diff mbox series

[RFC,1/2] fs: split off vfs_getdents function of getdents64 syscall

Message ID 20230422-uring-getdents-v1-1-14c1db36e98c@codewreck.org (mailing list archive)
State Mainlined, archived
Headers show
Series io_uring: add getdents support, take 2 | expand

Commit Message

Dominique Martinet April 22, 2023, 8:40 a.m. UTC
This splits off the vfs_getdents function from the getdents64 system
call.
This will allow io_uring to call the vfs_getdents function.

Co-authored-by: Stefan Roesch <shr@fb.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
---
 fs/internal.h |  8 ++++++++
 fs/readdir.c  | 33 +++++++++++++++++++++++++--------
 2 files changed, 33 insertions(+), 8 deletions(-)

Comments

Dominique Martinet April 22, 2023, 10:34 a.m. UTC | #1
Dominique Martinet wrote on Sat, Apr 22, 2023 at 05:40:18PM +0900:
> This splits off the vfs_getdents function from the getdents64 system
> call.
> This will allow io_uring to call the vfs_getdents function.
> 
> Co-authored-by: Stefan Roesch <shr@fb.com>
> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
> ---
>  fs/internal.h |  8 ++++++++
>  fs/readdir.c  | 33 +++++++++++++++++++++++++--------
>  2 files changed, 33 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/internal.h b/fs/internal.h
> index dc4eb91a577a..92eeaf3837d1 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -264,3 +264,11 @@ int setattr_should_drop_sgid(struct mnt_idmap *idmap,
>  struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
>  struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
>  void mnt_idmap_put(struct mnt_idmap *idmap);
> +
> +/*
> + * fs/readdir.c
> + */
> +struct linux_dirent64;
> +
> +int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent,
> +		 unsigned int count);
> diff --git a/fs/readdir.c b/fs/readdir.c
> index 9c53edb60c03..1d541a6f2d55 100644
> --- a/fs/readdir.c
> +++ b/fs/readdir.c

(This needs an extra `#include "internal.h"`, missing declaration
warning reported privately by intel build robot... fs/ doesn't build
with W=1 by default; I'll resend v2 after some comments it doesn't make
much sense to spam patches at this point)

--
Dominique
diff mbox series

Patch

diff --git a/fs/internal.h b/fs/internal.h
index dc4eb91a577a..92eeaf3837d1 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -264,3 +264,11 @@  int setattr_should_drop_sgid(struct mnt_idmap *idmap,
 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
 void mnt_idmap_put(struct mnt_idmap *idmap);
+
+/*
+ * fs/readdir.c
+ */
+struct linux_dirent64;
+
+int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent,
+		 unsigned int count);
diff --git a/fs/readdir.c b/fs/readdir.c
index 9c53edb60c03..1d541a6f2d55 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -351,10 +351,16 @@  static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
 	return false;
 }
 
-SYSCALL_DEFINE3(getdents64, unsigned int, fd,
-		struct linux_dirent64 __user *, dirent, unsigned int, count)
+
+/**
+ * vfs_getdents - getdents without fdget
+ * @file    : pointer to file struct of directory
+ * @dirent  : pointer to user directory structure
+ * @count   : size of buffer
+ */
+int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent,
+		 unsigned int count)
 {
-	struct fd f;
 	struct getdents_callback64 buf = {
 		.ctx.actor = filldir64,
 		.count = count,
@@ -362,11 +368,7 @@  SYSCALL_DEFINE3(getdents64, unsigned int, fd,
 	};
 	int error;
 
-	f = fdget_pos(fd);
-	if (!f.file)
-		return -EBADF;
-
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
 	if (buf.prev_reclen) {
@@ -379,6 +381,21 @@  SYSCALL_DEFINE3(getdents64, unsigned int, fd,
 		else
 			error = count - buf.count;
 	}
+	return error;
+}
+
+SYSCALL_DEFINE3(getdents64, unsigned int, fd,
+		struct linux_dirent64 __user *, dirent, unsigned int, count)
+{
+	struct fd f;
+	int error;
+
+	f = fdget_pos(fd);
+	if (!f.file)
+		return -EBADF;
+
+	error = vfs_getdents(f.file, dirent, count);
+
 	fdput_pos(f);
 	return error;
 }