diff options
| author |   Anand Jain <anand.jain@oracle.com> | 2020-01-06 19:38:31 +0800 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2020-01-23 17:24:36 +0100 |
| commit | 668e48af7a94985be7cf3b97a860d9819271d8bf (patch) | |
| tree | 94ce292079f07595b6f490b33b3b1f01e4a7b655 /fs/btrfs/volumes.h | |
| parent | btrfs: Refactor btrfs_rmap_block to improve readability (diff) | |
| download | linux-dev-668e48af7a94985be7cf3b97a860d9819271d8bf.tar.xz linux-dev-668e48af7a94985be7cf3b97a860d9819271d8bf.zip | |
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 '')
| -rw-r--r-- | fs/btrfs/volumes.h | 4 |
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; }; /* |