[PATCH v1 5/5] io_uring: add fgetxattr and getxattr support

Stefan Roesch
2021-11-29T22:13:11Z

Summary:

This adds support to io_uring for the following API's:
- fgetxattr
- getxattr

Signed-off-by: Stefan Roesch <shr@fb.com>
---
fs/io_uring.c | 152 ++++++++++++++++++++++++++++++++++
include/uapi/linux/io_uring.h | 2 +
2 files changed, 154 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4a18431e13a3..265024204a59 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1114,6 +1114,10 @@ static const struct io_op_def io_op_defs[] = {
[IORING_OP_MKDIRAT] = {},
[IORING_OP_SYMLINKAT] = {},
[IORING_OP_LINKAT] = {},
+ [IORING_OP_FGETXATTR] = {
+ .needs_file = 1
+ },
+ [IORING_OP_GETXATTR] = {},
[IORING_OP_FSETXATTR] = {
.needs_file = 1
},
@@ -3831,6 +3835,135 @@ static int io_renameat(struct io_kiocb *req, unsigned int issue_flags)
return 0;
}

+static int __io_getxattr_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_xattr *ix = &req->xattr;
+ const char __user *name;
+ int ret;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->ioprio))
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ ix->filename = NULL;
+ ix->value = NULL;
+ name = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ ix->ctx.value = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ ix->ctx.size = READ_ONCE(sqe->len);
+ ix->ctx.flags = READ_ONCE(sqe->xattr_flags);
+
+ if (ix->ctx.flags)
+ return -EINVAL;
+
+ ix->ctx.name = kmalloc(XATTR_NAME_MAX + 1, GFP_KERNEL);
+ if (!ix->ctx.name)
+ return -ENOMEM;
+
+ ret = strncpy_from_user(ix->ctx.name, name, XATTR_NAME_MAX + 1);
+ if (!ret || ret == XATTR_NAME_MAX + 1)
+ ret = -ERANGE;
+ if (ret < 0) {
+ kfree(ix->ctx.name);
+ return ret;
+ }
+
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_fgetxattr_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (!req->file)
+ return -EBADF;
+
+ return __io_getxattr_prep(req, sqe);
+}
+
+static int io_getxattr_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_xattr *ix = &req->xattr;
+ const char __user *path;
+ int ret;
+
+ ret = __io_getxattr_prep(req, sqe);
+ if (ret)
+ return ret;
+
+ path = u64_to_user_ptr(READ_ONCE(sqe->addr3));
+
+ ix->filename = getname_flags(path, LOOKUP_FOLLOW, NULL);
+ if (IS_ERR(ix->filename)) {
+ ret = PTR_ERR(ix->filename);
+ ix->filename = NULL;
+ }
+
+ return ret;
+}
+
+static int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_xattr *ix = &req->xattr;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_getxattr(mnt_user_ns(req->file->f_path.mnt),
+ req->file->f_path.dentry,
+ ix->ctx.name,
+ (void __user *)ix->ctx.value,
+ ix->ctx.size);
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ kfree(ix->ctx.name);
+ if (ret < 0)
+ req_set_fail(req);
+
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_getxattr(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_xattr *ix = &req->xattr;
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+ struct path path;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+retry:
+ ret = user_path_at_empty(AT_FDCWD, ix->filename, lookup_flags, &path);
+ if (!ret) {
+ ret = do_getxattr(mnt_user_ns(path.mnt),
+ path.dentry,
+ ix->ctx.name,
+ (void __user *)ix->ctx.value,
+ ix->ctx.size);
+
+ path_put(&path);
+ if (retry_estale(ret, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
+ }
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ kfree(ix->ctx.name);
+ if (ret < 0)
+ req_set_fail(req);
+
+ io_req_complete(req, ret);
+ return 0;
+}
+
static int __io_setxattr_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe,
struct user_namespace *user_ns)
@@ -6684,6 +6817,10 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return io_symlinkat_prep(req, sqe);
case IORING_OP_LINKAT:
return io_linkat_prep(req, sqe);
+ case IORING_OP_FGETXATTR:
+ return io_fgetxattr_prep(req, sqe);
+ case IORING_OP_GETXATTR:
+ return io_getxattr_prep(req, sqe);
case IORING_OP_FSETXATTR:
return io_fsetxattr_prep(req, sqe);
case IORING_OP_SETXATTR:
@@ -6831,6 +6968,15 @@ static void io_clean_op(struct io_kiocb *req)
putname(req->hardlink.oldpath);
putname(req->hardlink.newpath);
break;
+
+ case IORING_OP_GETXATTR:
+ if (req->xattr.filename)
+ putname(req->xattr.filename);
+ fallthrough;
+ case IORING_OP_FGETXATTR:
+ kfree(req->xattr.ctx.name);
+ break;
+
case IORING_OP_SETXATTR:
if (req->xattr.filename)
putname(req->xattr.filename);
@@ -6982,6 +7128,12 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
case IORING_OP_LINKAT:
ret = io_linkat(req, issue_flags);
break;
+ case IORING_OP_FGETXATTR:
+ ret = io_fgetxattr(req, issue_flags);
+ break;
+ case IORING_OP_GETXATTR:
+ ret = io_getxattr(req, issue_flags);
+ break;
case IORING_OP_FSETXATTR:
ret = io_fsetxattr(req, issue_flags);
break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index dbf473900da2..cd9160272308 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -145,7 +145,9 @@ enum {
IORING_OP_MKDIRAT,
IORING_OP_SYMLINKAT,
IORING_OP_LINKAT,
+ IORING_OP_FGETXATTR,
IORING_OP_FSETXATTR,
+ IORING_OP_GETXATTR,
IORING_OP_SETXATTR,

/* this goes last, obviously */
--
2.30.2