From: Anand Jain <anand.jain@oracle.com>
To: linux-btrfs@vger.kernel.org
Cc: dsterba@suse.com, josef@toxicpanda.com
Subject: [PATCH v4 2/3] btrfs: introduce new device-state read_preferred
Date: Tue, 19 Jan 2021 23:52:06 -0800 [thread overview]
Message-ID: <151811057c559d9212c7fc55e9c9cbbad1f62f05.1611114341.git.anand.jain@oracle.com> (raw)
In-Reply-To: <cover.1611114341.git.anand.jain@oracle.com>
This is a preparatory patch and introduces a new device flag
'read_preferred', RW-able using sysfs interface.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v4: -
v2: C style fixes. Drop space in between '! test_bit' and extra lines
after it.
fs/btrfs/sysfs.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 1 +
2 files changed, 54 insertions(+)
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 7c0324fe97b2..5888e15e3d14 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1422,11 +1422,64 @@ static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
}
BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
+static ssize_t btrfs_devinfo_read_pref_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ int val;
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ val = !!test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t btrfs_devinfo_read_pref_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ int ret;
+ unsigned long val;
+ struct btrfs_device *device;
+
+ ret = kstrtoul(skip_spaces(buf), 0, &val);
+ if (ret)
+ return ret;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ /*
+ * lock is not required, the btrfs_device struct can't be freed while
+ * its kobject btrfs_device::devid_kobj is still open.
+ */
+ device = container_of(kobj, struct btrfs_device, devid_kobj);
+
+ if (val &&
+ !test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state)) {
+ set_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state);
+ btrfs_info(device->fs_devices->fs_info,
+ "set read preferred on devid %llu (%d)",
+ device->devid, task_pid_nr(current));
+ } else if (!val &&
+ test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state)) {
+ clear_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state);
+ btrfs_info(device->fs_devices->fs_info,
+ "reset read preferred on devid %llu (%d)",
+ device->devid, task_pid_nr(current));
+ }
+
+ return len;
+}
+BTRFS_ATTR_RW(devid, read_preferred, btrfs_devinfo_read_pref_show,
+ btrfs_devinfo_read_pref_store);
+
static struct attribute *devid_attrs[] = {
BTRFS_ATTR_PTR(devid, in_fs_metadata),
BTRFS_ATTR_PTR(devid, missing),
BTRFS_ATTR_PTR(devid, replace_target),
BTRFS_ATTR_PTR(devid, writeable),
+ BTRFS_ATTR_PTR(devid, read_preferred),
NULL
};
ATTRIBUTE_GROUPS(devid);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 71ba1f0e93f4..ea786864b903 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -51,6 +51,7 @@ struct btrfs_io_geometry {
#define BTRFS_DEV_STATE_REPLACE_TGT (3)
#define BTRFS_DEV_STATE_FLUSH_SENT (4)
#define BTRFS_DEV_STATE_NO_READA (5)
+#define BTRFS_DEV_STATE_READ_PREFERRED (6)
struct btrfs_zoned_device_info;
--
2.28.0
next prev parent reply other threads:[~2021-01-20 7:55 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-20 7:52 [PATCH v4 0/3] btrfs: read_policy types latency, device and round-robin Anand Jain
2021-01-20 7:52 ` [PATCH v4 1/3] btrfs: add read_policy latency Anand Jain
2021-01-20 12:14 ` David Sterba
2021-01-21 10:10 ` Anand Jain
2021-01-21 17:52 ` David Sterba
2021-01-22 8:10 ` Anand Jain
2021-01-30 1:08 ` Anand Jain
2021-02-04 12:30 ` Anand Jain
2021-02-09 21:12 ` Michal Rostecki
2021-02-10 6:14 ` Anand Jain
2021-01-20 7:52 ` Anand Jain [this message]
2021-01-21 10:19 ` [PATCH v4 2/3] btrfs: introduce new device-state read_preferred Anand Jain
2021-01-20 7:52 ` [PATCH v4 3/3] btrfs: introduce new read_policy device Anand Jain
2021-01-20 12:34 ` [PATCH v4 0/3, full-cover-letter] btrfs: read_policy types latency, device and round-robin Anand Jain
2021-01-22 5:52 ` Anand Jain
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