io_uring: add fsetxattr and setxattr support

This adds support to io_uring for the fsetxattr and setxattr API.

Signed-off-by: Stefan Roesch <shr@fb.com>
Link: https://lore.kernel.org/r/20211223235123.4092764-5-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c769557866da470f57e14a4b10bf433ea5897655..cde0013e59ed6bda6bda7876c1981249293912f8 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -81,6 +81,7 @@
 #include <linux/tracehook.h>
 #include <linux/audit.h>
 #include <linux/security.h>
+#include <linux/xattr.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/io_uring.h>
@@ -725,6 +726,13 @@ struct io_async_rw {
        struct wait_page_queue          wpq;
 };
 
+struct io_xattr {
+       struct file                     *file;
+       struct xattr_ctx                ctx;
+       void                            *value;
+       struct filename                 *filename;
+};
+
 enum {
        REQ_F_FIXED_FILE_BIT    = IOSQE_FIXED_FILE_BIT,
        REQ_F_IO_DRAIN_BIT      = IOSQE_IO_DRAIN_BIT,
@@ -865,6 +873,7 @@ struct io_kiocb {
                struct io_symlink       symlink;
                struct io_hardlink      hardlink;
                struct io_getdents      getdents;
+               struct io_xattr         xattr;
        };
 
        u8                              opcode;
@@ -1117,6 +1126,10 @@ static const struct io_op_def io_op_defs[] = {
        [IORING_OP_GETDENTS] = {
                .needs_file             = 1,
        },
+       [IORING_OP_FSETXATTR] = {
+               .needs_file = 1
+       },
+       [IORING_OP_SETXATTR] = {},
 };
 
 /* requests with any of those set should undergo io_disarm_next() */
@@ -3856,6 +3869,140 @@ static int io_renameat(struct io_kiocb *req, unsigned int issue_flags)
        return 0;
 }
 
+static int __io_setxattr_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;
+       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);
+
+       ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL);
+       if (!ix->ctx.kname)
+               return -ENOMEM;
+
+       ret = setxattr_copy(name, &ix->ctx, &ix->value);
+       if (ret) {
+               kfree(ix->ctx.kname);
+               return ret;
+       }
+
+       req->flags |= REQ_F_NEED_CLEANUP;
+       return 0;
+}
+
+static int io_setxattr_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_setxattr_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_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,
+                       struct path *path)
+{
+       struct io_xattr *ix = &req->xattr;
+       int ret;
+
+       ret = mnt_want_write(path->mnt);
+       if (!ret) {
+               ret = do_setxattr(mnt_user_ns(path->mnt), path->dentry,
+                               &ix->ctx, ix->value);
+               mnt_drop_write(path->mnt);
+       }
+
+       return ret;
+}
+
+static int io_fsetxattr(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 = __io_setxattr(req, issue_flags, &req->file->f_path);
+
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       kfree(ix->ctx.kname);
+
+       if (ix->value)
+               kvfree(ix->value);
+       if (ret < 0)
+               req_set_fail(req);
+
+       io_req_complete(req, ret);
+       return 0;
+}
+
+static int io_setxattr(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 = do_user_path_at_empty(AT_FDCWD, ix->filename, lookup_flags, &path);
+       if (!ret) {
+               ret = __io_setxattr(req, issue_flags, &path);
+               path_put(&path);
+               if (retry_estale(ret, lookup_flags)) {
+                       lookup_flags |= LOOKUP_REVAL;
+                       goto retry;
+               }
+       }
+       putname(ix->filename);
+
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       kfree(ix->ctx.kname);
+
+       if (ix->value)
+               kvfree(ix->value);
+       if (ret < 0)
+               req_set_fail(req);
+
+       io_req_complete(req, ret);
+       return 0;
+}
+
 static int io_unlinkat_prep(struct io_kiocb *req,
                            const struct io_uring_sqe *sqe)
 {
@@ -6588,6 +6735,10 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
                return io_linkat_prep(req, sqe);
        case IORING_OP_GETDENTS:
                return io_getdents_prep(req, sqe);
+       case IORING_OP_FSETXATTR:
+               return io_fsetxattr_prep(req, sqe);
+       case IORING_OP_SETXATTR:
+               return io_setxattr_prep(req, sqe);
        }
 
        printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -6729,6 +6880,14 @@ static void io_clean_op(struct io_kiocb *req)
                        putname(req->hardlink.oldpath);
                        putname(req->hardlink.newpath);
                        break;
+               case IORING_OP_SETXATTR:
+                       if (req->xattr.filename)
+                               putname(req->xattr.filename);
+                       fallthrough;
+               case IORING_OP_FSETXATTR:
+                       kfree(req->xattr.ctx.kname);
+                       kvfree(req->xattr.value);
+                       break;
                }
        }
        if ((req->flags & REQ_F_POLLED) && req->apoll) {
@@ -6874,6 +7033,12 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
        case IORING_OP_GETDENTS:
                ret = io_getdents(req, issue_flags);
                break;
+       case IORING_OP_FSETXATTR:
+               ret = io_fsetxattr(req, issue_flags);
+               break;
+       case IORING_OP_SETXATTR:
+               ret = io_setxattr(req, issue_flags);
+               break;
        default:
                ret = -EINVAL;
                break;
@@ -11254,6 +11419,7 @@ static int __init io_uring_init(void)
        BUILD_BUG_SQE_ELEM(42, __u16,  personality);
        BUILD_BUG_SQE_ELEM(44, __s32,  splice_fd_in);
        BUILD_BUG_SQE_ELEM(44, __u32,  file_index);
+       BUILD_BUG_SQE_ELEM(48, __u64,  addr3);
 
        BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
                     sizeof(struct io_uring_rsrc_update));

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 57dc88db57938760fee2958adfc9296e0a1ccef9..c62a8bec8cd4199b38a8f3cb0367b6e401076b99 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -45,6 +45,7 @@ struct io_uring_sqe {
                __u32           rename_flags;
                __u32           unlink_flags;
                __u32           hardlink_flags;
+               __u32           xattr_flags;
        };
        __u64   user_data;      /* data to be passed back at completion time */
        /* pack this to avoid bogus arm OABI complaints */
@@ -60,7 +61,8 @@ struct io_uring_sqe {
                __s32   splice_fd_in;
                __u32   file_index;
        };
-       __u64   __pad2[2];
+       __u64   addr3;
+       __u64   __pad2[1];
 };
 
 enum {
@@ -144,6 +146,8 @@ enum {
        IORING_OP_SYMLINKAT,
        IORING_OP_LINKAT,
        IORING_OP_GETDENTS,
+       IORING_OP_FSETXATTR,
+       IORING_OP_SETXATTR,
 
        /* this goes last, obviously */
        IORING_OP_LAST,