io_uring: add support for IORING_OP_UNLINKAT

IORING_OP_UNLINKAT behaves like unlinkat(2) and takes the same flags
and arguments.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 94a5e16..c8ecbc0 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -555,6 +555,13 @@ struct io_rename {
        int                             flags;
 };
 
+struct io_unlink {
+       struct file                     *file;
+       int                             dfd;
+       int                             flags;
+       struct filename                 *filename;
+};
+
 struct io_completion {
        struct file                     *file;
        struct list_head                list;
@@ -683,6 +690,7 @@ struct io_kiocb {
                struct io_statx         statx;
                struct io_shutdown      shutdown;
                struct io_rename        rename;
+               struct io_unlink        unlink;
                /* use only after cleaning per-op data, see io_clean_op() */
                struct io_completion    compl;
        };
@@ -957,6 +965,10 @@ static const struct io_op_def io_op_defs[] = {
                .work_flags             = IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
                                                IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
        },
+       [IORING_OP_UNLINKAT] = {
+               .work_flags             = IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
+                                               IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
+       },
 };
 
 enum io_mem_account {
@@ -3706,6 +3718,50 @@ static int io_renameat(struct io_kiocb *req, bool force_nonblock)
        return 0;
 }
 
+static int io_unlinkat_prep(struct io_kiocb *req,
+                           const struct io_uring_sqe *sqe)
+{
+       struct io_unlink *un = &req->unlink;
+       const char __user *fname;
+
+       if (unlikely(req->flags & REQ_F_FIXED_FILE))
+               return -EBADF;
+
+       un->dfd = READ_ONCE(sqe->fd);
+
+       un->flags = READ_ONCE(sqe->unlink_flags);
+       if (un->flags & ~AT_REMOVEDIR)
+               return -EINVAL;
+
+       fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       un->filename = getname(fname);
+       if (IS_ERR(un->filename))
+               return PTR_ERR(un->filename);
+
+       req->flags |= REQ_F_NEED_CLEANUP;
+       return 0;
+}
+
+static int io_unlinkat(struct io_kiocb *req, bool force_nonblock)
+{
+       struct io_unlink *un = &req->unlink;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       if (un->flags & AT_REMOVEDIR)
+               ret = do_rmdir(un->dfd, un->filename);
+       else
+               ret = do_unlinkat(un->dfd, un->filename);
+
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_req_complete(req, ret);
+       return 0;
+}
+
 static int io_shutdown_prep(struct io_kiocb *req,
                            const struct io_uring_sqe *sqe)
 {
@@ -5932,6 +5988,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
                return io_shutdown_prep(req, sqe);
        case IORING_OP_RENAMEAT:
                return io_renameat_prep(req, sqe);
+       case IORING_OP_UNLINKAT:
+               return io_unlinkat_prep(req, sqe);
        }
 
        printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -6073,6 +6131,9 @@ static void __io_clean_op(struct io_kiocb *req)
                        putname(req->rename.oldpath);
                        putname(req->rename.newpath);
                        break;
+               case IORING_OP_UNLINKAT:
+                       putname(req->unlink.filename);
+                       break;
                }
                req->flags &= ~REQ_F_NEED_CLEANUP;
        }
@@ -6185,6 +6246,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
        case IORING_OP_RENAMEAT:
                ret = io_renameat(req, force_nonblock);
                break;
+       case IORING_OP_UNLINKAT:
+               ret = io_unlinkat(req, force_nonblock);
+               break;
        default:
                ret = -EINVAL;
                break;

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index c9a58bc..557e7ea 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -43,6 +43,7 @@ struct io_uring_sqe {
                __u32           fadvise_advice;
                __u32           splice_flags;
                __u32           rename_flags;
+               __u32           unlink_flags;
        };
        __u64   user_data;      /* data to be passed back at completion time */
        union {
@@ -135,6 +136,7 @@ enum {
        IORING_OP_TEE,
        IORING_OP_SHUTDOWN,
        IORING_OP_RENAMEAT,
+       IORING_OP_UNLINKAT,
 
        /* this goes last, obviously */
        IORING_OP_LAST,