From patchwork Wed Aug 21 17:37:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11107629 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A051814DE for ; Wed, 21 Aug 2019 17:39:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FA4C233A2 for ; Wed, 21 Aug 2019 17:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730237AbfHURiu (ORCPT ); Wed, 21 Aug 2019 13:38:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730001AbfHURiV (ORCPT ); Wed, 21 Aug 2019 13:38:21 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 28D082A09C5; Wed, 21 Aug 2019 17:38:21 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id E77AA60603; Wed, 21 Aug 2019 17:38:20 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id C95EF223D05; Wed, 21 Aug 2019 13:38:14 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu Cc: virtio-fs@redhat.com, vgoyal@redhat.com, stefanha@redhat.com, dgilbert@redhat.com, Miklos Szeredi Subject: [PATCH 09/13] fuse: add fuse_iqueue_ops callbacks Date: Wed, 21 Aug 2019 13:37:38 -0400 Message-Id: <20190821173742.24574-10-vgoyal@redhat.com> In-Reply-To: <20190821173742.24574-1-vgoyal@redhat.com> References: <20190821173742.24574-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 21 Aug 2019 17:38:21 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Stefan Hajnoczi The /dev/fuse device uses fiq->waitq and fasync to signal that requests are available. These mechanisms do not apply to virtio-fs. This patch introduces callbacks so alternative behavior can be used. Note that queue_interrupt() changes along these lines: spin_lock(&fiq->waitq.lock); wake_up_locked(&fiq->waitq); + kill_fasync(&fiq->fasync, SIGIO, POLL_IN); spin_unlock(&fiq->waitq.lock); - kill_fasync(&fiq->fasync, SIGIO, POLL_IN); Since queue_request() and queue_forget() also call kill_fasync() inside the spinlock this should be safe. Signed-off-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi --- fs/fuse/cuse.c | 2 +- fs/fuse/dev.c | 50 ++++++++++++++++++++++++++++++++---------------- fs/fuse/fuse_i.h | 48 +++++++++++++++++++++++++++++++++++++++++++++- fs/fuse/inode.c | 16 ++++++++++++---- 4 files changed, 94 insertions(+), 22 deletions(-) diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index bab7a0db81dd..7bdab6521469 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -504,7 +504,7 @@ static int cuse_channel_open(struct inode *inode, struct file *file) * Limit the cuse channel to requests that can * be represented in file->f_cred->user_ns. */ - fuse_conn_init(&cc->fc, file->f_cred->user_ns); + fuse_conn_init(&cc->fc, file->f_cred->user_ns, &fuse_dev_fiq_ops, NULL); fud = fuse_dev_alloc(&cc->fc); if (!fud) { diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 2bbfc1f77875..fa6794e96811 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -375,13 +375,33 @@ static unsigned int fuse_req_hash(u64 unique) return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS); } -static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req) +/** + * A new request is available, wake fiq->waitq + */ +static void fuse_dev_wake_and_unlock(struct fuse_iqueue *fiq) +__releases(fiq->waitq.lock) { - req->in.h.len = sizeof(struct fuse_in_header) + - fuse_len_args(req->in.numargs, (struct fuse_arg *) req->in.args); - list_add_tail(&req->list, &fiq->pending); wake_up_locked(&fiq->waitq); kill_fasync(&fiq->fasync, SIGIO, POLL_IN); + spin_unlock(&fiq->waitq.lock); +} + +const struct fuse_iqueue_ops fuse_dev_fiq_ops = { + .wake_forget_and_unlock = fuse_dev_wake_and_unlock, + .wake_interrupt_and_unlock = fuse_dev_wake_and_unlock, + .wake_pending_and_unlock = fuse_dev_wake_and_unlock, +}; +EXPORT_SYMBOL_GPL(fuse_dev_fiq_ops); + +static void queue_request_and_unlock(struct fuse_iqueue *fiq, + struct fuse_req *req) +__releases(fiq->waitq.lock) +{ + req->in.h.len = sizeof(struct fuse_in_header) + + fuse_len_args(req->in.numargs, + (struct fuse_arg *) req->in.args); + list_add_tail(&req->list, &fiq->pending); + fiq->ops->wake_pending_and_unlock(fiq); } void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, @@ -396,12 +416,11 @@ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, if (fiq->connected) { fiq->forget_list_tail->next = forget; fiq->forget_list_tail = forget; - wake_up_locked(&fiq->waitq); - kill_fasync(&fiq->fasync, SIGIO, POLL_IN); + fiq->ops->wake_forget_and_unlock(fiq); } else { kfree(forget); + spin_unlock(&fiq->waitq.lock); } - spin_unlock(&fiq->waitq.lock); } static void flush_bg_queue(struct fuse_conn *fc) @@ -417,8 +436,7 @@ static void flush_bg_queue(struct fuse_conn *fc) fc->active_background++; spin_lock(&fiq->waitq.lock); req->in.h.unique = fuse_get_unique(fiq); - queue_request(fiq, req); - spin_unlock(&fiq->waitq.lock); + queue_request_and_unlock(fiq, req); } } @@ -506,10 +524,10 @@ static int queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req) spin_unlock(&fiq->waitq.lock); return 0; } - wake_up_locked(&fiq->waitq); - kill_fasync(&fiq->fasync, SIGIO, POLL_IN); + fiq->ops->wake_interrupt_and_unlock(fiq); + } else { + spin_unlock(&fiq->waitq.lock); } - spin_unlock(&fiq->waitq.lock); return 0; } @@ -569,11 +587,10 @@ static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) req->out.h.error = -ENOTCONN; } else { req->in.h.unique = fuse_get_unique(fiq); - queue_request(fiq, req); /* acquire extra reference, since request is still needed after fuse_request_end() */ __fuse_get_request(req); - spin_unlock(&fiq->waitq.lock); + queue_request_and_unlock(fiq, req); request_wait_answer(fc, req); /* Pairs with smp_wmb() in fuse_request_end() */ @@ -706,10 +723,11 @@ static int fuse_request_send_notify_reply(struct fuse_conn *fc, req->in.h.unique = unique; spin_lock(&fiq->waitq.lock); if (fiq->connected) { - queue_request(fiq, req); + queue_request_and_unlock(fiq, req); err = 0; + } else { + spin_unlock(&fiq->waitq.lock); } - spin_unlock(&fiq->waitq.lock); return err; } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 062f929348cc..70c1bde06293 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -75,6 +75,12 @@ struct fuse_mount_data { unsigned max_read; unsigned blksize; + /* fuse input queue operations */ + const struct fuse_iqueue_ops *fiq_ops; + + /* device-specific state for fuse_iqueue */ + void *fiq_priv; + /* fuse_dev pointer to fill in, should contain NULL on entry */ void **fudptr; }; @@ -465,6 +471,39 @@ struct fuse_req { struct file *stolen_file; }; +struct fuse_iqueue; + +/** + * Input queue callbacks + * + * Input queue signalling is device-specific. For example, the /dev/fuse file + * uses fiq->waitq and fasync to wake processes that are waiting on queue + * readiness. These callbacks allow other device types to respond to input + * queue activity. + */ +struct fuse_iqueue_ops { + /** + * Signal that a forget has been queued + */ + void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq) + __releases(fiq->waitq.lock); + + /** + * Signal that an INTERRUPT request has been queued + */ + void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq) + __releases(fiq->waitq.lock); + + /** + * Signal that a request has been queued + */ + void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq) + __releases(fiq->waitq.lock); +}; + +/** /dev/fuse input queue operations */ +extern const struct fuse_iqueue_ops fuse_dev_fiq_ops; + struct fuse_iqueue { /** Connection established */ unsigned connected; @@ -490,6 +529,12 @@ struct fuse_iqueue { /** O_ASYNC requests */ struct fasync_struct *fasync; + + /** Device-specific callbacks */ + const struct fuse_iqueue_ops *ops; + + /** Device-specific state */ + void *priv; }; #define FUSE_PQ_HASH_BITS 8 @@ -1007,7 +1052,8 @@ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); /** * Initialize fuse_conn */ -void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns); +void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns, + const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv); /** * Release reference to fuse_conn diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9f21a0cb58b9..226af184a402 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -565,7 +565,9 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root) return 0; } -static void fuse_iqueue_init(struct fuse_iqueue *fiq) +static void fuse_iqueue_init(struct fuse_iqueue *fiq, + const struct fuse_iqueue_ops *ops, + void *priv) { memset(fiq, 0, sizeof(struct fuse_iqueue)); init_waitqueue_head(&fiq->waitq); @@ -573,6 +575,8 @@ static void fuse_iqueue_init(struct fuse_iqueue *fiq) INIT_LIST_HEAD(&fiq->interrupts); fiq->forget_list_tail = &fiq->forget_list_head; fiq->connected = 1; + fiq->ops = ops; + fiq->priv = priv; } static void fuse_pqueue_init(struct fuse_pqueue *fpq) @@ -586,7 +590,8 @@ static void fuse_pqueue_init(struct fuse_pqueue *fpq) fpq->connected = 1; } -void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns) +void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns, + const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) { memset(fc, 0, sizeof(*fc)); spin_lock_init(&fc->lock); @@ -596,7 +601,7 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns) atomic_set(&fc->dev_count, 1); init_waitqueue_head(&fc->blocked_waitq); init_waitqueue_head(&fc->reserved_req_waitq); - fuse_iqueue_init(&fc->iq); + fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); INIT_LIST_HEAD(&fc->bg_queue); INIT_LIST_HEAD(&fc->entry); INIT_LIST_HEAD(&fc->devices); @@ -1110,7 +1115,8 @@ int fuse_fill_super_common(struct super_block *sb, if (!fc) goto err; - fuse_conn_init(fc, sb->s_user_ns); + fuse_conn_init(fc, sb->s_user_ns, mount_data->fiq_ops, + mount_data->fiq_priv); fc->release = fuse_free_conn; fud = fuse_dev_alloc(fc); @@ -1212,6 +1218,8 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) goto err_fput; __set_bit(FR_BACKGROUND, &init_req->flags); + d.fiq_ops = &fuse_dev_fiq_ops; + d.fiq_priv = NULL; d.fudptr = &file->private_data; err = fuse_fill_super_common(sb, &d); if (err < 0)