From patchwork Tue Jul 18 13:21:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Xu X-Patchwork-Id: 13317213 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16B9CEB64DA for ; Tue, 18 Jul 2023 13:22:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232450AbjGRNWO (ORCPT ); Tue, 18 Jul 2023 09:22:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232430AbjGRNVq (ORCPT ); Tue, 18 Jul 2023 09:21:46 -0400 Received: from out-25.mta0.migadu.com (out-25.mta0.migadu.com [IPv6:2001:41d0:1004:224b::19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2C6910B for ; Tue, 18 Jul 2023 06:21:44 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1689686503; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B/R+rnKPRzeQfS6lJcdhdfJcjC3qXMD5PP20ZBMqf6I=; b=AqNPZ/iUY6dsumcUccCAusQCwYBwkPWPGDNTYxXL8/4V8XF4HDe4NYYwTVuZmGVLXkyu7B 6QXiUFxIW41cxJq9YUVjgg3hPdrEiZDPWNmwTnKvyf7fnildKfIrVascPNQwJPLNtr9a3h 79gjBskCW3vcF6PYvCkfvWyioJ/fsQQ= From: Hao Xu To: io-uring@vger.kernel.org, Jens Axboe Cc: Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , linux-fsdevel@vger.kernel.org, Wanpeng Li Subject: [PATCH 3/5] io_uring: add support for getdents Date: Tue, 18 Jul 2023 21:21:10 +0800 Message-Id: <20230718132112.461218-4-hao.xu@linux.dev> In-Reply-To: <20230718132112.461218-1-hao.xu@linux.dev> References: <20230718132112.461218-1-hao.xu@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Hao Xu This add support for getdents64 to io_uring, acting exactly like the syscall: the directory is iterated from it's current's position as stored in the file struct, and the file's position is updated exactly as if getdents64 had been called. For filesystems that support NOWAIT in iterate_shared(), try to use it first; if a user already knows the filesystem they use do not support nowait they can force async through IOSQE_ASYNC in the sqe flags, avoiding the need to bounce back through a useless EAGAIN return. Co-developed-by: Dominique Martinet Signed-off-by: Dominique Martinet Signed-off-by: Hao Xu --- include/uapi/linux/io_uring.h | 7 +++++ io_uring/fs.c | 55 +++++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 ++ io_uring/opdef.c | 8 +++++ 4 files changed, 73 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 36f9c73082de..b200b2600622 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -65,6 +65,7 @@ struct io_uring_sqe { __u32 xattr_flags; __u32 msg_ring_flags; __u32 uring_cmd_flags; + __u32 getdents_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -235,6 +236,7 @@ enum io_uring_op { IORING_OP_URING_CMD, IORING_OP_SEND_ZC, IORING_OP_SENDMSG_ZC, + IORING_OP_GETDENTS, /* this goes last, obviously */ IORING_OP_LAST, @@ -273,6 +275,11 @@ enum io_uring_op { */ #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */ +/* + * sqe->getdents_flags + */ +#define IORING_GETDENTS_REWIND (1U << 0) + /* * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the * command flags for POLL_ADD are stored in sqe->len. diff --git a/io_uring/fs.c b/io_uring/fs.c index f6a69a549fd4..480f25677fed 100644 --- a/io_uring/fs.c +++ b/io_uring/fs.c @@ -47,6 +47,13 @@ struct io_link { int flags; }; +struct io_getdents { + struct file *file; + struct linux_dirent64 __user *dirent; + unsigned int count; + int flags; +}; + int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename); @@ -291,3 +298,51 @@ void io_link_cleanup(struct io_kiocb *req) putname(sl->oldpath); putname(sl->newpath); } + +int io_getdents_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_getdents *gd = io_kiocb_to_cmd(req, struct io_getdents); + + if (READ_ONCE(sqe->off) != 0) + return -EINVAL; + + gd->dirent = u64_to_user_ptr(READ_ONCE(sqe->addr)); + gd->count = READ_ONCE(sqe->len); + + return 0; +} + +int io_getdents(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_getdents *gd = io_kiocb_to_cmd(req, struct io_getdents); + struct file *file = req->file; + unsigned long getdents_flags = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + bool should_lock = file->f_mode & FMODE_ATOMIC_POS; + int ret; + + if (force_nonblock) { + if (!(req->file->f_mode & FMODE_NOWAIT)) + return -EAGAIN; + + getdents_flags = DIR_CONTEXT_F_NOWAIT; + } + + if (should_lock) { + if (!force_nonblock) + mutex_lock(&file->f_pos_lock); + else if (!mutex_trylock(&file->f_pos_lock)) + return -EAGAIN; + } + + ret = vfs_getdents(file, gd->dirent, gd->count, getdents_flags); + if (should_lock) + mutex_unlock(&file->f_pos_lock); + + if (ret == -EAGAIN && force_nonblock) + return -EAGAIN; + + io_req_set_res(req, ret, 0); + return 0; +} + diff --git a/io_uring/fs.h b/io_uring/fs.h index 0bb5efe3d6bb..f83a6f3a678d 100644 --- a/io_uring/fs.h +++ b/io_uring/fs.h @@ -18,3 +18,6 @@ int io_symlinkat(struct io_kiocb *req, unsigned int issue_flags); int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_linkat(struct io_kiocb *req, unsigned int issue_flags); void io_link_cleanup(struct io_kiocb *req); + +int io_getdents_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_getdents(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/opdef.c b/io_uring/opdef.c index 3b9c6489b8b6..1bae6b2a8d0b 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -428,6 +428,11 @@ const struct io_issue_def io_issue_defs[] = { .prep = io_eopnotsupp_prep, #endif }, + [IORING_OP_GETDENTS] = { + .needs_file = 1, + .prep = io_getdents_prep, + .issue = io_getdents, + }, }; @@ -648,6 +653,9 @@ const struct io_cold_def io_cold_defs[] = { .fail = io_sendrecv_fail, #endif }, + [IORING_OP_GETDENTS] = { + .name = "GETDENTS", + }, }; const char *io_uring_get_opcode(u8 opcode)