Commit d74ba04d authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

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] f869e8a7 ("expose a low-level variant of fd_install() for binder")
[2] 44d8047f ("binder: use standard functions to allocate fds")
Acked-by: default avatarChristian 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: default avatarEric W. Biederman <ebiederm@xmission.com>
parent 775e0656

fs/file.c

+6 −19
Original line number Diff line number Diff line
@@ -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)

include/linux/fdtable.h

+0 −2
Original line number Diff line number Diff line
@@ -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);