5.10-stable review patch. If anyone has any objections, please let me know.
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From: Eric W. Biederman ebiederm@xmission.com
[ Upstream commit d74ba04d919ebe30bf47406819c18c6b50003d92 ]
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 Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/file.c | 25 ++++++------------------- include/linux/fdtable.h | 2 -- 2 files changed, 6 insertions(+), 21 deletions(-)
diff --git a/fs/file.c b/fs/file.c index 9fa49e6298fba..a80deabe7f7dc 100644 --- a/fs/file.c +++ b/fs/file.c @@ -175,7 +175,7 @@ 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) @@ -198,7 +198,7 @@ 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; } @@ -613,17 +613,13 @@ 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(); @@ -645,15 +641,6 @@ 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 b0c6a959c6a00..6e8743a4c9d31 100644 --- 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);