diff mbox series

[v4,1/6] fs: make do_mkdirat() take struct filename

Message ID 20210513110612.688851-2-dkadashev@gmail.com (mailing list archive)
State New, archived
Headers show
Series io_uring: add mkdirat support | expand

Commit Message

Dmitry Kadashev May 13, 2021, 11:06 a.m. UTC 
Pass in the struct filename pointers instead of the user string, and
update the three callers to do the same. This is heavily based on
commit dbea8d345177 ("fs: make do_renameat2() take struct filename").

This behaves like do_unlinkat() and do_renameat2().

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/internal.h |  1 +
 fs/namei.c    | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

Comments

Christian Brauner May 14, 2021, 2:32 p.m. UTC | #1 
On Thu, May 13, 2021 at 06:06:07PM +0700, Dmitry Kadashev wrote:
> Pass in the struct filename pointers instead of the user string, and
> update the three callers to do the same. This is heavily based on
> commit dbea8d345177 ("fs: make do_renameat2() take struct filename").
> 
> This behaves like do_unlinkat() and do_renameat2().
> 
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
> ---

Independent of the following patches I think this is ok and with
do_renameat2() that form of conversion has precedence.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>

>  fs/internal.h |  1 +
>  fs/namei.c    | 22 ++++++++++++++++------
>  2 files changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/internal.h b/fs/internal.h
> index 6aeae7ef3380..848e165ef0f1 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -77,6 +77,7 @@ long do_unlinkat(int dfd, struct filename *name);
>  int may_linkat(struct user_namespace *mnt_userns, struct path *link);
>  int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
>  		 struct filename *newname, unsigned int flags);
> +long do_mkdirat(int dfd, struct filename *name, umode_t mode);

(We should probably have all helpers just return either long or int
instead of alternating between long and int.)
Dmitry Kadashev May 17, 2021, 9:48 a.m. UTC | #2 
On Fri, May 14, 2021 at 9:32 PM Christian Brauner
<christian.brauner@ubuntu.com> wrote:
>
> (We should probably have all helpers just return either long or int
> instead of alternating between long and int.)

Looks like all the helpers are using int internally, and syscalls using
these helpers return int as well. So I will add a patch to make all of
them return ints.

--
Dmitry Kadashev
diff mbox series

Patch

diff --git a/fs/internal.h b/fs/internal.h
index 6aeae7ef3380..848e165ef0f1 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -77,6 +77,7 @@  long do_unlinkat(int dfd, struct filename *name);
 int may_linkat(struct user_namespace *mnt_userns, struct path *link);
 int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
 		 struct filename *newname, unsigned int flags);
+long do_mkdirat(int dfd, struct filename *name, umode_t mode);
 
 /*
  * namespace.c
diff --git a/fs/namei.c b/fs/namei.c
index 79b0ff9b151e..49317c018341 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3556,7 +3556,7 @@  struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
 	return file;
 }
 
-static struct dentry *filename_create(int dfd, struct filename *name,
+static struct dentry *__filename_create(int dfd, struct filename *name,
 				struct path *path, unsigned int lookup_flags)
 {
 	struct dentry *dentry = ERR_PTR(-EEXIST);
@@ -3612,7 +3612,6 @@  static struct dentry *filename_create(int dfd, struct filename *name,
 		error = err2;
 		goto fail;
 	}
-	putname(name);
 	return dentry;
 fail:
 	dput(dentry);
@@ -3627,6 +3626,16 @@  static struct dentry *filename_create(int dfd, struct filename *name,
 	return dentry;
 }
 
+static inline struct dentry *filename_create(int dfd, struct filename *name,
+				struct path *path, unsigned int lookup_flags)
+{
+	struct dentry *res = __filename_create(dfd, name, path, lookup_flags);
+
+	if (!IS_ERR(res))
+		putname(name);
+	return res;
+}
+
 struct dentry *kern_path_create(int dfd, const char *pathname,
 				struct path *path, unsigned int lookup_flags)
 {
@@ -3817,7 +3826,7 @@  int vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 }
 EXPORT_SYMBOL(vfs_mkdir);
 
-static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
+long do_mkdirat(int dfd, struct filename *name, umode_t mode)
 {
 	struct dentry *dentry;
 	struct path path;
@@ -3825,7 +3834,7 @@  static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
 	unsigned int lookup_flags = LOOKUP_DIRECTORY;
 
 retry:
-	dentry = user_path_create(dfd, pathname, &path, lookup_flags);
+	dentry = __filename_create(dfd, name, &path, lookup_flags);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
@@ -3843,17 +3852,18 @@  static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
 	}
+	putname(name);
 	return error;
 }
 
 SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
 {
-	return do_mkdirat(dfd, pathname, mode);
+	return do_mkdirat(dfd, getname(pathname), mode);
 }
 
 SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 {
-	return do_mkdirat(AT_FDCWD, pathname, mode);
+	return do_mkdirat(AT_FDCWD, getname(pathname), mode);
 }
 
 /**