From: Matteo Croce <mcroce@linux.microsoft.com>
To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
"Lennart Poettering" <lennart@poettering.net>,
"Luca Boccassi" <bluca@debian.org>,
"Jens Axboe" <axboe@kernel.dk>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Damien Le Moal" <damien.lemoal@wdc.com>,
"Tejun Heo" <tj@kernel.org>,
"Javier González" <javier@javigon.com>,
"Niklas Cassel" <niklas.cassel@wdc.com>,
"Johannes Thumshirn" <johannes.thumshirn@wdc.com>,
"Hannes Reinecke" <hare@suse.de>
Subject: [PATCH -next 4/5] block: export diskseq in sysfs
Date: Mon, 15 Mar 2021 21:02:41 +0100 [thread overview]
Message-ID: <20210315200242.67355-5-mcroce@linux.microsoft.com> (raw)
In-Reply-To: <20210315200242.67355-1-mcroce@linux.microsoft.com>
From: Matteo Croce <mcroce@microsoft.com>
Add a new sysfs handle to export the new diskseq value.
Place it in <sysfs>/block/<disk>/diskseq and document it.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
---
Documentation/ABI/testing/sysfs-block | 12 ++++++++++++
block/genhd.c | 11 +++++++++++
2 files changed, 23 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index e34cdeeeb9d4..a0ed87386639 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -28,6 +28,18 @@ Description:
For more details refer Documentation/admin-guide/iostats.rst
+What: /sys/block/<disk>/diskseq
+Date: February 2021
+Contact: Matteo Croce <mcroce@microsoft.com>
+Description:
+ The /sys/block/<disk>/diskseq files reports the disk
+ sequence number, which is a monotonically increasing
+ number assigned to every drive.
+ Some devices, like the loop device, refresh such number
+ every time the backing file is changed.
+ The value type is 64 bit unsigned.
+
+
What: /sys/block/<disk>/<part>/stat
Date: February 2008
Contact: Jerome Marchand <jmarchan@redhat.com>
diff --git a/block/genhd.c b/block/genhd.c
index 57d92ea7ae05..6a7ed426def0 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1764,6 +1764,7 @@ static void disk_check_events(struct disk_events *ev,
* events_async : list of events which can be detected w/o polling
* (always empty, only for backwards compatibility)
* events_poll_msecs : polling interval, 0: disable, -1: system default
+ * diskseq : disk sequence number, since boot
*/
static ssize_t __disk_events_show(unsigned int events, char *buf)
{
@@ -1834,16 +1835,26 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev,
return count;
}
+static ssize_t diskseq_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%llu\n", disk->diskseq);
+}
+
static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
static const DEVICE_ATTR(events_poll_msecs, 0644,
disk_events_poll_msecs_show,
disk_events_poll_msecs_store);
+static const DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
static const struct attribute *disk_sysfs_attrs[] = {
&dev_attr_events.attr,
&dev_attr_events_async.attr,
&dev_attr_events_poll_msecs.attr,
+ &dev_attr_diskseq.attr,
NULL,
};
--
2.30.2
next prev parent reply other threads:[~2021-03-15 20:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 20:02 [PATCH -next 0/5] block: add a sequence number to disks Matteo Croce
2021-03-15 20:02 ` [PATCH -next 1/5] block: add disk sequence number Matteo Croce
2021-03-15 20:18 ` Matthew Wilcox
2021-03-15 21:04 ` Matthew Wilcox
2021-03-15 21:32 ` Lennart Poettering
2021-03-25 17:29 ` Matteo Croce
2021-03-26 8:00 ` Hannes Reinecke
2021-03-25 20:58 ` Lennart Poettering
2021-03-16 14:13 ` Christoph Hellwig
2021-04-20 20:12 ` Lennart Poettering
2021-03-25 20:52 ` Lennart Poettering
2021-03-16 1:44 ` JeffleXu
2021-03-23 17:43 ` Matteo Croce
2021-03-15 20:02 ` [PATCH -next 2/5] block: add ioctl to read the " Matteo Croce
2021-03-15 20:13 ` Matthew Wilcox
2021-03-15 20:17 ` Damien Le Moal
2021-03-15 20:34 ` Matteo Croce
2021-03-15 20:02 ` [PATCH -next 3/5] block: refactor sysfs code Matteo Croce
2021-03-15 20:02 ` Matteo Croce [this message]
2021-03-15 20:02 ` [PATCH -next 5/5] loop: increment sequence number Matteo Croce
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