From patchwork Mon Nov 25 14:03:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Kai_M=C3=A4kisara?= X-Patchwork-Id: 13884941 Received: from fgw22-4.mail.saunalahti.fi (fgw22-4.mail.saunalahti.fi [62.142.5.109]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6E5E192B7F for ; Mon, 25 Nov 2024 14:03:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.142.5.109 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732543432; cv=none; b=dAEGTzerhLiAoNBTY+lM4jGscgt28AvcN1zIJ1Pye53QMzHgeZdrbg2HefZxixOOlXMmZ6Z3E18VAnA5d8YkNAKFQOWBRHDq1jglKIWsIuM4Gs2UN9N4zRM8eUd9qCmG60J2w6D0n4oPmDBP6szNvAZKUMTjpvVUc1hYVXMVBIc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732543432; c=relaxed/simple; bh=3Go/PZyu/K4D4xKrpApeeRJrQZXrkB71scXFvQZQDOw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FB+7E7MfPaKpGfhM+A+ROznEOXwEY7I+Z9Usng0+ix/vfCH8Bu+8M3tY47zPlTckKgiKsQ6BuGx7gffcvMuT0pxb/EGOaWJSF6/ZLghDLzmcMGmkhcblXKTGEDVHMvdPdlhZokGMNUVs7DtfHwzJpiFBonkfTKt0dbg4qD13Wg4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kolumbus.fi; spf=pass smtp.mailfrom=kolumbus.fi; dkim=pass (2048-bit key) header.d=kolumbus.fi header.i=@kolumbus.fi header.b=Lcm8r229; arc=none smtp.client-ip=62.142.5.109 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kolumbus.fi Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kolumbus.fi Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kolumbus.fi header.i=@kolumbus.fi header.b="Lcm8r229" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kolumbus.fi; s=elisa1; h=content-transfer-encoding:content-type:mime-version:references:in-reply-to: message-id:date:subject:cc:to:from:from:to:cc:reply-to:subject:date: in-reply-to:references:list-archive:list-subscribe:list-unsubscribe: content-type:content-transfer-encoding:message-id; bh=NeqVt7amgvIxmptxFb8tKAWnqzkJFXJev23JSQNq7aw=; b=Lcm8r229ixtrKrKborSvcEAVWeBY4FNnC/gubLuM9fefkH9EOzmC2e6C1NezVDWIM3eu4KNNGItuY qbBT4C5t3DygPLTYHmR8wb1ARnx9H9KKsZQL5ucfkYekRJYvD/C9U6Q86QQ0+J0BlVBoeIJz5TtGa/ R9DlSviSRd61wWgujXrJYccfs5wSkOGUTeUeNNIULthKL7DCq+SK727fvXotOeaEgYti5KCsYiKnPo 91wF/g1sGiGQGyWWxeD5yORR08IojGcAFRUv90jXkyEazKwXCd2WmNngtXTIam+I2A2NAzWTG2MzTG kxE2vS3ZrHPLBUqzvvw2pWvVORue5TQ== Received: from kaipn1.makisara.private (85-156-116-90.elisa-laajakaista.fi [85.156.116.90]) by fgw21.mail.saunalahti.fi (Halon) with ESMTPSA id 0837c1a6-ab36-11ef-8882-005056bdd08f; Mon, 25 Nov 2024 16:03:22 +0200 (EET) From: =?utf-8?q?Kai_M=C3=A4kisara?= To: linux-scsi@vger.kernel.org, jmeneghi@redhat.com Cc: martin.petersen@oracle.com, James.Bottomley@HansenPartnership.com, loberman@redhat.com, =?utf-8?q?Kai_M=C3=A4kisara?= Subject: [PATCH v2 4/4] scsi: st: Add sysfs file reset_blocked Date: Mon, 25 Nov 2024 16:03:01 +0200 Message-ID: <20241125140301.3912-5-Kai.Makisara@kolumbus.fi> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241125140301.3912-1-Kai.Makisara@kolumbus.fi> References: <20241125140301.3912-1-Kai.Makisara@kolumbus.fi> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If the value read from the file is 1, reads and writes from/to the device are blocked because the tape position may not match user's expectation (tape rewound after device reset). Signed-off-by: Kai Mäkisara --- Documentation/scsi/st.rst | 5 +++++ drivers/scsi/st.c | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/Documentation/scsi/st.rst b/Documentation/scsi/st.rst index d3b28c28d74c..2209f03faad3 100644 --- a/Documentation/scsi/st.rst +++ b/Documentation/scsi/st.rst @@ -157,6 +157,11 @@ enabled driver and mode options. The value in the file is a bit mask where the bit definitions are the same as those used with MTSETDRVBUFFER in setting the options. +Each directory contains the entry 'reset_blocked'. If this value is one, +reading and writing to the device is blocked after device reset. Most +devices rewind the tape after reset and the writes/read don't access the +tape position the user expects. + A link named 'tape' is made from the SCSI device directory to the class directory corresponding to the mode 0 auto-rewind device (e.g., st0). diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index ad86dfbc8919..0e6a87f1f47f 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -4697,6 +4697,24 @@ options_show(struct device *dev, struct device_attribute *attr, char *buf) } static DEVICE_ATTR_RO(options); +/** + * reset_blocked_show - Value 1 indicates that reads, writes, etc. are blocked + * because a device reset has occurred and no operation positioning the tape + * has been issued. + * @dev: struct device + * @attr: attribute structure + * @buf: buffer to return formatted data in + */ +static ssize_t reset_blocked_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct st_modedef *STm = dev_get_drvdata(dev); + struct scsi_tape *STp = STm->tape; + + return sprintf(buf, "%d", STp->pos_unknown); +} +static DEVICE_ATTR_RO(reset_blocked); + /* Support for tape stats */ /** @@ -4881,6 +4899,7 @@ static struct attribute *st_dev_attrs[] = { &dev_attr_default_density.attr, &dev_attr_default_compression.attr, &dev_attr_options.attr, + &dev_attr_reset_blocked.attr, NULL, };