From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12DB8C433EF for ; Thu, 10 Mar 2022 16:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243097AbiCJQS5 (ORCPT ); Thu, 10 Mar 2022 11:18:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242400AbiCJQSO (ORCPT ); Thu, 10 Mar 2022 11:18:14 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 77F0D190C16 for ; Thu, 10 Mar 2022 08:17:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646929031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IdTqqPUoe91n3yafXJ9ND30dPaE+5rnymp9Pdr4PMTA=; b=a/1FFF6i6cLFAbJD8UmjgdUktE6DK+3L3/vEZElgyjfLVkRUX5BcLY8yV56gwC0o/REVgE NVsRAjjAoVM4kHFG6RTV6c+eOJC/GIQEaWjMozAVYuUfkUZpaifg2QPFlRD2ibaCWoK5y/ zvjpUGCwJHvpJTdnsxLWFJfVy0aOVoo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-220-c-lOPo6qMCmOhixK_YuXBw-1; Thu, 10 Mar 2022 11:17:09 -0500 X-MC-Unique: c-lOPo6qMCmOhixK_YuXBw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1AFA41091DA1; Thu, 10 Mar 2022 16:17:07 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 706947AC6B; Thu, 10 Mar 2022 16:16:59 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH v3 08/20] netfs: Trace refcounting on the netfs_io_subrequest struct From: David Howells To: linux-cachefs@redhat.com Cc: Jeff Layton , dhowells@redhat.com, Anna Schumaker , Steve French , Dominique Martinet , Jeff Layton , David Wysochanski , Ilya Dryomov , Jeffle Xu , Linus Torvalds , linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 10 Mar 2022 16:16:58 +0000 Message-ID: <164692901860.2099075.4845820886851239935.stgit@warthog.procyon.org.uk> In-Reply-To: <164692883658.2099075.5745824552116419504.stgit@warthog.procyon.org.uk> References: <164692883658.2099075.5745824552116419504.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.4 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add refcount tracing for the netfs_io_subrequest structure. Changes ======= ver #3) - Switch 'W=' to 'R=' in the traceline to match other request debug IDs. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164622998584.3564931.5052255990645723639.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678202603.1200972.14726007419792315578.stgit@warthog.procyon.org.uk/ # v2 --- fs/netfs/internal.h | 2 -- fs/netfs/objects.c | 32 +++++++++++++++++++++++--------- fs/netfs/read_helper.c | 20 +++++++++++--------- include/linux/netfs.h | 8 +++++++- include/trace/events/netfs.h | 40 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 81 insertions(+), 21 deletions(-) diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index 89b02357500d..a0b7d1bf9f3d 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -25,8 +25,6 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async); void netfs_put_request(struct netfs_io_request *rreq, bool was_async, enum netfs_rreq_ref_trace what); struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq); -void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async); -void netfs_get_subrequest(struct netfs_io_subrequest *subreq); static inline void netfs_see_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 4e29c3bb6e5a..39097893e847 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -53,7 +53,8 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async) subreq = list_first_entry(&rreq->subrequests, struct netfs_io_subrequest, rreq_link); list_del(&subreq->rreq_link); - netfs_put_subrequest(subreq, was_async); + netfs_put_subrequest(subreq, was_async, + netfs_sreq_trace_put_clear); } } @@ -101,7 +102,7 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL); if (subreq) { INIT_LIST_HEAD(&subreq->rreq_link); - refcount_set(&subreq->usage, 2); + refcount_set(&subreq->ref, 2); subreq->rreq = rreq; netfs_get_request(rreq, netfs_rreq_trace_get_subreq); netfs_stat(&netfs_n_rh_sreq); @@ -110,13 +111,18 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq return subreq; } -void netfs_get_subrequest(struct netfs_io_subrequest *subreq) +void netfs_get_subrequest(struct netfs_io_subrequest *subreq, + enum netfs_sreq_ref_trace what) { - refcount_inc(&subreq->usage); + int r; + + __refcount_inc(&subreq->ref, &r); + trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, + what); } -static void __netfs_put_subrequest(struct netfs_io_subrequest *subreq, - bool was_async) +static void netfs_free_subrequest(struct netfs_io_subrequest *subreq, + bool was_async) { struct netfs_io_request *rreq = subreq->rreq; @@ -126,8 +132,16 @@ static void __netfs_put_subrequest(struct netfs_io_subrequest *subreq, netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq); } -void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async) +void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async, + enum netfs_sreq_ref_trace what) { - if (refcount_dec_and_test(&subreq->usage)) - __netfs_put_subrequest(subreq, was_async); + unsigned int debug_index = subreq->debug_index; + unsigned int debug_id = subreq->rreq->debug_id; + bool dead; + int r; + + dead = __refcount_dec_and_test(&subreq->ref, &r); + trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what); + if (dead) + netfs_free_subrequest(subreq, was_async); } diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c index 620c3be5ec0a..8f277da487b6 100644 --- a/fs/netfs/read_helper.c +++ b/fs/netfs/read_helper.c @@ -167,7 +167,7 @@ static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error, if (atomic_dec_and_test(&rreq->nr_copy_ops)) netfs_rreq_unmark_after_write(rreq, was_async); - netfs_put_subrequest(subreq, was_async); + netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated); } /* @@ -191,7 +191,8 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq) list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) { if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) { list_del_init(&subreq->rreq_link); - netfs_put_subrequest(subreq, false); + netfs_put_subrequest(subreq, false, + netfs_sreq_trace_put_no_copy); } } @@ -203,7 +204,8 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq) break; subreq->len += next->len; list_del_init(&next->rreq_link); - netfs_put_subrequest(next, false); + netfs_put_subrequest(next, false, + netfs_sreq_trace_put_merged); } ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len, @@ -219,7 +221,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq) atomic_inc(&rreq->nr_copy_ops); netfs_stat(&netfs_n_rh_write); - netfs_get_subrequest(subreq); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache); trace_netfs_sreq(subreq, netfs_sreq_trace_write); cres->ops->write(cres, subreq->start, &iter, netfs_rreq_copy_terminated, subreq); @@ -342,7 +344,7 @@ static void netfs_rreq_short_read(struct netfs_io_request *rreq, netfs_stat(&netfs_n_rh_short_read); trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short); - netfs_get_subrequest(subreq); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_short_read); atomic_inc(&rreq->nr_outstanding); if (subreq->source == NETFS_READ_FROM_CACHE) netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR); @@ -376,7 +378,7 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq) subreq->error = 0; netfs_stat(&netfs_n_rh_download_instead); trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead); - netfs_get_subrequest(subreq); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); atomic_inc(&rreq->nr_outstanding); netfs_read_from_server(rreq, subreq); } else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) { @@ -538,7 +540,7 @@ void netfs_subreq_terminated(struct netfs_io_subrequest *subreq, else if (u == 1) wake_up_var(&rreq->nr_outstanding); - netfs_put_subrequest(subreq, was_async); + netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated); return; incomplete: @@ -683,7 +685,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq, subreq_failed: rreq->error = subreq->error; - netfs_put_subrequest(subreq, false); + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_failed); return false; } @@ -1030,13 +1032,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping, */ ractl._nr_pages = folio_nr_pages(folio); netfs_rreq_expand(rreq, &ractl); + netfs_get_request(rreq, netfs_rreq_trace_get_hold); /* We hold the folio locks, so we can drop the references */ folio_get(folio); while (readahead_folio(&ractl)) ; - netfs_get_request(rreq, netfs_rreq_trace_get_hold); atomic_set(&rreq->nr_outstanding, 1); do { if (!netfs_rreq_submit_slice(rreq, &debug_index)) diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 541aebe828f3..c702bd8ea8da 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -18,6 +18,8 @@ #include #include +enum netfs_sreq_ref_trace; + /* * Overload PG_private_2 to give us PG_fscache - this is used to indicate that * a page is currently backed by a local disk cache @@ -136,7 +138,7 @@ struct netfs_io_subrequest { loff_t start; /* Where to start the I/O */ size_t len; /* Size of the I/O */ size_t transferred; /* Amount of data transferred */ - refcount_t usage; + refcount_t ref; short error; /* 0 or error that occurred */ unsigned short debug_index; /* Index in list (for debugging output) */ enum netfs_io_source source; /* Where to read from/write to */ @@ -268,6 +270,10 @@ extern int netfs_write_begin(struct file *, struct address_space *, void *); extern void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool); +extern void netfs_get_subrequest(struct netfs_io_subrequest *subreq, + enum netfs_sreq_ref_trace what); +extern void netfs_put_subrequest(struct netfs_io_subrequest *subreq, + bool was_async, enum netfs_sreq_ref_trace what); extern void netfs_stats_show(struct seq_file *); #endif /* _LINUX_NETFS_H */ diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h index e35a5ce52eb5..dcea5e888fd0 100644 --- a/include/trace/events/netfs.h +++ b/include/trace/events/netfs.h @@ -64,6 +64,17 @@ EM(netfs_rreq_trace_put_subreq, "PUT SUBREQ ") \ E_(netfs_rreq_trace_new, "NEW ") +#define netfs_sreq_ref_traces \ + EM(netfs_sreq_trace_get_copy_to_cache, "GET COPY2C ") \ + EM(netfs_sreq_trace_get_resubmit, "GET RESUBMIT") \ + EM(netfs_sreq_trace_get_short_read, "GET SHORTRD") \ + EM(netfs_sreq_trace_new, "NEW ") \ + EM(netfs_sreq_trace_put_clear, "PUT CLEAR ") \ + EM(netfs_sreq_trace_put_failed, "PUT FAILED ") \ + EM(netfs_sreq_trace_put_merged, "PUT MERGED ") \ + EM(netfs_sreq_trace_put_no_copy, "PUT NO COPY") \ + E_(netfs_sreq_trace_put_terminated, "PUT TERM ") + #ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY #define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY @@ -77,6 +88,7 @@ enum netfs_rreq_trace { netfs_rreq_traces } __mode(byte); enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte); enum netfs_failure { netfs_failures } __mode(byte); enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte); +enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte); #endif @@ -94,6 +106,7 @@ netfs_sreq_sources; netfs_sreq_traces; netfs_failures; netfs_rreq_ref_traces; +netfs_sreq_ref_traces; /* * Now redefine the EM() and E_() macros to map the enums to the strings that @@ -264,6 +277,33 @@ TRACE_EVENT(netfs_rreq_ref, __entry->ref) ); +TRACE_EVENT(netfs_sreq_ref, + TP_PROTO(unsigned int rreq_debug_id, unsigned int subreq_debug_index, + int ref, enum netfs_sreq_ref_trace what), + + TP_ARGS(rreq_debug_id, subreq_debug_index, ref, what), + + TP_STRUCT__entry( + __field(unsigned int, rreq ) + __field(unsigned int, subreq ) + __field(int, ref ) + __field(enum netfs_sreq_ref_trace, what ) + ), + + TP_fast_assign( + __entry->rreq = rreq_debug_id; + __entry->subreq = subreq_debug_index; + __entry->ref = ref; + __entry->what = what; + ), + + TP_printk("R=%08x[%x] %s r=%u", + __entry->rreq, + __entry->subreq, + __print_symbolic(__entry->what, netfs_sreq_ref_traces), + __entry->ref) + ); + #undef EM #undef E_ #endif /* _TRACE_NETFS_H */