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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD0F8CDB465 for ; Mon, 16 Oct 2023 14:44:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4A7618E0008; Mon, 16 Oct 2023 10:44:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 457BE8E0001; Mon, 16 Oct 2023 10:44:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31F4A8E0008; Mon, 16 Oct 2023 10:44:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 22C158E0001 for ; Mon, 16 Oct 2023 10:44:33 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id EA551160335 for ; Mon, 16 Oct 2023 14:44:32 +0000 (UTC) X-FDA: 81351595584.11.63825C2 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf08.hostedemail.com (Postfix) with ESMTP id 157D316000B for ; Mon, 16 Oct 2023 14:44:29 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=pbL0JENl; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf08.hostedemail.com: domain of jlayton@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=jlayton@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1697467470; h=from:from:sender: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:dkim-signature; bh=NcyihxwG8Z3tmdpJ0MQZUM2n56KMLni6f2Yrs+r7NkA=; b=qQUyT6XjkEwR8MG666UFcnhrkHIncZY6JXM612/ofnwdwigpRRKCTW4NX/x/pzHZEeLNJ7 T0nP71QTguk1NGWR82N0sUrrbUTRSJmzkXdOssGeNrg6XOB0nnkcWMEVFkULBmGwoTXb3Q SbindMQsgUR7wl5GO4r+FlL5T6mLaxs= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=pbL0JENl; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf08.hostedemail.com: domain of jlayton@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=jlayton@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1697467470; a=rsa-sha256; cv=none; b=tAhB1LSBmpSg5fxDkQjdpYKK1TZykY9zA2Pi4zrOyDSt+V2HkUzToExD/kzuHqiKQfPpQq GUM3ZCf1MTLYQvq6Rs9drsoZKWudDG0CBOGYlq9ehWgbRUO1LXy+LgFZkUkf94jh6d98j/ wIVL0ONhgZR6IZ+yG9SzDANV/Ge+RlI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id E204CB81617; Mon, 16 Oct 2023 14:44:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65C62C433C7; Mon, 16 Oct 2023 14:44:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697467467; bh=EosIPRQRkZS/m8fRSYLf1GF9E5dQpYw/H0GO2FrhMzU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=pbL0JENlz5RnGYP4I9kBXyy7y5PAbYeNgIvdEtdEfV+6JtSnYAgZxXfj6QS0OTvnq 7EQLcIfg5sdun4AKj6ILT0f9Sn+Lj6uvsAiodPVGiYDgFZBItlIo32ZAZ94e+7xhcC EzgeCAxFRNF1lIZMxpTdwOblh/UZLmbq4cioT65oxIZDzZFXQX7uvm9EQBD1jalFt1 7JjsKBkOkgur951+Esn3xom0VBOBX9uF/8bVz6kjKcDLzBtDl8aS9RlYKjQ/3DdqNd U2gH58YxGzyynaLl9ZTOovVYCLIQjHNnnlfnqltpw7WhZQlr1WcoivXsWgUIsn7mNI RHCnJAlJeYfQA== Message-ID: Subject: Re: [RFC PATCH 01/53] netfs: Add a procfile to list in-progress requests From: Jeff Layton To: David Howells , Steve French Cc: Matthew Wilcox , Marc Dionne , Paulo Alcantara , Ronnie Sahlberg , Shyam Prasad N , Tom Talpey , Dominique Martinet , Ilya Dryomov , Christian Brauner , 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, linux-cachefs@redhat.com Date: Mon, 16 Oct 2023 10:44:24 -0400 In-Reply-To: <20231013155727.2217781-2-dhowells@redhat.com> References: <20231013155727.2217781-1-dhowells@redhat.com> <20231013155727.2217781-2-dhowells@redhat.com> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.48.4 (3.48.4-1.fc38) MIME-Version: 1.0 X-Rspamd-Queue-Id: 157D316000B X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 5ibu8yqne6maasxqnuntjkpnciqyximg X-HE-Tag: 1697467469-926402 X-HE-Meta: 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 AQS66DYP s3Mpl/KRPK6hCKmOxvYtj7+0bL0wICEeZsrc/i2Zpkmg5KmT7SHpirkstQ7kZ2OdUbSmBCJqO7GkLzxv05Kk8S1kN3BEaqls9X9mcy7Kl/8xeNSo1Ey4fSlbCeRygWzMhRCRvY+rivm25gR6BUELllNo2EnT9bSNL/rGR1aOOPyH11z/1kjKamMwRmRwL7F3UF6/vVF4rMtBmNuKWUyb4+RNQCG6jBbp/1904xLVsst9sPSEgko1EV1pniY4fE5vrcQkwXBB9lYt0Vu/N+rtJceqoyNwBgxTc6oydOYbU92bmz1Wk7EDwj4tBSRPGqBFqJFQQxCaFxWcnbY4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 2023-10-13 at 16:56 +0100, David Howells wrote: > Add a procfile, /proc/fs/netfs/requests, to list in-progress netfslib I/O > requests. >=20 > 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 | 91 +++++++++++++++++++++++++++++++++++++++++++ > fs/netfs/objects.c | 4 +- > include/linux/netfs.h | 6 ++- > 4 files changed, 121 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h > index 43fac1b14e40..1f067aa96c50 100644 > --- a/fs/netfs/internal.h > +++ b/fs/netfs/internal.h > @@ -29,6 +29,28 @@ int netfs_begin_read(struct netfs_io_request *rreq, bo= ol 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 > =20 > /* > * objects.c > diff --git a/fs/netfs/main.c b/fs/netfs/main.c > index 068568702957..21f814eee6af 100644 > --- a/fs/netfs/main.c > +++ b/fs/netfs/main.c > @@ -7,6 +7,8 @@ > =20 > #include > #include > +#include > +#include > #include "internal.h" > #define CREATE_TRACE_POINTS > #include > @@ -18,3 +20,92 @@ MODULE_LICENSE("GPL"); > 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[] =3D { > + [NETFS_READAHEAD] =3D "RA", > + [NETFS_READPAGE] =3D "RP", > + [NETFS_READ_FOR_WRITE] =3D "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 =3D=3D &netfs_io_requests) { > + seq_puts(m, > + "REQUEST OR REF FL ERR OPS COVERAGE\n" > + "=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D =3D=3D=3D =3D=3D =3D=3D=3D=3D =3D= =3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D\n" > + ); > + return 0; > + } > + > + rreq =3D 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 =3D { > + .start =3D netfs_requests_seq_start, > + .next =3D netfs_requests_seq_next, > + .stop =3D netfs_requests_seq_stop, > + .show =3D netfs_requests_seq_show, > +}; > +#endif /* CONFIG_PROC_FS */ > + > +static int __init netfs_init(void) > +{ > + if (!proc_mkdir("fs/netfs", NULL)) > + goto error; > + It seems like this should go under debugfs instead. > + if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, > + &netfs_requests_seq_ops)) > + goto error_proc; > + > + return 0; > + > +error_proc: > + remove_proc_entry("fs/netfs", NULL); > +error: > + return -ENOMEM; > +} > +fs_initcall(netfs_init); > + > +static void __exit netfs_exit(void) > +{ > + remove_proc_entry("fs/netfs", NULL); > +} > +module_exit(netfs_exit); > 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 add= ress_space *mapping, > } > } > =20 > + 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 *wo= rk) > container_of(work, struct netfs_io_request, work); > =20 > 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); > } > =20 > diff --git a/include/linux/netfs.h b/include/linux/netfs.h > index b11a84f6c32b..b447cb67f599 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 tog= ether. > */ > 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; >=20 ACK on the general concept however. This is useful debugging info. --=20 Jeff Layton