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bh=z3sOA+Wd5tRsdYNhOEn4oLwEz6sO/UZ9O0VL/asQvAk=; b=ABHAEyNhFdso4+ATXKOFSdq3z4S8Eq6m9BwaqH6xMTOJL0CvKmK2ftReT0c/napc+nJCNX Wp80JWt2fz7K7nQRQyq14N+YEpRFLIJShvty4qAi+kg1ZHpxHPAgMtyMCzVKMJkyP6Z91t XvqgnzxrJzxDsPwkc/GGcsKEQ+YaXoY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-589-15acLePuPo-nRv91oSUclQ-1; Mon, 22 May 2023 09:51:28 -0400 X-MC-Unique: 15acLePuPo-nRv91oSUclQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CC505185A78E; Mon, 22 May 2023 13:51:27 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id 03D3540CFD45; Mon, 22 May 2023 13:51:24 +0000 (UTC) From: David Howells To: Jens Axboe , Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Xiubo Li , Christoph Hellwig , Ilya Dryomov , ceph-devel@vger.kernel.org Subject: [PATCH v22 16/31] ceph: Provide a splice-read wrapper Date: Mon, 22 May 2023 14:50:03 +0100 Message-Id: <20230522135018.2742245-17-dhowells@redhat.com> In-Reply-To: <20230522135018.2742245-1-dhowells@redhat.com> References: <20230522135018.2742245-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Rspamd-Queue-Id: BBB70140005 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: jypaduzqm4qnosiwbwsi5j7f9agshidk X-HE-Tag: 1684763492-363305 X-HE-Meta: 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 hIxBvvl5 +We+IgsbsjM2LAkuiGUx6nvTS5wves19rqnQfKvlwgFUr/ebkbD/0YYeeMWrnKWo/O7TLiQ4/ajGsdR5Wq6WzeAff1hFIUO3vdzJzkFuS0/uTh82/bojP9NIqjuhPOofm3kcuBHjvFymn8NLy6El3acZ8ADkjDfHLAvq9zP3g0ArQumD/INnqvXR3grwacTnlxOTftxfgy2RqRfY5xW7fP70iyUC1kibRCtY++/hbbxQdLAD0JAZeQ2uE1W3j6yfGVPpYrYzTddYVy10K9KA1N0rStO/a+zdROj65nY/iSSDfd2Tm16NYkd6c5v8nyIlsdt5b2AY4ss8k62hlXOXX6m3/eHo3GW6khiXXT9PHhewtJnUnANDl1zxa8w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Provide a splice_read wrapper for Ceph. This does the inode shutdown check before proceeding and jumps to copy_splice_read() if the file has inline data or is a synchronous file. We try and get FILE_RD and either FILE_CACHE and/or FILE_LAZYIO caps and hold them across filemap_splice_read(). If we fail to get FILE_CACHE or FILE_LAZYIO capabilities, we use copy_splice_read() instead. Signed-off-by: David Howells Reviewed-by: Xiubo Li cc: Christoph Hellwig cc: Al Viro cc: Jens Axboe cc: Ilya Dryomov cc: Jeff Layton cc: ceph-devel@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-mm@kvack.org --- Notes: ver #21) - Need to drop the caps ref. - O_DIRECT is handled by the caller. fs/ceph/file.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 64 insertions(+), 1 deletion(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index f4d8bf7dec88..4285f6cb5d3b 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1745,6 +1745,69 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to) return ret; } +/* + * Wrap filemap_splice_read with checks for cap bits on the inode. + * Atomically grab references, so that those bits are not released + * back to the MDS mid-read. + */ +static ssize_t ceph_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags) +{ + struct ceph_file_info *fi = in->private_data; + struct inode *inode = file_inode(in); + struct ceph_inode_info *ci = ceph_inode(inode); + ssize_t ret; + int want = 0, got = 0; + CEPH_DEFINE_RW_CONTEXT(rw_ctx, 0); + + dout("splice_read %p %llx.%llx %llu~%zu trying to get caps on %p\n", + inode, ceph_vinop(inode), *ppos, len, inode); + + if (ceph_inode_is_shutdown(inode)) + return -ESTALE; + + if (ceph_has_inline_data(ci) || + (fi->flags & CEPH_F_SYNC)) + return copy_splice_read(in, ppos, pipe, len, flags); + + ceph_start_io_read(inode); + + want = CEPH_CAP_FILE_CACHE; + if (fi->fmode & CEPH_FILE_MODE_LAZY) + want |= CEPH_CAP_FILE_LAZYIO; + + ret = ceph_get_caps(in, CEPH_CAP_FILE_RD, want, -1, &got); + if (ret < 0) + goto out_end; + + if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) == 0) { + dout("splice_read/sync %p %llx.%llx %llu~%zu got cap refs on %s\n", + inode, ceph_vinop(inode), *ppos, len, + ceph_cap_string(got)); + + ceph_put_cap_refs(ci, got); + ceph_end_io_read(inode); + return copy_splice_read(in, ppos, pipe, len, flags); + } + + dout("splice_read %p %llx.%llx %llu~%zu got cap refs on %s\n", + inode, ceph_vinop(inode), *ppos, len, ceph_cap_string(got)); + + rw_ctx.caps = got; + ceph_add_rw_context(fi, &rw_ctx); + ret = filemap_splice_read(in, ppos, pipe, len, flags); + ceph_del_rw_context(fi, &rw_ctx); + + dout("splice_read %p %llx.%llx dropping cap refs on %s = %zd\n", + inode, ceph_vinop(inode), ceph_cap_string(got), ret); + + ceph_put_cap_refs(ci, got); +out_end: + ceph_end_io_read(inode); + return ret; +} + /* * Take cap references to avoid releasing caps to MDS mid-write. * @@ -2593,7 +2656,7 @@ const struct file_operations ceph_file_fops = { .lock = ceph_lock, .setlease = simple_nosetlease, .flock = ceph_flock, - .splice_read = generic_file_splice_read, + .splice_read = ceph_splice_read, .splice_write = iter_file_splice_write, .unlocked_ioctl = ceph_ioctl, .compat_ioctl = compat_ptr_ioctl,