Commit b080cee7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-5.18/io_uring-statx-2022-03-18' of git://git.kernel.dk/linux-block 

Pull io_uring statx fixes from Jens Axboe:
 "On top of the main io_uring branch, this is to ensure that the
  filename component of statx is stable after submit.

  That requires a few VFS related changes"

* tag 'for-5.18/io_uring-statx-2022-03-18' of git://git.kernel.dk/linux-block:
  io-uring: Make statx API stable
parents af472a9e 1b6fe6e0

fs/internal.h

+3 −1
Original line number Diff line number Diff line
@@ -184,7 +184,9 @@ int sb_init_dio_done_wq(struct super_block *sb); 
/*

 * fs/stat.c:

 */

int do_statx(int dfd, const char __user *filename, unsigned flags,



int getname_statx_lookup_flags(int flags);

int do_statx(int dfd, struct filename *filename, unsigned int flags,

	     unsigned int mask, struct statx __user *buffer);



/*

fs/io_uring.c

+20 −2
Original line number Diff line number Diff line
@@ -675,7 +675,7 @@ struct io_statx { 
	int				dfd;

	unsigned int			mask;

	unsigned int			flags;

	const char __user		*filename;

	struct filename			*filename;

	struct statx __user		*buffer;

};
@@ -5000,6 +5000,8 @@ static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags) 


static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

	const char __user *path;



	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;

	if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
@@ -5009,10 +5011,22 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 


	req->statx.dfd = READ_ONCE(sqe->fd);

	req->statx.mask = READ_ONCE(sqe->len);

	req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));

	path = u64_to_user_ptr(READ_ONCE(sqe->addr));

	req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));

	req->statx.flags = READ_ONCE(sqe->statx_flags);



	req->statx.filename = getname_flags(path,

					getname_statx_lookup_flags(req->statx.flags),

					NULL);



	if (IS_ERR(req->statx.filename)) {

		int ret = PTR_ERR(req->statx.filename);



		req->statx.filename = NULL;

		return ret;

	}



	req->flags |= REQ_F_NEED_CLEANUP;

	return 0;

}
@@ -7112,6 +7126,10 @@ static void io_clean_op(struct io_kiocb *req) 
			putname(req->hardlink.oldpath);

			putname(req->hardlink.newpath);

			break;

		case IORING_OP_STATX:

			if (req->statx.filename)

				putname(req->statx.filename);

			break;

		}

	}

	if ((req->flags & REQ_F_POLLED) && req->apoll) {

fs/stat.c

+35 −14
Original line number Diff line number Diff line
@@ -184,6 +184,20 @@ int vfs_fstat(int fd, struct kstat *stat) 
	return error;

}



int getname_statx_lookup_flags(int flags)

{

	int lookup_flags = 0;



	if (!(flags & AT_SYMLINK_NOFOLLOW))

		lookup_flags |= LOOKUP_FOLLOW;

	if (!(flags & AT_NO_AUTOMOUNT))

		lookup_flags |= LOOKUP_AUTOMOUNT;

	if (flags & AT_EMPTY_PATH)

		lookup_flags |= LOOKUP_EMPTY;



	return lookup_flags;

}



/**

 * vfs_statx - Get basic and extra attributes by filename

 * @dfd: A file descriptor representing the base dir for a relative filename
@@ -199,26 +213,19 @@ int vfs_fstat(int fd, struct kstat *stat) 
 *

 * 0 will be returned on success, and a -ve error code if unsuccessful.

 */

static int vfs_statx(int dfd, const char __user *filename, int flags,

static int vfs_statx(int dfd, struct filename *filename, int flags,

	      struct kstat *stat, u32 request_mask)

{

	struct path path;

	unsigned lookup_flags = 0;

	unsigned int lookup_flags = getname_statx_lookup_flags(flags);

	int error;



	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |

		      AT_STATX_SYNC_TYPE))

		return -EINVAL;



	if (!(flags & AT_SYMLINK_NOFOLLOW))

		lookup_flags |= LOOKUP_FOLLOW;

	if (!(flags & AT_NO_AUTOMOUNT))

		lookup_flags |= LOOKUP_AUTOMOUNT;

	if (flags & AT_EMPTY_PATH)

		lookup_flags |= LOOKUP_EMPTY;



retry:

	error = user_path_at(dfd, filename, lookup_flags, &path);

	error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);

	if (error)

		goto out;
@@ -240,8 +247,15 @@ static int vfs_statx(int dfd, const char __user *filename, int flags, 
int vfs_fstatat(int dfd, const char __user *filename,

			      struct kstat *stat, int flags)

{

	return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,

			 stat, STATX_BASIC_STATS);

	int ret;

	int statx_flags = flags | AT_NO_AUTOMOUNT;

	struct filename *name;



	name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);

	ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);

	putname(name);



	return ret;

}



#ifdef __ARCH_WANT_OLD_STAT
@@ -602,7 +616,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer) 
	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;

}



int do_statx(int dfd, const char __user *filename, unsigned flags,

int do_statx(int dfd, struct filename *filename, unsigned int flags,

	     unsigned int mask, struct statx __user *buffer)

{

	struct kstat stat;
@@ -636,7 +650,14 @@ SYSCALL_DEFINE5(statx, 
		unsigned int, mask,

		struct statx __user *, buffer)

{

	return do_statx(dfd, filename, flags, mask, buffer);

	int ret;

	struct filename *name;



	name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);

	ret = do_statx(dfd, name, flags, mask, buffer);

	putname(name);



	return ret;

}



#ifdef CONFIG_COMPAT