file: Merge __fd_install into fd_install

The function __fd_install was added to support binder[1].  With binder
fixed[2] there are no more users.

As fd_install just calls __fd_install with "files=current->files",
merge them together by transforming the files parameter into a
local variable initialized to current->files.

[1] f869e8a7f753 ("expose a low-level variant of fd_install() for binder")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1:https://lkml.kernel.org/r/20200817220425.9389-14-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-18-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

diff --git a/fs/file.c b/fs/file.c
index 23b888a..0d4ec0f 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -158,7 +158,7 @@ static int expand_fdtable(struct files_struct *files, unsigned int nr)
        spin_unlock(&files->file_lock);
        new_fdt = alloc_fdtable(nr);
 
-       /* make sure all __fd_install() have seen resize_in_progress
+       /* make sure all fd_install() have seen resize_in_progress
         * or have finished their rcu_read_lock_sched() section.
         */
        if (atomic_read(&files->count) > 1)
@@ -181,7 +181,7 @@ static int expand_fdtable(struct files_struct *files, unsigned int nr)
        rcu_assign_pointer(files->fdt, new_fdt);
        if (cur_fdt != &files->fdtab)
                call_rcu(&cur_fdt->rcu, free_fdtable_rcu);
-       /* coupled with smp_rmb() in __fd_install() */
+       /* coupled with smp_rmb() in fd_install() */
        smp_wmb();
        return 1;
 }
@@ -584,17 +584,13 @@ EXPORT_SYMBOL(put_unused_fd);
  * It should never happen - if we allow dup2() do it, _really_ bad things
  * will follow.
  *
- * NOTE: __fd_install() variant is really, really low-level; don't
- * use it unless you are forced to by truly lousy API shoved down
- * your throat.  'files' *MUST* be either current->files or obtained
- * by get_files_struct(current) done by whoever had given it to you,
- * or really bad things will happen.  Normally you want to use
- * fd_install() instead.
+ * This consumes the "file" refcount, so callers should treat it
+ * as if they had called fput(file).
  */
 
-void __fd_install(struct files_struct *files, unsigned int fd,
-               struct file *file)
+void fd_install(unsigned int fd, struct file *file)
 {
+       struct files_struct *files = current->files;
        struct fdtable *fdt;
 
        rcu_read_lock_sched();
@@ -616,15 +612,6 @@ void __fd_install(struct files_struct *files, unsigned int fd,
        rcu_read_unlock_sched();
 }
 
-/*
- * This consumes the "file" refcount, so callers should treat it
- * as if they had called fput(file).
- */
-void fd_install(unsigned int fd, struct file *file)
-{
-       __fd_install(current->files, fd, file);
-}
-
 EXPORT_SYMBOL(fd_install);
 
 static struct file *pick_file(struct files_struct *files, unsigned fd)

diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index cf6c52d..a5ec736 100644 (file)
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -126,8 +126,6 @@ int iterate_fd(struct files_struct *, unsigned,
 
 extern int __alloc_fd(struct files_struct *files,
                      unsigned start, unsigned end, unsigned flags);
-extern void __fd_install(struct files_struct *files,
-                     unsigned int fd, struct file *file);
 extern int __close_fd(struct files_struct *files,
                      unsigned int fd);
 extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags);