diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/volumes.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 6cb82f62cb7c..7c538f65214b 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -508,6 +508,33 @@ static noinline int device_list_add(const char *path, ret = 1; device->fs_devices = fs_devices; } else if (!device->name || strcmp(device->name->str, path)) { + /* + * When FS is already mounted. + * 1. If you are here and if the device->name is NULL that + * means this device was missing at time of FS mount. + * 2. If you are here and if the device->name is different + * from 'path' that means either + * a. The same device disappeared and reappeared with + * different name. or + * b. The missing-disk-which-was-replaced, has + * reappeared now. + * + * We must allow 1 and 2a above. But 2b would be a spurious + * and unintentional. + * + * Further in case of 1 and 2a above, the disk at 'path' + * would have missed some transaction when it was away and + * in case of 2a the stale bdev has to be updated as well. + * 2b must not be allowed at all time. + */ + + /* + * As of now don't allow update to btrfs_fs_device through + * the btrfs dev scan cli, after FS has been mounted. + */ + if (fs_devices->opened) + return -EBUSY; + name = rcu_string_strdup(path, GFP_NOFS); if (!name) return -ENOMEM; |