From patchwork Sat Apr 22 08:40:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 13220926 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 07DE4C6FD18 for ; Sat, 22 Apr 2023 08:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbjDVIk7 (ORCPT ); Sat, 22 Apr 2023 04:40:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229695AbjDVIk4 (ORCPT ); Sat, 22 Apr 2023 04:40:56 -0400 Received: from nautica.notk.org (ipv6.notk.org [IPv6:2001:41d0:1:7a93::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C0FC1BC2; Sat, 22 Apr 2023 01:40:55 -0700 (PDT) Received: by nautica.notk.org (Postfix, from userid 108) id F25B8C022; Sat, 22 Apr 2023 10:40:50 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682152850; bh=fmiVfF7XjOAyzByT51CixzO2cWUnuN4nSoCZntxTvEk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QOZoELBEiPEWSRqYNF9xE3Ml2EFrvW6//F3yKRElRhvFYyZLBFROvkkESYxmvfV2S m6VMEOSlGjMy6ViVN3BtUKxvFzcNMQQ3fWkNP58oTeuFMLmzt4CzUhePtdueYpdLHS t3L5anqSH0ur+jKlfFh6JDCu0qfqElqm7XfG9SKHrGUw6A/4W5xzHehoryKAgABE+T cE9rwNOO7u14eol9mvEyBEX9e7sk4W3RcTDWCkpo8gOVdBlkMhztkrbf/EaAPPb0v1 ya9cxkdHtwiPWVTau2o4rlJ+MKVjNnKCQmBaLJ35Vhp6DO7cmI2X9QrE5q5TC7kLAE GxNVrTZFBv8Ew== Received: from odin.codewreck.org (localhost [127.0.0.1]) by nautica.notk.org (Postfix) with ESMTPS id 89A6BC01D; Sat, 22 Apr 2023 10:40:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682152850; bh=fmiVfF7XjOAyzByT51CixzO2cWUnuN4nSoCZntxTvEk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QOZoELBEiPEWSRqYNF9xE3Ml2EFrvW6//F3yKRElRhvFYyZLBFROvkkESYxmvfV2S m6VMEOSlGjMy6ViVN3BtUKxvFzcNMQQ3fWkNP58oTeuFMLmzt4CzUhePtdueYpdLHS t3L5anqSH0ur+jKlfFh6JDCu0qfqElqm7XfG9SKHrGUw6A/4W5xzHehoryKAgABE+T cE9rwNOO7u14eol9mvEyBEX9e7sk4W3RcTDWCkpo8gOVdBlkMhztkrbf/EaAPPb0v1 ya9cxkdHtwiPWVTau2o4rlJ+MKVjNnKCQmBaLJ35Vhp6DO7cmI2X9QrE5q5TC7kLAE GxNVrTZFBv8Ew== Received: from [127.0.0.2] (localhost [::1]) by odin.codewreck.org (OpenSMTPD) with ESMTP id 2a928d4e; Sat, 22 Apr 2023 08:40:36 +0000 (UTC) From: Dominique Martinet Date: Sat, 22 Apr 2023 17:40:19 +0900 Subject: [PATCH RFC 2/2] io_uring: add support for getdents MIME-Version: 1.0 Message-Id: <20230422-uring-getdents-v1-2-14c1db36e98c@codewreck.org> References: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> In-Reply-To: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> To: Alexander Viro , Christian Brauner , Jens Axboe , Pavel Begunkov , Stefan Roesch Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, Dominique Martinet X-Mailer: b4 0.13-dev-f371f X-Developer-Signature: v=1; a=openpgp-sha256; l=4880; i=asmadeus@codewreck.org; h=from:subject:message-id; bh=N1xhUa8bfo36AvgC23A4t1KwwPLuIpzZO8R1HlkfPf0=; b=owEBbQKS/ZANAwAIAatOm+xqmOZwAcsmYgBkQ52EOlnH3HKltBNfDVzmnD4r4WTH+tQQrkcel JAQDo0Xl2eJAjMEAAEIAB0WIQT8g9txgG5a3TOhiE6rTpvsapjmcAUCZEOdhAAKCRCrTpvsapjm cB73EACEKl/hQl1z0FFKjzFHHmOZJqdnDUAKcV/gHp3wzcvYMlmMYFW9GCNVf8UjDhcJiMw9ieK NdSzqkUy3laPW8PAXun3UaEDiZzfeT04md0wyBJ/I9dqziCAs8JoJLwWaOuIeMB5T1ptOHxkkrF 5BWM2uHYLuCcQ466Jbn3GduMB4XGDO38iCJ9pNtTV6vuopKfU1M1GJkPmAchCvJFkzpSGTjwLRC 4PWiHvA+41ZivqLjEURhn83oM36ZRBoTM2kKmtpdsThG3dYLcYLHaam5mEq7cpOG7h+/pMoUWtx etOGTvy6qFv7YyrIGTrTTqJLU6A8Zxh+kspOmxi4X30ZChavMC/MKco5opU4rYvZkR5uw6NqmCf asAMwDte5Ghh/dFNvDdUBKcPCgEXWjimjSDBgV07toaE59AoeNCBb/by8GEFr75nSA+1pRiYqph kSgwJr4aDmSjyDrLOfkaZfHuFzgfbKVFhKZxUZFfADEbvA7A+0HJp0gMzpqa1b91HmEFfX89j+p RAF+DeXC1E3j2d6P8s+XrkUiBQgb2MpdhCuM5QgVHLVsrUglGuZEwayg37UhPSjCj0LUbgRCFc+ oCPiCj8higlig/latNSKq4tKgEUczLHtZ650GPbyRlaFDfwQ58J4rxUnnBJ2q6odQXSgS6Ezswv TO+Le3LXz/HiyWQ== X-Developer-Key: i=asmadeus@codewreck.org; a=openpgp; fpr=B894379F662089525B3FB1B9333F1F391BBBB00A Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 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. Additionally, since io_uring has no way of issuing a seek, a flag IORING_GETDENTS_REWIND has been added that will seek to the start of the directory like rewinddir(3) for users that might require such a thing. This will act exactly as if seek then getdents64 have been called sequentially with no atomicity guarantee: if this wasn't clear it is the responsibility of the caller to not use getdents multiple time on a single file in parallel if they want useful results, as is currently the case when using the syscall from multiple threads. Signed-off-by: Dominique Martinet --- include/uapi/linux/io_uring.h | 7 ++++++ io_uring/fs.c | 51 +++++++++++++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 +++ io_uring/opdef.c | 8 +++++++ 4 files changed, 69 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 709de6d4feb2..44c87fad2714 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 */ @@ -223,6 +224,7 @@ 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, @@ -258,6 +260,11 @@ 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..cb555bc738bd 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 +298,47 @@ 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); + gd->flags = READ_ONCE(sqe->getdents_flags); + if (gd->flags & ~IORING_GETDENTS_REWIND) + return -EINVAL; + + 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); + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + if ((gd->flags & IORING_GETDENTS_REWIND)) { + ret = vfs_llseek(req->file, 0, SEEK_SET); + if (ret < 0) + goto out; + } + + ret = vfs_getdents(req->file, gd->dirent, gd->count); +out: + if (ret < 0) { + if (ret == -ERESTARTSYS) + ret = -EINTR; + + req_set_fail(req); + } + + 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 cca7c5b55208..8f770c582ab3 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)