[PATCH 0/2] io_uring: add mkdirat support

[PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

This adds mkdirat support to io_uring and is heavily based on recently
added renameat() / unlinkat() support.

The first patch is preparation with no functional changes, makes
do_mkdirat accept struct filename pointer rather than the user string.

The second one leverages that to implement mkdirat in io_uring.

Based on for-5.11/io_uring.

Dmitry Kadashev (2):
  fs: make do_mkdirat() take struct filename
  io_uring: add support for IORING_OP_MKDIRAT

 fs/internal.h                 |  1 +
 fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
 fs/namei.c                    | 20 ++++++++----
 include/uapi/linux/io_uring.h |  1 +
 4 files changed, 74 insertions(+), 6 deletions(-)

-- 
2.28.0

[PATCH 1/2] fs: make do_mkdirat() take struct filename

[Dmitry Kadashev]

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().

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/internal.h |  1 +
 fs/namei.c    | 20 ++++++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 6fd14ea213c3..23b8b427dbd2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -80,6 +80,7 @@ long do_unlinkat(int dfd, struct filename *name);
 int may_linkat(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 03d0e11e4f36..9d26a51f3f54 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3654,17 +3654,23 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 }
 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;
 	int error;
 	unsigned int lookup_flags = LOOKUP_DIRECTORY;
 
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+
 retry:
-	dentry = user_path_create(dfd, pathname, &path, lookup_flags);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
+	name->refcnt++; /* filename_create() drops our ref */
+	dentry = filename_create(dfd, name, &path, lookup_flags);
+	if (IS_ERR(dentry)) {
+		error = PTR_ERR(dentry);
+		goto out;
+	}
 
 	if (!IS_POSIXACL(path.dentry->d_inode))
 		mode &= ~current_umask();
@@ -3676,17 +3682,19 @@ static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
 	}
+out:
+	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);
 }
 
 int vfs_rmdir(struct inode *dir, struct dentry *dentry)
-- 
2.28.0

[PATCH 2/2] io_uring: add support for IORING_OP_MKDIRAT

[Dmitry Kadashev]

IORING_OP_MKDIRAT behaves like mkdirat(2) and takes the same flags
and arguments.

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/io_uring.h |  1 +
 2 files changed, 59 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 365a583033c5..0848b6c18fa6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -565,6 +565,13 @@ struct io_unlink {
 	struct filename			*filename;
 };
 
+struct io_mkdir {
+	struct file			*file;
+	int				dfd;
+	umode_t				mode;
+	struct filename			*filename;
+};
+
 struct io_completion {
 	struct file			*file;
 	struct list_head		list;
@@ -692,6 +699,7 @@ struct io_kiocb {
 		struct io_shutdown	shutdown;
 		struct io_rename	rename;
 		struct io_unlink	unlink;
+		struct io_mkdir		mkdir;
 		/* use only after cleaning per-op data, see io_clean_op() */
 		struct io_completion	compl;
 	};
@@ -979,6 +987,10 @@ static const struct io_op_def io_op_defs[] = {
 		.work_flags		= IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
 						IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
 	},
+	[IORING_OP_MKDIRAT] = {
+		.work_flags		= IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
+						IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
+	},
 };
 
 enum io_mem_account {
@@ -3745,6 +3757,44 @@ static int io_unlinkat(struct io_kiocb *req, bool force_nonblock)
 	return 0;
 }
 
+static int io_mkdirat_prep(struct io_kiocb *req,
+			    const struct io_uring_sqe *sqe)
+{
+	struct io_mkdir *mkd = &req->mkdir;
+	const char __user *fname;
+
+	if (unlikely(req->flags & REQ_F_FIXED_FILE))
+		return -EBADF;
+
+	mkd->dfd = READ_ONCE(sqe->fd);
+	mkd->mode = READ_ONCE(sqe->len);
+
+	fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	mkd->filename = getname(fname);
+	if (IS_ERR(mkd->filename))
+		return PTR_ERR(mkd->filename);
+
+	req->flags |= REQ_F_NEED_CLEANUP;
+	return 0;
+}
+
+static int io_mkdirat(struct io_kiocb *req, bool force_nonblock)
+{
+	struct io_mkdir *mkd = &req->mkdir;
+	int ret;
+
+	if (force_nonblock)
+		return -EAGAIN;
+
+	ret = do_mkdirat(mkd->dfd, mkd->filename, mkd->mode);
+
+	req->flags &= ~REQ_F_NEED_CLEANUP;
+	if (ret < 0)
+		req_set_fail_links(req);
+	io_req_complete(req, ret);
+	return 0;
+}
+
 static int io_shutdown_prep(struct io_kiocb *req,
 			    const struct io_uring_sqe *sqe)
 {
@@ -5956,6 +6006,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 		return io_renameat_prep(req, sqe);
 	case IORING_OP_UNLINKAT:
 		return io_unlinkat_prep(req, sqe);
+	case IORING_OP_MKDIRAT:
+		return io_mkdirat_prep(req, sqe);
 	}
 
 	printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -6099,6 +6151,9 @@ static void __io_clean_op(struct io_kiocb *req)
 		case IORING_OP_UNLINKAT:
 			putname(req->unlink.filename);
 			break;
+		case IORING_OP_MKDIRAT:
+			putname(req->mkdir.filename);
+			break;
 		}
 		req->flags &= ~REQ_F_NEED_CLEANUP;
 	}
@@ -6214,6 +6269,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
 	case IORING_OP_UNLINKAT:
 		ret = io_unlinkat(req, force_nonblock);
 		break;
+	case IORING_OP_MKDIRAT:
+		ret = io_mkdirat(req, force_nonblock);
+		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 6bb8229de892..bc256eab7809 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -137,6 +137,7 @@ enum {
 	IORING_OP_SHUTDOWN,
 	IORING_OP_RENAMEAT,
 	IORING_OP_UNLINKAT,
+	IORING_OP_MKDIRAT,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.28.0

Re: [PATCH 0/2] io_uring: add mkdirat support

[Jens Axboe]

On 11/11/20 6:25 AM, Dmitry Kadashev wrote:
> This adds mkdirat support to io_uring and is heavily based on recently
> added renameat() / unlinkat() support.
> 
> The first patch is preparation with no functional changes, makes
> do_mkdirat accept struct filename pointer rather than the user string.
> 
> The second one leverages that to implement mkdirat in io_uring.

Looks good to me - you should send the first patch to linux-fsdevel (and
CC Al Viro), really needs to be acked on that side before it can go in.

Also, have you written some test cases?

-- 
Jens Axboe

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Fri, Nov 13, 2020 at 04:57:13PM -0700, Jens Axboe wrote:
> On 11/11/20 6:25 AM, Dmitry Kadashev wrote:
> > This adds mkdirat support to io_uring and is heavily based on recently
> > added renameat() / unlinkat() support.
> > 
> > The first patch is preparation with no functional changes, makes
> > do_mkdirat accept struct filename pointer rather than the user string.
> > 
> > The second one leverages that to implement mkdirat in io_uring.
> 
> Looks good to me - you should send the first patch to linux-fsdevel (and
> CC Al Viro), really needs to be acked on that side before it can go in.

I'll resend the whole series with Al Viro and linux-fsdevel CCed, hope
that is OK, gives them a bit more context and they can ignore the
io_uring part. Hope that is OK.

> Also, have you written some test cases?

Yes, as part of liburing change - I'll send that shortly.

-- 
Dmitry Kadashev

[PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

This adds mkdirat support to io_uring and is heavily based on recently
added renameat() / unlinkat() support.

The first patch is preparation with no functional changes, makes
do_mkdirat accept struct filename pointer rather than the user string.

The second one leverages that to implement mkdirat in io_uring.

Based on for-5.11/io_uring.

Dmitry Kadashev (2):
  fs: make do_mkdirat() take struct filename
  io_uring: add support for IORING_OP_MKDIRAT

 fs/internal.h                 |  1 +
 fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
 fs/namei.c                    | 20 ++++++++----
 include/uapi/linux/io_uring.h |  1 +
 4 files changed, 74 insertions(+), 6 deletions(-)

-- 
2.28.0

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Mon, Nov 16, 2020 at 11:45:27AM +0700, Dmitry Kadashev wrote:
> This adds mkdirat support to io_uring and is heavily based on recently
> added renameat() / unlinkat() support.
> 
> The first patch is preparation with no functional changes, makes
> do_mkdirat accept struct filename pointer rather than the user string.
> 
> The second one leverages that to implement mkdirat in io_uring.
> 
> Based on for-5.11/io_uring.
> 
> Dmitry Kadashev (2):
>   fs: make do_mkdirat() take struct filename
>   io_uring: add support for IORING_OP_MKDIRAT
> 
>  fs/internal.h                 |  1 +
>  fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
>  fs/namei.c                    | 20 ++++++++----
>  include/uapi/linux/io_uring.h |  1 +
>  4 files changed, 74 insertions(+), 6 deletions(-)
> 
> -- 
> 2.28.0
> 

Hi Al Viro,

Ping. Jens mentioned before that this looks fine by him, but you or
someone from fsdevel should approve the namei.c part first.

Thanks,
Dmitry

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Fri, Dec 4, 2020 at 5:57 PM Dmitry Kadashev <dkadashev@gmail.com> wrote:
>
> On Mon, Nov 16, 2020 at 11:45:27AM +0700, Dmitry Kadashev wrote:
> > This adds mkdirat support to io_uring and is heavily based on recently
> > added renameat() / unlinkat() support.
> >
> > The first patch is preparation with no functional changes, makes
> > do_mkdirat accept struct filename pointer rather than the user string.
> >
> > The second one leverages that to implement mkdirat in io_uring.
> >
> > Based on for-5.11/io_uring.
> >
> > Dmitry Kadashev (2):
> >   fs: make do_mkdirat() take struct filename
> >   io_uring: add support for IORING_OP_MKDIRAT
> >
> >  fs/internal.h                 |  1 +
> >  fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
> >  fs/namei.c                    | 20 ++++++++----
> >  include/uapi/linux/io_uring.h |  1 +
> >  4 files changed, 74 insertions(+), 6 deletions(-)
> >
> > --
> > 2.28.0
> >
>
> Hi Al Viro,
>
> Ping. Jens mentioned before that this looks fine by him, but you or
> someone from fsdevel should approve the namei.c part first.

Another ping.

Jens, you've mentioned the patch looks good to you, and with quite similar
changes (unlinkat, renameat) being sent for 5.11 is there anything that I can do
to help this to be accepted (not necessarily for 5.11 at this point)?

Re: [PATCH 0/2] io_uring: add mkdirat support

[Jens Axboe]

On 12/15/20 4:43 AM, Dmitry Kadashev wrote:
> On Fri, Dec 4, 2020 at 5:57 PM Dmitry Kadashev <dkadashev@gmail.com> wrote:
>>
>> On Mon, Nov 16, 2020 at 11:45:27AM +0700, Dmitry Kadashev wrote:
>>> This adds mkdirat support to io_uring and is heavily based on recently
>>> added renameat() / unlinkat() support.
>>>
>>> The first patch is preparation with no functional changes, makes
>>> do_mkdirat accept struct filename pointer rather than the user string.
>>>
>>> The second one leverages that to implement mkdirat in io_uring.
>>>
>>> Based on for-5.11/io_uring.
>>>
>>> Dmitry Kadashev (2):
>>>   fs: make do_mkdirat() take struct filename
>>>   io_uring: add support for IORING_OP_MKDIRAT
>>>
>>>  fs/internal.h                 |  1 +
>>>  fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
>>>  fs/namei.c                    | 20 ++++++++----
>>>  include/uapi/linux/io_uring.h |  1 +
>>>  4 files changed, 74 insertions(+), 6 deletions(-)
>>>
>>> --
>>> 2.28.0
>>>
>>
>> Hi Al Viro,
>>
>> Ping. Jens mentioned before that this looks fine by him, but you or
>> someone from fsdevel should approve the namei.c part first.
> 
> Another ping.
> 
> Jens, you've mentioned the patch looks good to you, and with quite
> similar changes (unlinkat, renameat) being sent for 5.11 is there
> anything that I can do to help this to be accepted (not necessarily
> for 5.11 at this point)?

Since we're aiming for 5.12 at this point, let's just hold off a bit and
see if Al gets time to ack/review the VFS side of things. There's no
immediate rush.

It's on my TODO list, so we'll get there eventually.

-- 
Jens Axboe

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Tue, Dec 15, 2020 at 11:20 PM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 12/15/20 4:43 AM, Dmitry Kadashev wrote:
> > On Fri, Dec 4, 2020 at 5:57 PM Dmitry Kadashev <dkadashev@gmail.com> wrote:
> >>
> >> On Mon, Nov 16, 2020 at 11:45:27AM +0700, Dmitry Kadashev wrote:
> >>> This adds mkdirat support to io_uring and is heavily based on recently
> >>> added renameat() / unlinkat() support.
> >>>
> >>> The first patch is preparation with no functional changes, makes
> >>> do_mkdirat accept struct filename pointer rather than the user string.
> >>>
> >>> The second one leverages that to implement mkdirat in io_uring.
> >>>
> >>> Based on for-5.11/io_uring.
> >>>
> >>> Dmitry Kadashev (2):
> >>>   fs: make do_mkdirat() take struct filename
> >>>   io_uring: add support for IORING_OP_MKDIRAT
> >>>
> >>>  fs/internal.h                 |  1 +
> >>>  fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
> >>>  fs/namei.c                    | 20 ++++++++----
> >>>  include/uapi/linux/io_uring.h |  1 +
> >>>  4 files changed, 74 insertions(+), 6 deletions(-)
> >>>
> >>> --
> >>> 2.28.0
> >>>
> >>
> >> Hi Al Viro,
> >>
> >> Ping. Jens mentioned before that this looks fine by him, but you or
> >> someone from fsdevel should approve the namei.c part first.
> >
> > Another ping.
> >
> > Jens, you've mentioned the patch looks good to you, and with quite
> > similar changes (unlinkat, renameat) being sent for 5.11 is there
> > anything that I can do to help this to be accepted (not necessarily
> > for 5.11 at this point)?
>
> Since we're aiming for 5.12 at this point, let's just hold off a bit and
> see if Al gets time to ack/review the VFS side of things. There's no
> immediate rush.

OK, sounds good, thanks.

-- 
Dmitry Kadashev

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Tue, Dec 15, 2020 at 11:20 PM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 12/15/20 4:43 AM, Dmitry Kadashev wrote:
> > On Fri, Dec 4, 2020 at 5:57 PM Dmitry Kadashev <dkadashev@gmail.com> wrote:
> >>
> >> On Mon, Nov 16, 2020 at 11:45:27AM +0700, Dmitry Kadashev wrote:
> >>> This adds mkdirat support to io_uring and is heavily based on recently
> >>> added renameat() / unlinkat() support.
> >>>
> >>> The first patch is preparation with no functional changes, makes
> >>> do_mkdirat accept struct filename pointer rather than the user string.
> >>>
> >>> The second one leverages that to implement mkdirat in io_uring.
> >>>
> >>> Based on for-5.11/io_uring.
> >>>
> >>> Dmitry Kadashev (2):
> >>>   fs: make do_mkdirat() take struct filename
> >>>   io_uring: add support for IORING_OP_MKDIRAT
> >>>
> >>>  fs/internal.h                 |  1 +
> >>>  fs/io_uring.c                 | 58 +++++++++++++++++++++++++++++++++++
> >>>  fs/namei.c                    | 20 ++++++++----
> >>>  include/uapi/linux/io_uring.h |  1 +
> >>>  4 files changed, 74 insertions(+), 6 deletions(-)
> >>>
> >>> --
> >>> 2.28.0
> >>>
> >>
> >> Hi Al Viro,
> >>
> >> Ping. Jens mentioned before that this looks fine by him, but you or
> >> someone from fsdevel should approve the namei.c part first.
> >
> > Another ping.
> >
> > Jens, you've mentioned the patch looks good to you, and with quite
> > similar changes (unlinkat, renameat) being sent for 5.11 is there
> > anything that I can do to help this to be accepted (not necessarily
> > for 5.11 at this point)?
>
> Since we're aiming for 5.12 at this point, let's just hold off a bit and
> see if Al gets time to ack/review the VFS side of things. There's no
> immediate rush.
>
> It's on my TODO list, so we'll get there eventually.

Another reminder, since afaict 5.12 stuff is being merged now.

-- 
Dmitry Kadashev

Re: [PATCH 0/2] io_uring: add mkdirat support

[Jens Axboe]

On 11/15/20 9:45 PM, Dmitry Kadashev wrote:
> This adds mkdirat support to io_uring and is heavily based on recently
> added renameat() / unlinkat() support.
> 
> The first patch is preparation with no functional changes, makes
> do_mkdirat accept struct filename pointer rather than the user string.
> 
> The second one leverages that to implement mkdirat in io_uring.
> 
> Based on for-5.11/io_uring.

I want to tentatively queue this up. Do you have the liburing support
and test case(s) for it as well that you can send?

-- 
Jens Axboe

Re: [PATCH 0/2] io_uring: add mkdirat support

[Dmitry Kadashev]

On Wed, Jan 27, 2021 at 5:35 AM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 11/15/20 9:45 PM, Dmitry Kadashev wrote:
> > This adds mkdirat support to io_uring and is heavily based on recently
> > added renameat() / unlinkat() support.
> >
> > The first patch is preparation with no functional changes, makes
> > do_mkdirat accept struct filename pointer rather than the user string.
> >
> > The second one leverages that to implement mkdirat in io_uring.
> >
> > Based on for-5.11/io_uring.
>
> I want to tentatively queue this up. Do you have the liburing support
> and test case(s) for it as well that you can send?

I do, I've sent it in the past, here it is:
https://lore.kernel.org/io-uring/20201116051005.1100302-1-dkadashev@gmail.com/

I need to (figure out the way to) fix the kernel / namei side after Al's
comments though.

-- 
Dmitry Kadashev

Re: [PATCH 0/2] io_uring: add mkdirat support

[Jens Axboe]

On 1/27/21 4:06 AM, Dmitry Kadashev wrote:
> On Wed, Jan 27, 2021 at 5:35 AM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 11/15/20 9:45 PM, Dmitry Kadashev wrote:
>>> This adds mkdirat support to io_uring and is heavily based on recently
>>> added renameat() / unlinkat() support.
>>>
>>> The first patch is preparation with no functional changes, makes
>>> do_mkdirat accept struct filename pointer rather than the user string.
>>>
>>> The second one leverages that to implement mkdirat in io_uring.
>>>
>>> Based on for-5.11/io_uring.
>>
>> I want to tentatively queue this up. Do you have the liburing support
>> and test case(s) for it as well that you can send?
> 
> I do, I've sent it in the past, here it is:
> https://lore.kernel.org/io-uring/20201116051005.1100302-1-dkadashev@gmail.com/

I thought so, thanks. I'll queue it up once we have agreement on the
kernel side.

> I need to (figure out the way to) fix the kernel / namei side after Al's
> comments though.

Thanks, yes please do and re-post it.

-- 
Jens Axboe