[PATCH 11/11] dup_fd(): change calling conventions

[Al Viro <viro@xxxxxxxxxxxxxxxxxx>]

return ERR_PTR() on failure, get rid of errorp

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
 fs/file.c               | 14 ++++----------
 include/linux/fdtable.h |  2 +-
 kernel/fork.c           | 26 ++++++++++++--------------
 3 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/fs/file.c b/fs/file.c
index 01cef75ef132..b8b5b615d116 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -306,17 +306,16 @@ static unsigned int sane_fdtable_size(struct fdtable *fdt, unsigned int max_fds)
  * passed in files structure.
  * errorp will be valid only when the returned files_struct is NULL.
  */
-struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds, int *errorp)
+struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds)
 {
 	struct files_struct *newf;
 	struct file **old_fds, **new_fds;
 	unsigned int open_files, i;
 	struct fdtable *old_fdt, *new_fdt;
 
-	*errorp = -ENOMEM;
 	newf = kmem_cache_alloc(files_cachep, GFP_KERNEL);
 	if (!newf)
-		goto out;
+		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&newf->count, 1);
 
@@ -346,8 +345,8 @@ struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds, int
 
 		new_fdt = alloc_fdtable(open_files);
 		if (IS_ERR(new_fdt)) {
-			*errorp = PTR_ERR(new_fdt);
-			goto out_release;
+			kmem_cache_free(files_cachep, newf);
+			return ERR_CAST(new_fdt);
 		}
 
 		/*
@@ -388,11 +387,6 @@ struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds, int
 	rcu_assign_pointer(newf->fdt, new_fdt);
 
 	return newf;
-
-out_release:
-	kmem_cache_free(files_cachep, newf);
-out:
-	return NULL;
 }
 
 static struct fdtable *close_files(struct files_struct * files)
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 42cadad89f99..b1a913a17d04 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -102,7 +102,7 @@ struct task_struct;
 
 void put_files_struct(struct files_struct *fs);
 int unshare_files(void);
-struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy;
+struct files_struct *dup_fd(struct files_struct *, unsigned) __latent_entropy;
 void do_close_on_exec(struct files_struct *);
 int iterate_fd(struct files_struct *, unsigned,
 		int (*)(const void *, struct file *, unsigned),
diff --git a/kernel/fork.c b/kernel/fork.c
index cc760491f201..67ab37db6400 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1754,33 +1754,30 @@ static int copy_files(unsigned long clone_flags, struct task_struct *tsk,
 		      int no_files)
 {
 	struct files_struct *oldf, *newf;
-	int error = 0;
 
 	/*
 	 * A background process may not have any files ...
 	 */
 	oldf = current->files;
 	if (!oldf)
-		goto out;
+		return 0;
 
 	if (no_files) {
 		tsk->files = NULL;
-		goto out;
+		return 0;
 	}
 
 	if (clone_flags & CLONE_FILES) {
 		atomic_inc(&oldf->count);
-		goto out;
+		return 0;
 	}
 
-	newf = dup_fd(oldf, NR_OPEN_MAX, &error);
-	if (!newf)
-		goto out;
+	newf = dup_fd(oldf, NR_OPEN_MAX);
+	if (IS_ERR(newf))
+		return PTR_ERR(newf);
 
 	tsk->files = newf;
-	error = 0;
-out:
-	return error;
+	return 0;
 }
 
 static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
@@ -3236,13 +3233,14 @@ int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,
 	       struct files_struct **new_fdp)
 {
 	struct files_struct *fd = current->files;
-	int error = 0;
 
 	if ((unshare_flags & CLONE_FILES) &&
 	    (fd && atomic_read(&fd->count) > 1)) {
-		*new_fdp = dup_fd(fd, max_fds, &error);
-		if (!*new_fdp)
-			return error;
+		*new_fdp = dup_fd(fd, max_fds);
+		if (IS_ERR(*new_fdp)) {
+			*new_fdp = NULL;
+			return PTR_ERR(new_fdp);
+		}
 	}
 
 	return 0;
-- 
2.39.2