From patchwork Wed Dec 13 15:23:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13491334 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EtuTPRUp" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95E2FEB for ; Wed, 13 Dec 2023 07:24:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702481064; 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=xXclU2RwEHr6/zRJbfo0avpxB2MmbXmM1O7VqBArdhM=; b=EtuTPRUpIwGM04qPcikPwp/dEVSUcLfXeDhcdfCON5h8LhtnTQqCXfbBKjv69vJosXtYMO bVDE4p3yN1EEU8k3WoK/DHhv0QZTT7p7s+52wqJYotrUKGAjUiXT9NAjwBxRJCXQ8YewKu u3TI7O/eaASy1GTszM/XfASs6XAwOxk= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-344-n_hhXb5pO6ysfAa7O8x7VQ-1; Wed, 13 Dec 2023 10:24:19 -0500 X-MC-Unique: n_hhXb5pO6ysfAa7O8x7VQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 430E41C05B02; Wed, 13 Dec 2023 15:24:18 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4C1982166B32; Wed, 13 Dec 2023 15:24:15 +0000 (UTC) From: David Howells To: Jeff Layton , Steve French Cc: David Howells , Matthew Wilcox , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Dominique Martinet , Eric Van Hensbergen , Ilya Dryomov , Christian Brauner , linux-cachefs@redhat.com, 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-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 06/39] netfs: Add a procfile to list in-progress requests Date: Wed, 13 Dec 2023 15:23:16 +0000 Message-ID: <20231213152350.431591-7-dhowells@redhat.com> In-Reply-To: <20231213152350.431591-1-dhowells@redhat.com> References: <20231213152350.431591-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Add a procfile, /proc/fs/netfs/requests, to list in-progress netfslib I/O requests. Signed-off-by: David Howells cc: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- fs/netfs/internal.h | 22 ++++++++++++++ fs/netfs/main.c | 69 ++++++++++++++++++++++++++++++++++++++++++- fs/netfs/objects.c | 4 ++- include/linux/netfs.h | 6 +++- 4 files changed, 98 insertions(+), 3 deletions(-) diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index a15fe67e1db7..937d9a22f178 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -33,6 +33,28 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync); * main.c */ extern unsigned int netfs_debug; +extern struct list_head netfs_io_requests; +extern spinlock_t netfs_proc_lock; + +#ifdef CONFIG_PROC_FS +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) +{ + spin_lock(&netfs_proc_lock); + list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests); + spin_unlock(&netfs_proc_lock); +} +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) +{ + if (!list_empty(&rreq->proc_link)) { + spin_lock(&netfs_proc_lock); + list_del_rcu(&rreq->proc_link); + spin_unlock(&netfs_proc_lock); + } +} +#else +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {} +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} +#endif /* * objects.c diff --git a/fs/netfs/main.c b/fs/netfs/main.c index c9af6e0896d3..97ce1436615b 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -21,13 +21,80 @@ unsigned netfs_debug; module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); +#ifdef CONFIG_PROC_FS +LIST_HEAD(netfs_io_requests); +DEFINE_SPINLOCK(netfs_proc_lock); + +static const char *netfs_origins[] = { + [NETFS_READAHEAD] = "RA", + [NETFS_READPAGE] = "RP", + [NETFS_READ_FOR_WRITE] = "RW", +}; + +/* + * Generate a list of I/O requests in /proc/fs/netfs/requests + */ +static int netfs_requests_seq_show(struct seq_file *m, void *v) +{ + struct netfs_io_request *rreq; + + if (v == &netfs_io_requests) { + seq_puts(m, + "REQUEST OR REF FL ERR OPS 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 %zx/%zx", + 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; +} + +static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) + __acquires(rcu) +{ + rcu_read_lock(); + return seq_list_start_head(&netfs_io_requests, *_pos); +} + +static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) +{ + return seq_list_next(v, &netfs_io_requests, _pos); +} + +static void netfs_requests_seq_stop(struct seq_file *m, void *v) + __releases(rcu) +{ + rcu_read_unlock(); +} + +static const struct seq_operations netfs_requests_seq_ops = { + .start = netfs_requests_seq_start, + .next = netfs_requests_seq_next, + .stop = netfs_requests_seq_stop, + .show = netfs_requests_seq_show, +}; +#endif /* CONFIG_PROC_FS */ + static int __init netfs_init(void) { int ret = -ENOMEM; if (!proc_mkdir("fs/netfs", NULL)) goto error; - + if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, + &netfs_requests_seq_ops)) + goto error_proc; #ifdef CONFIG_FSCACHE_STATS if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, netfs_stats_show)) diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index e17cdf53f6a7..85f428fc52e6 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -45,6 +45,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, } } + netfs_proc_add_rreq(rreq); netfs_stat(&netfs_n_rh_rreq); return rreq; } @@ -76,12 +77,13 @@ static void netfs_free_request(struct work_struct *work) container_of(work, struct netfs_io_request, work); trace_netfs_rreq(rreq, netfs_rreq_trace_free); + netfs_proc_del_rreq(rreq); netfs_clear_subrequests(rreq, false); if (rreq->netfs_ops->free_request) rreq->netfs_ops->free_request(rreq); if (rreq->cache_resources.ops) rreq->cache_resources.ops->end_operation(&rreq->cache_resources); - kfree(rreq); + kfree_rcu(rreq, rcu); netfs_stat_d(&netfs_n_rh_rreq); } diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 32faf6c89702..7244ddebd974 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -175,10 +175,14 @@ enum netfs_io_origin { * operations to a variety of data stores and then stitch the result together. */ struct netfs_io_request { - struct work_struct work; + union { + struct work_struct work; + struct rcu_head rcu; + }; struct inode *inode; /* The file being accessed */ struct address_space *mapping; /* The mapping being accessed */ struct netfs_cache_resources cache_resources; + struct list_head proc_link; /* Link in netfs_iorequests */ struct list_head subrequests; /* Contributory I/O operations */ void *netfs_priv; /* Private data for the netfs */ unsigned int debug_id;