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| 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/dev-replace.c | |
| parent | 1776ad172e1ff09d4aa57daac74c56b4e1b0c636 (diff) | |
| download | linux-668e48af7a94985be7cf3b97a860d9819271d8bf.tar.gz linux-668e48af7a94985be7cf3b97a860d9819271d8bf.tar.bz2 linux-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 'fs/btrfs/dev-replace.c')
| -rw-r--r-- | fs/btrfs/dev-replace.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index f639dde2a679..8600beb9c086 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -707,6 +707,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, /* replace the sysfs entry */ btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); + btrfs_sysfs_update_devid(tgt_device); btrfs_rm_dev_replace_free_srcdev(src_device); /* write back the superblocks */ |