From patchwork Thu Jun 20 17:31:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13705971 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 23C001BA863 for ; Thu, 20 Jun 2024 17:34:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718904861; cv=none; b=mZK7U9ozgWyrgtBu04Eyi746toD0KHCabjAIBKW+JPAGtY+FC0ZiOsBfnapmLzn7ygXTngbiAPcLD5pBemPfpjbFCA17El5H3T1/nnqZouJD13fl6jFFMH6i2dkchhWLCKV+YUhXTTq54dMdGA8xV4bj5yEIahv+xaq4Ml56kxA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718904861; c=relaxed/simple; bh=UPSCq7VGZv89byTbTB4i4NtDzE8lOeRtna8j2OEi1Fg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=km13wwaFwF9DlPAlEcnhoyX8alVxhnNXgA1no6RjVTY4CkBeKkVZnx18Fsfj8ZWHTFOTNId+676rE8Lb8UBtWwClJi6t4NJAiRhU1sntKj4+enQ6rQwB18Pk8IAoFx3sLae/E2OUJaf1Qb8HFkEIsZGsNMoOjVKBwKyL3EP1rIg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fOAV5Vji; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fOAV5Vji" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718904856; 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=uR+6EPlHTcAD9HukMoGDWtDn8rsvtq/nTdXRI0bZ5pY=; b=fOAV5VjiSd5LJOxbJkhGa1pTzPRKMcBICk/tM+iId0Fm77eGGQoS/byN5Obceuikp1Dnv1 WdkGsOnDjFJwrzr47o5XXiyQX0Z4Lail87I5LJ/tjrBV098UiZb9ADw2/76ZGCMifri8y+ nvBsbu9t+mn0PWLAkSeXdr2K0ZIe84E= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-169-Sc2_dRjRNFmQDYFmSMA_Lw-1; Thu, 20 Jun 2024 13:34:10 -0400 X-MC-Unique: Sc2_dRjRNFmQDYFmSMA_Lw-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D906619560B0; Thu, 20 Jun 2024 17:34:07 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.39.195.156]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4CE651956087; Thu, 20 Jun 2024 17:34:00 +0000 (UTC) From: David Howells To: Christian Brauner , Steve French , Matthew Wilcox Cc: David Howells , Jeff Layton , Gao Xiang , Dominique Martinet , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Eric Van Hensbergen , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 17/17] netfs: Speed up buffered reading Date: Thu, 20 Jun 2024 18:31:35 +0100 Message-ID: <20240620173137.610345-18-dhowells@redhat.com> In-Reply-To: <20240620173137.610345-1-dhowells@redhat.com> References: <20240620173137.610345-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 [!!!] NOTE: THIS PATCH IS INCOMPLETE! Buffered reading mostly works, but unbuffered/direct reads don't. Further, I have not yet re-implemented read-retry or tested local caching. Improve the efficiency of buffered reads in a number of ways: (1) Overhaul the algorithm in general so that it's a lot more compact and split the read submission code between buffered and unbuffered versions. The unbuffered version can be vastly simplified. (2) Get rid of ->clamp_length(), instead calling into ->issue_read() and having it return the size of the slice issued. This gets rid of a function pointer. (3) After determining the size of the slice it wants, ->issue_read() must call netfs_prepare_read_iterator() to load more folios into the buffer (if necessary) and to set the iterators. This allows some of the work to be done whilst I/O is in progress. (4) netfs_subreq_terminated(), which was used to report termination, is replaced with a function, netfs_read_subreq_progress(), that can be used to report incomplete progress as well as termination. afs can then use this to start unlocking pages as it fills them in as its transport has a packetised approach to RPCs rather than complete smaller messages favoured by, say, cifs. (5) Read-result collection is handed off to a work queue rather than being done in the I/O thread. Multiple subrequests can be processes simultaneously. (6) When a subrequest is collected, any folios it fully spans are collected and "spare" data on either side is donated to either the previous or the next subrequest in the sequence. Notes: (*) Readahead expansion is currently not working and needs investigation. (*) Unbuffered/direct-I/O reads don't work and need debugging. (*) Caching is untested and may not work. (*) Failed or partial reads need retrying, but aren't yet. (*) RDMA with cifs does appear to work, both with SIW and RXE. Signed-off-by: David Howells cc: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/9p/vfs_addr.c | 13 +- fs/afs/file.c | 18 +- fs/afs/fsclient.c | 9 +- fs/afs/yfsclient.c | 9 +- fs/ceph/addr.c | 72 ++--- fs/netfs/Makefile | 2 +- fs/netfs/buffered_read.c | 510 +++++++++++++++++++++------------ fs/netfs/direct_read.c | 99 ++++++- fs/netfs/internal.h | 6 - fs/netfs/io.c | 528 +---------------------------------- fs/netfs/iterator.c | 50 ++++ fs/netfs/main.c | 7 +- fs/netfs/objects.c | 1 - fs/netfs/read_collect.c | 450 +++++++++++++++++++++++++++++ fs/netfs/write_issue.c | 4 - fs/nfs/fscache.c | 31 +- fs/nfs/fscache.h | 7 +- fs/smb/client/cifssmb.c | 6 +- fs/smb/client/file.c | 69 +++-- fs/smb/client/smb2pdu.c | 8 +- include/linux/netfs.h | 19 +- include/trace/events/netfs.h | 82 +++++- 22 files changed, 1171 insertions(+), 829 deletions(-) create mode 100644 fs/netfs/read_collect.c diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index a97ceb105cd8..829a8215b870 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -64,12 +64,17 @@ static void v9fs_issue_write(struct netfs_io_subrequest *subreq) * v9fs_issue_read - Issue a read from 9P * @subreq: The read to make */ -static void v9fs_issue_read(struct netfs_io_subrequest *subreq) +static ssize_t v9fs_issue_read(struct netfs_io_subrequest *subreq) { struct netfs_io_request *rreq = subreq->rreq; struct p9_fid *fid = rreq->netfs_priv; + ssize_t len; int total, err; + len = netfs_prepare_read_iterator(subreq, ULONG_MAX, 0); + if (len < 0) + return len; + total = p9_client_read(fid, subreq->start + subreq->transferred, &subreq->io_iter, &err); @@ -77,7 +82,11 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq) * cache won't be on server and is zeroes */ __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); - netfs_subreq_terminated(subreq, err ?: total, false); + if (!err) + subreq->transferred += total; + + netfs_read_subreq_progress(subreq, err, false); + return len; } /** diff --git a/fs/afs/file.c b/fs/afs/file.c index addb106dba4c..54805a4c6d5c 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -243,7 +243,7 @@ static void afs_fetch_data_notify(struct afs_operation *op) req->error = error; if (subreq) { __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); - netfs_subreq_terminated(subreq, error ?: req->actual_len, false); + netfs_read_subreq_progress(subreq, error, false); req->subreq = NULL; } else if (req->done) { req->done(req); @@ -293,7 +293,7 @@ int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) op = afs_alloc_operation(req->key, vnode->volume); if (IS_ERR(op)) { if (req->subreq) - netfs_subreq_terminated(req->subreq, PTR_ERR(op), false); + netfs_read_subreq_progress(req->subreq, PTR_ERR(op), false); return PTR_ERR(op); } @@ -312,7 +312,7 @@ static void afs_read_worker(struct work_struct *work) fsreq = afs_alloc_read(GFP_NOFS); if (!fsreq) - return netfs_subreq_terminated(subreq, -ENOMEM, false); + return netfs_read_subreq_progress(subreq, -ENOMEM, false); fsreq->subreq = subreq; fsreq->pos = subreq->start + subreq->transferred; @@ -325,10 +325,16 @@ static void afs_read_worker(struct work_struct *work) afs_put_read(fsreq); } -static void afs_issue_read(struct netfs_io_subrequest *subreq) +static ssize_t afs_issue_read(struct netfs_io_subrequest *subreq) { - INIT_WORK(&subreq->work, afs_read_worker); - queue_work(system_long_wq, &subreq->work); + ssize_t len; + + len = netfs_prepare_read_iterator(subreq, ULONG_MAX, 0); + if (len > 0) { + INIT_WORK(&subreq->work, afs_read_worker); + queue_work(system_long_wq, &subreq->work); + } + return len; } static int afs_symlink_read_folio(struct file *file, struct folio *folio) diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index 79cd30775b7a..55165dc59039 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -304,6 +304,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) struct afs_vnode_param *vp = &op->file[0]; struct afs_read *req = op->fetch.req; const __be32 *bp; + size_t count_before; int ret; _enter("{%u,%zu,%zu/%llu}", @@ -345,10 +346,14 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) /* extract the returned data */ case 2: - _debug("extract data %zu/%llu", - iov_iter_count(call->iter), req->actual_len); + count_before = call->iov_len; + _debug("extract data %zu/%llu", count_before, req->actual_len); ret = afs_extract_data(call, true); + if (req->subreq) { + req->subreq->transferred += count_before - call->iov_len; + netfs_read_subreq_progress(req->subreq, -EINPROGRESS, false); + } if (ret < 0) return ret; diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c index f521e66d3bf6..33b1717e56a6 100644 --- a/fs/afs/yfsclient.c +++ b/fs/afs/yfsclient.c @@ -355,6 +355,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) struct afs_vnode_param *vp = &op->file[0]; struct afs_read *req = op->fetch.req; const __be32 *bp; + size_t count_before; int ret; _enter("{%u,%zu, %zu/%llu}", @@ -391,10 +392,14 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) /* extract the returned data */ case 2: - _debug("extract data %zu/%llu", - iov_iter_count(call->iter), req->actual_len); + count_before = call->iov_len; + _debug("extract data %zu/%llu", count_before, req->actual_len); ret = afs_extract_data(call, true); + if (req->subreq) { + req->subreq->transferred += count_before - call->iov_len; + netfs_read_subreq_progress(req->subreq, -EINPROGRESS, false); + } if (ret < 0) return ret; diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 8c16bc5250ef..7024dc58b363 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -205,21 +205,6 @@ static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq) } } -static bool ceph_netfs_clamp_length(struct netfs_io_subrequest *subreq) -{ - struct inode *inode = subreq->rreq->inode; - struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode); - struct ceph_inode_info *ci = ceph_inode(inode); - u64 objno, objoff; - u32 xlen; - - /* Truncate the extent at the end of the current block */ - ceph_calc_file_object_mapping(&ci->i_layout, subreq->start, subreq->len, - &objno, &objoff, &xlen); - subreq->len = min(xlen, fsc->mount_options->rsize); - return true; -} - static void finish_netfs_read(struct ceph_osd_request *req) { struct inode *inode = req->r_inode; @@ -263,7 +248,11 @@ static void finish_netfs_read(struct ceph_osd_request *req) calc_pages_for(osd_data->alignment, osd_data->length), false); } - netfs_subreq_terminated(subreq, err, false); + if (err > 0) { + subreq->transferred = err; + err = 0; + } + netfs_read_subreq_progress(subreq, err, false); iput(req->r_inode); ceph_dec_osd_stopping_blocker(fsc->mdsc); } @@ -277,7 +266,6 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq) struct ceph_mds_request *req; struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb); struct ceph_inode_info *ci = ceph_inode(inode); - struct iov_iter iter; ssize_t err = 0; size_t len; int mode; @@ -312,18 +300,21 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq) } len = min_t(size_t, iinfo->inline_len - subreq->start, subreq->len); - iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages, subreq->start, len); - err = copy_to_iter(iinfo->inline_data + subreq->start, len, &iter); - if (err == 0) + err = copy_to_iter(iinfo->inline_data + subreq->start, len, &subreq->io_iter); + if (err == 0) { err = -EFAULT; + } else { + subreq->transferred += err; + err = 0; + } ceph_mdsc_put_request(req); out: - netfs_subreq_terminated(subreq, err, false); + netfs_read_subreq_progress(subreq, err, false); return true; } -static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) +static ssize_t ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) { struct netfs_io_request *rreq = subreq->rreq; struct inode *inode = rreq->inode; @@ -332,9 +323,11 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) struct ceph_client *cl = fsc->client; struct ceph_osd_request *req = NULL; struct ceph_vino vino = ceph_vino(inode); - struct iov_iter iter; - int err = 0; - u64 len = subreq->len; + ssize_t slice = subreq->len; + int err; + u64 objno, objoff; + u32 xlen; + u64 len; bool sparse = IS_ENCRYPTED(inode) || ceph_test_mount_opt(fsc, SPARSEREAD); u64 off = subreq->start; int extent_cnt; @@ -344,9 +337,24 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) goto out; } - if (ceph_has_inline_data(ci) && ceph_netfs_issue_op_inline(subreq)) - return; + /* Truncate the extent at the end of the current block */ + ceph_calc_file_object_mapping(&ci->i_layout, subreq->start, subreq->len, + &objno, &objoff, &xlen); + xlen = umin(xlen, fsc->mount_options->rsize); + slice = netfs_prepare_read_iterator(subreq, xlen, 0); + if (slice < 0) + return slice; + + if (ceph_has_inline_data(ci) && ceph_netfs_issue_op_inline(subreq)) + return slice; + + // TODO: This rounding here is slightly dodgy. It *should* work, for + // now, as the cache only deals in blocks that are a multiple of + // PAGE_SIZE and fscrypt blocks are at most PAGE_SIZE. What needs to + // happen is for the fscrypt driving to be moved into netfslib and the + // data in the cache also to be stored encrypted. + len = slice; ceph_fscrypt_adjust_off_and_len(inode, &off, &len); req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, @@ -369,8 +377,6 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) doutc(cl, "%llx.%llx pos=%llu orig_len=%zu len=%llu\n", ceph_vinop(inode), subreq->start, subreq->len, len); - iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages, subreq->start, len); - /* * FIXME: For now, use CEPH_OSD_DATA_TYPE_PAGES instead of _ITER for * encrypted inodes. We'd need infrastructure that handles an iov_iter @@ -382,7 +388,7 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) struct page **pages; size_t page_off; - err = iov_iter_get_pages_alloc2(&iter, &pages, len, &page_off); + err = iov_iter_get_pages_alloc2(&subreq->io_iter, &pages, len, &page_off); if (err < 0) { doutc(cl, "%llx.%llx failed to allocate pages, %d\n", ceph_vinop(inode), err); @@ -397,7 +403,7 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false); } else { - osd_req_op_extent_osd_iter(req, 0, &iter); + osd_req_op_extent_osd_iter(req, 0, &subreq->io_iter); } if (!ceph_inc_osd_stopping_blocker(fsc->mdsc)) { err = -EIO; @@ -412,8 +418,9 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) out: ceph_osdc_put_request(req); if (err) - netfs_subreq_terminated(subreq, err, false); + netfs_read_subreq_progress(subreq, err, false); doutc(cl, "%llx.%llx result %d\n", ceph_vinop(inode), err); + return err < 0 ? err : slice; } static int ceph_init_request(struct netfs_io_request *rreq, struct file *file) @@ -493,7 +500,6 @@ const struct netfs_request_ops ceph_netfs_ops = { .free_request = ceph_netfs_free_request, .issue_read = ceph_netfs_issue_read, .expand_readahead = ceph_netfs_expand_readahead, - .clamp_length = ceph_netfs_clamp_length, .check_write_begin = ceph_netfs_check_write_begin, }; diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile index 8e6781e0b10b..0bd2996a2a77 100644 --- a/fs/netfs/Makefile +++ b/fs/netfs/Makefile @@ -5,12 +5,12 @@ netfs-y := \ buffered_write.o \ direct_read.o \ direct_write.o \ - io.o \ iterator.o \ locking.o \ main.o \ misc.o \ objects.o \ + read_collect.o \ write_collect.o \ write_issue.o diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c index a6bb03bea920..aabe79df765a 100644 --- a/fs/netfs/buffered_read.c +++ b/fs/netfs/buffered_read.c @@ -9,126 +9,6 @@ #include #include "internal.h" -/* - * Unlock the folios in a read operation. We need to set PG_writeback on any - * folios we're going to write back before we unlock them. - * - * Note that if the deprecated NETFS_RREQ_USE_PGPRIV2 is set then we use - * PG_private_2 and do a direct write to the cache from here instead. - */ -void netfs_rreq_unlock_folios(struct netfs_io_request *rreq) -{ - struct netfs_io_subrequest *subreq; - struct netfs_folio *finfo; - struct folio *folio; - pgoff_t start_page = rreq->start / PAGE_SIZE; - pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1; - size_t account = 0; - bool subreq_failed = false; - - XA_STATE(xas, &rreq->mapping->i_pages, start_page); - - if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) { - __clear_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags); - list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { - __clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); - } - } - - /* Walk through the pagecache and the I/O request lists simultaneously. - * We may have a mixture of cached and uncached sections and we only - * really want to write out the uncached sections. This is slightly - * complicated by the possibility that we might have huge pages with a - * mixture inside. - */ - subreq = list_first_entry(&rreq->subrequests, - struct netfs_io_subrequest, rreq_link); - subreq_failed = (subreq->error < 0); - - trace_netfs_rreq(rreq, netfs_rreq_trace_unlock); - - rcu_read_lock(); - xas_for_each(&xas, folio, last_page) { - loff_t pg_end; - bool pg_failed = false; - bool wback_to_cache = false; - bool folio_started = false; - - if (xas_retry(&xas, folio)) - continue; - - pg_end = folio_pos(folio) + folio_size(folio) - 1; - - for (;;) { - loff_t sreq_end; - - if (!subreq) { - pg_failed = true; - break; - } - if (test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags)) { - if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE, - &subreq->flags)) { - trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); - folio_start_private_2(folio); - folio_started = true; - } - } else { - wback_to_cache |= - test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); - } - pg_failed |= subreq_failed; - sreq_end = subreq->start + subreq->len - 1; - if (pg_end < sreq_end) - break; - - account += subreq->transferred; - if (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) { - subreq = list_next_entry(subreq, rreq_link); - subreq_failed = (subreq->error < 0); - } else { - subreq = NULL; - subreq_failed = false; - } - - if (pg_end == sreq_end) - break; - } - - if (!pg_failed) { - flush_dcache_folio(folio); - finfo = netfs_folio_info(folio); - if (finfo) { - trace_netfs_folio(folio, netfs_folio_trace_filled_gaps); - if (finfo->netfs_group) - folio_change_private(folio, finfo->netfs_group); - else - folio_detach_private(folio); - kfree(finfo); - } - folio_mark_uptodate(folio); - if (wback_to_cache && !WARN_ON_ONCE(folio_get_private(folio) != NULL)) { - trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); - folio_attach_private(folio, NETFS_FOLIO_COPY_TO_CACHE); - filemap_dirty_folio(folio->mapping, folio); - } - } - - if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) { - if (folio->index == rreq->no_unlock_folio && - test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags)) - _debug("no unlock"); - else - folio_unlock(folio); - } - } - rcu_read_unlock(); - - task_io_account_read(account); - if (rreq->netfs_ops->done) - rreq->netfs_ops->done(rreq); -} - static void netfs_cache_expand_readahead(struct netfs_io_request *rreq, unsigned long long *_start, unsigned long long *_len, @@ -183,6 +63,278 @@ static int netfs_begin_cache_read(struct netfs_io_request *rreq, struct netfs_in return fscache_begin_read_operation(&rreq->cache_resources, netfs_i_cookie(ctx)); } +/* + * Decant the list of folios to read into a rolling buffer. + */ +static size_t netfs_load_buffer_from_ra(struct netfs_io_request *rreq, + struct sheaf *sheaf) +{ + unsigned int order, nr; + size_t size = 0; + + nr = __readahead_batch(rreq->ractl, (struct page **)sheaf->slots, + ARRAY_SIZE(sheaf->slots)); + for (int i = 0; i < nr; i++) { + struct folio *folio = sheaf_slot_folio(sheaf, i); + + trace_netfs_folio(folio, netfs_folio_trace_read); + order = folio_order(folio); + sheaf->orders[i] = order; + size += PAGE_SIZE << order; + } + + for (int i = nr; i < ARRAY_SIZE(sheaf->slots); i++) + sheaf_slot_set(sheaf, i, NULL); + + return size; +} + +/** + * netfs_prepare_read_iterator - Prepare the subreq iterator for I/O + * @subreq: The subrequest to be set up + * @rsize: Preferred (and maximum) size + * @max_segs: Maximum number of DMA segments (or 0) + * + * Prepare the I/O iterator representing the read buffer on a subrequest for + * the filesystem to use for I/O (it can be passed directly to a socket). This + * is intended to be called from the ->issue_read() method once the filesystem + * has trimmed the request to the size it wants. + * + * Returns the limited size if successful and -ENOMEM if insufficient memory + * available. + * + * [!] NOTE: This must be run in the same thread as ->issue_read() was called + * in as we access the readahead_control struct. + */ +ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq, size_t rsize, + unsigned int max_segs) +{ + struct netfs_io_request *rreq = subreq->rreq; + + rsize = umin(subreq->len, rsize); + + if (rreq->ractl) { + /* If we don't have sufficient folios in the rolling buffer, + * extract a sheaf's worth from the readahead region at a time + * into the buffer. Note that this acquires a ref on each page + * that we will need to release later - but we don't want to do + * that until after we've started the I/O. + */ + while (rreq->submitted < subreq->start + rsize) { + struct sheaf *tail = rreq->buffer_tail, *new; + size_t added; + + new = kmalloc(sizeof(*new), GFP_NOFS); + if (!new) + return -ENOMEM; + netfs_stat(&netfs_n_sheaf); + new->next = NULL; + new->prev = tail; + tail->next = new; + rreq->buffer_tail = new; + added = netfs_load_buffer_from_ra(rreq, new); + rreq->iter.count += added; + rreq->submitted += added; + } + } + + subreq->len = rsize; + if (unlikely(max_segs)) { + size_t limit = netfs_limit_iter(&rreq->iter, 0, rsize, max_segs); + + if (limit < rsize) { + subreq->len = limit; + trace_netfs_sreq(subreq, netfs_sreq_trace_limited); + } + } + + subreq->io_iter = rreq->iter; + + trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); + + if (iov_iter_is_sheaf(&subreq->io_iter)) { + subreq->curr_sheaf = (struct sheaf *)subreq->io_iter.sheaf; + subreq->curr_sheaf_slot = subreq->io_iter.sheaf_slot; + subreq->curr_folio_order = subreq->curr_sheaf->orders[subreq->curr_sheaf_slot]; + } + + iov_iter_truncate(&subreq->io_iter, subreq->len); + iov_iter_advance(&rreq->iter, subreq->len); + return subreq->len; +} +EXPORT_SYMBOL(netfs_prepare_read_iterator); + +static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq, + loff_t i_size) +{ + struct netfs_cache_resources *cres = &rreq->cache_resources; + + if (!cres->ops) + return NETFS_DOWNLOAD_FROM_SERVER; + return cres->ops->prepare_read(subreq, i_size); +} + +static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, + bool was_async) +{ + struct netfs_io_subrequest *subreq = priv; + + if (transferred_or_error < 0) + netfs_read_subreq_progress(subreq, transferred_or_error, was_async); + + if (transferred_or_error > 0) + subreq->transferred += transferred_or_error; + netfs_read_subreq_progress(subreq, 0, was_async); +} + +/* + * Issue a read against the cache. + * - Eats the caller's ref on subreq. + */ +static ssize_t netfs_read_cache_to_pagecache(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq) +{ + struct netfs_cache_resources *cres = &rreq->cache_resources; + ssize_t slice = subreq->len; + + netfs_stat(&netfs_n_rh_read); + cres->ops->read(cres, subreq->start, &subreq->io_iter, NETFS_READ_HOLE_IGNORE, + netfs_cache_read_terminated, subreq); + return slice; +} + +/* + * Perform a read to the pagecache from a series of sources of different types, + * slicing up the region to be read according to available cache blocks and + * network rsize. + */ +static int netfs_read_to_pagecache(struct netfs_io_request *rreq) +{ + struct netfs_inode *ictx = netfs_inode(rreq->inode); + unsigned long long start = rreq->start; + ssize_t size = rreq->len; + + /* Chop the readahead request up into subrequests. */ + do { + struct netfs_io_subrequest *subreq; + enum netfs_io_source source = NETFS_DOWNLOAD_FROM_SERVER; + ssize_t slice; + + subreq = netfs_alloc_subrequest(rreq); + if (!subreq) + return -ENOMEM; + + subreq->source = NETFS_DOWNLOAD_FROM_SERVER; + subreq->start = start; + subreq->len = size; + + spin_lock(&rreq->lock); + list_add_tail(&subreq->rreq_link, &rreq->subrequests); + subreq->prev_donated = rreq->prev_donated; + rreq->prev_donated = 0; + trace_netfs_sreq(subreq, netfs_sreq_trace_added); + spin_unlock(&rreq->lock); + + source = netfs_cache_prepare_read(rreq, subreq, rreq->i_size); + if (source == NETFS_DOWNLOAD_FROM_SERVER) { + if (subreq->start >= ictx->zero_point) { + subreq->source = source = NETFS_FILL_WITH_ZEROES; + goto fill_with_zeroes; + } + + if (subreq->len > ictx->zero_point - subreq->start) + subreq->len = ictx->zero_point - subreq->start; + if (subreq->len > rreq->i_size - subreq->start) + subreq->len = rreq->i_size - subreq->start; + + netfs_stat(&netfs_n_rh_download); + slice = rreq->netfs_ops->issue_read(subreq); + if (slice <= 0) + return slice; + goto done; + } + + fill_with_zeroes: + if (source == NETFS_FILL_WITH_ZEROES) { + subreq->source = NETFS_FILL_WITH_ZEROES; + trace_netfs_sreq(subreq, netfs_sreq_trace_submit); + netfs_stat(&netfs_n_rh_zero); + slice = subreq->len; + subreq->transferred = slice; + __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); + netfs_read_subreq_progress(subreq, 0, false); + goto done; + } + + if (source == NETFS_READ_FROM_CACHE) { + trace_netfs_sreq(subreq, netfs_sreq_trace_submit); + slice = netfs_read_cache_to_pagecache(rreq, subreq); + goto done; + } + + if (source == NETFS_INVALID_READ) + break; + + done: + size -= slice; + start += slice; + cond_resched(); + } while (size > 0); + + return 0; +} + +/* + * Set up the initial sheaf of buffer folios in the rolling buffer and set the + * iterator to refer to it. + */ +static int netfs_prime_buffer(struct netfs_io_request *rreq) +{ + struct sheaf *sheaf; + size_t added; + + sheaf = kmalloc(sizeof(*sheaf), GFP_KERNEL); + if (!sheaf) + return -ENOMEM; + netfs_stat(&netfs_n_sheaf); + sheaf->next = NULL; + sheaf->prev = NULL; + rreq->buffer = sheaf; + rreq->buffer_tail = sheaf; + rreq->submitted = rreq->start; + iov_iter_sheaf(&rreq->iter, ITER_DEST, sheaf, 0, 0, 0); + + added = netfs_load_buffer_from_ra(rreq, sheaf); + rreq->iter.count += added; + rreq->submitted += added; + return 0; +} + +/* + * Drop the ref on each folio that we inherited from the VM readahead code. We + * still have the folio locks to pin the page until we complete the I/O. + */ +static void netfs_put_ra_refs(struct sheaf *sheaf) +{ + struct folio_batch fbatch; + + folio_batch_init(&fbatch); + while (sheaf) { + for (unsigned int slot = 0; slot < sheaf_nr_slots(sheaf); slot++) { + if (!sheaf->slots[slot]) + continue; + trace_netfs_folio(sheaf_slot_folio(sheaf, slot), + netfs_folio_trace_read_put); + if (!folio_batch_add(&fbatch, sheaf_slot_folio(sheaf, slot))) + folio_batch_release(&fbatch); + } + sheaf = sheaf->next; + } + + folio_batch_release(&fbatch); +} + /** * netfs_readahead - Helper to manage a read request * @ractl: The description of the readahead request @@ -201,22 +353,17 @@ static int netfs_begin_cache_read(struct netfs_io_request *rreq, struct netfs_in void netfs_readahead(struct readahead_control *ractl) { struct netfs_io_request *rreq; - struct netfs_inode *ctx = netfs_inode(ractl->mapping->host); + struct netfs_inode *ictx = netfs_inode(ractl->mapping->host); + unsigned long long start = readahead_pos(ractl); + size_t size = readahead_length(ractl); int ret; - _enter("%lx,%x", readahead_index(ractl), readahead_count(ractl)); - - if (readahead_count(ractl) == 0) - return; - - rreq = netfs_alloc_request(ractl->mapping, ractl->file, - readahead_pos(ractl), - readahead_length(ractl), + rreq = netfs_alloc_request(ractl->mapping, ractl->file, start, size, NETFS_READAHEAD); if (IS_ERR(rreq)) return; - ret = netfs_begin_cache_read(rreq, ctx); + ret = netfs_begin_cache_read(rreq, ictx); if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS) goto cleanup_free; @@ -224,20 +371,17 @@ void netfs_readahead(struct readahead_control *ractl) trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl), netfs_read_trace_readahead); - netfs_rreq_expand(rreq, ractl); + //netfs_rreq_expand(rreq, ractl); - /* Set up the output buffer */ - iov_iter_xarray(&rreq->iter, ITER_DEST, &ractl->mapping->i_pages, - rreq->start, rreq->len); + rreq->ractl = ractl; + if (netfs_prime_buffer(rreq) < 0) + goto cleanup_free; + netfs_read_to_pagecache(rreq); - /* Drop the refs on the folios here rather than in the cache or - * filesystem. The locks will be dropped in netfs_rreq_unlock(). - */ - while (readahead_folio(ractl)) - ; + /* Release the folio refs whilst we're waiting for the I/O. */ + netfs_put_ra_refs(rreq->buffer); - netfs_begin_read(rreq, false); - netfs_put_request(rreq, false, netfs_rreq_trace_put_return); + netfs_put_request(rreq, true, netfs_rreq_trace_put_return); return; cleanup_free: @@ -246,6 +390,30 @@ void netfs_readahead(struct readahead_control *ractl) } EXPORT_SYMBOL(netfs_readahead); +/* + * Create a rolling buffer with a single occupying folio. + */ +static int netfs_create_singular_buffer(struct netfs_io_request *rreq, struct folio *folio) +{ + struct sheaf *sheaf; + + sheaf = kzalloc(sizeof(*sheaf), GFP_KERNEL); + if (!sheaf) + return -ENOMEM; + + netfs_stat(&netfs_n_sheaf); + sheaf->next = NULL; + sheaf->prev = NULL; + sheaf_slot_set_folio(sheaf, 0, folio); + sheaf->orders[0] = folio_order(folio); + rreq->buffer = sheaf; + rreq->buffer_tail = sheaf; + rreq->submitted = rreq->start + rreq->len; + iov_iter_sheaf(&rreq->iter, ITER_DEST, sheaf, 0, 0, rreq->len); + rreq->ractl = (struct readahead_control *)1UL; + return 0; +} + /** * netfs_read_folio - Helper to manage a read_folio request * @file: The file to read from @@ -326,14 +494,28 @@ int netfs_read_folio(struct file *file, struct folio *folio) if (to < flen) bvec_set_folio(&bvec[i++], folio, flen - to, to); iov_iter_bvec(&rreq->iter, ITER_DEST, bvec, i, rreq->len); + + ret = netfs_read_to_pagecache(rreq); + + if (sink) + folio_put(sink); } else { - iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages, - rreq->start, rreq->len); + ret = netfs_create_singular_buffer(rreq, folio); + if (ret < 0) + goto discard; + + ret = netfs_read_to_pagecache(rreq); + } + + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip); + wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS, TASK_UNINTERRUPTIBLE); + if (ret == 0) + ret = rreq->error; + if (ret == 0 && rreq->submitted < rreq->len) { + trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); + ret = -EIO; } - ret = netfs_begin_read(rreq, true); - if (sink) - folio_put(sink); netfs_put_request(rreq, false, netfs_rreq_trace_put_return); return ret < 0 ? ret : 0; @@ -395,7 +577,7 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len, } /** - * netfs_write_begin - Helper to prepare for writing + * netfs_write_begin - Helper to prepare for writing [DEPRECATED] * @ctx: The netfs context * @file: The file to read from * @mapping: The mapping to read from @@ -406,13 +588,10 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len, * * Pre-read data for a write-begin request by drawing data from the cache if * possible, or the netfs if not. Space beyond the EOF is zero-filled. - * Multiple I/O requests from different sources will get munged together. If - * necessary, the readahead window can be expanded in either direction to a - * more convenient alighment for RPC efficiency or to make storage in the cache - * feasible. + * Multiple I/O requests from different sources will get munged together. * * The calling netfs must provide a table of operations, only one of which, - * issue_op, is mandatory. + * issue_read, is mandatory. * * The check_write_begin() operation can be provided to check for and flush * conflicting writes once the folio is grabbed and locked. It is passed a @@ -437,8 +616,6 @@ int netfs_write_begin(struct netfs_inode *ctx, pgoff_t index = pos >> PAGE_SHIFT; int ret; - DEFINE_READAHEAD(ractl, file, NULL, mapping, index); - retry: folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN, mapping_gfp_mask(mapping)); @@ -486,22 +663,12 @@ int netfs_write_begin(struct netfs_inode *ctx, netfs_stat(&netfs_n_rh_write_begin); trace_netfs_read(rreq, pos, len, netfs_read_trace_write_begin); - /* Expand the request to meet caching requirements and download - * preferences. - */ - ractl._nr_pages = folio_nr_pages(folio); - netfs_rreq_expand(rreq, &ractl); - /* Set up the output buffer */ - iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages, - rreq->start, rreq->len); - - /* We hold the folio locks, so we can drop the references */ - folio_get(folio); - while (readahead_folio(&ractl)) - ; + ret = netfs_create_singular_buffer(rreq, folio); + if (ret < 0) + goto error_put; - ret = netfs_begin_read(rreq, true); + ret = netfs_read_to_pagecache(rreq); if (ret < 0) goto error; netfs_put_request(rreq, false, netfs_rreq_trace_put_return); @@ -557,10 +724,11 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio, trace_netfs_read(rreq, start, flen, netfs_read_trace_prefetch_for_write); /* Set up the output buffer */ - iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages, - rreq->start, rreq->len); + ret = netfs_create_singular_buffer(rreq, folio); + if (ret < 0) + goto error_put; - ret = netfs_begin_read(rreq, true); + ret = netfs_read_to_pagecache(rreq); netfs_put_request(rreq, false, netfs_rreq_trace_put_return); return ret; diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c index 10a1e4da6bda..24a74eb25466 100644 --- a/fs/netfs/direct_read.c +++ b/fs/netfs/direct_read.c @@ -16,6 +16,103 @@ #include #include "internal.h" +/* + * Perform a read to a buffer from the server, slicing up the region to be read + * according to the network rsize. + */ +static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) +{ + unsigned long long start = rreq->start; + ssize_t size = rreq->len; + + do { + struct netfs_io_subrequest *subreq; + ssize_t slice; + + subreq = netfs_alloc_subrequest(rreq); + if (!subreq) + return -ENOMEM; + + subreq->source = NETFS_DOWNLOAD_FROM_SERVER; + subreq->start = start; + subreq->len = size; + + spin_lock(&rreq->lock); + list_add_tail(&subreq->rreq_link, &rreq->subrequests); + subreq->prev_donated = rreq->prev_donated; + rreq->prev_donated = 0; + trace_netfs_sreq(subreq, netfs_sreq_trace_added); + spin_unlock(&rreq->lock); + + if (subreq->len > rreq->i_size - subreq->start) + subreq->len = rreq->i_size - subreq->start; + + netfs_stat(&netfs_n_rh_download); + slice = rreq->netfs_ops->issue_read(subreq); + if (slice <= 0) + return slice; + + size -= slice; + start += slice; + + if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) && + test_bit(NETFS_RREQ_NONBLOCK, &rreq->flags)) + break; + cond_resched(); + } while (size > 0); + + return 0; +} + +/* + * Perform a read to an application buffer, bypassing the pagecache and the + * local disk cache. + */ +static int netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync) +{ + int ret; + + kenter("R=%x %llx-%llx", + rreq->debug_id, rreq->start, rreq->start + rreq->len - 1); + + if (rreq->len == 0) { + pr_err("Zero-sized read [R=%x]\n", rreq->debug_id); + return -EIO; + } + + // TODO: Use bounce buffer if requested + + inode_dio_begin(rreq->inode); + + ret = netfs_dispatch_unbuffered_reads(rreq); + + if (!rreq->submitted) { + netfs_put_request(rreq, false, netfs_rreq_trace_put_no_submit); + inode_dio_end(rreq->inode); + ret = 0; + goto out; + } + + if (sync) { + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip); + wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS, + TASK_UNINTERRUPTIBLE); + + ret = rreq->error; + if (ret == 0 && rreq->submitted < rreq->len && + rreq->origin != NETFS_DIO_READ) { + trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); + ret = -EIO; + } + } else { + ret = -EIOCBQUEUED; + } + +out: + kleave(" = %d", ret); + return ret; +} + /** * netfs_unbuffered_read_iter_locked - Perform an unbuffered or direct I/O read * @iocb: The I/O control descriptor describing the read @@ -81,7 +178,7 @@ ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *i if (async) rreq->iocb = iocb; - ret = netfs_begin_read(rreq, is_sync_kiocb(iocb)); + ret = netfs_unbuffered_read(rreq, is_sync_kiocb(iocb)); if (ret < 0) goto out; /* May be -EIOCBQUEUED */ if (!async) { diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index fe0974a95152..c470857bfcf8 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -23,15 +23,9 @@ /* * buffered_read.c */ -void netfs_rreq_unlock_folios(struct netfs_io_request *rreq); int netfs_prefetch_for_write(struct file *file, struct folio *folio, size_t offset, size_t len); -/* - * io.c - */ -int netfs_begin_read(struct netfs_io_request *rreq, bool sync); - /* * main.c */ diff --git a/fs/netfs/io.c b/fs/netfs/io.c index 27dbea0f3867..84392eed87ee 100644 --- a/fs/netfs/io.c +++ b/fs/netfs/io.c @@ -16,88 +16,7 @@ #include #include "internal.h" -/* - * Clear the unread part of an I/O request. - */ -static void netfs_clear_unread(struct netfs_io_subrequest *subreq) -{ - iov_iter_zero(iov_iter_count(&subreq->io_iter), &subreq->io_iter); -} - -static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, - bool was_async) -{ - struct netfs_io_subrequest *subreq = priv; - - netfs_subreq_terminated(subreq, transferred_or_error, was_async); -} - -/* - * Issue a read against the cache. - * - Eats the caller's ref on subreq. - */ -static void netfs_read_from_cache(struct netfs_io_request *rreq, - struct netfs_io_subrequest *subreq, - enum netfs_read_from_hole read_hole) -{ - struct netfs_cache_resources *cres = &rreq->cache_resources; - - netfs_stat(&netfs_n_rh_read); - cres->ops->read(cres, subreq->start, &subreq->io_iter, read_hole, - netfs_cache_read_terminated, subreq); -} - -/* - * Fill a subrequest region with zeroes. - */ -static void netfs_fill_with_zeroes(struct netfs_io_request *rreq, - struct netfs_io_subrequest *subreq) -{ - netfs_stat(&netfs_n_rh_zero); - __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); - netfs_subreq_terminated(subreq, 0, false); -} - -/* - * Ask the netfs to issue a read request to the server for us. - * - * The netfs is expected to read from subreq->pos + subreq->transferred to - * subreq->pos + subreq->len - 1. It may not backtrack and write data into the - * buffer prior to the transferred point as it might clobber dirty data - * obtained from the cache. - * - * Alternatively, the netfs is allowed to indicate one of two things: - * - * - NETFS_SREQ_SHORT_READ: A short read - it will get called again to try and - * make progress. - * - * - NETFS_SREQ_CLEAR_TAIL: A short read - the rest of the buffer will be - * cleared. - */ -static void netfs_read_from_server(struct netfs_io_request *rreq, - struct netfs_io_subrequest *subreq) -{ - netfs_stat(&netfs_n_rh_download); - - if (rreq->origin != NETFS_DIO_READ && - iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred) - pr_warn("R=%08x[%u] ITER PRE-MISMATCH %zx != %zx-%zx %lx\n", - rreq->debug_id, subreq->debug_index, - iov_iter_count(&subreq->io_iter), subreq->len, - subreq->transferred, subreq->flags); - rreq->netfs_ops->issue_read(subreq); -} - -/* - * Release those waiting. - */ -static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async) -{ - trace_netfs_rreq(rreq, netfs_rreq_trace_done); - netfs_clear_subrequests(rreq, was_async); - netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete); -} - +#if 0 /* * Handle a short read. */ @@ -162,8 +81,6 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq) __clear_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags); list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { if (subreq->error) { - if (subreq->source != NETFS_READ_FROM_CACHE) - break; subreq->source = NETFS_DOWNLOAD_FROM_SERVER; subreq->error = 0; netfs_stat(&netfs_n_rh_download_instead); @@ -203,445 +120,4 @@ static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq) } } } - -/* - * Determine how much we can admit to having read from a DIO read. - */ -static void netfs_rreq_assess_dio(struct netfs_io_request *rreq) -{ - struct netfs_io_subrequest *subreq; - unsigned int i; - size_t transferred = 0; - - for (i = 0; i < rreq->direct_bv_count; i++) { - flush_dcache_page(rreq->direct_bv[i].bv_page); - // TODO: cifs marks pages in the destination buffer - // dirty under some circumstances after a read. Do we - // need to do that too? - set_page_dirty(rreq->direct_bv[i].bv_page); - } - - list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { - if (subreq->error || subreq->transferred == 0) - break; - transferred += subreq->transferred; - if (subreq->transferred < subreq->len) - break; - } - - for (i = 0; i < rreq->direct_bv_count; i++) - flush_dcache_page(rreq->direct_bv[i].bv_page); - - rreq->transferred = transferred; - task_io_account_read(transferred); - - if (rreq->iocb) { - rreq->iocb->ki_pos += transferred; - if (rreq->iocb->ki_complete) - rreq->iocb->ki_complete( - rreq->iocb, rreq->error ? rreq->error : transferred); - } - if (rreq->netfs_ops->done) - rreq->netfs_ops->done(rreq); - inode_dio_end(rreq->inode); -} - -/* - * Assess the state of a read request and decide what to do next. - * - * Note that we could be in an ordinary kernel thread, on a workqueue or in - * softirq context at this point. We inherit a ref from the caller. - */ -static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async) -{ - trace_netfs_rreq(rreq, netfs_rreq_trace_assess); - -again: - netfs_rreq_is_still_valid(rreq); - - if (!test_bit(NETFS_RREQ_FAILED, &rreq->flags) && - test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags)) { - if (netfs_rreq_perform_resubmissions(rreq)) - goto again; - return; - } - - if (rreq->origin != NETFS_DIO_READ) - netfs_rreq_unlock_folios(rreq); - else - netfs_rreq_assess_dio(rreq); - - trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip); - clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags); - wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS); - - netfs_rreq_completed(rreq, was_async); -} - -static void netfs_rreq_work(struct work_struct *work) -{ - struct netfs_io_request *rreq = - container_of(work, struct netfs_io_request, work); - netfs_rreq_assess(rreq, false); -} - -/* - * Handle the completion of all outstanding I/O operations on a read request. - * We inherit a ref from the caller. - */ -static void netfs_rreq_terminated(struct netfs_io_request *rreq, - bool was_async) -{ - if (test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags) && - was_async) { - if (!queue_work(system_unbound_wq, &rreq->work)) - BUG(); - } else { - netfs_rreq_assess(rreq, was_async); - } -} - -/** - * netfs_subreq_terminated - Note the termination of an I/O operation. - * @subreq: The I/O request that has terminated. - * @transferred_or_error: The amount of data transferred or an error code. - * @was_async: The termination was asynchronous - * - * This tells the read helper that a contributory I/O operation has terminated, - * one way or another, and that it should integrate the results. - * - * The caller indicates in @transferred_or_error the outcome of the operation, - * supplying a positive value to indicate the number of bytes transferred, 0 to - * indicate a failure to transfer anything that should be retried or a negative - * error code. The helper will look after reissuing I/O operations as - * appropriate and writing downloaded data to the cache. - * - * If @was_async is true, the caller might be running in softirq or interrupt - * context and we can't sleep. - */ -void netfs_subreq_terminated(struct netfs_io_subrequest *subreq, - ssize_t transferred_or_error, - bool was_async) -{ - struct netfs_io_request *rreq = subreq->rreq; - int u; - - _enter("R=%x[%x]{%llx,%lx},%zd", - rreq->debug_id, subreq->debug_index, - subreq->start, subreq->flags, transferred_or_error); - - switch (subreq->source) { - case NETFS_READ_FROM_CACHE: - netfs_stat(&netfs_n_rh_read_done); - break; - case NETFS_DOWNLOAD_FROM_SERVER: - netfs_stat(&netfs_n_rh_download_done); - break; - default: - break; - } - - if (IS_ERR_VALUE(transferred_or_error)) { - subreq->error = transferred_or_error; - trace_netfs_failure(rreq, subreq, transferred_or_error, - netfs_fail_read); - goto failed; - } - - if (WARN(transferred_or_error > subreq->len - subreq->transferred, - "Subreq overread: R%x[%x] %zd > %zu - %zu", - rreq->debug_id, subreq->debug_index, - transferred_or_error, subreq->len, subreq->transferred)) - transferred_or_error = subreq->len - subreq->transferred; - - subreq->error = 0; - subreq->transferred += transferred_or_error; - if (subreq->transferred < subreq->len) - goto incomplete; - -complete: - __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags); - if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) - set_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags); - -out: - trace_netfs_sreq(subreq, netfs_sreq_trace_terminated); - - /* If we decrement nr_outstanding to 0, the ref belongs to us. */ - u = atomic_dec_return(&rreq->nr_outstanding); - if (u == 0) - netfs_rreq_terminated(rreq, was_async); - else if (u == 1) - wake_up_var(&rreq->nr_outstanding); - - netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated); - return; - -incomplete: - if (test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags)) { - netfs_clear_unread(subreq); - subreq->transferred = subreq->len; - goto complete; - } - - if (transferred_or_error == 0) { - if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) { - subreq->error = -ENODATA; - goto failed; - } - } else { - __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags); - } - - __set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags); - set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags); - goto out; - -failed: - if (subreq->source == NETFS_READ_FROM_CACHE) { - netfs_stat(&netfs_n_rh_read_failed); - set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags); - } else { - netfs_stat(&netfs_n_rh_download_failed); - set_bit(NETFS_RREQ_FAILED, &rreq->flags); - rreq->error = subreq->error; - } - goto out; -} -EXPORT_SYMBOL(netfs_subreq_terminated); - -static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_subrequest *subreq, - loff_t i_size) -{ - struct netfs_io_request *rreq = subreq->rreq; - struct netfs_cache_resources *cres = &rreq->cache_resources; - - if (cres->ops) - return cres->ops->prepare_read(subreq, i_size); - if (subreq->start >= rreq->i_size) - return NETFS_FILL_WITH_ZEROES; - return NETFS_DOWNLOAD_FROM_SERVER; -} - -/* - * Work out what sort of subrequest the next one will be. - */ -static enum netfs_io_source -netfs_rreq_prepare_read(struct netfs_io_request *rreq, - struct netfs_io_subrequest *subreq, - struct iov_iter *io_iter) -{ - enum netfs_io_source source = NETFS_DOWNLOAD_FROM_SERVER; - struct netfs_inode *ictx = netfs_inode(rreq->inode); - size_t lsize; - - _enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size); - - if (rreq->origin != NETFS_DIO_READ) { - source = netfs_cache_prepare_read(subreq, rreq->i_size); - if (source == NETFS_INVALID_READ) - goto out; - } - - if (source == NETFS_DOWNLOAD_FROM_SERVER) { - /* Call out to the netfs to let it shrink the request to fit - * its own I/O sizes and boundaries. If it shinks it here, it - * will be called again to make simultaneous calls; if it wants - * to make serial calls, it can indicate a short read and then - * we will call it again. - */ - if (rreq->origin != NETFS_DIO_READ) { - if (subreq->start >= ictx->zero_point) { - source = NETFS_FILL_WITH_ZEROES; - goto set; - } - if (subreq->len > ictx->zero_point - subreq->start) - subreq->len = ictx->zero_point - subreq->start; - } - if (subreq->len > rreq->i_size - subreq->start) - subreq->len = rreq->i_size - subreq->start; - if (rreq->rsize && subreq->len > rreq->rsize) - subreq->len = rreq->rsize; - - if (rreq->netfs_ops->clamp_length && - !rreq->netfs_ops->clamp_length(subreq)) { - source = NETFS_INVALID_READ; - goto out; - } - - if (rreq->io_streams[0].sreq_max_segs) { - lsize = netfs_limit_iter(io_iter, 0, subreq->len, - rreq->io_streams[0].sreq_max_segs); - if (subreq->len > lsize) { - subreq->len = lsize; - trace_netfs_sreq(subreq, netfs_sreq_trace_limited); - } - } - } - -set: - if (subreq->len > rreq->len) - pr_warn("R=%08x[%u] SREQ>RREQ %zx > %llx\n", - rreq->debug_id, subreq->debug_index, - subreq->len, rreq->len); - - if (WARN_ON(subreq->len == 0)) { - source = NETFS_INVALID_READ; - goto out; - } - - subreq->source = source; - trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); - - subreq->io_iter = *io_iter; - iov_iter_truncate(&subreq->io_iter, subreq->len); - iov_iter_advance(io_iter, subreq->len); -out: - subreq->source = source; - trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); - return source; -} - -/* - * Slice off a piece of a read request and submit an I/O request for it. - */ -static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq, - struct iov_iter *io_iter) -{ - struct netfs_io_subrequest *subreq; - enum netfs_io_source source; - - subreq = netfs_alloc_subrequest(rreq); - if (!subreq) - return false; - - subreq->start = rreq->start + rreq->submitted; - subreq->len = io_iter->count; - - _debug("slice %llx,%zx,%llx", subreq->start, subreq->len, rreq->submitted); - list_add_tail(&subreq->rreq_link, &rreq->subrequests); - - /* Call out to the cache to find out what it can do with the remaining - * subset. It tells us in subreq->flags what it decided should be done - * and adjusts subreq->len down if the subset crosses a cache boundary. - * - * Then when we hand the subset, it can choose to take a subset of that - * (the starts must coincide), in which case, we go around the loop - * again and ask it to download the next piece. - */ - source = netfs_rreq_prepare_read(rreq, subreq, io_iter); - if (source == NETFS_INVALID_READ) - goto subreq_failed; - - atomic_inc(&rreq->nr_outstanding); - - rreq->submitted += subreq->len; - - trace_netfs_sreq(subreq, netfs_sreq_trace_submit); - switch (source) { - case NETFS_FILL_WITH_ZEROES: - netfs_fill_with_zeroes(rreq, subreq); - break; - case NETFS_DOWNLOAD_FROM_SERVER: - netfs_read_from_server(rreq, subreq); - break; - case NETFS_READ_FROM_CACHE: - netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_IGNORE); - break; - default: - BUG(); - } - - return true; - -subreq_failed: - rreq->error = subreq->error; - netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_failed); - return false; -} - -/* - * Begin the process of reading in a chunk of data, where that data may be - * stitched together from multiple sources, including multiple servers and the - * local cache. - */ -int netfs_begin_read(struct netfs_io_request *rreq, bool sync) -{ - struct iov_iter io_iter; - int ret; - - _enter("R=%x %llx-%llx", - rreq->debug_id, rreq->start, rreq->start + rreq->len - 1); - - if (rreq->len == 0) { - pr_err("Zero-sized read [R=%x]\n", rreq->debug_id); - return -EIO; - } - - if (rreq->origin == NETFS_DIO_READ) - inode_dio_begin(rreq->inode); - - // TODO: Use bounce buffer if requested - rreq->io_iter = rreq->iter; - - INIT_WORK(&rreq->work, netfs_rreq_work); - - /* Chop the read into slices according to what the cache and the netfs - * want and submit each one. - */ - netfs_get_request(rreq, netfs_rreq_trace_get_for_outstanding); - atomic_set(&rreq->nr_outstanding, 1); - io_iter = rreq->io_iter; - do { - _debug("submit %llx + %llx >= %llx", - rreq->start, rreq->submitted, rreq->i_size); - if (rreq->origin == NETFS_DIO_READ && - rreq->start + rreq->submitted >= rreq->i_size) - break; - if (!netfs_rreq_submit_slice(rreq, &io_iter)) - break; - if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) && - test_bit(NETFS_RREQ_NONBLOCK, &rreq->flags)) - break; - - } while (rreq->submitted < rreq->len); - - if (!rreq->submitted) { - netfs_put_request(rreq, false, netfs_rreq_trace_put_no_submit); - if (rreq->origin == NETFS_DIO_READ) - inode_dio_end(rreq->inode); - ret = 0; - goto out; - } - - if (sync) { - /* Keep nr_outstanding incremented so that the ref always - * belongs to us, and the service code isn't punted off to a - * random thread pool to process. Note that this might start - * further work, such as writing to the cache. - */ - wait_var_event(&rreq->nr_outstanding, - atomic_read(&rreq->nr_outstanding) == 1); - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_assess(rreq, false); - - trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip); - wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS, - TASK_UNINTERRUPTIBLE); - - ret = rreq->error; - if (ret == 0 && rreq->submitted < rreq->len && - rreq->origin != NETFS_DIO_READ) { - trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); - ret = -EIO; - } - } else { - /* If we decrement nr_outstanding to 0, the ref belongs to us. */ - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_assess(rreq, false); - ret = -EIOCBQUEUED; - } - -out: - return ret; -} +#endif diff --git a/fs/netfs/iterator.c b/fs/netfs/iterator.c index b781bbbf1d8d..52b7a337e5cd 100644 --- a/fs/netfs/iterator.c +++ b/fs/netfs/iterator.c @@ -188,9 +188,59 @@ static size_t netfs_limit_xarray(const struct iov_iter *iter, size_t start_offse return min(span, max_size); } +/* + * Select the span of a sheaf iterator we're going to use. Limit it by both + * maximum size and maximum number of segments. Returns the size of the span + * in bytes. + */ +static size_t netfs_limit_sheaf(const struct iov_iter *iter, size_t start_offset, + size_t max_size, size_t max_segs) +{ + const struct sheaf *sheaf = iter->sheaf; + unsigned int nsegs = 0; + unsigned int slot = iter->sheaf_slot; + size_t span = 0, n = iter->count; + + if (WARN_ON(!iov_iter_is_sheaf(iter)) || + WARN_ON(start_offset > n) || + n == 0) + return 0; + max_size = umin(max_size, n - start_offset); + + if (slot >= sheaf_nr_slots(sheaf)) { + sheaf = sheaf->next; + slot = 0; + } + + start_offset += iter->iov_offset; + do { + size_t flen = sheaf_folio_size(sheaf, slot); + + if (start_offset < flen) { + span += flen - start_offset; + nsegs++; + start_offset = 0; + } else { + start_offset -= flen; + } + if (span >= max_size || nsegs >= max_segs) + break; + + slot++; + if (slot >= sheaf_nr_slots(sheaf)) { + sheaf = sheaf->next; + slot = 0; + } + } while (sheaf); + + return umin(span, max_size); +} + size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset, size_t max_size, size_t max_segs) { + if (iov_iter_is_sheaf(iter)) + return netfs_limit_sheaf(iter, start_offset, max_size, max_segs); if (iov_iter_is_bvec(iter)) return netfs_limit_bvec(iter, start_offset, max_size, max_segs); if (iov_iter_is_xarray(iter)) diff --git a/fs/netfs/main.c b/fs/netfs/main.c index 5f0f438e5d21..b28e601a8386 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -54,21 +54,20 @@ static int netfs_requests_seq_show(struct seq_file *m, void *v) if (v == &netfs_io_requests) { seq_puts(m, - "REQUEST OR REF FL ERR OPS COVERAGE\n" - "======== == === == ==== === =========\n" + "REQUEST OR REF FL ERR COVERAGE\n" + "======== == === == ==== =========\n" ); return 0; } rreq = list_entry(v, struct netfs_io_request, proc_link); seq_printf(m, - "%08x %s %3d %2lx %4d %3d @%04llx %llx/%llx", + "%08x %s %3d %2lx %4d @%04llx %llx/%llx", rreq->debug_id, netfs_origins[rreq->origin], refcount_read(&rreq->ref), rreq->flags, rreq->error, - atomic_read(&rreq->nr_outstanding), rreq->start, rreq->submitted, rreq->len); seq_putc(m, '\n'); return 0; diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index d148a955fa55..a70d8d092401 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -40,7 +40,6 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, memset(rreq, 0, kmem_cache_size(cache)); rreq->start = start; rreq->len = len; - rreq->upper_len = len; rreq->origin = origin; rreq->netfs_ops = ctx->ops; rreq->mapping = mapping; diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c new file mode 100644 index 000000000000..c645fe5ba5b3 --- /dev/null +++ b/fs/netfs/read_collect.c @@ -0,0 +1,450 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Network filesystem read subrequest result collection, assessment and + * retrying. + * + * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include +#include "internal.h" + +/* + * Clear the unread part of an I/O request. + */ +static void netfs_clear_unread(struct netfs_io_subrequest *subreq) +{ + WARN_ON_ONCE(subreq->len - subreq->transferred != iov_iter_count(&subreq->io_iter)); + iov_iter_zero(iov_iter_count(&subreq->io_iter), &subreq->io_iter); +} + +/* + * Flush, mark and unlock a folio that's now completely read. If we want to + * cache the folio, we set the group to NETFS_FOLIO_COPY_TO_CACHE, mark it + * dirty and let writeback handle it. + */ +static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, + struct netfs_io_request *rreq, + struct folio *folio) +{ + struct netfs_folio *finfo; + + flush_dcache_folio(folio); + folio_mark_uptodate(folio); + + if (!test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags)) { + finfo = netfs_folio_info(folio); + if (finfo) { + trace_netfs_folio(folio, netfs_folio_trace_filled_gaps); + if (finfo->netfs_group) + folio_change_private(folio, finfo->netfs_group); + else + folio_detach_private(folio); + kfree(finfo); + } + + if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) { + if (!WARN_ON_ONCE(folio_get_private(folio) != NULL)) { + trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); + folio_attach_private(folio, NETFS_FOLIO_COPY_TO_CACHE); + filemap_dirty_folio(folio->mapping, folio); + } + } else { + trace_netfs_folio(folio, netfs_folio_trace_read_done); + } + } else { + // TODO: Use of PG_private_2 is deprecated. + if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) { + trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); + folio_start_private_2(folio); + } + } + + if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) { + if (folio->index == rreq->no_unlock_folio && + test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags)) + _debug("no unlock"); + else + folio_unlock(folio); + } +} + +/* + * Unlock any folios that are now completely read. Returns true if the + * subrequest is removed from the list. + */ +static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was_async) +{ + struct netfs_io_subrequest *prev, *next; + struct netfs_io_request *rreq = subreq->rreq; + struct sheaf *sheaf = subreq->curr_sheaf; + size_t avail, prev_donated, next_donated, fsize, part; + loff_t fpos, start; + loff_t fend; + int slot = subreq->curr_sheaf_slot; + + if (WARN(subreq->transferred > subreq->len, + "Subreq overread: R%x[%x] %zu > %zu", + rreq->debug_id, subreq->debug_index, + subreq->transferred, subreq->len)) + subreq->transferred = subreq->len; + +next_folio: + fsize = PAGE_SIZE << subreq->curr_folio_order; + fpos = round_down(subreq->start + subreq->consumed, fsize); + fend = fpos + fsize; + + if (WARN_ON_ONCE(sheaf_slot_folio(sheaf, slot)->index != fpos / PAGE_SIZE)) { + printk("R=%08x[%x] s=%llx-%llx ctl=%zx/%zx/%zx sl=%u\n", + rreq->debug_id, subreq->debug_index, + subreq->start, subreq->start + subreq->transferred, + subreq->consumed, subreq->transferred, subreq->len, + slot); + printk("folio: %llx-%llx ix=%llx\n", + fpos, fend - 1, folio_pos(sheaf_slot_folio(sheaf, slot))); + } + +donation_changed: + /* Try to consume the current folio if we've hit or passed the end of + * it. There's a possibility that this subreq doesn't start at the + * beginning of the folio, in which case we need to donate to/from the + * preceding subreq. + * + * We also need to include any potential donation back from the + * following subreq. + */ + prev_donated = READ_ONCE(subreq->prev_donated); + next_donated = READ_ONCE(subreq->next_donated); + + avail = subreq->transferred; + if (avail == subreq->len) + avail += next_donated; + start = subreq->start; + if (subreq->consumed == 0) { + start -= prev_donated; + avail += prev_donated; + } else { + start += subreq->consumed; + avail -= subreq->consumed; + } + part = umin(avail, fsize); + + trace_netfs_progress(subreq, start, avail, part); + + if (start + avail >= fend) { + if (fpos == start) { + /* Flush, unlock and mark for caching any folio we've just read. */ + subreq->consumed = fend - subreq->start; + netfs_unlock_read_folio(subreq, rreq, sheaf_slot_folio(sheaf, slot)); + if (subreq->consumed >= subreq->len) + goto remove_subreq; + } else if (fpos < start) { + size_t excess = fend - subreq->start; + + spin_lock(&rreq->lock); + /* If we complete first on a folio split with the + * preceding subreq, donate to that subreq - otherwise + * we get the responsibility. + */ + if (subreq->prev_donated != prev_donated) { + spin_unlock(&rreq->lock); + goto donation_changed; + } + + prev = list_prev_entry(subreq, rreq_link); + WRITE_ONCE(prev->next_donated, prev->next_donated + excess); + subreq->consumed = fend - subreq->start; + trace_netfs_donate(rreq, subreq, prev, excess, + netfs_trace_donate_tail_to_prev); + + if (subreq->consumed >= subreq->len) + goto remove_subreq_locked; + spin_unlock(&rreq->lock); + } else { + pr_err("fpos > start\n"); + goto bad; + } + + /* Advance the rolling buffer to the next folio. */ + slot++; + if (slot >= sheaf_nr_slots(sheaf)) { + slot = 0; + sheaf = sheaf->next; + subreq->curr_sheaf = sheaf; + } + subreq->curr_sheaf_slot = slot; + if (sheaf && sheaf->slots[slot]) + subreq->curr_folio_order = sheaf->orders[slot]; + cond_resched(); + goto next_folio; + } + + /* Deal with partial progress. */ + if (subreq->transferred < subreq->len) + return false; + + /* Donate the remaining downloaded data to one of the neighbouring + * subrequests. Note that we may race with them doing the same thing. + */ + spin_lock(&rreq->lock); + + if (subreq->prev_donated != prev_donated || + subreq->next_donated != next_donated) { + spin_unlock(&rreq->lock); + cond_resched(); + goto donation_changed; + } + + /* Deal with the trickiest case: that this subreq is in the middle of a + * folio, not touching either edge, but finishes first. In such a + * case, we donate to the previous subreq, if there is one, so that the + * donation is only handled when that completes - and remove this + * subreq from the list. + * + * If the previous subreq finished first, we will have acquired their + * donation and should be able to unlock folios and/or donate nextwards. + */ + if (!subreq->consumed) { + if (!prev_donated && !next_donated && + !list_is_first(&subreq->rreq_link, &rreq->subrequests)) { + prev = list_prev_entry(subreq, rreq_link); + WRITE_ONCE(prev->next_donated, prev->next_donated + subreq->len); + trace_netfs_donate(rreq, subreq, prev, prev->next_donated + subreq->len, + netfs_trace_donate_to_prev); + goto remove_subreq_locked; + } + } + + if (!next_donated) { + size_t excess = subreq->len - subreq->consumed; + + if (!subreq->consumed) + excess += prev_donated; + + if (list_is_last(&subreq->rreq_link, &rreq->subrequests)) { + rreq->prev_donated = excess; + trace_netfs_donate(rreq, subreq, NULL, excess, + netfs_trace_donate_to_deferred_next); + } else { + next = list_next_entry(subreq, rreq_link); + WRITE_ONCE(next->prev_donated, excess); + trace_netfs_donate(rreq, subreq, next, excess, + netfs_trace_donate_to_next); + } + goto remove_subreq_locked; + } + + spin_unlock(&rreq->lock); + +bad: + /* Errr... prev and next both donated to us, but insufficient to finish + * the folio. + */ + printk("R=%08x[%x] s=%llx-%llx %zx/%zx/%zx\n", + rreq->debug_id, subreq->debug_index, + subreq->start, subreq->start + subreq->transferred, + subreq->consumed, subreq->transferred, subreq->len); + printk("folio: %llx-%llx\n", fpos, fend - 1); + printk("donated: prev=%zx next=%zx\n", prev_donated, next_donated); + printk("s=%llx av=%zx part=%zx\n", start, avail, part); + BUG(); + +remove_subreq: + spin_lock(&rreq->lock); +remove_subreq_locked: + subreq->consumed = subreq->len; + list_del(&subreq->rreq_link); + spin_unlock(&rreq->lock); + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_consumed); + return true; +} + +/* + * Release those waiting. + */ +static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async) +{ + trace_netfs_rreq(rreq, netfs_rreq_trace_done); + netfs_clear_subrequests(rreq, was_async); +} + +/* + * Determine how much we can admit to having read from a DIO read. + */ +static void netfs_rreq_assess_dio(struct netfs_io_request *rreq) +{ + struct netfs_io_subrequest *subreq; + unsigned int i; + size_t transferred = 0; + + for (i = 0; i < rreq->direct_bv_count; i++) { + flush_dcache_page(rreq->direct_bv[i].bv_page); + // TODO: cifs marks pages in the destination buffer + // dirty under some circumstances after a read. Do we + // need to do that too? + set_page_dirty(rreq->direct_bv[i].bv_page); + } + + list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { + if (subreq->error || subreq->transferred == 0) + break; + transferred += subreq->transferred; + if (subreq->transferred < subreq->len) + break; + } + + for (i = 0; i < rreq->direct_bv_count; i++) + flush_dcache_page(rreq->direct_bv[i].bv_page); + + rreq->transferred = transferred; + + if (rreq->iocb) { + rreq->iocb->ki_pos += transferred; + if (rreq->iocb->ki_complete) + rreq->iocb->ki_complete( + rreq->iocb, rreq->error ? rreq->error : transferred); + } + if (rreq->netfs_ops->done) + rreq->netfs_ops->done(rreq); + inode_dio_end(rreq->inode); +} + +/* + * Assess the state of a read request and decide what to do next. + * + * Note that we could be in an ordinary kernel thread, on a workqueue or in + * softirq context at this point. We inherit a ref from the caller. + */ +static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async) +{ + trace_netfs_rreq(rreq, netfs_rreq_trace_assess); + + //netfs_rreq_is_still_valid(rreq); + + if (rreq->origin == NETFS_DIO_READ) + netfs_rreq_assess_dio(rreq); + task_io_account_read(rreq->transferred); + + trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip); + clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags); + wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS); + + netfs_rreq_completed(rreq, was_async); +} + +static void netfs_rreq_work(struct work_struct *work) +{ + struct netfs_io_request *rreq = + container_of(work, struct netfs_io_request, work); + netfs_rreq_assess(rreq, false); +} + +/* + * Handle the completion of all outstanding I/O operations on a read request. + * We inherit a ref from the caller. + */ +static void netfs_rreq_terminated(struct netfs_io_request *rreq, bool was_async) +{ + if (test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags) && + was_async) { + INIT_WORK(&rreq->work, netfs_rreq_work); + if (!queue_work(system_unbound_wq, &rreq->work)) + BUG(); + } else { + netfs_rreq_assess(rreq, was_async); + } +} + +/** + * netfs_read_subreq_progress - Note progress of a read operation. + * @subreq: The read request that has terminated. + * @error: Completion code or -EAGAIN if just a progress update. + * @was_async: The termination was asynchronous + * + * This tells the read side of netfs lib that a contributory I/O operation has + * made progress, one way or another, and that it may be possible to unlock + * some folios. + * + * The caller indicates in @error the state of the operation, supplying 0 to + * indicate successful completion of the operation, -EINPROGRESS to indicate + * that the operation is still ongoing or some other negative error code on + * failure. The helper will look after reissuing I/O operations as appropriate + * and writing downloaded data to the cache. + * + * The filesystem should update subreq->transferred to track the amount of data + * copied into the output buffer. + * + * If @was_async is true, the caller might be running in softirq or interrupt + * context and we can't sleep. + */ +void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq, + int error, bool was_async) +{ + struct netfs_io_request *rreq = subreq->rreq; + + /* If the read completed validly short, then we can clear the tail + * before going on to unlock the folios. + */ + if (error == 0 && subreq->transferred < subreq->len && + test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags)) { + netfs_clear_unread(subreq); + subreq->transferred = subreq->len; + } + + if (subreq->transferred > subreq->consumed) { + if (rreq->origin != NETFS_DIO_READ) + netfs_consume_read_data(subreq, was_async); + __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags); + } + + /* If we had progress, but not completion, then we're done for now. */ + if (error == -EINPROGRESS) + return; + + switch (subreq->source) { + case NETFS_READ_FROM_CACHE: + netfs_stat(&netfs_n_rh_read_done); + break; + case NETFS_DOWNLOAD_FROM_SERVER: + netfs_stat(&netfs_n_rh_download_done); + break; + default: + break; + } + + if (subreq->transferred < subreq->len) { + __set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags); + set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags); + if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) + error = -ENODATA; + } + + subreq->error = error; + if (error < 0) { + trace_netfs_failure(rreq, subreq, error, netfs_fail_read); + if (subreq->source == NETFS_READ_FROM_CACHE) { + netfs_stat(&netfs_n_rh_read_failed); + set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags); + } else { + netfs_stat(&netfs_n_rh_download_failed); + set_bit(NETFS_RREQ_FAILED, &rreq->flags); + rreq->error = subreq->error; + } + } else { + __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags); + } + + rreq->transferred += subreq->transferred; + trace_netfs_sreq(subreq, netfs_sreq_trace_terminated); + + if (list_empty(&rreq->subrequests)) + netfs_rreq_terminated(rreq, was_async); + + netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated); +} +EXPORT_SYMBOL(netfs_read_subreq_progress); diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index fb92dd8160f3..413199617476 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -158,10 +158,6 @@ static void netfs_prepare_write(struct netfs_io_request *wreq, _enter("R=%x[%x]", wreq->debug_id, subreq->debug_index); - trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index, - refcount_read(&subreq->ref), - netfs_sreq_trace_new); - trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); stream->sreq_max_len = UINT_MAX; diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c index ddc1ee031955..6d7d04c9eff6 100644 --- a/fs/nfs/fscache.c +++ b/fs/nfs/fscache.c @@ -286,15 +286,7 @@ static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sre return netfs; } -static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq) -{ - size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize; - - sreq->len = min(sreq->len, rsize); - return true; -} - -static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq) +static ssize_t nfs_netfs_issue_read(struct netfs_io_subrequest *sreq) { struct nfs_netfs_io_data *netfs; struct nfs_pageio_descriptor pgio; @@ -302,17 +294,26 @@ static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq) struct nfs_open_context *ctx = sreq->rreq->netfs_priv; struct page *page; unsigned long idx; + pgoff_t start, last; + ssize_t len; int err; - pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT; - pgoff_t last = ((sreq->start + sreq->len - - sreq->transferred - 1) >> PAGE_SHIFT); + + err = netfs_prepare_read_iterator(sreq, NFS_SB(sreq->rreq->inode->i_sb)->rsize, 0); + if (err < 0) + return err; + + len = sreq->len; + start = (sreq->start + sreq->transferred) >> PAGE_SHIFT; + last = ((sreq->start + len - sreq->transferred - 1) >> PAGE_SHIFT); nfs_pageio_init_read(&pgio, inode, false, &nfs_async_read_completion_ops); netfs = nfs_netfs_alloc(sreq); - if (!netfs) - return netfs_subreq_terminated(sreq, -ENOMEM, false); + if (!netfs) { + netfs_read_subreq_progress(sreq, -ENOMEM, false); + return -ENOMEM; + } pgio.pg_netfs = netfs; /* used in completion */ @@ -327,6 +328,7 @@ static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq) out: nfs_pageio_complete_read(&pgio); nfs_netfs_put(netfs); + return len; } void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) @@ -377,5 +379,4 @@ const struct netfs_request_ops nfs_netfs_ops = { .init_request = nfs_netfs_init_request, .free_request = nfs_netfs_free_request, .issue_read = nfs_netfs_issue_read, - .clamp_length = nfs_netfs_clamp_length }; diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h index fbed0027996f..20c1d73085cd 100644 --- a/fs/nfs/fscache.h +++ b/fs/nfs/fscache.h @@ -60,8 +60,6 @@ static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs) static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs) { - ssize_t final_len; - /* Only the last RPC completion should call netfs_subreq_terminated() */ if (!refcount_dec_and_test(&netfs->refcount)) return; @@ -74,8 +72,9 @@ static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs) * Correct the final length here to be no larger than the netfs subrequest * length, and thus avoid netfs's "Subreq overread" warning message. */ - final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred)); - netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false); + netfs->sreq->transferred = min_t(s64, netfs->sreq->len, + atomic64_read(&netfs->transferred)); + netfs_read_subreq_progress(netfs->sreq, netfs->error, false); kfree(netfs); } static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 595c4b673707..ff7f95395239 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -1309,10 +1309,8 @@ cifs_readv_callback(struct mid_q_entry *mid) if (rdata->result == 0 || rdata->result == -EAGAIN) iov_iter_advance(&rdata->subreq.io_iter, rdata->got_bytes); rdata->credits.value = 0; - netfs_subreq_terminated(&rdata->subreq, - (rdata->result == 0 || rdata->result == -EAGAIN) ? - rdata->got_bytes : rdata->result, - false); + rdata->subreq.transferred += rdata->got_bytes; + netfs_read_subreq_progress(&rdata->subreq, rdata->result, false); release_mid(mid); add_credits(server, &credits, 0); } diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 4732c63f7531..f3be9444465a 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include "cifsfs.h" #include "cifspdu.h" @@ -125,22 +126,21 @@ static void cifs_issue_write(struct netfs_io_subrequest *subreq) } /* - * Split the read up according to how many credits we can get for each piece. - * It's okay to sleep here if we need to wait for more credit to become - * available. - * - * We also choose the server and allocate an operation ID to be cleaned up - * later. + * Issue a read operation on behalf of the netfs helper functions. We're asked + * to make a read of a certain size at a point in the file. We are permitted + * to only read a portion of that, but as long as we read something, the netfs + * helper will call us again so that we can issue another read. */ -static bool cifs_clamp_length(struct netfs_io_subrequest *subreq) +static ssize_t cifs_issue_read(struct netfs_io_subrequest *subreq) { struct netfs_io_request *rreq = subreq->rreq; - struct netfs_io_stream *stream = &rreq->io_streams[subreq->stream_nr]; struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); struct TCP_Server_Info *server = req->server; struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb); - int rc; + unsigned int max_segs = 0; + size_t rsize, len; + int rc = 0; rdata->xid = get_xid(); rdata->have_xid = true; @@ -153,52 +153,48 @@ static bool cifs_clamp_length(struct netfs_io_subrequest *subreq) rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->rsize, - &stream->sreq_max_len, &rdata->credits); - if (rc) { - subreq->error = rc; - return false; - } + &rsize, &rdata->credits); + if (rc) + goto failed; - subreq->len = umin(subreq->len, stream->sreq_max_len); #ifdef CONFIG_CIFS_SMB_DIRECT if (server->smbd_conn) - stream->sreq_max_segs = server->smbd_conn->max_frmr_depth; + max_segs = server->smbd_conn->max_frmr_depth; #endif - return true; -} -/* - * Issue a read operation on behalf of the netfs helper functions. We're asked - * to make a read of a certain size at a point in the file. We are permitted - * to only read a portion of that, but as long as we read something, the netfs - * helper will call us again so that we can issue another read. - */ -static void cifs_req_issue_read(struct netfs_io_subrequest *subreq) -{ - struct netfs_io_request *rreq = subreq->rreq; - struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); - struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); - struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb); - int rc = 0; + len = netfs_prepare_read_iterator(subreq, rsize, max_segs); + if (len < 0) { + rc = len; + goto failed; + } cifs_dbg(FYI, "%s: op=%08x[%x] mapping=%p len=%zu/%zu\n", __func__, rreq->debug_id, subreq->debug_index, rreq->mapping, - subreq->transferred, subreq->len); + subreq->transferred, len); + + rc = adjust_credits(server, &rdata->credits, len); + if (rc) + goto failed; if (req->cfile->invalidHandle) { do { rc = cifs_reopen_file(req->cfile, true); } while (rc == -EAGAIN); if (rc) - goto out; + goto failed; } __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); + trace_netfs_sreq(subreq, netfs_sreq_trace_submit); rc = rdata->server->ops->async_readv(rdata); -out: if (rc) - netfs_subreq_terminated(subreq, rc, false); + goto failed; + return len; + +failed: + netfs_read_subreq_progress(subreq, rc, false); + return rc; } /* @@ -326,8 +322,7 @@ const struct netfs_request_ops cifs_req_ops = { .free_request = cifs_free_request, .free_subrequest = cifs_free_subrequest, .expand_readahead = cifs_expand_readahead, - .clamp_length = cifs_clamp_length, - .issue_read = cifs_req_issue_read, + .issue_read = cifs_issue_read, .done = cifs_rreq_done, .begin_writeback = cifs_begin_writeback, .prepare_write = cifs_prepare_write, diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 2ae2dbb6202b..14988281cce6 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -4489,9 +4489,7 @@ static void smb2_readv_worker(struct work_struct *work) struct cifs_io_subrequest *rdata = container_of(work, struct cifs_io_subrequest, subreq.work); - netfs_subreq_terminated(&rdata->subreq, - (rdata->result == 0 || rdata->result == -EAGAIN) ? - rdata->got_bytes : rdata->result, true); + netfs_read_subreq_progress(&rdata->subreq, rdata->result, false); } static void @@ -4538,6 +4536,7 @@ smb2_readv_callback(struct mid_q_entry *mid) break; case MID_REQUEST_SUBMITTED: case MID_RETRY_NEEDED: + __set_bit(NETFS_SREQ_NEED_RETRY, &rdata->subreq.flags); rdata->result = -EAGAIN; if (server->sign && rdata->got_bytes) /* reset bytes number since we can not check a sign */ @@ -4588,6 +4587,8 @@ smb2_readv_callback(struct mid_q_entry *mid) rdata->result = 0; } rdata->credits.value = 0; + rdata->subreq.transferred += rdata->got_bytes; + trace_netfs_sreq(&rdata->subreq, netfs_sreq_trace_io_progress); INIT_WORK(&rdata->subreq.work, smb2_readv_worker); queue_work(cifsiod_wq, &rdata->subreq.work); release_mid(mid); @@ -4838,6 +4839,7 @@ smb2_writev_callback(struct mid_q_entry *mid) wdata->subreq.start, wdata->subreq.len); wdata->credits.value = 0; + trace_netfs_sreq(&wdata->subreq, netfs_sreq_trace_io_progress); cifs_write_subrequest_terminated(wdata, result ?: written, true); release_mid(mid); add_credits(server, &credits, 0); diff --git a/include/linux/netfs.h b/include/linux/netfs.h index b880687bb932..6987c2c02074 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -183,12 +183,18 @@ struct netfs_io_subrequest { unsigned long long start; /* Where to start the I/O */ size_t len; /* Size of the I/O */ size_t transferred; /* Amount of data transferred */ + size_t consumed; /* Amount of read data consumed */ + unsigned int prev_donated; /* Amount of data donated from previous subreq */ + unsigned int next_donated; /* Amount of data donated from next subreq */ refcount_t ref; short error; /* 0 or error that occurred */ unsigned short debug_index; /* Index in list (for debugging output) */ unsigned int nr_segs; /* Number of segs in io_iter */ enum netfs_io_source source; /* Where to read from/write to */ unsigned char stream_nr; /* I/O stream this belongs to */ + unsigned char curr_sheaf_slot; /* Folio currently being read */ + unsigned char curr_folio_order; /* Order of folio */ + struct sheaf *curr_sheaf; /* Sheaf in which current folio resides */ unsigned long flags; #define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */ #define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */ @@ -229,6 +235,7 @@ struct netfs_io_request { struct address_space *mapping; /* The mapping being accessed */ struct kiocb *iocb; /* AIO completion vector */ struct netfs_cache_resources cache_resources; + struct readahead_control *ractl; /* Readahead descriptor */ struct list_head proc_link; /* Link in netfs_iorequests */ struct list_head subrequests; /* Contributory I/O operations */ struct netfs_io_stream io_streams[2]; /* Streams of parallel I/O operations */ @@ -248,9 +255,6 @@ struct netfs_io_request { atomic_t subreq_counter; /* Next subreq->debug_index */ unsigned int nr_group_rel; /* Number of refs to release on ->group */ spinlock_t lock; /* Lock for queuing subreqs */ - atomic_t nr_outstanding; /* Number of ops in progress */ - atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */ - size_t upper_len; /* Length can be extended to here */ unsigned long long submitted; /* Amount submitted for I/O so far */ unsigned long long len; /* Length of the request */ size_t transferred; /* Amount to be indicated as transferred */ @@ -265,6 +269,7 @@ struct netfs_io_request { unsigned long long collected_to; /* Point we've collected to */ unsigned long long cleaned_to; /* Position we've cleaned folios to */ pgoff_t no_unlock_folio; /* Don't unlock this folio after read */ + unsigned int prev_donated; /* Fallback for subreq->prev_donated */ refcount_t ref; unsigned long flags; #define NETFS_RREQ_INCOMPLETE_IO 0 /* Some ioreqs terminated short or with error */ @@ -298,8 +303,7 @@ struct netfs_request_ops { /* Read request handling */ void (*expand_readahead)(struct netfs_io_request *rreq); - bool (*clamp_length)(struct netfs_io_subrequest *subreq); - void (*issue_read)(struct netfs_io_subrequest *subreq); + ssize_t (*issue_read)(struct netfs_io_subrequest *subreq); bool (*is_still_valid)(struct netfs_io_request *rreq); int (*check_write_begin)(struct file *file, loff_t pos, unsigned len, struct folio **foliop, void **_fsdata); @@ -428,7 +432,10 @@ bool netfs_release_folio(struct folio *folio, gfp_t gfp); vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group); /* (Sub)request management API. */ -void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool); +ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq, size_t rsize, + unsigned int max_segs); +void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq, + int error, bool was_async); void netfs_get_subrequest(struct netfs_io_subrequest *subreq, enum netfs_sreq_ref_trace what); void netfs_put_subrequest(struct netfs_io_subrequest *subreq, diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h index 64238a64ae5f..6d3403880e0b 100644 --- a/include/trace/events/netfs.h +++ b/include/trace/events/netfs.h @@ -68,10 +68,14 @@ E_(NETFS_INVALID_WRITE, "INVL") #define netfs_sreq_traces \ + EM(netfs_sreq_trace_added, "ADD ") \ EM(netfs_sreq_trace_discard, "DSCRD") \ + EM(netfs_sreq_trace_donate_to_prev, "DON-P") \ + EM(netfs_sreq_trace_donate_to_next, "DON-N") \ EM(netfs_sreq_trace_download_instead, "RDOWN") \ EM(netfs_sreq_trace_fail, "FAIL ") \ EM(netfs_sreq_trace_free, "FREE ") \ + EM(netfs_sreq_trace_io_progress, "IO ") \ EM(netfs_sreq_trace_limited, "LIMIT") \ EM(netfs_sreq_trace_prepare, "PREP ") \ EM(netfs_sreq_trace_prep_failed, "PRPFL") \ @@ -117,7 +121,7 @@ EM(netfs_sreq_trace_new, "NEW ") \ EM(netfs_sreq_trace_put_cancel, "PUT CANCEL ") \ EM(netfs_sreq_trace_put_clear, "PUT CLEAR ") \ - EM(netfs_sreq_trace_put_discard, "PUT DISCARD") \ + EM(netfs_sreq_trace_put_consumed, "PUT CONSUME") \ EM(netfs_sreq_trace_put_done, "PUT DONE ") \ EM(netfs_sreq_trace_put_failed, "PUT FAILED ") \ EM(netfs_sreq_trace_put_merged, "PUT MERGED ") \ @@ -151,7 +155,10 @@ EM(netfs_folio_trace_mkwrite, "mkwrite") \ EM(netfs_folio_trace_mkwrite_plus, "mkwrite+") \ EM(netfs_folio_trace_not_under_wback, "!wback") \ + EM(netfs_folio_trace_read, "read") \ + EM(netfs_folio_trace_read_done, "read-done") \ EM(netfs_folio_trace_read_gaps, "read-gaps") \ + EM(netfs_folio_trace_read_put, "read-put") \ EM(netfs_folio_trace_redirtied, "redirtied") \ EM(netfs_folio_trace_store, "store") \ EM(netfs_folio_trace_store_copy, "store-copy") \ @@ -164,6 +171,12 @@ EM(netfs_contig_trace_jump, "-->JUMP-->") \ E_(netfs_contig_trace_unlock, "Unlock") +#define netfs_donate_traces \ + EM(netfs_trace_donate_tail_to_prev, "tail-to-prev") \ + EM(netfs_trace_donate_to_prev, "to-prev") \ + EM(netfs_trace_donate_to_next, "to-next") \ + E_(netfs_trace_donate_to_deferred_next, "defer-next") + #ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY #define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY @@ -181,6 +194,7 @@ enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte); enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte); enum netfs_folio_trace { netfs_folio_traces } __mode(byte); enum netfs_collect_contig_trace { netfs_collect_contig_traces } __mode(byte); +enum netfs_donate_trace { netfs_donate_traces } __mode(byte); #endif @@ -203,6 +217,7 @@ netfs_rreq_ref_traces; netfs_sreq_ref_traces; netfs_folio_traces; netfs_collect_contig_traces; +netfs_donate_traces; /* * Now redefine the EM() and E_() macros to map the enums to the strings that @@ -651,6 +666,71 @@ TRACE_EVENT(netfs_collect_stream, __entry->collected_to, __entry->front) ); +TRACE_EVENT(netfs_progress, + TP_PROTO(const struct netfs_io_subrequest *subreq, + unsigned long long start, size_t avail, size_t part), + + TP_ARGS(subreq, start, avail, part), + + TP_STRUCT__entry( + __field(unsigned int, rreq) + __field(unsigned int, subreq) + __field(unsigned int, consumed) + __field(unsigned int, transferred) + __field(unsigned long long, f_start) + __field(unsigned int, f_avail) + __field(unsigned int, f_part) + __field(unsigned char, slot) + ), + + TP_fast_assign( + __entry->rreq = subreq->rreq->debug_id; + __entry->subreq = subreq->debug_index; + __entry->consumed = subreq->consumed; + __entry->transferred = subreq->transferred; + __entry->f_start = start; + __entry->f_avail = avail; + __entry->f_part = part; + __entry->slot = subreq->curr_sheaf_slot; + ), + + TP_printk("R=%08x[%02x] s=%llx ct=%x/%x pa=%x/%x sl=%x", + __entry->rreq, __entry->subreq, __entry->f_start, + __entry->consumed, __entry->transferred, + __entry->f_part, __entry->f_avail, __entry->slot) + ); + +TRACE_EVENT(netfs_donate, + TP_PROTO(const struct netfs_io_request *rreq, + const struct netfs_io_subrequest *from, + const struct netfs_io_subrequest *to, + size_t amount, + enum netfs_donate_trace trace), + + TP_ARGS(rreq, from, to, amount, trace), + + TP_STRUCT__entry( + __field(unsigned int, rreq) + __field(unsigned int, from) + __field(unsigned int, to) + __field(unsigned int, amount) + __field(enum netfs_donate_trace, trace) + ), + + TP_fast_assign( + __entry->rreq = rreq->debug_id; + __entry->from = from->debug_index; + __entry->to = to ? to->debug_index : -1; + __entry->amount = amount; + __entry->trace = trace; + ), + + TP_printk("R=%08x[%02x] -> [%02x] %s am=%x", + __entry->rreq, __entry->from, __entry->to, + __print_symbolic(__entry->trace, netfs_donate_traces), + __entry->amount) + ); + #undef EM #undef E_ #endif /* _TRACE_NETFS_H */