keep it in sync with the similar changes to
__alloc_fd, and __fd_install.

This removes the need for callers to care about the extra care that
needs to be take if anything except current->files is passed, by
limiting the callers to only operation on current->files.

[1] 483ce1d4b8c3 ("take descriptor-related part of close() to file.c")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-17-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-21-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

diff --git a/fs/file.c b/fs/file.c
index 6215637..987ea51 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -629,11 +629,9 @@ out_unlock:
        return file;
 }
 
-/*
- * The same warnings as for __alloc_fd()/__fd_install() apply here...
- */
-int __close_fd(struct files_struct *files, unsigned fd)
+int close_fd(unsigned fd)
 {
+       struct files_struct *files = current->files;
        struct file *file;
 
        file = pick_file(files, fd);
@@ -642,7 +640,7 @@ int __close_fd(struct files_struct *files, unsigned fd)
 
        return filp_close(file, files);
 }
-EXPORT_SYMBOL(__close_fd); /* for ksys_close() */
+EXPORT_SYMBOL(close_fd); /* for ksys_close() */
 
 /**
  * __close_range() - Close all file descriptors in a given range.
@@ -1027,7 +1025,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags)
        struct files_struct *files = current->files;
 
        if (!file)
-               return __close_fd(files, fd);
+               return close_fd(fd);
 
        if (fd >= rlimit(RLIMIT_NOFILE))
                return -EBADF;

diff --git a/fs/open.c b/fs/open.c
index 9af548f..581a674 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -1292,7 +1292,7 @@ EXPORT_SYMBOL(filp_close);
  */
 SYSCALL_DEFINE1(close, unsigned int, fd)
 {
-       int retval = __close_fd(current->files, fd);
+       int retval = close_fd(fd);
 
        /* can't restart close syscall because file table entry was cleared */
        if (unlikely(retval == -ERESTARTSYS ||

diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index dc476ae..dad4a48 100644 (file)
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -124,8 +124,7 @@ int iterate_fd(struct files_struct *, unsigned,
                int (*)(const void *, struct file *, unsigned),
                const void *);
 
-extern int __close_fd(struct files_struct *files,
-                     unsigned int fd);
+extern int close_fd(unsigned int fd);
 extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags);
 extern int __close_fd_get_file(unsigned int fd, struct file **res);
 extern int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 37bea07..9e055a0 100644 (file)
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1295,16 +1295,16 @@ static inline long ksys_ftruncate(unsigned int fd, loff_t length)
        return do_sys_ftruncate(fd, length, 1);
 }
 
-extern int __close_fd(struct files_struct *files, unsigned int fd);
+extern int close_fd(unsigned int fd);
 
 /*
  * In contrast to sys_close(), this stub does not check whether the syscall
  * should or should not be restarted, but returns the raw error codes from
- * __close_fd().
+ * close_fd().
  */
 static inline int ksys_close(unsigned int fd)
 {
-       return __close_fd(current->files, fd);
+       return close_fd(fd);
 }
 
 extern long do_sys_truncate(const char __user *pathname, loff_t length);