public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>
Subject: [PATCH 3/4] io-wq: allow lookup of existing io_wq with given id
Date: Thu, 23 Jan 2020 16:16:13 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

If the id and user/creds match, return an existing io_wq if we can safely
grab a reference to it.

Signed-off-by: Jens Axboe <[email protected]>
---
 fs/io-wq.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 fs/io-wq.h |  3 +++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 8cb0cff5f15c..a9985856033d 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -1024,7 +1024,7 @@ void io_wq_flush(struct io_wq *wq)
 	}
 }
 
-struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
+static struct io_wq *__io_wq_create(unsigned bounded, struct io_wq_data *data)
 {
 	int ret = -ENOMEM, node, id;
 	struct io_wq *wq;
@@ -1107,6 +1107,41 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
 	return ERR_PTR(ret);
 }
 
+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
+{
+	return __io_wq_create(bounded, data);
+}
+
+/*
+ * Find and return io_wq with given id and grab a reference to it.
+ */
+struct io_wq *io_wq_create_id(unsigned bounded, struct io_wq_data *data,
+			      unsigned int id)
+{
+	struct io_wq *wq, *ret = NULL;
+
+	mutex_lock(&wq_lock);
+	list_for_each_entry(wq, &wq_list, wq_list) {
+		if (id != wq->id)
+			continue;
+		if (data->creds != wq->creds || data->user != wq->user)
+			continue;
+		if (data->get_work != wq->get_work ||
+		    data->put_work != wq->put_work)
+			continue;
+		if (!refcount_inc_not_zero(&wq->use_refs))
+			continue;
+		ret = wq;
+		break;
+	}
+	mutex_unlock(&wq_lock);
+
+	if (!ret)
+		ret = io_wq_create(bounded, data);
+
+	return ret;
+}
+
 static bool io_wq_worker_wake(struct io_worker *worker, void *data)
 {
 	wake_up_process(worker->task);
@@ -1145,3 +1180,8 @@ void io_wq_destroy(struct io_wq *wq)
 		__io_wq_destroy(wq);
 	}
 }
+
+unsigned int io_wq_id(struct io_wq *wq)
+{
+	return wq->id;
+}
diff --git a/fs/io-wq.h b/fs/io-wq.h
index 1cd039af8813..7abe2c56b535 100644
--- a/fs/io-wq.h
+++ b/fs/io-wq.h
@@ -98,7 +98,10 @@ struct io_wq_data {
 };
 
 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
+struct io_wq *io_wq_create_id(unsigned bounded, struct io_wq_data *data,
+				unsigned int id);
 void io_wq_destroy(struct io_wq *wq);
+unsigned int io_wq_id(struct io_wq *wq);
 
 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
 void io_wq_enqueue_hashed(struct io_wq *wq, struct io_wq_work *work, void *val);
-- 
2.25.0


  parent reply	other threads:[~2020-01-23 23:16 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 23:16 [PATCHSET 0/4] Add support for shared io-wq backends Jens Axboe
2020-01-23 23:16 ` [PATCH 1/4] io-wq: make the io_wq ref counted Jens Axboe
2020-01-23 23:16 ` [PATCH 2/4] io-wq: add 'id' to io_wq Jens Axboe
2020-01-23 23:16 ` Jens Axboe [this message]
2020-01-24  9:54   ` [PATCH 3/4] io-wq: allow lookup of existing io_wq with given id Stefan Metzmacher
2020-01-24 16:41     ` Jens Axboe
2020-01-23 23:16 ` [PATCH 4/4] io_uring: add support for sharing kernel io-wq workqueue Jens Axboe
2020-01-24  9:51 ` [PATCHSET 0/4] Add support for shared io-wq backends Stefan Metzmacher
2020-01-24 16:43   ` Jens Axboe
2020-01-24 19:14     ` Stefan Metzmacher
2020-01-24 21:37       ` Jens Axboe
2020-01-24 20:34 ` Pavel Begunkov
2020-01-24 21:38   ` Jens Axboe
2020-01-26  1:51 ` Daurnimator
2020-01-26 15:11   ` Pavel Begunkov
2020-01-26 17:00     ` Jens Axboe
2020-01-27 13:29       ` Pavel Begunkov
2020-01-27 13:39         ` Jens Axboe
2020-01-27 14:07           ` Pavel Begunkov
2020-01-27 19:39             ` Pavel Begunkov
2020-01-27 19:45               ` Jens Axboe
2020-01-27 20:33             ` Jens Axboe
2020-01-27 21:45               ` Pavel Begunkov
2020-01-27 22:40                 ` Jens Axboe
2020-01-27 23:00                   ` Jens Axboe
2020-01-27 23:17                     ` Pavel Begunkov
2020-01-27 23:23                       ` Jens Axboe
2020-01-27 23:25                         ` Pavel Begunkov
2020-01-27 23:38                           ` Jens Axboe
2020-01-28 10:01                             ` Stefan Metzmacher
2020-01-28 10:30                               ` Pavel Begunkov
2020-01-28 10:35                                 ` Stefan Metzmacher
2020-01-28 10:51                                   ` Pavel Begunkov
  -- strict thread matches above, loose matches on Subject: below --
2020-01-24 21:31 [PATCHSET v2 " Jens Axboe
2020-01-24 21:31 ` [PATCH 3/4] io-wq: allow lookup of existing io_wq with given id Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox