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brintos / linux-shallow public Read only

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1// SPDX-License-Identifier: GPL-2.02#include <linux/kernel.h>3#include <linux/errno.h>4#include <linux/fs.h>5#include <linux/file.h>6#include <linux/mm.h>7#include <linux/slab.h>8#include <linux/namei.h>9#include <linux/io_uring.h>10#include <linux/xattr.h>11 12#include <uapi/linux/io_uring.h>13 14#include "../fs/internal.h"15 16#include "io_uring.h"17#include "xattr.h"18 19struct io_xattr {20	struct file			*file;21	struct xattr_ctx		ctx;22	struct filename			*filename;23};24 25void io_xattr_cleanup(struct io_kiocb *req)26{27	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);28 29	if (ix->filename)30		putname(ix->filename);31 32	kfree(ix->ctx.kname);33	kvfree(ix->ctx.kvalue);34}35 36static void io_xattr_finish(struct io_kiocb *req, int ret)37{38	req->flags &= ~REQ_F_NEED_CLEANUP;39 40	io_xattr_cleanup(req);41	io_req_set_res(req, ret, 0);42}43 44static int __io_getxattr_prep(struct io_kiocb *req,45			      const struct io_uring_sqe *sqe)46{47	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);48	const char __user *name;49	int ret;50 51	if (unlikely(req->flags & REQ_F_FIXED_FILE))52		return -EBADF;53 54	ix->filename = NULL;55	ix->ctx.kvalue = NULL;56	name = u64_to_user_ptr(READ_ONCE(sqe->addr));57	ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));58	ix->ctx.size = READ_ONCE(sqe->len);59	ix->ctx.flags = READ_ONCE(sqe->xattr_flags);60 61	if (ix->ctx.flags)62		return -EINVAL;63 64	ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL);65	if (!ix->ctx.kname)66		return -ENOMEM;67 68	ret = strncpy_from_user(ix->ctx.kname->name, name,69				sizeof(ix->ctx.kname->name));70	if (!ret || ret == sizeof(ix->ctx.kname->name))71		ret = -ERANGE;72	if (ret < 0) {73		kfree(ix->ctx.kname);74		return ret;75	}76 77	req->flags |= REQ_F_NEED_CLEANUP;78	req->flags |= REQ_F_FORCE_ASYNC;79	return 0;80}81 82int io_fgetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)83{84	return __io_getxattr_prep(req, sqe);85}86 87int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)88{89	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);90	const char __user *path;91	int ret;92 93	ret = __io_getxattr_prep(req, sqe);94	if (ret)95		return ret;96 97	path = u64_to_user_ptr(READ_ONCE(sqe->addr3));98 99	ix->filename = getname_flags(path, LOOKUP_FOLLOW);100	if (IS_ERR(ix->filename)) {101		ret = PTR_ERR(ix->filename);102		ix->filename = NULL;103	}104 105	return ret;106}107 108int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags)109{110	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);111	int ret;112 113	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);114 115	ret = do_getxattr(file_mnt_idmap(req->file),116			req->file->f_path.dentry,117			&ix->ctx);118 119	io_xattr_finish(req, ret);120	return IOU_OK;121}122 123int io_getxattr(struct io_kiocb *req, unsigned int issue_flags)124{125	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);126	unsigned int lookup_flags = LOOKUP_FOLLOW;127	struct path path;128	int ret;129 130	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);131 132retry:133	ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);134	if (!ret) {135		ret = do_getxattr(mnt_idmap(path.mnt), path.dentry, &ix->ctx);136 137		path_put(&path);138		if (retry_estale(ret, lookup_flags)) {139			lookup_flags |= LOOKUP_REVAL;140			goto retry;141		}142	}143 144	io_xattr_finish(req, ret);145	return IOU_OK;146}147 148static int __io_setxattr_prep(struct io_kiocb *req,149			const struct io_uring_sqe *sqe)150{151	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);152	const char __user *name;153	int ret;154 155	if (unlikely(req->flags & REQ_F_FIXED_FILE))156		return -EBADF;157 158	ix->filename = NULL;159	name = u64_to_user_ptr(READ_ONCE(sqe->addr));160	ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));161	ix->ctx.kvalue = NULL;162	ix->ctx.size = READ_ONCE(sqe->len);163	ix->ctx.flags = READ_ONCE(sqe->xattr_flags);164 165	ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL);166	if (!ix->ctx.kname)167		return -ENOMEM;168 169	ret = setxattr_copy(name, &ix->ctx);170	if (ret) {171		kfree(ix->ctx.kname);172		return ret;173	}174 175	req->flags |= REQ_F_NEED_CLEANUP;176	req->flags |= REQ_F_FORCE_ASYNC;177	return 0;178}179 180int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)181{182	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);183	const char __user *path;184	int ret;185 186	ret = __io_setxattr_prep(req, sqe);187	if (ret)188		return ret;189 190	path = u64_to_user_ptr(READ_ONCE(sqe->addr3));191 192	ix->filename = getname_flags(path, LOOKUP_FOLLOW);193	if (IS_ERR(ix->filename)) {194		ret = PTR_ERR(ix->filename);195		ix->filename = NULL;196	}197 198	return ret;199}200 201int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)202{203	return __io_setxattr_prep(req, sqe);204}205 206static int __io_setxattr(struct io_kiocb *req, unsigned int issue_flags,207			const struct path *path)208{209	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);210	int ret;211 212	ret = mnt_want_write(path->mnt);213	if (!ret) {214		ret = do_setxattr(mnt_idmap(path->mnt), path->dentry, &ix->ctx);215		mnt_drop_write(path->mnt);216	}217 218	return ret;219}220 221int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)222{223	int ret;224 225	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);226 227	ret = __io_setxattr(req, issue_flags, &req->file->f_path);228	io_xattr_finish(req, ret);229	return IOU_OK;230}231 232int io_setxattr(struct io_kiocb *req, unsigned int issue_flags)233{234	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);235	unsigned int lookup_flags = LOOKUP_FOLLOW;236	struct path path;237	int ret;238 239	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);240 241retry:242	ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);243	if (!ret) {244		ret = __io_setxattr(req, issue_flags, &path);245		path_put(&path);246		if (retry_estale(ret, lookup_flags)) {247			lookup_flags |= LOOKUP_REVAL;248			goto retry;249		}250	}251 252	io_xattr_finish(req, ret);253	return IOU_OK;254}255