path: root/fs/btrfs/volumes.h
diff options
authorAnand Jain <anand.jain@oracle.com>2020-01-06 19:38:31 +0800
committerDavid Sterba <dsterba@suse.com>2020-01-23 17:24:36 +0100
commit668e48af7a94985be7cf3b97a860d9819271d8bf (patch)
tree94ce292079f07595b6f490b33b3b1f01e4a7b655 /fs/btrfs/volumes.h
parentbtrfs: Refactor btrfs_rmap_block to improve readability (diff)
btrfs: sysfs, add devid/dev_state kobject and device attributes
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@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/volumes.h')
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 9c7d4fe5c39a..690d4f5a0653 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;