From mboxrd@z Thu Jan 1 00:00:00 1970 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 99D09C433F5 for ; Wed, 5 Jan 2022 13:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240348AbiAEN0w (ORCPT ); Wed, 5 Jan 2022 08:26:52 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:42308 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236846AbiAEN0t (ORCPT ); Wed, 5 Jan 2022 08:26:49 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9A443B81AA9 for ; Wed, 5 Jan 2022 13:26:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0152DC36AE0; Wed, 5 Jan 2022 13:26:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641389207; bh=3VrPmtUKxZoUuQhEpO5951inbuA0927G0nuskdZqz/c=; h=From:To:Cc:Subject:Date:From; b=CCKQHJZkRw7uE3xICF3R4SWMON5h656J4SzYNwIzEkFKK29RDAupQHbveIYa9U2S2 9UYSMjvYhy4X0rQwoRaHJsjXQsxB9gp9j3lH48xENdFvFcXiXnPGFnnpWUq3HtiWow WJ75yzOZTAa+LSLsNzkEWmgfCexM7M35kZm7+hklsXtAAwldLYJzUKsZhPU4aVkXHK AzWuF9tRBb74sc4UOlcf3Y+lAaUohLD9F9fr3fGocIKfYFgsUhGaTZFulyuXJmpNyn CG5vh5+eJlc5Y1h7AkfBlqoFFzmrOjMiev5f7cT18eLRnFHHvcgwH+vcWyHYnPKI5M NG+E0GhExZTiQ== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: idryomov@gmail.com, majianpeng Subject: [RFC PATCH] ceph: add new "nopagecache" option Date: Wed, 5 Jan 2022 08:26:45 -0500 Message-Id: <20220105132645.72282-1-jlayton@kernel.org> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org CephFS is a bit unlike most other filesystems in that it only conditionally does buffered I/O based on the caps that it gets from the MDS. In most cases, unless there is contended access for an inode the MDS does give Fbc caps to the client, so the unbuffered codepaths are only infrequently traveled and are difficult to test. At one time, the "-o sync" mount option would give you this behavior, but that was removed in commit 7ab9b3807097 ("ceph: Don't use ceph-sync-mode for synchronous-fs."). Add a new mount option to tell the client to ignore Fbc caps when doing I/O, and to use the synchronous codepaths exclusively, even on non-O_DIRECT file descriptors. We already have an ioctl that forces this behavior on a per-inode basis, so we can just always set the CEPH_F_SYNC flag on such mounts. Additionally, this patch also changes the client to not request Fbc when doing direct I/O. We aren't using the cache with O_DIRECT so we don't have any need for those caps. Cc: majianpeng Signed-off-by: Jeff Layton --- fs/ceph/file.c | 24 +++++++++++++++--------- fs/ceph/super.c | 11 +++++++++++ fs/ceph/super.h | 1 + 3 files changed, 27 insertions(+), 9 deletions(-) I've been working with this patch in order to test the synchronous codepaths for content encryption. I think though that this might make sense to take into mainline, as it could be helpful for troubleshooting, and ensuring that these codepaths are regularly tested. Either way, I think the cap handling changes probably make sense on their own. I can split that out if we don't want to take the mount option in as well. Thoughts? diff --git a/fs/ceph/file.c b/fs/ceph/file.c index c138e8126286..7de5db51c3d0 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -204,6 +204,8 @@ static int ceph_init_file_info(struct inode *inode, struct file *file, int fmode, bool isdir) { struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_mount_options *opt = + ceph_inode_to_client(&ci->vfs_inode)->mount_options; struct ceph_file_info *fi; dout("%s %p %p 0%o (%s)\n", __func__, inode, file, @@ -225,6 +227,9 @@ static int ceph_init_file_info(struct inode *inode, struct file *file, if (!fi) return -ENOMEM; + if (opt->flags & CEPH_MOUNT_OPT_NOPAGECACHE) + fi->flags |= CEPH_F_SYNC; + file->private_data = fi; } @@ -1536,7 +1541,7 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to) struct ceph_inode_info *ci = ceph_inode(inode); bool direct_lock = iocb->ki_flags & IOCB_DIRECT; ssize_t ret; - int want, got = 0; + int want = 0, got = 0; int retry_op = 0, read = 0; again: @@ -1551,13 +1556,14 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to) else ceph_start_io_read(inode); + if (!(fi->flags & CEPH_F_SYNC) && !direct_lock) + want |= CEPH_CAP_FILE_CACHE; if (fi->fmode & CEPH_FILE_MODE_LAZY) - want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO; - else - want = CEPH_CAP_FILE_CACHE; + want |= CEPH_CAP_FILE_LAZYIO; + ret = ceph_get_caps(filp, CEPH_CAP_FILE_RD, want, -1, &got); if (ret < 0) { - if (iocb->ki_flags & IOCB_DIRECT) + if (direct_lock) ceph_end_io_direct(inode); else ceph_end_io_read(inode); @@ -1691,7 +1697,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from) struct ceph_osd_client *osdc = &fsc->client->osdc; struct ceph_cap_flush *prealloc_cf; ssize_t count, written = 0; - int err, want, got; + int err, want = 0, got; bool direct_lock = false; u32 map_flags; u64 pool_flags; @@ -1766,10 +1772,10 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from) dout("aio_write %p %llx.%llx %llu~%zd getting caps. i_size %llu\n", inode, ceph_vinop(inode), pos, count, i_size_read(inode)); + if (!(fi->flags & CEPH_F_SYNC) && !direct_lock) + want |= CEPH_CAP_FILE_BUFFER; if (fi->fmode & CEPH_FILE_MODE_LAZY) - want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO; - else - want = CEPH_CAP_FILE_BUFFER; + want |= CEPH_CAP_FILE_LAZYIO; got = 0; err = ceph_get_caps(file, CEPH_CAP_FILE_WR, want, pos + count, &got); if (err < 0) diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 8d6daea351f6..d7e604a56fd9 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -160,6 +160,7 @@ enum { Opt_quotadf, Opt_copyfrom, Opt_wsync, + Opt_pagecache, }; enum ceph_recover_session_mode { @@ -201,6 +202,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = { fsparam_string ("mon_addr", Opt_mon_addr), fsparam_u32 ("wsize", Opt_wsize), fsparam_flag_no ("wsync", Opt_wsync), + fsparam_flag_no ("pagecache", Opt_pagecache), {} }; @@ -567,6 +569,12 @@ static int ceph_parse_mount_param(struct fs_context *fc, else fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS; break; + case Opt_pagecache: + if (result.negated) + fsopt->flags |= CEPH_MOUNT_OPT_NOPAGECACHE; + else + fsopt->flags &= ~CEPH_MOUNT_OPT_NOPAGECACHE; + break; default: BUG(); } @@ -702,6 +710,9 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root) if (!(fsopt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS)) seq_puts(m, ",wsync"); + if (fsopt->flags & CEPH_MOUNT_OPT_NOPAGECACHE) + seq_puts(m, ",nopagecache"); + if (fsopt->wsize != CEPH_MAX_WRITE_SIZE) seq_printf(m, ",wsize=%u", fsopt->wsize); if (fsopt->rsize != CEPH_MAX_READ_SIZE) diff --git a/fs/ceph/super.h b/fs/ceph/super.h index f9b1bbf26c1b..5c6d9384b7be 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -46,6 +46,7 @@ #define CEPH_MOUNT_OPT_NOQUOTADF (1<<13) /* no root dir quota in statfs */ #define CEPH_MOUNT_OPT_NOCOPYFROM (1<<14) /* don't use RADOS 'copy-from' op */ #define CEPH_MOUNT_OPT_ASYNC_DIROPS (1<<15) /* allow async directory ops */ +#define CEPH_MOUNT_OPT_NOPAGECACHE (1<<16) /* bypass pagecache altogether */ #define CEPH_MOUNT_OPT_DEFAULT \ (CEPH_MOUNT_OPT_DCACHE | \ -- 2.33.1