Commit 66d7ac6b authored by Al Viro's avatar Al Viro
Browse files

replace do_setxattr() with saner helpers. 



io_uring setxattr logics duplicates stuff from fs/xattr.c; provide
saner helpers (filename_setxattr() and file_setxattr() resp.) and
use them.

NB: putname(ERR_PTR()) is a no-op

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a10c4c5e

fs/internal.h

+3 −3
Original line number Diff line number Diff line
@@ -285,10 +285,10 @@ ssize_t do_getxattr(struct mnt_idmap *idmap, 
		    struct dentry *d,

		    struct kernel_xattr_ctx *ctx);



int file_setxattr(struct file *file, struct kernel_xattr_ctx *ctx);

int filename_setxattr(int dfd, struct filename *filename,

		      unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);

int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx);

int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,

		struct kernel_xattr_ctx *ctx);



int import_xattr_name(struct xattr_name *kname, const char __user *name);



int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);

fs/xattr.c

+44 −25
Original line number Diff line number Diff line
@@ -626,7 +626,7 @@ int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx) 
	return error;

}



int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,

static int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,

		struct kernel_xattr_ctx *ctx)

{

	if (is_posix_acl_xattr(ctx->kname->name))
@@ -637,32 +637,32 @@ int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, 
			ctx->kvalue, ctx->size, ctx->flags);

}



static int path_setxattr(const char __user *pathname,

			 const char __user *name, const void __user *value,

			 size_t size, int flags, unsigned int lookup_flags)

int file_setxattr(struct file *f, struct kernel_xattr_ctx *ctx)

{

	struct xattr_name kname;

	struct kernel_xattr_ctx ctx = {

		.cvalue   = value,

		.kvalue   = NULL,

		.size     = size,

		.kname    = &kname,

		.flags    = flags,

	};

	struct path path;

	int error;

	int error = mnt_want_write_file(f);



	error = setxattr_copy(name, &ctx);

	if (error)

	if (!error) {

		audit_file(f);

		error = do_setxattr(file_mnt_idmap(f), f->f_path.dentry, ctx);

		mnt_drop_write_file(f);

	}

	return error;

}



/* unconditionally consumes filename */

int filename_setxattr(int dfd, struct filename *filename,

		      unsigned int lookup_flags, struct kernel_xattr_ctx *ctx)

{

	struct path path;

	int error;



retry:

	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);

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

	if (error)

		goto out;

	error = mnt_want_write(path.mnt);

	if (!error) {

		error = do_setxattr(mnt_idmap(path.mnt), path.dentry, &ctx);

		error = do_setxattr(mnt_idmap(path.mnt), path.dentry, ctx);

		mnt_drop_write(path.mnt);

	}

	path_put(&path);
@@ -672,6 +672,30 @@ static int path_setxattr(const char __user *pathname, 
	}



out:

	putname(filename);

	return error;

}



static int path_setxattr(const char __user *pathname,

			 const char __user *name, const void __user *value,

			 size_t size, int flags, unsigned int lookup_flags)

{

	struct xattr_name kname;

	struct kernel_xattr_ctx ctx = {

		.cvalue   = value,

		.kvalue   = NULL,

		.size     = size,

		.kname    = &kname,

		.flags    = flags,

	};

	int error;



	error = setxattr_copy(name, &ctx);

	if (error)

		return error;



	error = filename_setxattr(AT_FDCWD, getname(pathname), lookup_flags,

				  &ctx);

	kvfree(ctx.kvalue);

	return error;

}
@@ -707,17 +731,12 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, 


	if (fd_empty(f))

		return -EBADF;

	audit_file(fd_file(f));



	error = setxattr_copy(name, &ctx);

	if (error)

		return error;



	error = mnt_want_write_file(fd_file(f));

	if (!error) {

		error = do_setxattr(file_mnt_idmap(fd_file(f)),

				    fd_file(f)->f_path.dentry, &ctx);

		mnt_drop_write_file(fd_file(f));

	}

	error = file_setxattr(fd_file(f), &ctx);

	kvfree(ctx.kvalue);

	return error;

}

io_uring/xattr.c

+7 −34
Original line number Diff line number Diff line
@@ -187,12 +187,10 @@ int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	path = u64_to_user_ptr(READ_ONCE(sqe->addr3));



	ix->filename = getname(path);

	if (IS_ERR(ix->filename)) {

		ret = PTR_ERR(ix->filename);

		ix->filename = NULL;

	}

	if (IS_ERR(ix->filename))

		return PTR_ERR(ix->filename);



	return ret;

	return 0;

}



int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
@@ -200,28 +198,14 @@ int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	return __io_setxattr_prep(req, sqe);

}



static int __io_setxattr(struct io_kiocb *req, unsigned int issue_flags,

			const struct path *path)

{

	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);

	int ret;



	ret = mnt_want_write(path->mnt);

	if (!ret) {

		ret = do_setxattr(mnt_idmap(path->mnt), path->dentry, &ix->ctx);

		mnt_drop_write(path->mnt);

	}



	return ret;

}



int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);

	int ret;



	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = __io_setxattr(req, issue_flags, &req->file->f_path);

	ret = file_setxattr(req->file, &ix->ctx);

	io_xattr_finish(req, ret);

	return IOU_OK;

}
@@ -229,23 +213,12 @@ int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags) 
int io_setxattr(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);

	unsigned int lookup_flags = LOOKUP_FOLLOW;

	struct path path;

	int ret;



	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



retry:

	ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);

	if (!ret) {

		ret = __io_setxattr(req, issue_flags, &path);

		path_put(&path);

		if (retry_estale(ret, lookup_flags)) {

			lookup_flags |= LOOKUP_REVAL;

			goto retry;

		}

	}



	ret = filename_setxattr(AT_FDCWD, ix->filename, LOOKUP_FOLLOW, &ix->ctx);

	ix->filename = NULL;

	io_xattr_finish(req, ret);

	return IOU_OK;

}