From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, Jakub Kicinski <kuba@kernel.org>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 11/23] tun: honor IOCB_NOWAIT flag
Date: Thu, 3 Dec 2020 08:29:23 -0500 [thread overview]
Message-ID: <20201203132935.931362-11-sashal@kernel.org> (raw)
In-Reply-To: <20201203132935.931362-1-sashal@kernel.org>
From: Jens Axboe <axboe@kernel.dk>
[ Upstream commit 5aac0390a63b8718237a61dd0d24a29201d1c94a ]
tun only checks the file O_NONBLOCK flag, but it should also be checking
the iocb IOCB_NOWAIT flag. Any fops using ->read/write_iter() should check
both, otherwise it breaks users that correctly expect O_NONBLOCK semantics
if IOCB_NOWAIT is set.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/e9451860-96cc-c7c7-47b8-fe42cadd5f4c@kernel.dk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/tun.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 46bdd0df2eb8b..e72d273999834 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2028,12 +2028,15 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = tun_get(tfile);
ssize_t result;
+ int noblock = 0;
if (!tun)
return -EBADFD;
- result = tun_get_user(tun, tfile, NULL, from,
- file->f_flags & O_NONBLOCK, false);
+ if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT))
+ noblock = 1;
+
+ result = tun_get_user(tun, tfile, NULL, from, noblock, false);
tun_put(tun);
return result;
@@ -2254,10 +2257,15 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = tun_get(tfile);
ssize_t len = iov_iter_count(to), ret;
+ int noblock = 0;
if (!tun)
return -EBADFD;
- ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
+
+ if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT))
+ noblock = 1;
+
+ ret = tun_do_read(tun, tfile, to, noblock, NULL);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
--
2.27.0
next prev parent reply other threads:[~2020-12-03 13:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 13:29 [PATCH AUTOSEL 5.4 01/23] iwlwifi: pcie: limit memory read spin time Sasha Levin
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 03/23] iwlwifi: pcie: set LTR to avoid completion timeout Sasha Levin
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 04/23] iwlwifi: mvm: fix kernel panic in case of assert during CSA Sasha Levin
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 10/23] usbnet: ipheth: fix connectivity with iOS 14 Sasha Levin
2020-12-03 13:29 ` Sasha Levin [this message]
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 12/23] ibmvnic: skip tx timeout reset while in resetting Sasha Levin
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 22/23] can: m_can: m_can_dev_setup(): add support for bosch mcan version 3.3.0 Sasha Levin
2020-12-03 13:29 ` [PATCH AUTOSEL 5.4 23/23] can: af_can: can_rx_unregister(): remove WARN() statement from list operation sanity check Sasha Levin
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