New sysfs attributes that track the filesystem status of devices, stored
in the per-filesystem directory in /sys/fs/btrfs/FSID/devinfo . There's
a directory for each device, with name corresponding to the numerical
device id.
in_fs_metadata - device is in the list of fs metadata
missing - device is missing (no device node or block device)
replace_target - device is target of replace
writeable - writes from fs are allowed
These attributes reflect the state of the device::dev_state and created
at mount time.
Sample output:
$ pwd
/sys/fs/btrfs/6e1961f1-5918-4ecc-a22f-948897b409f7/devinfo/1/
$ ls
in_fs_metadata missing replace_target writeable
$ cat missing
0
The output from these attributes are 0 or 1. 0 indicates unset and 1
indicates set. These attributes are readonly.
It is observed that the device delete thread and sysfs read thread will
not race because the delete thread calls sysfs kobject_put() which in
turn waits for existing sysfs read to complete.
Note for device replace devid swap:
During the replace the target device temporarily assumes devid 0 before
assigning the devid of the soruce device.
In btrfs_dev_replace_finishing() we remove source sysfs devid using the
function btrfs_sysfs_remove_devices_attr(), so after that call
kobject_rename() to update the devid in the sysfs. This adds and calls
btrfs_sysfs_update_devid() helper function to update the device id.
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
---
v5: squash [PATCH] btrfs: update devid after replace
import changes as in misc-next
changelog
rename btrfs_sysfs_xx to btrfs_devinfo_xx
reorder devinfo attributes
relocate btrfs_sysfs_update_devid with in sysfs.c
add device in the title
rename btrfs_sysfs_missing_show to btrfs_devinfo_missing_show
v4:
after patch
[PATCH v5 2/2] btrfs: reset device back to allocation state when removing
in misc-next, the device::devid_kobj remains stale, fix it by using
release.
v3:
Use optional groupid devid in BTRFS_ATTR(), it was blank in v2.
V2:
Make the devinfo attribute to carry one parameter, so now
instead of dev_state attribute, we create in_fs_metadata,
writeable, missing and replace_target attributes.
---
fs/btrfs/dev-replace.c | 1 +
fs/btrfs/sysfs.c | 155 +++++++++++++++++++++++++++++++++++------
fs/btrfs/sysfs.h | 1 +
fs/btrfs/volumes.h | 4 ++
4 files changed, 138 insertions(+), 23 deletions(-)
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 13a4ebd04a7a..131d23de5f64 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -744,6 +744,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
/* replace the sysfs entry */
btrfs_sysfs_remove_devices_attr(fs_info->fs_devices, src_device);
+ btrfs_sysfs_update_devid(tgt_device);
btrfs_rm_dev_replace_free_srcdev(src_device);
/* write back the superblocks */
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 10b9bc551330..364c0db36a3f 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1158,29 +1158,117 @@ int btrfs_sysfs_remove_devices_attr(struct btrfs_fs_devices *fs_devices,
if (!fs_devices->devices_kobj)
return -EINVAL;
- if (one_device && one_device->bdev) {
- disk = one_device->bdev->bd_part;
- disk_kobj = &part_to_dev(disk)->kobj;
+ if (one_device) {
+ if (one_device->bdev) {
+ disk = one_device->bdev->bd_part;
+ disk_kobj = &part_to_dev(disk)->kobj;
+ sysfs_remove_link(fs_devices->devices_kobj,
+ disk_kobj->name);
+ }
- sysfs_remove_link(fs_devices->devices_kobj, disk_kobj->name);
- }
+ kobject_del(&one_device->devid_kobj);
+ kobject_put(&one_device->devid_kobj);
+
+ wait_for_completion(&one_device->kobj_unregister);
- if (one_device)
return 0;
+ }
- list_for_each_entry(one_device,
- &fs_devices->devices, dev_list) {
- if (!one_device->bdev)
- continue;
- disk = one_device->bdev->bd_part;
- disk_kobj = &part_to_dev(disk)->kobj;
+ list_for_each_entry(one_device, &fs_devices->devices, dev_list) {
+
+ if (one_device->bdev) {
+ disk = one_device->bdev->bd_part;
+ disk_kobj = &part_to_dev(disk)->kobj;
+ sysfs_remove_link(fs_devices->devices_kobj,
+ disk_kobj->name);
+ }
+ kobject_del(&one_device->devid_kobj);
+ kobject_put(&one_device->devid_kobj);
- sysfs_remove_link(fs_devices->devices_kobj, disk_kobj->name);
+ wait_for_completion(&one_device->kobj_unregister);
}
return 0;
}
+static ssize_t btrfs_devinfo_in_fs_metadata_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_IN_FS_METADATA, &device->dev_state);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
+
+static ssize_t btrfs_devinfo_missing_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_MISSING, &device->dev_state);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
+
+static ssize_t btrfs_devinfo_replace_target_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_REPLACE_TGT, &device->dev_state);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
+
+static ssize_t btrfs_devinfo_writeable_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_WRITEABLE, &device->dev_state);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
+
+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),
+ NULL
+};
+ATTRIBUTE_GROUPS(devid);
+
+static void btrfs_release_devid_kobj(struct kobject *kobj)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ memset(&device->devid_kobj, 0, sizeof(struct kobject));
+ complete(&device->kobj_unregister);
+}
+
+static struct kobj_type devid_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = devid_groups,
+ .release = btrfs_release_devid_kobj,
+};
+
int btrfs_sysfs_add_devices_attr(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *one_device)
{
@@ -1188,22 +1276,31 @@ int btrfs_sysfs_add_devices_attr(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *dev;
list_for_each_entry(dev, &fs_devices->devices, dev_list) {
- struct hd_struct *disk;
- struct kobject *disk_kobj;
-
- if (!dev->bdev)
- continue;
if (one_device && one_device != dev)
continue;
- disk = dev->bdev->bd_part;
- disk_kobj = &part_to_dev(disk)->kobj;
+ if (dev->bdev) {
+ struct hd_struct *disk;
+ struct kobject *disk_kobj;
+
+ disk = dev->bdev->bd_part;
+ disk_kobj = &part_to_dev(disk)->kobj;
+
+ error = sysfs_create_link(fs_devices->devices_kobj,
+ disk_kobj, disk_kobj->name);
+ if (error)
+ break;
+ }
- error = sysfs_create_link(fs_devices->devices_kobj,
- disk_kobj, disk_kobj->name);
- if (error)
+ init_completion(&dev->kobj_unregister);
+ error = kobject_init_and_add(&dev->devid_kobj, &devid_ktype,
+ fs_devices->devinfo_kobj, "%llu",
+ dev->devid);
+ if (error) {
+ kobject_put(&dev->devid_kobj);
break;
+ }
}
return error;
@@ -1235,6 +1332,18 @@ void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
"sysfs: failed to create fsid for sprout");
}
+void btrfs_sysfs_update_devid(struct btrfs_device *device)
+{
+ char tmp[24];
+
+ snprintf(tmp, sizeof(tmp), "%llu", device->devid);
+
+ if (kobject_rename(&device->devid_kobj, tmp))
+ btrfs_warn(device->fs_devices->fs_info,
+ "sysfs: failed to update devid for %llu",
+ device->devid);
+}
+
/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;
diff --git a/fs/btrfs/sysfs.h b/fs/btrfs/sysfs.h
index 9d97b3c8db4e..ccf33eaf9e59 100644
--- a/fs/btrfs/sysfs.h
+++ b/fs/btrfs/sysfs.h
@@ -34,5 +34,6 @@ void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache);
int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info);
void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info);
+void btrfs_sysfs_update_devid(struct btrfs_device *device);
#endif
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 98535f1e208e..309cda477589 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -136,6 +136,10 @@ struct btrfs_device {
atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
struct extent_io_tree alloc_state;
+
+ struct completion kobj_unregister;
+ /* For sysfs/FSID/devinfo/devid/ */
+ struct kobject devid_kobj;
};
/*
--
2.23.0
