From patchwork Mon Jan 20 19:49:25 2025 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: 858867 Received: from fgw23-4.mail.saunalahti.fi (fgw23-4.mail.saunalahti.fi [62.142.5.110]) (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 8997F1EEA51 for ; Mon, 20 Jan 2025 19:50:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.142.5.110 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737402627; cv=none; b=DOWgnBNa86CcXRhck1Jok+PFTyCPpygcuXEUbaRAEctNhiioR63BZVj7QQGIvbFoMcJ1i13bTsvtSR21o9cJTsZIW4r4LO3XrV1RxN+Z9yuEqumZuRIHkh0DS5zdMf/uvpwtOv54tClTTtC/Cb1es4IPVA7COkaFNT2bVk9lhi8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737402627; c=relaxed/simple; bh=KABGlaX7rMXucBqJq+MIXlqOLNLFyeYLI92Yrw0NLq8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CDOjuC2HLiOlw5TkK1QsQiGnMP563oO5a6IrLnJa7GTgfIYi3Hhd8K3WBvjhD18M2mp1RX2pTMGYakeTkVPuGB02tn7kbAw3tX/Ls2Vjv8GikF2HH5ghprrpJx4OHUAnHhccsJDzc5FGYJ87Id6kXqX2l+ooMBpFyv2WNYIc+ZU= 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=F6Bf9wgS; arc=none smtp.client-ip=62.142.5.110 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="F6Bf9wgS" 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=DtYdyyTFdl4qm+eN09b6vGlwUwXQ5lNR8Cz7Z4xR+JE=; b=F6Bf9wgSG3582uNDNDl/lJrM9AOAUSRJ6OLp9b+59J43Wq9PF2UmCNxIHkkasqbC3lsXh44+gRsCa Xy4jz5oQ2WixSojiQKNbNgSHOIqyEk6c6QEpKXJ7QZpwkh8bNTbaTVE5bmyjqHbJcY6wApcXyqdFt8 6vTiElvajYAKtqJPiPEoE4z9aACEgsqy1FQPfvRnsGV0ExTrk4YkCKOFluSf29H+r2LWu1jMPFcHGN gm+rMky85KdYKR7qNElPjhoshc1CQCUpHz3QsojmpgIQk2sN0EpZOu3kvh216NeYU2UgUeRNueasWQ lh2aCDeWhj9EYrwa9n/o06Oet6wtPLQ== 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 c3568288-d767-11ef-88a3-005056bdd08f; Mon, 20 Jan 2025 21:50:13 +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 v3 4/4] scsi: st: Add sysfs file reset_blocked Date: Mon, 20 Jan 2025 21:49:25 +0200 Message-ID: <20250120194925.44432-5-Kai.Makisara@kolumbus.fi> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250120194925.44432-1-Kai.Makisara@kolumbus.fi> References: <20250120194925.44432-1-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 6ec1cfeb92ff..e4fda0954004 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -4703,6 +4703,24 @@ 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 */ /** @@ -4887,6 +4905,7 @@ 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, };